1 /* $NetBSD: http-server.c,v 1.1.1.4 2021/04/07 02:43:15 christos Exp $ */ 2 /* 3 A trivial static http webserver using Libevent's evhttp. 4 5 This is not the best code in the world, and it does some fairly stupid stuff 6 that you would never want to do in a production webserver. Caveat hackor! 7 8 */ 9 10 /* Compatibility for possible missing IPv6 declarations */ 11 #include "../util-internal.h" 12 13 #include <stdio.h> 14 #include <stdlib.h> 15 #include <string.h> 16 17 #include <sys/types.h> 18 #include <sys/stat.h> 19 20 #ifdef _WIN32 21 #include <winsock2.h> 22 #include <ws2tcpip.h> 23 #include <windows.h> 24 #include <getopt.h> 25 #include <io.h> 26 #include <fcntl.h> 27 #ifndef S_ISDIR 28 #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR) 29 #endif 30 #else /* !_WIN32 */ 31 #include <sys/stat.h> 32 #include <sys/socket.h> 33 #include <fcntl.h> 34 #include <unistd.h> 35 #include <dirent.h> 36 #endif /* _WIN32 */ 37 #include <signal.h> 38 39 #ifdef EVENT__HAVE_SYS_UN_H 40 #include <sys/un.h> 41 #endif 42 #ifdef EVENT__HAVE_AFUNIX_H 43 #include <afunix.h> 44 #endif 45 46 #include <event2/event.h> 47 #include <event2/http.h> 48 #include <event2/listener.h> 49 #include <event2/buffer.h> 50 #include <event2/util.h> 51 #include <event2/keyvalq_struct.h> 52 53 #ifdef _WIN32 54 #include <event2/thread.h> 55 #endif /* _WIN32 */ 56 57 #ifdef EVENT__HAVE_NETINET_IN_H 58 #include <netinet/in.h> 59 # ifdef _XOPEN_SOURCE_EXTENDED 60 # include <arpa/inet.h> 61 # endif 62 #endif 63 64 #ifdef _WIN32 65 #ifndef stat 66 #define stat _stat 67 #endif 68 #ifndef fstat 69 #define fstat _fstat 70 #endif 71 #ifndef open 72 #define open _open 73 #endif 74 #ifndef close 75 #define close _close 76 #endif 77 #ifndef O_RDONLY 78 #define O_RDONLY _O_RDONLY 79 #endif 80 #endif /* _WIN32 */ 81 82 char uri_root[512]; 83 84 static const struct table_entry { 85 const char *extension; 86 const char *content_type; 87 } content_type_table[] = { 88 { "txt", "text/plain" }, 89 { "c", "text/plain" }, 90 { "h", "text/plain" }, 91 { "html", "text/html" }, 92 { "htm", "text/htm" }, 93 { "css", "text/css" }, 94 { "gif", "image/gif" }, 95 { "jpg", "image/jpeg" }, 96 { "jpeg", "image/jpeg" }, 97 { "png", "image/png" }, 98 { "pdf", "application/pdf" }, 99 { "ps", "application/postscript" }, 100 { NULL, NULL }, 101 }; 102 103 struct options { 104 int port; 105 int iocp; 106 int verbose; 107 108 int unlink; 109 const char *unixsock; 110 const char *docroot; 111 }; 112 113 /* Try to guess a good content-type for 'path' */ 114 static const char * 115 guess_content_type(const char *path) 116 { 117 const char *last_period, *extension; 118 const struct table_entry *ent; 119 last_period = strrchr(path, '.'); 120 if (!last_period || strchr(last_period, '/')) 121 goto not_found; /* no exension */ 122 extension = last_period + 1; 123 for (ent = &content_type_table[0]; ent->extension; ++ent) { 124 if (!evutil_ascii_strcasecmp(ent->extension, extension)) 125 return ent->content_type; 126 } 127 128 not_found: 129 return "application/misc"; 130 } 131 132 /* Callback used for the /dump URI, and for every non-GET request: 133 * dumps all information to stdout and gives back a trivial 200 ok */ 134 static void 135 dump_request_cb(struct evhttp_request *req, void *arg) 136 { 137 const char *cmdtype; 138 struct evkeyvalq *headers; 139 struct evkeyval *header; 140 struct evbuffer *buf; 141 142 switch (evhttp_request_get_command(req)) { 143 case EVHTTP_REQ_GET: cmdtype = "GET"; break; 144 case EVHTTP_REQ_POST: cmdtype = "POST"; break; 145 case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break; 146 case EVHTTP_REQ_PUT: cmdtype = "PUT"; break; 147 case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break; 148 case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break; 149 case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break; 