Andy Green | ff95d7a | 2010-10-28 22:36:01 +0100 | [diff] [blame^] | 1 | #include <stdio.h> |
| 2 | #include <stdlib.h> |
| 3 | #include <string.h> |
| 4 | #include <ctype.h> |
| 5 | #include <unistd.h> |
| 6 | |
| 7 | #include <sys/types.h> |
| 8 | #include <sys/socket.h> |
| 9 | #include <netinet/in.h> |
| 10 | |
| 11 | #include <poll.h> |
| 12 | #include <sys/mman.h> |
| 13 | |
| 14 | #include "libwebsockets.h" |
| 15 | |
| 16 | void md5(const unsigned char *input, int ilen, unsigned char output[16]); |
| 17 | |
| 18 | void dostuff(struct libwebsocket *wsi, int sock); |
| 19 | |
| 20 | const struct lws_tokens lws_tokens[WSI_TOKEN_COUNT] = { |
| 21 | { "GET ", 4 }, |
| 22 | { "Host:", 5 }, |
| 23 | { "Connection:", 11 }, |
| 24 | { "Sec-WebSocket-Key1:", 19 }, |
| 25 | { "Sec-WebSocket-Key2:", 19 }, |
| 26 | { "Sec-WebSocket-Protocol:", 23 }, |
| 27 | { "Upgrade:", 8 }, |
| 28 | { "Origin:", 7 }, |
| 29 | { "\x0d\x0a", 2 }, |
| 30 | }; |
| 31 | |
| 32 | int libwebsocket_init(struct libwebsocket *wsi, int port) |
| 33 | { |
| 34 | int n; |
| 35 | int sockfd, newsockfd; |
| 36 | unsigned int clilen; |
| 37 | struct sockaddr_in serv_addr, cli_addr; |
| 38 | int pid; |
| 39 | |
| 40 | wsi->state = WSI_STATE_CLOSED; |
| 41 | wsi->name_buffer_pos = 0; |
| 42 | wsi->response = NULL; |
| 43 | |
| 44 | for (n = 0; n < WSI_TOKEN_COUNT; n++) { |
| 45 | wsi->utf8_token[n].token = NULL; |
| 46 | wsi->utf8_token[n].token_len = 0; |
| 47 | } |
| 48 | |
| 49 | /* fork off a master server for this websocket server */ |
| 50 | |
| 51 | n = fork(); |
| 52 | if (n < 0) { |
| 53 | fprintf(stderr, "Failed on forking server thread: %d\n", n); |
| 54 | exit(1); |
| 55 | } |
| 56 | |
| 57 | /* we are done as far as the caller is concerned */ |
| 58 | |
| 59 | if (n) |
| 60 | return 0; |
| 61 | |
| 62 | /* sit there listening for connects, accept and spawn session servers */ |
| 63 | |
| 64 | sockfd = socket(AF_INET, SOCK_STREAM, 0); |
| 65 | if (sockfd < 0) |
| 66 | fprintf(stderr, "ERROR opening socket"); |
| 67 | bzero((char *) &serv_addr, sizeof(serv_addr)); |
| 68 | |
| 69 | serv_addr.sin_family = AF_INET; |
| 70 | serv_addr.sin_addr.s_addr = INADDR_ANY; |
| 71 | serv_addr.sin_port = htons(port); |
| 72 | if (bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0) |
| 73 | fprintf(stderr, "ERROR on binding"); |
| 74 | |
| 75 | listen(sockfd, 5); |
| 76 | |
| 77 | while (1) { |
| 78 | clilen = sizeof(cli_addr); |
| 79 | |
| 80 | newsockfd = accept(sockfd, (struct sockaddr *) &cli_addr, &clilen); |
| 81 | if (newsockfd < 0) |
| 82 | fprintf(stderr, "ERROR on accept"); |
| 83 | |
| 84 | /* fork off a new server instance */ |
| 85 | |
| 86 | pid = fork(); |
| 87 | if (pid < 0) |
| 88 | fprintf(stderr, "ERROR on fork"); |
| 89 | if (!pid) { |
| 90 | close(sockfd); |
| 91 | |
| 92 | /* sit in dostuff() until session socket closed */ |
| 93 | |
| 94 | dostuff(wsi, newsockfd); |
| 95 | exit(0); |
| 96 | } else |
| 97 | close(newsockfd); |
| 98 | } |
| 99 | } |
| 100 | |
| 101 | void libwebsocket_close(struct libwebsocket *wsi) |
