nixpkgs-suyu/nixos/modules/virtualisation/run-in-netns.c

51 lines
1.2 KiB
C
Raw Normal View History

#define _GNU_SOURCE
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sched.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <fcntl.h>
#include <linux/limits.h>
int main(int argc, char * * argv)
{
if (argc < 3) {
fprintf(stderr, "%s: missing arguments\n", argv[0]);
return 1;
}
char nsPath[PATH_MAX];
sprintf(nsPath, "/run/netns/%s", argv[1]);
int fd = open(nsPath, O_RDONLY);
if (fd == -1) {
fprintf(stderr, "%s: opening network namespace: %s\n", argv[0], strerror(errno));
return 1;
}
if (setns(fd, CLONE_NEWNET) == -1) {
fprintf(stderr, "%s: setting network namespace: %s\n", argv[0], strerror(errno));
return 1;
}
umount2(nsPath, MNT_DETACH);
if (unlink(nsPath) == -1) {
fprintf(stderr, "%s: unlinking network namespace: %s\n", argv[0], strerror(errno));
return 1;
}
/* FIXME: Remount /sys so that /sys/class/net reflects the
interfaces visible in the network namespace. This requires
bind-mounting /sys/fs/cgroups etc. */
execv(argv[2], argv + 2);
fprintf(stderr, "%s: running command: %s\n", argv[0], strerror(errno));
return 1;
}