* up HTTP requests with the session they belong to, using HTTP cookies to
* keep track of things. If the HTTP request doesn't belong to any currently
* active session, a new session is spawned.
+ *
+ * $Id$
*/
+#include <ctype.h>
#include <stdlib.h>
+#ifdef HAVE_UNISTD_H
#include <unistd.h>
+#endif
#include <stdio.h>
+#ifdef HAVE_FCNTL_H
#include <fcntl.h>
+#endif
#include <signal.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
+#endif
+#ifdef HAVE_LIMITS_H
#include <limits.h>
+#endif
#include <netinet/in.h>
#include <netdb.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <pthread.h>
+#include <signal.h>
#include "webcit.h"
+#include "webserver.h"
/*
* We keep one of these around for each active session
*/
struct wc_session {
struct wc_session *next; /* Next session in list */
- int session_id; /* Session ID */
- int inpipe[2]; /* Data from webserver to session */
- int outpipe[2]; /* Data from session to webserver */
+ int session_id; /* Session ID */
+ pid_t webcit_pid; /* PID of the webcit process */
+ int inpipe[2]; /* Data from webserver to session */
+ int outpipe[2]; /* Data from session to webserver */
pthread_mutex_t critter; /* Critical section uses pipes */
- };
+ time_t lastreq; /* Timestamp of most recent http */
+};
struct wc_session *SessionList = NULL;
+extern const char *defaulthost;
+extern const char *defaultport;
-int GenerateSessionID() {
- return getpid();
+/* Only one thread may manipulate SessionList at a time... */
+pthread_mutex_t MasterCritter;
+
+
+/*
+ * Grab a lock on the session, so other threads don't try to access
+ * the pipes at the same time.
+ */
+static void lock_session(struct wc_session *session)
+{
+ printf("Locking session %d...\n", session->session_id);
+ pthread_mutex_lock(&session->critter);
+ printf(" ...got lock\n");
+}
+
+/*
+ * Let go of the lock.
+ */
+static void unlock_session(struct wc_session *session)
+{
+ printf("Unlocking.\n");
+ pthread_mutex_unlock(&session->critter);
+}
+
+/*
+ * Remove a session context from the list
+ */
+void remove_session(struct wc_session *TheSession, int do_lock)
+{
+ struct wc_session *sptr;
+
+ printf("Removing session.\n");
+ if (do_lock)
+ pthread_mutex_lock(&MasterCritter);
+
+ if (SessionList == TheSession) {
+ SessionList = SessionList->next;
+ } else {
+ for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
+ if (sptr->next == TheSession) {
+ sptr->next = TheSession->next;
+ }
+ }
+ }
+
+ close(TheSession->inpipe[1]);
+ close(TheSession->outpipe[0]);
+ if (do_lock)
+ unlock_session(TheSession);
+ free(TheSession);
+
+ pthread_mutex_unlock(&MasterCritter);
+}
+
+
+
+
+void do_housekeeping(void)
+{
+ struct wc_session *sptr;
+
+ pthread_mutex_lock(&MasterCritter);
+
+ /* Kill idle sessions */
+ for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
+ if ((time(NULL) - (sptr->lastreq)) > (time_t) WEBCIT_TIMEOUT) {
+ kill(sptr->webcit_pid, 15);
+ }
+ }
+
+ /* Remove dead sessions */
+ for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
+ if (kill(sptr->webcit_pid, 0)) {
+ remove_session(sptr, 0);
+ }
}
+ pthread_mutex_unlock(&MasterCritter);
+}
+
+
+/*
+ * Wake up occasionally and clean house
+ */
+void housekeeping_loop(void)
+{
+ while (1) {
+ sleep(HOUSEKEEPING);
+ do_housekeeping();
+ }
+}
+
+
-void gets0(int fd, char buf[]) {
+
+
+int GenerateSessionID(void)
+{
+ return getpid();
+}
+
+
+void gets0(int fd, char buf[])
+{
buf[0] = 0;
do {
- buf[strlen(buf)+1] = 0;
+ buf[strlen(buf) + 1] = 0;
read(fd, &buf[strlen(buf)], 1);
