src/shared/dev-setup.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   Copyright 2010-2012 Lennart Poettering
   4 ***/
   5
   6 #include <errno.h>
   7 #include <stdlib.h>
   8 #include <unistd.h>
   9
  10 #include "alloc-util.h"
  11 #include "dev-setup.h"
  12 #include "label.h"
  13 #include "log.h"
  14 #include "path-util.h"
  15 #include "user-util.h"
  16 #include "util.h"
  17
  18 int dev_setup(const char *prefix, uid_t uid, gid_t gid) {
  19         static const char symlinks[] =
  20                 "-/proc/kcore\0"     "/dev/core\0"
  21                 "/proc/self/fd\0"    "/dev/fd\0"
  22                 "/proc/self/fd/0\0"  "/dev/stdin\0"
  23                 "/proc/self/fd/1\0"  "/dev/stdout\0"
  24                 "/proc/self/fd/2\0"  "/dev/stderr\0";
  25
  26         const char *j, *k;
  27         int r;
  28
  29         NULSTR_FOREACH_PAIR(j, k, symlinks) {
  30                 _cleanup_free_ char *link_name = NULL;
  31                 const char *n;
  32
  33                 if (j[0] == '-') {
  34                         j++;
  35
  36                         if (access(j, F_OK) < 0)
  37                                 continue;
  38                 }
  39
  40                 if (prefix) {
  41                         link_name = prefix_root(prefix, k);
  42                         if (!link_name)
  43                                 return -ENOMEM;
  44
  45                         n = link_name;
  46                 } else
  47                         n = k;
  48
  49                 r = symlink_label(j, n);
  50                 if (r < 0)
  51                         log_debug_errno(r, "Failed to symlink %s to %s: %m", j, n);
  52
  53                 if (uid != UID_INVALID || gid != GID_INVALID)
  54                         if (lchown(n, uid, gid) < 0)
  55                                 log_debug_errno(errno, "Failed to chown %s: %m", n);
  56         }
  57
  58         return 0;
  59 }