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.
22 #include <sys/types.h>
24 #include <sys/socket.h>
25 #ifdef HAVE_SYS_TIME_H
31 #include <netinet/in.h>
39 #include "webserver.h"
41 /* Only one thread may manipulate SessionList at a time... */
42 pthread_mutex_t SessionListMutex;
44 struct wcsession *SessionList = NULL;
46 pthread_key_t MyConKey; /* TSD key for MySession() */
48 void do_housekeeping(void)
50 struct wcsession *sptr, *ss, *session_to_kill;
53 session_to_kill = NULL;
54 pthread_mutex_lock(&SessionListMutex);
55 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
57 /* Kill idle sessions */
58 if ((time(NULL) - (sptr->lastreq)) >
59 (time_t) WEBCIT_TIMEOUT) {
63 /* Remove sessions flagged for kill */
66 /* remove session from linked list */
67 if (sptr == SessionList) {
68 SessionList = SessionList->next;
70 else for (ss=SessionList;ss!=NULL;ss=ss->next) {
71 if (ss->next == sptr) {
72 ss->next = ss->next->next;
76 session_to_kill = sptr;
80 BREAKOUT: pthread_mutex_unlock(&SessionListMutex);
82 if (session_to_kill != NULL) {
83 pthread_mutex_lock(&session_to_kill->SessionMutex);
84 close(session_to_kill->serv_sock);
85 if (session_to_kill->preferences != NULL) {
86 free(session_to_kill->preferences);
88 pthread_mutex_unlock(&session_to_kill->SessionMutex);
89 free(session_to_kill);
92 } while (session_to_kill != NULL);
97 * Wake up occasionally and clean house
99 void housekeeping_loop(void)
109 * Generate a unique WebCit session ID (which is not the same thing as the
110 * Citadel session ID).
112 * FIX ... ensure that session number is truly unique
115 int GenerateSessionID(void)
117 static int seq = (-1);
120 seq = (int) time(NULL);
128 * Collapse multiple cookies on one line
130 int req_gets(int sock, char *buf, char *hold)
134 if (strlen(hold) == 0) {
136 a = client_gets(sock, buf);
143 if (!strncasecmp(buf, "Cookie: ", 8)) {
144 for (a = 0; a < strlen(buf); ++a)
146 sprintf(hold, "Cookie: %s", &buf[a + 1]);
148 while (isspace(hold[8]))
149 strcpy(&hold[8], &hold[9]);
157 * lingering_close() a`la Apache. see
158 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
161 int lingering_close(int fd)
166 struct timeval tv, start;
168 gettimeofday(&start, NULL);
172 gettimeofday(&tv, NULL);
173 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
174 tv.tv_usec = start.tv_usec - tv.tv_usec;
175 if (tv.tv_usec < 0) {
177 tv.tv_usec += 1000000;
181 i = select(fd + 1, &set, NULL, NULL, &tv);
182 } while (i == -1 && errno == EINTR);
187 i = read(fd, buf, sizeof buf);
188 } while (i != 0 && (i != -1 || errno == EINTR));
196 * Check for bogus requests coming from (for example) brain-dead
197 * Windoze boxes that are infected with the latest worm-of-the-week.
198 * If we detect one of these, bail out without bothering our Citadel
201 int is_bogus(char *http_cmd) {
203 if (!strncasecmp(http_cmd, "GET /scripts/root.exe", 21)) return(1);
204 if (!strncasecmp(http_cmd, "GET /c/winnt", 12)) return(2);
205 if (!strncasecmp(http_cmd, "GET /MSADC/", 11)) return(3);
207 return(0); /* probably ok */
213 * This loop gets called once for every HTTP connection made to WebCit. At
214 * this entry point we have an HTTP socket with a browser allegedly on the
215 * other end, but we have not yet bound to a WebCit session.
217 * The job of this function is to locate the correct session and bind to it,
218 * or create a session if necessary and bind to it, then run the WebCit
219 * transaction loop. Afterwards, we unbind from the session. When this
220 * function returns, the worker thread is then free to handle another
223 void context_loop(int sock)
225 struct httprequest *req = NULL;
226 struct httprequest *last = NULL;
227 struct httprequest *hptr;
228 char buf[SIZ], hold[SIZ];
229 int desired_session = 0;
231 struct wcsession *TheSession, *sptr;
234 * Find out what it is that the web browser is asking for
236 memset(hold, 0, sizeof(hold));
238 if (req_gets(sock, buf, hold) < 0) return;
239 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
240 cookie_to_stuff(&buf[15], &desired_session,
245 hptr = (struct httprequest *)
246 malloc(sizeof(struct httprequest));
254 strcpy(hptr->line, buf);
256 } while (strlen(buf) > 0);
258 strcpy(buf, req->line);
259 lprintf(5, "HTTP: %s\n", buf);
261 /* Check for bogus requests */
262 if (is_bogus(buf)) goto bail;
265 * If requesting a non-root page, there should already be a cookie
266 * set. If there isn't, the client browser has cookies turned off
267 * (or doesn't support them) and we have to barf & bail.
269 if (!strncasecmp(buf, "GET ", 4)) strcpy(buf, &buf[4]);
270 else if (!strncasecmp(buf, "HEAD ", 5)) strcpy(buf, &buf[5]);
271 if (buf[1]==' ') buf[1]=0;
274 * While we're at it, gracefully handle requests for the
277 if (!strncasecmp(buf, "/robots.txt", 11)) {
278 strcpy(req->line, "GET /static/robots.txt"
279 "?force_close_session=yes HTTP/1.0");
282 /* Do the non-root-cookie check now. */
283 else if ( (strcmp(buf, "/")) && (got_cookie == 0)) {
284 strcpy(req->line, "GET /static/nocookies.html"
285 "?force_close_session=yes HTTP/1.0");
290 * See if there's an existing session open with the desired ID
293 if (desired_session != 0) {
294 pthread_mutex_lock(&SessionListMutex);
295 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
296 if (sptr->wc_session == desired_session) {
300 pthread_mutex_unlock(&SessionListMutex);
304 * Create a new session if we have to
306 if (TheSession == NULL) {
307 lprintf(3, "Creating a new session\n");
308 TheSession = (struct wcsession *)
309 malloc(sizeof(struct wcsession));
310 memset(TheSession, 0, sizeof(struct wcsession));
311 TheSession->wc_session = GenerateSessionID();
312 pthread_mutex_init(&TheSession->SessionMutex, NULL);
314 pthread_mutex_lock(&SessionListMutex);
315 TheSession->next = SessionList;
316 SessionList = TheSession;
317 pthread_mutex_unlock(&SessionListMutex);
323 * FIX ... check session integrity here before continuing
329 * Bind to the session and perform the transaction
331 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
332 pthread_setspecific(MyConKey, (void *)TheSession);
333 TheSession->http_sock = sock;
334 TheSession->lastreq = time(NULL); /* log */
335 session_loop(req); /* perform the requested transaction */
336 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
338 /* Free the request buffer */
339 bail: while (req != NULL) {