]> code.citadel.org Git - citadel.git/blobdiff - webcit/context_loop.c
* wildmat.c, braindamage.c: added
[citadel.git] / webcit / context_loop.c
index cbaf081f7006fda92a5b936824e9da2d5f0c893e..e128256dfa359c8b74118ffd2b870742e478ed9d 100644 (file)
@@ -34,6 +34,7 @@
 #include <errno.h>
 #include <stdarg.h>
 #include <pthread.h>
+#include <signal.h>
 #include "webcit.h"
 #include "webserver.h"
 
  */
 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;
 
 /* Only one thread may manipulate SessionList at a time... */
 pthread_mutex_t MasterCritter;
 
-int GenerateSessionID(void) {
-       return getpid();
+
+/*
+ * 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 gets0(int fd, char buf[]) {
+
+
+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();
+       }
+}
+
+
+
+
+
+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;
                        }
-               }
-       }
-
-/*
- * 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);
        }
+}
 
 /*
  * lingering_close() a`la Apache. see
  * http://www.apache.org/docs/misc/fin_wait_2.html for rationale
  */
 
-static int lingering_close(int fd) {
+static int lingering_close(int fd)
+{
        char buf[256];
        int i;
        fd_set set;
@@ -131,31 +216,30 @@ static int lingering_close(int fd) {
                        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);
+               } while (i == -1 && errno == EINTR);
 
                if (i <= 0)
                        break;
 
                i = read(fd, buf, sizeof buf);
-               } while (i != 0 && (i != -1 || errno == EINTR));
+       } while (i != 0 && (i != -1 || errno == EINTR));
 
        return close(fd);
-       }
-
-extern const char *defaulthost;
-extern const char *defaultport;
+}
 
 /*
  * This loop gets called once for every HTTP connection made to WebCit.
  */
-void *context_loop(int sock) {
+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;
@@ -166,13 +250,15 @@ void *context_loop(int sock) {
        int ContentLength;
        int CloseSession = 0;
 
-       if ((req = malloc((long)sizeof(char[256][256]))) == NULL) {
+       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);
+               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);
 
@@ -182,14 +268,17 @@ void *context_loop(int 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
@@ -197,23 +286,34 @@ void *context_loop(int sock) {
        TheSession = NULL;
        if (desired_session != 0) {
                pthread_mutex_lock(&MasterCritter);
-               for (sptr=SessionList; sptr!=NULL; sptr=sptr->next) {
+               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();
                pipe(TheSession->inpipe);
                pipe(TheSession->outpipe);
@@ -224,47 +324,65 @@ void *context_loop(int sock) {
                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);
+
                        /* 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, NULL);
+                              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 BACKGROUND=\"/image&name=background\" TEXT=\"#000000\" LINK=\"#004400\">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);
-                       }
-               /* Close the ends of the pipes that we're not using */
-               close(TheSession->inpipe[0]);
-               close(TheSession->outpipe[1]);
+               } else {
+                       /* Close the ends of the pipes that we're not using */
+                       close(TheSession->inpipe[0]);
+                       close(TheSession->outpipe[1]);
                }
-
+       }
        /* 
         * 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 > 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;
+               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.
@@ -279,58 +397,39 @@ void *context_loop(int sock) {
                        ContentLength = atoi(&buf[16]);
                if (!strcasecmp(buf, "X-WebCit-Session: close")) {
                        CloseSession = 1;
-                       }
-               } while (strlen(buf) > 0);
+               }
+       } while (strlen(buf) > 0);
 
        printf("   Reading %d bytes of content\n", ContentLength);
-       while(ContentLength--) {
+       while (ContentLength--) {
                read(TheSession->outpipe[0], buf, 1);
                write(sock, buf, 1);
-               }
+       }
 
        /*
         * If the last response included a "close session" directive,
         * remove the context now.
         */
        if (CloseSession) {
-               printf("Removing session.\n");
-               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]);
-               unlock_session(TheSession);
-               free(TheSession);
-       
-               pthread_mutex_unlock(&MasterCritter);
-               }
-       else {
-       end:
-               unlock_session(TheSession);
-               }
+               remove_session(TheSession, 1);
+       } else {
+             end:unlock_session(TheSession);
+       }
        free(req);
 
 
-        /*
-         * 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.
-         */
+       /*
+        * 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("   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;
+}