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Примеры страниц (скриншоты)

Оглавление

First Things First ix
Chapter 1: Essential Concepts 19
What’s Linux? 19
The Structure of Commands 24
Users and Superusers 26
The Filesystem 27
Selected Features of Bash 36
Getting Help 59
Chapter 2: File Commands 61
Basic File Operations 61
Directory Operations 68
Viewing Files 71
Creating and Editing Files 78
Properties of Files 83
Locating Files 97
Manipulating Text in Files 107
Compressing, Packaging, and Encrypting 126
Comparing Files 135
Converting Files to Other Formats 140
PDF and PostScript File Handling 151
Printing 156
Spellchecking 158
Chapter 3: System Administration Basics 161
Becoming the Superuser 161
Viewing Processes 163
Controlling Processes 169
Scheduling Jobs 175
Logins, Logouts, and Shutdowns 181
Users and Their Environment 184
User Account Management 188
Group Management 192
Installing Software Packages 195
Installing Software from Source Code 209
Chapter 4: Filesystem Maintenance 213
Using Disks and Filesystems 213
Creating and Modifying Filesystems 219
RAID Arrays for Redundancy 224
Logical Volumes for Flexible Storage 229
ZFS: A Modern, Do-It-All Filesystem 235
Backups and Remote Storage 241
Chapter 5: Networking Commands 249
Host Information 249
Host Location 252
Network Connections 256
Email in Daily Use 262
Email Servers 266
Web Browsing 270
Chapter 6: Getting Stuff Done 275
Screen Output 275
Copy and Paste 281
Math and Calculations 283
Dates and Times 289
Version Control 292
Containers 297
Displaying and Processing Images 301
Audio and Video 303
Programming with Shell Scripts 311
Final Words 328
Index 329

Примеры страниц (скриншоты)

Оглавление

Table of Contents 3
Preface 15
About the Author 16
Introduction 17
Original Training Course Name 17
Prerequisites 18
Training Goals 19
Training Principles 20
Schedule 21
Training Idea 22
General C & C++ Aspects 23
What We Do Not Cover 25
Linux C & C++ Aspects 26
Why C & C++? 27
Which C & C++? 29
My History of C & C++ 30
C and C++ Mastery Process 32
Thought Process 33
Philosophy of Pointers 34
Pointer 35
Pointer Dereference 36
Many to One 37
Many to One Dereference 38
Invalid Pointer 39
Invalid Pointer Dereference 40
Wild (Dangling) Pointer 41
Pointer to Pointer 42
Pointer to Pointer Dereference 43
Naming Pointers and Entities 44
Names as Pointer Content 45
Pointers as Entities 46
Memory and Pointers 47
Mental Exercise 48
Debugger Memory Layout 49
Memory Dereference Layout 50
Names as Addresses 51
Addresses and Entities 52
Addresses and Structures 53
Pointers to Structures 54
Arrays 55
Arrays and Pointers to Arrays 56
Strings and Pointers to Strings 57
Basic Types 58
ASCII Characters and Pointers 59
Bytes and Pointers 60
Wide Characters and Pointers 61
Integers 62
Little-Endian System 63
Short Integers 64
Long and Long Long Integers 65
Signed and Unsigned Integers 66
Fixed Size Integers 67
Booleans 68
Bytes 69
Size 70
Alignment 71
LP64 72
Nothing and Anything 73
Automatic Type Inference 74
Entity Conversion 75
Pointer Conversion (C-Style) 76
Numeric Promotion/Conversion 77
Numeric Conversion 78
Incompatible Types 79
Forcing 80
Structures, Classes, and Objects 82
Structures 83
Access Level 84
Classes and Objects 85
Structures and Classes 86
Pointer to Structure 87
Pointer to Structure Dereference 88
Many Pointers to One Structure 89
Many to One Dereference 90
Invalid Pointer to Structure 91
Invalid Pointer Dereference 92
Wild (Dangling) Pointer 93
Pointer to Pointer to Structure 94
Pointer to Pointer Dereference 95
Memory and Structures 96
Addresses and Structures 97
Structure Field Access 98
Pointers to Structures 99
Pointers to Structure Fields 100
Structure Inheritance 101
Structure Slicing 102
Inheritance Access Level 104
Structures and Classes II 105
Internal Structure Alignment 106
Static Structure Fields 107
Uniform Initialization 108
Old Initialization Ways 109
New Way {} 110
Uniform Structure Initialization 111
Static Field Initialization 112
Macros, Types, and Synonyms 113
Macros 114
Old Way 115
New Way 116
Memory Storage 117
Overview 118
Thread Stack Frames 119
Local Variable Value Lifecycle 120
Stack Allocation Pitfalls 122
Explicit Local Allocation 124
Dynamic Allocation (C-style) 125
Dynamic Allocation (C++) 126
Memory Operators 127
Memory Expressions 128
Local Pointers (Manual) 129
In-place Allocation 131
Source Code Organisation 132
Logical Layer (Translation Units) 133
Physical Layer (Source Files) 134
Inter-TU Sharing 135
Classic Static TU Isolation 136
Namespace TU Isolation 137
Declaration and Definition 138
TU Definition Conflicts 139
Fine-grained TU Scope Isolation 140
Conceptual Layer (Design) 141
Incomplete Types 142
References 143
Type& vs. Type* 144
Values 145
Value Categories 146
Constant Values 147
Constant Expressions 148
Functions 149
Pointers to Functions 150
Function Pointer Types 152
Reading Declarations 153
Structure Function Fields 154
Structure Methods 155
Structure Methods (Inlined) 156
Structure Methods (Inheritance) 157
Structure Virtual Methods 159
Structure Pure Virtual Methods 161
Structure as Interface 162
Function Structure 163
Structure Constructors 164
Structure Copy Constructor 165
Structure Copy Assignment 166
Structure Destructor 167
Structure Destructor Hierarchy 168
Structure Virtual Destructor 169
Destructor as a Method 170
Conversion Operators 171
Parameters by Value 173
Parameters by Pointer/Reference 174
Parameters by Ptr/Ref to Const 175
Possible Mistake 176
Function Overloading 177
Immutable Objects 178
Static Structure Functions 179
Lambdas 180
x64 CPU Registers 181
x64 Instructions and Registers 182
x64 Memory and Stack Addressing 183
x64 Memory Load Instructions 184
x64 Memory Store Instructions 185
x64 Flow Instructions 186
x64 Function Parameters 187
x64 Struct Function Parameters 188
A64 CPU Registers 189
A64 Instructions and Registers 190
A64 Memory and Stack Addressing 191
A64 Memory Load Instructions 192
A64 Memory Store Instructions 193
A64 Flow Instructions 194
A64 Function Parameters 195
A64 Struct Function Parameters 196
this 197
Function Objects vs. Lambdas 198
A64 Lambda Example 200
Captures and Closures 201
A64 Captures Example 203
Lambdas as Parameters 204
A64 Lambda Parameter Example 206
Lambda Parameter Optimization 207
A64 Optimization Example 209
Lambdas as Unnamed Functions 210
std::function Lambda Parameters 212
auto Lambda Parameters 214
Lambdas as Return Values 216
Virtual Function Call 218
VTBL Memory Layout 219
VPTR and Struct Memory Layout 220
Templates: A Planck-length Introduction 221
Why Templates? 222
Reusability 223
Types of Templates 225
Types of Template Parameters 226
Type Safety 228
Flexibility 230
Metafunctions 231
Iterators as Pointers 232
Containers 233
Iterators 234
Constant Iterators 235
Pointers as Iterators 236
Algorithms 237
Memory Ownership 238
Pointers as Owners 239
Problems with Pointer Owners 240
Smart Pointers 241
Basic Design 242
Unique Pointers 243
Descriptors as Unique Pointers 244
Shared Pointers 245
RAII 246
RAII Definition 247
RAII Advantages 248
File Descriptor RAII 249
Threads and Synchronization 250
Threads in C/C++ 251
Threads in C++ Proper 252
Synchronization Problems 253
Synchronization Solution 254
Resources 255
C and C++ 256
Training (Linux C and C++) 257

Примеры страниц (скриншоты)

Оглавление

Preface vii
1. Basics 1
1.0 Introduction 1
1.1 Installing NGINX on Debian/Ubuntu 1
1.2 Installing NGINX Through the YUM Package Manager 2
1.3 Installing NGINX Plus 3
1.4 Verifying Your Installation 3
1.5 Key Files, Directories, and Commands 4
1.6 Using Includes for Clean Configs 6
1.7 Serving Static Content 7
2. High-Performance Load Balancing 9
2.0 Introduction 9
2.1 HTTP Load Balancing 10
2.2 TCP Load Balancing 11
2.3 UDP Load Balancing 13
2.4 Load-Balancing Methods 14
2.5 Sticky Cookie with NGINX Plus 17
2.6 Sticky Learn with NGINX Plus 18
2.7 Sticky Routing with NGINX Plus 19
2.8 Connection Draining with NGINX Plus 20
2.9 Passive Health Checks 21
2.10 Active Health Checks with NGINX Plus 22
2.11 Slow Start with NGINX Plus 24
3. Traffic Management 25
3.0 Introduction 25
3.1 A/B Testing 25
3.2 Using the GeoIP Module and Database 27
3.3 Restricting Access Based on Country 30
3.4 Finding the Original Client 31
3.5 Limiting Connections 32
3.6 Limiting Rate 34
3.7 Limiting Bandwidth 35
4. Massively Scalable Content Caching 37
4.0 Introduction 37
4.1 Caching Zones 37
4.2 Caching Hash Keys 39
4.3 Cache Locking 40
4.4 Use Stale Cache 40
4.5 Cache Bypass 41
4.6 Cache Purging with NGINX Plus 42
4.7 Cache Slicing 43
5. Programmability and Automation 45
5.0 Introduction 45
5.1 NGINX Plus API 45
5.2 Using the Key-Value Store with NGINX Plus 49
5.3 Using the njs Module to Expose JavaScript Functionality Within NGINX 51
5.4 Extending NGINX with a Common Programming Language 54
5.5 Installing with Ansible 56
5.6 Installing with Chef 58
5.7 Automating Configurations with Consul Templating 59
6. Authentication 63
6.0 Introduction 63
6.1 HTTP Basic Authentication 63
6.2 Authentication Subrequests 65
6.3 Validating JWTs with NGINX Plus 66
6.4 Creating JSON Web Keys 68
6.5 Authenticate Users via Existing OpenID Connect SSO with NGINX Plus 69
6.6 Validate JSON Web Tokens (JWT) with NGINX Plus 70
6.7 Automatically Obtaining and Caching JSON Web Key Sets with NGINX Plus 71
6.8 Configuring NGINX Plus as a Service Provider for SAML Authentication 72
7. Security Controls 77
7.0 Introduction 77
7.1 Access Based on IP Address 77
7.2 Allowing Cross-Origin Resource Sharing 78
7.3 Client-Side Encryption 79
7.4 Advanced Client-Side Encryption 81
7.5 Upstream Encryption 83
7.6 Securing a Location 84
7.7 Generating a Secure Link with a Secret 84
7.8 Securing a Location with an Expire Date 85
7.9 Generating an Expiring Link 86
7.10 HTTPS Redirects 88
7.11 Redirecting to HTTPS Where SSL/TLS Is Terminated Before NGINX 89
7.12 HTTP Strict Transport Security 89
7.13 Restricting Access Based on Country 90
7.14 Satisfying Any Number of Security Methods 92
7.15 NGINX Plus Dynamic Application Layer DDoS Mitigation 92
7.16 Installing and Configuring NGINX Plus with the NGINX App Protect WAF Module 94
8. HTTP/2 and HTTP/3 (QUIC) 99
8.0 Introduction 99
8.1 Enabling HTTP/2 99
8.2 Enabling HTTP/3 100
8.3 gRPC 102
9. Sophisticated Media Streaming 105
9.0 Introduction 105
9.1 Serving MP4 and FLV 105
9.2 Streaming with HLS with NGINX Plus 106
9.3 Streaming with HDS with NGINX Plus 107
9.4 Bandwidth Limits with NGINX Plus 108
10. Cloud Deployments 109
10.0 Introduction 109
10.1 Auto-Provisioning 109
10.2 Deploying an NGINX VM in the Cloud 111
10.3 Creating an NGINX Machine Image 112
10.4 Routing to NGINX Nodes Without a Cloud Native Load Balancer 113
10.5 The Load Balancer Sandwich 115
10.6 Load Balancing over Dynamically Scaling NGINX Servers 117
10.7 Creating a Google App Engine Proxy 118
11. Containers/Microservices 121
11.0 Introduction 121
11.1 Using NGINX as an API Gateway 122
11.2 Using DNS SRV Records with NGINX Plus 126
11.3 Using the Official NGINX Container Image 127
11.4 Creating an NGINX Dockerfile 128
11.5 Building an NGINX Plus Container Image 132
11.6 Using Environment Variables in NGINX 133
11.7 NGINX Ingress Controller from NGINX 134
12. High-Availability Deployment Modes 137
12.0 Introduction 137
12.1 NGINX Plus HA Mode 137
12.2 Load Balancing Load Balancers with DNS 140
12.3 Load Balancing on EC2 141
12.4 NGINX Plus Configuration Synchronization 142
12.5 State Sharing with NGINX Plus and Zone Sync 144
13. Advanced Activity Monitoring 147
13.0 Introduction 147
13.1 Enable NGINX Stub Status 147
13.2 Enabling the NGINX Plus Monitoring Dashboard 148
13.3 Collecting Metrics Using the NGINX Plus API 150
13.4 OpenTelemetry for NGINX 153
13.5 Prometheus Exporter Module 157
14. Debugging and Troubleshooting with Access Logs, Error Logs, and Request Tracing 159
14.0 Introduction 159
14.1 Configuring Access Logs 159
14.2 Configuring Error Logs 161
14.3 Forwarding to Syslog 162
14.4 Debugging Configs 163
14.5 Request Tracing 164
15. Performance Tuning 167
15.0 Introduction 167
15.1 Automating Tests with Load Drivers 167
15.2 Controlling Cache at the Browser 168
15.3 Keeping Connections Open to Clients 169
15.4 Keeping Connections Open Upstream 169
15.5 Buffering Responses 170
15.6 Buffering Access Logs 171
15.7 OS Tuning 172
Index 175

