/* 

   Unix SMB/CIFS implementation.

   general name resolution interface

   Copyright (C) Andrew Tridgell 2005

   Copyright (C) Jelmer Vernooij 2007

   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 "libcli/composite/composite.h"

#include "libcli/resolve/resolve.h"

#include "librpc/gen_ndr/ndr_nbt.h"

#include "system/network.h"

#include "lib/socket/socket.h"

#include "../lib/util/dlinklist.h"

#include "lib/tsocket/tsocket.h"

#include "lib/util/util_net.h"

#undef strcasecmp

struct resolve_state {

  struct resolve_context *ctx;

  struct resolve_method *method;

  uint32_t flags;

  uint16_t port;

  struct nbt_name name;

  struct composite_context *creq;

  struct socket_address **addrs;

  char **names;

};

static struct composite_context *setup_next_method(struct composite_context *c);

struct resolve_context {

  struct resolve_method {

    resolve_name_send_fn send_fn;

    resolve_name_recv_fn recv_fn;

    void *privdata;

    struct resolve_method *prev, *next;

  } *methods;

};

/**

 * Initialize a resolve context

 */

struct resolve_context *resolve_context_init(TALLOC_CTX *mem_ctx)

{

  return talloc_zero(mem_ctx, struct resolve_context);

}

/**

 * Add a resolve method

 */

bool resolve_context_add_method(struct resolve_context *ctx, resolve_name_send_fn send_fn, 

        resolve_name_recv_fn recv_fn, void *userdata)

{

  struct resolve_method *method = talloc_zero(ctx, struct resolve_method);

  if (method == NULL)

    return false;

  method->send_fn = send_fn;

  method->recv_fn = recv_fn;

  method->privdata = userdata;

  DLIST_ADD_END(ctx->methods, method);

  return true;

}

/**

  handle completion of one name resolve method

*/

static void resolve_handler(struct composite_context *creq)

{

  struct composite_context *c = (struct composite_context *)creq->async.private_data;

  struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);

  const struct resolve_method *method = state->method;

  c->status = method->recv_fn(creq, state, &state->addrs, &state->names);

  if (!NT_STATUS_IS_OK(c->status)) {

    state->method = state->method->next;

    state->creq = setup_next_method(c);

    if (state->creq != NULL) {

      return;

    }

  }

  if (!NT_STATUS_IS_OK(c->status)) {

    c->state = COMPOSITE_STATE_ERROR;

  } else {

    c->state = COMPOSITE_STATE_DONE;

  }

  if (c->async.fn) {

    c->async.fn(c);

  }

}

static struct composite_context *setup_next_method(struct composite_context *c)

{

  struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);

  struct composite_context *creq = NULL;

  do {

    if (state->method) {

      creq = state->method->send_fn(c, c->event_ctx,

                  state->method->privdata,

                  state->flags,

                  state->port,

                  &state->name);

    }

    if (creq == NULL && state->method) state->method = state->method->next;

  } while (!creq && state->method);

  if (creq) {

    creq->async.fn = resolve_handler;

    creq->async.private_data = c;

  }

  return creq;

}

/*

  general name resolution - async send

 */

struct composite_context *resolve_name_all_send(struct resolve_context *ctx,

            TALLOC_CTX *mem_ctx,

            uint32_t flags, /* RESOLVE_NAME_FLAG_* */

            uint16_t port,

            struct nbt_name *name,

            struct tevent_context *event_ctx)

{

  struct composite_context *c;

  struct resolve_state *state;

  if (event_ctx == NULL) {

    return NULL;

  }

  c = composite_create(mem_ctx, event_ctx);

  if (c == NULL) return NULL;

  if (composite_nomem(c->event_ctx, c)) return c;

  state = talloc(c, struct resolve_state);

  if (composite_nomem(state, c)) return c;

  c->private_data = state;

  state->flags = flags;

  state->port = port;

  c->status = nbt_name_dup(state, name, &state->name);

  if (!composite_is_ok(c)) return c;

  state->ctx = talloc_reference(state, ctx);

  if (composite_nomem(state->ctx, c)) return c;

  if (is_ipaddress(state->name.name) || 

      strcasecmp(state->name.name, "localhost") == 0) {

    state->addrs = talloc_array(state, struct socket_address *, 2);

    if (composite_nomem(state->addrs, c)) return c;

    state->addrs[0] = socket_address_from_strings(state->addrs, "ip",

                    state->name.name, 0);

    if (composite_nomem(state->addrs[0], c)) return c;

    state->addrs[1] = NULL;

    state->names = talloc_array(state, char *, 2);

    if (composite_nomem(state->names, c)) return c;

    state->names[0] = talloc_strdup(state->names, state->name.name);

    if (composite_nomem(state->names[0], c)) return c;

    state->names[1] = NULL;

    composite_done(c);

    return c;

