* added message subject to all those tiny messages
[citadel.git] / citadel / sysdep.c
index 87d25681c3a940f87ea3b7fdff3ae84ca5625d8d..f4e20d72ebb3c6bda71acff9ecad6fce5d95f1e9 100644 (file)
@@ -1,7 +1,7 @@
 /*
  * $Id$
  *
- * Citadel/UX "system dependent" stuff.
+ * Citadel "system dependent" stuff.
  * See copyright.txt for copyright information.
  *
  * Here's where we (hopefully) have most parts of the Citadel server that
  *
  */
 
-#ifdef DLL_EXPORT
-#define IN_LIBCIT
-#endif
-
 #include "sysdep.h"
 #include <stdlib.h>
 #include <unistd.h>
 #endif
 
 #include <limits.h>
+#include <sys/resource.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
+#include <arpa/inet.h>
 #include <netdb.h>
 #include <sys/un.h>
 #include <string.h>
@@ -63,6 +62,7 @@
 #include "housekeeping.h"
 #include "tools.h"
 #include "serv_crypto.h"
+#include "serv_fulltext.h"
 
 #ifdef HAVE_SYS_SELECT_H
 #include <sys/select.h>
@@ -91,112 +91,75 @@ pthread_key_t MyConKey;                            /* TSD key for MyContext() */
 int verbosity = DEFAULT_VERBOSITY;             /* Logging level */
 
 struct CitContext masterCC;
-int rescan[2];                                 /* The Rescan Pipe */
 time_t last_purge = 0;                         /* Last dead session purge */
 static int num_threads = 0;                    /* Current number of threads */
 int num_sessions = 0;                          /* Current number of sessions */
+pthread_t indexer_thread_tid;
+pthread_t checkpoint_thread_tid;
 
-fd_set masterfds;                              /* Master sockets etc. */
-int masterhighest;
-
-pthread_t initial_thread;              /* tid for main() thread */
-
-int syslog_facility = (-1);
-
+int syslog_facility = LOG_DAEMON;
+int enable_syslog = 0;
+extern int running_as_daemon;
 
 /*
  * lprintf()  ...   Write logging information
- * 
- * Note: the variable "buf" below needs to be large enough to handle any
- * log data sent through this function.  BE CAREFUL!
  */
 void lprintf(enum LogLevel loglevel, const char *format, ...) {   
-        va_list arg_ptr;
-       char buf[SIZ];
-        va_start(arg_ptr, format);   
-        vsnprintf(buf, sizeof(buf), format, arg_ptr);   
-        va_end(arg_ptr);   
-
-       if (syslog_facility >= 0) {
-               if (loglevel <= verbosity) {
-                       /* Hackery -IO */
-                       if (CC && CC->cs_pid) {
-                               memmove(buf + 6, buf, sizeof(buf) - 6);
-                               snprintf(buf, 6, "[%3d]", CC->cs_pid);
-                               buf[5] = ' ';
-                       }
-                       syslog(loglevel, buf);
-               }
+       va_list arg_ptr;
+
+       if (enable_syslog) {
+               va_start(arg_ptr, format);
+                       vsyslog((syslog_facility | loglevel), format, arg_ptr);
+               va_end(arg_ptr);
        }
-       else if (loglevel <= verbosity) { 
+
+       /* stderr output code */
+       if (enable_syslog || running_as_daemon) return;
+
+       /* if we run in forground and syslog is disabled, log to terminal */
+       if (loglevel <= verbosity) { 
                struct timeval tv;
-               struct tm *tim;
+               struct tm tim;
                time_t unixtime;
 
                gettimeofday(&tv, NULL);
                /* Promote to time_t; types differ on some OSes (like darwin) */
                unixtime = tv.tv_sec;
-               tim = localtime(&unixtime);
-               /*
-                * Log provides millisecond accuracy.  If you need
-                * microsecond accuracy and your OS supports it, change
-                * %03ld to %06ld and remove " / 1000" after tv.tv_usec.
-                */
-               if (CC && CC->cs_pid) {
-#if 0
-                       /* Millisecond display */
+               localtime_r(&unixtime, &tim);
+               if (CC->cs_pid != 0) {
                        fprintf(stderr,
-                               "%04d/%02d/%02d %2d:%02d:%02d.%03ld [%3d] %s",
-                               tim->tm_year + 1900, tim->tm_mon + 1,
-                               tim->tm_mday, tim->tm_hour, tim->tm_min,
-                               tim->tm_sec, (long)tv.tv_usec / 1000,
-                               CC->cs_pid, buf);
-#endif
-                       /* Microsecond display */
-                       fprintf(stderr,
-                               "%04d/%02d/%02d %2d:%02d:%02d.%06ld [%3d] %s",
-                               tim->tm_year + 1900, tim->tm_mon + 1,
-                               tim->tm_mday, tim->tm_hour, tim->tm_min,
-                               tim->tm_sec, (long)tv.tv_usec,
-                               CC->cs_pid, buf);
+                               "%04d/%02d/%02d %2d:%02d:%02d.%06ld [%3d] ",
+                               tim.tm_year + 1900, tim.tm_mon + 1,
+                               tim.tm_mday, tim.tm_hour, tim.tm_min,
+                               tim.tm_sec, (long)tv.tv_usec,
+                               CC->cs_pid);
                } else {
-#if 0
-                       /* Millisecond display */
-                       fprintf(stderr,
-                               "%04d/%02d/%02d %2d:%02d:%02d.%03ld %s",
-                               tim->tm_year + 1900, tim->tm_mon + 1,
-                               tim->tm_mday, tim->tm_hour, tim->tm_min,
-                               tim->tm_sec, (long)tv.tv_usec / 1000, buf);
-#endif
-                       /* Microsecond display */
                        fprintf(stderr,
-                               "%04d/%02d/%02d %2d:%02d:%02d.%06ld %s",
-                               tim->tm_year + 1900, tim->tm_mon + 1,
-                               tim->tm_mday, tim->tm_hour, tim->tm_min,
-                               tim->tm_sec, (long)tv.tv_usec, buf);
+                               "%04d/%02d/%02d %2d:%02d:%02d.%06ld ",
+                               tim.tm_year + 1900, tim.tm_mon + 1,
+                               tim.tm_mday, tim.tm_hour, tim.tm_min,
+                               tim.tm_sec, (long)tv.tv_usec);
                }
+               va_start(arg_ptr, format);   
+                       vfprintf(stderr, format, arg_ptr);   
+               va_end(arg_ptr);   
                fflush(stderr);
        }
-
-       PerformLogHooks(loglevel, buf);
 }   
 
