1 /* $NetBSD: http-server.c,v 1.1.1.1 2013/04/11 16:43:31 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 #include <stdio.h> 11 #include <stdlib.h> 12 #include <string.h> 13 14 #include <sys/types.h> 15 #include <sys/stat.h> 16 17 #ifdef WIN32 18 #include <winsock2.h> 19 #include <ws2tcpip.h> 20 #include <windows.h> 21 #include <io.h> 22 #include <fcntl.h> 23 #ifndef S_ISDIR 24 #define S_ISDIR(x) (((x) & S_IFMT) == S_IFDIR) 25 #endif 26 #else 27 #include <sys/stat.h> 28 #include <sys/socket.h> 29 #include <signal.h> 30 #include <fcntl.h> 31 #include <unistd.h> 32 #include <dirent.h> 33 #endif 34 35 #include <event2/event.h> 36 #include <event2/http.h> 37 #include <event2/buffer.h> 38 #include <event2/util.h> 39 #include <event2/keyvalq_struct.h> 40 41 #ifdef _EVENT_HAVE_NETINET_IN_H 42 #include <netinet/in.h> 43 # ifdef _XOPEN_SOURCE_EXTENDED 44 # include <arpa/inet.h> 45 # endif 46 #endif 47 48 /* Compatibility for possible missing IPv6 declarations */ 49 #include "../util-internal.h" 50 51 #ifdef WIN32 52 #define stat _stat 53 #define fstat _fstat 54 #define open _open 55 #define close _close 56 #define O_RDONLY _O_RDONLY 57 #endif 58 59 char uri_root[512]; 60 61 static const struct table_entry { 62 const char *extension; 63 const char *content_type; 64 } content_type_table[] = { 65 { "txt", "text/plain" }, 66 { "c", "text/plain" }, 67 { "h", "text/plain" }, 68 { "html", "text/html" }, 69 { "htm", "text/htm" }, 70 { "css", "text/css" }, 71 { "gif", "image/gif" }, 72 { "jpg", "image/jpeg" }, 73 { "jpeg", "image/jpeg" }, 74 { "png", "image/png" }, 75 { "pdf", "application/pdf" }, 76 { "ps", "application/postsript" }, 77 { NULL, NULL }, 78 }; 79 80 /* Try to guess a good content-type for 'path' */ 81 static const char * 82 guess_content_type(const char *path) 83 { 84 const char *last_period, *extension; 85 const struct table_entry *ent; 86 last_period = strrchr(path, '.'); 87 if (!last_period || strchr(last_period, '/')) 88 goto not_found; /* no exension */ 89 extension = last_period + 1; 90 for (ent = &content_type_table[0]; ent->extension; ++ent) { 91 if (!evutil_ascii_strcasecmp(ent->extension, extension)) 92 return ent->content_type; 93 } 94 95 not_found: 96 return "application/misc"; 97 } 98 99 /* Callback used for the /dump URI, and for every non-GET request: 100 * dumps all information to stdout and gives back a trivial 200 ok */ 101 static void 102 dump_request_cb(struct evhttp_request *req, void *arg) 103 { 104 const char *cmdtype; 105 struct evkeyvalq *headers; 106 struct evkeyval *header; 107 struct evbuffer *buf; 108 109 switch (evhttp_request_get_command(req)) { 110 case EVHTTP_REQ_GET: cmdtype = "GET"; break; 111 case EVHTTP_REQ_POST: cmdtype = "POST"; break; 112 case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break; 113 case EVHTTP_REQ_PUT: cmdtype = "PUT"; break; 114 case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break; 115 case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break; 116 case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break; 117 case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break; 118 case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break; 119 default: cmdtype = "unknown"; break; 120 } 121 122 printf("Received a %s request for %s\nHeaders:\n", 123 cmdtype, evhttp_request_get_uri(req)); 124 125 headers = evhttp_request_get_input_headers(req); 126 for (header = headers->tqh_first; header; 127 header = header->next.tqe_next) { 128 printf(" %s: %s\n", header->key, header->value); 129 } 130 131 buf = evhttp_request_get_input_buffer(req); 132 puts("Input data: <<<"); 133 while (evbuffer_get_length(buf)) { 134 int n; 135 char cbuf[128]; 136 n = evbuffer_remove(buf, cbuf, sizeof(buf)-1); 137 if (n > 0) 138 (void) fwrite(cbuf, 1, n, stdout); 139 } 140 puts(">>>"); 141 142 evhttp_send_reply(req, 200, "OK", NULL); 143 } 144 145 /* This callback gets invoked when we get any http request that doesn't match 146 * any other callback. Like any evhttp server callback, it has a simple job: 147 * it must eventually call evhttp_send_error() or evhttp_send_reply(). 