/*
  * HTTP protocol for ffmpeg client

  * Copyright (c) 2000, 2001 Fabrice Bellard

  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 
 #include "libavutil/avstring.h"

 #include "avformat.h"

 #include "internal.h"

 #include "network.h"

 #include "http.h"

 #include "os_support.h"

 #include "httpauth.h"

 #include "url.h"

 #include "libavutil/opt.h"

 #if CONFIG_ZLIB
 #include <zlib.h>
 #endif
 

 /* XXX: POST protocol is not completely implemented because ffmpeg uses
    only a subset of it. */

 /* The IO buffer size is unrelated to the max URL size in itself, but needs
  * to be large enough to fit the full request headers (including long
  * path names).
  */
 #define BUFFER_SIZE MAX_URL_SIZE

 #define MAX_REDIRECTS 8
 
 typedef struct {

     const AVClass *class;

     URLContext *hd;
     unsigned char buffer[BUFFER_SIZE], *buf_ptr, *buf_end;
     int line_count;
     int http_code;

     /* Used if "Transfer-Encoding: chunked" otherwise -1. */
     int64_t chunksize;

     int64_t off, end_off, filesize;

     char *location;

     HTTPAuthState auth_state;

     HTTPAuthState proxy_auth_state;

     char *headers;

     char *mime_type;

     char *user_agent;

     char *content_type;

     /* Set if the server correctly handles Connection: close and will close
      * the connection after feeding us the content. */
     int willclose;

     int seekable;           /**< Control seekability, 0 = disable, 1 = enable, -1 = probe. */

     int chunked_post;

     /* A flag which indicates if the end of chunked encoding has been sent. */
     int end_chunked_post;
     /* A flag which indicates we have finished to read POST reply. */
     int end_header;
     /* A flag which indicates if we use persistent connections. */
     int multiple_requests;

     uint8_t *post_data;
     int post_datalen;

     int is_akamai;

     int is_mediagateway;

     char *cookies;          ///< holds newline (\n) delimited Set-Cookie header field values (without the "Set-Cookie: " field name)

     int icy;

     /* how much data was read since the last ICY metadata packet */
     int icy_data_read;
     /* after how many bytes of read data a new metadata packet will be found */
     int icy_metaint;

     char *icy_metadata_headers;
     char *icy_metadata_packet;

 #if CONFIG_ZLIB
     int compressed;
     z_stream inflate_stream;
     uint8_t *inflate_buffer;
 #endif

     AVDictionary *chained_options;

     int send_expect_100;

 } HTTPContext;
 

 #define OFFSET(x) offsetof(HTTPContext, x)

 #define D AV_OPT_FLAG_DECODING_PARAM
 #define E AV_OPT_FLAG_ENCODING_PARAM

 #define DEFAULT_USER_AGENT "Lavf/" AV_STRINGIFY(LIBAVFORMAT_VERSION)

 static const AVOption options[] = {

 {"seekable", "control seekability of connection", OFFSET(seekable), AV_OPT_TYPE_INT, {.i64 = -1}, -1, 1, D },

 {"chunked_post", "use chunked transfer-encoding for posts", OFFSET(chunked_post), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },

 {"headers", "set custom HTTP headers, can override built in default headers", OFFSET(headers), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D|E },

 {"content_type", "set a specific content type for the POST messages", OFFSET(content_type), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D|E },

 {"user_agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = DEFAULT_USER_AGENT}, 0, 0, D },

 {"user-agent", "override User-Agent header", OFFSET(user_agent), AV_OPT_TYPE_STRING, {.str = DEFAULT_USER_AGENT}, 0, 0, D },

 {"multiple_requests", "use persistent connections", OFFSET(multiple_requests), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, D|E },

 {"post_data", "set custom HTTP post data", OFFSET(post_data), AV_OPT_TYPE_BINARY, .flags = D|E },

 {"mime_type", "export the MIME type", OFFSET(mime_type), AV_OPT_TYPE_STRING, {0}, 0, 0, AV_OPT_FLAG_EXPORT | AV_OPT_FLAG_READONLY  },

 {"cookies", "set cookies to be sent in applicable future requests, use newline delimited Set-Cookie HTTP field value syntax", OFFSET(cookies), AV_OPT_TYPE_STRING, {0}, 0, 0, D },

 {"icy", "request ICY metadata", OFFSET(icy), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, D },

 {"icy_metadata_headers", "return ICY metadata headers", OFFSET(icy_metadata_headers), AV_OPT_TYPE_STRING, {0}, 0, 0, AV_OPT_FLAG_EXPORT },
 {"icy_metadata_packet", "return current ICY metadata packet", OFFSET(icy_metadata_packet), AV_OPT_TYPE_STRING, {0}, 0, 0, AV_OPT_FLAG_EXPORT },

 {"auth_type", "HTTP authentication type", OFFSET(auth_state.auth_type), AV_OPT_TYPE_INT, {.i64 = HTTP_AUTH_NONE}, HTTP_AUTH_NONE, HTTP_AUTH_BASIC, D|E, "auth_type" },
 {"none", "No auth method set, autodetect", 0, AV_OPT_TYPE_CONST, {.i64 = HTTP_AUTH_NONE}, 0, 0, D|E, "auth_type" },
 {"basic", "HTTP basic authentication", 0, AV_OPT_TYPE_CONST, {.i64 = HTTP_AUTH_BASIC}, 0, 0, D|E, "auth_type" },

 {"send_expect_100", "Force sending an Expect: 100-continue header for POST", OFFSET(send_expect_100), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, E },

