lttng-sessiond/utils.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License as published by the Free
   7  * Software Foundation; only version 2 of the License.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA  02111-1307, USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <errno.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <unistd.h>
  28
  29 #include <lttngerr.h>
  30
  31 #include "utils.h"
  32
  33 /*
  34  * Write to writable pipe used to notify a thread.
  35  */
  36 int notify_thread_pipe(int wpipe)
  37 {
  38         int ret;
  39
  40         ret = write(wpipe, "!", 1);
  41         if (ret < 0) {
  42                 PERROR("write poll pipe");
  43         }
  44
  45         return ret;
  46 }
  47
  48 /*
  49  * Return pointer to home directory path using the env variable HOME.
  50  *
  51  * No home, NULL is returned.
  52  */
  53 const char *get_home_dir(void)
  54 {
  55         return ((const char *) getenv("HOME"));
  56 }
  57
  58 /*
  59  * Create recursively directory using the FULL path.
  60  */
  61 int mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid)
  62 {
  63         int ret;
  64         char *p, tmp[PATH_MAX];
  65         size_t len;
  66         mode_t old_umask;
  67
  68         ret = snprintf(tmp, sizeof(tmp), "%s", path);
  69         if (ret < 0) {
  70                 PERROR("snprintf mkdir");
  71                 goto error;
  72         }
  73
  74         len = ret;
  75         if (tmp[len - 1] == '/') {
  76                 tmp[len - 1] = 0;
  77         }
  78
  79         old_umask = umask(0);
  80         for (p = tmp + 1; *p; p++) {
  81                 if (*p == '/') {
  82                         *p = 0;
  83                         ret = mkdir(tmp, mode);
  84                         if (ret < 0) {
  85                                 if (!(errno == EEXIST)) {
  86                                         PERROR("mkdir recursive");
  87                                         ret = -errno;
  88                                         goto umask_error;
  89                                 }
  90                         } else if (ret == 0) {
  91                                 /*
  92                                  * We created the directory. Set its ownership to the
  93                                  * user/group specified.
  94                                  */
  95                                 ret = chown(tmp, uid, gid);
  96                                 if (ret < 0) {
  97                                         PERROR("chown in mkdir recursive");
  98                                         ret = -errno;
  99                                         goto umask_error;
 100                                 }
 101                         }
 102                         *p = '/';
 103                 }
 104         }
 105
 106         ret = mkdir(tmp, mode);
 107         if (ret < 0) {
 108                 if (!(errno == EEXIST)) {
 109                         PERROR("mkdir recursive last piece");
 110                         ret = -errno;
 111                 } else {
 112                         ret = 0;
 113                 }
 114         } else if (ret == 0) {
 115                 /*
 116                  * We created the directory. Set its ownership to the user/group
 117                  * specified.
 118                  */
 119                 ret = chown(tmp, uid, gid);
 120                 if (ret < 0) {
 121                         PERROR("chown in mkdir recursive");
 122                         ret = -errno;
 123                         goto umask_error;
 124                 }
 125         }
 126
 127 umask_error:
 128         umask(old_umask);
 129 error:
 130         return ret;
 131 }