2 A trivial static http webserver using Libevent's evhttp.
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!
13 #include <sys/types.h>
24 #include <sys/socket.h>
31 #include <event2/event.h>
32 #include <event2/http.h>
33 #include <event2/buffer.h>
34 #include <event2/util.h>
35 #include <event2/keyvalq_struct.h>
37 #ifdef _EVENT_HAVE_NETINET_IN_H
38 #include <netinet/in.h>
46 #define O_RDONLY _O_RDONLY
51 static const struct table_entry {
52 const char *extension;
53 const char *content_type;
54 } content_type_table[] = {
55 { "txt", "text/plain" },
56 { "c", "text/plain" },
57 { "h", "text/plain" },
58 { "html", "text/html" },
59 { "htm", "text/htm" },
60 { "css", "text/css" },
61 { "gif", "image/gif" },
62 { "jpg", "image/jpeg" },
63 { "jpeg", "image/jpeg" },
64 { "png", "image/png" },
65 { "pdf", "application/pdf" },
66 { "ps", "application/postsript" },
70 /* Try to guess a good content-type for 'path' */
72 guess_content_type(const char *path)
74 const char *last_period, *extension;
75 const struct table_entry *ent;
76 last_period = strrchr(path, '.');
77 if (!last_period || strchr(last_period, '/'))
78 goto not_found; /* no exension */
79 extension = last_period + 1;
80 for (ent = &content_type_table[0]; ent->extension; ++ent) {
81 if (!evutil_ascii_strcasecmp(ent->extension, extension))
82 return ent->content_type;
86 return "application/misc";
89 /* Callback used for the /dump URI, and for every non-GET request:
90 * dumps all information to stdout and gives back a trivial 200 ok */
92 dump_request_cb(struct evhttp_request *req, void *arg)
95 struct evkeyvalq *headers;
96 struct evkeyval *header;
99 switch (evhttp_request_get_command(req)) {
100 case EVHTTP_REQ_GET: cmdtype = "GET"; break;
101 case EVHTTP_REQ_POST: cmdtype = "POST"; break;
102 case EVHTTP_REQ_HEAD: cmdtype = "HEAD"; break;
103 case EVHTTP_REQ_PUT: cmdtype = "PUT"; break;
104 case EVHTTP_REQ_DELETE: cmdtype = "DELETE"; break;
105 case EVHTTP_REQ_OPTIONS: cmdtype = "OPTIONS"; break;
106 case EVHTTP_REQ_TRACE: cmdtype = "TRACE"; break;
107 case EVHTTP_REQ_CONNECT: cmdtype = "CONNECT"; break;
108 case EVHTTP_REQ_PATCH: cmdtype = "PATCH"; break;
109 default: cmdtype = "unknown"; break;
112 printf("Received a %s request for %s\nHeaders:\n",
113 cmdtype, evhttp_request_get_uri(req));
115 headers = evhttp_request_get_input_headers(req);
116 for (header = headers->tqh_first; header;
117 header = header->next.tqe_next) {
118 printf(" %s: %s\n", header->key, header->value);
121 buf = evhttp_request_get_input_buffer(req);
122 puts("Input data: <<<");
123 while (evbuffer_get_length(buf)) {
126 n = evbuffer_remove(buf, cbuf, sizeof(buf)-1);
127 fwrite(cbuf, 1, n, stdout);
131 evhttp_send_reply(req, 200, "OK", NULL);
134 /* This callback gets invoked when we get any http request that doesn't match
135 * any other callback. Like any evhttp server callback, it has a simple job:
136 * it must eventually call evhttp_send_error() or evhttp_send_reply().
139 send_document_cb(struct evhttp_request *req, void *arg)
141 struct evbuffer *evb;
142 const char *docroot = arg;
143 const char *uri = evhttp_request_get_uri(req);
144 struct evhttp_uri *decoded = NULL;
147 char *whole_path = NULL;
152 if (evhttp_request_get_command(req) != EVHTTP_REQ_GET) {
153 dump_request_cb(req, arg);
157 printf("Got a GET request for <%s>\n", uri);
160 decoded = evhttp_uri_parse(uri);
162 printf("It's not a good URI. Sending BADREQUEST\n");
163 evhttp_send_error(req, HTTP_BADREQUEST, 0);
167 /* Let's see what path the user asked for. */
168 path = evhttp_uri_get_path(decoded);
169 if (!path) path = "/";
171 /* We need to decode it, to see what path the user really wanted. */
172 decoded_path = evhttp_uridecode(path, 0, NULL);
173 /* Don't allow any ".."s in the path, to avoid exposing stuff outside
174 * of the docroot. This test is both overzealous and underzealous:
175 * it forbids aceptable paths like "/this/one..here", but it doesn't
176 * do anything to prevent symlink following." */
177 if (strstr(decoded_path, ".."))