 
 
 /*
- * We used to use master_cleanup() as a signal handler to shut down the server.
- * however, master_cleanup() and the functions it calls do some things that
- * aren't such a good idea to do from a signal handler: acquiring mutexes,
- * playing with signal masks on BSDI systems, etc. so instead we install the
- * following signal handler to set a global variable to inform the main loop
- * that it's time to call master_cleanup() and exit.
+ * Signal handler to shut down the server.
  */
 
 volatile int time_to_die = 0;
+volatile int shutdown_and_halt = 0;
 
 static RETSIGTYPE signal_cleanup(int signum) {
+       lprintf(CTDL_DEBUG, "Caught signal %d; shutting down.\n", signum);
        time_to_die = 1;
+       master_cleanup(signum);
 }
 
 
@@ -204,19 +167,28 @@ static RETSIGTYPE signal_cleanup(int signum) {
  * Some initialization stuff...
  */
 void init_sysdep(void) {
-       int a;
-
-       /* Enable core dumps */
-       struct rlimit lim = { RLIM_INFINITY, RLIM_INFINITY };
-       setrlimit(RLIMIT_CORE, &lim);
+       int i;
+       sigset_t set;
+
+       /* Avoid vulnerabilities related to FD_SETSIZE if we can. */
+#ifdef FD_SETSIZE
+#ifdef RLIMIT_NOFILE
+       struct rlimit rl;
+       getrlimit(RLIMIT_NOFILE, &rl);
+       rl.rlim_cur = FD_SETSIZE;
+       rl.rlim_max = FD_SETSIZE;
+       setrlimit(RLIMIT_NOFILE, &rl);
+#endif
+#endif
 
+       /* If we've got OpenSSL, we're going to use it. */
 #ifdef HAVE_OPENSSL
        init_ssl();
 #endif
 
        /* Set up a bunch of semaphores to be used for critical sections */
-       for (a=0; a<MAX_SEMAPHORES; ++a) {
-               pthread_mutex_init(&Critters[a], NULL);
+       for (i=0; i<MAX_SEMAPHORES; ++i) {
+               pthread_mutex_init(&Critters[i], NULL);
        }
 
        /*
@@ -226,17 +198,31 @@ void init_sysdep(void) {
         * session to which the calling thread is currently bound.
         */
        if (pthread_key_create(&MyConKey, NULL) != 0) {
-               lprintf(CTDL_CRIT, "Can't create TSD key!!  %s\n", strerror(errno));
+               lprintf(CTDL_CRIT, "Can't create TSD key: %s\n",
+                       strerror(errno));
        }
 
        /*
         * The action for unexpected signals and exceptions should be to
         * call signal_cleanup() to gracefully shut down the server.
         */
+       sigemptyset(&set);
+       sigaddset(&set, SIGINT);
+       sigaddset(&set, SIGQUIT);
+       sigaddset(&set, SIGHUP);
+       sigaddset(&set, SIGTERM);
+       // sigaddset(&set, SIGSEGV);    commented out because
+       // sigaddset(&set, SIGILL);     we want core dumps
+       // sigaddset(&set, SIGBUS);
+       sigprocmask(SIG_UNBLOCK, &set, NULL);
+
        signal(SIGINT, signal_cleanup);
        signal(SIGQUIT, signal_cleanup);
        signal(SIGHUP, signal_cleanup);
        signal(SIGTERM, signal_cleanup);
+       // signal(SIGSEGV, signal_cleanup);     commented out because
+       // signal(SIGILL, signal_cleanup);      we want core dumps
+       // signal(SIGBUS, signal_cleanup);
 