Примеры страниц

Оглавление

About the Author ..........................................................................................ix
About the Technical Reviewer .........................................................................xi
Preface ........................................................................................................xiii
Chapter 1: Memory, Registers, and Simple Arithmetic .........................................1
Memory and Registers Inside an Idealized Computer ..........................................1
Memory and Registers Inside Intel 64-Bit PC .......................................................2
“Arithmetic” Project: Memory Layout and Registers ............................................3
“Arithmetic” Project: A Computer Program ...........................................................5
“Arithmetic” Project: Assigning Numbers to Memory Locations ...........................5
Assigning Numbers to Registers ...........................................................................8
“Arithmetic” Project: Adding Numbers to Memory Cells .......................................8
Incrementing/Decrementing Numbers in Memory and Registers .......................11
Multiplying Numbers ...........................................................................................14
Summary.............................................................................................................17
Chapter 2: Code Optimization .............................................................................19
“Arithmetic” Project: C/C++ Program .................................................................19
Downloading GDB ...............................................................................................20
GDB Disassembly Output – No Optimization .......................................................20
GDB Disassembly Output – Optimization ............................................................25
Summary.............................................................................................................26
Chapter 3: Number Representations.....................................................................27
Numbers and Their Representations ...................................................................27
Decimal Representation (Base Ten) ....................................................................28
Ternary Representation (Base Three) ..................................................................29
Binary Representation (Base Two) ......................................................................29
Hexadecimal Representation (Base Sixteen) ......................................................30
Why Are Hexadecimals Used? .............................................................................30
Summary.............................................................................................................32
Chapter 4: Pointers ...............................................................................................33
A Definition..........................................................................................................33
“Pointers” Project: Memory Layout and Registers ..............................................34
“Pointers” Project: Calculations ..........................................................................36
Using Pointers to Assign Numbers to Memory Cells ...........................................36
Adding Numbers Using Pointers .........................................................................42
Incrementing Numbers Using Pointers ...............................................................45
Multiplying Numbers Using Pointers ...................................................................48
Summary.............................................................................................................51
Chapter 5: Bytes, Words, Double, and Quad Words .................................................53
Using Hexadecimal Numbers ..............................................................................53
Byte Granularity ..................................................................................................53
Bit Granularity .....................................................................................................54
Memory Layout ...................................................................................................55
Summary.............................................................................................................58
Chapter 6: Pointers to Memory ..............................................................................59
Pointers Revisited ...............................................................................................59
Addressing Types ................................................................................................59
Registers Revisited .............................................................................................65
NULL Pointers .....................................................................................................65
Invalid Pointers ...................................................................................................65
Variables As Pointers ..........................................................................................66
Pointer Initialization ............................................................................................67
Initialized and Uninitialized Data .........................................................................67
More Pseudo Notation .........................................................................................68
“MemoryPointers” Project: Memory Layout..............................................................68
Summary.............................................................................................................79
Chapter 7: Logical Instructions and RIP ..................................................................81
Instruction Format...............................................................................................81
Logical Shift Instructions ....................................................................................82
Logical Operations ..............................................................................................82
Zeroing Memory or Registers.................................................................................83
Instruction Pointer ...............................................................................................84
Code Section .......................................................................................................85
Summary.............................................................................................................86
Chapter 8: Reconstructing a Program with Pointers .................................................87
Example of Disassembly Output: No Optimization ..............................................87
Reconstructing C/C++ Code: Part 1 ....................................................................90
Reconstructing C/C++ Code: Part 2 ....................................................................92
Reconstructing C/C++ Code: Part 3 ....................................................................93
Reconstructing C/C++ Code: C/C++ Program ....................................................94
Example of Disassembly Output: Optimized Program .........................................95
Summary.............................................................................................................96
Chapter 9: Memory and Stacks ............................................................................97
Stack: A Definition ...............................................................................................97
Stack Implementation in Memory .......................................................................98
Things to Remember .........................................................................................100
PUSH Instruction ...............................................................................................101
POP Instruction .................................................................................................101
Register Review ................................................................................................102
Application Memory Simplified .............................................................................105
Stack Overflow ..................................................................................................105
Jumps ...............................................................................................................106
Calls ..................................................................................................................108
Call Stack ..........................................................................................................110
Exploring Stack in GDB .....................................................................................112
Summary...........................................................................................................115
Chapter 10: Frame Pointer and Local Variables .......................................................117
Stack Usage ......................................................................................................117
Register Review ................................................................................................118
Addressing Array Elements ...............................................................................118
Stack Structure (No Function Parameters) ...........................................................119
Function Prolog .................................................................................................121
Raw Stack (No Local Variables and Function Parameters) ........................................121
Function Epilog .................................................................................................123
“Local Variables” Project ..................................................................................124
Disassembly of Optimized Executable ..............................................................127
Summary...........................................................................................................128
Chapter 11: Function Parameters .......................................................................129
“FunctionParameters” Project ..........................................................................129
Stack Structure .................................................................................................130
Function Prolog and Epilog ...............................................................................132
Project Disassembled Code with Comments ....................................................133
Parameter Mismatch Problem ..........................................................................137
Summary...........................................................................................................138
Chapter 12: More Instructions .............................................................................139
CPU Flags Register ............................................................................................139
The Fast Way to Fill Memory .............................................................................140
Testing for 0 ......................................................................................................141
TEST – Logical Compare ...................................................................................142
CMP – Compare Two Operands .........................................................................143
TEST or CMP? ...................................................................................................144
Conditional Jumps ............................................................................................144
The Structure of Registers ................................................................................145
Function Return Value .......................................................................................146
Using Byte Registers .........................................................................................146
Summary...........................................................................................................147
Chapter 13: Function Pointer Parameters ..............................................................149
“FunctionPointerParameters” Project ...................................................................149
Commented Disassembly .................................................................................150
Summary...........................................................................................................159
Chapter 14: S ummary of Code Disassembly Patterns ...........................................161
Function Prolog/Epilog ......................................................................................161
LEA (Load Effective Address) ............................................................................164
Passing Parameters ..........................................................................................164
Accessing Parameters and Local Variables ............................................................165
Summary...........................................................................................................166
Index .............................................................................................................167

