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 extern int reverse_resolve;
  29
  30 /* If new path is a link do not destroy it but place the
  31  * file where the link points.
  32  */
  33
  34 static int
  35 slink_safe_rename(const char * oldpath, const char * newpath)
  36 {
  37         int r;
  38         struct stat s;
  39         char slink_path[PATH_MAX];
  40         const char *real_newpath = newpath;
  41
  42         if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
  43                 /* New path is a symbolic link, do not destroy but follow */
  44                 if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
  45                         return -1;
  46                 slink_path[r] = '\0';
  47                 real_newpath = slink_path;
  48         }
  49
  50         return rename(oldpath, real_newpath);
  51 }
  52
  53 void
  54 mountlist_add(char *host, const char *path)
  55 {
  56         struct rmtabent xe;
  57         struct rmtabent *rep;
  58         int             lockid;
  59         long            pos;
  60
  61         if ((lockid = xflock(_PATH_RMTABLCK, "a")) < 0)
  62                 return;
  63         setrmtabent("r+");
  64         while ((rep = getrmtabent(1, &pos)) != NULL) {
  65                 if (strcmp (rep->r_client,
  66                             host) == 0
  67                     && strcmp(rep->r_path, path) == 0) {
  68                         rep->r_count++;
  69                         /* PRC: do the HA callout: */
  70                         ha_callout("mount", rep->r_client, rep->r_path, rep->r_count);
  71                         putrmtabent(rep, &pos);
  72                         endrmtabent();
  73                         xfunlock(lockid);
  74                         return;
  75                 }
  76         }
  77         endrmtabent();
  78         strncpy(xe.r_client, host,
  79                 sizeof (xe.r_client) - 1);
  80         xe.r_client [sizeof (xe.r_client) - 1] = '\0';
  81         strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
  82         xe.r_path [sizeof (xe.r_path) - 1] = '\0';
  83         xe.r_count = 1;
  84         if (setrmtabent("a")) {
  85                 /* PRC: do the HA callout: */
  86                 ha_callout("mount", xe.r_client, xe.r_path, xe.r_count);
  87                 putrmtabent(&xe, NULL);
  88                 endrmtabent();
  89         }
  90         xfunlock(lockid);
  91 }
  92
  93 void
  94 mountlist_del(char *hname, const char *path)
  95 {
  96         struct rmtabent *rep;
  97         FILE            *fp;
  98         int             lockid;
  99         int             match;
 100
 101         if ((lockid = xflock(_PATH_RMTABLCK, "w")) < 0)
 102                 return;
 103         if (!setrmtabent("r")) {
 104                 xfunlock(lockid);
 105                 return;
 106         }
 107         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 108                 endrmtabent();
 109                 xfunlock(lockid);
 110                 return;
 111         }
 112         while ((rep = getrmtabent(1, NULL)) != NULL) {
 113                 match = !strcmp (rep->r_client, hname)
 114                         && !strcmp(rep->r_path, path);
 115                 if (match) {
 116                         rep->r_count--;
 117                         /* PRC: do the HA callout: */
 118                         ha_callout("unmount", rep->r_client, rep->r_path, rep->r_count);
 119                 }
 120                 if (!match || rep->r_count)
 121                         fputrmtabent(fp, rep, NULL);
 122         }
 123         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 124                 xlog(L_ERROR, "couldn't rename %s to %s",
 125                                 _PATH_RMTABTMP, _PATH_RMTAB);
 126         }
 127         endrmtabent();  /* close & unlink */
 128         fendrmtabent(fp);
 129         xfunlock(lockid);
 130 }
 131
 132 void
 133 mountlist_del_all(struct sockaddr_in *sin)
 134 {
 135         struct in_addr  addr = sin->sin_addr;
 136         struct hostent  *hp;
 137         struct rmtabent *rep;
 138         nfs_export      *exp;
 139         FILE            *fp;
 140         int             lockid;
 141
 142         if ((lockid = xflock(_PATH_RMTABLCK, "w")) < 0)
 143                 return;
 144         if (!(hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET))) {
 145                 xlog(L_ERROR, "can't get hostname of %s", inet_ntoa(addr));
 146                 goto out_unlock;
 147         }
 148         hp = hostent_dup (hp);
 149
 150         if (!setrmtabent("r"))
 151                 goto out_free;
 152
 153         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w")))
 154                 goto out_close;
 155
 156         while ((rep = getrmtabent(1, NULL)) != NULL) {
 157                 if (strcmp(rep->r_client, hp->h_name) == 0 &&
 158                     (exp = auth_authenticate("umountall", sin, rep->r_path)))
 159                         continue;
 160                 fputrmtabent(fp, rep, NULL);
 161         }
 162         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 163                 xlog(L_ERROR, "couldn't rename %s to %s",
 164                                 _PATH_RMTABTMP, _PATH_RMTAB);
 165         }
 166         fendrmtabent(fp);
 167 out_close:
 168         endrmtabent();  /* close & unlink */
 169 out_free:
 170         free (hp);
 171 out_unlock:
 172         xfunlock(lockid);
 173 }
 174
 175 mountlist
 176 mountlist_list(void)
 177 {
 178         static mountlist        mlist = NULL;
 179         static time_t           last_mtime = 0;
 180         mountlist               m;
 181         struct rmtabent         *rep;
 182         struct stat             stb;
 183         int                     lockid;
 184         struct in_addr          addr;
 185         struct hostent          *he;
 186
 187         if ((lockid = xflock(_PATH_RMTABLCK, "r")) < 0)
 188                 return NULL;
 189         if (stat(_PATH_RMTAB, &stb) < 0) {
 190                 xlog(L_ERROR, "can't stat %s", _PATH_RMTAB);
 191                 return NULL;
 192         }
 193         if (stb.st_mtime != last_mtime) {
 194                 while (mlist) {
 195                         mlist = (m = mlist)->ml_next;
 196                         xfree(m->ml_hostname);
 197                         xfree(m->ml_directory);
 198                         xfree(m);
 199                 }
 200                 last_mtime = stb.st_mtime;
 201
 202                 setrmtabent("r");
 203                 while ((rep = getrmtabent(1, NULL)) != NULL) {
 204                         m = (mountlist) xmalloc(sizeof(*m));
 205
 206                         if (reverse_resolve &&
 207                            inet_aton((const char *) rep->r_client, &addr) &&
 208                            (he = gethostbyaddr(&addr, sizeof(addr), AF_INET)))
 209                                 m->ml_hostname = xstrdup(he->h_name);
 210                         else
 211                                 m->ml_hostname = xstrdup(rep->r_client);
 212
 213                         m->ml_directory = xstrdup(rep->r_path);
 214                         m->ml_next = mlist;
 215                         mlist = m;
 216                 }
 217                 endrmtabent();
 218         }
 219         xfunlock(lockid);
 220
 221         return mlist;
 222 }