/*

   Unix SMB/CIFS implementation.

   manipulate nbt name structures

   Copyright (C) Andrew Tridgell 1994-1998

   Copyright (C) Jeremy Allison 2007

   Copyright (C) Andrew Bartlett 2009.

   This program is free software; you can redistribute it and/or modify

   it under the terms of the GNU General Public License as published by

   the Free Software Foundation; either version 3 of the License, or

   (at your option) any later version.

   This program is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License

   along with this program.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "includes.h"

#include "lib/util/util_file.h"

#include "lib/util/util_net.h"

#include "system/filesys.h"

#include "system/network.h"

#include "../libcli/nbt/libnbt.h"

/********************************************************

 Start parsing the lmhosts file.

*********************************************************/

FILE *startlmhosts(const char *fname)

{

  FILE *fp = fopen(fname, "r");

  if (!fp) {

    DEBUG(4,("startlmhosts: Can't open lmhosts file %s. "

      "Error was %s\n",

      fname, strerror(errno)));

    return NULL;

  }

  return fp;

}

/********************************************************

 Parse the next line in the lmhosts file.

*********************************************************/

bool getlmhostsent(TALLOC_CTX *ctx, FILE *fp, char **pp_name, int *name_type,

       struct sockaddr_storage *pss)

{

  char line[1024];

  *pp_name = NULL;

  while(!feof(fp) && !ferror(fp)) {

    char *ip = NULL;

    char *flags = NULL;

    char *extra = NULL;

    char *name = NULL;

    const char *ptr;

    char *ptr1 = NULL;

    int count = 0;

    *name_type = -1;

    if (!fgets_slash(NULL,line,sizeof(line),fp)) {

      continue;

    }

    if (*line == '#') {

      continue;

    }

    ptr = line;

    if (next_token_talloc(ctx, &ptr, &ip, NULL))

      ++count;

    if (next_token_talloc(ctx, &ptr, &name, NULL))

      ++count;

    if (next_token_talloc(ctx, &ptr, &flags, NULL))

      ++count;

    if (next_token_talloc(ctx, &ptr, &extra, NULL))

      ++count;

    if (count <= 0)

      continue;

    if (count > 0 && count < 2) {

      DEBUG(0,("getlmhostsent: Ill formed hosts line [%s]\n",

            line));

      continue;

    }

    if (count >= 4) {

      DEBUG(0,("getlmhostsent: too many columns "

        "in lmhosts file (obsolete syntax)\n"));

      continue;

    }

    if (!flags) {

      flags = talloc_strdup(ctx, "");

      if (!flags) {

        continue;

      }

    }

    DEBUG(4, ("getlmhostsent: lmhost entry: %s %s %s\n",

          ip, name, flags));

    if (strchr_m(flags,'G') || strchr_m(flags,'S')) {

      DEBUG(0,("getlmhostsent: group flag "

        "in lmhosts ignored (obsolete)\n"));

      continue;

    }

    if (!interpret_string_addr(pss, ip, AI_NUMERICHOST)) {

      DEBUG(0,("getlmhostsent: invalid address "

        "%s.\n", ip));

    }

    /* Extra feature. If the name ends in '#XX',

     * where XX is a hex number, then only add that name type. */

    if((ptr1 = strchr_m(name, '#')) != NULL) {

      char *endptr;

            ptr1++;

      *name_type = (int)strtol(ptr1, &endptr, 16);

      if(!*ptr1 || (endptr == ptr1)) {

        DEBUG(0,("getlmhostsent: invalid name "

          "%s containing '#'.\n", name));

        continue;

      }

      *(--ptr1) = '\0'; /* Truncate at the '#' */

    }

    *pp_name = talloc_strdup(ctx, name);

    if (!*pp_name) {

      return false;

    }

    return true;

  }

  return false;

}

/********************************************************

 Finish parsing the lmhosts file.

*********************************************************/

void endlmhosts(FILE *fp)

{

  fclose(fp);

}

/********************************************************

 Resolve via "lmhosts" method.

*********************************************************/

NTSTATUS resolve_lmhosts_file_as_sockaddr(TALLOC_CTX *mem_ctx,

            const char *lmhosts_file,

            const char *name,

            int name_type,

            struct sockaddr_storage **return_iplist,

            size_t *return_count)

{

  /*

   * "lmhosts" means parse the local lmhosts file.

   */

  FILE *fp;

  char *lmhost_name = NULL;

  int name_type2;

  struct sockaddr_storage return_ss;

  NTSTATUS status = NT_STATUS_DOMAIN_CONTROLLER_NOT_FOUND;

  TALLOC_CTX *ctx = NULL;

  size_t ret_count = 0;

  struct sockaddr_storage *iplist = NULL;

  DEBUG(3,("resolve_lmhosts: "

    "Attempting lmhosts lookup for name %s<0x%x>\n",

    name, name_type));

  fp = startlmhosts(lmhosts_file);

  if ( fp == NULL )

    return NT_STATUS_NO_SUCH_FILE;

  ctx = talloc_new(mem_ctx);

  if (!ctx) {

    endlmhosts(fp);

    return NT_STATUS_NO_MEMORY;

  }

  while (getlmhostsent(ctx, fp, &lmhost_name, &name_type2, &return_ss)) {

    if (!strequal(name, lmhost_name)) {

      TALLOC_FREE(lmhost_name);

      continue;

    }

    if ((name_type2 != -1) && (name_type != name_type2)) {

      TALLOC_FREE(lmhost_name);

      continue;

    }

    /* wrap check. */

    if (ret_count + 1 < ret_count) {

      TALLOC_FREE(ctx);

      endlmhosts(fp);

      return NT_STATUS_INVALID_PARAMETER;

    }

    iplist = talloc_realloc(ctx, iplist,

        struct sockaddr_storage,

        ret_count+1);

    if (iplist == NULL) {

      TALLOC_FREE(ctx);

      endlmhosts(fp);

      DEBUG(3,("resolve_lmhosts: talloc_realloc fail !\n"));

      return NT_STATUS_NO_MEMORY;

    }

    iplist[ret_count] = return_ss;

    ret_count += 1;

    /* we found something */

    status = NT_STATUS_OK;

    /* Multiple names only for DC lookup */

    if (name_type != 0x1c)

      break;

  }

  *return_count = ret_count;

  *return_iplist = talloc_move(mem_ctx, &iplist);

  TALLOC_FREE(ctx);

  endlmhosts(fp);

  return status;

}