/*	$OpenBSD: queue.c,v 1.45 2009/01/12 19:54:37 jacekm Exp $	*/

/*
 * Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
 * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, 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.
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/tree.h>
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <dirent.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "smtpd.h"

__dead void	queue_shutdown(void);
void		queue_sig_handler(int, short, void *);
void		queue_dispatch_control(int, short, void *);
void		queue_dispatch_smtp(int, short, void *);
void		queue_dispatch_mda(int, short, void *);
void		queue_dispatch_mta(int, short, void *);
void		queue_dispatch_lka(int, short, void *);
void		queue_dispatch_runner(int, short, void *);
void		queue_setup_events(struct smtpd *);
void		queue_disable_events(struct smtpd *);
void		queue_purge_incoming(void);

int		queue_create_incoming_layout(char *);
void		queue_delete_incoming_message(char *);
int		queue_record_incoming_envelope(struct message *);
int		queue_remove_incoming_envelope(struct message *);
int		queue_commit_incoming_message(struct message *);
int		queue_open_incoming_message_file(struct message *);
void		queue_message_update(struct message *);

int		queue_open_message_file(struct batch *);
void		queue_delete_message(char *);

void
queue_sig_handler(int sig, short event, void *p)
{
	switch (sig) {
	case SIGINT:
	case SIGTERM:
		queue_shutdown();
		break;
	default:
		fatalx("queue_sig_handler: unexpected signal");
	}
}

void
queue_dispatch_control(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_CONTROL];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_control: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {
		default:
			log_debug("queue_dispatch_control: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_dispatch_smtp(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_SMTP];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_smtp: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {
		case IMSG_QUEUE_CREATE_MESSAGE: {
			struct message		*messagep;
			struct submit_status	 ss;

			log_debug("mfa_dispatch_smtp: creating message file");
			messagep = imsg.data;
			ss.id = messagep->session_id;
			ss.code = 250;
			bzero(ss.u.msgid, MAXPATHLEN);

			if (! queue_create_incoming_layout(ss.u.msgid))
				ss.code = 421;

			imsg_compose(ibuf, IMSG_QUEUE_CREATE_MESSAGE, 0, 0, -1,
			    &ss, sizeof(ss));
			break;
		}
		case IMSG_QUEUE_REMOVE_MESSAGE: {
			struct message		*messagep;

			messagep = imsg.data;
			queue_delete_incoming_message(messagep->message_id);
			break;
		}
		case IMSG_QUEUE_COMMIT_MESSAGE: {
			struct message		*messagep;
			struct submit_status	 ss;

			messagep = imsg.data;
			ss.id = messagep->session_id;

			if (! queue_commit_incoming_message(messagep))
				ss.code = 421;

			imsg_compose(ibuf, IMSG_QUEUE_COMMIT_MESSAGE, 0, 0, -1,
			    &ss, sizeof(ss));

			break;
		}
		case IMSG_QUEUE_MESSAGE_FILE: {
			struct message		*messagep;
			struct submit_status	 ss;
			int fd;

			messagep = imsg.data;
			ss.id = messagep->session_id;

			fd = queue_open_incoming_message_file(messagep);
			if (fd == -1)
				ss.code = 421;

			imsg_compose(ibuf, IMSG_QUEUE_MESSAGE_FILE, 0, 0, fd,
			    &ss, sizeof(ss));
			break;
		}
		default:
			log_debug("queue_dispatch_smtp: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_dispatch_mda(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_MDA];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_mda: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {

		case IMSG_QUEUE_MESSAGE_UPDATE: {
			queue_message_update(imsg.data);
			break;
		}

		default:
			log_debug("queue_dispatch_mda: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_dispatch_mta(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_MTA];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_mda: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {

		case IMSG_QUEUE_MESSAGE_FD: {
			int fd;
			struct batch *batchp;

			batchp = imsg.data;
			fd = queue_open_message_file(batchp);
			imsg_compose(ibuf,  IMSG_QUEUE_MESSAGE_FD, 0, 0, fd, batchp,
			    sizeof(*batchp));
			break;
		}

		case IMSG_QUEUE_MESSAGE_UPDATE: {
			queue_message_update(imsg.data);
			break;
		}

		default:
			log_debug("queue_dispatch_mda: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_dispatch_lka(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_LKA];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_lka: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {

		case IMSG_QUEUE_SUBMIT_ENVELOPE: {
			struct message		*messagep;
			struct submit_status	 ss;

			messagep = imsg.data;
			messagep->id = queue_generate_id();
			ss.id = messagep->session_id;

			if (IS_MAILBOX(messagep->recipient.rule.r_action) ||
			    IS_EXT(messagep->recipient.rule.r_action))
				messagep->type = T_MDA_MESSAGE;
			else
				messagep->type = T_MTA_MESSAGE;