- } while (buf[strlen(buf)-1] >= 32);
- buf[strlen(buf)-1] = 0;
- }
+ } while (buf[strlen(buf) - 1] >= 32);
+ buf[strlen(buf) - 1] = 0;
+}
/*
* Collapse multiple cookies on one line
*/
-void req_gets(int sock, char *buf, char *hold) {
+void req_gets(int sock, char *buf, char *hold)
+{
int a;
- if (strlen(hold)==0) {
+ if (strlen(hold) == 0) {
client_gets(sock, buf);
- }
- else {
+ } else {
strcpy(buf, hold);
- }
+ }
strcpy(hold, "");
if (!strncasecmp(buf, "Cookie: ", 8)) {
- for (a=0; a<strlen(buf); ++a) if (buf[a]==';') {
- sprintf(hold, "Cookie: %s", &buf[a+1]);
- buf[a]=0;
- while (isspace(hold[8])) strcpy(&hold[8], &hold[9]);
- return;
+ for (a = 0; a < strlen(buf); ++a)
+ if (buf[a] == ';') {
+ sprintf(hold, "Cookie: %s", &buf[a + 1]);
+ buf[a] = 0;
+ while (isspace(hold[8]))
+ strcpy(&hold[8], &hold[9]);
+ return;
}
- }
}
+}
+
+/*
+ * lingering_close() a`la Apache. see
+ * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
+ */
+static int lingering_close(int fd)
+{
+ char buf[256];
+ int i;
+ fd_set set;
+ struct timeval tv, start;
+
+ gettimeofday(&start, NULL);
+ shutdown(fd, 1);
+ do {
+ do {
+ gettimeofday(&tv, NULL);
+ tv.tv_sec = SLEEPING - (tv.tv_sec - start.tv_sec);
+ tv.tv_usec = start.tv_usec - tv.tv_usec;
+ if (tv.tv_usec < 0) {
+ tv.tv_sec--;
+ tv.tv_usec += 1000000;
+ }
+ FD_ZERO(&set);
+ FD_SET(fd, &set);
+ i = select(fd + 1, &set, NULL, NULL, &tv);
+ } while (i == -1 && errno == EINTR);
+
+ if (i <= 0)
+ break;
+
+ i = read(fd, buf, sizeof buf);
+ } while (i != 0 && (i != -1 || errno == EINTR));
+
+ return close(fd);
+}
/*
* This loop gets called once for every HTTP connection made to WebCit.
*/
-void *context_loop(int *socknumptr) {
- char req[256][256];
+void *context_loop(int sock)
+{
+ char (*req)[256];
char buf[256], hold[256];
+ char browser_host[256];
+ char browser[256];
int num_lines = 0;
int a;
int f;
- int sock;
int desired_session = 0;
char str_session[256];
struct wc_session *sptr;
struct wc_session *TheSession;
int ContentLength;
+ int CloseSession = 0;
- sock = *socknumptr;
+ if ((req = malloc((long) sizeof(char[256][256]))) == NULL) {
+ sprintf(buf, "Can't malloc buffers; dropping connection.\n");
+ fprintf(stderr, "%s", buf);
+ write(sock, buf, strlen(buf));
+ close(sock);
+ pthread_exit(NULL);
+ }
+ bzero(req, sizeof(char[256][256])); /* clear it out */
+ strcpy(browser, "unknown");
printf("Reading request from socket %d\n", sock);
ContentLength = 0;
do {
req_gets(sock, buf, hold);
- if (!strncasecmp(buf, "Cookie: wc_session=", 19)) {
- desired_session = atoi(&buf[19]);
- }
+ if (!strncasecmp(buf, "Cookie: webcit=", 15)) {
+ cookie_to_stuff(&buf[15], &desired_session, NULL, NULL, NULL, NULL);
+ }
if (!strncasecmp(buf, "Content-length: ", 16)) {
ContentLength = atoi(&buf[16]);
- }
+ }
+ if (!strncasecmp(buf, "User-agent: ", 12)) {
+ strcpy(browser, &buf[12]);
+ }
strcpy(&req[num_lines++][0], buf);
- } while(strlen(buf)>0);
+ } while (strlen(buf) > 0);
/*
* See if there's an existing session open with the desired ID
*/
TheSession = NULL;
if (desired_session != 0) {
- for (sptr=SessionList; sptr!=NULL; sptr=sptr->next) {
+ pthread_mutex_lock(&MasterCritter);
+ for (sptr = SessionList; sptr != NULL; sptr = sptr->next) {
if (sptr->session_id == desired_session) {
TheSession = sptr;
- }
+ lock_session(TheSession);
}
}
-
+ pthread_mutex_unlock(&MasterCritter);
+ }
+ /*
+ * Before we trumpet to the universe that the session we're looking
+ * for actually exists, check first to make sure it's still there.