180 len = strlen(decoded_path)+strlen(docroot)+2;
181 if (!(whole_path = malloc(len))) {
185 evutil_snprintf(whole_path, len, "%s/%s", docroot, decoded_path);
187 if (stat(whole_path, &st)<0) {
191 /* This holds the content we're sending. */
192 evb = evbuffer_new();
194 if (S_ISDIR(st.st_mode)) {
195 /* If it's a directory, read the comments and make a little
199 WIN32_FIND_DATAA ent;
206 const char *trailing_slash = "";
208 if (!strlen(path) || path[strlen(path)-1] != '/')
209 trailing_slash = "/";
212 dirlen = strlen(whole_path);
213 pattern = malloc(dirlen+3);
214 memcpy(pattern, whole_path, dirlen);
215 pattern[dirlen] = '\\';
216 pattern[dirlen+1] = '*';
217 pattern[dirlen+2] = '\0';
218 d = FindFirstFileA(pattern, &ent);
220 if (d == INVALID_HANDLE_VALUE)
223 if (!(d = opendir(whole_path)))
228 evbuffer_add_printf(evb, "<html>\n <head>\n"
229 " <title>%s</title>\n"
230 " <base href='%s%s%s'>\n"
235 decoded_path, /* XXX html-escape this. */
236 uri_root, path, /* XXX html-escape this? */
238 decoded_path /* XXX html-escape this */);
241 const char *name = ent.cFileName;
243 while ((ent = readdir(d))) {
244 const char *name = ent->d_name;
246 evbuffer_add_printf(evb,
247 " <li><a href=\"%s\">%s</a>\n",
248 name, name);/* XXX escape this */
250 } while (FindNextFileA(d, &ent));
254 evbuffer_add_printf(evb, "</ul></body></html>\n");
260 evhttp_add_header(evhttp_request_get_output_headers(req),
261 "Content-Type", "text/html");
263 /* Otherwise it's a file; add it to the buffer to get
264 * sent via sendfile */
265 const char *type = guess_content_type(decoded_path);
266 if ((fd = open(whole_path, O_RDONLY)) < 0) {
271 if (fstat(fd, &st)<0) {
272 /* Make sure the length still matches, now that we
273 * opened the file :/ */
277 evhttp_add_header(evhttp_request_get_output_headers(req),
278 "Content-Type", type);
279 evbuffer_add_file(evb, fd, 0, st.st_size);
282 evhttp_send_reply(req, 200, "OK", evb);
286 evhttp_send_error(req, 404, "Document was not found");
290 evhttp_uri_free(decoded);
300 fprintf(stdout, "Syntax: http-server <docroot>\n");
304 main(int argc, char **argv)
306 struct event_base *base;
308 struct evhttp_bound_socket *handle;
310 unsigned short port = 0;
313 WSAStartup(0x101, &WSAData);
315 if (signal(SIGPIPE, SIG_IGN) == SIG_ERR)
323 base = event_base_new();
325 fprintf(stderr, "Couldn't create an event_base: exiting\n");
329 /* Create a new evhttp object to handle requests. */
330 http = evhttp_new(base);
332 fprintf(stderr, "couldn't create evhttp. Exiting.\n");
336 /* The /dump URI will dump all requests to stdout and say 200 ok. */
337 evhttp_set_cb(http, "/dump", dump_request_cb, NULL);
339 /* We want to accept arbitrary requests, so we need to set a "generic"
340 * cb. We can also add callbacks for specific paths. */
341 evhttp_set_gencb(http, send_document_cb, argv[1]);
343 /* Now we tell the evhttp what port to listen on */
344 handle = evhttp_bind_socket_with_handle(http, "0.0.0.0", port);
346 fprintf(stderr, "couldn't bind to port %d. Exiting.\n",
352 /* Extract and display the address we're listening on. */
353 struct sockaddr_storage ss;
355 ev_socklen_t socklen = sizeof(ss);
360 fd = evhttp_bound_socket_get_fd(handle);
361 memset(&ss, 0, sizeof(ss));
362 if (getsockname(fd, (struct sockaddr *)&ss, &socklen)) {
363 perror("getsockname() failed");
366 if (ss.ss_family == AF_INET) {
367 got_port = ntohs(((struct sockaddr_in*)&ss)->sin_port);
368 inaddr = &((struct sockaddr_in*)&ss)->sin_addr;
369 } else if (ss.ss_family == AF_INET6) {
370 got_port = ntohs(((struct sockaddr_in6*)&ss)->sin6_port);
371 inaddr = &((struct sockaddr_in6*)&ss)->sin6_addr;
373 fprintf(stderr, "Weird address family %d\n",
377 addr = evutil_inet_ntop(ss.ss_family, inaddr, addrbuf,
380 printf("Listening on %s:%d\n", addr, got_port);
381 evutil_snprintf(uri_root, sizeof(uri_root),
382 "http://%s:%d",addr,got_port);
384 fprintf(stderr, "evutil_inet_ntop failed\n");
389 event_base_dispatch(base);