			/* Write to disk */
			if (! queue_record_incoming_envelope(messagep)) {
				ss.code = 421;
				imsg_compose(env->sc_ibufs[PROC_SMTP], IMSG_QUEUE_TEMPFAIL,
				    0, 0, -1, &ss, sizeof(ss));
				break;
			}

			break;
		}

		case IMSG_QUEUE_COMMIT_ENVELOPES: {
			struct message		*messagep;
			struct submit_status	 ss;

			messagep = imsg.data;
			ss.id = messagep->session_id;
			ss.code = 250;

			imsg_compose(env->sc_ibufs[PROC_SMTP], IMSG_QUEUE_COMMIT_ENVELOPES,
			    0, 0, -1, &ss, sizeof(ss));
			break;
		}

		default:
			log_debug("queue_dispatch_lka: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_dispatch_runner(int sig, short event, void *p)
{
	struct smtpd		*env = p;
	struct imsgbuf		*ibuf;
	struct imsg		 imsg;
	ssize_t			 n;

	ibuf = env->sc_ibufs[PROC_RUNNER];
	switch (event) {
	case EV_READ:
		if ((n = imsg_read(ibuf)) == -1)
			fatal("imsg_read_error");
		if (n == 0) {
			/* this pipe is dead, so remove the event handler */
			event_del(&ibuf->ev);
			event_loopexit(NULL);
			return;
		}
		break;
	case EV_WRITE:
		if (msgbuf_write(&ibuf->w) == -1)
			fatal("msgbuf_write");
		imsg_event_add(ibuf);
		return;
	default:
		fatalx("unknown event");
	}

	for (;;) {
		if ((n = imsg_get(ibuf, &imsg)) == -1)
			fatal("queue_dispatch_runner: imsg_read error");
		if (n == 0)
			break;

		switch (imsg.hdr.type) {
		default:
			log_debug("queue_dispatch_runner: unexpected imsg %d",
			    imsg.hdr.type);
			break;
		}
		imsg_free(&imsg);
	}
	imsg_event_add(ibuf);
}

void
queue_shutdown(void)
{
	log_info("queue handler");
	_exit(0);
}

void
queue_setup_events(struct smtpd *env)
{
}

void
queue_disable_events(struct smtpd *env)
{
}

pid_t
queue(struct smtpd *env)
{
	pid_t		 pid;
	struct passwd	*pw;

	struct event	 ev_sigint;
	struct event	 ev_sigterm;

	struct peer peers[] = {
		{ PROC_CONTROL,	queue_dispatch_control },
		{ PROC_SMTP,	queue_dispatch_smtp },
		{ PROC_MDA,	queue_dispatch_mda },
		{ PROC_MTA,	queue_dispatch_mta },
		{ PROC_LKA,	queue_dispatch_lka },
		{ PROC_RUNNER,	queue_dispatch_runner }
	};

	switch (pid = fork()) {
	case -1:
		fatal("queue: cannot fork");
	case 0:
		break;
	default:
		return (pid);
	}

	purge_config(env, PURGE_EVERYTHING);

	pw = env->sc_pw;

#ifndef DEBUG
	if (chroot(PATH_SPOOL) == -1)
		fatal("queue: chroot");
	if (chdir("/") == -1)
		fatal("queue: chdir(\"/\")");
#else
#warning disabling privilege revocation and chroot in DEBUG MODE
#endif

	setproctitle("queue handler");
	smtpd_process = PROC_QUEUE;

#ifndef DEBUG
	if (setgroups(1, &pw->pw_gid) ||
	    setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) ||
	    setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid))
		fatal("queue: cannot drop privileges");
#endif

	event_init();

	signal_set(&ev_sigint, SIGINT, queue_sig_handler, env);
	signal_set(&ev_sigterm, SIGTERM, queue_sig_handler, env);
	signal_add(&ev_sigint, NULL);
	signal_add(&ev_sigterm, NULL);
	signal(SIGPIPE, SIG_IGN);
	signal(SIGHUP, SIG_IGN);

	config_peers(env, peers, 6);

	queue_setup_events(env);
	queue_purge_incoming();
	event_dispatch();
	queue_shutdown();

	return (0);
}

u_int64_t
queue_generate_id(void)
{
	u_int64_t	id;
	struct timeval	tp;

	if (gettimeofday(&tp, NULL) == -1)
		fatal("queue_generate_id: time");