        /*
         * Do not shut down the server on broken pipe signals, otherwise the
@@ -262,6 +248,7 @@ void begin_critical_section(int which_one)
 #ifdef DEBUG_MEMORY_LEAKS
                && (which_one != S_DEBUGMEMLEAKS)
 #endif
+               && (which_one != S_RPLIST)
        ) {
                cdb_check_handles();
        }
@@ -283,7 +270,7 @@ void end_critical_section(int which_one)
  * a TCP port.  The server shuts down if the bind fails.
  *
  */
-int ig_tcp_server(int port_number, int queue_len)
+int ig_tcp_server(char *ip_addr, int port_number, int queue_len, char **errormessage)
 {
        struct sockaddr_in sin;
        int s, i;
@@ -294,14 +281,26 @@ int ig_tcp_server(int port_number, int queue_len)
 
        memset(&sin, 0, sizeof(sin));
        sin.sin_family = AF_INET;
-       sin.sin_addr.s_addr = INADDR_ANY;
        sin.sin_port = htons((u_short)port_number);
+       if (ip_addr == NULL) {
+               sin.sin_addr.s_addr = INADDR_ANY;
+       }
+       else {
+               sin.sin_addr.s_addr = inet_addr(ip_addr);
+       }
+                                                                               
+       if (sin.sin_addr.s_addr == INADDR_NONE) {
+               sin.sin_addr.s_addr = INADDR_ANY;
+       }
 
        s = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
 
        if (s < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't create a socket: %s\n",
-                       strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                                "citserver: Can't create a socket: %s",
+                                strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                return(-1);
        }
 
@@ -309,14 +308,32 @@ int ig_tcp_server(int port_number, int queue_len)
        setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i));
 
        if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't bind: %s\n",
-                       strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                                "citserver: Can't bind: %s",
+                                strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
+               close(s);
+               return(-1);
+       }
+
+       /* set to nonblock - we need this for some obscure situations */
+       if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                                "citserver: Can't set socket to non-blocking: %s",
+                                strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                close(s);
                return(-1);
        }
 
        if (listen(s, actual_queue_len) < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't listen: %s\n", strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                                "citserver: Can't listen: %s",
+                                strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                close(s);
                return(-1);
        }
@@ -329,7 +346,7 @@ int ig_tcp_server(int port_number, int queue_len)
 /*
  * Create a Unix domain socket and listen on it
  */
-int ig_uds_server(char *sockpath, int queue_len)
+int ig_uds_server(char *sockpath, int queue_len, char **errormessage)
 {
        struct sockaddr_un addr;
        int s;
@@ -341,8 +358,10 @@ int ig_uds_server(char *sockpath, int queue_len)
 
        i = unlink(sockpath);
        if (i != 0) if (errno != ENOENT) {
-               lprintf(CTDL_EMERG, "citserver: can't unlink %s: %s\n",
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, "citserver: can't unlink %s: %s",
                        sockpath, strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                return(-1);
        }
 
@@ -352,19 +371,40 @@ int ig_uds_server(char *sockpath, int queue_len)
 
        s = socket(AF_UNIX, SOCK_STREAM, 0);
        if (s < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't create a socket: %s\n",
-                       strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                        "citserver: Can't create a socket: %s",
+                        strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                return(-1);
        }
 
        if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't bind: %s\n",
-                       strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                        "citserver: Can't bind: %s",
+                        strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
+               return(-1);
+       }
+
+       /* set to nonblock - we need this for some obscure situations */
+       if (fcntl(s, F_SETFL, O_NONBLOCK) < 0) {
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                        "citserver: Can't set socket to non-blocking: %s",
+                        strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
+               close(s);
                return(-1);
        }
 
        if (listen(s, actual_queue_len) < 0) {
-               lprintf(CTDL_EMERG, "citserver: Can't listen: %s\n", strerror(errno));
+               *errormessage = (char*) malloc(SIZ + 1);
+               snprintf(*errormessage, SIZ, 
+                        "citserver: Can't listen: %s",
+                        strerror(errno));
+               lprintf(CTDL_EMERG, "%s\n", *errormessage);
                return(-1);
        }
 
@@ -379,12 +419,14 @@ int ig_uds_server(char *sockpath, int queue_len)
  * called this function.  If there's no such binding (for example, if it's
  * called by the housekeeper thread) then a generic 'master' CC is returned.
  *
- * It's inlined because it's used *VERY* frequently.
+ * This function is used *VERY* frequently and must be kept small.
  */
-INLINE struct CitContext *MyContext(void) {
-       return ((pthread_getspecific(MyConKey) == NULL)
-               ? &masterCC
-               : (struct CitContext *) pthread_getspecific(MyConKey)
+struct CitContext *MyContext(void) {
+
+       register struct CitContext *c;
+
+       return ((c = (struct CitContext *) pthread_getspecific(MyConKey),
+               c == NULL) ? &masterCC : c
        );
 }
 
@@ -393,11 +435,11 @@ INLINE struct CitContext *MyContext(void) {
  * Initialize a new context and place it in the list.  The session number
  * used to be the PID (which is why it's called cs_pid), but that was when we
  * had one process per session.  Now we just assign them sequentially, starting
- * at 1 (don't change it to 0 because masterCC uses 0) and re-using them when
- * sessions terminate.
+ * at 1 (don't change it to 0 because masterCC uses 0).
  */
 struct CitContext *CreateNewContext(void) {
-       struct CitContext *me, *ptr;
+       struct CitContext *me;
+       static int next_pid = 0;
 
        me = (struct CitContext *) malloc(sizeof(struct CitContext));
        if (me == NULL) {
@@ -412,52 +454,59 @@ struct CitContext *CreateNewContext(void) {
         */
        me->state = CON_EXECUTING;
 
