/*	$OpenBSD: queue.c,v 1.94 2010/11/28 15:32:00 gilles 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 <event.h>
#include <imsg.h>
#include <libgen.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "smtpd.h"
#include "log.h"

void		queue_imsg(struct smtpd *, struct imsgev *, struct imsg *);
void		queue_pass_to_runner(struct smtpd *, struct imsgev *, struct imsg *);
__dead void	queue_shutdown(void);
void		queue_sig_handler(int, short, void *);
void		queue_purge(char *);

int		queue_create_layout_message(char *, char *);
void		queue_delete_layout_message(char *, char *);
int		queue_record_layout_envelope(char *, struct message *);
int		queue_remove_layout_envelope(char *, struct message *);
int		queue_commit_layout_message(char *, struct message *);
int		queue_open_layout_messagefile(char *, struct message *);

void
queue_imsg(struct smtpd *env, struct imsgev *iev, struct imsg *imsg)
{
	struct submit_status	 ss;
	struct message		*m;
	struct batch		*b;
	int			 fd, ret;

	if (iev->proc == PROC_SMTP) {
		m = imsg->data;

		switch (imsg->hdr.type) {
		case IMSG_QUEUE_CREATE_MESSAGE:
			ss.id = m->session_id;
			ss.code = 250;
			bzero(ss.u.msgid, sizeof ss.u.msgid);
			if (m->flags & F_MESSAGE_ENQUEUED)
				ret = enqueue_create_layout(ss.u.msgid);
			else
				ret = queue_create_incoming_layout(ss.u.msgid);
			if (ret == 0)
				ss.code = 421;
			imsg_compose_event(iev, IMSG_QUEUE_CREATE_MESSAGE, 0, 0, -1,
			    &ss, sizeof ss);
			return;

		case IMSG_QUEUE_REMOVE_MESSAGE:
			if (m->flags & F_MESSAGE_ENQUEUED)
				enqueue_delete_message(m->message_id);
			else
				queue_delete_incoming_message(m->message_id);
			return;

		case IMSG_QUEUE_COMMIT_MESSAGE:
			ss.id = m->session_id;
			if (m->flags & F_MESSAGE_ENQUEUED) {
				if (enqueue_commit_message(m))
					env->stats->queue.inserts_local++;
				else
					ss.code = 421;
			} else {
				if (queue_commit_incoming_message(m))
					env->stats->queue.inserts_remote++;
				else
					ss.code = 421;
			}
			imsg_compose_event(iev, IMSG_QUEUE_COMMIT_MESSAGE, 0, 0, -1,
			    &ss, sizeof ss);
			return;

		case IMSG_QUEUE_MESSAGE_FILE:
			ss.id = m->session_id;
			if (m->flags & F_MESSAGE_ENQUEUED)
				fd = enqueue_open_messagefile(m);
			else
				fd = queue_open_incoming_message_file(m);
			if (fd == -1)
				ss.code = 421;
			imsg_compose_event(iev, IMSG_QUEUE_MESSAGE_FILE, 0, 0, fd,
			    &ss, sizeof ss);
			return;

		case IMSG_SMTP_ENQUEUE:
			queue_pass_to_runner(env, iev, imsg);
			return;
		}
	}

	if (iev->proc == PROC_LKA) {
		m = imsg->data;

		switch (imsg->hdr.type) {
		case IMSG_QUEUE_SUBMIT_ENVELOPE:
			m->id = generate_uid();
			ss.id = m->session_id;

			if (IS_MAILBOX(m->recipient) || IS_EXT(m->recipient))
				m->type = T_MDA_MESSAGE;
			else
				m->type = T_MTA_MESSAGE;

			/* Write to disk */
			if (m->flags & F_MESSAGE_ENQUEUED)
				ret = enqueue_record_envelope(m);
			else
				ret = queue_record_incoming_envelope(m);

			if (ret == 0) {
				ss.code = 421;
				imsg_compose_event(env->sc_ievs[PROC_SMTP],
				    IMSG_QUEUE_TEMPFAIL, 0, 0, -1, &ss,
				    sizeof ss);
			}
			return;

		case IMSG_QUEUE_COMMIT_ENVELOPES:
			ss.id = m->session_id;
			ss.code = 250;
			imsg_compose_event(env->sc_ievs[PROC_SMTP],
			    IMSG_QUEUE_COMMIT_ENVELOPES, 0, 0, -1, &ss,
			    sizeof ss);
			return;
		}
	}

	if (iev->proc == PROC_RUNNER) {
		/* forward imsgs from runner on its behalf */
		imsg_compose_event(env->sc_ievs[imsg->hdr.peerid], imsg->hdr.type,
		    0, imsg->hdr.pid, imsg->fd, (char *)imsg->data,
		    imsg->hdr.len - sizeof imsg->hdr);
		return;
	}

