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 #ifndef _GNU_SOURCE
  25 #define _GNU_SOURCE 1
  26 #endif
  27 #include <grp.h>
  28 #include <sched.h>
  29 #include <stdint.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <sys/mount.h>
  34 #include <sys/types.h>
  35 #include <unistd.h>
  36
  37 #include "config.h"
  38 #include "log.h"
  39 #include "rsync.h"
  40 #include "storage.h"
  41 #include "syscall_wrappers.h"
  42 #include "utils.h"
  43
  44 lxc_log_define(rsync, lxc);
  45
  46 int lxc_storage_rsync_exec_wrapper(void *data)
  47 {
  48         struct rsync_data *arg = data;
  49         return lxc_rsync(arg);
  50 }
  51
  52 int lxc_rsync_exec_wrapper(void *data)
  53 {
  54         struct rsync_data_char *args = data;
  55
  56         if (!lxc_switch_uid_gid(0, 0))
  57                 return -1;
  58
  59         if (!lxc_setgroups(0, NULL))
  60                 return -1;
  61
  62         return lxc_rsync_exec(args->src, args->dest);
  63 }
  64
  65 int lxc_rsync_exec(const char *src, const char *dest)
  66 {
  67         int ret;
  68         size_t l;
  69         char *s;
  70
  71         l = strlen(src) + 2;
  72         s = malloc(l);
  73         if (!s)
  74                 return -1;
  75
  76         ret = snprintf(s, l, "%s", src);
  77         if (ret < 0 || (size_t)ret >= l) {
  78                 free(s);
  79                 return -1;
  80         }
  81
  82         s[l - 2] = '/';
  83         s[l - 1] = '\0';
  84
  85         execlp("rsync", "rsync", "-aHXS", "--delete", s, dest, (char *)NULL);
  86         free(s);
  87         return -1;
  88 }
  89
  90 int lxc_rsync(struct rsync_data *data)
  91 {
  92         int ret;
  93         const char *dest, *src;
  94         struct lxc_storage *orig = data->orig, *new = data->new;
  95
  96         ret = unshare(CLONE_NEWNS);
  97         if (ret < 0) {
  98                 SYSERROR("Failed to unshare CLONE_NEWNS");
  99                 return -1;
 100         }
 101
 102         ret = detect_shared_rootfs();
 103         if (ret) {
 104                 ret = mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
 105                 if (ret < 0)
 106                         SYSERROR("Failed to make \"/\" a slave mount");
 107         }
 108
 109         ret = orig->ops->mount(orig);
 110         if (ret < 0) {
 111                 ERROR("Failed mounting \"%s\" on \"%s\"", orig->src, orig->dest);
 112                 return -1;
 113         }
 114
 115         ret = new->ops->mount(new);
 116         if (ret < 0) {
 117                 ERROR("Failed mounting \"%s\" onto \"%s\"", new->src, new->dest);
 118                 return -1;
 119         }
 120
 121         if (!lxc_switch_uid_gid(0, 0))
 122                 return -1;
 123
 124         if (!lxc_setgroups(0, NULL))
 125                 return -1;
 126
 127         src = lxc_storage_get_path(orig->dest, orig->type);
 128         dest = lxc_storage_get_path(new->dest, new->type);
 129
 130         ret = lxc_rsync_exec(src, dest);
 131         if (ret < 0) {
 132                 ERROR("Failed to rsync from \"%s\" into \"%s\"", src, dest);
 133                 return -1;
 134         }
 135
 136         return 0;
 137 }