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.
21 #include <sys/types.h>
23 #include <sys/socket.h>
24 #ifdef HAVE_SYS_TIME_H
30 #include <netinet/in.h>
38 #include "webserver.h"
40 /* Only one thread may manipulate SessionList at a time... */
41 pthread_mutex_t SessionListMutex;
43 struct wcsession *SessionList = NULL;
45 pthread_key_t MyConKey; /* TSD key for MySession() */
48 void free_attachments(struct wcsession *sess) {
49 struct wc_attachment *att;
51 while (sess->first_attachment != NULL) {
52 att = sess->first_attachment;
53 sess->first_attachment = sess->first_attachment->next;
60 void do_housekeeping(void)
62 struct wcsession *sptr, *ss, *session_to_kill;
64 static int num_threads = MIN_WORKER_THREADS;
67 session_to_kill = NULL;
68 pthread_mutex_lock(&SessionListMutex);
70 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
73 /* Kill idle sessions */
74 if ((time(NULL) - (sptr->lastreq)) >
75 (time_t) WEBCIT_TIMEOUT) {
79 /* Remove sessions flagged for kill */
82 lprintf(3, "Destroying session %d\n",
85 /* remove session from linked list */
86 if (sptr == SessionList) {
87 SessionList = SessionList->next;
89 else for (ss=SessionList;ss!=NULL;ss=ss->next) {
90 if (ss->next == sptr) {
91 ss->next = ss->next->next;
95 session_to_kill = sptr;
99 BREAKOUT: pthread_mutex_unlock(&SessionListMutex);
101 if (session_to_kill != NULL) {
102 pthread_mutex_lock(&session_to_kill->SessionMutex);
103 close(session_to_kill->serv_sock);
104 close(session_to_kill->chat_sock);
105 if (session_to_kill->preferences != NULL) {
106 free(session_to_kill->preferences);
108 free_attachments(session_to_kill);
109 pthread_mutex_unlock(&session_to_kill->SessionMutex);
110 free(session_to_kill);
113 } while (session_to_kill != NULL);
116 * See if we need more worker threads
118 while ( (num_sessions > num_threads)
119 && (num_threads <= MAX_WORKER_THREADS) ) {
120 spawn_another_worker_thread();
122 lprintf(3, "There are %d sessions and %d threads active.\n",
123 num_sessions, num_threads);
129 * Wake up occasionally and clean house
131 void housekeeping_loop(void)
134 sleeeeeeeeeep(HOUSEKEEPING);
141 * Generate a unique WebCit session ID (which is not the same thing as the
142 * Citadel session ID).
144 * FIXME ... ensure that session number is truly unique
147 int GenerateSessionID(void)
149 static int seq = (-1);
152 seq = (int) time(NULL);
160 * Collapse multiple cookies on one line
162 int req_gets(int sock, char *buf, char *hold)
166 if (strlen(hold) == 0) {
168 a = client_gets(sock, buf);
171 safestrncpy(buf, hold, SIZ);
175 if (!strncasecmp(buf, "Cookie: ", 8)) {
176 for (a = 0; a < strlen(buf); ++a)
178 sprintf(hold, "Cookie: %s", &buf[a + 1]);
180 while (isspace(hold[8]))
181 strcpy(&hold[8], &hold[9]);
190 * lingering_close() a`la Apache. see
191 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
194 int lingering_close(int fd)
199 struct timeval tv, start;
201 gettimeofday(&start, NULL);
205 gettimeofday(&tv, NULL);
206 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
207 tv.tv_usec = start.tv_usec - tv.tv_usec;
208 if (tv.tv_usec < 0) {
210 tv.tv_usec += 1000000;
214 i = select(fd + 1, &set, NULL, NULL, &tv);
215 } while (i == -1 && errno == EINTR);
220 i = read(fd, buf, sizeof buf);
221 } while (i != 0 && (i != -1 || errno == EINTR));
229 * Check for bogus requests coming from (for example) brain-dead
230 * Windoze boxes that are infected with the latest worm-of-the-week.
231 * If we detect one of these, bail out without bothering our Citadel
234 int is_bogus(char *http_cmd) {
236 if (!strncasecmp(http_cmd, "GET /scripts/root.exe", 21)) return(1);
237 if (!strncasecmp(http_cmd, "GET /c/winnt", 12)) return(2);
238 if (!strncasecmp(http_cmd, "GET /MSADC/", 11)) return(3);
240 return(0); /* probably ok */
246 * This loop gets called once for every HTTP connection made to WebCit. At
247 * this entry point we have an HTTP socket with a browser allegedly on the
248 * other end, but we have not yet bound to a WebCit session.
