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, *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 */
65 remove session from linked list
66 session_to_kill = sptr;
70 BREAKOUT: pthread_mutex_unlock(&SessionListMutex);
72 if (session_to_kill != NULL) {
73 pthread_mutex_lock(&session_to_kill->SessionMutex);
74 close(session_to_kill->serv_sock);
75 pthread_mutex_unlock(&session_to_kill->SessionMutex);
76 free(session_to_kill);
79 } while (session_to_kill != NULL);
84 * Wake up occasionally and clean house
86 void housekeeping_loop(void)
96 * Generate a unique WebCit session ID (which is not the same thing as the
97 * Citadel session ID).
99 * FIX ... ensure that session number is truly unique
102 int GenerateSessionID(void)
104 static int seq = (-1);
107 seq = (int) time(NULL);
114 void gets0(int fd, char buf[])
119 buf[strlen(buf) + 1] = 0;
120 read(fd, &buf[strlen(buf)], 1);
121 } while (buf[strlen(buf) - 1] >= 32);
122 buf[strlen(buf) - 1] = 0;
126 * Collapse multiple cookies on one line
128 void req_gets(int sock, char *buf, char *hold)
132 if (strlen(hold) == 0) {
133 client_gets(sock, buf);
139 if (!strncasecmp(buf, "Cookie: ", 8)) {
140 for (a = 0; a < strlen(buf); ++a)
142 sprintf(hold, "Cookie: %s", &buf[a + 1]);
144 while (isspace(hold[8]))
145 strcpy(&hold[8], &hold[9]);
152 * lingering_close() a`la Apache. see
153 * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
156 static int lingering_close(int fd)
161 struct timeval tv, start;
163 gettimeofday(&start, NULL);
167 gettimeofday(&tv, NULL);
168 tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
169 tv.tv_usec = start.tv_usec - tv.tv_usec;
170 if (tv.tv_usec < 0) {
172 tv.tv_usec += 1000000;
176 i = select(fd + 1, &set, NULL, NULL, &tv);
177 } while (i == -1 && errno == EINTR);
182 i = read(fd, buf, sizeof buf);
183 } while (i != 0 && (i != -1 || errno == EINTR));
192 * This loop gets called once for every HTTP connection made to WebCit. At
193 * this entry point we have an HTTP socket with a browser allegedly on the
194 * other end, but we have not yet bound to a WebCit session.
196 * The job of this function is to locate the correct session and bind to it,
197 * or create a session if necessary and bind to it, then run the WebCit
198 * transaction loop. Afterwards, we unbind from the session. When this
199 * function returns, the worker thread is then free to handle another
202 void context_loop(int sock)
204 struct httprequest *req = NULL;
205 struct httprequest *last = NULL;
206 struct httprequest *hptr;
207 char buf[256], hold[256];
208 int desired_session = 0;
210 struct wcsession *TheSession, *sptr;
212 fprintf(stderr, "Reading request from socket %d\n", sock);
215 * Find out what it is that the web browser is asking for
218 req_gets(sock, buf, hold);
219 if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
220 cookie_to_stuff(&buf[15], &desired_session,
225 hptr = (struct httprequest *)
226 malloc(sizeof(struct httprequest));
234 strcpy(hptr->line, buf);
236 } while (strlen(buf) > 0);
240 * If requesting a non-root page, there should already be a cookie
241 * set. If there isn't, the client browser has cookies turned off
242 * (or doesn't support them) and we have to barf & bail.
244 strcpy(buf, req->line);
245 if (!strncasecmp(buf, "GET ", 4)) strcpy(buf, &buf[4]);
246 else if (!strncasecmp(buf, "HEAD ", 5)) strcpy(buf, &buf[5]);
247 if (buf[1]==' ') buf[1]=0;
250 * While we're at it, gracefully handle requests for the
253 if (!strncasecmp(buf, "/robots.txt", 11)) {
254 strcpy(req->line, "GET /static/robots.txt HTTP/1.0");
257 /* Do the non-root-cookie check now. */
258 else if ( (strcmp(buf, "/")) && (got_cookie == 0)) {
259 strcpy(req->line, "GET /static/nocookies.html HTTP/1.0");
265 * See if there's an existing session open with the desired ID
268 if (desired_session != 0) {
269 pthread_mutex_lock(&SessionListMutex);
270 for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
271 if (sptr->wc_session == desired_session) {
275 pthread_mutex_unlock(&SessionListMutex);
279 * Create a new session if we have to
281 if (TheSession == NULL) {
282 printf("Creating a new session\n");
283 TheSession = (struct wcsession *)
284 malloc(sizeof(struct wcsession));
285 memset(TheSession, 0, sizeof(struct wcsession));
286 TheSession->wc_session = GenerateSessionID();
287 pthread_mutex_init(&TheSession->SessionMutex, NULL);
289 pthread_mutex_lock(&SessionListMutex);
290 TheSession->next = SessionList;
291 SessionList = TheSession;
292 pthread_mutex_unlock(&SessionListMutex);
298 * FIX ... check session integrity here before continuing
305 * Bind to the session and perform the transaction
307 pthread_mutex_lock(&TheSession->SessionMutex); /* bind */
308 pthread_setspecific(MyConKey, (void *)TheSession);
309 TheSession->http_sock = sock;
310 TheSession->lastreq = time(NULL); /* log */
311 fprintf(stderr, "Transaction: %s\n", req->line);
312 session_loop(req); /* perform the requested transaction */
313 pthread_mutex_unlock(&TheSession->SessionMutex); /* unbind */
315 /* Free the request buffer */
316 while (req != NULL) {
323 * Now our HTTP connection is done. Close the socket and exit this
324 * function, so the worker thread can handle a new HTTP connection.
326 printf(" Closing socket %d ... ret=%d\n", sock,
327 lingering_close(sock));