cap_get_bound - Linux

Overview

The cap_get_bound() command fetches the capabilities bounding set for an existing process. It inspects the kernel’s internal data structures and extracts the bounding set from the process’s thread group or thread structure. This information is crucial for understanding and managing the process’s capabilities.

Syntax

int cap_get_bound(pid_t pid, cap_value_t *bound);

Options/Flags

None.

Examples

  1. Retrieve the capability bounding set for the current process:
#include <sys/types.h>
#include <sys/capability.h>
...
cap_value_t bound;
if (cap_get_bound(0, &bound) == -1) {
    perror("cap_get_bound()");
    exit(EXIT_FAILURE);
}
...
  1. Get the bounding set for a specific process:
#include <sys/types.h>
#include <sys/capability.h>
...
pid_t target_pid = 1234;
cap_value_t bound;
if (cap_get_bound(target_pid, &bound) == -1) {
    perror("cap_get_bound()");
    exit(EXIT_FAILURE);
}
...

Common Issues

  • Permission denied: cap_get_bound() requires the calling process to have the CAP_SYS_ADMIN capability or sufficient privilege to inspect the target process.

  • Invalid PID: If the specified pid does not belong to an existing process, cap_get_bound() will return an error.

Integration

The cap_get_bound() command can be integrated with other Linux commands and tools, such as:

  • **cap_set_bound(): Sets the capability bounding set for a process.
  • **getpid(): Obtains the PID of the current process.
  • **ps -p: Displays information about running processes, including their PIDs.

Related Commands