 {"location", "The actual location of the data received", OFFSET(location), AV_OPT_TYPE_STRING, { 0 }, 0, 0, D|E },

 {"offset", "initial byte offset", OFFSET(off), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, D },

 {"end_offset", "try to limit the request to bytes preceding this offset", OFFSET(end_off), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, D },

 {NULL}
 };

 #define HTTP_CLASS(flavor)\
 static const AVClass flavor ## _context_class = {\
     .class_name     = #flavor,\
     .item_name      = av_default_item_name,\
     .option         = options,\
     .version        = LIBAVUTIL_VERSION_INT,\

 }

 HTTP_CLASS(http);
 HTTP_CLASS(https);
 

 static int http_connect(URLContext *h, const char *path, const char *local_path,
                         const char *hoststr, const char *auth,
                         const char *proxyauth, int *new_location);

 void ff_http_init_auth_state(URLContext *dest, const URLContext *src)
 {
     memcpy(&((HTTPContext*)dest->priv_data)->auth_state,
            &((HTTPContext*)src->priv_data)->auth_state, sizeof(HTTPAuthState));

     memcpy(&((HTTPContext*)dest->priv_data)->proxy_auth_state,
            &((HTTPContext*)src->priv_data)->proxy_auth_state,
            sizeof(HTTPAuthState));

 }
 

 /* return non zero if error */

 static int http_open_cnx(URLContext *h, AVDictionary **options)

 {

     const char *path, *proxy_path, *lower_proto = "tcp", *local_path;

     char hostname[1024], hoststr[1024], proto[10];

     char auth[1024], proxyauth[1024] = "";

     char path1[MAX_URL_SIZE];
     char buf[1024], urlbuf[MAX_URL_SIZE];

     int port, use_proxy, err, location_changed = 0, redirects = 0, attempts = 0;

     HTTPAuthType cur_auth_type, cur_proxy_auth_type;

     HTTPContext *s = h->priv_data;
 
     /* fill the dest addr */
  redo:
     /* needed in any case to build the host string */

     av_url_split(proto, sizeof(proto), auth, sizeof(auth),
                  hostname, sizeof(hostname), &port,

                  path1, sizeof(path1), s->location);

     ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, hostname, port, NULL);

     proxy_path = getenv("http_proxy");
     use_proxy = !ff_http_match_no_proxy(getenv("no_proxy"), hostname) &&
                 proxy_path != NULL && av_strstart(proxy_path, "http://", NULL);
 

     if (!strcmp(proto, "https")) {
         lower_proto = "tls";

         use_proxy = 0;

         if (port < 0)
             port = 443;
     }
     if (port < 0)
         port = 80;
 

     if (path1[0] == '\0')
         path = "/";
     else
         path = path1;
     local_path = path;

     if (use_proxy) {

         /* Reassemble the request URL without auth string - we don't
          * want to leak the auth to the proxy. */
         ff_url_join(urlbuf, sizeof(urlbuf), proto, NULL, hostname, port, "%s",
                     path1);
         path = urlbuf;
         av_url_split(NULL, 0, proxyauth, sizeof(proxyauth),
                      hostname, sizeof(hostname), &port, NULL, 0, proxy_path);

     }
 

     ff_url_join(buf, sizeof(buf), lower_proto, NULL, hostname, port, NULL);

     if (!s->hd) {

         err = ffurl_open(&s->hd, buf, AVIO_FLAG_READ_WRITE,

                          &h->interrupt_callback, options);

         if (err < 0)
             goto fail;
     }
 

     cur_auth_type = s->auth_state.auth_type;

     cur_proxy_auth_type = s->auth_state.auth_type;
     if (http_connect(h, path, local_path, hoststr, auth, proxyauth, &location_changed) < 0)

         goto fail;

     attempts++;

     if (s->http_code == 401) {

         if ((cur_auth_type == HTTP_AUTH_NONE || s->auth_state.stale) &&
             s->auth_state.auth_type != HTTP_AUTH_NONE && attempts < 4) {

             ffurl_closep(&s->hd);

             goto redo;
         } else
             goto fail;
     }

     if (s->http_code == 407) {

         if ((cur_proxy_auth_type == HTTP_AUTH_NONE || s->proxy_auth_state.stale) &&
             s->proxy_auth_state.auth_type != HTTP_AUTH_NONE && attempts < 4) {

             ffurl_closep(&s->hd);

             goto redo;
         } else
             goto fail;
     }

     if ((s->http_code == 301 || s->http_code == 302 || s->http_code == 303 || s->http_code == 307)
         && location_changed == 1) {

         /* url moved, get next */

         ffurl_closep(&s->hd);

         if (redirects++ >= MAX_REDIRECTS)

             return AVERROR(EIO);

         /* Restart the authentication process with the new target, which
          * might use a different auth mechanism. */
         memset(&s->auth_state, 0, sizeof(s->auth_state));

         attempts = 0;

         location_changed = 0;
         goto redo;
     }
     return 0;
  fail:

     if (s->hd)

         ffurl_closep(&s->hd);

     return AVERROR(EIO);

 }
 

 int ff_http_do_new_request(URLContext *h, const char *uri)
 {
     HTTPContext *s = h->priv_data;

     AVDictionary *options = NULL;
     int ret;

 
     s->off = 0;

     s->icy_data_read = 0;

     av_free(s->location);
     s->location = av_strdup(uri);
     if (!s->location)
         return AVERROR(ENOMEM);

     av_dict_copy(&options, s->chained_options, 0);
     ret = http_open_cnx(h, &options);
     av_dict_free(&options);
     return ret;

 }
 

 static int http_open(URLContext *h, const char *uri, int flags,
                      AVDictionary **options)