Примеры страниц

Оглавление

About the Author ...........................................................................................ix
About the Technical Reviewer ..........................................................................xi
Preface ........................................................................................................xiii
Chapter 1: Memory, Registers, and Simple Arithmetic .........................................1
Memory and Registers Inside an Idealized Computer ..........................................1
Memory and Registers Inside ARM 64-Bit Computer ............................................2
“Arithmetic” Project: Memory Layout and Registers ............................................3
“Arithmetic” Project: A Computer Program ...........................................................5
“Arithmetic” Project: Assigning Numbers to Memory Locations ..............................5
Assigning Numbers to Registers ...........................................................................8
“Arithmetic” Project: Adding Numbers to Memory Cells .......................................9
Incrementing/Decrementing Numbers in Memory and Registers ............................12
Multiplying Numbers ...........................................................................................15
Summary.............................................................................................................18
Chapter 2: Code Optimization .............................................................................19
“Arithmetic” Project: C/C++ Program .................................................................19
Downloading GDB ...............................................................................................20
GDB Disassembly Output – No Optimization .......................................................21
GDB Disassembly Output – Optimization ............................................................27
Summary.............................................................................................................28
Chapter 3: Number Representations....................................................................29
Numbers and Their Representations ...................................................................29
Decimal Representation (Base Ten) ....................................................................30
Ternary Representation (Base Three) ..................................................................30
Binary Representation (Base Two) ......................................................................31
Hexadecimal Representation (Base Sixteen) ......................................................32
Why Are Hexadecimals Used? .............................................................................32
Summary.............................................................................................................34
Chapter 4: Pointers ..............................................................................................35
A Definition..........................................................................................................35
“Pointers” Project: Memory Layout and Registers ..............................................36
“Pointers” Project: Calculations ..........................................................................38
Using Pointers to Assign Numbers to Memory Cells ...........................................39
Adding Numbers Using Pointers .........................................................................46
Incrementing Numbers Using Pointers ...............................................................51
Multiplying Numbers Using Pointers ...................................................................54
Summary.............................................................................................................58
Chapter 5: Bytes, Halfwords, Words, and Doublewords ...........................................59
Using Hexadecimal Numbers ..............................................................................59
Byte Granularity ..................................................................................................60
Bit Granularity .....................................................................................................60
Memory Layout ...................................................................................................61
Summary.............................................................................................................64
Chapter 6: Pointers to Memory .............................................................................65
Pointers Revisited ...............................................................................................65
Addressing Types ................................................................................................65
Registers Revisited .............................................................................................70
NULL Pointers .....................................................................................................70
Invalid Pointers ...................................................................................................70
Variables As Pointers ..........................................................................................71
Pointer Initialization ............................................................................................71
Initialized and Uninitialized Data .........................................................................72
More Pseudo Notation .........................................................................................72
“MemoryPointers” Project: Memory Layout..............................................................73
Summary.............................................................................................................87
Chapter 7: Logical Instructions and PC ...................................................................89
Instruction Format...............................................................................................89
Logical Shift Instructions ....................................................................................90
Logical Operations ..............................................................................................90
Zeroing Memory or Registers.................................................................................91
Program Counter .................................................................................................92
Code Section .......................................................................................................93
Summary.............................................................................................................94
Chapter 8: Reconstructing a Program with Pointers .................................................95
Example of Disassembly Output: No Optimization .................................................95
Reconstructing C/C++ Code: Part 1 ....................................................................98
Reconstructing C/C++ Code: Part 2 ..................................................................100
Reconstructing C/C++ Code: Part 3 ..................................................................102
Reconstructing C/C++ Code: C/C++ Program ......................................................103
Example of Disassembly Output: Optimized Program .............................................104
Summary...........................................................................................................106
Chapter 9: Memory and Stacks ............................................................................107
Stack: A Definition .............................................................................................107
Stack Implementation in Memory ........................................................................108
Things to Remember .........................................................................................110
Stack Push Implementation ..............................................................................111
Stack Pop Implementation ................................................................................111
Register Review ................................................................................................111
Application Memory Simplified .........................................................................112
Stack Overflow ..................................................................................................113
Jumps ...............................................................................................................114
Calls ..................................................................................................................115
Call Stack ..........................................................................................................116
Exploring Stack in GDB .....................................................................................118
Summary...........................................................................................................121
Chapter 10: Frame Pointer and Local Variables ......................................................123
Stack Usage ......................................................................................................123
Register Review ................................................................................................124
Addressing Array Elements ...............................................................................124
Stack Structure (No Function Parameters) .......................................................126
Function Prolog .................................................................................................127
Raw Stack (No Local Variables and Function Parameters) ........................................127
Function Epilog .................................................................................................129
“Local Variables” Project ..................................................................................130
Disassembly of Optimized Executable ..............................................................133
Summary...........................................................................................................134
Chapter 11: Function Parameters ........................................................................135
“FunctionParameters” Project ..........................................................................135
Stack Structure .................................................................................................136
Function Prolog and Epilog ...............................................................................138
Project Disassembled Code with Comments ....................................................139
Parameter Mismatch Problem ..........................................................................144
Summary...........................................................................................................145
Chapter 12: More Instructions .............................................................................147
PSTATE Flags .....................................................................................................147
Testing for 0 ......................................................................................................147
TST – Logical Compare .....................................................................................148
CMP – Compare Two Operands .........................................................................149
TST or CMP? .....................................................................................................150
Conditional Jumps ............................................................................................150
Function Return Value .......................................................................................151
Summary...........................................................................................................152
Chapter 13: Function Pointer Parameters ...........................................................153
“FunctionPointerParameters” Project ...............................................................153
Commented Disassembly .................................................................................154
Summary...........................................................................................................161
Chapter 14: S ummary of Code Disassembly Patterns ............................................163
Function Prolog/Epilog ......................................................................................163
ADR (Address) ...................................................................................................164
Passing Parameters ..........................................................................................164
Accessing Saved Parameters and Local Variables ..................................................165
Summary...........................................................................................................166
Index .............................................................................................................167

