curl/lib/cfilters.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2022, 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"

#include "urldata.h"
#include "strerror.h"
#include "cfilters.h"
#include "connect.h"
#include "url.h" /* for Curl_safefree() */
#include "sendf.h"
#include "sockaddr.h" /* required for Curl_sockaddr_storage */
#include "multiif.h"
#include "progress.h"
#include "warnless.h"
#include "http_proxy.h"
#include "socks.h"
#include "vtls/vtls.h"

/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"

#ifndef ARRAYSIZE
#define ARRAYSIZE(A) (sizeof(A)/sizeof((A)[0]))
#endif

#ifdef DEBUGBUILD
static void cf_debug(struct Curl_easy *data, const char *fname,
                     struct connectdata *conn, int index, CURLcode result)
{
  struct Curl_cfilter *cf;
  char chain[128];
  size_t offset = 0, len;

  for(cf = conn->cfilter[index]; cf; cf = cf->next) {
    len = strlen(cf->cft->name);
    if(offset + len + 2 > sizeof(chain))
      break;
    if(offset) {
      chain[offset++] = '.';
    }
    strcpy(chain + offset, cf->cft->name);
    offset += len;
  }
  chain[offset] = 0;
  infof(data, "%s(handle=%p, cfilter%d=[%s]) -> %d",
        fname, data, index, chain, result);
}

#endif

void Curl_cf_def_destroy(struct Curl_cfilter *cf, struct Curl_easy *data)
{
  (void)cf;
  (void)data;
}

CURLcode Curl_cf_def_setup(struct Curl_cfilter *cf,
                           struct Curl_easy *data,
                           const struct Curl_dns_entry *remotehost)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->setup(cf->next, data, remotehost);
}

void     Curl_cf_def_attach_data(struct Curl_cfilter *cf,
                                 struct Curl_easy *data)
{
  (void)cf;
  (void)data;
}

void     Curl_cf_def_detach_data(struct Curl_cfilter *cf,
                                 struct Curl_easy *data)
{
  (void)cf;
  (void)data;
}

void Curl_cf_def_close(struct Curl_cfilter *cf, struct Curl_easy *data)
{
  DEBUGASSERT(cf->next);
  cf->connected = FALSE;
  cf->next->cft->close(cf->next, data);
}

CURLcode Curl_cf_def_connect(struct Curl_cfilter *cf,
                             struct Curl_easy *data,
                             bool blocking, bool *done)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->connect(cf->next, data, blocking, done);
}

int Curl_cf_def_get_select_socks(struct Curl_cfilter *cf,
                                 struct Curl_easy *data,
                                 curl_socket_t *socks)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->get_select_socks(cf->next, data, socks);
}

bool Curl_cf_def_data_pending(struct Curl_cfilter *cf,
                              const struct Curl_easy *data)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->has_data_pending(cf->next, data);
}

ssize_t  Curl_cf_def_send(struct Curl_cfilter *cf, struct Curl_easy *data,
                          const void *buf, size_t len, CURLcode *err)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->do_send(cf->next, data, buf, len, err);
}

ssize_t  Curl_cf_def_recv(struct Curl_cfilter *cf, struct Curl_easy *data,
                          char *buf, size_t len, CURLcode *err)
{
  DEBUGASSERT(cf->next);
  return cf->next->cft->do_recv(cf->next, data, buf, len, err);
}

void Curl_cfilter_destroy(struct Curl_easy *data,
                          struct connectdata *conn, int index)
{
  struct Curl_cfilter *cfn, *cf = conn->cfilter[index];

  if(cf) {
    DEBUGF(infof(data, "Curl_cfilter_destroy(handle=%p, connection=%ld, "
                 "index=%d)", data, conn->connection_id, index));
    conn->cfilter[index] = NULL;
    while(cf) {
      cfn = cf->next;
      cf->cft->destroy(cf, data);
      free(cf);
      cf = cfn;
    }
  }
}

void Curl_cfilter_close(struct Curl_easy *data,
                        struct connectdata *conn, int index)
{
  struct Curl_cfilter *cf;