-
        /*
         * Generate a unique session number and insert this context into
         * the list.
         */
        begin_critical_section(S_SESSION_TABLE);
-
-       if (ContextList == NULL) {
-               ContextList = me;
-               me->cs_pid = 1;
-               me->next = NULL;
-       }
-
-       else if (ContextList->cs_pid > 1) {
-               me->next = ContextList;
-               ContextList = me;
-               me->cs_pid = 1;
+       me->cs_pid = ++next_pid;
+       me->prev = NULL;
+       me->next = ContextList;
+       ContextList = me;
+       if (me->next != NULL) {
+               me->next->prev = me;
        }
-
-       else {
-               for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
-                       if (ptr->next == NULL) {
-                               ptr->next = me;
-                               me->cs_pid = ptr->cs_pid + 1;
-                               me->next = NULL;
-                               goto DONE;
-                       }
-                       else if (ptr->next->cs_pid > (ptr->cs_pid+1)) {
-                               me->next = ptr->next;
-                               ptr->next = me;
-                               me->cs_pid = ptr->cs_pid + 1;
-                               goto DONE;
-                       }
-               }
-       }
-
-DONE:  ++num_sessions;
+       ++num_sessions;
        end_critical_section(S_SESSION_TABLE);
        return(me);
 }
 
 
 /*
- * buffer_output() ... tell client_write to buffer all output until
- *                     instructed to dump it all out later
+ * The following functions implement output buffering. If the kernel supplies
+ * native TCP buffering (Linux & *BSD), use that; otherwise, emulate it with
+ * user-space buffering.
  */
+#ifdef TCP_CORK
+#      define HAVE_TCP_BUFFERING
+#else
+#      ifdef TCP_NOPUSH
+#              define HAVE_TCP_BUFFERING
+#              define TCP_CORK TCP_NOPUSH
+#      endif
+#endif
+
+
+#ifdef HAVE_TCP_BUFFERING
+static unsigned on = 1, off = 0;
+void buffer_output(void) {
+       struct CitContext *ctx = MyContext();
+       setsockopt(ctx->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
+       ctx->buffering = 1;
+}
+
+void unbuffer_output(void) {
+       struct CitContext *ctx = MyContext();
+       setsockopt(ctx->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
+       ctx->buffering = 0;
+}
+
+void flush_output(void) {
+       struct CitContext *ctx = MyContext();
+       setsockopt(ctx->client_socket, IPPROTO_TCP, TCP_CORK, &off, 4);
+       setsockopt(ctx->client_socket, IPPROTO_TCP, TCP_CORK, &on, 4);
+}
+#else
 void buffer_output(void) {
        if (CC->buffering == 0) {
                CC->buffering = 1;
@@ -466,18 +515,24 @@ void buffer_output(void) {
        }
 }
 
-/*
- * unbuffer_output()  ...  dump out all that output we've been buffering.
- */
+void flush_output(void) {
+       if (CC->buffering == 1) {
+               client_write(CC->output_buffer, CC->buffer_len);
+               CC->buffer_len = 0;
+       }
+}
+
 void unbuffer_output(void) {
        if (CC->buffering == 1) {
                CC->buffering = 0;
+               /* We don't call flush_output because we can't. */
                client_write(CC->output_buffer, CC->buffer_len);
+               CC->buffer_len = 0;
                free(CC->output_buffer);
                CC->output_buffer = NULL;
-               CC->buffer_len = 0;
        }
 }
+#endif
 
 
 
@@ -488,21 +543,23 @@ void client_write(char *buf, int nbytes)
 {
        int bytes_written = 0;
        int retval;
-       int sock;
+#ifndef HAVE_TCP_BUFFERING
        int old_buffer_len = 0;
+#endif
 
-       if (CC->redirect_fp != NULL) {
-               fwrite(buf, nbytes, 1, CC->redirect_fp);
+       if (CC->redirect_buffer != NULL) {
+               if ((CC->redirect_len + nbytes + 2) >= CC->redirect_alloc) {
+                       CC->redirect_alloc = (CC->redirect_alloc * 2) + nbytes;
+                       CC->redirect_buffer = realloc(CC->redirect_buffer,
+                                               CC->redirect_alloc);
+               }
+               memcpy(&CC->redirect_buffer[CC->redirect_len], buf, nbytes);
+               CC->redirect_len += nbytes;
+               CC->redirect_buffer[CC->redirect_len] = 0;
                return;
        }
 
-       if (CC->redirect_sock > 0) {
-               sock = CC->redirect_sock;       /* and continue below... */
-       }
-       else {
-               sock = CC->client_socket;
-       }
-
+#ifndef HAVE_TCP_BUFFERING
        /* If we're buffering for later, do that now. */
        if (CC->buffering) {
                old_buffer_len = CC->buffer_len;
@@ -511,6 +568,7 @@ void client_write(char *buf, int nbytes)
                memcpy(&CC->output_buffer[old_buffer_len], buf, nbytes);
                return;
        }
+#endif
 
        /* Ok, at this point we're not buffering.  Go ahead and write. */
 
@@ -522,12 +580,14 @@ void client_write(char *buf, int nbytes)
 #endif
 
        while (bytes_written < nbytes) {
-               retval = write(sock, &buf[bytes_written],
+               retval = write(CC->client_socket, &buf[bytes_written],
                        nbytes - bytes_written);
                if (retval < 1) {
-                       lprintf(CTDL_ERR, "client_write() failed: %s\n",
-                               strerror(errno));
-                       if (sock == CC->client_socket) CC->kill_me = 1;
+                       lprintf(CTDL_ERR,
+                               "client_write(%d bytes) failed: %s (%d)\n",
+                               nbytes - bytes_written,
+                               strerror(errno), errno);
+                       CC->kill_me = 1;
                        return;
                }
                bytes_written = bytes_written + retval;
@@ -537,15 +597,15 @@ void client_write(char *buf, int nbytes)
 
