source4/libcli/nbt/nbtname.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    manipulate nbt name structures
   5
   6    Copyright (C) Andrew Tridgell 2005
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  21 */
  22
  23 /*
  24   see rfc1002 for the detailed format of compressed names
  25 */
  26
  27 #include "includes.h"
  28 #include "librpc/gen_ndr/ndr_nbt.h"
  29
  30 /* don't allow an unlimited number of name components */
  31 #define MAX_COMPONENTS 10
  32
  33 /*
  34   pull one component of a compressed name
  35 */
  36 static NTSTATUS ndr_pull_component(struct ndr_pull *ndr, uint8_t **component,
  37                                    uint32_t *offset, uint32_t *max_offset)
  38 {
  39         uint8_t len;
  40         uint_t loops = 0;
  41         while (loops < 5) {
  42                 if (*offset >= ndr->data_size) {
  43                         return NT_STATUS_BAD_NETWORK_NAME;
  44                 }
  45                 len = ndr->data[*offset];
  46                 if (len == 0) {
  47                         *offset += 1;
  48                         *max_offset = MAX(*max_offset, *offset);
  49                         *component = NULL;
  50                         return NT_STATUS_OK;
  51                 }
  52                 if ((len & 0xC0) == 0xC0) {
  53                         /* its a label pointer */
  54                         if (1 + *offset >= ndr->data_size) {
  55                                 return NT_STATUS_BAD_NETWORK_NAME;
  56                         }
  57                         *offset = ((len&0x3F)<<8) | ndr->data[1 + *offset];
  58                         *max_offset = MAX(*max_offset, *offset + 1);
  59                         loops++;
  60                         continue;
  61                 }
  62                 if ((len & 0xC0) != 0) {
  63                         /* its a reserved length field */
  64                         return NT_STATUS_BAD_NETWORK_NAME;
  65                 }
  66                 if (*offset + len + 2 > ndr->data_size) {
  67                         return NT_STATUS_BAD_NETWORK_NAME;
  68                 }
  69                 *component = (uint8_t*)talloc_strndup(ndr, &ndr->data[1 + *offset], len);
  70                 NT_STATUS_HAVE_NO_MEMORY(*component);
  71                 *offset += len + 1;
  72                 *max_offset = MAX(*max_offset, *offset);
  73                 return NT_STATUS_OK;
  74         }
  75
  76         /* too many pointers */
  77         return NT_STATUS_BAD_NETWORK_NAME;
  78 }
  79
  80 /*
  81   decompress a 'compressed' name component
  82  */
  83 static NTSTATUS decompress_name(char *name, enum nbt_name_type *type)
  84 {
  85         int i;
  86         for (i=0;name[2*i];i++) {
  87                 uint8_t c1 = name[2*i];
  88                 uint8_t c2 = name[1+(2*i)];
  89                 if (c1 < 'A' || c1 > 'P' ||
  90                     c2 < 'A' || c2 > 'P') {
  91                         return NT_STATUS_BAD_NETWORK_NAME;
  92                 }
  93                 name[i] = ((c1-'A')<<4) | (c2-'A');
  94         }
  95         name[i] = 0;
  96         if (i == 16) {
  97                 *type = (enum nbt_name_type)(name[15]);
  98                 name[15] = 0;
  99                 i--;
 100         } else {
 101                 *type = NBT_NAME_CLIENT;
 102         }
 103
 104         /* trim trailing spaces */
 105         for (;i>0 && name[i-1]==' ';i--) {
 106                 name[i-1] = 0;
 107         }
 108
 109         return NT_STATUS_OK;
 110 }
 111
 112
 113 /*
 114   compress a name component
 115  */
 116 static uint8_t *compress_name(TALLOC_CTX *mem_ctx,
 117                               uint8_t *name, enum nbt_name_type type)
 118 {
 119         uint8_t *cname;
 120         int i;
 121         uint8_t pad_char;
 122
 123         if (strlen(name) > 15) {
 124                 return NULL;
 125         }
 126
 127         cname = talloc_array(mem_ctx, uint8_t, 33);