Примеры страниц

Оглавление

Acknowledgments ......................................................... xix
Preface ........................................................................ xxi
Introduction ................................................................. xxix
RHCSA Exam Readiness Checklist .................................... xxxii
1 Prepare for the Red Hat RHCSA Certification .. . . . . . . . . 1
The RHCSA Exam .......................................................... 4
The Exam Experience .................................................... 4
Evolving Requirements .................................................. 5
Basic Hardware Requirements ........................................ 5
Hardware Compatibility ................................................. 6
Architectures ............................................................... 6
RAM Requirements ....................................................... 7
Storage Options ............................................................ 7
Networking ................................................................. 8
Virtual Machine Options ................................................ 8
Get Red Hat Enterprise Linux .......................................... 9
Get a Subscription at No Cost .......................................... 10
Purchase a Subscription .................................................. 10
Third-Party Rebuilds ..................................................... 10
Check the Download ..................................................... 11
Exercise 1-1: Get Red Hat Enterprise Linux ...................... 12
An Environment for Practice Labs .................................... 12
System Roles ................................................................ 14
Getting VMware Workstation Player .................................. 14
Virtual Networks on a Hypervisor ..................................... 16
Configure a Virtual Machine on VMware Workstation Player .... 18
RHEL 9 Installation .......................................................... 22
Boot Media ..................................................................... 22
Basic Installation Steps ................................................... 24
The Installation Perspective on Partitions ............................ 27
Partition Creation Exercise .............................................. 30
Exercise 1-2: Partitioning During Installation .................... 32
Wow, Look at All That Software! ....................................... 34
Baseline Packages ......................................................... 35
During the Installation ................................................... 35
x RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Initial Setup ................................................................. 36
Certification Summary ................................................... 37
✓ Two-Minute Drill .......................................................... 38
Q&A Self Test ................................................................ 39
Lab Questions .............................................................. 40
Self Test Answers .......................................................... 41
Lab Answers ................................................................ 42
2 Fundamental Command-Line Skills .. . . . . . . . . . . . . . . 43
Shells ......................................................................... 46
Other Shells ................................................................ 46
Virtual Consoles ........................................................... 47
GUI Shell Interfaces ...................................................... 47
Differences Between Regular and Administrative Users .......... 49
Standard Streams and Command Redirection ...................... 49
Standard Command-Line Tools ......................................... 51
File and Directory Concepts ............................................ 52
File Lists and ls ............................................................. 54
File-Creation Commands ................................................ 55
Wildcards ................................................................... 58
File Searches ................................................................ 59
File Permissions ............................................................ 60
File Permissions and Ownership ....................................... 60
Commands to Change Permissions and Ownership ............... 63
A Basic Introduction of User and Group Concepts ................ 66
Managing Text Files ......................................................... 68
Commands to Read Text Streams ...................................... 68
Commands to Process Text Streams ................................... 70
Edit Text Files at the Console ........................................... 73
Exercise 2-1: Using vi to Create a New User ...................... 75
If You Don’t Like vi ........................................................ 77
Edit Text Files in the GUI ................................................ 78
Accessing the Documentation ......................................... 78
When You Need Help .................................................... 79
A Variety of man Pages ................................................... 80
The info Manuals .......................................................... 81
Detailed Documentation in /usr/share/doc .......................... 81
Certification Summary ................................................... 82
✓ Two-Minute Drill .......................................................... 83
Q&A Self Test ................................................................ 85
Lab Questions .............................................................. 86
Self Test Answers .......................................................... 86
Lab Answers ................................................................ 87
3 Managing Basic Networking .. . . . . . . . . . . . . . . . . . . . 91
A Networking Primer ..................................................... 93
IPv4 Networks ............................................................. 93
Networks and Routing ................................................... 94
Tools and Commands .................................................... 95
Network Configuration and Troubleshooting ..................... 101
Network Configuration Services ....................................... 101
Network Configuration Tools ........................................... 103
Exercise 3-1: Configure IPv4 Settings on a Network Interface 105
Configure Name Resolution ............................................. 109
Hostname Configuration Files .......................................... 109
An Introduction to IPv6 .................................................. 111
Basic IPv6 Addressing .................................................... 111
Troubleshooting Tools ................................................... 113
Configure IPv6 Addresses ............................................... 114
Administration with Secure Shell and Secure Copy ............. 115
Command-Line Access ................................................... 116
More SSH Command-Line Tools ...................................... 117
Graphical Secure Shell Access .......................................... 117
Certification Summary ................................................... 119
✓ Two-Minute Drill .......................................................... 119
Q&A Self Test ............................................................... 120
Lab Questions .............................................................. 121
Self Test Answers .......................................................... 122
Lab Answers ................................................................ 123
4 Software Management . . . . . . . . . . . . . . . . . . . . . . . . 127
The RPM Package Manager .............................................. 129
What Is a Package? ........................................................ 129
What Is the RPM Database? ............................................. 130
What Is a Repository? .................................................... 130
Install an RPM Package .................................................. 131
Uninstall an RPM Package ............................................... 133
Install RPMs from Remote Systems ................................... 133
RPM Installation Security ............................................... 134
Updating the Kernel ...................................................... 134
More RPM Commands .................................................... 136
Package Queries ........................................................... 137
Package Signatures ........................................................ 137
File Verification ............................................................ 138
Exercise 4-1: Practice with rpm Commands ...................... 140
xii RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Dependencies and the dnf Command ............................... 141
An Example of Dependency Hell ....................................... 142
Relief from Dependency Hell ........................................... 143
Red Hat Subscription Management ................................... 144
Exercise 4-2: Subscribe a System to Red Hat
Subscription Management ............................................... 145
Basic dnf Configuration .................................................. 148
Exercise 4-3: Create a dnf Repository from the RHEL 9 DVD 152
Third-Party Repositories ................................................. 154
Exercise 4-4: Configure Access to the EPEL Repository ........ 154
Basic dnf Commands ..................................................... 155
Installation Mode .......................................................... 155
Security and dnf ........................................................... 157
Updates and Security Fixes .............................................. 157
Package Groups and dnf ................................................. 157
More dnf Commands ..................................................... 160
Module Streams (*) ...................................................... 162
Certification Summary ................................................... 165
✓ Two-Minute Drill .......................................................... 165
Q&A Self Test ............................................................... 167
Lab Questions .............................................................. 168
Self Test Answers .......................................................... 168
Lab Answers ................................................................ 169
5 systemd and the Boot Process .. . . . . . . . . . . . . . . . . . . 173
The Boot Process ........................................................... 175
Basic System Configuration ............................................. 175
Startup Menus ............................................................. 176
Access to Linux Bootloaders ............................................ 176
Bootloaders and GRUB 2 ................................................ 177
GRUB, the GRand Unified Bootloader ................................ 178
Exercise 5-1: Boot into a Different Target ......................... 180
Exercise 5-2: Recover the Root Password .......................... 181
Modify the System Bootloader ......................................... 182
How to Update GRUB 2 .................................................. 184
The GRUB 2 Command Line ........................................... 185
Exercise 5-3: Using the GRUB 2 Command Line ................ 186
An Option for Booting from GRUB 2: Rescue Mode ............... 187
Between GRUB 2 and Login .............................................. 189
Kernels and the Initial RAM Disk ...................................... 190
The First Process, Targets, and Units .................................. 191
Switch Between Targets .................................................. 193
Reboot and Shut Down a System Normally .......................... 193
systemd Replaces Upstart and SysVinit ............................... 194
systemd Units .............................................................. 197
Virtual Consoles and Login Screens ................................... 199
Control by Target ........................................................... 200
Functionality by Target ................................................... 200
The Innards of systemd Units ........................................... 201
Service Configuration .................................................... 203
Time Synchronization .................................................... 204
Time Zone Configuration ................................................ 205
Sync the Time with chronyd ............................................ 206
Certification Summary ................................................... 207
✓ Two-Minute Drill .......................................................... 207
Q&A Self Test ................................................................ 209
Lab Questions .............................................................. 210
Self Test Answers .......................................................... 210
Lab Answers ................................................................ 211
6 User Administration .. . . . . . . . . . . . . . . . . . . . . . . . . . 215
User Account Management ............................................. 216
Different Kinds of Users ................................................. 217
The Shadow Password Suite ............................................ 218
Command-Line Tools .................................................... 225
Exercise 6-1: Add a User with Cockpit Web Console ........... 228
Exercise 6-2: Real and Fake Shells ................................... 230
Modify an Account ........................................................ 230
Administrative Control ................................................... 232
The Ability to Log In ...................................................... 232
The su Command ......................................................... 233
Limit Access to su ......................................................... 234
The sg Command .......................................................... 234
Superuser Access with the sudo Command ........................ 234
User and Shell Configuration ............................................. 236
Home Directories and /etc/skel ........................................ 236
Exercise 6-3: Another Way to Secure a System ................... 238
Shell Configuration Files in User Home Directories ............... 239
Login, Logout, and User Switching .................................... 239
Special Groups .............................................................. 240
Standard and Red Hat Groups .......................................... 241
Shared Directories ........................................................ 241
Exercise 6-4: Control Group Ownership with the SGID Bit .... 242
Certification Summary ................................................... 244
✓ Two-Minute Drill .......................................................... 244
xiv RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
Q&A Self Test ................................................................ 245
Lab Questions .............................................................. 246
Self Test Answers .......................................................... 246
Lab Answers ................................................................ 247
7 Storage and Filesystem Administration .. . . . . . . . . . . . . 253
Storage Management and Partitions ................................. 255
Current System State ..................................................... 255
The fdisk Utility ............................................................ 257
The gdisk Utility ........................................................... 264
The parted Utility ......................................................... 265
Using parted: Starting, Getting Help, and Quitting ............ 266
Graphical Options ......................................................... 271
Exercise 7-1: Work with fdisk and parted .......................... 272
Filesystem Formats ........................................................ 274
Standard Filesystems ...................................................... 275
Journaling Filesystems .................................................... 276
Filesystem Format Commands ......................................... 276
Swap Volumes .............................................................. 277
Filesystem Check Commands ........................................... 278
Exercise 7-2: Format, Check, and
Mount Different Filesystems ............................................. 278
Basic Linux Filesystems and Directories ............................. 279
Separate Linux Filesystems .............................................. 279
Directories That Can Be Mounted Separately ....................... 281
Logical Volume Manager (LVM) ......................................... 282
Definitions in LVM .......................................................... 282
Create a Physical Volume ................................................ 283
Create a Volume Group .................................................. 283
Create a Logical Volume ................................................. 283
Make Use of a Logical Volume .......................................... 284
More LVM Commands ................................................... 284
Remove a Logical Volume ............................................... 287
Resize Logical Volumes .................................................. 287
Filesystem Management ................................................. 288
The /etc/fstab File ......................................................... 288
Universally Unique Identifiers in /etc/fstab ........................ 290
The mount Command .................................................... 291
More Filesystem Mount Options ....................................... 292
Virtual Filesystems ........................................................ 293
Add Your Own Filesystems to /etc/fstab .............................. 293
Removable Media and /etc/fstab ....................................... 293
Network Filesystems ...................................................... 294
The Automounter ........................................................... 296
Mounting via the Automounter ........................................ 296
Exercise 7-3: Configure the Automounter ......................... 300
Certification Summary ................................................... 301
✓ Two-Minute Drill .......................................................... 302
Q&A Self Test ................................................................ 303
Lab Questions .............................................................. 304
Self Test Answers .......................................................... 305
Lab Answers ................................................................ 306
8 Linux Security .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311
Basic Firewall Control .................................................... 313
Standard Ports ............................................................. 314
The firewalld Service ..................................................... 315
Exercise 8-1: Adjust Firewall Settings .............................. 320
Exercise 8-2: Firewall Configuration
with the Cockpit Web Console ......................................... 322
Securing SSH with Key-Based Authentication .................... 324
SSH Configuration Commands ......................................... 324
SSH Client Configuration Files ......................................... 325
Basic Encrypted Communication ...................................... 325
Set Up a Private/Public Pair for Key-Based Authentication ... 327
A Security-Enhanced Linux Primer .................................... 329
Basic Features of SELinux ............................................... 329
SELinux Status ............................................................. 329
SELinux Configuration at the Command Line ...................... 331
Configure Basic SELinux Settings ...................................... 331
Configure Regular Users for SELinux ................................. 332
Manage SELinux Boolean Settings ..................................... 334
List and Identify SELinux File Contexts .............................. 334
Restore SELinux File Contexts .......................................... 336
Exercise 8-3: Configure a New Directory
with Appropriate SELinux Contexts ................................... 337
SELinux Port Labeling .................................................... 338
Identify SELinux Process Contexts .................................... 338
Diagnose and Address SELinux Policy Violations .................. 339
The GUI SELinux Administration Tool ............................... 341
Certification Summary ................................................... 344
✓ Two-Minute Drill .......................................................... 345
Q&A Self Test ............................................................... 346
Lab Questions .............................................................. 346
Self Test Answers .......................................................... 347
Lab Answers ................................................................ 348
xvi RHCSA Red Hat Enterprise Linux 9 Certification Study Guide
9 System Administration Tasks . . . . . . . . . . . . . . . . . . . . . . 353
Resource Management and System Tuning ........................... 355
System Resource Management Commands .......................... 355
System Tuning Profiles ................................................... 365
Archives and Compression .............................................. 367
gzip and bzip2 .............................................................. 367
tar ............................................................................. 368
star ........................................................................... 368
Running Tasks on a Schedule: cron and at ...................... 369
The System crontab and Components ................................ 369
Hourly cron Jobs ........................................................... 372
Regular anacron Jobs ..................................................... 372
Setting Up cron for Users ................................................ 373
Exercise 9-1: Create a cron Job ...................................... 374
Running a Job with the at System ...................................... 374
Secure cron and at ........................................................ 375
Bash Scripts ................................................................. 377
A “Hello, World” Script .................................................. 377
Bash Variables .............................................................. 378
Bash Control Structures ................................................. 381
Exercise 9-2: Create a Script ......................................... 386
Local Log Files ............................................................... 388
System Log Configuration File .......................................... 389
Log File Management ..................................................... 390
A Variety of Log Files ..................................................... 391
Service-Specific Logs ..................................................... 392
Exercise 9-3: Learn the Log Files .................................... 392
View systemd Journal Log Entries ..................................... 392
Certification Summary ................................................... 395
✓ Two-Minute Drill .......................................................... 396
Q&A Self Test ................................................................ 397
Lab Questions .............................................................. 399
Self Test Answers .......................................................... 399
Lab Answers ................................................................ 400
10 An Introduction to Containers .. . . . . . . . . . . . . . . . . . 405
Fundamentals of Container Technology .............................. 407
The Rise of Container Technologies ................................... 407
Virtualization and Containers .......................................... 409
Understanding Container Architecture ............................... 410
Docker and Podman ...................................................... 411
Getting Started with Containers ....................................... 412
Installing Container Tools ............................................... 412
Running Your First Container ........................................... 413
Rootless and Rootful Containers ....................................... 415
Building and Using Container Images .............................. 416
Image Registries ........................................................... 416
Building Container Images: A Primer ................................. 418
Exercise 10-1: Building and Running a Container Image ....... 420
Exercise 10-2: Uploading an Image to Quay.io ................... 421
Managing Containers ..................................................... 422
Podman Commands ...................................................... 422
Running a Container as a SystemD Service ........................ 430
Exercise 10-3: Running a Container as a Service ................. 432
Persistent Storage ......................................................... 434
Exercise 10-4: Attaching Persistent Storage to a Container ... 435
Certification Summary ................................................... 436
✓ Two-Minute Drill .......................................................... 437
Q&A Self Test ................................................................ 438
Lab Questions .............................................................. 439
Self Test Answers .......................................................... 440
Lab Answers ................................................................ 442
A Prepare a System for the Sample Exams .. . . . . . . . . . . 447
Sample Exam System Requirements ............................... 447
B Solutions to RHCSA Sample Exam 1 . . . . . . . . . . . . . . . 451
RHCSA Sample Exam 1 Discussion .................................. 453
C Solutions to RHCSA Sample Exam 2 . . . . . . . . . . . . . . . 459
RHCSA Sample Exam 2 Discussion .................................. 461
D About the Online Content .. . . . . . . . . . . . . . . . . . . . . . 467
Single User License Terms and Conditions ........................ 467
Downloadable Book Resources ....................................... 469
Lab Files ..................................................................... 469
Appendix A: Prepare a System for the Sample Exams ....... 469
Sample Exams ............................................................ 469
Technical Support ........................................................ 469
Index .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471

Примеры страниц

Примеры страниц

Оглавление

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xvii
Chapter 1: Digital Forensics Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Chapter 2: Linux Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Chapter 3: Evidence from Storage Devices and Filesystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Chapter 4: Directory Layout and Forensic Analysis of Linux Files . . . . . . . . . . . . . . . . . . . . . . . . . 83
Chapter 5: Investigating Evidence from Linux Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
Chapter 6: Reconstructing System Boot and Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Chapter 7: Examination of Installed Software Packages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183
Chapter 8: Identifying Network Configuration Artifacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Chapter 9: Forensic Analysis of Time and Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
Chapter 10: Reconstructing User Desktops and Login Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . 273
Chapter 11: Forensic Traces of Attached Peripheral Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Afterword. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
Appendix: File/Directory List for Digital Investigators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361

Примеры страниц

Оглавление

Introduction xxx
Part I Performing Basic System Management Tasks
CHAPTER 1 Installing Red Hat Enterprise Linux 3
CHAPTER 2 Using Essential Tools 27
CHAPTER 3 Essential File Management Tools 53
CHAPTER 4 Working with Text Files 81
CHAPTER 5 Connecting to Red Hat Enterprise Linux 9 101
CHAPTER 6 User and Group Management 121
CHAPTER 7 Permissions Management 145
CHAPTER 8 Configuring Networking 167
Part II Operating Running Systems
CHAPTER 9 Managing Software 195
CHAPTER 10 Managing Processes 231
CHAPTER 11 Working with Systemd 253
CHAPTER 12 Scheduling Tasks 271
CHAPTER 13 Configuring Logging 287
CHAPTER 14 Managing Storage 311
CHAPTER 15 Managing Advanced Storage 343
Part III Performing Advanced System Administration Tasks
CHAPTER 16 Basic Kernel Management 369
CHAPTER 17 Managing and Understanding the Boot Procedure 387
CHAPTER 18 Essential Troubleshooting Skills 403
CHAPTER 19 An Introduction to Automation with Bash Shell Scripting 421
Part IV Managing Network Services
CHAPTER 20 Configuring SSH 439
CHAPTER 21 Managing Apache HTTP Services 453
CHAPTER 22 Managing SELinux 469
CHAPTER 23 Configuring a Firewall 495
CHAPTER 24 Accessing Network Storage 509
CHAPTER 25 Configuring Time Services 523
CHAPTER 26 Managing Containers 539
CHAPTER 27 Final Preparation 573
CHAPTER 28 Theoretical Pre-Assessment Exam 579
Part V RHCSA 9 Practice Exams
RHCSA Practice Exam A 581
RHCSA Practice Exam B 583
APPENDIX A: Answers to the “Do I Know This Already?”
Quizzes and Review Questions 585
APPENDIX B: Red Hat RHCSA 9 Cert Guide: EX200 Exam Updates 617
Glossary 619
Index 641
Online Elements
RHCSA Practice Exam C
RHCSA Practice Exam D
APPENDIX C: Memory Tables
APPENDIX D: Memory Tables Answer Key
APPENDIX E: Study Planner
Glossary