	id = (u_int32_t)tp.tv_sec;
	id <<= 32;
	id |= (u_int32_t)tp.tv_usec;
	usleep(1);

	return (id);
}

int
queue_remove_batch_message(struct smtpd *env, struct batch *batchp, struct message *messagep)
{
	TAILQ_REMOVE(&batchp->messages, messagep, entry);
	bzero(messagep, sizeof(struct message));
	free(messagep);

	if (TAILQ_FIRST(&batchp->messages) == NULL) {
		SPLAY_REMOVE(batchtree, &env->batch_queue, batchp);
		bzero(batchp, sizeof(struct batch));
		free(batchp);
		return 1;
	}

	return 0;
}

struct batch *
batch_by_id(struct smtpd *env, u_int64_t id)
{
	struct batch lookup;

	lookup.id = id;
	return SPLAY_FIND(batchtree, &env->batch_queue, &lookup);
}


struct message *
message_by_id(struct smtpd *env, struct batch *batchp, u_int64_t id)
{
	struct message *messagep;

	if (batchp != NULL) {
		TAILQ_FOREACH(messagep, &batchp->messages, entry) {
			if (messagep->id == id)
				break;
		}
		return messagep;
	}

	SPLAY_FOREACH(batchp, batchtree, &env->batch_queue) {
		TAILQ_FOREACH(messagep, &batchp->messages, entry) {
			if (messagep->id == id)
				return messagep;
		}
	}
	return NULL;
}

void
queue_purge_incoming(void)
{
	DIR		*dirp;
	struct dirent	*dp;

	dirp = opendir(PATH_INCOMING);
	if (dirp == NULL)
		fatal("queue_purge_incoming: opendir");

	while ((dp = readdir(dirp)) != NULL) {
		if (strcmp(dp->d_name, ".") == 0 ||
		    strcmp(dp->d_name, "..") == 0) {
			continue;
		}
		queue_delete_incoming_message(dp->d_name);
	}

	closedir(dirp);
}

int
queue_create_incoming_layout(char *message_id)
{
	char rootdir[MAXPATHLEN];
	char evpdir[MAXPATHLEN];

	if (! bsnprintf(rootdir, MAXPATHLEN, "%s/%d.XXXXXXXXXXXXXXXX",
		PATH_INCOMING, time(NULL)))
		fatalx("queue_create_incoming_layout: snprintf");

	if (mkdtemp(rootdir) == NULL) {
		if (errno == ENOSPC)
			return 0;
		fatal("queue_create_incoming_layout: mkdtemp");
	}

	if (strlcpy(message_id, rootdir + strlen(PATH_INCOMING) + 1, MAXPATHLEN)
	    >= MAXPATHLEN)
		fatalx("queue_create_incoming_layout: truncation");
	
	if (! bsnprintf(evpdir, MAXPATHLEN, "%s%s", rootdir, PATH_ENVELOPES))
		fatalx("queue_create_incoming_layout: snprintf");

	if (mkdir(evpdir, 0700) == -1) {
		if (errno == ENOSPC) {
			rmdir(rootdir);
			return 0;
		}
		fatal("queue_create_incoming_layout: mkdir");
	}

	return 1;
}

void
queue_delete_incoming_message(char *msgid)
{
	char rootdir[MAXPATHLEN];
	char purgedir[MAXPATHLEN];

	if (! bsnprintf(rootdir, MAXPATHLEN, "%s/%s", PATH_INCOMING, msgid))
		fatalx("snprintf");

	if (! bsnprintf(purgedir, MAXPATHLEN, "%s/%s", PATH_PURGE, msgid))
		fatalx("snprintf");

	if (rename(rootdir, purgedir) == -1) {
		if (errno == ENOENT)
			return;
		fatal("queue_delete_incoming_message: rename");
	}
}

int
queue_record_incoming_envelope(struct message *message)
{
	char evpname[MAXPATHLEN];
	FILE *fp;
	int fd;

again:
	if (! bsnprintf(evpname, MAXPATHLEN, "%s/%s%s/%s.%qu", PATH_INCOMING,
		message->message_id, PATH_ENVELOPES, message->message_id,
		(u_int64_t)arc4random()))
		fatalx("queue_record_incoming_envelope: snprintf");

	fd = open(evpname, O_WRONLY|O_CREAT|O_EXCL, 0600);
	if (fd == -1) {
		if (errno == EEXIST)
			goto again;
		if (errno == ENOSPC || errno == ENFILE)
			goto tempfail;
		fatal("queue_record_incoming_envelope: open");
	}

