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 /* FALLTHROUGH */
104 default: /* in case a new one is introduced to shock us */
105 return 0;
106
107 case CURLINFO_HEADER_OUT:
108 text = "=> Send header";
109 break;
110 case CURLINFO_DATA_OUT:
111 text = "=> Send data";
112 break;
113 case CURLINFO_SSL_DATA_OUT:
114 text = "=> Send SSL data";
115 break;
116 case CURLINFO_HEADER_IN:
117 text = "<= Recv header";
118 break;
119 case CURLINFO_DATA_IN:
120 text = "<= Recv data";
121 break;
122 case CURLINFO_SSL_DATA_IN:
123 text = "<= Recv SSL data";
124 break;
125 }
126
127 dump(text, (unsigned char *)data, size, 1);
128 return 0;
129 }
130
131 #define OUTPUTFILE "dl"
132
setup(CURL * hnd,const char * url)133 static int setup(CURL *hnd, const char *url)
134 {
135 FILE *out = fopen(OUTPUTFILE, "wb");
136 if(!out)
137 /* failed */
138 return 1;
139
140 /* write to this file */
141 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
142
143 /* set the same URL */
144 curl_easy_setopt(hnd, CURLOPT_URL, url);
145
146 /* please be verbose */
147 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
148 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
149
150 /* HTTP/2 please */
151 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
152
153 /* we use a self-signed test server, skip verification during debugging */
154 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
155 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
156
157 #if (CURLPIPE_MULTIPLEX > 0)
158 /* wait for pipe connection to confirm */
159 curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
160 #endif
161 return 0; /* all is good */
162 }
163
164 /* called when there is an incoming push */
server_push_callback(CURL * parent,CURL * easy,size_t num_headers,struct curl_pushheaders * headers,void * userp)165 static int server_push_callback(CURL *parent,
166 CURL *easy,
167 size_t num_headers,
168 struct curl_pushheaders *headers,
169 void *userp)
170 {
171 char *headp;
172 size_t i;
173 int *transfers = (int *)userp;
174 char filename[128];
175 FILE *out;
176 static unsigned int count = 0;
177
178 (void)parent; /* we have no use for this */
179
180 snprintf(filename, 128, "push%u", count++);
181
182 /* here's a new stream, save it in a new file for each new push */
183 out = fopen(filename, "wb");
184 if(!out) {
185 /* if we cannot save it, deny it */
186 fprintf(stderr, "Failed to create output file for push\n");
187 return CURL_PUSH_DENY;
188 }
189
190 /* write to this file */
191 curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
192
193 fprintf(stderr, "**** push callback approves stream %u, got %lu headers!\n",
194 count, (unsigned long)num_headers);
195
196 for(i = 0; i<num_headers; i++) {
197 headp = curl_pushheader_bynum(headers, i);
198 fprintf(stderr, "**** header %lu: %s\n", (unsigned long)i, headp);
199 }
200
201 headp = curl_pushheader_byname(headers, ":path");
202 if(headp) {
203 fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */);
204 }
205
206 (*transfers)++; /* one more */
207 return CURL_PUSH_OK;
208 }
209
210
211 /*
212 * Download a file over HTTP/2, take care of server push.
213 */
main(int argc,char * argv[])214 int main(int argc, char *argv[])
215 {
216 CURL *easy;
217 CURLM *multi_handle;
218 int transfers = 1; /* we start with one */
219 struct CURLMsg *m;
220 const char *url = "https://localhost:8443/index.html";
221
222 if(argc == 2)
223 url = argv[1];
224
225 /* init a multi stack */
226 multi_handle = curl_multi_init();
227
228 easy = curl_easy_init();
229
230 /* set options */
231 if(setup(easy, url)) {
232 fprintf(stderr, "failed\n");
233 return 1;
234 }
235
236 /* add the easy transfer */
237 curl_multi_add_handle(multi_handle, easy);
238
239 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
240 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
241 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
242
243 do {
244 int still_running; /* keep number of running handles */
245 CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
246
247 if(still_running)
248 /* wait for activity, timeout or "nothing" */
249 mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
250
251 if(mc)
252 break;
253
254 /*
255 * A little caution when doing server push is that libcurl itself has
256 * created and added one or more easy handles but we need to clean them up
257 * when we are done.
258 */
259
260 do {
261 int msgq = 0;
262 m = curl_multi_info_read(multi_handle, &msgq);
263 if(m && (m->msg == CURLMSG_DONE)) {
264 CURL *e = m->easy_handle;
265 transfers--;
266 curl_multi_remove_handle(multi_handle, e);
267 curl_easy_cleanup(e);
268 }
269 } while(m);
270
271 } while(transfers); /* as long as we have transfers going */
272
273 curl_multi_cleanup(multi_handle);
274
275
276 return 0;
277 }
278