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