150 case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break; 151 case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break; 152 default: cmdtype = "unknown"; break; 153 } 154 155 printf("Received a %s request for %s\nHeaders:\n", 156 cmdtype, evhttp_request_get_uri(req)); 157 158 headers = evhttp_request_get_input_headers(req); 159 for (header = headers->tqh_first; header; 160 header = header->next.tqe_next) { 161 printf(" %s: %s\n", header->key, header->value); 162 } 163 164 buf = evhttp_request_get_input_buffer(req); 165 puts("Input data: <<<"); 166 while (evbuffer_get_length(buf)) { 167 int n; 168 char cbuf[128]; 169 n = evbuffer_remove(buf, cbuf, sizeof(cbuf)); 170 if (n > 0) 171 (void) fwrite(cbuf, 1, n, stdout); 172 } 173 puts(">>>"); 174 175 evhttp_send_reply(req, 200, "OK", NULL); 176 } 177 178 /* This callback gets invoked when we get any http request that doesn't match 179 * any other callback. Like any evhttp server callback, it has a simple job: 180 * it must eventually call evhttp_send_error() or evhttp_send_reply(). 181 */ 182 static void 183 send_document_cb(struct evhttp_request *req, void *arg) 184 { 185 struct evbuffer *evb = NULL; 186 struct options *o = arg; 187 const char *uri = evhttp_request_get_uri(req); 188 struct evhttp_uri *decoded = NULL; 189 const char *path; 190 char *decoded_path; 191 char *whole_path = NULL; 192 size_t len; 193 int fd = -1; 194 struct stat st; 195 196 if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) { 197 dump_request_cb(req, arg); 198 return; 199 } 200 201 printf("Got a GET request for <%s>\n", uri); 202 203 /* Decode the URI */ 204 decoded = evhttp_uri_parse(uri); 205 if (!decoded) { 206 printf("It's not a good URI. Sending BADREQUEST\n"); 207 evhttp_send_error(req, HTTP_BADREQUEST, 0); 208 return; 209 } 210 211 /* Let's see what path the user asked for. */ 212 path = evhttp_uri_get_path(decoded); 213 if (!path) path = "/"; 214 215 /* We need to decode it, to see what path the user really wanted. */ 216 decoded_path = evhttp_uridecode(path, 0, NULL); 217 if (decoded_path == NULL) 218 goto err; 219 /* Don't allow any ".."s in the path, to avoid exposing stuff outside 220 * of the docroot. This test is both overzealous and underzealous: 221 * it forbids aceptable paths like "/this/one..here", but it doesn't 222 * do anything to prevent symlink following." */ 223 if (strstr(decoded_path, "..")) 224 goto err; 225 226 len = strlen(decoded_path)+strlen(o->docroot)+2; 227 if (!(whole_path = malloc(len))) { 228 perror("malloc"); 229 goto err; 230 } 231 evutil_snprintf(whole_path, len, "%s/%s", o->docroot, decoded_path); 232 233 if (stat(whole_path, &st)<0) { 234 goto err; 235 } 236 237 /* This holds the content we're sending. */ 238 evb = evbuffer_new(); 239 240 if (S_ISDIR(st.st_mode)) { 241 /* If it's a directory, read the comments and make a little 242 * index page */ 243 #ifdef _WIN32 244 HANDLE d; 245 WIN32_FIND_DATAA ent; 246 char *pattern; 247 size_t dirlen; 248 #else 249 DIR *d; 250 struct dirent *ent; 251 #endif 252 const char *trailing_slash = ""; 253 254 if (!strlen(path) || path[strlen(path)-1] != '/') 255 trailing_slash = "/"; 256 257 #ifdef _WIN32 258 dirlen = strlen(whole_path); 259 pattern = malloc(dirlen+3); 260 memcpy(pattern, whole_path, dirlen); 261 pattern[dirlen] = '\\'; 262 pattern[dirlen+1] = '*'; 263 pattern[dirlen+2] = '\0'; 264 d = FindFirstFileA(pattern, &ent); 265 free(pattern); 266 if (d == INVALID_HANDLE_VALUE) 267 goto err; 268 #else 269 if (!