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_file.h"
  26 #include "lib/util/util_net.h"
  27 #include "system/filesys.h"
  28 #include "system/network.h"
  29 #include "../libcli/nbt/libnbt.h"
  30
  31 /********************************************************
  32  Start parsing the lmhosts file.
  33 *********************************************************/
  34
  35 FILE *startlmhosts(const char *fname)
  36 {
  37         FILE *fp = fopen(fname, "r");
  38         if (!fp) {
  39                 DEBUG(4,("startlmhosts: Can't open lmhosts file %s. "
  40                         "Error was %s\n",
  41                         fname, strerror(errno)));
  42                 return NULL;
  43         }
  44         return fp;
  45 }
  46
  47 /********************************************************
  48  Parse the next line in the lmhosts file.
  49 *********************************************************/
  50
  51 bool getlmhostsent(TALLOC_CTX *ctx, FILE *fp, char **pp_name, int *name_type,
  52                    struct sockaddr_storage *pss)
  53 {
  54         char line[1024];
  55
  56         *pp_name = NULL;
  57
  58         while(!feof(fp) && !ferror(fp)) {
  59                 char *ip = NULL;
  60                 char *flags = NULL;
  61                 char *extra = NULL;
  62                 char *name = NULL;
  63                 const char *ptr;
  64                 char *ptr1 = NULL;
  65                 int count = 0;
  66
  67                 *name_type = -1;
  68
  69                 if (!fgets_slash(NULL,line,sizeof(line),fp)) {
  70                         continue;
  71                 }
  72
  73                 if (*line == '#') {
  74                         continue;
  75                 }
  76
  77                 ptr = line;
  78
  79                 if (next_token_talloc(ctx, &ptr, &ip, NULL))
  80                         ++count;
  81                 if (next_token_talloc(ctx, &ptr, &name, NULL))
  82                         ++count;
  83                 if (next_token_talloc(ctx, &ptr, &flags, NULL))
  84                         ++count;
  85                 if (next_token_talloc(ctx, &ptr, &extra, NULL))
  86                         ++count;
  87
  88                 if (count <= 0)
  89                         continue;
  90
  91                 if (count > 0 && count < 2) {
  92                         DEBUG(0,("getlmhostsent: Ill formed hosts line [%s]\n",
  93                                                 line));
  94                         continue;
  95                 }
  96
  97                 if (count >= 4) {
  98                         DEBUG(0,("getlmhostsent: too many columns "
  99                                 "in lmhosts file (obsolete syntax)\n"));
 100                         continue;
 101                 }
 102
 103                 if (!flags) {
 104                         flags = talloc_strdup(ctx, "");
 105                         if (!flags) {
 106                                 continue;
 107                         }
 108                 }
 109
 110                 DEBUG(4, ("getlmhostsent: lmhost entry: %s %s %s\n",
 111                                         ip, name, flags));
 112
 113                 if (strchr_m(flags,'G') || strchr_m(flags,'S')) {
 114                         DEBUG(0,("getlmhostsent: group flag "
 115                                 "in lmhosts ignored (obsolete)\n"));
 116                         continue;
 117                 }
 118
 119                 if (!interpret_string_addr(pss, ip, AI_NUMERICHOST)) {
 120                         DEBUG(0,("getlmhostsent: invalid address "
 121                                 "%s.\n", ip));
 122                 }
 123
 124                 /* Extra feature. If the name ends in '#XX',
 125                  * where XX is a hex number, then only add that name type. */
 126                 if((ptr1 = strchr_m(name, '#')) != NULL) {
 127                         char *endptr;
 128                         ptr1++;
 129
 130                         *name_type = (int)strtol(ptr1, &endptr, 16);
 131                         if(!*ptr1 || (endptr == ptr1)) {
 132                                 DEBUG(0,("getlmhostsent: invalid name "
 133                                         "%s containing '#'.\n", name));
 134                                 continue;
 135                         }
 136
 137                         *(--ptr1) = '\0'; /* Truncate at the '#' */
 138                 }
 139
 140                 *pp_name = talloc_strdup(ctx, name);
 141                 if (!*pp_name) {
 142                         return false;
 143                 }
 144                 return true;
 145         }
 146
 147         return false;
 148 }
 149
 150 /********************************************************
 151  Finish parsing the lmhosts file.
 152 *********************************************************/
 153
 154 void endlmhosts(FILE *fp)
 155 {
 156         fclose(fp);
 157 }
 158
 159 /********************************************************
 160  Resolve via "lmhosts" method.
 161 *********************************************************/
 162
 163 NTSTATUS resolve_lmhosts_file_as_sockaddr(TALLOC_CTX *mem_ctx,
 164                                           const char *lmhosts_file,
 165                                           const char *name,
 166                                           int name_type,
 167                                           struct sockaddr_storage **return_iplist,
 168                                           size_t *return_count)
 169 {
 170         /*
 171          * "lmhosts" means parse the local lmhosts file.
 172          */
 173
 174         FILE *fp;
 175         char *lmhost_name = NULL;
 176         int name_type2;
 177         struct sockaddr_storage return_ss;
 178         NTSTATUS status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;
 179         TALLOC_CTX *ctx = NULL;
 180         size_t ret_count = 0;
 181         struct sockaddr_storage *iplist = NULL;
 182
 183         DEBUG(3,("resolve_lmhosts: "
 184                 "Attempting lmhosts lookup for name %s<0x%x>\n",
 185                 name, name_type));
 186
 187         fp = startlmhosts(lmhosts_file);
 188
 189         if ( fp == NULL )
 190                 return NT_STATUS_NO_SUCH_FILE;
 191
 192         ctx = talloc_new(mem_ctx);
 193         if (!ctx) {
 194                 endlmhosts(fp);
 195                 return NT_STATUS_NO_MEMORY;
 196         }
 197
 198         while (getlmhostsent(ctx, fp, &lmhost_name, &name_type2, &return_ss)) {
 199
 200                 if (!strequal(name, lmhost_name)) {
 201                         TALLOC_FREE(lmhost_name);
 202                         continue;
 203                 }
 204
 205                 if ((name_type2 != -1) && (name_type != name_type2)) {
 206                         TALLOC_FREE(lmhost_name);
 207                         continue;
 208                 }
 209
 210                 /* wrap check. */
 211                 if (ret_count + 1 < ret_count) {
 212                         TALLOC_FREE(ctx);
 213                         endlmhosts(fp);
 214                         return NT_STATUS_INVALID_PARAMETER;
 215                 }
 216                 iplist = talloc_realloc(ctx, iplist,
 217                                 struct sockaddr_storage,
 218                                 ret_count+1);
 219
 220                 if (iplist == NULL) {
 221                         TALLOC_FREE(ctx);
 222                         endlmhosts(fp);
 223                         DEBUG(3,("resolve_lmhosts: talloc_realloc fail !\n"));
 224                         return NT_STATUS_NO_MEMORY;
 225                 }
 226
 227                 iplist[ret_count] = return_ss;
 228                 ret_count += 1;
 229
 230                 /* we found something */
 231                 status = NT_STATUS_OK;
 232
 233                 /* Multiple names only for DC lookup */
 234                 if (name_type != 0x1c)
 235                         break;
 236         }
 237
 238         *return_count = ret_count;
 239         *return_iplist = talloc_move(mem_ctx, &iplist);
 240         TALLOC_FREE(ctx);
 241         endlmhosts(fp);
 242         return status;
 243 }
 244