#ifndef HEADER_CURL_HTTP_H
#define HEADER_CURL_HTTP_H
/***************************************************************************
 *                                  _   _ ____  _
 *  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"

#include "bufq.h"
#include "dynhds.h"

typedef enum {
  HTTPREQ_GET,
  HTTPREQ_POST,
  HTTPREQ_POST_FORM, /* we make a difference internally */
  HTTPREQ_POST_MIME, /* we make a difference internally */
  HTTPREQ_PUT,
  HTTPREQ_HEAD
} Curl_HttpReq;

/* When redirecting transfers. */
typedef enum {
  FOLLOW_NONE,  /* not used within the function, a placeholder to allow
                   initing to this */
  FOLLOW_FAKE,  /* only records stuff, not actually following */
  FOLLOW_RETRY, /* set if this is a request retry as opposed to a real
                   redirect following */
  FOLLOW_REDIR /* a full true redirect */
} followtype;

#define CURL_HTTP_V1x   (1 << 0)
#define CURL_HTTP_V2x   (1 << 1)
#define CURL_HTTP_V3x   (1 << 2)
/* bitmask of CURL_HTTP_V* values */
typedef unsigned char http_majors;

extern const struct Curl_scheme Curl_scheme_http;
extern const struct Curl_scheme Curl_scheme_https;

#ifndef CURL_DISABLE_HTTP

struct dynhds;

struct http_negotiation {
  unsigned char rcvd_min; /* minimum version seen in responses, 09, 10, 11 */
  http_majors wanted;  /* wanted major versions when talking to server */
  http_majors allowed; /* allowed major versions when talking to server */
  http_majors preferred; /* preferred major version when talking to server */
  BIT(h2_upgrade);  /* Do HTTP Upgrade from 1.1 to 2 */
  BIT(h2_prior_knowledge); /* Directly do HTTP/2 without ALPN/SSL */
  BIT(accept_09); /* Accept an HTTP/0.9 response */
  BIT(only_10); /* When using major version 1x, use only 1.0 */
};

void Curl_http_neg_init(struct Curl_easy *data, struct http_negotiation *neg);

CURLcode Curl_bump_headersize(struct Curl_easy *data,
                              size_t delta,
                              bool connect_only);

/* Header specific functions */
bool Curl_compareheader(const char *headerline,  /* line to check */
                        const char *header,   /* header keyword _with_ colon */
                        const size_t hlen,   /* len of the keyword in bytes */
                        const char *content, /* content string to find */
                        const size_t clen);   /* len of the content in bytes */

char *Curl_copy_header_value(const char *header);

char *Curl_checkProxyheaders(struct Curl_easy *data,
                             const struct connectdata *conn,
                             const char *thisheader,
                             const size_t thislen);

CURLcode Curl_add_timecondition(struct Curl_easy *data, struct dynbuf *req);
CURLcode Curl_add_custom_headers(struct Curl_easy *data, bool is_connect,
                                 int httpversion, struct dynbuf *req);
CURLcode Curl_dynhds_add_custom(struct Curl_easy *data, bool is_connect,
                                struct dynhds *hds);

void Curl_http_to_fold(struct dynbuf *bf);

void Curl_http_method(struct Curl_easy *data,
                      const char **method, Curl_HttpReq *reqp);

/* protocol-specific functions set up to be called by the main engine */
CURLcode Curl_http_setup_conn(struct Curl_easy *data,
                              struct connectdata *conn);
CURLcode Curl_http(struct Curl_easy *data, bool *done);
CURLcode Curl_http_done(struct Curl_easy *data,
                        CURLcode status, bool premature);
CURLcode Curl_http_doing_pollset(struct Curl_easy *data,
                                 struct easy_pollset *ps);
CURLcode Curl_http_perform_pollset(struct Curl_easy *data,
                                   struct easy_pollset *ps);
CURLcode Curl_http_write_resp(struct Curl_easy *data,
                              const char *buf, size_t blen,
                              bool is_eos);
CURLcode Curl_http_write_resp_hd(struct Curl_easy *data,
                                 const char *hd, size_t hdlen,
                                 bool is_eos);

/* These functions are in http.c */
CURLcode Curl_http_input_auth(struct Curl_easy *data, bool proxy,
                              const char *auth);

CURLcode Curl_http_auth_act(struct Curl_easy *data);

/* follow a redirect or not */
CURLcode Curl_http_follow(struct Curl_easy *data, const char *newurl,
                          followtype type);

/* If only the PICKNONE bit is set, there has been a round-trip and we
   selected to use no auth at all. Ie, we actively select no auth, as opposed
   to not having one selected. The other CURLAUTH_* defines are present in the
   public curl/curl.h header. */
#define CURLAUTH_PICKNONE (1 << 30) /* do not use auth */

/* MAX_INITIAL_POST_SIZE indicates the number of bytes that will make the POST
   data get included in the initial data chunk sent to the server. If the
   data is larger than this, it will automatically get split up in multiple
   system calls.

