Annotation of embedaddon/curl/docs/examples/http2-serverpush.c, revision 1.1.1.1
1.1 misho 1: /***************************************************************************
2: * _ _ ____ _
3: * Project ___| | | | _ \| |
4: * / __| | | | |_) | |
5: * | (__| |_| | _ <| |___
6: * \___|\___/|_| \_\_____|
7: *
8: * Copyright (C) 1998 - 2019, 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.haxx.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
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
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:
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 */
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: */
212: int main(void)
213: {
214: CURL *easy;
215: CURLM *multi_handle;
216: int still_running; /* keep number of running handles */
217: int transfers = 1; /* we start with one */
218: struct CURLMsg *m;
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)) {
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: /* we start some action by calling perform right away */
239: curl_multi_perform(multi_handle, &still_running);
240:
241: do {
242: struct timeval timeout;
243: int rc; /* select() return code */
244: CURLMcode mc; /* curl_multi_fdset() return code */
245:
246: fd_set fdread;
247: fd_set fdwrite;
248: fd_set fdexcep;
249: int maxfd = -1;
250:
251: long curl_timeo = -1;
252:
253: FD_ZERO(&fdread);
254: FD_ZERO(&fdwrite);
255: FD_ZERO(&fdexcep);
256:
257: /* set a suitable timeout to play around with */
258: timeout.tv_sec = 1;
259: timeout.tv_usec = 0;
260:
261: curl_multi_timeout(multi_handle, &curl_timeo);
262: if(curl_timeo >= 0) {
263: timeout.tv_sec = curl_timeo / 1000;
264: if(timeout.tv_sec > 1)
265: timeout.tv_sec = 1;
266: else
267: timeout.tv_usec = (curl_timeo % 1000) * 1000;
268: }
269:
270: /* get file descriptors from the transfers */
271: mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
272:
273: if(mc != CURLM_OK) {
274: fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
275: break;
276: }
277:
278: /* On success the value of maxfd is guaranteed to be >= -1. We call
279: select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
280: no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
281: to sleep 100ms, which is the minimum suggested value in the
282: curl_multi_fdset() doc. */
283:
284: if(maxfd == -1) {
285: #ifdef _WIN32
286: Sleep(100);
287: rc = 0;
288: #else
289: /* Portable sleep for platforms other than Windows. */
290: struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
291: rc = select(0, NULL, NULL, NULL, &wait);
292: #endif
293: }
294: else {
295: /* Note that on some platforms 'timeout' may be modified by select().
296: If you need access to the original value save a copy beforehand. */
297: rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
298: }
299:
300: switch(rc) {
301: case -1:
302: /* select error */
303: break;
304: case 0:
305: default:
306: /* timeout or readable/writable sockets */
307: curl_multi_perform(multi_handle, &still_running);
308: break;
309: }
310:
311: /*
312: * A little caution when doing server push is that libcurl itself has
313: * created and added one or more easy handles but we need to clean them up
314: * when we are done.
315: */
316:
317: do {
318: int msgq = 0;;
319: m = curl_multi_info_read(multi_handle, &msgq);
320: if(m && (m->msg == CURLMSG_DONE)) {
321: CURL *e = m->easy_handle;
322: transfers--;
323: curl_multi_remove_handle(multi_handle, e);
324: curl_easy_cleanup(e);
325: }
326: } while(m);
327:
328: } while(transfers); /* as long as we have transfers going */
329:
330: curl_multi_cleanup(multi_handle);
331:
332:
333: return 0;
334: }
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