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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2017, 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.haxx.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.
*
***************************************************************************/
/* <DESC>
* HTTP/2 server push
* </DESC>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* somewhat unix-specific */
#include <sys/time.h>
#include <unistd.h>
/* curl stuff */
#include <curl/curl.h>
#ifndef CURLPIPE_MULTIPLEX
#error "too old libcurl, can't do HTTP/2 server push!"
#endif
static
void dump(const char *text, unsigned char *ptr, size_t size,
char nohex)
{
size_t i;
size_t c;
unsigned int width = 0x10;
if(nohex)
/* without the hex output, we can fit more on screen */
width = 0x40;
fprintf(stderr, "%s, %lu bytes (0x%lx)\n",
text, (unsigned long)size, (unsigned long)size);
for(i = 0; i<size; i += width) {
fprintf(stderr, "%4.4lx: ", (unsigned long)i);
if(!nohex) {
/* hex not disabled, show it */
for(c = 0; c < width; c++)
if(i + c < size)
fprintf(stderr, "%02x ", ptr[i + c]);
else
fputs(" ", stderr);
}
for(c = 0; (c < width) && (i + c < size); c++) {
/* check for 0D0A; if found, skip past and start a new line of output */
if(nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D &&
ptr[i + c + 1] == 0x0A) {
i += (c + 2 - width);
break;
}
fprintf(stderr, "%c",
(ptr[i + c] >= 0x20) && (ptr[i + c]<0x80)?ptr[i + c]:'.');
/* check again for 0D0A, to avoid an extra \n if it's at width */
if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D &&
ptr[i + c + 2] == 0x0A) {
i += (c + 3 - width);
break;
}
}
fputc('\n', stderr); /* newline */
}
}
static
int my_trace(CURL *handle, curl_infotype type,
char *data, size_t size,
void *userp)
{
const char *text;
(void)handle; /* prevent compiler warning */
(void)userp;
switch(type) {
case CURLINFO_TEXT:
fprintf(stderr, "== Info: %s", data);
/* FALLTHROUGH */
default: /* in case a new one is introduced to shock us */
return 0;
case CURLINFO_HEADER_OUT:
text = "=> Send header";
break;
case CURLINFO_DATA_OUT:
text = "=> Send data";
break;
case CURLINFO_SSL_DATA_OUT:
text = "=> Send SSL data";
break;
case CURLINFO_HEADER_IN:
text = "<= Recv header";
break;
case CURLINFO_DATA_IN:
text = "<= Recv data";
break;
case CURLINFO_SSL_DATA_IN:
text = "<= Recv SSL data";
break;
}
dump(text, (unsigned char *)data, size, 1);
return 0;
}
#define OUTPUTFILE "dl"
static void setup(CURL *hnd)
{
FILE *out = fopen(OUTPUTFILE, "wb");
/* write to this file */
curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
/* set the same URL */
curl_easy_setopt(hnd, CURLOPT_URL, "https://localhost:8443/index.html");
/* please be verbose */
curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
/* HTTP/2 please */
curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
/* we use a self-signed test server, skip verification during debugging */
curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
#if (CURLPIPE_MULTIPLEX > 0)
/* wait for pipe connection to confirm */
curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
#endif
}
/* called when there's an incoming push */
static int server_push_callback(CURL *parent,
CURL *easy,
size_t num_headers,
struct curl_pushheaders *headers,
void *userp)
{
char *headp;
size_t i;
int *transfers = (int *)userp;
char filename[128];
FILE *out;
static unsigned int count = 0;
(void)parent; /* we have no use for this */
snprintf(filename, 128, "push%u", count++);
/* here's a new stream, save it in a new file for each new push */
out = fopen(filename, "wb");
/* write to this file */
curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
fprintf(stderr, "**** push callback approves stream %u, got %lu headers!\n",
count, (unsigned long)num_headers);
for(i = 0; i<num_headers; i++) {
headp = curl_pushheader_bynum(headers, i);
fprintf(stderr, "**** header %lu: %s\n", (unsigned long)i, headp);
}
headp = curl_pushheader_byname(headers, ":path");
if(headp) {
fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */);
}
(*transfers)++; /* one more */
return CURL_PUSH_OK;
}
/*
* Download a file over HTTP/2, take care of server push.
*/
int main(void)
{
CURL *easy;
CURLM *multi_handle;
int still_running; /* keep number of running handles */
int transfers = 1; /* we start with one */
struct CURLMsg *m;
/* init a multi stack */
multi_handle = curl_multi_init();
easy = curl_easy_init();
/* set options */
setup(easy);
/* add the easy transfer */
curl_multi_add_handle(multi_handle, easy);
curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
/* we start some action by calling perform right away */
curl_multi_perform(multi_handle, &still_running);
do {
struct timeval timeout;
int rc; /* select() return code */
CURLMcode mc; /* curl_multi_fdset() return code */
fd_set fdread;
fd_set fdwrite;
fd_set fdexcep;
int maxfd = -1;
long curl_timeo = -1;
FD_ZERO(&fdread);
FD_ZERO(&fdwrite);
FD_ZERO(&fdexcep);
/* set a suitable timeout to play around with */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
curl_multi_timeout(multi_handle, &curl_timeo);
if(curl_timeo >= 0) {
timeout.tv_sec = curl_timeo / 1000;
if(timeout.tv_sec > 1)
timeout.tv_sec = 1;
else
timeout.tv_usec = (curl_timeo % 1000) * 1000;
}
/* get file descriptors from the transfers */
mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
if(mc != CURLM_OK) {
fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
break;
}
/* On success the value of maxfd is guaranteed to be >= -1. We call
select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
to sleep 100ms, which is the minimum suggested value in the
curl_multi_fdset() doc. */
if(maxfd == -1) {
#ifdef _WIN32
Sleep(100);
rc = 0;
#else
/* Portable sleep for platforms other than Windows. */
struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
rc = select(0, NULL, NULL, NULL, &wait);
#endif
}
else {
/* Note that on some platforms 'timeout' may be modified by select().
If you need access to the original value save a copy beforehand. */
rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
}
switch(rc) {
case -1:
/* select error */
break;
case 0:
default:
/* timeout or readable/writable sockets */
curl_multi_perform(multi_handle, &still_running);
break;
}
/*
* A little caution when doing server push is that libcurl itself has
* created and added one or more easy handles but we need to clean them up
* when we are done.
*/
do {
int msgq = 0;;
m = curl_multi_info_read(multi_handle, &msgq);
if(m && (m->msg == CURLMSG_DONE)) {
CURL *e = m->easy_handle;
transfers--;
curl_multi_remove_handle(multi_handle, e);
curl_easy_cleanup(e);
}
} while(m);
} while(transfers); /* as long as we have transfers going */
curl_multi_cleanup(multi_handle);
return 0;
}
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