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
29 /* curl stuff */
30 #include <curl/curl.h>
31 #include <curl/mprintf.h>
32
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36
37 /* somewhat unix-specific */
38 #include <sys/time.h>
39 #include <unistd.h>
40
41 #ifndef CURLPIPE_MULTIPLEX
42 #error "too old libcurl, cannot do HTTP/2 server push!"
43 #endif
44
45 static
dump(const char * text,unsigned char * ptr,size_t size,char nohex)46 void dump(const char *text, unsigned char *ptr, size_t size,
47 char nohex)
48 {
49 size_t i;
50 size_t c;
51
52 unsigned int width = 0x10;
53
54 if(nohex)
55 /* without the hex output, we can fit more on screen */
56 width = 0x40;
57
58 fprintf(stderr, "%s, %lu bytes (0x%lx)\n",
59 text, (unsigned long)size, (unsigned long)size);
60
61 for(i = 0; i<size; i += width) {
62
63 fprintf(stderr, "%4.4lx: ", (unsigned long)i);
64
65 if(!nohex) {
66 /* hex not disabled, show it */
67 for(c = 0; c < width; c++)
68 if(i + c < size)
69 fprintf(stderr, "%02x ", ptr[i + c]);
70 else
71 fputs(" ", stderr);
72 }
73
74 for(c = 0; (c < width) && (i + c < size); c++) {
75 /* check for 0D0A; if found, skip past and start a new line of output */
76 if(nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D &&
77 ptr[i + c + 1] == 0x0A) {
78 i += (c + 2 - width);
79 break;
80 }
81 fprintf(stderr, "%c",
82 (ptr[i + c] >= 0x20) && (ptr[i + c]<0x80)?ptr[i + c]:'.');
83 /* check again for 0D0A, to avoid an extra \n if it's at width */
84 if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D &&
85 ptr[i + c + 2] == 0x0A) {
86 i += (c + 3 - width);
87 break;
88 }
89 }
90 fputc('\n', stderr); /* newline */
91 }
92 }
93
94 static
my_trace(CURL * handle,curl_infotype type,char * data,size_t size,void * userp)95 int my_trace(CURL *handle, curl_infotype type,
96 char *data, size_t size,
97 void *userp)
98 {
99 const char *text;
100 (void)handle; /* prevent compiler warning */
101 (void)userp;
102 switch(type) {
103 case CURLINFO_TEXT:
104 fprintf(stderr, "== Info: %s", data);
105 return 0;
106 case CURLINFO_HEADER_OUT:
107 text = "=> Send header";
108 break;
109 case CURLINFO_DATA_OUT:
110 text = "=> Send data";
111 break;
112 case CURLINFO_SSL_DATA_OUT:
113 text = "=> Send SSL data";
114 break;
115 case CURLINFO_HEADER_IN:
116 text = "<= Recv header";
117 break;
118 case CURLINFO_DATA_IN:
119 text = "<= Recv data";
120 break;
121 case CURLINFO_SSL_DATA_IN:
122 text = "<= Recv SSL data";
123 break;
124 default: /* in case a new one is introduced to shock us */
125 return 0;
126 }
127
128 dump(text, (unsigned char *)data, size, 1);
129 return 0;
130 }
131
132 #define OUTPUTFILE "download_0.data"
133
setup(CURL * hnd,const char * url)134 static int setup(CURL *hnd, const char *url)
135 {
136 FILE *out = fopen(OUTPUTFILE, "wb");
137 if(!out)
138 /* failed */
139 return 1;
140
141 curl_easy_setopt(hnd, CURLOPT_URL, url);
142 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
143 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
144 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
145
146 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
147
148 /* please be verbose */
149 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
150 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
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's 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 int rv;
173
174 (void)parent; /* we have no use for this */
175 curl_msnprintf(filename, sizeof(filename)-1, "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 rv = CURL_PUSH_DENY;
183 goto out;
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 rv = CURL_PUSH_OK;
204
205 out:
206 return rv;
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;
220
221 if(argc != 2) {
222 fprintf(stderr, "need URL as argument\n");
223 return 2;
224 }
225 url = argv[1];
226
227 multi_handle = curl_multi_init();
228 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
229 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
230 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
231
232 easy = curl_easy_init();
233 if(setup(easy, url)) {
234 fprintf(stderr, "failed\n");
235 return 1;
236 }
237
238 curl_multi_add_handle(multi_handle, easy);
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 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 return 0;
271 }
272