	if (iev->proc == PROC_MTA) {
		switch (imsg->hdr.type) {
		case IMSG_QUEUE_MESSAGE_FD:
			b = imsg->data;
			fd = queue_open_message_file(b->message_id);
			imsg_compose_event(iev,  IMSG_QUEUE_MESSAGE_FD, 0, 0,
			    fd, b, sizeof *b);
			return;

		case IMSG_QUEUE_MESSAGE_UPDATE:
		case IMSG_BATCH_DONE:
			queue_pass_to_runner(env, iev, imsg);
			return;
		}
	}

	if (iev->proc == PROC_MDA) {
		switch (imsg->hdr.type) {
		case IMSG_QUEUE_MESSAGE_UPDATE:
		case IMSG_MDA_SESS_NEW:
			queue_pass_to_runner(env, iev, imsg);
			return;
		}
	}

	if (iev->proc == PROC_CONTROL) {
		switch (imsg->hdr.type) {
		case IMSG_QUEUE_PAUSE_LOCAL:
		case IMSG_QUEUE_PAUSE_OUTGOING:
		case IMSG_QUEUE_RESUME_LOCAL:
		case IMSG_QUEUE_RESUME_OUTGOING:
		case IMSG_QUEUE_SCHEDULE:
		case IMSG_QUEUE_REMOVE:
			queue_pass_to_runner(env, iev, imsg);
			return;
		}
	}

	if (iev->proc == PROC_PARENT) {
		switch (imsg->hdr.type) {
		case IMSG_PARENT_ENQUEUE_OFFLINE:
			queue_pass_to_runner(env, iev, imsg);
			return;

		case IMSG_CTL_VERBOSE:
			log_verbose(*(int *)imsg->data);
			queue_pass_to_runner(env, iev, imsg);
			return;
		}
	}

	fatalx("queue_imsg: unexpected imsg");
}

void
queue_pass_to_runner(struct smtpd *env, struct imsgev *iev, struct imsg *imsg)
{
	imsg_compose_event(env->sc_ievs[PROC_RUNNER], imsg->hdr.type,
	    iev->proc, imsg->hdr.pid, imsg->fd, imsg->data,
	    imsg->hdr.len - sizeof imsg->hdr);
}

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

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

	struct event	 ev_sigint;
	struct event	 ev_sigterm;

	struct peer peers[] = {
		{ PROC_PARENT,	imsg_dispatch },
		{ PROC_CONTROL,	imsg_dispatch },
		{ PROC_SMTP,	imsg_dispatch },
		{ PROC_MDA,	imsg_dispatch },
		{ PROC_MTA,	imsg_dispatch },
		{ PROC_LKA,	imsg_dispatch },
		{ PROC_RUNNER,	imsg_dispatch }
	};

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

	purge_config(env, PURGE_EVERYTHING);

	pw = env->sc_pw;

	if (chroot(PATH_SPOOL) == -1)
		fatal("queue: chroot");
	if (chdir("/") == -1)
		fatal("queue: chdir(\"/\")");

	smtpd_process = PROC_QUEUE;
	setproctitle("%s", env->sc_title[smtpd_process]);

	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");

	imsg_callback = queue_imsg;
	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);

	/*
	 * queue opens fds for four purposes: smtp, mta, mda, and bounces.
	 * Therefore, use all available fd space and set the maxconn (=max
	 * session count for mta and mda) to a quarter of this value.
	 */
	fdlimit(1.0);
	if ((env->sc_maxconn = availdesc() / 4) < 1)
		fatalx("runner: fd starvation");

	config_pipes(env, peers, nitems(peers));
	config_peers(env, peers, nitems(peers));

	queue_purge(PATH_INCOMING);
	queue_purge(PATH_ENQUEUE);

	if (event_dispatch() <  0)
		fatal("event_dispatch");
	queue_shutdown();

	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);
}


void
queue_purge(char *queuepath)
{
	char		 path[MAXPATHLEN];
	struct qwalk	*q;

	q = qwalk_new(queuepath);

	while (qwalk(q, path))
		queue_delete_layout_message(queuepath, basename(path));

	qwalk_close(q);
}

void
queue_submit_envelope(struct smtpd *env, struct message *message)
{
	imsg_compose_event(env->sc_ievs[PROC_QUEUE],
	    IMSG_QUEUE_SUBMIT_ENVELOPE, 0, 0, -1,
	    message, sizeof(struct message));
}

void
queue_commit_envelopes(struct smtpd *env, struct message *message)
{
	imsg_compose_event(env->sc_ievs[PROC_QUEUE],
	    IMSG_QUEUE_COMMIT_ENVELOPES, 0, 0, -1,
	    message, sizeof(struct message));
}