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                         if (!n)
  84                                 return NULL;
  85                         strcpy(my_client.m_hostname, *n?n:"DEFAULT");
  86                         free(n);
  87                         my_client.m_naddr = 1;
  88                 }
  89
  90                 my_exp.m_client = &my_client;
  91
  92                 exp = NULL;
  93                 for (i = 0; !exp && i < MCL_MAXTYPES; i++)
  94                         for (exp = exportlist[i]; exp; exp = exp->m_next) {
  95                                 if (!client_member(my_client.m_hostname, exp->m_client->m_hostname))
  96                                         continue;
  97                                 if (strcmp(path, exp->m_export.e_path))
  98                                         continue;
  99                                 break;
 100                         }
 101                 *error = not_exported;
 102                 if (!exp)
 103                         return exp;
 104
 105                 my_exp.m_export = exp->m_export;
 106                 exp = &my_exp;
 107
 108         } else {
 109                 if (!(exp = export_find(hp, path))) {
 110                         *error = no_entry;
 111                         return NULL;
 112                 }
 113                 if (!exp->m_mayexport) {
 114                         *error = not_exported;
 115                         return NULL;
 116                 }
 117         }
 118         if (!(exp->m_export.e_flags & NFSEXP_INSECURE_PORT) &&
 119                     (ntohs(caller->sin_port) <  IPPORT_RESERVED/2 ||
 120                      ntohs(caller->sin_port) >= IPPORT_RESERVED)) {
 121                 *error = illegal_port;
 122                 return NULL;
 123         }
 124         *error = success;
 125
 126         return exp;
 127 }
 128
 129 nfs_export *
 130 auth_authenticate(char *what, struct sockaddr_in *caller, char *path)
 131 {
 132         nfs_export      *exp = NULL;
 133         char            epath[MAXPATHLEN+1];
 134         char            *p = NULL;
 135         struct hostent  *hp = NULL;
 136         struct in_addr  addr = caller->sin_addr;
 137         enum auth_error error;
 138
 139         if (path [0] != '/') {
 140                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 141                      what, inet_ntoa(addr), path);
 142                 return exp;
 143         }
 144
 145         strncpy(epath, path, sizeof (epath) - 1);
 146         epath[sizeof (epath) - 1] = '\0';
 147         auth_fixpath(epath); /* strip duplicate '/' etc */
 148
 149         hp = get_reliable_hostbyaddr((const char*)&caller->sin_addr, sizeof(struct in_addr),
 150                                      AF_INET);
 151         if (!hp)
 152                 hp = get_hostent((const char*)&caller->sin_addr, sizeof(struct in_addr),
 153                                      AF_INET);
 154         if (!hp)
 155                 return exp;
 156
 157         /* Try the longest matching exported pathname. */
 158         while (1) {
 159                 exp = auth_authenticate_internal(what, caller, epath,
 160                                                  hp, &error);
 161                 if (exp || (error != not_exported && error != no_entry))
 162                         break;
 163                 /* We have to treat the root, "/", specially. */
 164                 if (p == &epath[1]) break;
 165                 p = strrchr(epath, '/');
 166                 if (p == epath) p++;
 167                 *p = '\0';
 168         }
 169
 170         switch (error) {
 171         case bad_path:
 172                 xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
 173                      what, inet_ntoa(addr), path);
 174                 break;
 175
 176         case unknown_host:
 177                 xlog(L_WARNING, "%s request from unknown host %s for %s (%s)",
 178                      what, inet_ntoa(addr), path, epath);
 179                 break;
 180
 181         case no_entry:
 182                 xlog(L_WARNING, "refused %s request from %s for %s (%s): no export entry",
 183                      what, hp->h_name, path, epath);
 184                 break;
 185
 186         case not_exported:
 187                 xlog(L_WARNING, "refused %s request from %s for %s (%s): not exported",
 188                      what, hp->h_name, path, epath);
 189                 break;
 190
 191         case illegal_port:
 192                 xlog(L_WARNING, "refused %s request from %s for %s (%s): illegal port %d",
 193                      what, hp->h_name, path, epath, ntohs(caller->sin_port));
 194                 break;
 195
 196         case success:
 197                 xlog(L_NOTICE, "authenticated %s request from %s:%d for %s (%s)",
 198                      what, hp->h_name, ntohs(caller->sin_port), path, epath);
 199                 break;
 200         default:
 201                 xlog(L_NOTICE, "%s request from %s:%d for %s (%s) gave %d",
 202                      what, hp->h_name, ntohs(caller->sin_port), path, epath, error);
 203         }
 204
 205         if (hp)
 206                 free (hp);
 207
 208         return exp;
 209 }
 210
 211 static void
 212 auth_fixpath(char *path)
 213 {
 214         char    *sp, *cp;
 215
 216         for (sp = cp = path; *sp; sp++) {
 217                 if (*sp != '/' || sp[1] != '/')
 218                         *cp++ = *sp;
 219         }
 220         while (cp > path+1 && cp[-1] == '/')
 221                 cp--;
 222         *cp = '\0';
 223 }