 {

     HTTPContext *s = h->priv_data;

     int ret;

     if( s->seekable == 1 )
         h->is_streamed = 0;
     else
         h->is_streamed = 1;

 
     s->filesize = -1;

     s->location = av_strdup(uri);
     if (!s->location)
         return AVERROR(ENOMEM);

     if (options)
         av_dict_copy(&s->chained_options, *options, 0);

     if (s->headers) {
         int len = strlen(s->headers);
         if (len < 2 || strcmp("\r\n", s->headers + len - 2))

             av_log(h, AV_LOG_WARNING, "No trailing CRLF found in HTTP header.\n");

     }
 

     ret = http_open_cnx(h, options);
     if (ret < 0)
         av_dict_free(&s->chained_options);
     return ret;

 }
 static int http_getc(HTTPContext *s)
 {
     int len;
     if (s->buf_ptr >= s->buf_end) {

         len = ffurl_read(s->hd, s->buffer, BUFFER_SIZE);

         if (len < 0) {

             return len;

         } else if (len == 0) {

             return AVERROR_EOF;

         } else {
             s->buf_ptr = s->buffer;
             s->buf_end = s->buffer + len;
         }
     }
     return *s->buf_ptr++;
 }
 

 static int http_get_line(HTTPContext *s, char *line, int line_size)
 {
     int ch;
     char *q;
 
     q = line;
     for(;;) {
         ch = http_getc(s);
         if (ch < 0)

             return ch;

         if (ch == '\n') {
             /* process line */
             if (q > line && q[-1] == '\r')
                 q--;
             *q = '\0';
 
             return 0;
         } else {
             if ((q - line) < line_size - 1)
                 *q++ = ch;
         }
     }
 }
 

 static int check_http_code(URLContext *h, int http_code, const char *end)
 {
     HTTPContext *s = h->priv_data;
     /* error codes are 4xx and 5xx, but regard 401 as a success, so we
      * don't abort until all headers have been parsed. */
     if (http_code >= 400 && http_code < 600 &&
         (http_code != 401 || s->auth_state.auth_type != HTTP_AUTH_NONE) &&
         (http_code != 407 || s->proxy_auth_state.auth_type != HTTP_AUTH_NONE)) {
         end += strspn(end, SPACE_CHARS);
         av_log(h, AV_LOG_WARNING, "HTTP error %d %s\n", http_code, end);
         return AVERROR(EIO);
     }
     return 0;
 }
 
 static int parse_location(HTTPContext *s, const char *p)
 {
     char redirected_location[MAX_URL_SIZE], *new_loc;
     ff_make_absolute_url(redirected_location, sizeof(redirected_location),
                          s->location, p);
     new_loc = av_strdup(redirected_location);
     if (!new_loc)
         return AVERROR(ENOMEM);
     av_free(s->location);
     s->location = new_loc;
     return 0;
 }
 
 /* "bytes $from-$to/$document_size" */

 static void parse_content_range(URLContext *h, const char *p)

 {
     HTTPContext *s = h->priv_data;
     const char *slash;
 
     if (!strncmp(p, "bytes ", 6)) {
         p += 6;
         s->off = strtoll(p, NULL, 10);
         if ((slash = strchr(p, '/')) && strlen(slash) > 0)
             s->filesize = strtoll(slash+1, NULL, 10);
     }

     if (s->seekable == -1 && (!s->is_akamai || s->filesize != 2147483647))
         h->is_streamed = 0; /* we _can_ in fact seek */

 }
 

 static int parse_content_encoding(URLContext *h, const char *p)

 {
     HTTPContext *s = h->priv_data;
 
     if (!av_strncasecmp(p, "gzip", 4) ||
         !av_strncasecmp(p, "deflate", 7)) {
 #if CONFIG_ZLIB
         s->compressed = 1;
         inflateEnd(&s->inflate_stream);
         if (inflateInit2(&s->inflate_stream, 32 + 15) != Z_OK) {
             av_log(h, AV_LOG_WARNING, "Error during zlib initialisation: %s\n",
                    s->inflate_stream.msg);
             return AVERROR(ENOSYS);
         }
         if (zlibCompileFlags() & (1 << 17)) {
             av_log(h, AV_LOG_WARNING,
                    "Your zlib was compiled without gzip support.\n");
             return AVERROR(ENOSYS);
         }
 #else
         av_log(h, AV_LOG_WARNING,
                "Compressed (%s) content, need zlib with gzip support\n", p);
         return AVERROR(ENOSYS);
 #endif
     } else if (!av_strncasecmp(p, "identity", 8)) {
         // The normal, no-encoding case (although servers shouldn't include
         // the header at all if this is the case).
     } else {
         av_log(h, AV_LOG_WARNING, "Unknown content coding: %s\n", p);
     }
     return 0;
 }
 

 // Concat all Icy- header lines
 static int parse_icy(HTTPContext *s, const char *tag, const char *p)
 {
     int len = 4 + strlen(p) + strlen(tag);

     int is_first = !s->icy_metadata_headers;

     int ret;
 
     if (s->icy_metadata_headers)
         len += strlen(s->icy_metadata_headers);
 
     if ((ret = av_reallocp(&s->icy_metadata_headers, len)) < 0)
         return ret;
 

     if (is_first)
         *s->icy_metadata_headers = '\0';
 

     av_strlcatf(s->icy_metadata_headers, len, "%s: %s\n", tag, p);
 
     return 0;
 }
 

 static int process_line(URLContext *h, char *line, int line_count,
                         int *new_location)
 {
     HTTPContext *s = h->priv_data;

     char *tag, *p, *end;

     int ret;