| 102 | { |
| 103 | int n; |
| 104 | |
| 105 | wsi->state = WSI_STATE_DEAD_SOCKET; |
| 106 | |
| 107 | if (wsi->websocket_closed_callback) |
| 108 | wsi->websocket_closed_callback(wsi); |
| 109 | |
| 110 | for (n = 0; n < WSI_TOKEN_COUNT; n++) |
| 111 | if (wsi->utf8_token[n].token) |
| 112 | free(wsi->utf8_token[n].token); |
| 113 | |
| 114 | if (wsi->response) |
| 115 | free(wsi->response); |
| 116 | } |
| 117 | |
| 118 | |
| 119 | static int libwebsocket_parse(struct libwebsocket *wsi, unsigned char c) |
| 120 | { |
| 121 | int n; |
| 122 | |
| 123 | switch (wsi->parser_state) { |
| 124 | case WSI_TOKEN_GET_URI: |
| 125 | case WSI_TOKEN_HOST: |
| 126 | case WSI_TOKEN_CONNECTION: |
| 127 | case WSI_TOKEN_KEY1: |
| 128 | case WSI_TOKEN_KEY2: |
| 129 | case WSI_TOKEN_PROTOCOL: |
| 130 | case WSI_TOKEN_UPGRADE: |
| 131 | case WSI_TOKEN_ORIGIN: |
| 132 | case WSI_TOKEN_CHALLENGE: |
| 133 | |
| 134 | // fprintf(stderr, "WSI_TOKEN_(body %d) '%c'\n", wsi->parser_state, c); |
| 135 | |
| 136 | /* collect into malloc'd buffers */ |
| 137 | /* optional space swallow */ |
| 138 | if (!wsi->utf8_token[wsi->parser_state].token_len && c == ' ') |
| 139 | break; |
| 140 | |
| 141 | /* special case space terminator for get-uri */ |
| 142 | if (wsi->parser_state == WSI_TOKEN_GET_URI && c == ' ') { |
| 143 | wsi->utf8_token[wsi->parser_state].token[ |
| 144 | wsi->utf8_token[wsi->parser_state].token_len] = '\0'; |
| 145 | wsi->parser_state = WSI_TOKEN_SKIPPING; |
| 146 | break; |
| 147 | } |
| 148 | |
| 149 | /* allocate appropriate memory */ |
| 150 | if (wsi->utf8_token[wsi->parser_state].token_len == wsi->current_alloc_len - 1) { |
| 151 | /* need to extend */ |
| 152 | wsi->current_alloc_len += LWS_ADDITIONAL_HDR_ALLOC; |
| 153 | if (wsi->current_alloc_len >= LWS_MAX_HEADER_LEN) { |
| 154 | /* it's waaay to much payload, fail it */ |
| 155 | strcpy(wsi->utf8_token[wsi->parser_state].token, |
| 156 | "!!! Length exceeded maximum supported !!!"); |
| 157 | wsi->parser_state = WSI_TOKEN_SKIPPING; |
| 158 | break; |
| 159 | } |
| 160 | wsi->utf8_token[wsi->parser_state].token = |
| 161 | realloc(wsi->utf8_token[wsi->parser_state].token, |
| 162 | wsi->current_alloc_len); |
| 163 | } |
| 164 | |
| 165 | /* bail at EOL */ |
| 166 | if (wsi->parser_state != WSI_TOKEN_CHALLENGE && c == '\x0d') { |
| 167 | wsi->utf8_token[wsi->parser_state].token[ |
| 168 | wsi->utf8_token[wsi->parser_state].token_len] = '\0'; |
| 169 | wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; |
| 170 | break; |
| 171 | } |
| 172 | |
| 173 | wsi->utf8_token[wsi->parser_state].token[ |
| 174 | wsi->utf8_token[wsi->parser_state].token_len++] = c; |
| 175 | |
| 176 | /* special payload limiting */ |
| 177 | if (wsi->parser_state == WSI_TOKEN_CHALLENGE) |
| 178 | if (wsi->utf8_token[wsi->parser_state].token_len == 8) { |
| 179 | // fprintf(stderr, "Setting WSI_PARSING_COMPLETE\n"); |
| 180 | wsi->parser_state = WSI_PARSING_COMPLETE; |
| 181 | break; |
| 182 | } |
| 183 | |
| 184 | break; |
