1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, 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 ***************************************************************************/
22 /* <DESC>
23 * HTTP/2 server push
24 * </DESC>
25 */
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29
30 /* somewhat unix-specific */
31 #include <sys/time.h>
32 #include <unistd.h>
33
34 /* curl stuff */
35 #include <curl/curl.h>
36
37 #ifndef CURLPIPE_MULTIPLEX
38 #error "too old libcurl, can't do HTTP/2 server push!"
39 #endif
40
41 static
dump(const char * text,unsigned char * ptr,size_t size,char nohex)42 void dump(const char *text, unsigned char *ptr, size_t size,
43 char nohex)
44 {
45 size_t i;
46 size_t c;
47
48 unsigned int width = 0x10;
49
50 if(nohex)
51 /* without the hex output, we can fit more on screen */
52 width = 0x40;
53
54 fprintf(stderr, "%s, %lu bytes (0x%lx)\n",
55 text, (unsigned long)size, (unsigned long)size);
56
57 for(i = 0; i<size; i += width) {
58
59 fprintf(stderr, "%4.4lx: ", (unsigned long)i);
60
61 if(!nohex) {
62 /* hex not disabled, show it */
63 for(c = 0; c < width; c++)
64 if(i + c < size)
65 fprintf(stderr, "%02x ", ptr[i + c]);
66 else
67 fputs(" ", stderr);
68 }
69
70 for(c = 0; (c < width) && (i + c < size); c++) {
71 /* check for 0D0A; if found, skip past and start a new line of output */
72 if(nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D &&
73 ptr[i + c + 1] == 0x0A) {
74 i += (c + 2 - width);
75 break;
76 }
77 fprintf(stderr, "%c",
78 (ptr[i + c] >= 0x20) && (ptr[i + c]<0x80)?ptr[i + c]:'.');
79 /* check again for 0D0A, to avoid an extra \n if it's at width */
80 if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D &&
81 ptr[i + c + 2] == 0x0A) {
82 i += (c + 3 - width);
83 break;
84 }
85 }
86 fputc('\n', stderr); /* newline */
87 }
88 }
89
90 static
my_trace(CURL * handle,curl_infotype type,char * data,size_t size,void * userp)91 int my_trace(CURL *handle, curl_infotype type,
92 char *data, size_t size,
93 void *userp)
94 {
95 const char *text;
96 (void)handle; /* prevent compiler warning */
97 (void)userp;
98 switch(type) {
99 case CURLINFO_TEXT:
100 fprintf(stderr, "== Info: %s", data);
101 /* FALLTHROUGH */
102 default: /* in case a new one is introduced to shock us */
103 return 0;
104
105 case CURLINFO_HEADER_OUT:
106 text = "=> Send header";
107 break;
108 case CURLINFO_DATA_OUT:
109 text = "=> Send data";
110 break;
111 case CURLINFO_SSL_DATA_OUT:
112 text = "=> Send SSL data";
113 break;
114 case CURLINFO_HEADER_IN:
115 text = "<= Recv header";
116 break;
117 case CURLINFO_DATA_IN:
118 text = "<= Recv data";
119 break;
120 case CURLINFO_SSL_DATA_IN:
121 text = "<= Recv SSL data";
122 break;
123 }
124
125 dump(text, (unsigned char *)data, size, 1);
126 return 0;
127 }
128
129 #define OUTPUTFILE "dl"
130
setup(CURL * hnd)131 static int setup(CURL *hnd)
132 {
133 FILE *out = fopen(OUTPUTFILE, "wb");
134 if(!out)
135 /* failed */
136 return 1;
137
138 /* write to this file */
139 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out);
140
141 /* set the same URL */
142 curl_easy_setopt(hnd, CURLOPT_URL, "https://localhost:8443/index.html");
143
144 /* please be verbose */
145 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L);
146 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace);
147
148 /* HTTP/2 please */
149 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0);
150
151 /* we use a self-signed test server, skip verification during debugging */
152 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L);
153 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L);
154
155 #if (CURLPIPE_MULTIPLEX > 0)
156 /* wait for pipe connection to confirm */
157 curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L);
158 #endif
159 return 0; /* all is good */
160 }
161
162 /* called when there's an incoming push */
server_push_callback(CURL * parent,CURL * easy,size_t num_headers,struct curl_pushheaders * headers,void * userp)163 static int server_push_callback(CURL *parent,
164 CURL *easy,
165 size_t num_headers,
166 struct curl_pushheaders *headers,
167 void *userp)
168 {
169 char *headp;
170 size_t i;
171 int *transfers = (int *)userp;
172 char filename[128];
173 FILE *out;
174 static unsigned int count = 0;
175
176 (void)parent; /* we have no use for this */
177
178 snprintf(filename, 128, "push%u", count++);
179
180 /* here's a new stream, save it in a new file for each new push */
181 out = fopen(filename, "wb");
182 if(!out) {
183 /* if we can't save it, deny it */
184 fprintf(stderr, "Failed to create output file for push\n");
185 return CURL_PUSH_DENY;
186 }
187
188 /* write to this file */
189 curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);
190
191 fprintf(stderr, "**** push callback approves stream %u, got %lu headers!\n",
192 count, (unsigned long)num_headers);
193
194 for(i = 0; i<num_headers; i++) {
195 headp = curl_pushheader_bynum(headers, i);
196 fprintf(stderr, "**** header %lu: %s\n", (unsigned long)i, headp);
197 }
198
199 headp = curl_pushheader_byname(headers, ":path");
200 if(headp) {
201 fprintf(stderr, "**** The PATH is %s\n", headp /* skip :path + colon */);
202 }
203
204 (*transfers)++; /* one more */
205 return CURL_PUSH_OK;
206 }
207
208
209 /*
210 * Download a file over HTTP/2, take care of server push.
211 */
main(void)212 int main(void)
213 {
214 CURL *easy;
215 CURLM *multi_handle;
216 int transfers = 1; /* we start with one */
217 struct CURLMsg *m;
218
219 /* init a multi stack */
220 multi_handle = curl_multi_init();
221
222 easy = curl_easy_init();
223
224 /* set options */
225 if(setup(easy)) {
226 fprintf(stderr, "failed\n");
227 return 1;
228 }
229
230 /* add the easy transfer */
231 curl_multi_add_handle(multi_handle, easy);
232
233 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
234 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback);
235 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers);
236
237 do {
238 int still_running; /* keep number of running handles */
239 CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
240
241 if(still_running)
242 /* wait for activity, timeout or "nothing" */
243 mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
244
245 if(mc)
246 break;
247
248 /*
249 * A little caution when doing server push is that libcurl itself has
250 * created and added one or more easy handles but we need to clean them up
251 * when we are done.
252 */
253
254 do {
255 int msgq = 0;
256 m = curl_multi_info_read(multi_handle, &msgq);
257 if(m && (m->msg == CURLMSG_DONE)) {
258 CURL *e = m->easy_handle;
259 transfers--;
260 curl_multi_remove_handle(multi_handle, e);
261 curl_easy_cleanup(e);
262 }
263 } while(m);
264
265 } while(transfers); /* as long as we have transfers going */
266
267 curl_multi_cleanup(multi_handle);
268
269
270 return 0;
271 }
272