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