 
     /* end of header */

     if (line[0] == '\0') {
         s->end_header = 1;

         return 0;

     }

 
     p = line;
     if (line_count == 0) {

         while (!av_isspace(*p) && *p != '\0')

             p++;

         while (av_isspace(*p))

             p++;

         s->http_code = strtol(p, &end, 10);

         av_log(h, AV_LOG_DEBUG, "http_code=%d\n", s->http_code);

         if ((ret = check_http_code(h, s->http_code, end)) < 0)
             return ret;

     } else {
         while (*p != '\0' && *p != ':')
             p++;
         if (*p != ':')
             return 1;
 
         *p = '\0';
         tag = line;
         p++;

         while (av_isspace(*p))

             p++;

         if (!av_strcasecmp(tag, "Location")) {

             if ((ret = parse_location(s, p)) < 0)
                 return ret;

             *new_location = 1;

         } else if (!av_strcasecmp(tag, "Content-Length") && s->filesize == -1) {

             s->filesize = strtoll(p, NULL, 10);

         } else if (!av_strcasecmp(tag, "Content-Range")) {

             parse_content_range(h, p);

         } else if (!av_strcasecmp(tag, "Accept-Ranges") &&

                    !strncmp(p, "bytes", 5) &&
                    s->seekable == -1) {

             h->is_streamed = 0;

         } else if (!av_strcasecmp(tag, "Transfer-Encoding") &&
                    !av_strncasecmp(p, "chunked", 7)) {

             s->filesize = -1;
             s->chunksize = 0;

         } else if (!av_strcasecmp(tag, "WWW-Authenticate")) {

             ff_http_auth_handle_header(&s->auth_state, tag, p);

         } else if (!av_strcasecmp(tag, "Authentication-Info")) {

             ff_http_auth_handle_header(&s->auth_state, tag, p);

         } else if (!av_strcasecmp(tag, "Proxy-Authenticate")) {

             ff_http_auth_handle_header(&s->proxy_auth_state, tag, p);

         } else if (!av_strcasecmp(tag, "Connection")) {

             if (!strcmp(p, "close"))
                 s->willclose = 1;

         } else if (!av_strcasecmp (tag, "Server")) {
             if (!av_strcasecmp (p, "AkamaiGHost")) {
                 s->is_akamai = 1;
             } else if (!av_strncasecmp (p, "MediaGateway", 12)) {
                 s->is_mediagateway = 1;
             }

         } else if (!av_strcasecmp (tag, "Content-Type")) {

             av_free(s->mime_type);
             s->mime_type = av_strdup(p);

         } else if (!av_strcasecmp (tag, "Set-Cookie")) {
             if (!s->cookies) {
                 if (!(s->cookies = av_strdup(p)))
                     return AVERROR(ENOMEM);
             } else {
                 char *tmp = s->cookies;
                 size_t str_size = strlen(tmp) + strlen(p) + 2;
                 if (!(s->cookies = av_malloc(str_size))) {
                     s->cookies = tmp;
                     return AVERROR(ENOMEM);
                 }
                 snprintf(s->cookies, str_size, "%s\n%s", tmp, p);
                 av_free(tmp);
             }

         } else if (!av_strcasecmp (tag, "Icy-MetaInt")) {
             s->icy_metaint = strtoll(p, NULL, 10);
         } else if (!av_strncasecmp(tag, "Icy-", 4)) {

             if ((ret = parse_icy(s, tag, p)) < 0)
                 return ret;

         } else if (!av_strcasecmp(tag, "Content-Encoding")) {

             if ((ret = parse_content_encoding(h, p)) < 0)
                 return ret;

         }
     }
     return 1;
 }
 

 /**
  * Create a string containing cookie values for use as a HTTP cookie header
  * field value for a particular path and domain from the cookie values stored in
  * the HTTP protocol context. The cookie string is stored in *cookies.
  *
  * @return a negative value if an error condition occurred, 0 otherwise
  */
 static int get_cookies(HTTPContext *s, char **cookies, const char *path,
                        const char *domain)
 {
     // cookie strings will look like Set-Cookie header field values.  Multiple
     // Set-Cookie fields will result in multiple values delimited by a newline
     int ret = 0;
     char *next, *cookie, *set_cookies = av_strdup(s->cookies), *cset_cookies = set_cookies;
 
     if (!set_cookies) return AVERROR(EINVAL);
 
     *cookies = NULL;
     while ((cookie = av_strtok(set_cookies, "\n", &next))) {
         int domain_offset = 0;
         char *param, *next_param, *cdomain = NULL, *cpath = NULL, *cvalue = NULL;
         set_cookies = NULL;
 
         while ((param = av_strtok(cookie, "; ", &next_param))) {
             cookie = NULL;
             if        (!av_strncasecmp("path=",   param, 5)) {

                 av_free(cpath);

                 cpath = av_strdup(&param[5]);
             } else if (!av_strncasecmp("domain=", param, 7)) {

                 // if the cookie specifies a sub-domain, skip the leading dot thereby
                 // supporting URLs that point to sub-domains and the master domain
                 int leading_dot = (param[7] == '.');

                 av_free(cdomain);

                 cdomain = av_strdup(&param[7+leading_dot]);

             } else if (!av_strncasecmp("secure",  param, 6) ||
                        !av_strncasecmp("comment", param, 7) ||
                        !av_strncasecmp("max-age", param, 7) ||
                        !av_strncasecmp("version", param, 7)) {
                 // ignore Comment, Max-Age, Secure and Version
             } else {

                 av_free(cvalue);

                 cvalue = av_strdup(param);
             }
         }

         if (!cdomain)
             cdomain = av_strdup(domain);