(d = opendir(whole_path))) 270 goto err; 271 #endif 272 273 evbuffer_add_printf(evb, 274 "<!DOCTYPE html>\n" 275 "<html>\n <head>\n" 276 " <meta charset='utf-8'>\n" 277 " <title>%s</title>\n" 278 " <base href='%s%s'>\n" 279 " </head>\n" 280 " <body>\n" 281 " <h1>%s</h1>\n" 282 " <ul>\n", 283 decoded_path, /* XXX html-escape this. */ 284 path, /* XXX html-escape this? */ 285 trailing_slash, 286 decoded_path /* XXX html-escape this */); 287 #ifdef _WIN32 288 do { 289 const char *name = ent.cFileName; 290 #else 291 while ((ent = readdir(d))) { 292 const char *name = ent->d_name; 293 #endif 294 evbuffer_add_printf(evb, 295 " <li><a href=\"%s\">%s</a>\n", 296 name, name);/* XXX escape this */ 297 #ifdef _WIN32 298 } while (FindNextFileA(d, &ent)); 299 #else 300 } 301 #endif 302 evbuffer_add_printf(evb, "</ul></body></html>\n"); 303 #ifdef _WIN32 304 FindClose(d); 305 #else 306 closedir(d); 307 #endif 308 evhttp_add_header(evhttp_request_get_output_headers(req), 309 "Content-Type", "text/html"); 310 } else { 311 /* Otherwise it's a file; add it to the buffer to get 312 * sent via sendfile */ 313 const char *type = guess_content_type(decoded_path); 314 if ((fd = open(whole_path, O_RDONLY)) < 0) { 315 perror("open"); 316 goto err; 317 } 318 319 if (fstat(fd, &st)<0) { 320 /* Make sure the length still matches, now that we 321 * opened the file :/ */ 322 perror("fstat"); 323 goto err; 324 } 325 evhttp_add_header(evhttp_request_get_output_headers(req), 326 "Content-Type", type); 327 evbuffer_add_file(evb, fd, 0, st.st_size); 328 } 329 330 evhttp_send_reply(req, 200, "OK", evb); 331 goto done; 332 err: 333 evhttp_send_error(req, 404, "Document was not found"); 334 if (fd>=0) 335 close(fd); 336 done: 337 if (decoded) 338 evhttp_uri_free(decoded); 339 if (decoded_path) 340 free(decoded_path); 341 if (whole_path) 342 free(whole_path); 343 if (evb) 344 evbuffer_free(evb); 345 } 346 347 static void 348 print_usage(FILE *out, const char *prog, int exit_code) 349 { 350 fprintf(out, 351 "Syntax: %s [ OPTS ] <docroot>\n" 352 " -p - port\n" 353 " -U - bind to unix socket\n" 354 " -u - unlink unix socket before bind\n" 355 " -I - IOCP\n" 356 " -v - verbosity, enables libevent debug logging too\n", prog); 357 exit(exit_code); 358 } 359 static struct options 360 parse_opts(int argc, char **argv) 361 { 362 struct options o; 363 int opt; 364 365 memset(&o, 0, sizeof(o)); 366 367 while ((opt = getopt(argc, argv, "hp:U:uIv")) != -1) { 368 switch (opt) { 369 case 'p': o.port = atoi(optarg); break; 370 case 'U': o.unixsock = optarg; break; 371 case 'u': o.unlink = 1; break; 372 case 'I': o.iocp = 1; break; 373 case 'v': ++o.verbose; break; 374 case 'h': print_usage(stdout, argv[0], 0); break; 375 default : fprintf(stderr, "Unknown option %c\n", opt); break; 376 } 377 } 378 379 if (optind >= argc || (argc - optind) > 1) { 380 print_usage(stdout, argv[0], 1); 381 } 382 o.docroot = argv[optind]; 383 384 return o; 385 } 386 387 static void 388 do_term(int sig, short events, void *arg) 389 { 390 struct event_base *base = arg; 391 event_base_loopbreak(base); 392 fprintf(stderr, "Got %i, Terminating\n", sig); 393 } 394 395 static int 396 display_listen_sock(struct evhttp_bound_socket *handle) 397 { 398 struct sockaddr_storage ss; 399 evutil_socket_t fd; 400 ev_socklen_t socklen = sizeof(ss); 401 char addrbuf[128]; 402 void *inaddr; 403 const char *addr; 404 int got_port = -1; 405 406 fd = evhttp_bound_socket_get_fd(handle); 407 memset(&ss, 0, sizeof(ss)); 408 if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) { 409 perror("getsockname() failed"); 410 return 1; 411 } 412 413 if (ss.ss_family == AF_INET) { 414 got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port); 415 inaddr = &((struct sockaddr_in*)&ss)->sin_addr; 416 } else if (ss.ss_family == AF_INET6) { 417 got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port); 418 inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr; 419 } 420 #ifdef EVENT__HAVE_STRUCT_SOCKADDR_UN 421 else if (ss.ss_family == AF_UNIX) { 422 printf("Listening on <%s>\n", ((struct sockaddr_un*)&ss)->sun_path); 423 return 0; 424 } 425 #endif 426 else { 427 