 /*
  * cprintf()  ...   Send formatted printable data to the client.   It is
- *                  implemented in terms of client_write() but remains in
- *                  sysdep.c in case we port to somewhere without va_args...
+ *               implemented in terms of client_write() but remains in
+ *               sysdep.c in case we port to somewhere without va_args...
  */
 void cprintf(const char *format, ...) {   
-        va_list arg_ptr;   
-        char buf[SIZ];   
+       va_list arg_ptr;   
+       char buf[1024];   
    
-        va_start(arg_ptr, format);   
-        if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
+       va_start(arg_ptr, format);   
+       if (vsnprintf(buf, sizeof buf, format, arg_ptr) == -1)
                buf[sizeof buf - 2] = '\n';
        client_write(buf, strlen(buf)); 
        va_end(arg_ptr);
@@ -588,8 +648,7 @@ int client_read_to(char *buf, int bytes, int timeout)
 
                rlen = read(CC->client_socket, &buf[len], bytes-len);
                if (rlen<1) {
-                       lprintf(CTDL_ERR, "client_read() failed: %s\n",
-                               strerror(errno));
+                       /* The socket has been disconnected! */
                        CC->kill_me = 1;
                        return(-1);
                }
@@ -610,11 +669,11 @@ INLINE int client_read(char *buf, int bytes)
 
 
 /*
- * client_gets()   ...   Get a LF-terminated line of text from the client.
+ * client_getln()   ...   Get a LF-terminated line of text from the client.
  * (This is implemented in terms of client_read() and could be
  * justifiably moved out of sysdep.c)
  */
-int client_gets(char *buf)
+int client_getln(char *buf, int bufsize)
 {
        int i, retval;
 
@@ -622,22 +681,23 @@ int client_gets(char *buf)
         */
        for (i = 0;;i++) {
                retval = client_read(&buf[i], 1);
-               if (retval != 1 || buf[i] == '\n' || i == (SIZ-1))
+               if (retval != 1 || buf[i] == '\n' || i == (bufsize-1))
                        break;
        }
 
        /* If we got a long line, discard characters until the newline.
         */
-       if (i == (SIZ-1))
+       if (i == (bufsize-1))
                while (buf[i] != '\n' && retval == 1)
                        retval = client_read(&buf[i], 1);
 
-       /* Strip the trailing newline and any trailing nonprintables (cr's)
+       /* Strip the trailing LF, and the trailing CR if present.
         */
        buf[i] = 0;
-       while ((strlen(buf)>0)&&(!isprint(buf[strlen(buf)-1])))
+       while ( (strlen(buf) > 0) && ((buf[strlen(buf)-1]==10) || (buf[strlen(buf)-1] == 13)) ) {
                buf[strlen(buf)-1] = 0;
-       if (retval < 0) strcpy(buf, "000");
+       }
+       if (retval < 0) safestrncpy(buf, "000", bufsize);
        return(retval);
 }
 
@@ -694,18 +754,15 @@ void kill_session(int session_to_kill) {
 
 
 /*
- * Start running as a daemon.  Only close stdio if do_close_stdio is set.
+ * Start running as a daemon.
  */
-void start_daemon(int do_close_stdio) {
-       if (do_close_stdio) {
-               /* close(0); */
-               close(1);
-               close(2);
-       }
+void start_daemon(int unused) {
+       close(0); close(1); close(2);
+       if (fork()) exit(0);
+       setsid();
        signal(SIGHUP,SIG_IGN);
        signal(SIGINT,SIG_IGN);
        signal(SIGQUIT,SIG_IGN);
-       if (fork()!=0) exit(0);
 }
 
 
@@ -756,11 +813,15 @@ void create_worker(void) {
                return;
        }
 
-       /* we seem to need something bigger than FreeBSD's default 64k stack */
-
-       if ((ret = pthread_attr_setstacksize(&attr, 128 * 1024))) {
-               lprintf(CTDL_EMERG, "pthread_attr_setstacksize: %s\n", strerror(ret));
+       /* Our per-thread stacks need to be bigger than the default size,
+        * otherwise the MIME parser crashes on FreeBSD, and the IMAP service
+        * crashes on 64-bit Linux.
+        */
+       if ((ret = pthread_attr_setstacksize(&attr, THREADSTACKSIZE))) {
+               lprintf(CTDL_EMERG, "pthread_attr_setstacksize: %s\n",
+                       strerror(ret));
                time_to_die = -1;
+               pthread_attr_destroy(&attr);
                return;
        }
 