| 185 | |
| 186 | /* collecting and checking a name part */ |
| 187 | case WSI_TOKEN_NAME_PART: |
| 188 | // fprintf(stderr, "WSI_TOKEN_NAME_PART '%c'\n", c); |
| 189 | |
| 190 | if (wsi->name_buffer_pos == sizeof(wsi->name_buffer) - 1) { |
| 191 | /* name bigger than we can handle, skip until next */ |
| 192 | wsi->parser_state = WSI_TOKEN_SKIPPING; |
| 193 | break; |
| 194 | } |
| 195 | wsi->name_buffer[wsi->name_buffer_pos++] = c; |
| 196 | wsi->name_buffer[wsi->name_buffer_pos] = '\0'; |
| 197 | |
| 198 | for (n = 0; n < WSI_TOKEN_COUNT; n++) { |
| 199 | if (wsi->name_buffer_pos != lws_tokens[n].token_len) |
| 200 | continue; |
| 201 | if (strcmp(lws_tokens[n].token, wsi->name_buffer)) |
| 202 | continue; |
| 203 | wsi->parser_state = WSI_TOKEN_GET_URI + n; |
| 204 | wsi->current_alloc_len = LWS_INITIAL_HDR_ALLOC; |
| 205 | wsi->utf8_token[wsi->parser_state].token = |
| 206 | malloc(wsi->current_alloc_len); |
| 207 | wsi->utf8_token[wsi->parser_state].token_len = 0; |
| 208 | n = WSI_TOKEN_COUNT; |
| 209 | } |
| 210 | if (wsi->parser_state != WSI_TOKEN_NAME_PART) |
| 211 | break; |
| 212 | break; |
| 213 | |
| 214 | /* skipping arg part of a name we didn't recognize */ |
| 215 | case WSI_TOKEN_SKIPPING: |
| 216 | // fprintf(stderr, "WSI_TOKEN_SKIPPING '%c'\n", c); |
| 217 | if (c == '\x0d') |
| 218 | wsi->parser_state = WSI_TOKEN_SKIPPING_SAW_CR; |
| 219 | break; |
| 220 | case WSI_TOKEN_SKIPPING_SAW_CR: |
| 221 | // fprintf(stderr, "WSI_TOKEN_SKIPPING_SAW_CR '%c'\n", c); |
| 222 | if (c == '\x0a') |
| 223 | wsi->parser_state = WSI_TOKEN_NAME_PART; |
| 224 | else |
| 225 | wsi->parser_state = WSI_TOKEN_SKIPPING; |
| 226 | wsi->name_buffer_pos = 0; |
| 227 | break; |
| 228 | /* we're done, ignore anything else */ |
| 229 | case WSI_PARSING_COMPLETE: |
| 230 | // fprintf(stderr, "WSI_PARSING_COMPLETE '%c'\n", c); |
| 231 | break; |
| 232 | |
| 233 | default: /* keep gcc happy */ |
| 234 | break; |
| 235 | } |
| 236 | |
| 237 | return 0; |
| 238 | } |
| 239 | |
| 240 | static int interpret_key(const char *key, unsigned int *result) |
| 241 | { |
| 242 | char digits[20]; |
| 243 | int digit_pos = 0; |
| 244 | const char *p = key; |
| 245 | int spaces = 0; |
| 246 | |
| 247 | while (*p) { |
| 248 | if (isdigit(*p)) { |
| 249 | if (digit_pos == sizeof(digits) - 1) |
| 250 | return -1; |
| 251 | digits[digit_pos++] = *p; |
| 252 | } |
| 253 | p++; |
| 254 | } |
| 255 | digits[digit_pos] = '\0'; |
| 256 | if (!digit_pos) |
| 257 | return -2; |
| 258 | |
| 259 | while (*key) { |
| 260 | if (*key == ' ') |
| 261 | spaces++; |
| 262 | key++; |
| 263 | } |
| 264 | |
| 265 | if (!spaces) |
| 266 | return -3; |
| 267 | |
| 268 | *result = atol(digits) / spaces; |
| 269 | |
| 270 | return 0; |
| 271 | } |
| 272 | |
| 273 | |
| 274 | /* |
| 275 | * We have to take care about parsing because the headers may be split |
| 276 | * into multiple fragments. They may contain unknown headers with arbitrary |
| 277 | * argument lengths. |
| 278 | */ |
| 279 | |
