/* idled.c - daemon for handling IMAP IDLE notifications
*
* Copyright (c) 1994-2008 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
* AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <sys/types.h>
#include <sysexits.h>
#include <syslog.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <signal.h>
#include <fcntl.h>
#include "idlemsg.h"
#include "global.h"
#include "mboxlist.h"
#include "xmalloc.h"
#include "hash.h"
extern int optind;
extern char *optarg;
static int verbose = 0;
static int debugmode = 0;
static time_t idle_timeout;
struct ientry {
struct sockaddr_un remote;
time_t itime;
struct ientry *next;
};
static struct hash_table itable;
EXPORTED void fatal(const char *msg, int err)
{
if (debugmode) fprintf(stderr, "dying with %s %d\n",msg,err);
syslog(LOG_CRIT, "%s", msg);
syslog(LOG_NOTICE, "exiting");
cyrus_done();
exit(err);
}
static int mbox_count_cb(const mbentry_t *mbentry __attribute__((unused)), void *rockp)
{
int *ip = (int *) rockp;
(*ip)++;
return 0;
}
/* remove an ientry from list of those idling on mboxname */
static void remove_ientry(const char *mboxname,
const struct sockaddr_un *remote)
{
struct ientry *t, *p = NULL;
t = (struct ientry *) hash_lookup(mboxname, &itable);
while (t && memcmp(&t->remote, remote, sizeof(*remote))) {
p = t;
t = t->next;
}
if (t) {
if (!p) {
/* first ientry in the linked list */
p = t->next; /* remove node */
/* we just removed the data that the hash entry
was pointing to, so insert the new data */
hash_insert(mboxname, p, &itable);
}
else {
/* not the first ientry in the linked list */
p->next = t->next; /* remove node */
}
free(t);
}
}
static void process_message(struct sockaddr_un *remote, idle_message_t *msg)
{
struct ientry *t, *n;
int r;
switch (msg->which) {
case IDLE_MSG_INIT:
if (verbose || debugmode)
syslog(LOG_DEBUG, "imapd[%s]: IDLE_MSG_INIT '%s'\n",
idle_id_from_addr(remote), msg->mboxname);
/* add an ientry to list of those idling on mboxname */
t = (struct ientry *) hash_lookup(msg->mboxname, &itable);
n = (struct ientry *) xzmalloc(sizeof(struct ientry));
n->remote = *remote;
n->itime = time(NULL);
n->next = t;
hash_insert(msg->mboxname, n, &itable);
break;
case IDLE_MSG_NOTIFY:
if (verbose || debugmode)
syslog(LOG_DEBUG, "IDLE_MSG_NOTIFY '%s'\n", msg->mboxname);
/* send a message to all clients idling on mboxname */
t = (struct ientry *) hash_lookup(msg->mboxname, &itable);
for ( ; t ; t = n) {
n = t->next;
if ((t->itime + idle_timeout) < time(NULL)) {
/* This process has been idling for longer than the timeout
* period, so it probably died. Remove it from the list.
*/
if (verbose || debugmode)
syslog(LOG_DEBUG, " TIMEOUT %s\n", idle_id_from_addr(&t->remote));
remove_ientry(msg->mboxname, &t->remote);
}
else { /* signal process to update */
if (verbose || debugmode)
syslog(LOG_DEBUG, " fwd NOTIFY %s\n", idle_id_from_addr(&t->remote));
/* forward the received msg onto our clients */
r = idle_send(&t->remote, msg);
if (r) {
/* ENOENT can happen as result of a race between delivering
* messages and shutting down imapd. It indicates that the
* imapd's socket was unlinked, which means that imapd went
* through it's graceful shutdown path, so don't syslog. */
if (r != ENOENT)
syslog(LOG_ERR, "IDLE: error sending message "
"NOTIFY to imapd %s for mailbox %s: %s, "
"forgetting.",
idle_id_from_addr(&t->remote),
msg->mboxname, error_message(r));
if (verbose || debugmode)
syslog(LOG_DEBUG, " forgetting %s\n", idle_id_from_addr(&t->remote));
remove_ientry(msg->mboxname, &t->remote);
}
}
}
break;
case IDLE_MSG_DONE:
if (verbose || debugmode)
syslog(LOG_DEBUG, "imapd[%s]: IDLE_MSG_DONE '%s'\n",
idle_id_from_addr(remote), msg->mboxname);
/* remove client from list of those idling on mboxname */
