utils/mountd/auth.c

   1 /*
   2  * utils/mountd/auth.c
   3  *
   4  * Authentication procedures 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/stat.h>
  14 #include <netinet/in.h>
  15 #include <arpa/inet.h>
  16 #include <errno.h>
  17 #include <unistd.h>
  18 #include "misc.h"
  19 #include "nfslib.h"
  20 #include "exportfs.h"
  21 #include "mountd.h"
  22 #include "xmalloc.h"
  23
  24 enum auth_error
  25 {
  26   bad_path,
  27   unknown_host,
  28   no_entry,
  29   not_exported,
  30   illegal_port,
  31   success
  32 };
  33
  34 static void             auth_fixpath(char *path);
  35 static char     *export_file = NULL;
  36 static nfs_export my_exp;
  37 static nfs_client my_client;
  38
  39 extern int new_cache;
  40
  41 void
  42 auth_init(char *exports)
  43 {
  44
  45         export_file = exports;
  46         auth_reload();
  47         xtab_mount_write();
  48 }
  49
  50 unsigned int
  51 auth_reload()
  52 {
  53         struct stat             stb;
  54         static ino_t            last_inode;
  55         static int              last_fd;
  56         static unsigned int     counter;
  57         int                     fd;
  58
  59         if ((fd = open(_PATH_ETAB, O_RDONLY)) < 0) {
  60                 xlog(L_FATAL, "couldn't open %s", _PATH_ETAB);
  61         } else if (fstat(fd, &stb) < 0) {
  62                 xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB);
  63         } else if (stb.st_ino == last_inode) {
  64                 close(fd);
  65                 return counter;
  66         } else {
  67                 close(last_fd);
  68                 last_fd = fd;
  69                 last_inode = stb.st_ino;
  70         }
  71
  72         export_freeall();
  73         memset(&my_client, 0, sizeof(my_client));
  74         xtab_export_read();
  75         ++counter;
  76
  77         return counter;
  78 }
  79
  80 static nfs_export *
  81 auth_authenticate_internal(char *what, struct sockaddr_in *caller,
  82                            char *path, struct hostent *hp,
  83                            enum auth_error *error)
  84 {
  85         nfs_export              *exp;
  86
  87         if (new_cache) {
  88                 int i;
  89                 /* return static nfs_export with details filled in */
  90                 char *n;
  91                 my_client.m_addrlist[0] = caller->sin_addr;
  92                 n = client_compose(hp);
  93                 *error = unknown_host;
  94                 if (!n)
  95                         return NULL;
  96                 free(my_client.m_hostname);
  97                 if (*n) {
  98                         my_client.m_hostname = n;
  99                 } else {
 100                         free(n);
 101                         my_client.m_hostname = xstrdup("DEFAULT");
 102                 }
 103                 my_client.m_naddr = 1;
 104                 my_exp.m_client = &my_client;
 105
 106                 exp = NULL;
 107                 for (i = 0; !exp && i < MCL_MAXTYPES; i++)
 108                         for (exp = exportlist[i]; exp; exp = exp->m_next) {
 109                                 if (!client_member(my_client.m_hostname, exp->m_client->m_hostname))
 110                                         continue;
 111                                 if (strcmp(path, exp->m_export.e_path))
 112                                         continue;
 113                                 break;
 114                         }
 115                 *error = not_exported;
 116                 if (!exp)
 117                         return exp;
 118
 119                 my_exp.m_export = exp->m_export;
 120                 exp = &my_exp;
 121
 122         } else {
 123                 if (!(exp = export_find(hp, path))) {
 124                         *error = no_entry;
 125                         return NULL;
 126                 }
 127                 if (!exp->m_mayexport) {
 128                         *error = not_exported;
 129                         return NULL;
 130                 }
 131         }
 132         if (!(exp->m_export.e_flags & NFSEXP_INSECURE_PORT) &&
 133                     (ntohs(caller->sin_port) <  IPPORT_RESERVED/2 ||
 134                      ntohs(caller->sin_port) >= IPPORT_RESERVED)) {
 135                 *error = illegal_port;
 136                 return NULL;
 137         }
 138         *error = success;
 139
 140         return exp;
 141 }
 142
 143 nfs_export *
 144 auth_authenticate(char *what, struct sockaddr_in *caller, char *path)
 145 {
 146         nfs_export      *exp = NULL;
 147         char            epath[MAXPATHLEN+1];
 148         char            *p = NULL;
 149         struct hostent  *hp = NULL;
 150         struct in_addr  addr = caller->sin_addr;
 151         enum auth_error error;
 152
 153         if (path [0] != '/') {
 154                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 155                      what, inet_ntoa(addr), path);
 156                 return exp;
 157         }
 158
 159         strncpy(epath, path, sizeof (epath) - 1);
 160         epath[sizeof (epath) - 1] = '\0';
 161         auth_fixpath(epath); /* strip duplicate '/' etc */
 162
 163         hp = client_resolve(caller->sin_addr);
 164         if (!hp)
 165                 return exp;
 166
 167         /* Try the longest matching exported pathname. */
 168         while (1) {
 169                 exp = auth_authenticate_internal(what, caller, epath,
 170                                                  hp, &error);
 171                 if (exp || (error != not_exported && error != no_entry))
 172                         break;
 173                 /* We have to treat the root, "/", specially. */
 174                 if (p == &epath[1]) break;
 175                 p = strrchr(epath, '/');
 176                 if (p == epath) p++;
 177                 *p = '\0';
 178         }
 179
 180         switch (error) {
 181         case bad_path:
 182                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 183                      what, inet_ntoa(addr), path);
 184                 break;
 185
 186         case unknown_host:
 187                 xlog(L_WARNING, "%s request from unknown host %s for %s (%s)",
 188                      what, inet_ntoa(addr), path, epath);
 189                 break;
 190
 191         case no_entry:
 192                 xlog(L_WARNING, "refused %s request from %s for %s (%s): no export entry",
 193                      what, hp->h_name, path, epath);
 194                 break;
 195
 196         case not_exported:
 197                 xlog(L_WARNING, "refused %s request from %s for %s (%s): not exported",
 198                      what, hp->h_name, path, epath);
 199                 break;
 200
 201         case illegal_port:
 202                 xlog(L_WARNING, "refused %s request from %s for %s (%s): illegal port %d",
 203                      what, hp->h_name, path, epath, ntohs(caller->sin_port));
 204                 break;
 205
 206         case success:
 207                 xlog(L_NOTICE, "authenticated %s request from %s:%d for %s (%s)",
 208                      what, hp->h_name, ntohs(caller->sin_port), path, epath);
 209                 break;
 210         default:
 211                 xlog(L_NOTICE, "%s request from %s:%d for %s (%s) gave %d",
 212                      what, hp->h_name, ntohs(caller->sin_port), path, epath, error);
 213         }
 214
 215         if (hp)
 216                 free (hp);
 217
 218         return exp;
 219 }
 220
 221 static void
 222 auth_fixpath(char *path)
 223 {
 224         char    *sp, *cp;
 225
 226         for (sp = cp = path; *sp; sp++) {
 227                 if (*sp != '/' || sp[1] != '/')
 228                         *cp++ = *sp;
 229         }
 230         while (cp > path+1 && cp[-1] == '/')
 231                 cp--;
 232         *cp = '\0';
 233 }