4 * This is the other half of the webserver. It handles the task of hooking
5 * up HTTP requests with the sessions they belong to, using HTTP cookies to
6 * keep track of things. If the HTTP request doesn't belong to any currently
7 * active session, a new session is started.
12 #include "webserver.h"
14 /* Only one thread may manipulate SessionList at a time... */
15 pthread_mutex_t SessionListMutex;
17 struct wcsession *SessionList = NULL;
19 pthread_key_t MyConKey; /* TSD key for MySession() */
22 void free_attachments(struct wcsession *sess) {
23 struct wc_attachment *att;
25 while (sess->first_attachment != NULL) {
26 att = sess->first_attachment;
27 sess->first_attachment = sess->first_attachment->next;
34 void do_housekeeping(void)
36 struct wcsession *sptr, *ss;
37 struct wcsession *sessions_to_kill = NULL;
39 static int num_threads = MIN_WORKER_THREADS;
42 * Lock the session list, moving any candidates for euthanasia into
45 pthread_mutex_lock(&SessionListMutex);
47 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
50 /* Kill idle sessions */
51 if ((time(NULL) - (sptr->lastreq)) >
52 (time_t) WEBCIT_TIMEOUT) {
56 /* Remove sessions flagged for kill */
59 /* remove session from linked list */
60 if (sptr == SessionList) {
61 SessionList = SessionList->next;
63 else for (ss=SessionList;ss!=NULL;ss=ss->next) {
64 if (ss->next == sptr) {
65 ss->next = ss->next->next;
69 sptr->next = sessions_to_kill;
70 sessions_to_kill = sptr;
73 pthread_mutex_unlock(&SessionListMutex);
76 * Now free up and destroy the culled sessions.
78 while (sessions_to_kill != NULL) {
79 lprintf(3, "Destroying session %d\n", sessions_to_kill->wc_session);
80 pthread_mutex_lock(&sessions_to_kill->SessionMutex);
81 close(sessions_to_kill->serv_sock);
82 close(sessions_to_kill->chat_sock);
83 if (sessions_to_kill->preferences != NULL) {
84 free(sessions_to_kill->preferences);
86 if (sessions_to_kill->cache_fold != NULL) {
87 free(sessions_to_kill->cache_fold);
89 free_attachments(sessions_to_kill);
90 pthread_mutex_unlock(&sessions_to_kill->SessionMutex);
91 sptr = sessions_to_kill->next;
92 free(sessions_to_kill);
93 sessions_to_kill = sptr;
98 * If there are more sessions than threads, then we should spawn
99 * more threads ... up to a predefined maximum.
101 while ( (num_sessions > num_threads)
102 && (num_threads <= MAX_WORKER_THREADS) ) {
103 spawn_another_worker_thread();
105 lprintf(3, "There are %d sessions and %d threads active.\n",
106 num_sessions, num_threads);
112 * Wake up occasionally and clean house
114 void housekeeping_loop(void)
117 sleeeeeeeeeep(HOUSEKEEPING);
124 * Generate a unique WebCit session ID (which is not the same thing as the
125 * Citadel session ID).
127 * FIXME ... ensure that session number is truly unique
130 int GenerateSessionID(void)
132 static int seq = (-1);
135 seq = (int) time(NULL);
143 * Collapse multiple cookies on one line
145 int req_gets(int sock, char *buf, char *hold)
149 if (strlen(hold) == 0) {
151 a = client_getln(sock, buf, SIZ);
154 safestrncpy(buf, hold, SIZ);
158 if (!strncasecmp(buf, "Cookie: ", 8)) {
159 for (a = 0; a < strlen(buf); ++a)
161 sprintf(hold, "Cookie: %s", &buf[a + 1]);
163 while (isspace(hold[8]))
164 strcpy(&hold[8], &hold[9]);
173 * lingering_close() a`la Apache. see
174 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
177 int lingering_close(int fd)
182 struct timeval tv, start;
184 gettimeofday(&start, NULL);
188 gettimeofday(&tv, NULL);
189 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
190 tv.tv_usec = start.tv_usec - tv.tv_usec;
191 if (tv.tv_usec < 0) {
193 tv.tv_usec += 1000000;
197 i = select(fd + 1, &set, NULL, NULL, &tv);
198 } while (i == -1 && errno == EINTR);
203 i = read(fd, buf, sizeof buf);
204 } while (i != 0 && (i != -1 || errno == EINTR));
212 * Check for bogus requests coming from (for example) brain-dead
213 * Windoze boxes that are infected with the latest worm-of-the-week.
214 * If we detect one of these, bail out without bothering our Citadel
217 int is_bogus(char *http_cmd) {
219 if (!strncasecmp(http_cmd, "GET /scripts/root.exe", 21)) return(1);
220 if (!strncasecmp(http_cmd, "GET /c/winnt", 12)) return(2);
221 if (!strncasecmp(http_cmd, "GET /MSADC/", 11)) return(3);
223 return(0); /* probably ok */
229 * This loop gets called once for every HTTP connection made to WebCit. At
230 * this entry point we have an HTTP socket with a browser allegedly on the
231 * other end, but we have not yet bound to a WebCit session.
