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getsockopt

Intro

getsockopt - Queries the state of a socket for the options associated with a given level.

Description

The getsockopt() system call allows a program to determine the current value of an option associated with a socket. This call takes the socket descriptor, the level at which the option is defined, and the number of the option to be retrieved. The value of the option is returned in the buffer pointed to by the optval argument.

There are a number of possible options, depending on the protocol, level and particular option requested. The optlen argument should be initialized to the size of the buffer associated with the optval argument, and modified on return to indicate the actual size of the value returned. If no option value is to be supplied or returned, optval and optlen should be NULL.

Advantages of using getsockopt() include having a flexible and standards-compliant way to query a socket for the value of options associated with it. Likewise, drawbacks stem from being protocol- and implementation-dependent.

Arguments

  • sockfd:int[K] - Specifies a socket created with the socket() system call.
  • level:int[K] - Defines the protocol level at which the option resides. The supported levels include: SOL_SOCKET for options at the socket-level; IPPROTO_IP, IPPROTO_IPV6, IPPROTO_TCP, and IPPROTO_UDP for options at the IP, IPv6, TCP, and UDP levels respectively.
  • optname:int[K] - Defines the type of option. The available types of options depend on the particular protocol in use.
  • optval:void*[K] - Pointer to a buffer which is used to store the option value.
  • optlen:int*[K] - Size of the buffer provided in optval. It is modified on return to indicate the actual size of the option value stored in optval.

Available Tags

  • K - Originated from kernel-space.

Hooks

sys_getsockopt

Type

kprobe

Purpose

Hooked by ftrace to measure execution time and other performance data.

Example Use Case

The getsockopt() system call is commonly used to retrieve information related to network communication, such as socket options, protocol information, and IP address binding.

Issues

No known issues with this system call.

Other socket-related system calls that may be related to getsockopt(): * socket() * bind() * connect() * accept()

This document was automatically generated by OpenAI and needs review. It might not be accurate and might contain errors. The authors of Tracee recommend that the user reads the "events.go" source file to understand the events and their arguments better.