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

 *                                  _   _ ____  _

 *  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"

#ifndef CURL_DISABLE_HTTP

#include "urldata.h"

#include <curl/curl.h>

#include "http.h"

#include "http1.h"

#include "urlapi-int.h"

#define H1_MAX_URL_LEN   (8*1024)

void Curl_h1_req_parse_init(struct h1_req_parser *parser, size_t max_line_len)

{

  memset(parser, 0, sizeof(*parser));

  parser->max_line_len = max_line_len;

  curlx_dyn_init(&parser->scratch, max_line_len);

}

void Curl_h1_req_parse_free(struct h1_req_parser *parser)

{

  if(parser) {

    Curl_http_req_free(parser->req);

    curlx_dyn_free(&parser->scratch);

    parser->req = NULL;

    parser->done = FALSE;

  }

}

static CURLcode trim_line(struct h1_req_parser *parser, int options)

{

  DEBUGASSERT(parser->line);

  if(parser->line_len) {

    if(parser->line[parser->line_len - 1] == '\n')

      --parser->line_len;

    if(parser->line_len) {

      if(parser->line[parser->line_len - 1] == '\r')

        --parser->line_len;

      else if(options & H1_PARSE_OPT_STRICT)

        return CURLE_URL_MALFORMAT;

    }

    else if(options & H1_PARSE_OPT_STRICT)

      return CURLE_URL_MALFORMAT;

  }

  else if(options & H1_PARSE_OPT_STRICT)

    return CURLE_URL_MALFORMAT;

  if(parser->line_len > parser->max_line_len) {

    return CURLE_URL_MALFORMAT;

  }

  return CURLE_OK;

}

static CURLcode detect_line(struct h1_req_parser *parser,

                            const uint8_t *buf, const size_t buflen,

                            size_t *pnread)

{

  const char *line_end;

  DEBUGASSERT(!parser->line);

  *pnread = 0;

  line_end = memchr(buf, '\n', buflen);

  if(!line_end)

    return CURLE_AGAIN;

  parser->line = (const char *)buf;

  parser->line_len = line_end - parser->line + 1;

  *pnread = parser->line_len;

  return CURLE_OK;

}

static CURLcode next_line(struct h1_req_parser *parser,

                          const uint8_t *buf, const size_t buflen, int options,

                          size_t *pnread)

{

  CURLcode result;

  *pnread = 0;

  if(parser->line) {

    parser->line = NULL;

    parser->line_len = 0;

    curlx_dyn_reset(&parser->scratch);

  }

  result = detect_line(parser, buf, buflen, pnread);

  if(!result) {

    if(curlx_dyn_len(&parser->scratch)) {

      /* append detected line to scratch to have the complete line */

      result = curlx_dyn_addn(&parser->scratch, parser->line,

                              parser->line_len);

      if(result)

        return result;

      parser->line = curlx_dyn_ptr(&parser->scratch);

      parser->line_len = curlx_dyn_len(&parser->scratch);

    }

    result = trim_line(parser, options);

    if(result)

      return result;

  }

  else if(result == CURLE_AGAIN) {

    /* no line end in `buf`, add it to our scratch */

    result = curlx_dyn_addn(&parser->scratch, (const unsigned char *)buf,

                            buflen);

    *pnread = buflen;

  }

  return result;

}

static CURLcode start_req(struct h1_req_parser *parser,

                          const char *scheme_default,

                          const char *custom_method,

                          int options)

{

  const char *p, *m, *target, *hv, *scheme, *authority, *path;

  size_t m_len, target_len, hv_len, scheme_len, authority_len, path_len;

  size_t i;

  CURLU *url = NULL;

  CURLcode result = CURLE_URL_MALFORMAT; /* Use this as default fail */

  DEBUGASSERT(!parser->req);

  /* line must match: "METHOD TARGET HTTP_VERSION" */

  if(custom_method && custom_method[0] &&

     !strncmp(custom_method, parser->line, strlen(custom_method))) {

    p = parser->line + strlen(custom_method);

  }

  else {

    p = memchr(parser->line, ' ', parser->line_len);

    if(!p || p == parser->line)

      goto out;

  }

  m = parser->line;

  m_len = p - parser->line;

  target = p + 1;

  target_len = hv_len = 0;

  hv = NULL;

  /* URL may contain spaces so scan backwards */

  for(i = parser->line_len; i > m_len; --i) {

    if(parser->line[i] == ' ') {

      hv = &parser->line[i + 1];

      hv_len = parser->line_len - i;

      target_len = (hv - target) - 1;

      break;

    }

  }

  /* no SPACE found or empty TARGET or empty HTTP_VERSION */

  if(!target_len || !hv_len)

    goto out;

  (void)hv;

  /* The TARGET can be (rfc 9112, ch. 3.2):