 128         if (cname == NULL) return NULL;
 129
 130         for (i=0;name[i];i++) {
 131                 cname[2*i]   = 'A' + (name[i]>>4);
 132                 cname[1+2*i] = 'A' + (name[i]&0xF);
 133         }
 134         if (name[0] == '*') {
 135                 pad_char = 0;
 136         } else {
 137                 pad_char = ' ';
 138         }
 139         for (;i<15;i++) {
 140                 cname[2*i]   = 'A' + (pad_char>>4);
 141                 cname[1+2*i] = 'A' + (pad_char&0xF);
 142         }
 143
 144         pad_char = type;
 145         cname[2*i]   = 'A' + (pad_char>>4);
 146         cname[1+2*i] = 'A' + (pad_char&0xF);
 147
 148         cname[32] = 0;
 149         return cname;
 150 }
 151
 152 /*
 153   pull a nbt name from the wire
 154 */
 155 NTSTATUS ndr_pull_nbt_name(struct ndr_pull *ndr, int ndr_flags, struct nbt_name *r)
 156 {
 157         NTSTATUS status;
 158         uint_t num_components;
 159         uint32_t offset = ndr->offset;
 160         uint32_t max_offset = offset;
 161         uint8_t *components[MAX_COMPONENTS];
 162         int i;
 163         ssize_t ret;
 164         void *p;
 165         uint8_t *scope;
 166
 167         if (!(ndr_flags & NDR_SCALARS)) {
 168                 return NT_STATUS_OK;
 169         }
 170
 171         /* break up name into a list of components */
 172         for (num_components=0;num_components<MAX_COMPONENTS;num_components++) {
 173                 status = ndr_pull_component(ndr, &components[num_components],
 174                                             &offset, &max_offset);
 175                 NT_STATUS_NOT_OK_RETURN(status);
 176                 if (components[num_components] == NULL) break;
 177         }
 178         if (num_components == MAX_COMPONENTS ||
 179             num_components == 0) {
 180                 return NT_STATUS_BAD_NETWORK_NAME;
 181         }
 182
 183         ndr->offset = max_offset;
 184
 185         /* the first component is limited to 16 bytes in the DOS charset,
 186            which is 32 in the 'compressed' form */
 187         if (strlen(components[0]) > 32) {
 188                 return NT_STATUS_BAD_NETWORK_NAME;
 189         }
 190
 191         /* decompress the first component */
 192         status = decompress_name(components[0], &r->type);
 193         NT_STATUS_NOT_OK_RETURN(status);
 194
 195         ret = convert_string_talloc(ndr, CH_DOS, CH_UNIX, components[0],
 196                                     strlen(components[0])+1, &p);
 197         if (ret <= 0) {
 198                 return NT_STATUS_BAD_NETWORK_NAME;
 199         }
 200         r->name = p;
 201
 202         /* combine the remaining components into the scope */
 203         scope = components[1];
 204         for (i=2;i<num_components;i++) {
 205                 talloc_asprintf_append(scope, ".%s", components[i]);
 206         }
 207
 208         if (scope) {
 209                 ret = convert_string_talloc(ndr, CH_DOS, CH_UNIX, scope,
 210                                             strlen(r->scope)+1, &p);
 211                 if (ret <= 0) {
 212                         return NT_STATUS_BAD_NETWORK_NAME;
 213                 }
 214                 r->scope = p;
 215         } else {
 216                 r->scope = NULL;
 217         }
 218
 219         return NT_STATUS_OK;
 220 }
 221
 222 /*
 223   push a nbt name to the wire
 224 */
 225 NTSTATUS ndr_push_nbt_name(struct ndr_push *ndr, int ndr_flags, struct nbt_name *r)
 226 {
 227         uint_t num_components;
 228         uint8_t *components[MAX_COMPONENTS];
 229         void *ptr;
 230         char *dname, *dscope=NULL, *p;
 231         uint8_t *cname;
 232         ssize_t ret;
 233         int i;
 234
 235         if (!(ndr_flags & NDR_SCALARS)) {
 236                 return NT_STATUS_OK;
 237         }
 238
 239         /* convert to DOS format */
 240         ret = convert_string_talloc(ndr, CH_UNIX, CH_DOS, r->name,
 241                                     strlen(r->name)+1, &ptr);