 
         // ensure all of the necessary values are valid
         if (!cdomain || !cpath || !cvalue) {
             av_log(s, AV_LOG_WARNING,
                    "Invalid cookie found, no value, path or domain specified\n");
             goto done_cookie;
         }
 
         // check if the request path matches the cookie path
         if (av_strncasecmp(path, cpath, strlen(cpath)))
             goto done_cookie;
 
         // the domain should be at least the size of our cookie domain
         domain_offset = strlen(domain) - strlen(cdomain);
         if (domain_offset < 0)
             goto done_cookie;
 
         // match the cookie domain
         if (av_strcasecmp(&domain[domain_offset], cdomain))
             goto done_cookie;
 
         // cookie parameters match, so copy the value
         if (!*cookies) {
             if (!(*cookies = av_strdup(cvalue))) {
                 ret = AVERROR(ENOMEM);
                 goto done_cookie;
             }
         } else {
             char *tmp = *cookies;
             size_t str_size = strlen(cvalue) + strlen(*cookies) + 3;
             if (!(*cookies = av_malloc(str_size))) {
                 ret = AVERROR(ENOMEM);
                 goto done_cookie;
             }
             snprintf(*cookies, str_size, "%s; %s", tmp, cvalue);
             av_free(tmp);
         }
 
         done_cookie:
         av_free(cdomain);
         av_free(cpath);
         av_free(cvalue);
         if (ret < 0) {
             if (*cookies) av_freep(cookies);
             av_free(cset_cookies);
             return ret;
         }
     }
 
     av_free(cset_cookies);
 
     return 0;
 }
 

 static inline int has_header(const char *str, const char *header)
 {
     /* header + 2 to skip over CRLF prefix. (make sure you have one!) */

     if (!str)
         return 0;

     return av_stristart(str, header + 2, NULL) || av_stristr(str, header);
 }
 

 static int http_read_header(URLContext *h, int *new_location)
 {
     HTTPContext *s = h->priv_data;

     char line[MAX_URL_SIZE];

     int err = 0;
 

     s->chunksize = -1;
 

     for (;;) {

         if ((err = http_get_line(s, line, sizeof(line))) < 0)
             return err;

         av_log(h, AV_LOG_DEBUG, "header='%s'\n", line);

 
         err = process_line(h, line, s->line_count, new_location);
         if (err < 0)
             return err;
         if (err == 0)
             break;
         s->line_count++;
     }
 

     if (s->seekable == -1 && s->is_mediagateway && s->filesize == 2000000000)
         h->is_streamed = 1; /* we can in fact _not_ seek */
 

     return err;
 }
 

 static int http_connect(URLContext *h, const char *path, const char *local_path,
                         const char *hoststr, const char *auth,
                         const char *proxyauth, int *new_location)

 {
     HTTPContext *s = h->priv_data;

     int post, err;

     char headers[4096] = "";

     char *authstr = NULL, *proxyauthstr = NULL;

     int64_t off = s->off;

     int len = 0;

     const char *method;

     int send_expect_100 = 0;

 
 
     /* send http header */

     post = h->flags & AVIO_FLAG_WRITE;

 
     if (s->post_data) {
         /* force POST method and disable chunked encoding when
          * custom HTTP post data is set */
         post = 1;
         s->chunked_post = 0;
     }
 

     method = post ? "POST" : "GET";
     authstr = ff_http_auth_create_response(&s->auth_state, auth, local_path,
                                            method);
     proxyauthstr = ff_http_auth_create_response(&s->proxy_auth_state, proxyauth,
                                                 local_path, method);

     if (post && !s->post_data) {
         send_expect_100 = s->send_expect_100;
         /* The user has supplied authentication but we don't know the auth type,
          * send Expect: 100-continue to get the 401 response including the
          * WWW-Authenticate header, or an 100 continue if no auth actually
          * is needed. */

         if (auth && *auth &&
             s->auth_state.auth_type == HTTP_AUTH_NONE &&

             s->http_code != 401)
             send_expect_100 = 1;
     }

 
     /* set default headers if needed */
     if (!has_header(s->headers, "\r\nUser-Agent: "))

         len += av_strlcatf(headers + len, sizeof(headers) - len,

                            "User-Agent: %s\r\n", s->user_agent);

     if (!has_header(s->headers, "\r\nAccept: "))
         len += av_strlcpy(headers + len, "Accept: */*\r\n",
                           sizeof(headers) - len);

     // Note: we send this on purpose even when s->off is 0 when we're probing,

     // since it allows us to detect more reliably if a (non-conforming)
     // server supports seeking by analysing the reply headers.

     if (!has_header(s->headers, "\r\nRange: ") && !post && (s->off > 0 || s->end_off || s->seekable == -1)) {

         len += av_strlcatf(headers + len, sizeof(headers) - len,

                            "Range: bytes=%"PRId64"-", s->off);

         if (s->end_off)

             len += av_strlcatf(headers + len, sizeof(headers) - len,

                                "%"PRId64, s->end_off - 1);

         len += av_strlcpy(headers + len, "\r\n",
                           sizeof(headers) - len);
     }

     if (send_expect_100 && !has_header(s->headers, "\r\nExpect: "))
         len += av_strlcatf(headers + len, sizeof(headers) - len,
                            "Expect: 100-continue\r\n");