+ */
+ if (TheSession != NULL) {
+ if (kill(TheSession->webcit_pid, 0)) {
+ printf(" Session is *DEAD* !!\n");
+ remove_session(TheSession, 1);
+ TheSession = NULL;
+ }
+ }
/*
* Create a new session if we have to
*/
if (TheSession == NULL) {
printf("Creating a new session\n");
+ locate_host(browser_host, sock);
+ pthread_mutex_lock(&MasterCritter);
TheSession = (struct wc_session *)
- malloc(sizeof(struct wc_session));
+ malloc(sizeof(struct wc_session));
TheSession->session_id = GenerateSessionID();
- pthread_mutex_init(&TheSession->critter, NULL);
pipe(TheSession->inpipe);
pipe(TheSession->outpipe);
+ pthread_mutex_init(&TheSession->critter, NULL);
+ lock_session(TheSession);
TheSession->next = SessionList;
SessionList = TheSession;
+ pthread_mutex_unlock(&MasterCritter);
sprintf(str_session, "%d", TheSession->session_id);
f = fork();
- fflush(stdout); fflush(stdin);
- if (f==0) {
+ if (f > 0)
+ TheSession->webcit_pid = f;
+
+ fflush(stdout);
+ fflush(stdin);
+ if (f == 0) {
+
+ /* Hook stdio to the ends of the pipe we're using */
dup2(TheSession->inpipe[0], 0);
dup2(TheSession->outpipe[1], 1);
- execlp("./webcit", "webcit", str_session, NULL);
+
+ /* Close the ends of the pipes that we're not using */
+ close(TheSession->inpipe[1]);
+ close(TheSession->outpipe[0]);
+
+ /* Close the HTTP socket in this pid; don't need it */
+ close(sock);
+
+ /* Run the actual WebCit session */
+ execlp("./webcit", "webcit", str_session, defaulthost,
+ defaultport, browser_host, browser, NULL);
+
+ /* Simple page to display if exec fails */
printf("HTTP/1.0 404 WebCit Failure\n\n");
printf("Server: %s\n", SERVER);
+ printf("X-WebCit-Session: close\n");
printf("Content-type: text/html\n");
printf("Content-length: 76\n");
printf("\n");
- printf("<HTML><HEAD><TITLE>Error</TITLE></HEAD>\n");
- printf("<BODY>execlp() failed</BODY></HTML>\n");
+ printf("<HTML><HEAD><TITLE>Error</TITLE></HEAD><BODY>\n");
+ printf("execlp() failed: %s</BODY></HTML>\n", strerror(errno));
exit(0);
- }
+ } else {
+ /* Close the ends of the pipes that we're not using */
+ close(TheSession->inpipe[0]);
+ close(TheSession->outpipe[1]);
}
-
- /*
- * Grab a lock on the session, so other threads don't try to access
- * the pipes at the same time.
- */
- printf("Locking...\n");
- pthread_mutex_lock(&TheSession->critter);
-
+ }
/*
* Send the request to the appropriate session...
*/
+ TheSession->lastreq = time(NULL);
printf(" Writing %d lines of command\n", num_lines);
printf("%s\n", &req[0][0]);
- for (a=0; a<num_lines; ++a) {
+ for (a = 0; a < num_lines; ++a) {
write(TheSession->inpipe[1], &req[a][0], strlen(&req[a][0]));
write(TheSession->inpipe[1], "\n", 1);
- }
+ }
printf(" Writing %d bytes of content\n", ContentLength);
- while (ContentLength--) {
- read(sock, buf, 1);
- write(TheSession->inpipe[1], buf, 1);
- }
+ while (ContentLength > 0) {
+ a = ContentLength;
+ if (a > sizeof buf)
+ a = sizeof buf;
+ if (!client_read(sock, buf, a))
+ goto end;
+ if (write(TheSession->inpipe[1], buf, a) != a)
+ goto end;
+ ContentLength -= a;
+ }
/*
* ...and get the response.
write(sock, "\n", 1);
if (!strncasecmp(buf, "Content-length: ", 16))
ContentLength = atoi(&buf[16]);
- } while (strlen(buf) > 0);
+ if (!strcasecmp(buf, "X-WebCit-Session: close")) {
+ CloseSession = 1;
+ }
+ } while (strlen(buf) > 0);
- printf(" Reading %d bytes of content\n");
- while(ContentLength--) {
+ printf(" Reading %d bytes of content\n", ContentLength);
+ while (ContentLength--) {
read(TheSession->outpipe[0], buf, 1);
write(sock, buf, 1);
- }
+ }
/*
- * Now our HTTP connection is done. It would be relatively easy
- * to support HTTP/1.1 "persistent" connections by looping back to
- * the top of this function. For now, we'll just close.
+ * If the last response included a "close session" directive,
+ * remove the context now.
*/
- printf(" Closing socket\n");
- close(sock);
+ if (CloseSession) {
+ remove_session(TheSession, 1);
+ } else {
+ end:unlock_session(TheSession);
+ }
+ free(req);
+
/*
- * Let go of the lock
+ * Now our HTTP connection is done. It would be relatively easy
+ * to support HTTP/1.1 "persistent" connections by looping back to
+ * the top of this function. For now, we'll just close.
*/
- printf("Unlocking.\n");
- pthread_mutex_unlock(&TheSession->critter);
+ printf(" Closing socket %d ... ret=%d\n", sock,
+ lingering_close(sock));
/*
* The thread handling this HTTP connection is now finished.
+ * Instead of calling pthread_exit(), just return. It does the same
+ * thing, and supresses a compiler warning.
*/
- pthread_exit(NULL);
- }
+ return NULL;
+}
projects / citadel.git / blobdiff