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 pthread_mutex_unlock(&session_to_kill->SessionMutex);
86 free(session_to_kill);
89 } while (session_to_kill != NULL);
94 * Wake up occasionally and clean house
96 void housekeeping_loop(void)
106 * Generate a unique WebCit session ID (which is not the same thing as the
107 * Citadel session ID).
109 * FIX ... ensure that session number is truly unique
112 int GenerateSessionID(void)
114 static int seq = (-1);
117 seq = (int) time(NULL);
125 * Collapse multiple cookies on one line
127 int req_gets(int sock, char *buf, char *hold)
131 if (strlen(hold) == 0) {
133 a = client_gets(sock, buf);
140 if (!strncasecmp(buf, "Cookie: ", 8)) {
141 for (a = 0; a < strlen(buf); ++a)
143 sprintf(hold, "Cookie: %s", &buf[a + 1]);
145 while (isspace(hold[8]))
146 strcpy(&hold[8], &hold[9]);
154 * lingering_close() a`la Apache. see
155 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
158 int lingering_close(int fd)
163 struct timeval tv, start;
165 gettimeofday(&start, NULL);
169 gettimeofday(&tv, NULL);
170 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
171 tv.tv_usec = start.tv_usec - tv.tv_usec;
172 if (tv.tv_usec < 0) {
174 tv.tv_usec += 1000000;
178 i = select(fd + 1, &set, NULL, NULL, &tv);
179 } while (i == -1 && errno == EINTR);
184 i = read(fd, buf, sizeof buf);
185 } while (i != 0 && (i != -1 || errno == EINTR));
193 * Check for bogus requests coming from (for example) brain-dead
194 * Windoze boxes that are infected with the latest worm-of-the-week.
195 * If we detect one of these, bail out without bothering our Citadel
198 int is_bogus(char *http_cmd) {
200 if (!strncasecmp(http_cmd, "GET /scripts/root.exe", 21)) return(1);
201 if (!strncasecmp(http_cmd, "GET /c/winnt", 12)) return(2);
202 if (!strncasecmp(http_cmd, "GET /MSADC/", 11)) return(3);
204 return(0); /* probably ok */
210 * This loop gets called once for every HTTP connection made to WebCit. At
211 * this entry point we have an HTTP socket with a browser allegedly on the
212 * other end, but we have not yet bound to a WebCit session.
214 * The job of this function is to locate the correct session and bind to it,
215 * or create a session if necessary and bind to it, then run the WebCit
216 * transaction loop. Afterwards, we unbind from the session. When this
217 * function returns, the worker thread is then free to handle another
220 void context_loop(int sock)
222 struct httprequest *req = NULL;
223 struct httprequest *last = NULL;
224 struct httprequest *hptr;
225 char buf[SIZ], hold[SIZ];
226 int desired_session = 0;
228 struct wcsession *TheSession, *sptr;
231 * Find out what it is that the web browser is asking for
233 memset(hold, 0, sizeof(hold));
235 if (req_gets(sock, buf, hold) < 0) return;
236 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
237 cookie_to_stuff(&buf[15], &desired_session,
242 hptr = (struct httprequest *)
243 malloc(sizeof(struct httprequest));
251 strcpy(hptr->line, buf);
253 } while (strlen(buf) > 0);
255 strcpy(buf, req->line);
256 fprintf(stderr, "%s\n", buf);
258 /* Check for bogus requests */
259 if (is_bogus(buf)) goto bail;
262 * If requesting a non-root page, there should already be a cookie
263 * set. If there isn't, the client browser has cookies turned off
264 * (or doesn't support them) and we have to barf & bail.
266 if (!strncasecmp(buf, "GET ", 4)) strcpy(buf, &buf[4]);
267 else if (!strncasecmp(buf, "HEAD ", 5)) strcpy(buf, &buf[5]);
268 if (buf[1]==' ') buf[1]=0;
271 * While we're at it, gracefully handle requests for the
274 if (!strncasecmp(buf, "/robots.txt", 11)) {
275 strcpy(req->line, "GET /static/robots.txt"
276 "?force_close_session=yes HTTP/1.0");
279 /* Do the non-root-cookie check now. */
280 else if ( (strcmp(buf, "/")) && (got_cookie == 0)) {
281 strcpy(req->line, "GET /static/nocookies.html"
282 "?force_close_session=yes HTTP/1.0");
288 * See if there's an existing session open with the desired ID
291 if (desired_session != 0) {
292 pthread_mutex_lock(&SessionListMutex);
293 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
294 if (sptr->wc_session == desired_session) {
298 pthread_mutex_unlock(&SessionListMutex);
302 * Create a new session if we have to
304 if (TheSession == NULL) {
305 fprintf(stderr, "Creating a new session\n");
306 TheSession = (struct wcsession *)
307 malloc(sizeof(struct wcsession));
308 memset(TheSession, 0, sizeof(struct wcsession));
309 TheSession->wc_session = GenerateSessionID();
310 pthread_mutex_init(&TheSession->SessionMutex, NULL);
312 pthread_mutex_lock(&SessionListMutex);
313 TheSession->next = SessionList;
314 SessionList = TheSession;
315 pthread_mutex_unlock(&SessionListMutex);
321 * FIX ... check session integrity here before continuing
327 * Bind to the session and perform the transaction
329 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
330 pthread_setspecific(MyConKey, (void *)TheSession);
331 TheSession->http_sock = sock;
332 TheSession->lastreq = time(NULL); /* log */
333 session_loop(req); /* perform the requested transaction */
334 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
336 /* Free the request buffer */
337 bail: while (req != NULL) {