Примеры страниц

Оглавление

Preface xiii
Part 1: Server Installations and
Management Commands
1
Getting a CentOS
Server Up and Running 3
Downloading the OS installation
file 4
Downloading and setting up a
hypervisor 7
Package installation commands 28
YUM package management system 28
Common package installation
commands 29
Information commands 30
Summary 32
2
Linux User and Group Commands 33
useradd, userdel, and usermod 34
useradd 34
userdel 36
usermod 38
Files, directories, and permission
commands 40
chmod 41
chown 41
chgrp 41
groupdel, groupmod, groupadd,
and grpck 42
pwck, chage, and passwd
commands 44
find, locate, and whereis
commands 48
Summary 50
3
File Compression and Archival Commands 51
gunzip and gzip 52
tar, rar, and unrar 55
zip and unzip 57
bunzip2, bzip2, and more 58
Summary 63
Part 2: Frequently Used Commands - Part 1
4
Format and Disk Space Commands 67
The history and evolution of disk
formatting and partitioning in
Linux 68
Steps to create a partition 69
fdisk, lsblk, df, and du 73
Checking the disk space usage of a
directory 75
Finding large files in a directory 76
Displaying (dpkg and rpm)
package space 76
Installing a package 77
Querying the details of a package 77
mkfs, mke2fs, fdformat, and
more 78
Summary 84
5
Linux Permissions Commands 87
Why permission commands? 88
Types of permissions 89
chmod 90
chown 94
Utilizing absolute paths in
commands 96
chgrp 98
umask 99
sudo 101
Summary 103
6
Filesystem Mount and Manipulation Commands 105
Linux mount commands 106
The mount command 106
The umount command 109
The fuser command 111
File manipulation using cat,
grep, and more 114
Summary 117
Part 3: Frequently Used Commands - Part 2
7
File Content and Conversion Commands 121
The tail and file commands 122
The convert command 124
Using dos2unix to convert MS-DOS
files to Unix 127
Using unix2dos to convert Unix
files to MS-DOS 129
The recode command 131
Summary 132
8
Linux SWAP Commands 133
The swapon command 134
The free command 136
Summary 138
9
Linux Monitoring and Debugging Commands 139
The top command 140
The ps command 143
The pstree command 145
The strace command 146
The watch command 148
The smartctl command 148
The uptime command 149
The lsof command 150
The lsmod command 151
The last reboot command 153
The last command 153
The w command 154
The vmstat command 154
The kill command 156
The pkill command 157
Summary 158
10
Linux IPTABLES and Network Commands 159
iptables -t ACCEPT 160
iptables -t DROP 162
ifconfig, ip, route, and netstat 163
ip, route, and netstat 163
Hostname and nslookup 165
host 167
Summary 168
11
File Transfer, Downloading, and Managing Log Files 169
Copying files into remote systems
using netcat and socat 170
Downloading files with wget and curl 173
Exploring common log files 175
Summary 178
Part 4: Linux Security and the Cloud
12
Exploring Linux Security 181
Utilizing enforcing and permissive
modes 182
A short introduction to Linux hardening and
the role of SELinux’s enforcing and passive
modes 183
The role of enforcing mode 183
The role of permissive mode 183
Enabling or disabling SELinux
Boolean values 184
Searching for a Boolean and getting its
information 186
Enabling a SELinux Boolean value 187
Disabling a SELinux Boolean value 187
Locking user accounts 188
Securing SSH 189
Summary 192
13
Linux in the Cloud 193
Creating EC2 instances on AWS 194
Connecting to a created EC2
instance using PuTTY 207
Working on our EC2 instance 212
Summary 218
Index 219
Other Books You May Enjoy 228

Примеры страниц

Оглавление

Предисловие...............................................................................................................29
Вступление.................................................................................................................30
Глава 1. Введение.......................................................................................................44
Глава 2. Основы технологии.........................................................................................60
Глава 3. Анализ производительности.............................................................................117
Глава 4. BCC................................................................................................................137
Глава 5. bpftrace..........................................................................................................182
Глава 6. Процессоры....................................................................................................236
Глава 7. Память...........................................................................................................301
Глава 8. Файловые системы..........................................................................................337
Глава 9. Дисковый ввод/вывод.....................................................................................406
Глава 10. Сети.............................................................................................................455
Глава 11. Безопасность................................................................................................556
Глава 12. Языки..........................................................................................................584
Глава 13. Приложения.................................................................................................658
Глава 14. Ядро............................................................................................................702
Глава 15. Контейнеры..................................................................................................738
Глава 16. Гипервизоры................................................................................................756
Глава 17. Другие инструменты BPF для анализа производительности..............................775
Глава 18. Советы, рекомендации и типичные проблемы.................................................795
Приложение A. Однострочные сценарии для bpftrace.....................................................811
Приложение B. Шпаргалка по bpftrace..........................................................................816
Приложение C. Разработка инструментов BCC...............................................................819
Приложение D. C BPF...................................................................................................833
Приложение E. Инструкции BPF....................................................................................852
Глоссарий..................................................................................................................858
Библиография............................................................................................................868