@@ -773,6 +834,45 @@ void create_worker(void) {
 
        n->next = worker_list;
        worker_list = n;
+       pthread_attr_destroy(&attr);
+}
+
+
+/*
+ * Create the indexer thread and begin its operation.
+ * Then create the checkpoint thread and begin its operation.
+ */
+void create_maintenance_threads(void) {
+       int ret;
+       pthread_attr_t attr;
+
+       if ((ret = pthread_attr_init(&attr))) {
+               lprintf(CTDL_EMERG, "pthread_attr_init: %s\n", strerror(ret));
+               time_to_die = -1;
+               return;
+       }
+
+       /* Our per-thread stacks need to be bigger than the default size,
+        * otherwise the MIME parser crashes on FreeBSD, and the IMAP service
+        * crashes on 64-bit Linux.
+        */
+       if ((ret = pthread_attr_setstacksize(&attr, THREADSTACKSIZE))) {
+               lprintf(CTDL_EMERG, "pthread_attr_setstacksize: %s\n",
+                       strerror(ret));
+               time_to_die = -1;
+               pthread_attr_destroy(&attr);
+               return;
+       }
+
+       if ((ret = pthread_create(&indexer_thread_tid, &attr, indexer_thread, NULL) != 0)) {
+               lprintf(CTDL_ALERT, "Can't create thread: %s\n", strerror(ret));
+       }
+
+       if ((ret = pthread_create(&checkpoint_thread_tid, &attr, checkpoint_thread, NULL) != 0)) {
+               lprintf(CTDL_ALERT, "Can't create thread: %s\n", strerror(ret));
+       }
+
+       pthread_attr_destroy(&attr);
 }
 
 
@@ -781,39 +881,62 @@ void create_worker(void) {
  * Purge all sessions which have the 'kill_me' flag set.
  * This function has code to prevent it from running more than once every
  * few seconds, because running it after every single unbind would waste a lot
- * of CPU time and keep the context list locked too much.
+ * of CPU time and keep the context list locked too much.  To force it to run
+ * anyway, set "force" to nonzero.
+ *
  *
- * After that's done, we raise or lower the size of the worker thread pool
+ * After that's done, we raise the size of the worker thread pool
  * if such an action is appropriate.
  */
-void dead_session_purge(void) {
-       struct CitContext *ptr, *rem;
+void dead_session_purge(int force) {
+       struct CitContext *ptr;         /* general-purpose utility pointer */
+       struct CitContext *rem = NULL;  /* list of sessions to be destroyed */
 
-       if ( (time(NULL) - last_purge) < 5 ) return;    /* Too soon, go away */
+       if (force == 0) {
+               if ( (time(NULL) - last_purge) < 5 ) {
+                       return; /* Too soon, go away */
+               }
+       }
        time(&last_purge);
 
-       do {
-               rem = NULL;
-               begin_critical_section(S_SESSION_TABLE);
-               for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
-                       if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
-                               rem = ptr;
+       begin_critical_section(S_SESSION_TABLE);
+       for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
+               if ( (ptr->state == CON_IDLE) && (ptr->kill_me) ) {
+
+                       /* Remove the session from the active list */
+                       if (ptr->prev) {
+                               ptr->prev->next = ptr->next;
                        }
-               }
-               end_critical_section(S_SESSION_TABLE);
+                       else {
+                               ContextList = ptr->next;
+                       }
+                       if (ptr->next) {
+                               ptr->next->prev = ptr->prev;
+                       }
+
+                       --num_sessions;
+
+                       /* And put it on our to-be-destroyed list */
+                       ptr->next = rem;
+                       rem = ptr;
 
-               /* RemoveContext() enters its own S_SESSION_TABLE critical
-                * section, so we have to do it like this.
-                */     
-               if (rem != NULL) {
-                       lprintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
-                       RemoveContext(rem);
                }
+       }
+       end_critical_section(S_SESSION_TABLE);
 
-       } while (rem != NULL);
+       /* Now that we no longer have the session list locked, we can take
+        * our time and destroy any sessions on the to-be-killed list, which
+        * is allocated privately on this thread's stack.
+        */
+       while (rem != NULL) {
+               lprintf(CTDL_DEBUG, "Purging session %d\n", rem->cs_pid);
+               RemoveContext(rem);
+               ptr = rem;
+               rem = rem->next;
+               free(ptr);
+       }
 
        /* Raise the size of the worker thread pool if necessary. */
-
        if ( (num_sessions > num_threads)
           && (num_threads < config.c_max_workers) ) {
                begin_critical_section(S_WORKER_LIST);
@@ -826,22 +949,6 @@ void dead_session_purge(void) {
 
 
 
-/*
- * Redirect a session's output to a file or socket.
- * This function may be called with a file handle *or* a socket (but not
- * both).  Call with neither to return output to its normal client socket.
- */
-void CtdlRedirectOutput(FILE *fp, int sock) {
-
-       if (fp != NULL) CC->redirect_fp = fp;
-       else CC->redirect_fp = NULL;
-
-       if (sock > 0) CC->redirect_sock = sock;
-       else CC->redirect_sock = (-1);
-
-}
-
-
 /*
  * masterCC is the context we use when not attached to a session.  This
  * function initializes it.
@@ -854,37 +961,7 @@ void InitializeMasterCC(void) {
 
 
 
-/*
- * Set up a fd_set containing all the master sockets to which we
- * always listen.  It's computationally less expensive to just copy
- * this to a local fd_set when starting a new select() and then add
- * the client sockets than it is to initialize a new one and then
- * figure out what to put there.
- */
-void init_master_fdset(void) {
-       struct ServiceFunctionHook *serviceptr;
-       int m;
-
-       lprintf(CTDL_DEBUG, "Initializing master fdset\n");
-
-       FD_ZERO(&masterfds);
-       masterhighest = 0;
-
-       lprintf(CTDL_DEBUG, "Will listen on rescan pipe %d\n", rescan[0]);
-       FD_SET(rescan[0], &masterfds);
-       if (rescan[0] > masterhighest) masterhighest = rescan[0];
 