 
     if (!has_header(s->headers, "\r\nConnection: ")) {
         if (s->multiple_requests) {
             len += av_strlcpy(headers + len, "Connection: keep-alive\r\n",
                               sizeof(headers) - len);
         } else {
             len += av_strlcpy(headers + len, "Connection: close\r\n",
                               sizeof(headers) - len);
         }
     }
 

     if (!has_header(s->headers, "\r\nHost: "))
         len += av_strlcatf(headers + len, sizeof(headers) - len,
                            "Host: %s\r\n", hoststr);

     if (!has_header(s->headers, "\r\nContent-Length: ") && s->post_data)
         len += av_strlcatf(headers + len, sizeof(headers) - len,
                            "Content-Length: %d\r\n", s->post_datalen);

     if (!has_header(s->headers, "\r\nContent-Type: ") && s->content_type)
         len += av_strlcatf(headers + len, sizeof(headers) - len,
                            "Content-Type: %s\r\n", s->content_type);

     if (!has_header(s->headers, "\r\nCookie: ") && s->cookies) {
         char *cookies = NULL;
         if (!get_cookies(s, &cookies, path, hoststr)) {
             len += av_strlcatf(headers + len, sizeof(headers) - len,
                                "Cookie: %s\r\n", cookies);
             av_free(cookies);
         }
     }

     if (!has_header(s->headers, "\r\nIcy-MetaData: ") && s->icy) {
         len += av_strlcatf(headers + len, sizeof(headers) - len,
                            "Icy-MetaData: %d\r\n", 1);
     }

 
     /* now add in custom headers */

     if (s->headers)
         av_strlcpy(headers + len, s->headers, sizeof(headers) - len);

     snprintf(s->buffer, sizeof(s->buffer),
              "%s %s HTTP/1.1\r\n"

              "%s"

              "%s"

              "%s"

              "%s%s"

              "\r\n",

              method,

              path,

              post && s->chunked_post ? "Transfer-Encoding: chunked\r\n" : "",

              headers,

              authstr ? authstr : "",
              proxyauthstr ? "Proxy-" : "", proxyauthstr ? proxyauthstr : "");

     av_freep(&authstr);

     av_freep(&proxyauthstr);

 
     av_log(h, AV_LOG_DEBUG, "request: %s\n", s->buffer);
 

     if ((err = ffurl_write(s->hd, s->buffer, strlen(s->buffer))) < 0)
         return err;

     if (s->post_data)
         if ((err = ffurl_write(s->hd, s->post_data, s->post_datalen)) < 0)
             return err;

 
     /* init input buffer */
     s->buf_ptr = s->buffer;
     s->buf_end = s->buffer;
     s->line_count = 0;
     s->off = 0;

     s->icy_data_read = 0;

     s->filesize = -1;

     s->willclose = 0;

     s->end_chunked_post = 0;

     s->end_header = 0;

     if (post && !s->post_data && !send_expect_100) {

         /* Pretend that it did work. We didn't read any header yet, since
          * we've still to send the POST data, but the code calling this
          * function will check http_code after we return. */
         s->http_code = 200;

         return 0;
     }
 
     /* wait for header */

     err = http_read_header(h, new_location);
     if (err < 0)
         return err;

 
     return (off == s->off) ? 0 : -1;
 }
 
 

 static int http_buf_read(URLContext *h, uint8_t *buf, int size)

 {
     HTTPContext *s = h->priv_data;
     int len;

     /* read bytes from input buffer first */
     len = s->buf_end - s->buf_ptr;
     if (len > 0) {
         if (len > size)
             len = size;
         memcpy(buf, s->buf_ptr, len);
         s->buf_ptr += len;
     } else {
         if (!s->willclose && s->filesize >= 0 && s->off >= s->filesize)
             return AVERROR_EOF;
         len = ffurl_read(s->hd, buf, size);
     }
     if (len > 0) {
         s->off += len;
         if (s->chunksize > 0)
             s->chunksize -= len;
     }
     return len;
 }
 

 #if CONFIG_ZLIB
 #define DECOMPRESS_BUF_SIZE (256 * 1024)
 static int http_buf_read_compressed(URLContext *h, uint8_t *buf, int size)
 {
     HTTPContext *s = h->priv_data;
     int ret;
 
     if (!s->inflate_buffer) {
         s->inflate_buffer = av_malloc(DECOMPRESS_BUF_SIZE);
         if (!s->inflate_buffer)
             return AVERROR(ENOMEM);
     }
 
     if (s->inflate_stream.avail_in == 0) {
         int read = http_buf_read(h, s->inflate_buffer, DECOMPRESS_BUF_SIZE);
         if (read <= 0)
             return read;
         s->inflate_stream.next_in  = s->inflate_buffer;
         s->inflate_stream.avail_in = read;
     }
 
     s->inflate_stream.avail_out = size;
     s->inflate_stream.next_out  = buf;
 
     ret = inflate(&s->inflate_stream, Z_SYNC_FLUSH);
     if (ret != Z_OK && ret != Z_STREAM_END)

         av_log(h, AV_LOG_WARNING, "inflate return value: %d, %s\n", ret, s->inflate_stream.msg);

 
     return size - s->inflate_stream.avail_out;
 }
 #endif
 

 static int http_read_stream(URLContext *h, uint8_t *buf, int size)

 {
     HTTPContext *s = h->priv_data;

     int err, new_location;
 

     if (!s->hd)
         return AVERROR_EOF;

     if (s->end_chunked_post && !s->end_header) {
         err = http_read_header(h, &new_location);
         if (err < 0)
             return err;

     }

     if (s->chunksize >= 0) {
         if (!s->chunksize) {
             char line[32];
 
             for(;;) {
                 do {

                     if ((err = http_get_line(s, line, sizeof(line))) < 0)
                         return err;

