1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24 /* <DESC>
25 * HTTP/2 server push
26 * </DESC>
27 */
28 #include <stdio.h>
29 #include <stdlib.h>
30 #include <string.h>
31
32 /* somewhat unix-specific */
33 #include <sys/time.h>
34 #include <unistd.h>
35
36 /* curl stuff */
37 #include <curl/curl.h>
38
39 #ifndef CURLPIPE_MULTIPLEX
40 #error "too old libcurl, cannot do HTTP/2 server push!"
41 #endif
42
43 static
dump(const char * text,unsigned char * ptr,size_t size,char nohex)44 void dump(const char *text, unsigned char *ptr, size_t size,
45 char nohex)
46 {
47 size_t i;
48 size_t c;
49
50 unsigned int width = 0x10;
51
52 if(nohex)
53 /* without the hex output, we can fit more on screen */
54 width = 0x40;
55
56 fprintf(stderr, "%s, %lu bytes (0x%lx)\n",
57 text, (unsigned long)size, (unsigned long)size);
58
59 for(i = 0; i<size; i += width) {
60
61 fprintf(stderr, "%4.4lx: ", (unsigned long)i);
62
63 if(!nohex) {
64 /* hex not disabled, show it */
65 for(c = 0; c < width; c++)
66 if(i + c < size)
67 fprintf(stderr, "%02x ", ptr[i + c]);
68 else
69 fputs(" ", stderr);
70 }
71
72 for(c = 0; (c < width) && (i + c < size); c++) {
73 /* check for 0D0A; if found, skip past and start a new line of output */
74 if(nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D &&
75 ptr[i + c + 1] == 0x0A) {
76 i += (c + 2 - width);
77 break;
78 }
79 fprintf(stderr, "%c",
80 (ptr[i + c] >= 0x20) && (ptr[i + c]<0x80)?ptr[i + c]:'.');
81 /* check again for 0D0A, to avoid an extra \n if it's at width */
82 if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D &&
83 ptr[i + c + 2] == 0x0A) {
84 i += (c + 3 - width);
85 break;
86 }
87 }
88 fputc('\n', stderr); /* newline */
89 }
90 }
91
92 static
my_trace(CURL * handle,curl_infotype type,char * data,size_t size,void * userp)93 int my_trace(CURL *handle, curl_infotype type,
94 char *data, size_t size,
95 void *userp)
96 {
97 const char *text;
98 (void)handle; /* prevent compiler warning */
99 (void)userp;
100 switch(type) {
101 case CURLINFO_TEXT:
102 fprintf(stderr, "== Info: %s", data);
103 return 0;
104 case CURLINFO_HEADER_OUT:
105 text = "=> Send header";
106 break;
107 case CURLINFO_DATA_OUT:
108 text = "=> Send data";
109 break;
110 case CURLINFO_SSL_DATA_OUT:
111 text = "=> Send SSL data";
112 break;
113 case CURLINFO_HEADER_IN:
114 text = "<= Recv header";
115 break;
116 case CURLINFO_DATA_IN:
117 text = "<= Recv data";
118 break;
119 case CURLINFO_SSL_DATA_IN:
120 text = "<= Recv SSL data";
121 break;
122 default: /* in case a new one is introduced to shock us */
123 return 0;
124 }
125
126 dump(text, (unsigned char *)data, size, 1);
127 return 0;
128 }
129
130 #define OUTPUTFILE "dl"
131
setup(CURL * hnd,const char * url)132 static int setup(CURL *hnd, const char *url)
133 {
134 FILE *out = fopen(OUTPUTFILE, "wb");
135 if(!out)
136 /* failed */
137 return 1;
138
139 /* write to this file */
140 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
141
142 /* set the same URL */
143 curl_easy_setopt(hnd, CURLOPT_URL, url);
144
145 /* please be verbose */
146 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
147 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
148
149 /* HTTP/2 please */
150 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
151
152 /* we use a self-signed test server, skip verification during debugging */
153 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
154 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
155
156 #if (CURLPIPE_MULTIPLEX > 0)
157 /* wait for pipe connection to confirm */
158 curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
159 #endif
160 return 0; /* all is good */
161 }
162
163 /* called when there is an incoming push */
server_push_callback(CURL * parent,CURL * easy,size_t num_headers,struct curl_pushheaders * headers,void * userp)164 static int server_push_callback(CURL *parent,
165 CURL *easy,
166 size_t num_headers,
167 struct curl_pushheaders *headers,
168 void *userp)
169 {
170 char *headp;
171 size_t i;
172 int *transfers = (int *)userp;
173 char filename[128];
174 FILE *out;
175 static unsigned int count = 0;
176
177 (void)parent; /* we have no use for this */
178
179 snprintf(filename, 128, "push%u", count++);
180
181 /* here's a new stream, save it in a new file for each new push */
182 out = fopen(filename, "wb");
183 if(!out) {
184 /* if we cannot save it, deny it */
185 fprintf(stderr, "Failed to create output file for push\n");
186 return CURL_PUSH_DENY;
187 }
188
189 /* write to this file */
190 curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
191
192 fprintf(stderr, "**** push callback approves stream %u, got %lu headers!\n",
193 count, (unsigned long)num_headers);
194
195 for(i = 0; i<num_headers; i++) {
196 headp = curl_pushheader_bynum(headers, i);
197 fprintf(stderr, "**** header %lu: %s\n", (unsigned long)i, headp);
198 }
199
200 headp = curl_pushheader_byname(headers, ":path");
201 if(headp) {
202 fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */);
203 }
204
205 (*transfers)++; /* one more */
206 return CURL_PUSH_OK;
207 }
208
209
210 /*
211 * Download a file over HTTP/2, take care of server push.
212 */
main(int argc,char * argv[])213 int main(int argc, char *argv[])
214 {
215 CURL *easy;
216 CURLM *multi_handle;
217 int transfers = 1; /* we start with one */
218 struct CURLMsg *m;
219 const char *url = "https://localhost:8443/index.html";
220
221 if(argc == 2)
222 url = argv[1];
223
224 /* init a multi stack */
225 multi_handle = curl_multi_init();
226
227 easy = curl_easy_init();
228
229 /* set options */
230 if(setup(easy, url)) {
231 fprintf(stderr, "failed\n");
232 return 1;
233 }
234
235 /* add the easy transfer */
236 curl_multi_add_handle(multi_handle, easy);
237
238 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
239 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
240 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
241
242 do {
243 int still_running; /* keep number of running handles */
244 CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
245
246 if(still_running)
247 /* wait for activity, timeout or "nothing" */
248 mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
249
250 if(mc)
251 break;
252
253 /*
254 * A little caution when doing server push is that libcurl itself has
255 * created and added one or more easy handles but we need to clean them up
256 * when we are done.
257 */
258
259 do {
260 int msgq = 0;
261 m = curl_multi_info_read(multi_handle, &msgq);
262 if(m && (m->msg == CURLMSG_DONE)) {
263 CURL *e = m->easy_handle;
264 transfers--;
265 curl_multi_remove_handle(multi_handle, e);
266 curl_easy_cleanup(e);
267 }
268 } while(m);
269
270 } while(transfers); /* as long as we have transfers going */
271
272 curl_multi_cleanup(multi_handle);
273
274
275 return 0;
276 }
277