-       for (serviceptr = ServiceHookTable; serviceptr != NULL;
-           serviceptr = serviceptr->next ) {
-               m = serviceptr->msock;
-               lprintf(CTDL_DEBUG, "Will listen on master socket %d\n", m);
-               FD_SET(m, &masterfds);
-               if (m > masterhighest) {
-                       masterhighest = m;
-               }
-       }
-       lprintf(CTDL_DEBUG, "masterhighest = %d\n", masterhighest);
-}
 
 
 /*
@@ -901,18 +978,17 @@ INLINE void become_session(struct CitContext *which_con) {
  */    
 void *worker_thread(void *arg) {
        int i;
-       char junk;
        int highest;
-       /* This is synchronized below; it helps implement round robin mode */
-       static struct CitContext* next_session = NULL;
        struct CitContext *ptr;
        struct CitContext *bind_me = NULL;
        fd_set readfds;
-       int retval;
+       int retval = 0;
        struct CitContext *con= NULL;   /* Temporary context pointer */
        struct ServiceFunctionHook *serviceptr;
        int ssock;                      /* Descriptor for client socket */
        struct timeval tv;
+       int force_purge = 0;
+       int m;
 
        num_threads++;
 
@@ -920,26 +996,17 @@ void *worker_thread(void *arg) {
 
        while (!time_to_die) {
 
-               /* 
-                * A naive implementation would have all idle threads
-                * calling select() and then they'd all wake up at once
-                * (known in computer science as the "thundering herd"
-                * problem).  We solve this problem by putting the select()
-                * in a critical section, so only one thread has the
-                * opportunity to wake up.  If we wake up on a master
-                * socket, create a new session context; otherwise, just
-                * bind the thread to the context we want and go on our
-                * merry way.
-                */
-
                /* make doubly sure we're not holding any stale db handles
                 * which might cause a deadlock.
                 */
                cdb_check_handles();
+do_select:     force_purge = 0;
+               bind_me = NULL;         /* Which session shall we handle? */
+
+               /* Initialize the fdset. */
+               FD_ZERO(&readfds);
+               highest = 0;
 
-               begin_critical_section(S_I_WANNA_SELECT);
-SETUP_FD:      memcpy(&readfds, &masterfds, sizeof masterfds);
-               highest = masterhighest;
                begin_critical_section(S_SESSION_TABLE);
                for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
                        if (ptr->state == CON_IDLE) {
@@ -947,24 +1014,49 @@ SETUP_FD:        memcpy(&readfds, &masterfds, sizeof masterfds);
                                if (ptr->client_socket > highest)
                                        highest = ptr->client_socket;
                        }
+                       if ((bind_me == NULL) && (ptr->state == CON_READY)) {
+                               bind_me = ptr;
+                               ptr->state = CON_EXECUTING;
+                       }
                }
                end_critical_section(S_SESSION_TABLE);
 
-               tv.tv_sec = 1;          /* wake up every second if no input */
-               tv.tv_usec = 0;
+               if (bind_me) {
+                       goto SKIP_SELECT;
+               }
+
+               /* If we got this far, it means that there are no sessions
+                * which a previous thread marked for attention, so we go
+                * ahead and get ready to select().
+                */
+
+               /* First, add the various master sockets to the fdset. */
+               for (serviceptr = ServiceHookTable; serviceptr != NULL;
+               serviceptr = serviceptr->next ) {
+                       m = serviceptr->msock;
+                       FD_SET(m, &readfds);
+                       if (m > highest) {
+                               highest = m;
+                       }
+               }
 
-               do_select:
-               if (!time_to_die)
+               if (!time_to_die) {
+                       tv.tv_sec = 1;          /* wake up every second if no input */
+                       tv.tv_usec = 0;
                        retval = select(highest + 1, &readfds, NULL, NULL, &tv);
-               else {
-                       end_critical_section(S_I_WANNA_SELECT);
-                       break;
                }
 
+               if (time_to_die) return(NULL);
+
                /* Now figure out who made this select() unblock.
                 * First, check for an error or exit condition.
                 */
                if (retval < 0) {
+                       if (errno == EBADF) {
+                               lprintf(CTDL_NOTICE, "select() failed: (%s)\n",
+                                       strerror(errno));
+                               goto do_select;
+                       }
                        if (errno != EINTR) {
                                lprintf(CTDL_EMERG, "Exiting (%s)\n", strerror(errno));
                                time_to_die = 1;
@@ -980,27 +1072,34 @@ SETUP_FD:        memcpy(&readfds, &masterfds, sizeof masterfds);
 
                        if (FD_ISSET(serviceptr->msock, &readfds)) {
                                ssock = accept(serviceptr->msock, NULL, 0);
-                               if (ssock < 0) {
-                                       lprintf(CTDL_CRIT,
-                                               "citserver: accept(): %s\n",
-                                               strerror(errno));
-                               }
-                               else {
-                                       lprintf(CTDL_NOTICE,
+                               if (ssock >= 0) {
+                                       lprintf(CTDL_DEBUG,
                                                "New client socket %d\n",
                                                ssock);
 
