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 /* curl stuff */
29 #include <curl/curl.h>
30
31 #include <stdio.h>
32 #include <stdlib.h>
33 #include <string.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 "download_0.data"
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 curl_easy_setopt(hnd, CURLOPT_URL, url);
136 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
137 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
138 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
139
140 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
141
142 /* please be verbose */
143 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
144 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
145
146 #if (CURLPIPE_MULTIPLEX > 0)
147 /* wait for pipe connection to confirm */
148 curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
149 #endif
150 return 0; /* all is good */
151 }
152
153 /* called when there's an incoming push */
server_push_callback(CURL * parent,CURL * easy,size_t num_headers,struct curl_pushheaders * headers,void * userp)154 static int server_push_callback(CURL *parent,
155 CURL *easy,
156 size_t num_headers,
157 struct curl_pushheaders *headers,
158 void *userp)
159 {
160 char *headp;
161 size_t i;
162 int *transfers = (int *)userp;
163 char filename[128];
164 FILE *out;
165 static unsigned int count = 0;
166 int rv;
167
168 (void)parent; /* we have no use for this */
169 curl_msnprintf(filename, sizeof(filename)-1, "push%u", count++);
170
171 /* here's a new stream, save it in a new file for each new push */
172 out = fopen(filename, "wb");
173 if(!out) {
174 /* if we cannot save it, deny it */
175 fprintf(stderr, "Failed to create output file for push\n");
176 rv = CURL_PUSH_DENY;
177 goto out;
178 }
179
180 /* write to this file */
181 curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
182
183 fprintf(stderr, "**** push callback approves stream %u, got %lu headers!\n",
184 count, (unsigned long)num_headers);
185
186 for(i = 0; i < num_headers; i++) {
187 headp = curl_pushheader_bynum(headers, i);
188 fprintf(stderr, "**** header %lu: %s\n", (unsigned long)i, headp);
189 }
190
191 headp = curl_pushheader_byname(headers, ":path");
192 if(headp) {
193 fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */);
194 }
195
196 (*transfers)++; /* one more */
197 rv = CURL_PUSH_OK;
198
199 out:
200 return rv;
201 }
202
203
204 /*
205 * Download a file over HTTP/2, take care of server push.
206 */
main(int argc,char * argv[])207 int main(int argc, char *argv[])
208 {
209 CURL *easy;
210 CURLM *multi_handle;
211 int transfers = 1; /* we start with one */
212 struct CURLMsg *m;
213 const char *url;
214
215 if(argc != 2) {
216 fprintf(stderr, "need URL as argument\n");
217 return 2;
218 }
219 url = argv[1];
220
221 multi_handle = curl_multi_init();
222 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
223 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
224 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
225
226 easy = curl_easy_init();
227 if(setup(easy, url)) {
228 fprintf(stderr, "failed\n");
229 return 1;
230 }
231
232 curl_multi_add_handle(multi_handle, easy);
233 do {
234 int still_running; /* keep number of running handles */
235 CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
236
237 if(still_running)
238 /* wait for activity, timeout or "nothing" */
239 mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
240
241 if(mc)
242 break;
243
244 /*
245 * A little caution when doing server push is that libcurl itself has
246 * created and added one or more easy handles but we need to clean them up
247 * when we are done.
248 */
249 do {
250 int msgq = 0;
251 m = curl_multi_info_read(multi_handle, &msgq);
252 if(m && (m->msg == CURLMSG_DONE)) {
253 CURL *e = m->easy_handle;
254 transfers--;
255 curl_multi_remove_handle(multi_handle, e);
256 curl_easy_cleanup(e);
257 }
258 } while(m);
259
260 } while(transfers); /* as long as we have transfers going */
261
262 curl_multi_cleanup(multi_handle);
263
264 return 0;
265 }
266