                 } while (!*line);    /* skip CR LF from last chunk */
 
                 s->chunksize = strtoll(line, NULL, 16);
 

                 av_dlog(NULL, "Chunked encoding data size: %"PRId64"'\n", s->chunksize);

 
                 if (!s->chunksize)
                     return 0;
                 break;
             }
         }
         size = FFMIN(size, s->chunksize);
     }

 #if CONFIG_ZLIB
     if (s->compressed)
         return http_buf_read_compressed(h, buf, size);
 #endif
     return http_buf_read(h, buf, size);
 }
 
 // Like http_read_stream(), but no short reads.
 // Assumes partial reads are an error.
 static int http_read_stream_all(URLContext *h, uint8_t *buf, int size)
 {
     int pos = 0;
     while (pos < size) {
         int len = http_read_stream(h, buf + pos, size - pos);
         if (len < 0)
             return len;
         pos += len;
     }
     return pos;
 }
 

 static int store_icy(URLContext *h, int size)
 {
     HTTPContext *s = h->priv_data;
     /* until next metadata packet */
     int remaining = s->icy_metaint - s->icy_data_read;
 
     if (remaining < 0)
         return AVERROR_INVALIDDATA;
 
     if (!remaining) {
         // The metadata packet is variable sized. It has a 1 byte header
         // which sets the length of the packet (divided by 16). If it's 0,
         // the metadata doesn't change. After the packet, icy_metaint bytes
         // of normal data follow.
         uint8_t ch;
         int len = http_read_stream_all(h, &ch, 1);
         if (len < 0)
             return len;
         if (ch > 0) {
             char data[255 * 16 + 1];
             int ret;
             len = ch * 16;
             ret = http_read_stream_all(h, data, len);
             if (ret < 0)
                 return ret;
             data[len + 1] = 0;
             if ((ret = av_opt_set(s, "icy_metadata_packet", data, 0)) < 0)
                 return ret;
         }
         s->icy_data_read = 0;
         remaining = s->icy_metaint;
     }
 
     return FFMIN(size, remaining);
 }
 

 static int http_read(URLContext *h, uint8_t *buf, int size)
 {
     HTTPContext *s = h->priv_data;
 

     if (s->icy_metaint > 0) {

         size = store_icy(h, size);
         if (size < 0)
             return size;

     }

     size = http_read_stream(h, buf, size);
     if (size > 0)
         s->icy_data_read += size;
     return size;

 }
 
 /* used only when posting data */

 static int http_write(URLContext *h, const uint8_t *buf, int size)

 {

     char temp[11] = "";  /* 32-bit hex + CRLF + nul */

     int ret;
     char crlf[] = "\r\n";

     HTTPContext *s = h->priv_data;

     if (!s->chunked_post) {

         /* non-chunked data is sent without any special encoding */

         return ffurl_write(s->hd, buf, size);

     }
 
     /* silently ignore zero-size data since chunk encoding that would
      * signal EOF */
     if (size > 0) {
         /* upload data using chunked encoding */

         snprintf(temp, sizeof(temp), "%x\r\n", size);

         if ((ret = ffurl_write(s->hd, temp, strlen(temp))) < 0 ||
             (ret = ffurl_write(s->hd, buf, size)) < 0 ||
             (ret = ffurl_write(s->hd, crlf, sizeof(crlf) - 1)) < 0)

             return ret;
     }
     return size;

 }
 

 static int http_shutdown(URLContext *h, int flags)

 {

     int ret = 0;
     char footer[] = "0\r\n\r\n";

     HTTPContext *s = h->priv_data;

 
     /* signal end of chunked encoding if used */

     if ((flags & AVIO_FLAG_WRITE) && s->chunked_post) {

         ret = ffurl_write(s->hd, footer, sizeof(footer) - 1);

         ret = ret > 0 ? 0 : ret;

         s->end_chunked_post = 1;
     }
 
     return ret;
 }
 
 static int http_close(URLContext *h)
 {
     int ret = 0;
     HTTPContext *s = h->priv_data;
 

 #if CONFIG_ZLIB
     inflateEnd(&s->inflate_stream);
     av_freep(&s->inflate_buffer);
 #endif
 

     if (!s->end_chunked_post) {
         /* Close the write direction by sending the end of chunked encoding. */
         ret = http_shutdown(h, h->flags);

     }
 

     if (s->hd)

         ffurl_closep(&s->hd);

     av_dict_free(&s->chained_options);

     return ret;

 }
 

 static int64_t http_seek(URLContext *h, int64_t off, int whence)

 {
     HTTPContext *s = h->priv_data;
     URLContext *old_hd = s->hd;

     int64_t old_off = s->off;

     uint8_t old_buf[BUFFER_SIZE];

     int old_buf_size, ret;

     AVDictionary *options = NULL;

 
     if (whence == AVSEEK_SIZE)
         return s->filesize;

     else if ((whence == SEEK_CUR && off == 0) ||
              (whence == SEEK_SET && off == s->off))

         return s->off;

     else if ((s->filesize == -1 && whence == SEEK_END) || h->is_streamed)

         return AVERROR(ENOSYS);

 
     /* we save the old context in case the seek fails */

     old_buf_size = s->buf_end - s->buf_ptr;
     memcpy(old_buf, s->buf_ptr, old_buf_size);

     s->hd = NULL;
     if (whence == SEEK_CUR)
         off += s->off;
     else if (whence == SEEK_END)
         off += s->filesize;
     s->off = off;
 