233 * The job of this function is to locate the correct session and bind to it,
234 * or create a session if necessary and bind to it, then run the WebCit
235 * transaction loop. Afterwards, we unbind from the session. When this
236 * function returns, the worker thread is then free to handle another
239 void context_loop(int sock)
241 struct httprequest *req = NULL;
242 struct httprequest *last = NULL;
243 struct httprequest *hptr;
244 char buf[SIZ], hold[SIZ];
245 int desired_session = 0;
248 struct wcsession *TheSession, *sptr;
249 char httpauth_string[SIZ];
250 char httpauth_user[SIZ];
251 char httpauth_pass[SIZ];
254 strcpy(httpauth_string, "");
255 strcpy(httpauth_user, DEFAULT_HTTPAUTH_USER);
256 strcpy(httpauth_pass, DEFAULT_HTTPAUTH_PASS);
259 * Find out what it is that the web browser is asking for
261 memset(hold, 0, sizeof(hold));
263 if (req_gets(sock, buf, hold) < 0) return;
268 if (!strncasecmp(buf, "Accept-encoding:", 16)) {
269 if (strstr(&buf[16], "gzip")) {
275 * Browser-based sessions use cookies for session authentication
277 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
278 cookie_to_stuff(&buf[15], &desired_session,
279 NULL, 0, NULL, 0, NULL, 0);
284 * GroupDAV-based sessions use HTTP authentication
286 if (!strncasecmp(buf, "Authorization: Basic ", 21)) {
287 CtdlDecodeBase64(httpauth_string, &buf[21], strlen(&buf[21]));
288 extract_token(httpauth_user, httpauth_string, 0, ':', sizeof httpauth_user);
289 extract_token(httpauth_pass, httpauth_string, 1, ':', sizeof httpauth_pass);
292 if (!strncasecmp(buf, "If-Modified-Since: ", 19)) {
293 if_modified_since = httpdate_to_timestamp(&buf[19]);
296 /*if (!strncasecmp(buf, "Accept-Language: ", 17)) {
297 httplang_to_locale(&buf[17]);
301 * Read in the request
303 hptr = (struct httprequest *)
304 malloc(sizeof(struct httprequest));
312 safestrncpy(hptr->line, buf, sizeof hptr->line);
314 } while (strlen(buf) > 0);
317 * If the request is prefixed by "/webcit" then chop that off. This
318 * allows a front end web server to forward all /webcit requests to us
319 * while still using the same web server port for other things.
322 ptr = strstr(req->line, " /webcit "); /* Handle "/webcit" */
324 strcpy(ptr+2, ptr+8);
327 ptr = strstr(req->line, " /webcit"); /* Handle "/webcit/" */
329 strcpy(ptr+1, ptr+8);
332 /* Begin parsing the request. */
334 safestrncpy(buf, req->line, sizeof buf);
335 lprintf(5, "HTTP: %s\n", buf);
337 /* Check for bogus requests */
338 if (is_bogus(buf)) goto bail;
341 * Strip out the method, leaving the URL up front...
343 remove_token(buf, 0, ' ');
344 if (buf[1]==' ') buf[1]=0;
347 * While we're at it, gracefully handle requests for the
348 * robots.txt and favicon.ico files.
350 if (!strncasecmp(buf, "/robots.txt", 11)) {
351 strcpy(req->line, "GET /static/robots.txt"
352 "?force_close_session=yes HTTP/1.1");
354 else if (!strncasecmp(buf, "/favicon.ico", 12)) {
355 strcpy(req->line, "GET /static/favicon.ico");
358 /* These are the URL's which may be executed without a
359 * session cookie already set. If it's not one of these,
360 * force the session to close because cookies are
361 * probably disabled on the client browser.
363 else if ( (strcmp(buf, "/"))
364 && (strncasecmp(buf, "/listsub", 8))
365 && (strncasecmp(buf, "/freebusy", 9))
366 && (strncasecmp(buf, "/do_logout", 10))
367 && (strncasecmp(buf, "/groupdav", 9))
368 && (strncasecmp(buf, "/static", 7))
369 && (strncasecmp(buf, "/rss", 4))
370 && (got_cookie == 0)) {
371 strcpy(req->line, "GET /static/nocookies.html"
372 "?force_close_session=yes HTTP/1.1");
376 * See if there's an existing session open with the desired ID or user/pass
380 if (TheSession == NULL) {
381 pthread_mutex_lock(&SessionListMutex);
382 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
384 /* If HTTP-AUTH, look for a session with matching credentials */
385 if ( (strlen(httpauth_user) > 0)
386 &&(!strcasecmp(sptr->httpauth_user, httpauth_user))
387 &&(!strcasecmp(sptr->httpauth_pass, httpauth_pass)) ) {
391 /* If cookie-session, look for a session with matching session ID */
392 if ( (desired_session != 0) && (sptr->wc_session == desired_session)) {
397 pthread_mutex_unlock(&SessionListMutex);
401 * Create a new session if we have to
403 if (TheSession == NULL) {
404 lprintf(3, "Creating a new session\n");
405 TheSession = (struct wcsession *)
406 malloc(sizeof(struct wcsession));
407 memset(TheSession, 0, sizeof(struct wcsession));
408 TheSession->serv_sock = (-1);
409 TheSession->chat_sock = (-1);
410 TheSession->wc_session = GenerateSessionID();
411 strcpy(TheSession->httpauth_user, httpauth_user);
412 strcpy(TheSession->httpauth_pass, httpauth_pass);
413 pthread_mutex_init(&TheSession->SessionMutex, NULL);
415 pthread_mutex_lock(&SessionListMutex);
416 TheSession->next = SessionList;
417 SessionList = TheSession;
418 pthread_mutex_unlock(&SessionListMutex);
422 * A future improvement might be to check the session integrity
423 * at this point before continuing.
427 * Bind to the session and perform the transaction
429 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
430 pthread_setspecific(MyConKey, (void *)TheSession);
431 TheSession->http_sock = sock;
432 TheSession->lastreq = time(NULL); /* log */
433 TheSession->gzip_ok = gzip_ok;
434 session_loop(req); /* do transaction */
435 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
437 /* Free the request buffer */
438 bail: while (req != NULL) {
444 /* Free up any session-local substitution variables which
445 * were set during this transaction
447 clear_local_substs();