   * origin-form:     path + optional query

   * absolute-form:   absolute URI

   * authority-form:  host+port for CONNECT

   * asterisk-form:   '*' for OPTIONS

   *

   * from TARGET, we derive `scheme` `authority` `path`

   * origin-form            --        --          TARGET

   * absolute-form          URL*      URL*        URL*

   * authority-form         --        TARGET      --

   * asterisk-form          --        --          TARGET

   */

  scheme = authority = path = NULL;

  scheme_len = authority_len = path_len = 0;

  if(target_len == 1 && target[0] == '*') {

    /* asterisk-form */

    path = target;

    path_len = target_len;

  }

  else if(!strncmp("CONNECT", m, m_len)) {

    /* authority-form */

    authority = target;

    authority_len = target_len;

  }

  else if(target[0] == '/') {

    /* origin-form */

    path = target;

    path_len = target_len;

  }

  else {

    /* origin-form OR absolute-form */

    CURLUcode uc;

    char tmp[H1_MAX_URL_LEN];

    /* default, unless we see an absolute URL */

    path = target;

    path_len = target_len;

    /* URL parser wants null-termination */

    if(target_len >= sizeof(tmp))

      goto out;

    memcpy(tmp, target, target_len);

    tmp[target_len] = '\0';

    /* See if treating TARGET as an absolute URL makes sense */

    if(Curl_is_absolute_url(tmp, NULL, 0, FALSE)) {

      unsigned int url_options;

      url = curl_url();

      if(!url) {

        result = CURLE_OUT_OF_MEMORY;

        goto out;

      }

      url_options = (CURLU_NON_SUPPORT_SCHEME|

                     CURLU_PATH_AS_IS|

                     CURLU_NO_DEFAULT_PORT);

      if(!(options & H1_PARSE_OPT_STRICT))

        url_options |= CURLU_ALLOW_SPACE;

      uc = curl_url_set(url, CURLUPART_URL, tmp, url_options);

      if(uc) {

        goto out;

      }

    }

    if(!url && (options & H1_PARSE_OPT_STRICT)) {

      /* we should have an absolute URL or have seen `/` earlier */

      goto out;

    }

  }

  if(url) {

    result = Curl_http_req_make2(&parser->req, m, m_len, url, scheme_default);

  }

  else {

    if(!scheme && scheme_default) {

      scheme = scheme_default;

      scheme_len = strlen(scheme_default);

    }

    result = Curl_http_req_make(&parser->req, m, m_len, scheme, scheme_len,

                                authority, authority_len, path, path_len);

  }

out:

  curl_url_cleanup(url);

  return result;

}

CURLcode Curl_h1_req_parse_read(struct h1_req_parser *parser,

                                const uint8_t *buf, size_t buflen,

                                const char *scheme_default,

                                const char *custom_method,

                                int options, size_t *pnread)

{

  CURLcode result = CURLE_OK;

  size_t nread;

  *pnread = 0;

  while(!parser->done) {

    result = next_line(parser, buf, buflen, options, &nread);

    if(result) {

      if(result == CURLE_AGAIN)

        result = CURLE_OK;

      goto out;

    }

    /* Consume this line */

    *pnread += nread;

    buf += nread;

    buflen -= nread;

    if(!parser->line) {

      /* consumed bytes, but line not complete */

      if(!buflen)

        goto out;

    }

    else if(!parser->req) {

      result = start_req(parser, scheme_default, custom_method, options);

      if(result)

        goto out;

    }

    else if(parser->line_len == 0) {

      /* last, empty line, we are finished */

      if(!parser->req) {

        result = CURLE_URL_MALFORMAT;

        goto out;

      }

      parser->done = TRUE;

      curlx_dyn_reset(&parser->scratch);

      /* last chance adjustments */

    }

    else {

      result = Curl_dynhds_h1_add_line(&parser->req->headers,

                                       parser->line, parser->line_len);

      if(result)

        goto out;

    }

  }

out:

  return result;

}

CURLcode Curl_h1_req_write_head(struct httpreq *req, int http_minor,

                                struct dynbuf *dbuf)

{

  CURLcode result;

  result = curlx_dyn_addf(dbuf, "%s %s%s%s%s HTTP/1.%d\r\n",

                          req->method,

                          req->scheme ? req->scheme : "",

                          req->scheme ? "://" : "",

                          req->authority ? req->authority : "",

                          req->path ? req->path : "",

                          http_minor);

  if(result)

    goto out;

  result = Curl_dynhds_h1_dprint(&req->headers, dbuf);

  if(result)

    goto out;

  result = curlx_dyn_addn(dbuf, STRCONST("\r\n"));

out:

  return result;

}

#endif /* !CURL_DISABLE_HTTP */