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