Примеры страниц

Оглавление

Введение .................................................................................................................. 1
История создания GNU/Linux ................................................................................... 1
Что означает свобода распространения программного обеспечения? ............... 4
Сертификация LPI ................................................................................................... 4
Для кого предназначена книга? ............................................................................. 5
Благодарности ......................................................................................................... 7
ЧАСТЬ I. НАЧАЛО РАБОТЫ В GNU/LINUX .................................................................. 9
Глава 1. Первый раз устанавливаем GNU/Linux .................................................... 11
Предварительные требования для установки GNU/Linux...................................... 11
Установка GNU/Linux .............................................................................................. 12
Глава 2. Работа в оболочке Bash .......................................................................... 25
Учетные записи и вход в сеанс ............................................................................. 25
Как вводить команды в shell?................................................................................. 28
Смена пароля пользователя .................................................................................. 29
Идентификация пользователя .............................................................................. 30
Кто сейчас работает в системе? ........................................................................... 31
Что такое оболочка? ............................................................................................. 32
Структура командной строки ................................................................................ 32
Популярные оболочки GNU/Linux .......................................................................... 35
Встроенные и системные команды ........................................................................ 36
Редактирование и исполнение команд ................................................................ 37
Переменные оболочки и окружения .................................................................... 38
История команд ..................................................................................................... 41
Автоматическое дополнение командной строки ................................................. 43
Псевдонимы команд (aliases) ................................................................................ 44
Командная подстановка ........................................................................................ 45
Вычисление арифметических выражений ........................................................... 47
Шаблоны подстановки и перечисление ............................................................... 48
Глава 3. Помощь и документация ......................................................................... 51
Сообщения об ошибках ........................................................................................ 51
Встроенная помощь оболочки Bash ..................................................................... 52
Страницы помощи man ......................................................................................... 52
Файлы страниц man .............................................................................................. 55
GNU Texinfo ............................................................................................................ 57
Документация программ ....................................................................................... 58
Источники информации в Интернете .................................................................. 59
ЧАСТЬ II. ОСНОВЫ .................................................................................................. 61
Глава 4. Работа с файлами и каталогами ............................................................. 63
Система файлов и каталогов ................................................................................ 63
Имена файлов и команда ls .................................................................................. 65
Перемещение по файловой системе .................................................................... 68
Создание и удаление файлов и каталогов ........................................................... 68
Копирование, перемещение и переименование файлов .................................... 72
Поиск файлов ......................................................................................................... 74
Быстрый поиск файлов locate ................................................................................ 76
Определение содержимого файла ....................................................................... 77
Устройство файловой системы .............................................................................. 78
Использование жестких связей ............................................................................ 80
Использование символических ссылок .................................................................. 84
Глава 5. Процессы ................................................................................................. 87
Процессы и задания .............................................................................................. 87
Фоновый режим выполнения заданий .................................................................. 91
Жизненный цикл процесса ................................................................................... 93
Мониторинг процессов ......................................................................................... 95
Сигналы ................................................................................................................ 101
Перехват и обработка сигналов в Bash ............................................................. 103
Управление приоритетом процессов ................................................................. 104
Глава 6. Права доступа и права владения .......................................................... 107
Права владения файлами ..................................................................................... 107
Права доступа, устанавливаемые на файлы ....................................................... 108
Права доступа к каталогам ................................................................................. 110
Изменение прав владения ................................................................................... 111
Установка прав доступа ...................................................................................... 114
Автоматическая установка прав доступа к вновь создаваемым файлам .......... 118
Специальные биты прав доступа: SUID, SGID и sticky bit .................................. 119
ЧАСТЬ III. УТИЛИТЫ КОМАНДНОЙ СТРОКИ ......................................................... 125
Глава 7. Редактор vi ........................................................................................... 127
Запуск vi и режимы его работы.......................................................................... 127
Перемещение курсора по тексту в vi ................................................................. 129
Команды vi редактирования текста ................................................................... 131
Команды поиска и замены строк ........................................................................ 132
Команды режима двоеточия ............................................................................... 135
Глава 8. Текстовые файлы и потоки ................................................................... 138
Перенаправление потоков ввода/вывода .......................................................... 138
Конвейеры и фильтры ......................................................................................... 142
Команда echo ....................................................................................................... 144
Просмотр файлов с помощью more и less .......................................................... 145
Объединение файлов с помощью cat ................................................................ 146
Команды head и tail ............................................................................................. 147
Вырезание текста с помощью cut ....................................................................... 148
Потоковый редактор sed ..................................................................................... 149
Потоковый редактор awk .................................................................................... 152
Сравнение файлов и каталогов .......................................................................... 154
Замена символов табуляции на пробелы ............................................................ 156
Простое форматирование текста ....................................................................... 157
Подготовка текста к печати ................................................................................ 157
Сортировка строк ................................................................................................ 158
Вывод неповторяющихся строк .......................................................................... 159
Объединение строк двух файлов по общему полю ........................................... 160
Подсчет количества и нумерация строк ............................................................ 160
Замена символов с помощью команды tr ............................................................. 161
Слияние строк ...................................................................................................... 164
Получение дампа ................................................................................................. 165
Разделение файлов на части ............................................................................... 166
Команда xargs ...................................................................................................... 168
Глава 9. Регулярные выражения ........................................................................ 169
Классификация регулярных выражений ........................................................... 169
Поиск текста с помощью grep ............................................................................ 171
Использование обратных ссылок ....................................................................... 175
Использование регулярных выражений с sed ................................................... 177
Регулярные выражения в awk ............................................................................ 179
Глава 10. Написание сценариев Bash ................................................................ 181
Сценарии оболочки ............................................................................................. 181
Использование переменных оболочки ................................................................ 183
Экранирование (quotation) .................................................................................. 186
Интерактивная установка значений переменных .............................................. 187
Позиционные параметры .................................................................................... 188
Команда test ......................................................................................................... 191
Условное исполнение команд .............................................................................. 194
Команда case ........................................................................................................ 198
Циклы ................................................................................................................... 199
Функции ............................................................................................................... 203
ЧАСТЬ IV. АДМИНИСТРИРОВАНИЕ ....................................................................... 207
Глава 11. Работа с носителями информации .................................................. 209
Физическая структура накопителя на жестких магнитных дисках ................ 209
Имена жестких магнитных дисков .................................................................... 211
Создание разделов с использованием fdisk ....................................................... 213
Создание файловой системы .............................................................................. 216
Проверка целостности файловой системы ....................................................... 219
Монтирование файловых систем ....................................................................... 221
Работа с разделом подкачки ............................................................................... 224
Файл информации о файловых системах /etc/fstab .......................................... 227
Мониторинг дисковых ресурсов ........................................................................ 229
Глава 12. Резервное копирование ..................................................................... 231
Планирование резервного копирования ........................................................... 231
Команда dd ........................................................................................................... 233
Утилиты для сжатия файлов ............................................................................... 234
Команда tar .......................................................................................................... 236
Команда cpio ........................................................................................................ 239
Команда pax ......................................................................................................... 241
Программы dump и restore ................................................................................. 243
Глава 13. Запуск, останов GNU/Linux и уровни выполнения .............................. 246
Инициализация операционной системы и переход на заданный
уровень исполнения ............................................................................................ 246
Остановка и перезагрузка системы ................................................................... 251
Глава 14. Загрузчики .......................................................................................... 254
Последовательность процесса загрузки ............................................................ 254
Загрузчик GRUB .................................................................................................. 255
Загрузчик LILO .................................................................................................... 258
Глава 15. Отложенное и регулярное выполнение заданий .............................. 262
Отложенное выполнение заданий ..................................................................... 262
Автоматизация выполнения регулярных задач .................................................. 264
Глава 16. Системные журналы ............................................................................ 267
Служба syslog ...................................................................................................... 267
Служба ротации журналов ................................................................................. 271
Глава 17. Управление пользователями ............................................................... 273
Хранение учетных записей пользователей ....................................................... 273
Регистрация, удаление и блокирование учетных записей пользователей ..... 274
Управление паролями ......................................................................................... 279
Управление группами пользователей ............................................................... 280
Профили пользователей ..................................................................................... 282
Квотирование дискового пространства............................................................. 285
Мониторинг активности пользователей ........................................................... 291
Глава 18. Управление программным обеспечением ......................................... 293
В чем состоит управление программным обеспечением? ................................ 293
Сборка и установка программного обеспечения из пакетов
с исходным кодом ............................................................................................... 296
Управление библиотеками ................................................................................. 299
Менеджер пакетов RPM ..................................................................................... 303
Система управления пакетами Debian .............................................................. 308
Глава 19. Установка аппаратного обеспечения ............................................... 315
Установка нового оборудования ....................................................................... 315
Работа с модулями ядра ...................................................................................... 316
Файлы устройств и udev ..................................................................................... 321
Устройства PCI .................................................................................................... 325
Установка SCSI-устройств .................................................................................. 326
Установка сетевых адаптеров Ethernet.............................................................. 327
Работа со звуковыми картами ............................................................................ 329
Поддержка USB ................................................................................................... 330
Устройства PCMCIA .............................................................................................. 331
Сборка и установка ядра Linux ........................................................................... 331
ЧАСТЬ V. СЕТИ ....................................................................................................... 337
Глава 20. Сетевые средства GNU/Linux ............................................................... 339
TCP/IP ................................................................................................................... 339
Адресация IPv4 .................................................................................................... 341
Адресация IPv6 .................................................................................................... 344
Настройка сетевого интерфейса Ethernet .......................................................... 346
Настройка маршрутизатора по умолчанию ........................................................ 347
Настройка разрешения имен .............................................................................. 350
Поиск и устранение проблем с сетью ................................................................. 353
Глава 21. Сервисы сети ....................................................................................... 356
Идентификация служб сети................................................................................ 356
Запуск сетевых служб ......................................................................................... 358
Использование супердемона inetd и фильтра tcpd ........................................... 359
Программа tcpd .................................................................................................... 360
Использование супердемона xinetd ................................................................... 362
Глава 22. Службы удаленного доступа .............................................................. 367
Служба telnet ...................................................................................................... 367
Службы удаленного доступа (r-services)............................................................ 370
Система SSH ........................................................................................................ 373
Глава 23. Служба FTP .......................................................................................... 378
Как работает служба FTP ................................................................................... 378
Настройка сервера vsftpd .................................................................................... 379
Клиенты FTP ........................................................................................................ 381
Глава 24. Файловая система NFS ........................................................................ 384
Настройка сервера NFS ...................................................................................... 384
Использование сервера NFS ............................................................................... 386
Отличия протокола NFSv4 ................................................................................. 388
Глава 25. SMB/CIFS-сервер SAMBA .................................................................... 390
Состав пакета SAMBA ........................................................................................ 390
Настройка SAMBA .............................................................................................. 391
Запуск и работа системы SAMBA ....................................................................... 394
Монтирование файловых ресурсов SMB ........................................................... 397
Использование сетевых принтеров ................................................................... 398
Запуск SAMBA в режиме PDC ............................................................................. 399
Сервер SAMBA в режиме члена домена ............................................................ 401
Программа winbind .............................................................................................. 402
Глава 26. DNS-сервер BIND.................................................................................. 404
Организация DNS ................................................................................................ 404
Конфигурационный файл BIND .......................................................................... 407
Записи о ресурсах DNS ....................................................................................... 409
Запуск DNS-сервера BIND ................................................................................... 416
Тестирование сервера DNS ................................................................................ 417
Делегирование ................................................................................................... 419
Журналы DNS ...................................................................................................... 420
Глава 27. Сервер DHCP ....................................................................................... 423
Работа DHCP ........................................................................................................ 423
Настройка сервера DHCP .................................................................................... 424
Глава 28. Web-сервер Apache ............................................................................. 426
Конфигурационный файл Apache ....................................................................... 426
Контейнеры .......................................................................................................... 431
Запуск и управление Apache .............................................................................. 433
Личные Web-страницы ....................................................................................... 434
Ограничение доступа к Web-ресурсу ................................................................ 436
Виртуальные узлы ............................................................................................... 438
Глава 29. Электронная почта ............................................................................. 440
Организация электронной почты ....................................................................... 440
Файл конфигурации программы Sendmail .......................................................... 442
Файл конфигурации sendmail.mc ....................................................................... 446
Запуск Sendmail ................................................................................................... 450
Почтовые псевдонимы ........................................................................................ 452
Очередь почтовых сообщений ........................................................................... 454
Тестирование Sendmail ....................................................................................... 455
Преимущества использования Postfix ............................................................... 458
Конфигурационные файлы Postfix .................................................................... 462
Виртуальный хостинг ......................................................................................... 465
POP3/IMAP-сервер Dovecot ............................................................................... 466
Глава 30. Печать в GNU/Linux ............................................................................ 471
Система печати CUPS ......................................................................................... 471
Команды CUPS .................................................................................................... 473
Управление принтерами в CUPS ....................................................................... 475
Управление очередью печати .......................................................................... 477
Глава 31. Сервер NTP ......................................................................................... 480
Сервис синхронизации времени ........................................................................ 480
Утилита ntpdate ................................................................................................... 481
Пакет ntp............................................................................................................... 482
Глава 32. Система X Window ................................................................................ 484
Организация X Window ....................................................................................... 484
Конфигурирование X Window ............................................................................ 486
Сервер шрифтов .................................................................................................. 491
Запуск X-сервера из командной строки ............................................................. 493
Менеджер X-сеанса xdm ..................................................................................... 497
X-приложения ...................................................................................................... 499
Шрифты ................................................................................................................ 500
Ресурсы X-приложений ...................................................................................... 502
Удаленный запуск X-приложений ..................................................................... 504
Использование xdm для удаленного входа в сеанс .......................................... 507
ПРИЛОЖЕНИЯ .................................................................................................... 511
Приложение 1. Работа с VMWare Workstation и Sun VirtualBox ...................... 513
Создание виртуальной машины в Sun VirtualBox ............................................. 513
Создание виртуальной машины в VMWare Workstation ................................... 518
Приложение 2. Примеры использования текстовых утилит GNU ..................... 523
Копирование с помощью команды tee .............................................................. 523
Нумерация строк с помощью команды cat ........................................................ 524
Нумерация строк с помощью команды nl ........................................................... 525
Команда csplit ...................................................................................................... 525
Команда sed.......................................................................................................... 527
Команда tac .......................................................................................................... 527
Команда awk ........................................................................................................ 528
Команды expand и unexpand ............................................................................... 528
Команда pr ........................................................................................................... 529
Команды sort и uniq ............................................................................................ 530
Команда wc .......................................................................................................... 530
Команда tr ............................................................................................................ 530
Команда grep........................................................................................................ 531
Приложение 3. Пример использования telnet
для тестирования MTA ......................................................................................... 532
Приложение 4. Пример файлов конфигурации и описания зон
сервера DNS BIND ................................................................................................ 533
Конфигурация named .......................................................................................... 533
Зона указателей на корневые серверы .............................................................. 535
Зона localhost ....................................................................................................... 538
Обратная зона для 127.0.0 .................................................................................. 538
Зона class.edu ....................................................................................................... 539
Обратная зона для 192.168.0 .............................................................................. 539
Приложение 5. Сложные варианты установки GNU/Linux .................................. 540
Требования к аппаратному обеспечению для установки GNU/Linux
на платформе x86/64 ............................................................................................ 540
Подготовка к установке GNU/Linux на компьютерах
с архитектурой x86/64 ......................................................................................... 542
Установка GNU/Linux ............................................................................................ 548
Приложение 6. Описание компакт-диска ............................................................ 550
Предметный указатель ......................................................................................... 551

Оглавление

Preface
Part 1: Red Hat Linux 8 –Configuring and Maintaining Storage with Automation
Chapter 1: Block Storage – Learning How to Provision Block Storage on Red Hat Enterprise Linux
Chapter 2: Network File Storage – Expanding Your Knowledge of How to Share Data
Part 2: Red Hat Linux 8 – Configuring and Maintaining Networking with Automation
Chapter 3: Network Services with Automation – Introduction to Red Hat Linux Networking
Chapter 4: Link Aggregation Creation – Creating Your Own Link and Mastering the Networking Domain
Chapter 5: DNS, DHCP, and IP Addressing – Gaining Deeper Knowledge of Red Hat Linux Networking
Part 3: Red Hat Linux 8 – Configuring and Maintaining Applications with Automation and a Comprehensive Review with Exam Tips
Chapter 6: Printer and Email – Setting Up Printers and Email Services on Linux Servers
Chapter 7: Databases – Setting Up and Working with MariaDB SQL Databases
Chapter 8: Web Servers and Web Traffic – Learning How to Create and Control Traffic
Chapter 9: Comprehensive Review and Test Exam Questions
Chapter 10: Tips and Tricks to Help with the Exam
Index
Other Books You May Enjoy