  }

  state->method = ctx->methods;

  if (state->method == NULL) {

    composite_error(c, NT_STATUS_BAD_NETWORK_NAME);

    return c;

  }

  state->creq = setup_next_method(c);

  if (composite_nomem(state->creq, c)) return c;

  return c;

}

/*

  general name resolution method - recv side

 */

NTSTATUS resolve_name_all_recv(struct composite_context *c,

             TALLOC_CTX *mem_ctx,

             struct socket_address ***addrs,

             char ***names)

{

  NTSTATUS status;

  status = composite_wait(c);

  if (NT_STATUS_IS_OK(status)) {

    struct resolve_state *state = talloc_get_type(c->private_data, struct resolve_state);

    *addrs = talloc_steal(mem_ctx, state->addrs);

    if (names) {

      *names = talloc_steal(mem_ctx, state->names);

    }

  }

  talloc_free(c);

  return status;

}

struct composite_context *resolve_name_ex_send(struct resolve_context *ctx,

                 TALLOC_CTX *mem_ctx,

                 uint32_t flags, /* RESOLVE_NAME_FLAG_* */

                 uint16_t port,

                 struct nbt_name *name,

                 struct tevent_context *event_ctx)

{

  return resolve_name_all_send(ctx, mem_ctx, flags, port, name, event_ctx);

}

struct composite_context *resolve_name_send(struct resolve_context *ctx,

              TALLOC_CTX *mem_ctx,

              struct nbt_name *name,

              struct tevent_context *event_ctx)

{

  return resolve_name_ex_send(ctx, mem_ctx, 0, 0, name, event_ctx);

}

NTSTATUS resolve_name_recv(struct composite_context *c,

         TALLOC_CTX *mem_ctx,

         const char **reply_addr)

{

  NTSTATUS status;

  struct socket_address **addrs = NULL;

  status = resolve_name_all_recv(c, mem_ctx, &addrs, NULL);

  if (NT_STATUS_IS_OK(status)) {

    struct tsocket_address *t_addr = socket_address_to_tsocket_address(addrs, addrs[0]);

    if (!t_addr) {

      return NT_STATUS_NO_MEMORY;

    }

    *reply_addr = tsocket_address_inet_addr_string(t_addr, mem_ctx);

    talloc_free(addrs);

    if (!*reply_addr) {

      return NT_STATUS_NO_MEMORY;

    }

  }

  return status;

}

/*

  receive multiple responses from resolve_name_send()

 */

NTSTATUS resolve_name_multiple_recv(struct composite_context *c,

            TALLOC_CTX *mem_ctx,

            const char ***reply_addrs)

{

  NTSTATUS status;

  struct socket_address **addrs = NULL;

  int i;

  status = resolve_name_all_recv(c, mem_ctx, &addrs, NULL);

  NT_STATUS_NOT_OK_RETURN(status);

  /* count the addresses */

  for (i=0; addrs[i]; i++) ;

  *reply_addrs = talloc_array(mem_ctx, const char *, i+1);

  NT_STATUS_HAVE_NO_MEMORY(*reply_addrs);

  for (i=0; addrs[i]; i++) {

    struct tsocket_address *t_addr = socket_address_to_tsocket_address(addrs, addrs[i]);

    NT_STATUS_HAVE_NO_MEMORY(t_addr);

    (*reply_addrs)[i] = tsocket_address_inet_addr_string(t_addr, *reply_addrs);

    NT_STATUS_HAVE_NO_MEMORY((*reply_addrs)[i]);

  }

  (*reply_addrs)[i] = NULL;

  talloc_free(addrs);

  return status;

}

/*

  general name resolution - sync call

 */

NTSTATUS resolve_name_ex(struct resolve_context *ctx,

       uint32_t flags, /* RESOLVE_NAME_FLAG_* */

       uint16_t port,

       struct nbt_name *name,

       TALLOC_CTX *mem_ctx,

       const char **reply_addr,

       struct tevent_context *ev)

{

  struct composite_context *c = resolve_name_ex_send(ctx, mem_ctx, flags, port, name, ev);

  return resolve_name_recv(c, mem_ctx, reply_addr);

}

/* Initialise a struct nbt_name with a NULL scope */

void make_nbt_name(struct nbt_name *nbt, const char *name, int type)

{

  nbt->name = name;

  nbt->scope = NULL;

  nbt->type = type;

}

/* Initialise a struct nbt_name with a NBT_NAME_CLIENT (0x00) name */

void make_nbt_name_client(struct nbt_name *nbt, const char *name)

{

  make_nbt_name(nbt, name, NBT_NAME_CLIENT);

}

/* Initialise a struct nbt_name with a NBT_NAME_SERVER (0x20) name */

void make_nbt_name_server(struct nbt_name *nbt, const char *name)

{

  make_nbt_name(nbt, name, NBT_NAME_SERVER);

}