src/lxc/storage/rsync.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #define _GNU_SOURCE
  25 #include <grp.h>
  26 #include <sched.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <stdint.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32 #include <sys/types.h>
  33 #include <sys/mount.h>
  34
  35 #include "log.h"
  36 #include "rsync.h"
  37 #include "storage.h"
  38 #include "utils.h"
  39
  40 lxc_log_define(rsync, lxc);
  41
  42 int lxc_storage_rsync_exec_wrapper(void *data)
  43 {
  44         struct rsync_data *arg = data;
  45         return lxc_rsync(arg);
  46 }
  47
  48 int lxc_rsync_exec_wrapper(void *data)
  49 {
  50         int ret;
  51         struct rsync_data_char *args = data;
  52
  53         ret = lxc_switch_uid_gid(0, 0);
  54         if (ret < 0)
  55                 return -1;
  56
  57         ret = lxc_setgroups(0, NULL);
  58         if (ret < 0)
  59                 return -1;
  60
  61         return lxc_rsync_exec(args->src, args->dest);
  62 }
  63
  64 int lxc_rsync_exec(const char *src, const char *dest)
  65 {
  66         int ret;
  67         size_t l;
  68         char *s;
  69
  70         l = strlen(src) + 2;
  71         s = malloc(l);
  72         if (!s)
  73                 return -1;
  74
  75         ret = snprintf(s, l, "%s", src);
  76         if (ret < 0 || (size_t)ret >= l)
  77                 return -1;
  78
  79         s[l - 2] = '/';
  80         s[l - 1] = '\0';
  81
  82         execlp("rsync", "rsync", "-aHXS", "--delete", s, dest, (char *)NULL);
  83         return -1;
  84 }
  85
  86 int lxc_rsync(struct rsync_data *data)
  87 {
  88         int ret;
  89         const char *dest, *src;
  90         struct lxc_storage *orig = data->orig, *new = data->new;
  91
  92         ret = unshare(CLONE_NEWNS);
  93         if (ret < 0) {
  94                 SYSERROR("Failed to unshare CLONE_NEWNS");
  95                 return -1;
  96         }
  97
  98         ret = detect_shared_rootfs();
  99         if (ret) {
 100                 ret = mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
 101                 if (ret < 0)
 102                         SYSERROR("Failed to make \"/\" a slave mount");
 103         }
 104
 105         ret = orig->ops->mount(orig);
 106         if (ret < 0) {
 107                 ERROR("Failed mounting \"%s\" on \"%s\"", orig->src, orig->dest);
 108                 return -1;
 109         }
 110
 111         ret = new->ops->mount(new);
 112         if (ret < 0) {
 113                 ERROR("Failed mounting \"%s\" onto \"%s\"", new->src, new->dest);
 114                 return -1;
 115         }
 116
 117         ret = lxc_switch_uid_gid(0, 0);
 118         if (ret < 0)
 119                 return -1;
 120
 121         ret = lxc_setgroups(0, NULL);
 122         if (ret < 0)
 123                 return -1;
 124
 125         src = lxc_storage_get_path(orig->dest, orig->type);
 126         dest = lxc_storage_get_path(new->dest, new->type);
 127
 128         ret = lxc_rsync_exec(src, dest);
 129         if (ret < 0) {
 130                 ERROR("Failed to rsync from \"%s\" into \"%s\"", src, dest);
 131                 return -1;
 132         }
 133
 134         return 0;
 135 }