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 #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(struct sockaddr_in *sin)
 135 {
 136         char            *hostname;
 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         hostname = host_canonname((struct sockaddr *)sin);
 145         if (hostname == NULL) {
 146                 char buf[INET_ADDRSTRLEN];
 147                 xlog(L_ERROR, "can't get hostname of %s",
 148                         host_ntop((struct sockaddr *)sin, buf, sizeof(buf)));
 149                 goto out_unlock;
 150         }
 151
 152         if (!setrmtabent("r"))
 153                 goto out_free;
 154
 155         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w")))
 156                 goto out_close;
 157
 158         while ((rep = getrmtabent(1, NULL)) != NULL) {
 159                 if (strcmp(rep->r_client, hostname) == 0 &&
 160                     (exp = auth_authenticate("umountall", sin, rep->r_path)))
 161                         continue;
 162                 fputrmtabent(fp, rep, NULL);
 163         }
 164         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 165                 xlog(L_ERROR, "couldn't rename %s to %s",
 166                                 _PATH_RMTABTMP, _PATH_RMTAB);
 167         }
 168         fendrmtabent(fp);
 169 out_close:
 170         endrmtabent();  /* close & unlink */
 171 out_free:
 172         free(hostname);
 173 out_unlock:
 174         xfunlock(lockid);
 175 }
 176
 177 mountlist
 178 mountlist_list(void)
 179 {
 180         static mountlist        mlist = NULL;
 181         static time_t           last_mtime = 0;
 182         mountlist               m;
 183         struct rmtabent         *rep;
 184         struct stat             stb;
 185         int                     lockid;
 186         struct in_addr          addr;
 187         struct hostent          *he;
 188
 189         if ((lockid = xflock(_PATH_RMTABLCK, "r")) < 0)
 190                 return NULL;
 191         if (stat(_PATH_RMTAB, &stb) < 0) {
 192                 xlog(L_ERROR, "can't stat %s: %s",
 193                                 _PATH_RMTAB, strerror(errno));
 194                 xfunlock(lockid);
 195                 return NULL;
 196         }
 197         if (stb.st_mtime != last_mtime) {
 198                 while (mlist) {
 199                         mlist = (m = mlist)->ml_next;
 200                         xfree(m->ml_hostname);
 201                         xfree(m->ml_directory);
 202                         xfree(m);
 203                 }
 204                 last_mtime = stb.st_mtime;
 205
 206                 setrmtabent("r");
 207                 while ((rep = getrmtabent(1, NULL)) != NULL) {
 208                         m = (mountlist) xmalloc(sizeof(*m));
 209
 210                         if (reverse_resolve &&
 211                            inet_aton((const char *) rep->r_client, &addr) &&
 212                            (he = gethostbyaddr(&addr, sizeof(addr), AF_INET)))
 213                                 m->ml_hostname = xstrdup(he->h_name);
 214                         else
 215                                 m->ml_hostname = xstrdup(rep->r_client);
 216
 217                         m->ml_directory = xstrdup(rep->r_path);
 218                         m->ml_next = mlist;
 219                         mlist = m;
 220                 }
 221                 endrmtabent();
 222         }
 223         xfunlock(lockid);
 224
 225         return mlist;
 226 }