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
  23 #include <limits.h> /* PATH_MAX */
  24
  25 /* If new path is a link do not destroy it but place the
  26  * file where the link points.
  27  */
  28
  29 static int
  30 slink_safe_rename(const char * oldpath, const char * newpath)
  31 {
  32         int r;
  33         struct stat s;
  34         char slink_path[PATH_MAX];
  35         const char *real_newpath = newpath;
  36
  37         if ((lstat(newpath, &s) == 0) && S_ISLNK(s.st_mode)) {
  38                 /* New path is a symbolic link, do not destroy but follow */
  39                 if ((r = readlink(newpath, slink_path, PATH_MAX - 1)) == -1)
  40                         return -1;
  41                 slink_path[r] = '\0';
  42                 real_newpath = slink_path;
  43         }
  44
  45         return rename(oldpath, real_newpath);
  46 }
  47
  48 void
  49 mountlist_add(nfs_export *exp, const char *path)
  50 {
  51         struct rmtabent xe;
  52         struct rmtabent *rep;
  53         int             lockid;
  54         long            pos;
  55
  56         if ((lockid = xflock(_PATH_RMTAB, "a")) < 0)
  57                 return;
  58         setrmtabent("r+");
  59         while ((rep = getrmtabent(1, &pos)) != NULL) {
  60                 if (strcmp (rep->r_client,
  61                             exp->m_client->m_hostname) == 0
  62                     && strcmp(rep->r_path, path) == 0) {
  63                         rep->r_count++;
  64                         putrmtabent(rep, &pos);
  65                         endrmtabent();
  66                         xfunlock(lockid);
  67                         return;
  68                 }
  69         }
  70         endrmtabent();
  71         strncpy(xe.r_client, exp->m_client->m_hostname,
  72                 sizeof (xe.r_client) - 1);
  73         xe.r_client [sizeof (xe.r_client) - 1] = '\0';
  74         strncpy(xe.r_path, path, sizeof (xe.r_path) - 1);
  75         xe.r_path [sizeof (xe.r_path) - 1] = '\0';
  76         xe.r_count = 1;
  77         if (setrmtabent("a")) {
  78                 putrmtabent(&xe, NULL);
  79                 endrmtabent();
  80         }
  81         xfunlock(lockid);
  82 }
  83
  84 void
  85 mountlist_del(nfs_export *exp, const char *path)
  86 {
  87         struct rmtabent *rep;
  88         FILE            *fp;
  89         char            *hname = exp->m_client->m_hostname;
  90         int             lockid;
  91         int             match;
  92
  93         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
  94                 return;
  95         if (!setrmtabent("r")) {
  96                 xfunlock(lockid);
  97                 return;
  98         }
  99         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 100                 endrmtabent();
 101                 xfunlock(lockid);
 102                 return;
 103         }
 104         while ((rep = getrmtabent(1, NULL)) != NULL) {
 105                 match = !strcmp (rep->r_client, hname)
 106                         && !strcmp(rep->r_path, path);
 107                 if (match)
 108                         rep->r_count--;
 109                 if (!match || rep->r_count)
 110                         fputrmtabent(fp, rep, NULL);
 111         }
 112         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 113                 xlog(L_ERROR, "couldn't rename %s to %s",
 114                                 _PATH_RMTABTMP, _PATH_RMTAB);
 115         }
 116         endrmtabent();  /* close & unlink */
 117         fendrmtabent(fp);
 118         xfunlock(lockid);
 119 }
 120
 121 void
 122 mountlist_del_all(struct sockaddr_in *sin)
 123 {
 124         struct in_addr  addr = sin->sin_addr;
 125         struct hostent  *hp;
 126         struct rmtabent *rep;
 127         nfs_export      *exp;
 128         FILE            *fp;
 129         int             lockid;
 130
 131         if ((lockid = xflock(_PATH_RMTAB, "w")) < 0)
 132                 return;
 133         if (!(hp = gethostbyaddr((char *)&addr, sizeof(addr), AF_INET))) {
 134                 xlog(L_ERROR, "can't get hostname of %s", inet_ntoa(addr));
 135                 xfunlock(lockid);
 136                 return;
 137         }
 138         else
 139                 hp = hostent_dup (hp);
 140
 141         if (!setrmtabent("r")) {
 142                 xfunlock(lockid);
 143                 free (hp);
 144                 return;
 145         }
 146         if (!(fp = fsetrmtabent(_PATH_RMTABTMP, "w"))) {
 147                 endrmtabent();
 148                 xfunlock(lockid);
 149                 free (hp);
 150                 return;
 151         }
 152         while ((rep = getrmtabent(1, NULL)) != NULL) {
 153                 if (strcmp(rep->r_client, hp->h_name) == 0 &&
 154                     (exp = auth_authenticate("umountall", sin, rep->r_path))) {
 155                         export_reset(exp);
 156                         continue;
 157                 }
 158                 fputrmtabent(fp, rep, NULL);
 159         }
 160         if (slink_safe_rename(_PATH_RMTABTMP, _PATH_RMTAB) < 0) {
 161                 xlog(L_ERROR, "couldn't rename %s to %s",
 162                                 _PATH_RMTABTMP, _PATH_RMTAB);
 163         }
 164         endrmtabent();  /* close & unlink */
 165         fendrmtabent(fp);
 166         xfunlock(lockid);
 167         free (hp);
 168 }
 169
 170 mountlist
 171 mountlist_list(void)
 172 {
 173         static mountlist        mlist = NULL;
 174         static time_t           last_mtime = 0;
 175         mountlist               m;
 176         struct rmtabent         *rep;
 177         struct stat             stb;
 178         int                     lockid;
 179
 180         if ((lockid = xflock(_PATH_RMTAB, "r")) < 0)
 181                 return NULL;
 182         if (stat(_PATH_RMTAB, &stb) < 0) {
 183                 xlog(L_ERROR, "can't stat %s", _PATH_RMTAB);
 184                 return NULL;
 185         }
 186         if (stb.st_mtime != last_mtime) {
 187                 while (mlist) {
 188                         mlist = (m = mlist)->ml_next;
 189                         xfree(m->ml_hostname);
 190                         xfree(m->ml_directory);
 191                         xfree(m);
 192                 }
 193                 last_mtime = stb.st_mtime;
 194
 195                 setrmtabent("r");
 196                 while ((rep = getrmtabent(1, NULL)) != NULL) {
 197                         m = (mountlist) xmalloc(sizeof(*m));
 198                         m->ml_hostname = xstrdup(rep->r_client);
 199                         m->ml_directory = xstrdup(rep->r_path);
 200                         m->ml_next = mlist;
 201                         mlist = m;
 202                 }
 203                 endrmtabent();
 204         }
 205         xfunlock(lockid);
 206
 207         return mlist;
 208 }