utils/mountd/rmtab.c

   1 /*
   2  * utils/mountd/rmtab.c
   3  *
   4  * Manage the rmtab file for mountd.
   5  *
   6  * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
   7  */
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include <config.h>
  11 #endif
  12
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15 #include <unistd.h>
  16 #include <netinet/in.h>
  17 #include <arpa/inet.h>
  18 #include <netdb.h>
  19
  20 #include "misc.h"
  21 #include "exportfs.h"
  22 #include "xio.h"
  23 #include "mountd.h"
  24 #include "ha-callout.h"
  25
  26 #include <limits.h> /* PATH_MAX */
  27 #include <errno.h>
  28
  29 extern int reverse_resolve;
  30
  31 /* If new path is a link do not destroy it but place the
  32  * file where the link points.
  33  */
  34
  35 static int
  36 slink_safe_rename(const char * oldpath, const char * newpath)
  37 {
  38         int r;
  39         struct stat s;
  40         char slink_path[PATH_MAX];
  41         const char *real_newpath = newpath;
  42
  43         if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
  44                 /* New path is a symbolic link, do not destroy but follow */
  45                 if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
  46                         return -1;
  47                 slink_path[r] = '\0';
  48                 real_newpath = slink_path;
  49         }
  50
  51         return rename(oldpath, real_newpath);
  52 }
  53
  54 void
  55 mountlist_add(char *host, const char *path)
  56 {
  57         struct rmtabent xe;
  58         struct rmtabent *rep;
  59         int             lockid;
  60         long            pos;
  61
  62         if ((lockid = xflock(_PATH_RMTABLCK, "a")) < 0)
  63                 return;
  64         setrmtabent("r+");
  65         while ((rep = getrmtabent(1, &pos)) != NULL) {
  66                 if (strcmp (rep->r_client,
  67                             host) == 0
  68                     && strcmp(rep->r_path, path) == 0) {
  69                         rep->r_count++;
  70                         /* PRC: do the HA callout: */
  71                         ha_callout("mount", rep->r_client, rep->r_path, rep->r_count);
  72                         putrmtabent(rep, &pos);
  73                         endrmtabent();
  74                         xfunlock(lockid);
  75                         return;
  76                 }
  77         }
  78         endrmtabent();
  79         strncpy(xe.r_client, host,
  80                 sizeof (xe.r_client) - 1);
  81         xe.r_client [sizeof (xe.r_client) - 1] = '\0';
  82         strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
  83         xe.r_path [sizeof (xe.r_path) - 1] = '\0';
  84         xe.r_count = 1;
  85         if (setrmtabent("a")) {
  86                 /* PRC: do the HA callout: */
  87                 ha_callout("mount", xe.r_client, xe.r_path, xe.r_count);
  88                 putrmtabent(&xe, NULL);
  89                 endrmtabent();
  90         }
  91         xfunlock(lockid);
  92 }
  93
  94 void
  95 mountlist_del(char *hname, const char *path)
  96 {
  97         struct rmtabent *rep;
  98         FILE            *fp;
  99         int             lockid;
 100         int             match;
 101
 102         if ((lockid = xflock(_PATH_RMTABLCK, "w")) < 0)
 103                 return;
 104         if (!setrmtabent("r")) {
 105                 xfunlock(lockid);
 106                 return;
 107         }
 108         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 109                 endrmtabent();
 110                 xfunlock(lockid);
 111                 return;
 112         }
 113         while ((rep = getrmtabent(1, NULL)) != NULL) {
 114                 match = !strcmp (rep->r_client, hname)
 115                         && !strcmp(rep->r_path, path);
 116                 if (match) {
 117                         rep->r_count--;
 118                         /* PRC: do the HA callout: */
 119                         ha_callout("unmount", rep->r_client, rep->r_path, rep->r_count);
 120                 }
 121                 if (!match || rep->r_count)
 122                         fputrmtabent(fp, rep, NULL);
 123         }
 124         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 125                 xlog(L_ERROR, "couldn't rename %s to %s",
 126                                 _PATH_RMTABTMP, _PATH_RMTAB);
 127         }
 128         endrmtabent();  /* close & unlink */
 129         fendrmtabent(fp);
 130         xfunlock(lockid);
 131 }
 132
 133 void