	fp = fdopen(fd, "w");
	if (fp == NULL)
		fatal("queue_record_incoming_envelope: fdopen");

	message->creation = time(NULL);
	if (strlcpy(message->message_uid, strrchr(evpname, '/') + 1, MAXPATHLEN)
	    >= MAXPATHLEN)
		fatalx("queue_record_incoming_envelope: truncation");

	if (fwrite(message, sizeof (struct message), 1, fp) != 1) {
		if (errno == ENOSPC)
			goto tempfail;
		fatal("queue_record_incoming_envelope: write");
	}

	if (! safe_fclose(fp))
		goto tempfail;

	return 1;

tempfail:
	unlink(evpname);
	close(fd);
	message->creation = 0;
	message->message_uid[0] = '\0';

	return 0;
}

int
queue_remove_incoming_envelope(struct message *message)
{
	char pathname[MAXPATHLEN];

	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%s%s/%s", PATH_INCOMING,
		message->message_id, PATH_ENVELOPES, message->message_uid))
		fatal("queue_remove_incoming_envelope: snprintf");

	if (unlink(pathname) == -1)
		if (errno != ENOENT)
			fatal("queue_remove_incoming_envelope: unlink");

	return 1;
}

int
queue_commit_incoming_message(struct message *messagep)
{
	char rootdir[MAXPATHLEN];
	char queuedir[MAXPATHLEN];
	
	if (! bsnprintf(rootdir, MAXPATHLEN, "%s/%s", PATH_INCOMING,
		messagep->message_id))
		fatal("queue_commit_message_incoming: snprintf");

	if (! bsnprintf(queuedir, MAXPATHLEN, "%s/%d", PATH_QUEUE,
		queue_hash(messagep->message_id)))
		fatal("queue_commit_message_incoming: snprintf");

	if (mkdir(queuedir, 0700) == -1) {
		if (errno == ENOSPC)
			return 0;
		if (errno != EEXIST)
			fatal("queue_commit_message_incoming: mkdir");
	}

	if (strlcat(queuedir, "/", MAXPATHLEN) >= MAXPATHLEN ||
	    strlcat(queuedir, messagep->message_id, MAXPATHLEN) >= MAXPATHLEN)
		fatalx("queue_commit_incoming_message: truncation");

	if (rename(rootdir, queuedir) == -1) {
		if (errno == ENOSPC)
			return 0;
		fatal("queue_commit_message_incoming: rename");
	}

	return 1;
}

int
queue_open_incoming_message_file(struct message *messagep)
{
	char pathname[MAXPATHLEN];
	mode_t mode = O_CREAT|O_EXCL|O_RDWR;
	
	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%s/message", PATH_INCOMING,
		messagep->message_id))
		fatal("queue_open_incoming_message_file: snprintf");

	return open(pathname, mode, 0600);
}

int
queue_remove_envelope(struct message *messagep)
{
	char pathname[MAXPATHLEN];
	u_int16_t hval;

	hval = queue_hash(messagep->message_id);

	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%d/%s%s/%s", PATH_QUEUE,
		hval, messagep->message_id, PATH_ENVELOPES,
		messagep->message_uid))
		fatal("queue_remove_envelope: snprintf");

	if (unlink(pathname) == -1)
		fatal("queue_remove_envelope: unlink");

	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%d/%s%s", PATH_QUEUE,
		hval, messagep->message_id, PATH_ENVELOPES))
		fatal("queue_remove_envelope: snprintf");

	if (rmdir(pathname) != -1)
		queue_delete_message(messagep->message_id);

	return 1;
}

int
queue_update_envelope(struct message *messagep)
{
	char temp[MAXPATHLEN];
	char dest[MAXPATHLEN];
	FILE *fp;

	if (! bsnprintf(temp, MAXPATHLEN, "%s/envelope.tmp", PATH_INCOMING))
		fatalx("queue_update_envelope");

	if (! bsnprintf(dest, MAXPATHLEN, "%s/%d/%s%s/%s", PATH_QUEUE,
		queue_hash(messagep->message_id), messagep->message_id,
		PATH_ENVELOPES, messagep->message_uid))
		fatal("queue_update_envelope: snprintf");

	fp = fopen(temp, "w");
	if (fp == NULL) {
		if (errno == ENOSPC || errno == ENFILE)
			goto tempfail;
		fatal("queue_update_envelope: open");
	}
	if (fwrite(messagep, sizeof(struct message), 1, fp) != 1) {
		if (errno == ENOSPC)
			goto tempfail;
		fatal("queue_update_envelope: fwrite");
	}
	if (! safe_fclose(fp))
		goto tempfail;