| 280 | int libwebsocket_read(struct libwebsocket *wsi, unsigned char * buf, size_t len) |
| 281 | { |
| 282 | size_t n; |
| 283 | char *p; |
| 284 | unsigned int key1, key2; |
| 285 | unsigned char sum[16]; |
| 286 | |
| 287 | switch (wsi->state) { |
| 288 | case WSI_STATE_CLOSED: |
| 289 | wsi->state = WSI_STATE_HANDSHAKE_RX; |
| 290 | wsi->parser_state = WSI_TOKEN_NAME_PART; |
| 291 | case WSI_STATE_HANDSHAKE_RX: |
| 292 | |
| 293 | fprintf(stderr, "issuing %ld bytes to parser\n", len); |
| 294 | |
| 295 | |
| 296 | fwrite(buf, 1, len, stderr); |
| 297 | for (n = 0; n< len; n++) |
| 298 | libwebsocket_parse(wsi, *buf++); |
| 299 | |
| 300 | if (wsi->parser_state != WSI_PARSING_COMPLETE) |
| 301 | break; |
| 302 | |
| 303 | fprintf(stderr, "Preparing return packet\n"); |
| 304 | |
| 305 | |
| 306 | /* Confirm we have all the necessary pieces */ |
| 307 | |
| 308 | if ( |
| 309 | !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len || |
| 310 | !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len || |
| 311 | !wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len || |
| 312 | !wsi->utf8_token[WSI_TOKEN_HOST].token_len || |
| 313 | !wsi->utf8_token[WSI_TOKEN_CHALLENGE].token_len || |
| 314 | !wsi->utf8_token[WSI_TOKEN_KEY1].token_len || |
| 315 | !wsi->utf8_token[WSI_TOKEN_KEY2].token_len) { |
| 316 | |
| 317 | /* completed header processing, but missing some bits */ |
| 318 | goto bail; |
| 319 | } |
| 320 | |
| 321 | /* create the response packet */ |
| 322 | |
| 323 | wsi->response = malloc(256 + |
| 324 | wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len + |
| 325 | wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len + |
| 326 | wsi->utf8_token[WSI_TOKEN_HOST].token_len + |
| 327 | wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len + |
| 328 | wsi->utf8_token[WSI_TOKEN_GET_URI].token_len + |
| 329 | wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len); |
| 330 | |
| 331 | |
| 332 | fprintf(stderr, "'%s;\n", wsi->utf8_token[WSI_TOKEN_HOST].token); |
| 333 | |
| 334 | p = wsi->response; |
| 335 | strcpy(p, "HTTP/1.1 101 WebSocket Protocol Handshake\x0d\x0aUpgrade: WebSocket\x0d\x0a"); |
| 336 | p += strlen("HTTP/1.1 101 WebSocket Protocol Handshake\x0d\x0aUpgrade: WebSocket\x0d\x0a"); |
| 337 | strcpy(p, "Connection: Upgrade\x0d\x0aSec-WebSocket-Origin: "); |
| 338 | p += strlen("Connection: Upgrade\x0d\x0aSec-WebSocket-Origin: "); |
| 339 | strcpy(p, wsi->utf8_token[WSI_TOKEN_ORIGIN].token); |
| 340 | p += wsi->utf8_token[WSI_TOKEN_ORIGIN].token_len; |
| 341 | strcpy(p, "\x0d\x0aSec-WebSocket-Location: ws://"); |
| 342 | p += strlen("\x0d\x0aSec-WebSocket-Location: ws://"); |
| 343 | strcpy(p, wsi->utf8_token[WSI_TOKEN_HOST].token); |
| 344 | p += wsi->utf8_token[WSI_TOKEN_HOST].token_len; |
| 345 | strcpy(p, wsi->utf8_token[WSI_TOKEN_GET_URI].token); |
| 346 | p += wsi->utf8_token[WSI_TOKEN_GET_URI].token_len; |
| 347 | strcpy(p, "\x0d\x0aSec-WebSocket-Protocol: "); |
| 348 | p += strlen("\x0d\x0aSec-WebSocket-Protocol: "); |
| 349 | if (wsi->utf8_token[WSI_TOKEN_PROTOCOL].token) { |