remove_ientry(msg->mboxname, remote);
break;
case IDLE_MSG_NOOP:
break;
default:
syslog(LOG_ERR, "unrecognized message: %lx", msg->which);
break;
}
}
static void send_alert(const char *key,
void *data,
void *rock __attribute__((unused)))
{
struct ientry *t = (struct ientry *) data;
struct ientry *n;
idle_message_t msg;
int r;
msg.which = IDLE_MSG_ALERT;
strncpy(msg.mboxname, ".", sizeof(msg.mboxname));
for ( ; t ; t = n) {
n = t->next;
/* signal process to check ALERTs */
if (verbose || debugmode)
syslog(LOG_DEBUG, " ALERT %s\n", idle_id_from_addr(&t->remote));
r = idle_send(&t->remote, &msg);
if (r) {
/* ENOENT can happen as result of a race between shutting
* down idled and shutting down imapd. It indicates that the
* imapd's socket was unlinked, which means that imapd went
* through it's graceful shutdown path, so don't syslog. */
if (r != ENOENT)
syslog(LOG_ERR, "IDLE: error sending message "
"ALERT to imapd %s for mailbox %s: %s, "
"forgetting.",
idle_id_from_addr(&t->remote),
msg.mboxname, error_message(r));
if (verbose || debugmode)
syslog(LOG_DEBUG, " forgetting %s\n", idle_id_from_addr(&t->remote));
remove_ientry(key, &t->remote);
}
}
}
static void shut_down(int ec) __attribute__((noreturn));
static void shut_down(int ec)
{
hash_enumerate(&itable, send_alert, NULL);
idle_done_sock();
cyrus_done();
exit(ec);
}
int main(int argc, char **argv)
{
char *p = NULL;
int opt;
int nmbox = 0;
int s;
struct sockaddr_un local;
fd_set read_set, rset;
int nfds;
struct timeval timeout;
pid_t pid;
char *alt_config = NULL;
p = getenv("CYRUS_VERBOSE");
if (p) verbose = atoi(p) + 1;
while ((opt = getopt(argc, argv, "C:d")) != EOF) {
switch (opt) {
case 'C': /* alt config file */
alt_config = optarg;
break;
case 'd': /* don't fork. debugging mode */
debugmode = 1;
break;
default:
fprintf(stderr, "invalid argument\n");
exit(EX_USAGE);
break;
}
}
cyrus_init(alt_config, "idled", 0, 0);
/* Set inactivity timer (minimum is 30 minutes) */
idle_timeout = config_getduration(IMAPOPT_TIMEOUT, 'm');
if (idle_timeout < 30 * 60) idle_timeout = 30 * 60;
/* count the number of mailboxes */
mboxlist_allmbox("", &mbox_count_cb, &nmbox, /*flags*/0);
signals_set_shutdown(shut_down);
signals_add_handlers(0);
/* create idle table -- +1 to avoid a zero value */
construct_hash_table(&itable, nmbox + 1, 1);
if (!idle_make_server_address(&local) ||
!idle_init_sock(&local)) {
cyrus_done();
exit(1);
}
s = idle_get_sock();
/* fork unless we were given the -d option or we're running as a daemon */
if (debugmode == 0 && !getenv("CYRUS_ISDAEMON")) {
pid = fork();
if (pid == -1) {
perror("fork");
exit(1);
}
if (pid != 0) { /* parent */
exit(0);
}
}
/* child */
/* get ready for select() */
FD_ZERO(&read_set);
FD_SET(s, &read_set);
nfds = s + 1;
for (;;) {
int n;
int sig;
sig = signals_poll();
if (sig == SIGHUP && getenv("CYRUS_ISDAEMON")) {
/* XXX maybe don't restart if we have clients? */
syslog(LOG_DEBUG, "received SIGHUP, shutting down gracefully\n");
shut_down(0);
}
/* check for shutdown file */
if (shutdown_file(NULL, 0)) {
/* signal all processes to shutdown */
if (verbose || debugmode)
syslog(LOG_DEBUG, "Detected shutdown file\n");
shut_down(1);
}
/* timeout for select is 1 second */
timeout.tv_sec = 1;
timeout.tv_usec = 0;
/* check for the next input */
rset = read_set;
n = signals_select(nfds, &rset, NULL, NULL, &timeout);
if (n < 0 && errno == EAGAIN) continue;
if (n < 0 && errno == EINTR) continue;
if (n == -1) {
/* uh oh */
syslog(LOG_ERR, "select(): %m");
close(s);
fatal("select error",-1);
}
/* read and process a message */
if (FD_ISSET(s, &rset)) {
struct sockaddr_un from;
idle_message_t msg;
if (idle_recv(&from, &msg))
process_message(&from, &msg);
}
}
/* NOTREACHED */
shut_down(1);
}