 242         if (ret <= 0) {
 243                 return NT_STATUS_BAD_NETWORK_NAME;
 244         }
 245         dname = strupper_talloc(ndr, ptr);
 246         NT_STATUS_HAVE_NO_MEMORY(dname);
 247         if (r->scope) {
 248                 ret = convert_string_talloc(ndr, CH_UNIX, CH_DOS, r->scope,
 249                                             strlen(r->scope)+1, &ptr);
 250                 if (ret <= 0) {
 251                         return NT_STATUS_BAD_NETWORK_NAME;
 252                 }
 253                 dscope = strupper_talloc(ndr, ptr);
 254                 NT_STATUS_HAVE_NO_MEMORY(dscope);
 255         }
 256
 257         cname = compress_name(ndr, dname, r->type);
 258         NT_STATUS_HAVE_NO_MEMORY(cname);
 259
 260         /* form the base components */
 261         components[0] = cname;
 262         num_components = 1;
 263
 264         while (dscope && (p=strchr(dscope, '.')) &&
 265                num_components < MAX_COMPONENTS) {
 266                 *p = 0;
 267                 components[num_components] = dscope;
 268                 NT_STATUS_HAVE_NO_MEMORY(components[num_components]);
 269                 dscope = p+1;
 270                 num_components++;
 271         }
 272         if (num_components == MAX_COMPONENTS) {
 273                 return NT_STATUS_BAD_NETWORK_NAME;
 274         }
 275
 276         /* push the components */
 277         for (i=0;i<num_components;i++) {
 278                 uint8_t len = strlen(components[i]);
 279                 NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, len));
 280                 NDR_CHECK(ndr_push_bytes(ndr, components[i], len));
 281         }
 282         NDR_CHECK(ndr_push_uint8(ndr, NDR_SCALARS, 0));
 283
 284         return NT_STATUS_OK;
 285 }
 286
 287
 288 /*
 289   copy a nbt name structure
 290 */
 291 NTSTATUS nbt_name_dup(TALLOC_CTX *mem_ctx, struct nbt_name *name, struct nbt_name *newname)
 292 {
 293         *newname = *name;
 294         newname->name = talloc_strdup(mem_ctx, newname->name);
 295         NT_STATUS_HAVE_NO_MEMORY(newname->name);
 296         newname->scope = talloc_strdup(mem_ctx, newname->scope);
 297         if (name->scope) {
 298                 NT_STATUS_HAVE_NO_MEMORY(newname->scope);
 299         }
 300         return NT_STATUS_OK;
 301 }
 302
 303 /*
 304   push a nbt name into a blob
 305 */
 306 NTSTATUS nbt_name_to_blob(TALLOC_CTX *mem_ctx, DATA_BLOB *blob, struct nbt_name *name)
 307 {
 308         return ndr_push_struct_blob(blob, mem_ctx, name,
 309                                     (ndr_push_flags_fn_t)ndr_push_nbt_name);
 310 }
 311
 312
 313 /*
 314   pull a nbt name from a blob
 315 */
 316 NTSTATUS nbt_name_from_blob(TALLOC_CTX *mem_ctx, const DATA_BLOB *blob, struct nbt_name *name)
 317 {
 318         return ndr_pull_struct_blob(blob, mem_ctx, name,
 319                                     (ndr_pull_flags_fn_t)ndr_pull_nbt_name);
 320 }
 321
 322
 323 /*
 324   choose a name to use when calling a server in a NBT session request.
 325   we use heuristics to see if the name we have been given is a IP
 326   address, or a too-long name. If it is then use *SMBSERVER, or a
 327   truncated name
 328 */
 329 void nbt_choose_called_name(TALLOC_CTX *mem_ctx,
 330                             struct nbt_name *n, const char *name, int type)
 331 {
 332         n->scope = NULL;
 333         n->type = type;
 334
 335         if (is_ipaddress(name)) {
 336                 n->name = "*SMBSERVER";
 337                 return;
 338         }
 339         if (strlen(name) > 15) {
 340                 const char *p = strchr(name, '.');
 341                 if (p - name > 15) {
 342                         n->name = "*SMBSERVER";
 343                         return;
 344                 }
 345                 n->name = talloc_strndup(mem_ctx, name, PTR_DIFF(p, name));
 346                 return;
 347         }
 348
 349         n->name = talloc_strdup(mem_ctx, name);
 350 }