src/lxc/storage/rsync.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #ifndef _GNU_SOURCE
   4 #define _GNU_SOURCE 1
   5 #endif
   6 #include <grp.h>
   7 #include <sched.h>
   8 #include <stdint.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <sys/mount.h>
  13 #include <sys/types.h>
  14 #include <unistd.h>
  15
  16 #include "config.h"
  17 #include "log.h"
  18 #include "rsync.h"
  19 #include "storage.h"
  20 #include "syscall_wrappers.h"
  21 #include "utils.h"
  22
  23 lxc_log_define(rsync, lxc);
  24
  25 int lxc_storage_rsync_exec_wrapper(void *data)
  26 {
  27         struct rsync_data *arg = data;
  28         return lxc_rsync(arg);
  29 }
  30
  31 int lxc_rsync_exec_wrapper(void *data)
  32 {
  33         struct rsync_data_char *args = data;
  34
  35         if (!lxc_switch_uid_gid(0, 0))
  36                 return -1;
  37
  38         if (!lxc_setgroups(0, NULL))
  39                 return -1;
  40
  41         return lxc_rsync_exec(args->src, args->dest);
  42 }
  43
  44 int lxc_rsync_exec(const char *src, const char *dest)
  45 {
  46         int ret;
  47         size_t l;
  48         char *s;
  49
  50         l = strlen(src) + 2;
  51         s = malloc(l);
  52         if (!s)
  53                 return -1;
  54
  55         ret = snprintf(s, l, "%s", src);
  56         if (ret < 0 || (size_t)ret >= l) {
  57                 free(s);
  58                 return -1;
  59         }
  60
  61         s[l - 2] = '/';
  62         s[l - 1] = '\0';
  63
  64         execlp("rsync", "rsync", "-aHXS", "--delete", s, dest, (char *)NULL);
  65         free(s);
  66         return -1;
  67 }
  68
  69 int lxc_rsync(struct rsync_data *data)
  70 {
  71         int ret;
  72         const char *dest, *src;
  73         struct lxc_storage *orig = data->orig, *new = data->new;
  74
  75         ret = unshare(CLONE_NEWNS);
  76         if (ret < 0) {
  77                 SYSERROR("Failed to unshare CLONE_NEWNS");
  78                 return -1;
  79         }
  80
  81         ret = detect_shared_rootfs();
  82         if (ret) {
  83                 ret = mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
  84                 if (ret < 0)
  85                         SYSERROR("Failed to make \"/\" a slave mount");
  86         }
  87
  88         ret = orig->ops->mount(orig);
  89         if (ret < 0) {
  90                 ERROR("Failed mounting \"%s\" on \"%s\"", orig->src, orig->dest);
  91                 return -1;
  92         }
  93
  94         ret = new->ops->mount(new);
  95         if (ret < 0) {
  96                 ERROR("Failed mounting \"%s\" onto \"%s\"", new->src, new->dest);
  97                 return -1;
  98         }
  99
 100         if (!lxc_switch_uid_gid(0, 0))
 101                 return -1;
 102
 103         if (!lxc_setgroups(0, NULL))
 104                 return -1;
 105
 106         src = lxc_storage_get_path(orig->dest, orig->type);
 107         dest = lxc_storage_get_path(new->dest, new->type);
 108
 109         ret = lxc_rsync_exec(src, dest);
 110         if (ret < 0) {
 111                 ERROR("Failed to rsync from \"%s\" into \"%s\"", src, dest);
 112                 return -1;
 113         }
 114
 115         return 0;
 116 }