	if (rename(temp, dest) == -1) {
		if (errno == ENOSPC)
			goto tempfail;
		fatal("queue_update_envelope: rename");
	}

	return 1;

tempfail:
	if (unlink(temp) == -1)
		if (errno != ENOENT)
			fatal("queue_update_envelope: unlink");
	if (fp)
		fclose(fp);

	return 0;
}

int
queue_load_envelope(struct message *messagep, char *evpid)
{
	char pathname[MAXPATHLEN];
	char msgid[MAXPATHLEN];
	FILE *fp;

	if (strlcpy(msgid, evpid, MAXPATHLEN) >= MAXPATHLEN)
		fatalx("queue_load_envelope: truncation");
	*strrchr(msgid, '.') = '\0';

	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%d/%s%s/%s", PATH_QUEUE,
		queue_hash(msgid), msgid, PATH_ENVELOPES, evpid))
		fatalx("queue_load_envelope: snprintf");

	fp = fopen(pathname, "r");
	if (fp == NULL) {
		if (errno == ENOENT)
			return 0;
		if (errno == ENOSPC || errno == ENFILE)
			return 0;
		fatal("queue_load_envelope: fopen");
	}
	if (fread(messagep, sizeof(struct message), 1, fp) != 1)
		fatal("queue_load_envelope: fread");
	fclose(fp);

	return 1;
}

int
queue_open_message_file(struct batch *batchp)
{
	int fd;
	char pathname[MAXPATHLEN];
	mode_t mode = O_RDONLY;
	u_int16_t hval;

	hval = queue_hash(batchp->message_id);

	if (! bsnprintf(pathname, MAXPATHLEN, "%s/%d/%s/message", PATH_QUEUE,
		hval, batchp->message_id))
		fatal("queue_open_message_file: snprintf");

	if ((fd = open(pathname, mode)) == -1)
		fatal("queue_open_message_file: open");

	return fd;
}

void
queue_delete_message(char *msgid)
{
	char rootdir[MAXPATHLEN];
	char evpdir[MAXPATHLEN];
	char msgpath[MAXPATHLEN];
	u_int16_t hval;

	hval = queue_hash(msgid);
	if (! bsnprintf(rootdir, MAXPATHLEN, "%s/%d/%s", PATH_QUEUE,
		hval, msgid))
		fatal("queue_delete_message: snprintf");

	if (! bsnprintf(evpdir, MAXPATHLEN, "%s%s",
		rootdir, PATH_ENVELOPES))
		fatal("queue_delete_message: snprintf");
	
	if (! bsnprintf(msgpath, MAXPATHLEN, "%s/message", rootdir))
		fatal("queue_delete_message: snprintf");

	if (unlink(msgpath) == -1)
		if (errno != ENOENT)
			fatal("queue_delete_message: unlink");

	if (rmdir(evpdir) == -1)
		if (errno != ENOENT)
			fatal("queue_delete_message: rmdir");

	if (rmdir(rootdir) == -1)
		if (errno != ENOENT)
			fatal("queue_delete_message: rmdir");

	if (! bsnprintf(rootdir, MAXPATHLEN, "%s/%d", PATH_QUEUE,
		hval))
		fatal("queue_delete_message: snprintf");

	rmdir(rootdir);

	return;
}

void
queue_message_update(struct message *messagep)
{
	messagep->flags &= ~F_MESSAGE_PROCESSING;
	messagep->batch_id = 0;
	messagep->retry++;

	if (messagep->status & S_MESSAGE_PERMFAILURE) {
		if (messagep->type & T_DAEMON_MESSAGE)
			queue_remove_envelope(messagep);
		else {
			messagep->id = queue_generate_id();
			messagep->type |= T_DAEMON_MESSAGE;
			messagep->status &= ~S_MESSAGE_PERMFAILURE;
			messagep->lasttry = 0;
			messagep->retry = 0;
			messagep->creation = time(NULL);
			queue_update_envelope(messagep);
		}
		return;
	}

	if (messagep->status & S_MESSAGE_TEMPFAILURE) {
		messagep->status &= ~S_MESSAGE_TEMPFAILURE;
		queue_update_envelope(messagep);
		return;
	}

	/* no error, remove envelope */
	queue_remove_envelope(messagep);
}

u_int16_t
queue_hash(char *msgid)
{
	u_int16_t	h;

	for (h = 5381; *msgid; msgid++)
		h = ((h << 5) + h) + *msgid;

	return (h % DIRHASH_BUCKETS);
}