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

 *                                  _   _ ____  _

 *  Project                     ___| | | |  _ \| |

 *                             / __| | | | |_) | |

 *                            | (__| |_| |  _ <| |___

 *                             \___|\___/|_| \_\_____|

 *

 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.

 *

 * This software is licensed as described in the file COPYING, which

 * you should have received as part of this distribution. The terms

 * are also available at https://curl.se/docs/copyright.html.

 *

 * You may opt to use, copy, modify, merge, publish, distribute and/or sell

 * copies of the Software, and permit persons to whom the Software is

 * furnished to do so, under the terms of the COPYING file.

 *

 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY

 * KIND, either express or implied.

 *

 * SPDX-License-Identifier: curl

 *

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

#include "curl_setup.h"

#if !defined(CURL_DISABLE_PROXY)

#include <curl/curl.h>

#include "urldata.h"

#include "cfilters.h"

#include "cf-haproxy.h"

#include "curl_log.h"

#include "multiif.h"

/* The last 3 #include files should be in this order */

#include "curl_printf.h"

#include "curl_memory.h"

#include "memdebug.h"

typedef enum {

    HAPROXY_INIT,     /* init/default/no tunnel state */

    HAPROXY_SEND,     /* data_out being sent */

    HAPROXY_DONE      /* all work done */

} haproxy_state;

struct cf_haproxy_ctx {

  int state;

  struct dynbuf data_out;

};

static void cf_haproxy_ctx_reset(struct cf_haproxy_ctx *ctx)

{

  DEBUGASSERT(ctx);

  ctx->state = HAPROXY_INIT;

  Curl_dyn_reset(&ctx->data_out);

}

static void cf_haproxy_ctx_free(struct cf_haproxy_ctx *ctx)

{

  if(ctx) {

    Curl_dyn_free(&ctx->data_out);

    free(ctx);

  }

}

static CURLcode cf_haproxy_date_out_set(struct Curl_cfilter*cf,

                                        struct Curl_easy *data)

{

  struct cf_haproxy_ctx *ctx = cf->ctx;

  CURLcode result;

  const char *tcp_version;

  const char *client_ip;

  DEBUGASSERT(ctx);

  DEBUGASSERT(ctx->state == HAPROXY_INIT);

#ifdef USE_UNIX_SOCKETS

  if(cf->conn->unix_domain_socket)

    /* the buffer is large enough to hold this! */

    result = Curl_dyn_addn(&ctx->data_out, STRCONST("PROXY UNKNOWN\r\n"));

  else {

#endif /* USE_UNIX_SOCKETS */

  /* Emit the correct prefix for IPv6 */

  tcp_version = cf->conn->bits.ipv6 ? "TCP6" : "TCP4";

  if(data->set.str[STRING_HAPROXY_CLIENT_IP])

    client_ip = data->set.str[STRING_HAPROXY_CLIENT_IP];

  else

    client_ip = data->info.conn_primary_ip;

  result = Curl_dyn_addf(&ctx->data_out, "PROXY %s %s %s %i %i\r\n",

                         tcp_version,

                         data->info.conn_local_ip,

                         client_ip,

                         data->info.conn_local_port,

                         data->info.conn_primary_port);

#ifdef USE_UNIX_SOCKETS

  }

#endif /* USE_UNIX_SOCKETS */

  return result;

}

static CURLcode cf_haproxy_connect(struct Curl_cfilter *cf,

                                   struct Curl_easy *data,

                                   bool blocking, bool *done)

{

  struct cf_haproxy_ctx *ctx = cf->ctx;

  CURLcode result;

  size_t len;

  DEBUGASSERT(ctx);

  if(cf->connected) {

    *done = TRUE;

    return CURLE_OK;

  }

  result = cf->next->cft->connect(cf->next, data, blocking, done);

  if(result || !*done)

    return result;

  switch(ctx->state) {

  case HAPROXY_INIT:

    result = cf_haproxy_date_out_set(cf, data);

    if(result)

      goto out;

    ctx->state = HAPROXY_SEND;

