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