     /* if it fails, continue on old connection */

     av_dict_copy(&options, s->chained_options, 0);

     if ((ret = http_open_cnx(h, &options)) < 0) {

         av_dict_free(&options);

         memcpy(s->buffer, old_buf, old_buf_size);
         s->buf_ptr = s->buffer;
         s->buf_end = s->buffer + old_buf_size;

         s->hd = old_hd;
         s->off = old_off;

         return ret;

     }

     av_dict_free(&options);

     ffurl_close(old_hd);

     return off;
 }
 

 static int
 http_get_file_handle(URLContext *h)
 {
     HTTPContext *s = h->priv_data;

     return ffurl_get_file_handle(s->hd);

 }
 

 #if CONFIG_HTTP_PROTOCOL

 URLProtocol ff_http_protocol = {

     .name                = "http",

     .url_open2           = http_open,

     .url_read            = http_read,
     .url_write           = http_write,
     .url_seek            = http_seek,
     .url_close           = http_close,

     .url_get_file_handle = http_get_file_handle,

     .url_shutdown        = http_shutdown,

     .priv_data_size      = sizeof(HTTPContext),

     .priv_data_class     = &http_context_class,

     .flags               = URL_PROTOCOL_FLAG_NETWORK,

 };

 #endif
 #if CONFIG_HTTPS_PROTOCOL
 URLProtocol ff_https_protocol = {
     .name                = "https",

     .url_open2           = http_open,

     .url_read            = http_read,
     .url_write           = http_write,
     .url_seek            = http_seek,
     .url_close           = http_close,
     .url_get_file_handle = http_get_file_handle,

     .url_shutdown        = http_shutdown,

     .priv_data_size      = sizeof(HTTPContext),

     .priv_data_class     = &https_context_class,

     .flags               = URL_PROTOCOL_FLAG_NETWORK,

 };
 #endif

 
 #if CONFIG_HTTPPROXY_PROTOCOL
 static int http_proxy_close(URLContext *h)
 {
     HTTPContext *s = h->priv_data;
     if (s->hd)

         ffurl_closep(&s->hd);

     return 0;
 }
 
 static int http_proxy_open(URLContext *h, const char *uri, int flags)
 {
     HTTPContext *s = h->priv_data;
     char hostname[1024], hoststr[1024];
     char auth[1024], pathbuf[1024], *path;

     char lower_url[100];

     int port, ret = 0, attempts = 0;

     HTTPAuthType cur_auth_type;
     char *authstr;

     int new_loc;

     if( s->seekable == 1 )
         h->is_streamed = 0;
     else
         h->is_streamed = 1;

 
     av_url_split(NULL, 0, auth, sizeof(auth), hostname, sizeof(hostname), &port,
                  pathbuf, sizeof(pathbuf), uri);
     ff_url_join(hoststr, sizeof(hoststr), NULL, NULL, hostname, port, NULL);
     path = pathbuf;
     if (*path == '/')
         path++;
 
     ff_url_join(lower_url, sizeof(lower_url), "tcp", NULL, hostname, port,
                 NULL);
 redo:
     ret = ffurl_open(&s->hd, lower_url, AVIO_FLAG_READ_WRITE,
                      &h->interrupt_callback, NULL);
     if (ret < 0)
         return ret;
 
     authstr = ff_http_auth_create_response(&s->proxy_auth_state, auth,
                                            path, "CONNECT");
     snprintf(s->buffer, sizeof(s->buffer),
              "CONNECT %s HTTP/1.1\r\n"
              "Host: %s\r\n"
              "Connection: close\r\n"
              "%s%s"
              "\r\n",
              path,
              hoststr,
              authstr ? "Proxy-" : "", authstr ? authstr : "");
     av_freep(&authstr);
 
     if ((ret = ffurl_write(s->hd, s->buffer, strlen(s->buffer))) < 0)
         goto fail;
 
     s->buf_ptr = s->buffer;
     s->buf_end = s->buffer;
     s->line_count = 0;
     s->filesize = -1;
     cur_auth_type = s->proxy_auth_state.auth_type;
 

     /* Note: This uses buffering, potentially reading more than the
      * HTTP header. If tunneling a protocol where the server starts
      * the conversation, we might buffer part of that here, too.
      * Reading that requires using the proper ffurl_read() function
      * on this URLContext, not using the fd directly (as the tls
      * protocol does). This shouldn't be an issue for tls though,
      * since the client starts the conversation there, so there
      * is no extra data that we might buffer up here.
      */
     ret = http_read_header(h, &new_loc);
     if (ret < 0)
         goto fail;

     attempts++;
     if (s->http_code == 407 &&
         (cur_auth_type == HTTP_AUTH_NONE || s->proxy_auth_state.stale) &&
         s->proxy_auth_state.auth_type != HTTP_AUTH_NONE && attempts < 2) {

         ffurl_closep(&s->hd);

         goto redo;
     }
 
     if (s->http_code < 400)
         return 0;
     ret = AVERROR(EIO);
 
 fail:
     http_proxy_close(h);
     return ret;
 }
 
 static int http_proxy_write(URLContext *h, const uint8_t *buf, int size)
 {
     HTTPContext *s = h->priv_data;
     return ffurl_write(s->hd, buf, size);
 }
 
 URLProtocol ff_httpproxy_protocol = {
     .name                = "httpproxy",
     .url_open            = http_proxy_open,
     .url_read            = http_buf_read,
     .url_write           = http_proxy_write,
     .url_close           = http_proxy_close,
     .url_get_file_handle = http_get_file_handle,
     .priv_data_size      = sizeof(HTTPContext),

     .flags               = URL_PROTOCOL_FLAG_NETWORK,

 };
 #endif