    /* FALLTHROUGH */

  case HAPROXY_SEND:

    len = Curl_dyn_len(&ctx->data_out);

    if(len > 0) {

      ssize_t written = Curl_conn_send(data, cf->sockindex,

                                       Curl_dyn_ptr(&ctx->data_out),

                                       len, &result);

      if(written < 0)

        goto out;

      Curl_dyn_tail(&ctx->data_out, len - (size_t)written);

      if(Curl_dyn_len(&ctx->data_out) > 0) {

        result = CURLE_OK;

        goto out;

      }

    }

    ctx->state = HAPROXY_DONE;

    /* FALLTHROUGH */

  default:

    Curl_dyn_free(&ctx->data_out);

    break;

  }

out:

  *done = (!result) && (ctx->state == HAPROXY_DONE);

  cf->connected = *done;

  return result;

}

static void cf_haproxy_destroy(struct Curl_cfilter *cf,

                               struct Curl_easy *data)

{

  (void)data;

  DEBUGF(LOG_CF(data, cf, "destroy"));

  cf_haproxy_ctx_free(cf->ctx);

}

static void cf_haproxy_close(struct Curl_cfilter *cf,

                             struct Curl_easy *data)

{

  DEBUGF(LOG_CF(data, cf, "close"));

  cf->connected = FALSE;

  cf_haproxy_ctx_reset(cf->ctx);

  if(cf->next)

    cf->next->cft->close(cf->next, data);

}

static int cf_haproxy_get_select_socks(struct Curl_cfilter *cf,

                                       struct Curl_easy *data,

                                       curl_socket_t *socks)

{

  int fds;

  fds = cf->next->cft->get_select_socks(cf->next, data, socks);

  if(!fds && cf->next->connected && !cf->connected) {

    /* If we are not connected, but the filter "below" is

     * and not waiting on something, we are sending. */

    socks[0] = Curl_conn_cf_get_socket(cf, data);

    return GETSOCK_WRITESOCK(0);

  }

  return fds;

}

struct Curl_cftype Curl_cft_haproxy = {

  "HAPROXY",

  0,

  0,

  cf_haproxy_destroy,

  cf_haproxy_connect,

  cf_haproxy_close,

  Curl_cf_def_get_host,

  cf_haproxy_get_select_socks,

  Curl_cf_def_data_pending,

  Curl_cf_def_send,

  Curl_cf_def_recv,

  Curl_cf_def_cntrl,

  Curl_cf_def_conn_is_alive,

  Curl_cf_def_conn_keep_alive,

  Curl_cf_def_query,

};

static CURLcode cf_haproxy_create(struct Curl_cfilter **pcf,

                                  struct Curl_easy *data)

{

  struct Curl_cfilter *cf = NULL;

  struct cf_haproxy_ctx *ctx;

  CURLcode result;

  (void)data;

  ctx = calloc(sizeof(*ctx), 1);

  if(!ctx) {

    result = CURLE_OUT_OF_MEMORY;

    goto out;

  }

  ctx->state = HAPROXY_INIT;

  Curl_dyn_init(&ctx->data_out, DYN_HAXPROXY);

  result = Curl_cf_create(&cf, &Curl_cft_haproxy, ctx);

  if(result)

    goto out;

  ctx = NULL;

out:

  cf_haproxy_ctx_free(ctx);

  *pcf = result? NULL : cf;

  return result;

}

CURLcode Curl_cf_haproxy_insert_after(struct Curl_cfilter *cf_at,

                                      struct Curl_easy *data)

{

  struct Curl_cfilter *cf;

  CURLcode result;

  result = cf_haproxy_create(&cf, data);

  if(result)

    goto out;

  Curl_conn_cf_insert_after(cf_at, cf);

out:

  return result;

}

#endif /* !CURL_DISABLE_PROXY */