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 #include "config.h"
  10
  11 #include <sys/types.h>
  12 #include <sys/stat.h>
  13 #include <unistd.h>
  14 #include <netinet/in.h>
  15 #include <arpa/inet.h>
  16 #include <netdb.h>
  17 #include "xmalloc.h"
  18 #include "misc.h"
  19 #include "exportfs.h"
  20 #include "xio.h"
  21 #include "mountd.h"
  22 #include "ha-callout.h"
  23
  24 #include <limits.h> /* PATH_MAX */
  25
  26 /* If new path is a link do not destroy it but place the
  27  * file where the link points.
  28  */
  29
  30 static int
  31 slink_safe_rename(const char * oldpath, const char * newpath)
  32 {
  33         int r;
  34         struct stat s;
  35         char slink_path[PATH_MAX];
  36         const char *real_newpath = newpath;
  37
  38         if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
  39                 /* New path is a symbolic link, do not destroy but follow */
  40                 if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
  41                         return -1;
  42                 slink_path[r] = '\0';
  43                 real_newpath = slink_path;
  44         }
  45
  46         return rename(oldpath, real_newpath);
  47 }
  48
  49 void
  50 mountlist_add(char *host, const char *path)
  51 {
  52         struct rmtabent xe;
  53         struct rmtabent *rep;
  54         int             lockid;
  55         long            pos;
  56
  57         if ((lockid = xflock(_PATH_RMTAB, "a")) < 0)
  58                 return;
  59         setrmtabent("r+");
  60         while ((rep = getrmtabent(1, &pos)) != NULL) {
  61                 if (strcmp (rep->r_client,
  62                             host) == 0
  63                     && strcmp(rep->r_path, path) == 0) {
  64                         rep->r_count++;
  65                         /* PRC: do the HA callout: */
  66                         ha_callout("mount", rep->r_client, rep->r_path, rep->r_count);
  67                         putrmtabent(rep, &pos);
  68                         endrmtabent();
  69                         xfunlock(lockid);
  70                         return;
  71                 }
  72         }
  73         endrmtabent();
  74         strncpy(xe.r_client, host,
  75                 sizeof (xe.r_client) - 1);
  76         xe.r_client [sizeof (xe.r_client) - 1] = '\0';
  77         strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
  78         xe.r_path [sizeof (xe.r_path) - 1] = '\0';
  79         xe.r_count = 1;
  80         if (setrmtabent("a")) {
  81                 /* PRC: do the HA callout: */
  82                 ha_callout("mount", xe.r_client, xe.r_path, xe.r_count);
  83                 putrmtabent(&xe, NULL);
  84                 endrmtabent();
  85         }
  86         xfunlock(lockid);
  87 }
  88
  89 void
  90 mountlist_del(char *hname, const char *path)
  91 {
  92         struct rmtabent *rep;
  93         FILE            *fp;
  94         int             lockid;
  95         int             match;
  96
  97         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
  98                 return;
  99         if (!setrmtabent("r")) {
 100                 xfunlock(lockid);
 101                 return;
 102         }
 103         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 104                 endrmtabent();
 105                 xfunlock(lockid);
 106                 return;
 107         }
 108         while ((rep = getrmtabent(1, NULL)) != NULL) {
 109                 match = !strcmp (rep->r_client, hname)
 110                         && !strcmp(rep->r_path, path);
 111                 if (match) {
 112                         rep->r_count--;
 113                         /* PRC: do the HA callout: */
 114                         ha_callout("unmount", rep->r_client, rep->r_path, rep->r_count);
 115                 }
 116                 if (!match || rep->r_count)
 117                         fputrmtabent(fp, rep, NULL);
 118         }
 119         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 120                 xlog(L_ERROR, "couldn't rename %s to %s",
 121                                 _PATH_RMTABTMP, _PATH_RMTAB);
 122         }
 123         endrmtabent();  /* close & unlink */
 124         fendrmtabent(fp);
 125         xfunlock(lockid);
 126 }
 127
 128 void
 129 mountlist_del_all(struct sockaddr_in *sin)
 130 {
 131         struct in_addr  addr = sin->sin_addr;
 132         struct hostent  *hp;
 133         struct rmtabent *rep;
 134         nfs_export      *exp;
 135         FILE            *fp;
 136         int             lockid;
 137
 138         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
 139                 return;
 140         if (!(hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET))) {
 141                 xlog(L_ERROR, "can't get hostname of %s", inet_ntoa(addr));
 142                 xfunlock(lockid);
 143                 return;
 144         }
 145         else
 146                 hp = hostent_dup (hp);
 147
 148         if (!setrmtabent("r")) {
 149                 xfunlock(lockid);
 150                 free (hp);
 151                 return;
 152         }
 153         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 154                 endrmtabent();
 155                 xfunlock(lockid);
 156                 free (hp);
 157                 return;
 158         }
 159         while ((rep = getrmtabent(1, NULL)) != NULL) {
 160                 if (strcmp(rep->r_client, hp->h_name) == 0 &&
 161                     (exp = auth_authenticate("umountall", sin, rep->r_path))) {
 162                         export_reset(exp);
 163                         continue;
 164                 }
 165                 fputrmtabent(fp, rep, NULL);
 166         }
 167         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 168                 xlog(L_ERROR, "couldn't rename %s to %s",
 169                                 _PATH_RMTABTMP, _PATH_RMTAB);
 170         }
 171         endrmtabent();  /* close & unlink */
 172         fendrmtabent(fp);
 173         xfunlock(lockid);
 174         free (hp);
 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
 187         if ((lockid = xflock(_PATH_RMTAB, "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                         m->ml_hostname = xstrdup(rep->r_client);
 206                         m->ml_directory = xstrdup(rep->r_path);
 207                         m->ml_next = mlist;
 208                         mlist = m;
 209                 }
 210                 endrmtabent();
 211         }
 212         xfunlock(lockid);
 213
 214         return mlist;
 215 }