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 #include "xmalloc.h"
  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
  28 /* If new path is a link do not destroy it but place the
  29  * file where the link points.
  30  */
  31
  32 static int
  33 slink_safe_rename(const char * oldpath, const char * newpath)
  34 {
  35         int r;
  36         struct stat s;
  37         char slink_path[PATH_MAX];
  38         const char *real_newpath = newpath;
  39
  40         if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
  41                 /* New path is a symbolic link, do not destroy but follow */
  42                 if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
  43                         return -1;
  44                 slink_path[r] = '\0';
  45                 real_newpath = slink_path;
  46         }
  47
  48         return rename(oldpath, real_newpath);
  49 }
  50
  51 void
  52 mountlist_add(char *host, const char *path)
  53 {
  54         struct rmtabent xe;
  55         struct rmtabent *rep;
  56         int             lockid;
  57         long            pos;
  58
  59         if ((lockid = xflock(_PATH_RMTAB, "a")) < 0)
  60                 return;
  61         setrmtabent("r+");
  62         while ((rep = getrmtabent(1, &pos)) != NULL) {
  63                 if (strcmp (rep->r_client,
  64                             host) == 0
  65                     && strcmp(rep->r_path, path) == 0) {
  66                         rep->r_count++;
  67                         /* PRC: do the HA callout: */
  68                         ha_callout("mount", rep->r_client, rep->r_path, rep->r_count);
  69                         putrmtabent(rep, &pos);
  70                         endrmtabent();
  71                         xfunlock(lockid);
  72                         return;
  73                 }
  74         }
  75         endrmtabent();
  76         strncpy(xe.r_client, host,
  77                 sizeof (xe.r_client) - 1);
  78         xe.r_client [sizeof (xe.r_client) - 1] = '\0';
  79         strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
  80         xe.r_path [sizeof (xe.r_path) - 1] = '\0';
  81         xe.r_count = 1;
  82         if (setrmtabent("a")) {
  83                 /* PRC: do the HA callout: */
  84                 ha_callout("mount", xe.r_client, xe.r_path, xe.r_count);
  85                 putrmtabent(&xe, NULL);
  86                 endrmtabent();
  87         }
  88         xfunlock(lockid);
  89 }
  90
  91 void
  92 mountlist_del(char *hname, const char *path)
  93 {
  94         struct rmtabent *rep;
  95         FILE            *fp;
  96         int             lockid;
  97         int             match;
  98
  99         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
 100                 return;
 101         if (!setrmtabent("r")) {
 102                 xfunlock(lockid);
 103                 return;
 104         }
 105         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 106                 endrmtabent();
 107                 xfunlock(lockid);
 108                 return;
 109         }
 110         while ((rep = getrmtabent(1, NULL)) != NULL) {
 111                 match = !strcmp (rep->r_client, hname)
 112                         && !strcmp(rep->r_path, path);
 113                 if (match) {
 114                         rep->r_count--;
 115                         /* PRC: do the HA callout: */
 116                         ha_callout("unmount", rep->r_client, rep->r_path, rep->r_count);
 117                 }
 118                 if (!match || rep->r_count)
 119                         fputrmtabent(fp, rep, NULL);
 120         }
 121         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 122                 xlog(L_ERROR, "couldn't rename %s to %s",
 123                                 _PATH_RMTABTMP, _PATH_RMTAB);
 124         }
 125         endrmtabent();  /* close & unlink */
 126         fendrmtabent(fp);
 127         xfunlock(lockid);
 128 }
 129
 130 void
 131 mountlist_del_all(struct sockaddr_in *sin)
 132 {
 133         struct in_addr  addr = sin->sin_addr;
 134         struct hostent  *hp;
 135         struct rmtabent *rep;
 136         nfs_export      *exp;
 137         FILE            *fp;
 138         int             lockid;
 139
 140         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
 141                 return;
 142         if (!(hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET))) {
 143                 xlog(L_ERROR, "can't get hostname of %s", inet_ntoa(addr));
 144                 xfunlock(lockid);
 145                 return;
 146         }
 147         else
 148                 hp = hostent_dup (hp);
 149
 150         if (!setrmtabent("r")) {
 151                 xfunlock(lockid);
 152                 free (hp);
 153                 return;
 154         }
 155         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 156                 endrmtabent();
 157                 xfunlock(lockid);
 158                 free (hp);
 159                 return;
 160         }
 161         while ((rep = getrmtabent(1, NULL)) != NULL) {
 162                 if (strcmp(rep->r_client, hp->h_name) == 0 &&
 163                     (exp = auth_authenticate("umountall", sin, rep->r_path))) {
 164                         export_reset(exp);
 165                         continue;
 166                 }
 167                 fputrmtabent(fp, rep, NULL);
 168         }
 169         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 170                 xlog(L_ERROR, "couldn't rename %s to %s",
 171                                 _PATH_RMTABTMP, _PATH_RMTAB);
 172         }
 173         endrmtabent();  /* close & unlink */
 174         fendrmtabent(fp);
 175         xfunlock(lockid);
 176         free (hp);
 177 }
 178
 179 mountlist
 180 mountlist_list(void)
 181 {
 182         static mountlist        mlist = NULL;
 183         static time_t           last_mtime = 0;
 184         mountlist               m;
 185         struct rmtabent         *rep;
 186         struct stat             stb;
 187         int                     lockid;
 188
 189         if ((lockid = xflock(_PATH_RMTAB, "r")) < 0)
 190                 return NULL;
 191         if (stat(_PATH_RMTAB, &stb) < 0) {
 192                 xlog(L_ERROR, "can't stat %s", _PATH_RMTAB);
 193                 return NULL;
 194         }
 195         if (stb.st_mtime != last_mtime) {
 196                 while (mlist) {
 197                         mlist = (m = mlist)->ml_next;
 198                         xfree(m->ml_hostname);
 199                         xfree(m->ml_directory);
 200                         xfree(m);
 201                 }
 202                 last_mtime = stb.st_mtime;
 203
 204                 setrmtabent("r");
 205                 while ((rep = getrmtabent(1, NULL)) != NULL) {
 206                         m = (mountlist) xmalloc(sizeof(*m));
 207                         m->ml_hostname = xstrdup(rep->r_client);
 208                         m->ml_directory = xstrdup(rep->r_path);
 209                         m->ml_next = mlist;
 210                         mlist = m;
 211                 }
 212                 endrmtabent();
 213         }
 214         xfunlock(lockid);
 215
 216         return mlist;
 217 }