148 */ 149 static void 150 send_document_cb(struct evhttp_request *req, void *arg) 151 { 152 struct evbuffer *evb = NULL; 153 const char *docroot = arg; 154 const char *uri = evhttp_request_get_uri(req); 155 struct evhttp_uri *decoded = NULL; 156 const char *path; 157 char *decoded_path; 158 char *whole_path = NULL; 159 size_t len; 160 int fd = -1; 161 struct stat st; 162 163 if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) { 164 dump_request_cb(req, arg); 165 return; 166 } 167 168 printf("Got a GET request for <%s>\n", uri); 169 170 /* Decode the URI */ 171 decoded = evhttp_uri_parse(uri); 172 if (!decoded) { 173 printf("It's not a good URI. Sending BADREQUEST\n"); 174 evhttp_send_error(req, HTTP_BADREQUEST, 0); 175 return; 176 } 177 178 /* Let's see what path the user asked for. */ 179 path = evhttp_uri_get_path(decoded); 180 if (!path) path = "/"; 181 182 /* We need to decode it, to see what path the user really wanted. */ 183 decoded_path = evhttp_uridecode(path, 0, NULL); 184 if (decoded_path == NULL) 185 goto err; 186 /* Don't allow any ".."s in the path, to avoid exposing stuff outside 187 * of the docroot. This test is both overzealous and underzealous: 188 * it forbids aceptable paths like "/this/one..here", but it doesn't 189 * do anything to prevent symlink following." */ 190 if (strstr(decoded_path, "..")) 191 goto err; 192 193 len = strlen(decoded_path)+strlen(docroot)+2; 194 if (!(whole_path = malloc(len))) { 195 perror("malloc"); 196 goto err; 197 } 198 evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path); 199 200 if (stat(whole_path, &st)<0) { 201 goto err; 202 } 203 204 /* This holds the content we're sending. */ 205 evb = evbuffer_new(); 206 207 if (S_ISDIR(st.st_mode)) { 208 /* If it's a directory, read the comments and make a little 209 * index page */ 210 #ifdef WIN32 211 HANDLE d; 212 WIN32_FIND_DATAA ent; 213 char *pattern; 214 size_t dirlen; 215 #else 216 DIR *d; 217 struct dirent *ent; 218 #endif 219 const char *trailing_slash = ""; 220 221 if (!strlen(path) || path[strlen(path)-1] != '/') 222 trailing_slash = "/"; 223 224 #ifdef WIN32 225 dirlen = strlen(whole_path); 226 pattern = malloc(dirlen+3); 227 memcpy(pattern, whole_path, dirlen); 228 pattern[dirlen] = '\\'; 229 pattern[dirlen+1] = '*'; 230 pattern[dirlen+2] = '\0'; 231 d = FindFirstFileA(pattern, &ent); 232 free(pattern); 233 if (d == INVALID_HANDLE_VALUE) 234 goto err; 235 #else 236 if (!(d = opendir(whole_path))) 237 goto err; 238 #endif 239 240 evbuffer_add_printf(evb, "<html>\n <head>\n" 241 " <title>%s</title>\n" 242 " <base href='%s%s%s'>\n" 243 " </head>\n" 244 " <body>\n" 245 " <h1>%s</h1>\n" 246 " <ul>\n", 247 decoded_path, /* XXX html-escape this. */ 248 uri_root, path, /* XXX html-escape this? */ 249 trailing_slash, 250 decoded_path /* XXX html-escape this */); 251 #ifdef WIN32 252 do { 253 const char *name = ent.cFileName; 254 #else 255 while ((ent = readdir(d))) { 256 const char *name = ent->d_name; 257 #endif 258 evbuffer_add_printf(evb, 259 " <li><a href=\"%s\">%s</a>\n", 260 name, name);/* XXX escape this */ 261 #ifdef WIN32 262 } while (FindNextFileA(d, &ent)); 263 #else 264 } 265 #endif 266 evbuffer_add_printf(evb, "</ul></body></html>\n"); 267 #ifdef WIN32 268 CloseHandle(d); 269 #else 270 closedir(d); 271 #endif 272 evhttp_add_header(evhttp_request_get_output_headers(req), 273 "Content-Type", "text/html"); 274 } else { 275 /* Otherwise it's a file; add it to the buffer to get 276 * sent via sendfile */ 277 const char *type = guess_content_type(decoded_path); 278 if ((fd = open(whole_path, O_RDONLY)) < 0) { 279 perror("open"); 280 goto err; 281 } 282 283 if (fstat(fd, &st)<0) { 284 /* Make sure the length still matches, now that we 285 * opened the file :/ */ 286 perror("fstat"); 287 goto err; 288 } 289 evhttp_add_header(evhttp_request_get_output_headers(req), 290 "Content-Type", type); 291 evbuffer_add_file(evb, fd, 0, st.st_size); 292 } 293 294 evhttp_send_reply(req, 200, "OK", evb); 295 goto done; 296 err: 297 evhttp_send_error(req, 404, "Document was not found"); 298 if (fd>=0) 299 close(fd); 300 done: 301 if (decoded) 302 evhttp_uri_free(decoded); 303 if (decoded_path) 304 free(decoded_path); 305 if (whole_path) 306 free(whole_path); 307 if (evb) 308 evbuffer_free(evb); 309 } 310 311 static void 312 syntax(void) 313 { 314 fprintf(stdout, "Syntax: http-server <docroot>\n"); 315 } 316 317 int 318 main(int argc, char **argv) 319 { 320 struct event_base *base; 321 struct evhttp *http; 322 struct evhttp_bound_socket *handle; 323 324 unsigned short port = 0; 325 #ifdef WIN32 326 WSADATA WSAData; 327 WSAStartup(0x101, &WSAData); 328 #else 329 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR) 330 return (1); 331 #endif 332 if (argc < 2) { 333 syntax(); 334 return 1; 335 } 336 337 base = event_base_new(); 338 if (!base) { 339 fprintf(stderr, "Couldn't create an event_base: exiting\n"); 340 return 1; 341 } 342 343 /* Create a new evhttp object to handle requests. */ 344 http = evhttp_new(base); 345 if (!http) { 346 fprintf(stderr, "couldn't create evhttp. Exiting.\n"); 347 return 1; 348 } 349 350 /* The /dump URI will dump all requests to stdout and say 200 ok. */ 351 evhttp_set_cb(http, "/dump", dump_request_cb, NULL); 352 353 /* We want to accept arbitrary requests, so we need to set a "generic" 354 * cb. We can also add callbacks for specific paths. */ 355 evhttp_set_gencb(http, send_document_cb, argv[1]); 356 357 /* Now we tell the evhttp what port to listen on */ 358 handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", port); 359 if (!handle) { 360 fprintf(stderr, "couldn't bind to port %d. Exiting.\n", 361 (int)port); 362 return 1; 363 } 364 365 { 366 /* Extract and display the address we're listening on. */ 367 struct sockaddr_storage ss; 368 evutil_socket_t fd; 369 ev_socklen_t socklen = sizeof(ss); 370 char addrbuf[128]; 371 void *inaddr; 372 const char *addr; 373 int got_port = -1; 374 fd = evhttp_bound_socket_get_fd(handle); 375 memset(&ss, 0, sizeof(ss)); 376 if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) { 377 perror("getsockname() failed"); 378 return 1; 379 } 380 if (ss.ss_family == AF_INET) { 381 got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port); 382 inaddr = &((struct sockaddr_in*)&ss)->sin_addr; 383 } else if (ss.ss_family == AF_INET6) { 384 got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port); 385 inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr; 386 } else { 387 fprintf(stderr, "Weird address family %d\n", 388 ss.ss_family); 389 return 1; 390 } 391 addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf, 392 sizeof(addrbuf)); 393 if (addr) { 394 printf("Listening on %s:%d\n", addr, got_port); 395 evutil_snprintf(uri_root, sizeof(uri_root), 396 "http://%s:%d",addr,got_port); 397 } else { 398 fprintf(stderr, "evutil_inet_ntop failed\n"); 399 return 1; 400 } 401 } 402 403 event_base_dispatch(base); 404 405 return 0; 406 } 407