 134 mountlist_del_all(const struct sockaddr *sap)
 135 {
 136         char            *hostname;
 137         struct rmtabent *rep;
 138         FILE            *fp;
 139         int             lockid;
 140
 141         if ((lockid = xflock(_PATH_RMTABLCK, "w")) < 0)
 142                 return;
 143         hostname = host_canonname(sap);
 144         if (hostname == NULL) {
 145                 char buf[INET6_ADDRSTRLEN];
 146                 xlog(L_ERROR, "can't get hostname of %s",
 147                         host_ntop(sap, buf, sizeof(buf)));
 148                 goto out_unlock;
 149         }
 150
 151         if (!setrmtabent("r"))
 152                 goto out_free;
 153
 154         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w")))
 155                 goto out_close;
 156
 157         while ((rep = getrmtabent(1, NULL)) != NULL) {
 158                 if (strcmp(rep->r_client, hostname) == 0 &&
 159                     auth_authenticate("umountall", sap, rep->r_path) != NULL)
 160                         continue;
 161                 fputrmtabent(fp, rep, NULL);
 162         }
 163         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 164                 xlog(L_ERROR, "couldn't rename %s to %s",
 165                                 _PATH_RMTABTMP, _PATH_RMTAB);
 166         }
 167         fendrmtabent(fp);
 168 out_close:
 169         endrmtabent();  /* close & unlink */
 170 out_free:
 171         free(hostname);
 172 out_unlock:
 173         xfunlock(lockid);
 174 }
 175
 176 static void
 177 mountlist_freeall(mountlist list)
 178 {
 179         while (list != NULL) {
 180                 mountlist m = list;
 181                 list = m->ml_next;
 182                 free(m->ml_hostname);
 183                 free(m->ml_directory);
 184                 free(m);
 185         }
 186 }
 187
 188 mountlist
 189 mountlist_list(void)
 190 {
 191         static mountlist        mlist = NULL;
 192         static time_t           last_mtime = 0;
 193         mountlist               m;
 194         struct rmtabent         *rep;
 195         struct stat             stb;
 196         int                     lockid;
 197
 198         if ((lockid = xflock(_PATH_RMTABLCK, "r")) < 0)
 199                 return NULL;
 200         if (stat(_PATH_RMTAB, &stb) < 0) {
 201                 xlog(L_ERROR, "can't stat %s: %s",
 202                                 _PATH_RMTAB, strerror(errno));
 203                 xfunlock(lockid);
 204                 return NULL;
 205         }
 206         if (stb.st_mtime != last_mtime) {
 207                 mountlist_freeall(mlist);
 208                 mlist = NULL;
 209                 last_mtime = stb.st_mtime;
 210
 211                 setrmtabent("r");
 212                 while ((rep = getrmtabent(1, NULL)) != NULL) {
 213                         m = calloc(1, sizeof(*m));
 214                         if (m == NULL) {
 215                                 mountlist_freeall(mlist);
 216                                 mlist = NULL;
 217                                 xlog(L_ERROR, "%s: memory allocation failed",
 218                                                 __func__);
 219                                 break;
 220                         }
 221
 222                         if (reverse_resolve) {
 223                                 struct addrinfo *ai;
 224                                 ai = host_pton(rep->r_client);
 225                                 if (ai != NULL) {
 226                                         m->ml_hostname = host_canonname(ai->ai_addr);
 227                                         freeaddrinfo(ai);
 228                                 }
 229                         }
 230                         if (m->ml_hostname == NULL)
 231                                 m->ml_hostname = strdup(rep->r_client);
 232
 233                         m->ml_directory = strdup(rep->r_path);
 234
 235                         if (m->ml_hostname == NULL || m->ml_directory == NULL) {
 236                                 mountlist_freeall(mlist);
 237                                 mlist = NULL;
 238                                 xlog(L_ERROR, "%s: memory allocation failed",
 239                                                 __func__);
 240                                 break;
 241                         }
 242
 243                         m->ml_next = mlist;
 244                         mlist = m;
 245                 }
 246                 endrmtabent();
 247         }
 248         xfunlock(lockid);
 249
 250         return mlist;
 251 }