Attachment 583470 Details for Bug 745775 – Corrected problem demo program

Corrected problem demo program

nsdemo.c (text/plain), 1.75 KB, created by Ian Kent on 2012-05-10 08:01:34 UTC

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Filename:

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Creator: Ian Kent

Created: 2012-05-10 08:01:34 UTC

Size: 1.75 KB

patch

obsolete

>
>#define _GNU_SOURCE
>#include <sys/mount.h>
>#include <signal.h>
>#include <sched.h>
>#include <linux/fs.h>
>#include <string.h>
>#include <unistd.h>
>#include <stdlib.h>
>#include <stdio.h>
>#include <errno.h>
>#include <sys/wait.h>
>#include <mntent.h>
>//#include <sys/mount.h>
>
>char *path;
>
>static int
>containerMain(void *argv)
>{
>  FILE *m;
>  struct mntent *me;
>  int count = 0;
>  fprintf(stderr, "We are the container!\n");
>
>  m = setmntent("/proc/mounts", "r");
>
>  while ((me = getmntent(m)) != NULL) {
>    if (strcmp(me->mnt_dir, path) == 0) {
>      count++;
>      fprintf(stderr, "Mount point %d %s %s %s %s\n",
>	      count, me->mnt_dir, me->mnt_fsname, me->mnt_type, me->mnt_opts);
>    }
>  }
>  endmntent(m);
>
>  for ( ; count > 0 ; count--) {
>    fprintf(stderr, "Umount point %d %s\n", count, path);
>    if (umount (path) < 0) {
>      fprintf(stderr, "Could not umount %s: %s\n",
>	      path, strerror(errno));
>      exit(1);
>    }
>  }
>
>  fprintf(stderr, "Done with umount\n");
>  _exit(0);
>}
>
>int tryContainer(void)
>{
>    int flags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|
>      CLONE_NEWIPC|SIGCHLD|CLONE_NEWUSER|CLONE_NEWNET;
>    int cpid;
>    char *childStack;
>    char *stack;
>    int childStatus;
>
>    stack = malloc(sizeof(*stack) * getpagesize() * 4);
>    childStack = stack + (getpagesize() * 4);
>
>    cpid = clone(containerMain, childStack, flags, NULL);
>    free(stack);
>    if (cpid < 0) {
>      fprintf(stderr, "clone call returned: %s\n",
>	      strerror(errno));
>      return -1;
>    } else {
>      fprintf(stderr, "We are the parent\n");
>      waitpid(cpid, &childStatus, 0);
>    }
>
>    return 0;
>}
>
>
>int main(int argc, char **argv)
>{
>  if (argc != 2) {
>    fprintf(stderr, "nsdemo /path/to/umount/in/container\n");
>    exit(3);
>  }
>
>  path = argv[1];
>
>  return tryContainer();
>}

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Attachments on bug 745775: 527958 | 558812 | 558813 | 558814 | 558815 | 583470