Примеры страниц

Оглавление

Preface xxi
Section I: Setting up a Secure Linux System 1
Chapter 1: Running Linux in a Virtual Environment 3
Looking at the threat landscape 4
Why do security breaches happen? 4
Keeping up with security news 5
Differences between physical, virtual, and cloud setups 6
Introducing VirtualBox and Cygwin 6
Installing a virtual machine in VirtualBox • 7
Installing the EPEL repository on the CentOS 7 virtual machine • 11
Installing the EPEL repository on the AlmaLinux 8/9 virtual machines • 12
Configuring a network for VirtualBox virtual machines • 13
Creating a virtual machine snapshot with VirtualBox • 14
Using Cygwin to connect to your virtual machines • 14
Installing Cygwin on your Windows host • 14
Using the Windows 10 SSH client to interface with Linux virtual machines • 15
Using the Windows 11 SSH client to interface with Linux virtual machines • 18
Cygwin versus the Windows shell • 18
Keeping the Linux systems updated 19
Updating Debian-based systems • 19
Configuring auto updates for Ubuntu • 20
Updating Red Hat 7-based systems • 22
Updating Red Hat 8/9-based systems • 26
Managing updates in an enterprise • 27
Summary 27
Questions 28
Further reading 28
Answers 29
Chapter 2: Securing Administrative User Accounts 31
The dangers of logging in as the root user 31
The advantages of using sudo 32
Setting up sudo privileges for full administrative users 33
Adding users to a predefined admin group • 33
Creating an entry in the sudo policy file • 35
Setting up sudo for users with only certain delegated privileges 36
Hands-on lab for assigning limited sudo privileges • 39
Advanced tips and tricks for using sudo 41
The sudo timer • 41
View your sudo privileges • 41
Hands-on lab for disabling the sudo timer • 42
Preventing users from having root shell access • 43
Preventing users from using shell escapes • 43
Preventing users from using other dangerous programs • 46
Limiting the user’s actions with commands • 47
Letting users run as other users • 47
Preventing abuse via a user’s shell scripts • 48
Detecting and deleting default user accounts • 50
New sudo features 51
Special sudo considerations for SUSE and OpenSUSE 51
Summary 53
Questions 54
Further reading 55
Answers 55
Chapter 3: Securing Normal User Accounts 57
Locking down users’ home directories the Red Hat way 57
Locking down users’ home directories the Debian/Ubuntu way 58
useradd on Debian/Ubuntu • 59
adduser on Debian/Ubuntu • 60
Hands-on lab for creating an encrypted home directory with adduser • 61
Enforcing strong password criteria 62
Installing and configuring pwquality • 63
Hands-on lab for setting password complexity criteria • 65
Setting and enforcing password and account expiration 66
Configuring default expiry data for useradd for Red Hat-type systems only 67
Setting expiry data on a per-account basis with useradd and usermod 69
Setting expiry data on a per-account basis with chage 70
Hands-on lab for setting account and password expiry data • 72
Preventing brute-force password attacks 73
Configuring the pam_tally2 PAM module on CentOS 7 • 73
Hands-on lab for configuring pam_tally2 on CentOS 7 • 74
Configuring pam_faillock on AlmaLinux 8/9 • 75
Hands-on lab for configuring pam_faillock on AlmaLinux 8 or AlmaLinux 9 • 75
Configuring pam_faillock on Ubuntu 20.04 and Ubuntu 22.04 • 77
Hands-on lab for configuring pam_faillock on Ubuntu 20.04 and Ubuntu 22.04 • 77
Locking user accounts 78
Using usermod to lock a user account • 78
Using passwd to lock user accounts • 79
Locking the root user account 80
Setting up security banners 80
Using the motd file • 81
Using the issue file • 82
Using the issue.net file • 83
Detecting compromised passwords 83
Hands-on lab for detecting compromised passwords • 86
Understanding centralized user management 87
Microsoft Active Directory • 87
Samba on Linux 87
FreeIPA/Identity Management on RHEL-type distros • 88
Summary 90
Questions 90
Further reading 91
Answers 91
Chapter 4: Securing Your Server with a Firewall – Part 1 93
Technical requirements 93
An overview of the Linux firewall 94
An overview of iptables 95
x Table of Contents
Mastering the basics of iptables • 95
Blocking ICMP with iptables • 99
Blocking everything that isn’t allowed with iptables • 101
Hands-on lab for basic iptables usage • 104
Blocking invalid packets with iptables • 105
Restoring the deleted rules • 111
Hands-on lab for blocking invalid IPv4 packets • 112
Protecting IPv6 • 113
Hands-on lab for ip6tables • 116
nftables – a more universal type of firewall system 117
Learning about nftables tables and chains • 118
Getting started with nftables • 118
Configuring nftables on Ubuntu • 118
Using nft commands • 122
Hands-on lab for nftables on Ubuntu • 127
Summary 129
Questions 129
Further reading 130
Answers 130
Chapter 5: Securing Your Server with a Firewall — Part 2 131
Technical requirements 132
The Uncomplicated Firewall for Ubuntu systems 132
Configuring ufw • 132
Working with the ufw configuration files • 134
Hands-on lab for basic ufw usage • 137
firewalld for Red Hat systems 139
Verifying the status of firewalld • 140
Working with firewalld zones • 140
Adding services to a firewalld zone • 144
Adding ports to a firewalld zone • 149
Blocking ICMP • 150
Using panic mode • 152
Logging dropped packets • 153
Using firewalld rich language rules • 154
Looking at iptables rules in RHEL/CentOS 7 firewalld • 156
Creating direct rules in RHEL/CentOS 7 firewalld • 158
Table of Contents xi
Looking at nftables rules in RHEL/AlmaLinux 8 and 9 firewalld • 161
Creating direct rules in RHEL/AlmaLinux firewalld • 161
Hands-on lab for firewalld commands • 162
Summary 165
Questions 165
Further reading 166
Answers 166
Chapter 6: Encryption Technologies 167
GNU Privacy Guard (GPG) 168
Hands-on lab – creating your GPG keys • 169
Hands-on lab – symmetrically encrypting your own files • 171
Hands-on lab – encrypting files with public keys • 173
Hands-on lab – signing a file without encryption • 177
Encrypting partitions with Linux Unified Key Setup (LUKS) 178
Disk encryption during operating system installation • 179
Hands-on lab – adding an encrypted partition with LUKS • 181
Configuring the LUKS partition to mount automatically • 185
Hands-on lab – configuring the LUKS partition to mount automatically • 186
Encrypting directories with eCryptfs 187
Hands-on lab – encrypting a home directory for a new user account • 188
Creating a private directory within an existing home directory • 188
Hands-on lab – encrypting other directories with eCryptfs • 190
Encrypting the swap partition with eCryptfs 192
Using VeraCrypt for cross-platform sharing of encrypted containers 192
Hands-on lab – getting and installing VeraCrypt • 193
Hands-on lab – creating and mounting a VeraCrypt volume in console mode • 194
Using VeraCrypt in GUI mode • 196
OpenSSL and the Public Key Infrastructure 197
Commercial certificate authorities • 198
Creating keys, certificate signing requests, and certificates • 201
Creating a self-signed certificate with an RSA key • 201
Creating a self-signed certificate with an Elliptic Curve key • 202
Creating an RSA key and a Certificate Signing Request • 203
Creating an EC key and a CSR • 204
Creating an on-premises CA • 205
Hands-on lab – setting up a Dogtag CA • 206
xii Table of Contents
Adding a CA to an operating system • 210
Hands-on lab – exporting and importing the Dogtag CA certificate • 210
Importing the CA into Windows • 211
OpenSSL and the Apache webserver • 212
Hardening Apache SSL/TLS on Ubuntu • 212
Hardening Apache SSL/TLS on RHEL 9/AlmaLinux 9 • 213
Setting FIPS mode on RHEL 9/AlmaLinux 9 • 215
Hardening Apache SSL/TLS on RHEL 7/CentOS 7 • 217
Setting up mutual authentication • 218
Introducing quantum-resistant encryption algorithms 218
Summary 219
Questions 219
Further reading 220
Answers 221
Chapter 7: SSH Hardening 223
Ensuring that SSH protocol 1 is disabled 224
Creating and managing keys for passwordless logins 224
Creating a user’s SSH key set • 225
Transferring the public key to the remote server • 228
Hands-on lab – creating and transferring SSH keys • 230
Disabling root user login • 231
Disabling username/password logins • 232
Hands-on lab – Disabling root login and password authentication • 232
Enabling two-factor authentication • 233
Hands-on lab — Setting up two-factor authentication on Ubuntu 22.04 • 234
Hands-on lab – Using Google Authenticator with key exchange on Ubuntu • 236
Hands-on lab — Setting up two-factor authentication on AlmaLinux 8 • 237
Hand-on lab — Using Google Authenticator with key exchange on AlmaLinux 8 • 238
Configuring Secure Shell with strong encryption algorithms • 238
Understanding SSH encryption algorithms • 239
Scanning for enabled SSH algorithms • 242
Hands-on lab – Scanning with Nmap • 242
Disabling weak SSH encryption algorithms • 243
Hands-on lab – disabling weak SSH encryption algorithms – Ubuntu 22.04 • 243
Hands-on lab – disabling weak SSH encryption algorithms – CentOS 7 • 244
Setting system-wide encryption policies on RHEL 8/9 and AlmaLinux 8/9 • 246
Table of Contents xiii
Hands-on lab – setting encryption policies on AlmaLinux 9 • 247
Configuring more detailed logging • 248
Hands-on lab – configuring more verbose SSH logging • 249
Configuring access control with whitelists and TCP Wrappers 250
Configuring whitelists within sshd_config • 251
Hands-on lab – configuring whitelists within sshd_config • 251
Configuring whitelists with TCP Wrappers • 252
Configuring automatic logouts and security banners 254
Configuring automatic logout for both local and remote users • 254
Configuring automatic logout in sshd_config • 254
Creating a pre-login security banner • 255
Configuring other miscellaneous security settings 255
Disabling X11 forwarding • 255
Disabling SSH tunneling • 256
Changing the default SSH port • 257
Managing SSH keys • 258
Setting different configurations for different users and groups 261
Creating different configurations for different hosts 261
Setting up a chroot environment for SFTP users 262
Creating a group and configuring the sshd_config file • 263
Hands-on lab – Setting up a chroot directory for the sftpusers group • 264
Sharing a directory with SSHFS 265
Hands-on lab – Sharing a directory with SSHFS • 265
Remotely connecting from Windows desktops 267
Summary 272
Questions 273
Further reading 275
Answers 275
Section II: Mastering File and
Directory Access Control (DAC) 277
Chapter 8: Mastering Discretionary Access Control 279
Using chown to change ownership of files and directories • 279
Using chmod to set permissions on files and directories • 281
Setting permissions with the symbolic method • 282
Setting permissions with the numerical method • 282
xiv Table of Contents
Using SUID and SGID on regular files • 284
The security implications of the SUID and SGID permissions • 285
Finding spurious SUID or SGID files • 286
Preventing SUID and SGID usage on a partition • 288
Using extended file attributes to protect sensitive files • 288
Setting the a attribute • 290
Setting the i attribute • 291
Securing system configuration files • 293
Summary 295
Questions 295
Further reading 298
Answers 298
Chapter 9: Access Control Lists and Shared Directory Management 301
Creating an ACL for either a user or a group 301
Creating an inherited ACL for a directory 304
Removing a specific permission by using an ACL mask 306
Using the tar --acls option to prevent the loss of ACLs during a backup 307
Creating a user group and adding members to it 309
Adding members as we create their user accounts • 310
Using usermod to add an existing user to a group • 310
Adding users to a group by editing the /etc/group file • 310
Creating a shared directory 311
Setting the SGID bit and the sticky bit on the shared directory 312
Using ACLs to access files in the shared directory 315
Setting the permissions and creating the ACL • 315
Hands-on lab – creating a shared group directory • 317
Summary 318
Questions 318
Further reading 320
Answers 321
Table of Contents xv
Section III: Advanced System Hardening Techniques 323
Chapter 10: Implementing Mandatory Access Control with
SELinux and AppArmor 325
How SELinux can benefit a systems administrator 326
Setting security contexts for files and directories 327
Installing the SELinux tools • 328
Creating web content files with SELinux enabled • 329
Fixing an incorrect SELinux context • 332
Using chcon • 332
Using restorecon • 333
Using semanage • 334
Hands-on lab – SELinux type enforcement • 336
Troubleshooting with setroubleshoot 337
Viewing setroubleshoot messages • 337
Using the graphical setroubleshoot utility • 338
Troubleshooting in permissive mode • 340
Working with SELinux policies 342
Viewing Booleans • 342
Configuring the Booleans • 344
Protecting your web server • 345
Protecting network ports • 346
Creating custom policy modules • 349
Hands-on lab – SELinux Booleans and ports • 351
How AppArmor can benefit a systems administrator 351
Looking at AppArmor profiles • 352
Working with AppArmor command-line utilities • 355
Troubleshooting AppArmor problems • 358
Troubleshooting an AppArmor profile – Ubuntu 16.04 • 358
Troubleshooting an AppArmor profile – Ubuntu 18.04 • 361
Hands-on lab – Troubleshooting an AppArmor profile • 362
Troubleshooting Samba problems in Ubuntu 22.04 • 363
xvi Table of Contents
Exploiting a system with an evil Docker container 364
Hands-on lab – Creating an evil Docker container • 364
Summary 366
Questions 367
Further reading 369
Answers 369
Chapter 11: Kernel Hardening and Process Isolation 371
Understanding the /proc filesystem 372
Looking at user-mode processes • 372
Looking at kernel information • 374
Setting kernel parameters with sysctl 376
Configuring the sysctl.conf file 377
Configuring sysctl.conf – Ubuntu • 378
Configuring sysctl.conf – CentOS and AlmaLinux • 381
Setting additional kernel-hardening parameters • 382
Hands-on lab – scanning kernel parameters with Lynis • 383
Preventing users from seeing each others’ processes • 385
Understanding process isolation 386
Understanding Control Groups (cgroups) • 387
Understanding namespace isolation • 390
Understanding kernel capabilities • 391
Hands-on lab – setting a kernel capability • 395
Understanding SECCOMP and system calls • 396
Using process isolation with Docker containers • 397
Sandboxing with Firejail • 398
Hands-on lab – using Firejail • 400
Sandboxing with Snappy • 401
Sandboxing with Flatpak • 405
Summary ����������������������������������������������������������������������������������������������������������������������������� 408
Questions ����������������������������������������������������������������������������������������������������������������������������� 408
Further reading �������������������������������������������������������������������������������������������������������������������� 410
Answers ������������������������������������������������������������������������������������������������������������������������������� 411
Chapter 12: Scanning, Auditing, and Hardening 413
Installing and updating ClamAV and maldet �������������������������������������������������������������������������� 414
Hands-on lab – installing ClamAV and maldet • 415
Table of Contents xvii
Hands-on lab – configuring maldet • 416
Updating ClamAV and maldet • 418
Scanning with ClamAV and maldet ���������������������������������������������������������������������������������������� 420
SELinux considerations • 421
Scanning for rootkits with Rootkit Hunter ����������������������������������������������������������������������������� 422
Hands-on lab – installing and updating Rootkit Hunter • 423
Scanning for rootkits • 424
Performing a quick malware analysis with strings and VirusTotal ������������������������������������������� 424
Analyze a file with strings • 425
Scanning the malware with VirusTotal • 426
Understanding the auditd daemon ���������������������������������������������������������������������������������������� 427
Creating audit rules • 428
Auditing a file for changes • 428
Auditing a directory • 430
Auditing system calls • 431
Using ausearch and aureport ������������������������������������������������������������������������������������������������ 432
Searching for file change alerts • 432
Searching for directory access rule violations • 434
Searching for system call rule violations • 439
Generating authentication reports • 441
Using pre-defined rulesets • 442
Hands-on lab – using auditd • 444
Hands-on lab –Using pre-configured rules with auditd • 445
Auditing files and directories with inotifywait ������������������������������������������������������������������������ 446
Applying OpenSCAP policies with oscap �������������������������������������������������������������������������������� 447
Installing OpenSCAP • 447
Viewing the profile files • 448
Getting the missing profiles for Ubuntu • 449
Scanning the system • 449
Remediating the system • 451
Using SCAP Workbench • 453
Choosing an OpenSCAP profile • 455
Applying an OpenSCAP profile during system installation • 456
Summary ����������������������������������������������������������������������������������������������������������������������������� 458
Questions ����������������������������������������������������������������������������������������������������������������������������� 458
Further reading �������������������������������������������������������������������������������������������������������������������� 460
Answers ������������������������������������������������������������������������������������������������������������������������������� 460
xviii Table of Contents
Chapter 13: Logging and Log Security 461
Understanding the Linux system log files ������������������������������������������������������������������������������ 461
The system log and the authentication log • 462
The utmp, wtmp, btmp, and lastlog files • 465
Understanding rsyslog ���������������������������������������������������������������������������������������������������������� 467
Understanding rsyslog logging rules • 467
Understanding journald ������������������������������������������������������������������������������������������������������� 469
Making things easier with Logwatch ������������������������������������������������������������������������������������� 472
Hands-on lab – installing Logwatch • 472
Setting up a remote log server ����������������������������������������������������������������������������������������������� 473
Hands-on lab – setting up a basic log server • 474
Creating an encrypted connection to the log server • 475
Creating a stunnel connection on AlmaLinux 9 – server side • 475
Creating a stunnel connection on AlmaLinux – client side • 477
Creating a stunnel connection on Ubuntu – server side • 478
Creating a stunnel connection on Ubuntu – client side • 479
Separating client messages into their own files • 480
Maintaining Logs in Large Enterprises ���������������������������������������������������������������������������������� 481
Summary ����������������������������������������������������������������������������������������������������������������������������� 481
Questions ����������������������������������������������������������������������������������������������������������������������������� 482
Further reading �������������������������&#6553

