libcli/nbt/lmhosts.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    manipulate nbt name structures
   5
   6    Copyright (C) Andrew Tridgell 1994-1998
   7    Copyright (C) Jeremy Allison 2007
   8    Copyright (C) Andrew Bartlett 2009.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22 */
  23
  24 #include "includes.h"
  25 #include "lib/util/util_net.h"
  26 #include "system/filesys.h"
  27 #include "system/network.h"
  28 #include "../libcli/nbt/libnbt.h"
  29
  30 /********************************************************
  31  Start parsing the lmhosts file.
  32 *********************************************************/
  33
  34 FILE *startlmhosts(const char *fname)
  35 {
  36         FILE *fp = fopen(fname, "r");
  37         if (!fp) {
  38                 DEBUG(4,("startlmhosts: Can't open lmhosts file %s. "
  39                         "Error was %s\n",
  40                         fname, strerror(errno)));
  41                 return NULL;
  42         }
  43         return fp;
  44 }
  45
  46 /********************************************************
  47  Parse the next line in the lmhosts file.
  48 *********************************************************/
  49
  50 bool getlmhostsent(TALLOC_CTX *ctx, FILE *fp, char **pp_name, int *name_type,
  51                    struct sockaddr_storage *pss)
  52 {
  53         char line[1024];
  54
  55         *pp_name = NULL;
  56
  57         while(!feof(fp) && !ferror(fp)) {
  58                 char *ip = NULL;
  59                 char *flags = NULL;
  60                 char *extra = NULL;
  61                 char *name = NULL;
  62                 const char *ptr;
  63                 char *ptr1 = NULL;
  64                 int count = 0;
  65
  66                 *name_type = -1;
  67
  68                 if (!fgets_slash(NULL,line,sizeof(line),fp)) {
  69                         continue;
  70                 }
  71
  72                 if (*line == '#') {
  73                         continue;
  74                 }
  75
  76                 ptr = line;
  77
  78                 if (next_token_talloc(ctx, &ptr, &ip, NULL))
  79                         ++count;
  80                 if (next_token_talloc(ctx, &ptr, &name, NULL))
  81                         ++count;
  82                 if (next_token_talloc(ctx, &ptr, &flags, NULL))
  83                         ++count;
  84                 if (next_token_talloc(ctx, &ptr, &extra, NULL))
  85                         ++count;
  86
  87                 if (count <= 0)
  88                         continue;
  89
  90                 if (count > 0 && count < 2) {
  91                         DEBUG(0,("getlmhostsent: Ill formed hosts line [%s]\n",
  92                                                 line));
  93                         continue;
  94                 }
  95
  96                 if (count >= 4) {
  97                         DEBUG(0,("getlmhostsent: too many columns "
  98                                 "in lmhosts file (obsolete syntax)\n"));
  99                         continue;
 100                 }
 101
 102                 if (!flags) {
 103                         flags = talloc_strdup(ctx, "");
 104                         if (!flags) {
 105                                 continue;
 106                         }
 107                 }
 108
 109                 DEBUG(4, ("getlmhostsent: lmhost entry: %s %s %s\n",
 110                                         ip, name, flags));
 111
 112                 if (strchr_m(flags,'G') || strchr_m(flags,'S')) {
 113                         DEBUG(0,("getlmhostsent: group flag "
 114                                 "in lmhosts ignored (obsolete)\n"));
 115                         continue;
 116                 }
 117
 118                 if (!interpret_string_addr(pss, ip, AI_NUMERICHOST)) {
 119                         DEBUG(0,("getlmhostsent: invalid address "
 120                                 "%s.\n", ip));
 121                 }
 122
 123                 /* Extra feature. If the name ends in '#XX',
 124                  * where XX is a hex number, then only add that name type. */
 125                 if((ptr1 = strchr_m(name, '#')) != NULL) {
 126                         char *endptr;
 127                         ptr1++;
 128
 129                         *name_type = (int)strtol(ptr1, &endptr, 16);
 130                         if(!*ptr1 || (endptr == ptr1)) {
 131                                 DEBUG(0,("getlmhostsent: invalid name "
 132                                         "%s containing '#'.\n", name));
 133                                 continue;
 134                         }
 135
 136                         *(--ptr1) = '\0'; /* Truncate at the '#' */
 137                 }
 138
 139                 *pp_name = talloc_strdup(ctx, name);
 140                 if (!*pp_name) {
 141                         return false;
 142                 }
 143                 return true;
 144         }
 145
 146         return false;
 147 }
 148
 149 /********************************************************
 150  Finish parsing the lmhosts file.
 151 *********************************************************/
 152
 153 void endlmhosts(FILE *fp)
 154 {
 155         fclose(fp);
 156 }
 157
 158 /********************************************************
 159  Resolve via "lmhosts" method.
 160 *********************************************************/
 161
 162 NTSTATUS resolve_lmhosts_file_as_sockaddr(const char *lmhosts_file,
 163                                           const char *name, int name_type,
 164                                           TALLOC_CTX *mem_ctx,
 165                                           struct sockaddr_storage **return_iplist,
 166                                           int *return_count)
 167 {
 168         /*
 169          * "lmhosts" means parse the local lmhosts file.
 170          */
 171
 172         FILE *fp;
 173         char *lmhost_name = NULL;
 174         int name_type2;
 175         struct sockaddr_storage return_ss;
 176         NTSTATUS status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
 177         TALLOC_CTX *ctx = NULL;
 178
 179         *return_iplist = NULL;
 180         *return_count = 0;
 181
 182         DEBUG(3,("resolve_lmhosts: "
 183                 "Attempting lmhosts lookup for name %s<0x%x>\n",
 184                 name, name_type));
 185
 186         fp = startlmhosts(lmhosts_file);
 187
 188         if ( fp == NULL )
 189                 return NT_STATUS_NO_SUCH_FILE;
 190
 191         ctx = talloc_new(mem_ctx);
 192         if (!ctx) {
 193                 endlmhosts(fp);
 194                 return NT_STATUS_NO_MEMORY;
 195         }
 196
 197         while (getlmhostsent(ctx, fp, &lmhost_name, &name_type2, &return_ss)) {
 198
 199                 if (!strequal(name, lmhost_name)) {
 200                         TALLOC_FREE(lmhost_name);
 201                         continue;
 202                 }
 203
 204                 if ((name_type2 != -1) && (name_type != name_type2)) {
 205                         TALLOC_FREE(lmhost_name);
 206                         continue;
 207                 }
 208
 209                 *return_iplist = talloc_realloc(ctx, (*return_iplist),
 210                                                 struct sockaddr_storage,
 211                                                 (*return_count)+1);
 212
 213                 if ((*return_iplist) == NULL) {
 214                         TALLOC_FREE(ctx);
 215                         endlmhosts(fp);
 216                         DEBUG(3,("resolve_lmhosts: talloc_realloc fail !\n"));
 217                         return NT_STATUS_NO_MEMORY;
 218                 }
 219
 220                 (*return_iplist)[*return_count] = return_ss;
 221                 *return_count += 1;
 222
 223                 /* we found something */
 224                 status = NT_STATUS_OK;
 225
 226                 /* Multiple names only for DC lookup */
 227                 if (name_type != 0x1c)
 228                         break;
 229         }
 230
 231         talloc_steal(mem_ctx, *return_iplist);
 232         TALLOC_FREE(ctx);
 233         endlmhosts(fp);
 234         return status;
 235 }
 236