   This value used to be fairly big (100K), but we must take into account that
   if the server rejects the POST due for authentication reasons, this data
   will always be unconditionally sent and thus it may not be larger than can
   always be afforded to send twice.

   It must not be greater than 64K to work on VMS.
*/
#ifndef MAX_INITIAL_POST_SIZE
#define MAX_INITIAL_POST_SIZE (64 * 1024)
#endif

/* EXPECT_100_THRESHOLD is the request body size limit for when libcurl will
 * automatically add an "Expect: 100-continue" header in HTTP requests. When
 * the size is unknown, it will always add it.
 *
 */
#ifndef EXPECT_100_THRESHOLD
#define EXPECT_100_THRESHOLD (1024 * 1024)
#endif

/* MAX_HTTP_RESP_HEADER_SIZE is the maximum size of all response headers
   combined that libcurl allows for a single HTTP response, any HTTP
   version. This count includes CONNECT response headers. */
#define MAX_HTTP_RESP_HEADER_SIZE (300 * 1024)

/* MAX_HTTP_RESP_HEADER_COUNT is the maximum number of response headers that
   libcurl allows for a single HTTP response, including CONNECT and
   redirects. */
#define MAX_HTTP_RESP_HEADER_COUNT 5000

#endif /* CURL_DISABLE_HTTP */

/****************************************************************************
 * HTTP unique setup
 ***************************************************************************/

CURLcode Curl_http_write_resp_hds(struct Curl_easy *data,
                                  const char *buf, size_t blen,
                                  size_t *pconsumed);

/**
 * Curl_http_output_auth() setups the authentication headers for the
 * host/proxy and the correct authentication
 * method. data->state.authdone is set to TRUE when authentication is
 * done.
 *
 * @param data all information about the current transfer
 * @param conn all information about the current connection
 * @param request pointer to the request keyword
 * @param httpreq is the request type
 * @param path pointer to the requested path
 * @param proxytunnel boolean if this is the request setting up a "proxy
 * tunnel"
 *
 * @returns CURLcode
 */
CURLcode
Curl_http_output_auth(struct Curl_easy *data,
                      struct connectdata *conn,
                      const char *request,
                      Curl_HttpReq httpreq,
                      const char *path,
                      bool proxytunnel); /* TRUE if this is the request setting
                                            up the proxy tunnel */

/* Decode HTTP status code string. */
CURLcode Curl_http_decode_status(int *pstatus, const char *s, size_t len);

/**
 * All about a core HTTP request, excluding body and trailers
 */
struct httpreq {
  struct dynhds headers;
  struct dynhds trailers;
  char *scheme;
  char *authority;
  char *path;
  char method[1];
};

/**
 * Create an HTTP request struct.
 */
CURLcode Curl_http_req_make(struct httpreq **preq,
                            const char *method, size_t m_len,
                            const char *scheme, size_t s_len,
                            const char *authority, size_t a_len,
                            const char *path, size_t p_len);

CURLcode Curl_http_req_make2(struct httpreq **preq,
                             const char *method, size_t m_len,
                             CURLU *url, const char *scheme_default);

void Curl_http_req_free(struct httpreq *req);

#define HTTP_PSEUDO_METHOD    ":method"
#define HTTP_PSEUDO_SCHEME    ":scheme"
#define HTTP_PSEUDO_AUTHORITY ":authority"
#define HTTP_PSEUDO_PATH      ":path"
#define HTTP_PSEUDO_STATUS    ":status"

/**
 * Create the list of HTTP/2 headers which represent the request,
 * using HTTP/2 pseudo headers preceding the `req->headers`.
 *
 * Applies the following transformations:
 * - if `authority` is set, any "Host" header is removed.
 * - if `authority` is unset and a "Host" header is present, use
 *   that as `authority` and remove "Host"
 * - removes and Connection header fields as defined in rfc9113 ch. 8.2.2
 * - lower-cases the header field names
 *
 * @param h2_headers will contain the HTTP/2 headers on success
 * @param req        the request to transform
 * @param data       the handle to lookup defaults like ' :scheme' from
 */
CURLcode Curl_http_req_to_h2(struct dynhds *h2_headers,
                             struct httpreq *req, struct Curl_easy *data);

/**
 * All about a core HTTP response, excluding body and trailers
 */
struct http_resp {
  int status;
  char *description;
  struct dynhds headers;
  struct dynhds trailers;
  struct http_resp *prev;
};

/**
 * Create an HTTP response struct.
 */
CURLcode Curl_http_resp_make(struct http_resp **presp,
                             int status,
                             const char *description);

void Curl_http_resp_free(struct http_resp *resp);

#endif /* HEADER_CURL_HTTP_H */