Примеры страниц

Оглавление

Preface xiii
Part 1: The Fedora Project
1
Linux and Open Source Projects 3
A brief history of Linux 3
Understanding Linux distributions 5
The Fedora Project 7
The Red Hat contribution path 8
Fedora’s mission and foundations 9
Contributing to the project 10
Fedora as a system administration tool 15
The command-line interface 16
The basics 17
Guided example – releasing space in the filesystem 30
Desktop environments 34
Summary 34
Further reading 35
Part 2: Workstation Configuration
2
Best Practices for Installation 39
Technical requirements 39
Creating the boot media 40
Fedora Media Writer 40
Booting 46
Partitioning local storage 51
The first startup 54
Package management 64
Extra package selection 69
Summary 72
Further reading 72
3
Tuning the Desktop Environment 73
Technical requirements 73
Initial system tuning 74
Tuning the swappiness value 74
Tuning the desktop experience 75
GNOME Tweak Tool 78
Customizing the panel and the taskbar 84
The taskbar 88
Making tasks easy with widgets 94
Conky 97
Handy applications with docks 104
Summary 106
Further reading 107
4
Optimizing Storage Usage 109
Technical requirements 109
Understanding file formats and
filesystems 110
Creating a Btrfs filesystem 111
Optimizing storage space size 117
Space allocation check 120
Using the btrfs-usage-report command 124
Deep diving into Logical Volume
Manager 127
Differences between snapshots 129
Discovering Stratis storage 131
Creating a Stratis pool 132
Summary 136
Further reading 137
5
Network and Connectivity 139
Technical requirements 139
Walking through the basics 140
NetworkManager command-line interface
(nmcli) 141
Tuning wireless connectivity 149
Identifying the device 149
Finding the best quality network connection 153
nm-connection-editor 157
What about security? 161
Improving network connectivity
using a VPN 165
IPSec-based VPN 166
OpenVPN 166
Configuring a VPN client with the Control
Center 167
Network performance monitoring 175
nmon 175
bpytop 177
Summary 178
Further reading 179
Part 3: Productivity Tools
6
Sandbox Applications 183
Technical requirements 183
Inspecting sandbox applications 184
SELinux sandbox 184
Diving deep into AppImage apps 189
Running an AppImage 189
Developing AppImages 194
Examining Flatpak applications 196
Using Flatpak applications 197
Building Flatpak applications 213
Summary 218
Further reading 218
7
Text Editors 219
Technical requirements 219
Text editors and the command line 220
Emacs overview 221
The basics 223
Mastering GNU Emacs 228
Nano basics 244
The mighty vim 246
The basics 247
Mastering vim 251
Summary 269
Further reading 269
8
LibreOffice Suite 271
Technical requirements 271
Exploring office tools on Fedora
Linux 272
WPS Office 272
ONLYOFFICE 272
Calligra 273
Fonts 274
LibreOffice 276
Getting used to Writer and Calc 279
Writer 280
Calc 291
Creating slides and image
management 294
Summary 298
Further reading 299
9
Mail Clients and Browsers 301
Technical requirements 302
Mailing with Evolution 302
Mailing with Thunderbird 315
Trusty old Firefox 327
Customizing Firefox 335
Expanding browsing with Google
Chrome 344
Summary 365
Further reading 365
Part 4: System Administration Tools
10
System Administration 369
Technical requirements 369
The three laws of the SysAdmin 370
The KISS principle 370
Knowing the basic tasks 371
A little bit of Git and programming 373
Bash scripting 373
Git 386
The basics 388
Don’t forget to back up 400
Archiving and compression 400
Version management with Git 405
Automating with Ansible 414
The basics 415
First steps 416
Never-ending study 424
Summary 428
11
Performance Tuning Best Practices 429
Technical requirements 429
Understanding kernel tuning 430
Tuning kernel parameters 430
Main tuning – CPU and memory 435
Overview of monitoring tools 435
Improving CPU usage 441
Improving memory usage 448
Don’t ignore storage tuning 452
Improving storage space usage 454
Boosting performance with network
tuning 462
Analyzing metrics 463
Summary 474
12
Untangling Security with SELinux 475
Technical requirements 475
Learning about mandatory access
control 476
Labeling and type enforcement 477
How SELinux works 478
How to troubleshoot SELinux issues 483
Labeling 485
SELinux needs to know 486
Policy bugs 488
Hack attack 488
Summary 489
Further reading 489
13
Virtualization and Containers 491
Technical requirements 491
Virtualization with QEMU, KVM,
and libvirt 492
Management tools 492
Streamlining the creation of virtual machines 494
Using GNOME Boxes 501
Discovering OCI containers
with Podman 512
Summary 527
Further reading 527
Index 529
Other Books You May Enjoy 538