  DEBUGASSERT(conn);
  /* it is valid to call that without filters being present */
  cf = conn->cfilter[index];
  if(cf) {
    DEBUGF(infof(data, "Curl_cfilter_close(handle=%p, index=%d)",
           data, index));
    cf->cft->close(cf, data);
  }
}

ssize_t Curl_cfilter_recv(struct Curl_easy *data, int num, char *buf,
                          size_t len, CURLcode *code)
{
  struct Curl_cfilter *cf;
  ssize_t nread;

  DEBUGASSERT(data);
  DEBUGASSERT(data->conn);
  cf = data->conn->cfilter[num];
  while(cf && !cf->connected) {
    cf = cf->next;
  }
  if(cf) {
    nread = cf->cft->do_recv(cf, data, buf, len, code);
    /* DEBUGF(infof(data, "Curl_cfilter_recv(handle=%p, index=%d)"
           "-> %ld, err=%d", data, num, nread, *code));*/
    return nread;
  }
  failf(data, "no filter connected, conn=%ld, sockindex=%d",
        data->conn->connection_id, num);
  *code = CURLE_FAILED_INIT;
  return -1;
}

ssize_t Curl_cfilter_send(struct Curl_easy *data, int num,
                          const void *mem, size_t len, CURLcode *code)
{
  struct Curl_cfilter *cf;
  ssize_t nwritten;

  DEBUGASSERT(data);
  DEBUGASSERT(data->conn);
  cf = data->conn->cfilter[num];
  while(cf && !cf->connected) {
    cf = cf->next;
  }
  if(cf) {
    nwritten = cf->cft->do_send(cf, data, mem, len, code);
    /* DEBUGF(infof(data, "Curl_cfilter_send(handle=%p, index=%d, len=%ld)"
           " -> %ld, err=%d", data, num, len, nwritten, *code));*/
    return nwritten;
  }
  failf(data, "no filter connected, conn=%ld, sockindex=%d",
        data->conn->connection_id, num);
  *code = CURLE_FAILED_INIT;
  return -1;
}

CURLcode Curl_cfilter_create(struct Curl_cfilter **pcf,
                             struct Curl_easy *data,
                             struct connectdata *conn,
                             int sockindex,
                             const struct Curl_cftype *cft,
                             void *ctx)
{
  struct Curl_cfilter *cf;
  CURLcode result = CURLE_OUT_OF_MEMORY;

  (void)data;
  (void)conn;
  DEBUGASSERT(cft);
  cf = calloc(sizeof(*cf), 1);
  if(!cf)
    goto out;

  cf->cft = cft;
  cf->conn = conn;
  cf->sockindex = sockindex;
  cf->ctx = ctx;
  result = CURLE_OK;
out:
  *pcf = cf;
  return result;
}

void Curl_cfilter_add(struct Curl_easy *data, struct connectdata *conn,
                      int index, struct Curl_cfilter *cf)
{
  (void)data;
  DEBUGF(infof(data, "Curl_cfilter_add(conn=%ld, index=%d, filter=%s)",
               conn->connection_id, index, cf->cft->name));

  cf->next = conn->cfilter[index];
  cf->conn = conn;
  cf->sockindex = index;
  conn->cfilter[index] = cf;
}

CURLcode Curl_cfilter_setup(struct Curl_easy *data,
                            struct connectdata *conn, int sockindex,
                            const struct Curl_dns_entry *remotehost,
                            int ssl_mode)
{
  struct Curl_cfilter *cf;
  CURLcode result;

  DEBUGASSERT(data);
  /* If no filter is set, we have the "default" setup of connection filters.
   * The filter chain from botton to top will be:
   * - SOCKET       socket filter for outgoing connection to remotehost
   * if http_proxy tunneling is engaged:
   *    - SSL                 if proxytype is CURLPROXY_HTTPS
   *    - HTTP_PROXY_TUNNEL
   * otherwise, if socks_proxy is engaged:
   *    - SOCKS_PROXY_TUNNEL
   * - SSL          if conn->handler has PROTOPT_SSL
   */
  if(!conn->cfilter[sockindex]) {
    DEBUGF(infof(data, "Curl_cfilter_setup(conn #%ld, index=%d)",
           conn->connection_id, sockindex));
    result = Curl_cfilter_socket_set(data, conn, sockindex);
    if(result)
      goto out;