fprintf(stderr, "Weird address family %d\n", 428 ss.ss_family); 429 return 1; 430 } 431 432 addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf, 433 sizeof(addrbuf)); 434 if (addr) { 435 printf("Listening on %s:%d\n", addr, got_port); 436 evutil_snprintf(uri_root, sizeof(uri_root), 437 "http://%s:%d",addr,got_port); 438 } else { 439 fprintf(stderr, "evutil_inet_ntop failed\n"); 440 return 1; 441 } 442 443 return 0; 444 } 445 446 int 447 main(int argc, char **argv) 448 { 449 struct event_config *cfg = NULL; 450 struct event_base *base = NULL; 451 struct evhttp *http = NULL; 452 struct evhttp_bound_socket *handle = NULL; 453 struct evconnlistener *lev = NULL; 454 struct event *term = NULL; 455 struct options o = parse_opts(argc, argv); 456 int ret = 0; 457 458 #ifdef _WIN32 459 { 460 WORD wVersionRequested; 461 WSADATA wsaData; 462 wVersionRequested = MAKEWORD(2, 2); 463 WSAStartup(wVersionRequested, &wsaData); 464 } 465 #else 466 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) { 467 ret = 1; 468 goto err; 469 } 470 #endif 471 472 setbuf(stdout, NULL); 473 setbuf(stderr, NULL); 474 475 /** Read env like in regress */ 476 if (o.verbose || getenv("EVENT_DEBUG_LOGGING_ALL")) 477 event_enable_debug_logging(EVENT_DBG_ALL); 478 479 cfg = event_config_new(); 480 #ifdef _WIN32 481 if (o.iocp) { 482 #ifdef EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED 483 evthread_use_windows_threads(); 484 event_config_set_num_cpus_hint(cfg, 8); 485 #endif 486 event_config_set_flag(cfg, EVENT_BASE_FLAG_STARTUP_IOCP); 487 } 488 #endif 489 490 base = event_base_new_with_config(cfg); 491 if (!base) { 492 fprintf(stderr, "Couldn't create an event_base: exiting\n"); 493 ret = 1; 494 } 495 event_config_free(cfg); 496 cfg = NULL; 497 498 /* Create a new evhttp object to handle requests. */ 499 http = evhttp_new(base); 500 if (!http) { 501 fprintf(stderr, "couldn't create evhttp. Exiting.\n"); 502 ret = 1; 503 } 504 505 /* The /dump URI will dump all requests to stdout and say 200 ok. */ 506 evhttp_set_cb(http, "/dump", dump_request_cb, NULL); 507 508 /* We want to accept arbitrary requests, so we need to set a "generic" 509 * cb. We can also add callbacks for specific paths. */ 510 evhttp_set_gencb(http, send_document_cb, &o); 511 512 if (o.unixsock) { 513 #ifdef EVENT__HAVE_STRUCT_SOCKADDR_UN 514 struct sockaddr_un addr; 515 516 if (o.unlink && (unlink(o.unixsock) && errno != ENOENT)) { 517 perror(o.unixsock); 518 ret = 1; 519 goto err; 520 } 521 522 addr.sun_family = AF_UNIX; 523 strcpy(addr.sun_path, o.unixsock); 524 525 lev = evconnlistener_new_bind(base, NULL, NULL, 526 LEV_OPT_CLOSE_ON_FREE, -1, 527 (struct sockaddr *)&addr, sizeof(addr)); 528 if (!lev) { 529 perror("Cannot create listener"); 530 ret = 1; 531 goto err; 532 } 533 534 handle = evhttp_bind_listener(http, lev); 535 if (!handle) { 536 fprintf(stderr, "couldn't bind to %s. Exiting.\n", o.unixsock); 537 ret = 1; 538 goto err; 539 } 540 #else /* !EVENT__HAVE_STRUCT_SOCKADDR_UN */ 541 fprintf(stderr, "-U is not supported on this platform. Exiting.\n"); 542 ret = 1; 543 goto err; 544 #endif /* EVENT__HAVE_STRUCT_SOCKADDR_UN */ 545 } 546 else { 547 handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", o.port); 548 if (!handle) { 549 fprintf(stderr, "couldn't bind to port %d. Exiting.\n", o.port); 550 ret = 1; 551 goto err; 552 } 553 } 554 555 if (display_listen_sock(handle)) { 556 ret = 1; 557 goto err; 558 } 559 560 term = evsignal_new(base, SIGINT, do_term, base); 561 if (!term) 562 goto err; 563 if (event_add(term, NULL)) 564 goto err; 565 566 event_base_dispatch(base); 567 568 #ifdef _WIN32 569 WSACleanup(); 570 #endif 571 572 err: 573 if (cfg) 574 event_config_free(cfg); 575 if (http) 576 evhttp_free(http); 577 if (term) 578 event_free(term); 579 if (base) 580 event_base_free(base); 581 582 return ret; 583 } 584