| 350 | strcpy(p, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token); |
| 351 | p += wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len; |
| 352 | } |
| 353 | strcpy(p, "\x0d\x0a\x0d\x0a"); |
| 354 | p += strlen("\x0d\x0a\x0d\x0a"); |
| 355 | |
| 356 | if (interpret_key(wsi->utf8_token[WSI_TOKEN_KEY1].token, &key1)) |
| 357 | goto bail; |
| 358 | |
| 359 | if (interpret_key(wsi->utf8_token[WSI_TOKEN_KEY2].token, &key2)) |
| 360 | goto bail; |
| 361 | |
| 362 | sum[0] = key1 >> 24; |
| 363 | sum[1] = key1 >> 16; |
| 364 | sum[2] = key1 >> 8; |
| 365 | sum[3] = key1; |
| 366 | sum[4] = key2 >> 24; |
| 367 | sum[5] = key2 >> 16; |
| 368 | sum[6] = key2 >> 8; |
| 369 | sum[7] = key2; |
| 370 | memcpy(&sum[8], wsi->utf8_token[WSI_TOKEN_CHALLENGE].token, 8); |
| 371 | |
| 372 | md5(sum, 16, (unsigned char *)p); |
| 373 | p += 16; |
| 374 | |
| 375 | wsi->response_length = p - wsi->response; |
| 376 | |
| 377 | wsi->state = WSI_STATE_ISSUE_HANDSHAKE; |
| 378 | |
| 379 | if (wsi->websocket_established_callback) |
| 380 | wsi->websocket_established_callback(wsi); |
| 381 | break; |
| 382 | |
| 383 | case WSI_STATE_ESTABLISHED: |
| 384 | break; |
| 385 | default: |
| 386 | break; |
| 387 | } |
| 388 | |
| 389 | return 0; |
| 390 | |
| 391 | bail: |
| 392 | libwebsocket_close(wsi); |
| 393 | return -1; |
| 394 | } |
| 395 | |
| 396 | |
| 397 | void dostuff(struct libwebsocket *wsi, int sock) |
| 398 | { |
| 399 | int n; |
| 400 | unsigned char buf[256]; |
| 401 | struct pollfd fds; |
| 402 | |
| 403 | wsi->sock = sock; |
| 404 | |
| 405 | fds.fd = sock; |
| 406 | fds.events = POLLIN | POLLOUT; |
| 407 | |
| 408 | while (1) { |
| 409 | |
| 410 | n = poll(&fds, 1, 10); |
| 411 | if (n < 0) { |
| 412 | fprintf(stderr, "Socket dead (poll = %d)\n", n); |
| 413 | return; |
| 414 | } |
| 415 | |
| 416 | if (fds.revents & (POLLERR | POLLHUP)) { |
| 417 | fprintf(stderr, "Socket dead\n"); |
| 418 | return; |
| 419 | } |
| 420 | |
| 421 | if (wsi->state == WSI_STATE_DEAD_SOCKET) |
| 422 | return; |
| 423 | |
| 424 | |
| 425 | if (fds.revents & POLLIN) { |
| 426 | |
| 427 | // fprintf(stderr, "POLLIN\n"); |
| 428 | |
| 429 | n = read(sock, buf, sizeof(buf)); |
| 430 | if (n < 0) { |
| 431 | fprintf(stderr, "Socket read returned %d\n", n); |
| 432 | continue; |
| 433 | } |
| 434 | if (n) |
| 435 | libwebsocket_read(wsi, buf, n); |
| 436 | } |
| 437 | |
| 438 | if (wsi->state == WSI_STATE_ISSUE_HANDSHAKE) { |
| 439 | |
| 440 | fprintf(stderr, "issuing response packet %d len\n", wsi->response_length); |
| 441 | |
| 442 | fwrite(wsi->response, 1, wsi->response_length, stderr); |
| 443 | |
| 444 | n = write(sock, wsi->response, wsi->response_length); |
| 445 | if (n < 0) { |
| 446 | fprintf(stderr, "ERROR writing to socket"); |
| 447 | exit(1); |
| 448 | } |
| 449 | wsi->state = WSI_STATE_ESTABLISHED; |
| 450 | continue; |
| 451 | } |
| 452 | |
| 453 | if (wsi->websocket_send_callback) |
| 454 | wsi->websocket_send_callback(wsi); |
| 455 | } |
| 456 | } |
| 457 | |