#ifndef CURL_DISABLE_PROXY
    if(conn->bits.socksproxy) {
      result = Curl_cfilter_socks_proxy_add(data, conn, sockindex);
      if(result)
        goto out;
    }

    if(conn->bits.httpproxy) {
#ifdef USE_SSL
      if(conn->http_proxy.proxytype == CURLPROXY_HTTPS) {
        result = Curl_cfilter_ssl_proxy_add(data, conn, sockindex);
        if(result)
          goto out;
      }
#endif /* USE_SSL */

#if !defined(CURL_DISABLE_HTTP)
      if(conn->bits.tunnel_proxy) {
        result = Curl_cfilter_http_proxy_add(data, conn, sockindex);
        if(result)
          goto out;
      }
#endif /* !CURL_DISABLE_HTTP */
    }
#endif /* !CURL_DISABLE_PROXY */

#ifdef USE_SSL
    if(ssl_mode == CURL_CF_SSL_ENABLE
      || (ssl_mode != CURL_CF_SSL_DISABLE
           && conn->handler->flags & PROTOPT_SSL)) {
      result = Curl_cfilter_ssl_add(data, conn, sockindex);
      if(result)
        goto out;
    }
#else
    (void)ssl_mode;
#endif /* USE_SSL */
  }
  DEBUGASSERT(conn->cfilter[sockindex]);
  cf = data->conn->cfilter[sockindex];
  result = cf->cft->setup(cf, data, remotehost);
out:
  DEBUGF(cf_debug(data, "Curl_cfilter_setup", conn, sockindex, result));
  return result;
}

CURLcode Curl_cfilter_connect(struct Curl_easy *data,
                              struct connectdata *conn, int sockindex,
                              bool blocking, bool *done)
{
  struct Curl_cfilter *cf;
  CURLcode result;

  DEBUGASSERT(data);

  cf = conn->cfilter[sockindex];
  DEBUGASSERT(cf);
  result = cf->cft->connect(cf, data, blocking, done);

  DEBUGF(infof(data, "Curl_cfilter_connect(handle=%p, index=%d, block=%d) "
         "-> %d, done=%d", data, sockindex, blocking, result, *done));
  return result;
}

bool Curl_cfilter_is_connected(struct Curl_easy *data,
                               struct connectdata *conn, int sockindex)
{
  struct Curl_cfilter *cf;

  (void)data;
  cf = conn->cfilter[sockindex];
  return cf && cf->connected;
}

bool Curl_cfilter_data_pending(const struct Curl_easy *data,
                               struct connectdata *conn, int sockindex)
{
  struct Curl_cfilter *cf;

  DEBUGASSERT(data);
  cf = conn->cfilter[sockindex];
  while(cf && !cf->connected) {
    cf = cf->next;
  }
  if(cf) {
    return cf->cft->has_data_pending(cf, data);
  }
  return FALSE;
}

int Curl_cfilter_get_select_socks(struct Curl_easy *data,
                                  struct connectdata *conn, int sockindex,
                                  curl_socket_t *socks)
{
  struct Curl_cfilter *cf;

  DEBUGASSERT(data);
  cf = conn->cfilter[sockindex];
  if(cf) {
    return cf->cft->get_select_socks(cf, data, socks);
  }
  return GETSOCK_BLANK;
}

void Curl_cfilter_attach_data(struct connectdata *conn,
                              struct Curl_easy *data)
{
  size_t i;
  struct Curl_cfilter *cf;

  for(i = 0; i < ARRAYSIZE(conn->cfilter); ++i) {
    cf = conn->cfilter[i];
    if(cf) {
      DEBUGF(infof(data, "Curl_cfilter_attach(handle=%p, connection=%ld, "
                   "index=%d)", data, conn->connection_id, i));
      while(cf) {
        cf->cft->attach_data(cf, data);
        cf = cf->next;
      }
    }
  }
}

void Curl_cfilter_detach_data(struct connectdata *conn,
                              struct Curl_easy *data)
{
  size_t i;
  struct Curl_cfilter *cf;

  for(i = 0; i < ARRAYSIZE(conn->cfilter); ++i) {
    cf = conn->cfilter[i];
    if(cf) {
      DEBUGF(infof(data, "Curl_cfilter_detach(handle=%p, connection=%ld, "
                   "index=%d)", data, conn->connection_id, i));
      while(cf) {
        cf->cft->detach_data(cf, data);
        cf = cf->next;
      }
    }
  }
}