250 * The job of this function is to locate the correct session and bind to it,
251 * or create a session if necessary and bind to it, then run the WebCit
252 * transaction loop. Afterwards, we unbind from the session. When this
253 * function returns, the worker thread is then free to handle another
256 void context_loop(int sock)
258 struct httprequest *req = NULL;
259 struct httprequest *last = NULL;
260 struct httprequest *hptr;
261 char buf[SIZ], hold[SIZ];
262 int desired_session = 0;
264 struct wcsession *TheSession, *sptr;
265 char httpauth_string[SIZ];
266 char httpauth_user[SIZ];
267 char httpauth_pass[SIZ];
269 strcpy(httpauth_string, "");
270 strcpy(httpauth_user, "");
271 strcpy(httpauth_pass, "");
274 * Find out what it is that the web browser is asking for
276 memset(hold, 0, sizeof(hold));
278 if (req_gets(sock, buf, hold) < 0) return;
281 * Browser-based sessions use cookies for session authentication
283 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
284 cookie_to_stuff(&buf[15], &desired_session,
290 * GroupDAV-based sessions use HTTP authentication
292 if (!strncasecmp(buf, "Authorization: Basic ", 21)) {
293 CtdlDecodeBase64(httpauth_string, &buf[21], strlen(&buf[21]));
294 extract_token(httpauth_user, httpauth_string, 0, ':');
295 extract_token(httpauth_pass, httpauth_string, 1, ':');
299 * Read in the request
301 hptr = (struct httprequest *)
302 malloc(sizeof(struct httprequest));
310 safestrncpy(hptr->line, buf, sizeof hptr->line);
312 } while (strlen(buf) > 0);
314 safestrncpy(buf, req->line, sizeof buf);
315 lprintf(5, "HTTP: %s\n", buf);
317 /* Check for bogus requests */
318 if (is_bogus(buf)) goto bail;
321 * If requesting a non-root page, there should already be a cookie
322 * set. If there isn't, the client browser has cookies turned off
323 * (or doesn't support them) and we have to barf & bail.
325 remove_token(buf, 0, ' ');
326 if (buf[1]==' ') buf[1]=0;
329 * While we're at it, gracefully handle requests for the
330 * robots.txt and favicon.ico files.
332 if (!strncasecmp(buf, "/robots.txt", 11)) {
333 strcpy(req->line, "GET /static/robots.txt"
334 "?force_close_session=yes HTTP/1.0");
336 else if (!strncasecmp(buf, "/favicon.ico", 12)) {
337 strcpy(req->line, "GET /static/favicon.ico");
340 /* These are the URL's which may be executed without a
341 * session cookie already set. If it's not one of these,
342 * force the session to close because cookies are
343 * probably disabled on the client browser.
345 else if ( (strcmp(buf, "/"))
346 && (strncasecmp(buf, "/listsub", 8))
347 && (strncasecmp(buf, "/freebusy", 9))
348 && (strncasecmp(buf, "/do_logout", 10))
349 && (strncasecmp(buf, "/groupdav", 9))
350 && (got_cookie == 0)) {
351 strcpy(req->line, "GET /static/nocookies.html"
352 "?force_close_session=yes HTTP/1.0");
356 * See if there's an existing session open with the desired ID or user/pass
360 if ( (TheSession == NULL) && (strlen(httpauth_user) > 0) ) {
361 pthread_mutex_lock(&SessionListMutex);
362 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
363 if ( (!strcasecmp(sptr->httpauth_user, httpauth_user))
364 &&(!strcasecmp(sptr->httpauth_pass, httpauth_pass)) ) {
368 pthread_mutex_unlock(&SessionListMutex);
371 if ( (TheSession == NULL) && (desired_session != 0) ) {
372 pthread_mutex_lock(&SessionListMutex);
373 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
374 if (sptr->wc_session == desired_session) {
378 pthread_mutex_unlock(&SessionListMutex);
382 * Create a new session if we have to
384 if (TheSession == NULL) {
385 lprintf(3, "Creating a new session\n");
386 TheSession = (struct wcsession *)
387 malloc(sizeof(struct wcsession));
388 memset(TheSession, 0, sizeof(struct wcsession));
389 TheSession->serv_sock = (-1);
390 TheSession->chat_sock = (-1);
391 TheSession->wc_session = GenerateSessionID();
392 strcpy(TheSession->httpauth_user, httpauth_user);
393 strcpy(TheSession->httpauth_pass, httpauth_pass);
394 pthread_mutex_init(&TheSession->SessionMutex, NULL);
396 pthread_mutex_lock(&SessionListMutex);
397 TheSession->next = SessionList;
398 SessionList = TheSession;
399 pthread_mutex_unlock(&SessionListMutex);
403 * A future improvement might be to check the session integrity
404 * at this point before continuing.
408 * Bind to the session and perform the transaction
410 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
411 pthread_setspecific(MyConKey, (void *)TheSession);
412 TheSession->http_sock = sock;
413 TheSession->lastreq = time(NULL); /* log */
414 session_loop(req); /* do transaction */
415 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
417 /* Free the request buffer */
418 bail: while (req != NULL) {
424 /* Free up any session-local substitution variables which
425 * were set during this transaction
427 clear_local_substs();