http2-serverpush.c (7363B)
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 #include <curl/mprintf.h> 35 36 #ifndef CURLPIPE_MULTIPLEX 37 #error "too old libcurl, cannot do HTTP/2 server push!" 38 #endif 39 40 static 41 void dump(const char *text, unsigned char *ptr, size_t size, 42 char nohex) 43 { 44 size_t i; 45 size_t c; 46 47 unsigned int width = 0x10; 48 49 if(nohex) 50 /* without the hex output, we can fit more on screen */ 51 width = 0x40; 52 53 fprintf(stderr, "%s, %lu bytes (0x%lx)\n", 54 text, (unsigned long)size, (unsigned long)size); 55 56 for(i = 0; i < size; i += width) { 57 58 fprintf(stderr, "%4.4lx: ", (unsigned long)i); 59 60 if(!nohex) { 61 /* hex not disabled, show it */ 62 for(c = 0; c < width; c++) 63 if(i + c < size) 64 fprintf(stderr, "%02x ", ptr[i + c]); 65 else 66 fputs(" ", stderr); 67 } 68 69 for(c = 0; (c < width) && (i + c < size); c++) { 70 /* check for 0D0A; if found, skip past and start a new line of output */ 71 if(nohex && (i + c + 1 < size) && ptr[i + c] == 0x0D && 72 ptr[i + c + 1] == 0x0A) { 73 i += (c + 2 - width); 74 break; 75 } 76 fprintf(stderr, "%c", 77 (ptr[i + c] >= 0x20) && (ptr[i + c] < 0x80) ? ptr[i + c] : '.'); 78 /* check again for 0D0A, to avoid an extra \n if it's at width */ 79 if(nohex && (i + c + 2 < size) && ptr[i + c + 1] == 0x0D && 80 ptr[i + c + 2] == 0x0A) { 81 i += (c + 3 - width); 82 break; 83 } 84 } 85 fputc('\n', stderr); /* newline */ 86 } 87 } 88 89 static 90 int my_trace(CURL *handle, curl_infotype type, 91 char *data, size_t size, 92 void *userp) 93 { 94 const char *text; 95 (void)handle; /* prevent compiler warning */ 96 (void)userp; 97 switch(type) { 98 case CURLINFO_TEXT: 99 fprintf(stderr, "== Info: %s", data); 100 return 0; 101 case CURLINFO_HEADER_OUT: 102 text = "=> Send header"; 103 break; 104 case CURLINFO_DATA_OUT: 105 text = "=> Send data"; 106 break; 107 case CURLINFO_SSL_DATA_OUT: 108 text = "=> Send SSL data"; 109 break; 110 case CURLINFO_HEADER_IN: 111 text = "<= Recv header"; 112 break; 113 case CURLINFO_DATA_IN: 114 text = "<= Recv data"; 115 break; 116 case CURLINFO_SSL_DATA_IN: 117 text = "<= Recv SSL data"; 118 break; 119 default: /* in case a new one is introduced to shock us */ 120 return 0; 121 } 122 123 dump(text, (unsigned char *)data, size, 1); 124 return 0; 125 } 126 127 #define OUTPUTFILE "dl" 128 129 static int setup(CURL *hnd, const char *url) 130 { 131 FILE *out = fopen(OUTPUTFILE, "wb"); 132 if(!out) 133 /* failed */ 134 return 1; 135 136 /* write to this file */ 137 curl_easy_setopt(hnd, CURLOPT_WRITEDATA, out); 138 139 /* set the same URL */ 140 curl_easy_setopt(hnd, CURLOPT_URL, url); 141 142 /* please be verbose */ 143 curl_easy_setopt(hnd, CURLOPT_VERBOSE, 1L); 144 curl_easy_setopt(hnd, CURLOPT_DEBUGFUNCTION, my_trace); 145 146 /* HTTP/2 please */ 147 curl_easy_setopt(hnd, CURLOPT_HTTP_VERSION, CURL_HTTP_VERSION_2_0); 148 149 /* we use a self-signed test server, skip verification during debugging */ 150 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYPEER, 0L); 151 curl_easy_setopt(hnd, CURLOPT_SSL_VERIFYHOST, 0L); 152 153 #if (CURLPIPE_MULTIPLEX > 0) 154 /* wait for pipe connection to confirm */ 155 curl_easy_setopt(hnd, CURLOPT_PIPEWAIT, 1L); 156 #endif 157 return 0; /* all is good */ 158 } 159 160 /* called when there is an incoming push */ 161 static int server_push_callback(CURL *parent, 162 CURL *easy, 163 size_t num_headers, 164 struct curl_pushheaders *headers, 165 void *userp) 166 { 167 char *headp; 168 size_t i; 169 int *transfers = (int *)userp; 170 char filename[128]; 171 FILE *out; 172 static unsigned int count = 0; 173 174 (void)parent; /* we have no use for this */ 175 176 curl_msnprintf(filename, 128, "push%u", count++); 177 178 /* here's a new stream, save it in a new file for each new push */ 179 out = fopen(filename, "wb"); 180 if(!out) { 181 /* if we cannot save it, deny it */ 182 fprintf(stderr, "Failed to create output file for push\n"); 183 return CURL_PUSH_DENY; 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 return CURL_PUSH_OK; 204 } 205 206 207 /* 208 * Download a file over HTTP/2, take care of server push. 209 */ 210 int main(int argc, char *argv[]) 211 { 212 CURL *easy; 213 CURLM *multi_handle; 214 int transfers = 1; /* we start with one */ 215 struct CURLMsg *m; 216 const char *url = "https://localhost:8443/index.html"; 217 218 if(argc == 2) 219 url = argv[1]; 220 221 /* init a multi stack */ 222 multi_handle = curl_multi_init(); 223 224 easy = curl_easy_init(); 225 226 /* set options */ 227 if(setup(easy, url)) { 228 fprintf(stderr, "failed\n"); 229 return 1; 230 } 231 232 /* add the easy transfer */ 233 curl_multi_add_handle(multi_handle, easy); 234 235 curl_multi_setopt(multi_handle, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX); 236 curl_multi_setopt(multi_handle, CURLMOPT_PUSHFUNCTION, server_push_callback); 237 curl_multi_setopt(multi_handle, CURLMOPT_PUSHDATA, &transfers); 238 239 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 */ 255 256 do { 257 int msgq = 0; 258 m = curl_multi_info_read(multi_handle, &msgq); 259 if(m && (m->msg == CURLMSG_DONE)) { 260 CURL *e = m->easy_handle; 261 transfers--; 262 curl_multi_remove_handle(multi_handle, e); 263 curl_easy_cleanup(e); 264 } 265 } while(m); 266 267 } while(transfers); /* as long as we have transfers going */ 268 269 curl_multi_cleanup(multi_handle); 270 271 272 return 0; 273 }