src/basic/mkdir.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdbool.h>
   5 #include <string.h>
   6
   7 #include "alloc-util.h"
   8 #include "format-util.h"
   9 #include "fs-util.h"
  10 #include "macro.h"
  11 #include "mkdir.h"
  12 #include "path-util.h"
  13 #include "stat-util.h"
  14 #include "stdio-util.h"
  15 #include "user-util.h"
  16
  17 int mkdir_safe_internal(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags, mkdir_func_t _mkdir) {
  18         struct stat st;
  19         int r;
  20
  21         assert(_mkdir != mkdir);
  22
  23         if (_mkdir(path, mode) >= 0) {
  24                 r = chmod_and_chown(path, mode, uid, gid);
  25                 if (r < 0)
  26                         return r;
  27         }
  28
  29         if (lstat(path, &st) < 0)
  30                 return -errno;
  31
  32         if ((flags & MKDIR_FOLLOW_SYMLINK) && S_ISLNK(st.st_mode)) {
  33                 _cleanup_free_ char *p = NULL;
  34
  35                 r = chase_symlinks(path, NULL, CHASE_NONEXISTENT, &p, NULL);
  36                 if (r < 0)
  37                         return r;
  38                 if (r == 0)
  39                         return mkdir_safe_internal(p, mode, uid, gid,
  40                                                    flags & ~MKDIR_FOLLOW_SYMLINK,
  41                                                    _mkdir);
  42
  43                 if (lstat(p, &st) < 0)
  44                         return -errno;
  45         }
  46
  47         if (!S_ISDIR(st.st_mode)) {
  48                 log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
  49                          "Path \"%s\" already exists and is not a directory, refusing.", path);
  50                 return -ENOTDIR;
  51         }
  52         if ((st.st_mode & 0007) > (mode & 0007) ||
  53             (st.st_mode & 0070) > (mode & 0070) ||
  54             (st.st_mode & 0700) > (mode & 0700)) {
  55                 log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
  56                          "Directory \"%s\" already exists, but has mode %04o that is too permissive (%04o was requested), refusing.",
  57                          path, st.st_mode & 0777, mode);
  58                 return -EEXIST;
  59         }
  60         if ((uid != UID_INVALID && st.st_uid != uid) ||
  61             (gid != GID_INVALID && st.st_gid != gid)) {
  62                 char u[DECIMAL_STR_MAX(uid_t)] = "-", g[DECIMAL_STR_MAX(gid_t)] = "-";
  63
  64                 if (uid != UID_INVALID)
  65                         xsprintf(u, UID_FMT, uid);
  66                 if (gid != UID_INVALID)
  67                         xsprintf(g, GID_FMT, gid);
  68                 log_full(flags & MKDIR_WARN_MODE ? LOG_WARNING : LOG_DEBUG,
  69                          "Directory \"%s\" already exists, but is owned by "UID_FMT":"GID_FMT" (%s:%s was requested), refusing.",
  70                          path, st.st_uid, st.st_gid, u, g);
  71                 return -EEXIST;
  72         }
  73
  74         return 0;
  75 }
  76
  77 int mkdir_errno_wrapper(const char *pathname, mode_t mode) {
  78         if (mkdir(pathname, mode) < 0)
  79                 return -errno;
  80         return 0;
  81 }
  82
  83 int mkdirat_errno_wrapper(int dirfd, const char *pathname, mode_t mode) {
  84         if (mkdirat(dirfd, pathname, mode) < 0)
  85                 return -errno;
  86         return 0;
  87 }
  88
  89 int mkdir_safe(const char *path, mode_t mode, uid_t uid, gid_t gid, MkdirFlags flags) {
  90         return mkdir_safe_internal(path, mode, uid, gid, flags, mkdir_errno_wrapper);
  91 }
  92
  93 int mkdir_parents_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
  94         const char *p, *e;
  95         int r;
  96
  97         assert(path);
  98         assert(_mkdir != mkdir);
  99
 100         if (prefix && !path_startswith(path, prefix))
 101                 return -ENOTDIR;
 102
 103         /* return immediately if directory exists */
 104         e = strrchr(path, '/');
 105         if (!e)
 106                 return -EINVAL;
 107
 108         if (e == path)
 109                 return 0;
 110
 111         p = strndupa(path, e - path);
 112         r = is_dir(p, true);
 113         if (r > 0)
 114                 return 0;
 115         if (r == 0)
 116                 return -ENOTDIR;
 117
 118         /* create every parent directory in the path, except the last component */
 119         p = path + strspn(path, "/");
 120         for (;;) {
 121                 char t[strlen(path) + 1];
 122
 123                 e = p + strcspn(p, "/");
 124                 p = e + strspn(e, "/");
 125
 126                 /* Is this the last component? If so, then we're done */
 127                 if (*p == 0)
 128                         return 0;
 129
 130                 memcpy(t, path, e - path);
 131                 t[e-path] = 0;
 132
 133                 if (prefix && path_startswith(prefix, t))
 134                         continue;
 135
 136                 r = _mkdir(t, mode);
 137                 if (r < 0 && r != -EEXIST)
 138                         return r;
 139         }
 140 }
 141
 142 int mkdir_parents(const char *path, mode_t mode) {
 143         return mkdir_parents_internal(NULL, path, mode, mkdir_errno_wrapper);
 144 }
 145
 146 int mkdir_p_internal(const char *prefix, const char *path, mode_t mode, mkdir_func_t _mkdir) {
 147         int r;
 148
 149         /* Like mkdir -p */
 150
 151         assert(_mkdir != mkdir);
 152
 153         r = mkdir_parents_internal(prefix, path, mode, _mkdir);
 154         if (r < 0)
 155                 return r;
 156
 157         r = _mkdir(path, mode);
 158         if (r < 0 && (r != -EEXIST || is_dir(path, true) <= 0))
 159                 return r;
 160
 161         return 0;
 162 }
 163
 164 int mkdir_p(const char *path, mode_t mode) {
 165         return mkdir_p_internal(NULL, path, mode, mkdir_errno_wrapper);
 166 }