+                                       /* The master socket is non-blocking but the client
+                                        * sockets need to be blocking, otherwise certain
+                                        * operations barf on FreeBSD.  Not a fatal error.
+                                        */
+                                       if (fcntl(ssock, F_SETFL, 0) < 0) {
+                                               lprintf(CTDL_EMERG,
+                                                       "citserver: Can't set socket to blocking: %s\n",
+                                                       strerror(errno));
+                                       }
+
                                        /* New context will be created already
-                                       * set up in the CON_EXECUTING state.
-                                       */
+                                        * set up in the CON_EXECUTING state.
+                                        */
                                        con = CreateNewContext();
 
-                                       /* Assign new socket number to it. */
+                                       /* Assign our new socket number to it. */
                                        con->client_socket = ssock;
                                        con->h_command_function =
                                                serviceptr->h_command_function;
+                                       con->h_async_function =
+                                               serviceptr->h_async_function;
 
-                                       /* Determine whether local socket */
+                                       /* Determine whether it's a local socket */
                                        if (serviceptr->sockpath != NULL)
                                                con->is_local_socket = 1;
        
@@ -1015,83 +1114,64 @@ SETUP_FD:       memcpy(&readfds, &masterfds, sizeof masterfds);
                                        serviceptr->h_greeting_function();
                                        become_session(NULL);
                                        con->state = CON_IDLE;
-                                       goto SETUP_FD;
+                                       goto do_select;
                                }
                        }
                }
 
-               if (time_to_die) {
-                       end_critical_section(S_I_WANNA_SELECT);
-                       break;
-               }
-
-               /* If the rescan pipe went active, someone is telling this
-                * thread that the &readfds needs to be refreshed with more
-                * current data.
-                */
-               if (FD_ISSET(rescan[0], &readfds)) {
-                       read(rescan[0], &junk, 1);
-                       goto SETUP_FD;
-               }
-
                /* It must be a client socket.  Find a context that has data
-                * waiting on its socket *and* is in the CON_IDLE state.
+                * waiting on its socket *and* is in the CON_IDLE state.  Any
+                * active sockets other than our chosen one are marked as
+                * CON_READY so the next thread that comes around can just bind
+                * to one without having to select() again.
                 */
-               else {
-                       bind_me = NULL;
-                       begin_critical_section(S_SESSION_TABLE);
-                       /*
-                        * We start where we left off.  If we get to the end
-                        * we'll start from the beginning again, then give up
-                        * if we still don't find anything.  This ensures
-                        * that all contexts get a more-or-less equal chance
-                        * to run. And yes, I did add a goto to the code. -IO
-                        */
-find_session:          if (next_session == NULL)
-                               next_session = ContextList;
-                       for (ptr = next_session;
-                           ( (ptr != NULL) && (bind_me == NULL) );
-                           ptr = ptr->next) {
-                               if ( (FD_ISSET(ptr->client_socket, &readfds))
-                                  && (ptr->state == CON_IDLE) ) {
-                                       bind_me = ptr;
+               begin_critical_section(S_SESSION_TABLE);
+               for (ptr = ContextList; ptr != NULL; ptr = ptr->next) {
+                       if ( (FD_ISSET(ptr->client_socket, &readfds))
+                          && (ptr->state != CON_EXECUTING) ) {
+                               ptr->input_waiting = 1;
+                               if (!bind_me) {
+                                       bind_me = ptr;  /* I choose you! */
+                                       bind_me->state = CON_EXECUTING;
+                               }
+                               else {
+                                       ptr->state = CON_READY;
                                }
                        }
-                       if (bind_me != NULL) {
-                               /* Found one.  Stake a claim to it before
-                                * letting anyone else touch the context list.
-                                */
-                               bind_me->state = CON_EXECUTING;
-                               next_session = bind_me->next;
-                       } else if (next_session == ContextList) {
-                               next_session = NULL;
-                       }
-                       if (bind_me == NULL && next_session != NULL) {
-                               next_session = NULL;
-                               goto find_session;
-                       }
+               }
+               end_critical_section(S_SESSION_TABLE);
 
-                       end_critical_section(S_SESSION_TABLE);
-                       end_critical_section(S_I_WANNA_SELECT);
+SKIP_SELECT:
+               /* We're bound to a session */
+               if (bind_me != NULL) {
+                       become_session(bind_me);
 
-                       /* We're bound to a session, now do *one* command */
-                       if (bind_me != NULL) {
-                               become_session(bind_me);
+                       /* If the client has sent a command, execute it. */
+                       if (CC->input_waiting) {
                                CC->h_command_function();
-                               become_session(NULL);
-                               bind_me->state = CON_IDLE;
-                               write(rescan[1], &junk, 1);
+                               CC->input_waiting = 0;
                        }
 
+                       /* If there are asynchronous messages waiting and the
+                        * client supports it, do those now */
+                       if ((CC->is_async) && (CC->async_waiting)
+                          && (CC->h_async_function != NULL)) {
+                               CC->h_async_function();
+                               CC->async_waiting = 0;
+                       }
+                       
+                       force_purge = CC->kill_me;
+                       become_session(NULL);
+                       bind_me->state = CON_IDLE;
                }
-               dead_session_purge();
+
+               dead_session_purge(force_purge);
                do_housekeeping();
                check_sched_shutdown();
        }
 
        /* If control reaches this point, the server is shutting down */        
-       --num_threads;
-       return NULL;
+       return(NULL);
 }
 
 
@@ -1133,7 +1213,8 @@ int SyslogFacility(char *name)
                if(!strcasecmp(name, facTbl[i].name))
                        return facTbl[i].facility;
        }
-       return -1;
+       enable_syslog = 0;
+       return LOG_DAEMON;
 }