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 #include "config.h"
  10
  11 #include <sys/stat.h>
  12 #include <netinet/in.h>
  13 #include <arpa/inet.h>
  14 #include <errno.h>
  15 #include "misc.h"
  16 #include "nfslib.h"
  17 #include "exportfs.h"
  18 #include "mountd.h"
  19 #include "xmalloc.h"
  20
  21 enum auth_error
  22 {
  23   bad_path,
  24   unknown_host,
  25   no_entry,
  26   not_exported,
  27   illegal_port,
  28   success
  29 };
  30
  31 static void             auth_fixpath(char *path);
  32 static char     *export_file = NULL;
  33
  34 extern int new_cache;
  35
  36 void
  37 auth_init(char *exports)
  38 {
  39
  40         export_file = exports;
  41         auth_reload();
  42         xtab_mount_write();
  43 }
  44
  45 int
  46 auth_reload()
  47 {
  48         struct stat             stb;
  49         static time_t           last_modified = 0;
  50
  51         if (stat(_PATH_ETAB, &stb) < 0)
  52                 xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB);
  53         if (stb.st_mtime == last_modified)
  54                 return 0;
  55         last_modified = stb.st_mtime;
  56
  57         export_freeall();
  58         // export_read(export_file);
  59         xtab_export_read();
  60
  61         return 1;
  62 }
  63
  64 static nfs_export *
  65 auth_authenticate_internal(char *what, struct sockaddr_in *caller,
  66                            char *path, struct hostent *hp,
  67                            enum auth_error *error)
  68 {
  69         nfs_export              *exp;
  70
  71         if (new_cache) {
  72                 static nfs_export my_exp;
  73                 static nfs_client my_client;
  74                 int i;
  75                 /* return static nfs_export with details filled in */
  76                 if (my_client.m_naddr != 1 ||
  77                     my_client.m_addrlist[0].s_addr != caller->sin_addr.s_addr) {
  78                         /* different client to last time, so do a lookup */
  79                         char *n;
  80                         my_client.m_naddr = 0;
  81                         my_client.m_addrlist[0] = caller->sin_addr;
  82                         n = client_compose(caller->sin_addr);
  83                         *error = unknown_host;
  84                         if (!n)
  85                                 return NULL;
  86                         strcpy(my_client.m_hostname, *n?n:"DEFAULT");
  87                         free(n);
  88                         my_client.m_naddr = 1;
  89                 }
  90
  91                 my_exp.m_client = &my_client;
  92
  93                 exp = NULL;
  94                 for (i = 0; !exp && i < MCL_MAXTYPES; i++)
  95                         for (exp = exportlist[i]; exp; exp = exp->m_next) {
  96                                 if (!client_member(my_client.m_hostname, exp->m_client->m_hostname))
  97                                         continue;
  98                                 if (strcmp(path, exp->m_export.e_path))
  99                                         continue;
 100                                 break;
 101                         }
 102                 *error = not_exported;
 103                 if (!exp)
 104                         return exp;
 105
 106                 my_exp.m_export = exp->m_export;
 107                 exp = &my_exp;
 108
 109         } else {
 110                 if (!(exp = export_find(hp, path))) {
 111                         *error = no_entry;
 112                         return NULL;
 113                 }
 114                 if (!exp->m_mayexport) {
 115                         *error = not_exported;
 116                         return NULL;
 117                 }
 118         }
 119         if (!(exp->m_export.e_flags & NFSEXP_INSECURE_PORT) &&
 120                     (ntohs(caller->sin_port) <  IPPORT_RESERVED/2 ||
 121                      ntohs(caller->sin_port) >= IPPORT_RESERVED)) {
 122                 *error = illegal_port;
 123                 return NULL;
 124         }
 125         *error = success;
 126
 127         return exp;
 128 }
 129
 130 nfs_export *
 131 auth_authenticate(char *what, struct sockaddr_in *caller, char *path)
 132 {
 133         nfs_export      *exp = NULL;
 134         char            epath[MAXPATHLEN+1];
 135         char            *p = NULL;
 136         struct hostent  *hp = NULL;
 137         struct in_addr  addr = caller->sin_addr;
 138         enum auth_error error;
 139
 140         if (path [0] != '/') {
 141                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 142                      what, inet_ntoa(addr), path);
 143                 return exp;
 144         }
 145
 146         strncpy(epath, path, sizeof (epath) - 1);
 147         epath[sizeof (epath) - 1] = '\0';
 148         auth_fixpath(epath); /* strip duplicate '/' etc */
 149
 150         hp = get_reliable_hostbyaddr((const char*)&caller->sin_addr, sizeof(struct in_addr),
 151                                      AF_INET);
 152         if (!hp)
 153                 hp = get_hostent((const char*)&caller->sin_addr, sizeof(struct in_addr),
 154                                      AF_INET);
 155         if (!hp)
 156                 return exp;
 157
 158         /* Try the longest matching exported pathname. */
 159         while (1) {
 160                 exp = auth_authenticate_internal(what, caller, epath,
 161                                                  hp, &error);
 162                 if (exp || (error != not_exported && error != no_entry))
 163                         break;
 164                 /* We have to treat the root, "/", specially. */
 165                 if (p == &epath[1]) break;
 166                 p = strrchr(epath, '/');
 167                 if (p == epath) p++;
 168                 *p = '\0';
 169         }
 170
 171         switch (error) {
 172         case bad_path:
 173                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 174                      what, inet_ntoa(addr), path);
 175                 break;
 176
 177         case unknown_host:
 178                 xlog(L_WARNING, "%s request from unknown host %s for %s (%s)",
 179                      what, inet_ntoa(addr), path, epath);
 180                 break;
 181
 182         case no_entry:
 183                 xlog(L_WARNING, "refused %s request from %s for %s (%s): no export entry",
 184                      what, hp->h_name, path, epath);
 185                 break;
 186
 187         case not_exported:
 188                 xlog(L_WARNING, "refused %s request from %s for %s (%s): not exported",
 189                      what, hp->h_name, path, epath);
 190                 break;
 191
 192         case illegal_port:
 193                 xlog(L_WARNING, "refused %s request from %s for %s (%s): illegal port %d",
 194                      what, hp->h_name, path, epath, ntohs(caller->sin_port));
 195                 break;
 196
 197         case success:
 198                 xlog(L_NOTICE, "authenticated %s request from %s:%d for %s (%s)",
 199                      what, hp->h_name, ntohs(caller->sin_port), path, epath);
 200                 break;
 201         default:
 202                 xlog(L_NOTICE, "%s request from %s:%d for %s (%s) gave %d",
 203                      what, hp->h_name, ntohs(caller->sin_port), path, epath, error);
 204         }
 205
 206         if (hp)
 207                 free (hp);
 208
 209         return exp;
 210 }
 211
 212 static void
 213 auth_fixpath(char *path)
 214 {
 215         char    *sp, *cp;
 216
 217         for (sp = cp = path; *sp; sp++) {
 218                 if (*sp != '/' || sp[1] != '/')
 219                         *cp++ = *sp;
 220         }
 221         while (cp > path+1 && cp[-1] == '/')
 222                 cp--;
 223         *cp = '\0';
 224 }