4 * This is the other half of the webserver. It handles the task of hooking
5 * up HTTP requests with the session 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 spawned.
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);
124 void gets0(int fd, char buf[])
129 buf[strlen(buf) + 1] = 0;
130 read(fd, &buf[strlen(buf)], 1);
131 } while (buf[strlen(buf) - 1] >= 32);
132 buf[strlen(buf) - 1] = 0;
136 * Collapse multiple cookies on one line
138 void req_gets(int sock, char *buf, char *hold)
142 if (strlen(hold) == 0) {
143 client_gets(sock, buf);
149 if (!strncasecmp(buf, "Cookie: ", 8)) {
150 for (a = 0; a < strlen(buf); ++a)
152 sprintf(hold, "Cookie: %s", &buf[a + 1]);
154 while (isspace(hold[8]))
155 strcpy(&hold[8], &hold[9]);
162 * lingering_close() a`la Apache. see
163 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
166 static int lingering_close(int fd)
171 struct timeval tv, start;
173 gettimeofday(&start, NULL);
177 gettimeofday(&tv, NULL);
178 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
179 tv.tv_usec = start.tv_usec - tv.tv_usec;
180 if (tv.tv_usec < 0) {
182 tv.tv_usec += 1000000;
186 i = select(fd + 1, &set, NULL, NULL, &tv);
187 } while (i == -1 && errno == EINTR);
192 i = read(fd, buf, sizeof buf);
193 } while (i != 0 && (i != -1 || errno == EINTR));
202 * This loop gets called once for every HTTP connection made to WebCit. At
203 * this entry point we have an HTTP socket with a browser allegedly on the
204 * other end, but we have not yet bound to a WebCit session.
206 * The job of this function is to locate the correct session and bind to it,
207 * or create a session if necessary and bind to it, then run the WebCit
208 * transaction loop. Afterwards, we unbind from the session. When this
209 * function returns, the worker thread is then free to handle another
212 void context_loop(int sock)
214 struct httprequest *req = NULL;
215 struct httprequest *last = NULL;
216 struct httprequest *hptr;
217 char buf[256], hold[256];
218 int desired_session = 0;
220 struct wcsession *TheSession, *sptr;
223 * Find out what it is that the web browser is asking for
226 req_gets(sock, buf, hold);
227 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
228 cookie_to_stuff(&buf[15], &desired_session,
233 hptr = (struct httprequest *)
234 malloc(sizeof(struct httprequest));
242 strcpy(hptr->line, buf);
244 } while (strlen(buf) > 0);
248 * If requesting a non-root page, there should already be a cookie
249 * set. If there isn't, the client browser has cookies turned off
250 * (or doesn't support them) and we have to barf & bail.
252 strcpy(buf, req->line);
253 if (!strncasecmp(buf, "GET ", 4)) strcpy(buf, &buf[4]);
254 else if (!strncasecmp(buf, "HEAD ", 5)) strcpy(buf, &buf[5]);
255 if (buf[1]==' ') buf[1]=0;
258 * While we're at it, gracefully handle requests for the
261 if (!strncasecmp(buf, "/robots.txt", 11)) {
262 strcpy(req->line, "GET /static/robots.txt HTTP/1.0");
265 /* Do the non-root-cookie check now. */
266 else if ( (strcmp(buf, "/")) && (got_cookie == 0)) {
267 strcpy(req->line, "GET /static/nocookies.html HTTP/1.0");
273 * See if there's an existing session open with the desired ID
276 if (desired_session != 0) {
277 pthread_mutex_lock(&SessionListMutex);
278 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
279 if (sptr->wc_session == desired_session) {
283 pthread_mutex_unlock(&SessionListMutex);
287 * Create a new session if we have to
289 if (TheSession == NULL) {
290 printf("Creating a new session\n");
291 TheSession = (struct wcsession *)
292 malloc(sizeof(struct wcsession));
293 memset(TheSession, 0, sizeof(struct wcsession));
294 TheSession->wc_session = GenerateSessionID();
295 pthread_mutex_init(&TheSession->SessionMutex, NULL);
297 pthread_mutex_lock(&SessionListMutex);
298 TheSession->next = SessionList;
299 SessionList = TheSession;
300 pthread_mutex_unlock(&SessionListMutex);
306 * FIX ... check session integrity here before continuing
313 * Bind to the session and perform the transaction
315 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
316 pthread_setspecific(MyConKey, (void *)TheSession);
317 TheSession->http_sock = sock;
318 TheSession->lastreq = time(NULL); /* log */
319 fprintf(stderr, "%s\n", req->line);
320 session_loop(req); /* perform the requested transaction */
321 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
323 /* Free the request buffer */
324 while (req != NULL) {
331 * Now our HTTP connection is done. Close the socket and exit this
332 * function, so the worker thread can handle a new HTTP connection.
334 lingering_close(sock);