/* $Id: deliver-smtp.c,v 1.53 2007/08/18 12:19:43 nicm Exp $ */

/*
 * Copyright (c) 2006 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * 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 MIND, 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/param.h>

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "fdm.h"
#include "deliver.h"

int	 deliver_smtp_deliver(struct deliver_ctx *, struct actitem *);
void	 deliver_smtp_desc(struct actitem *, char *, size_t);

int	 deliver_smtp_code(char *);

struct deliver deliver_smtp = {
	"smtp",
	DELIVER_ASUSER,
	deliver_smtp_deliver,
	deliver_smtp_desc
};

int
deliver_smtp_code(char *line)
{
	char		 ch;
	const char	*errstr;
	int	 	 n;
	size_t		 len;

	len = strspn(line, "0123456789");
	if (len == 0)
		return (-1);
	ch = line[len];
	line[len] = '\0';

	n = strtonum(line, 100, 999, &errstr);
	line[len] = ch;
	if (errstr != NULL)
		return (-1);

	return (n);
}

int
deliver_smtp_deliver(struct deliver_ctx *dctx, struct actitem *ti)
{
	struct account			*a = dctx->account;
	struct mail			*m = dctx->mail;
	struct deliver_smtp_data	*data = ti->data;
	int		 		 done, code;
	struct io			*io;
	char				*cause, *to, *from, *line, *ptr, *lbuf;
	enum deliver_smtp_state		 state;
	size_t		 		 len, llen;

	io = connectproxy(&data->server,
	    conf.verify_certs, conf.proxy, IO_CRLF, conf.timeout, &cause);
	if (io == NULL) {
		log_warnx("%s: %s", a->name, cause);
		xfree(cause);
		return (DELIVER_FAILURE);
	}
	if (conf.debug > 3 && !conf.syslog)
		io->dup_fd = STDOUT_FILENO;

	xasprintf(&from, "%s@%s", conf.info.user, conf.info.host);
	if (data->to.str == NULL)
		to = xstrdup(from);
	else {
		to = replacestr(&data->to, m->tags, m, &m->rml);
		if (to == NULL || *to == '\0') {
			log_warnx("%s: empty to", a->name);
			goto error;
		}
	}

	llen = IO_LINESIZE;
	lbuf = xmalloc(llen);

	state = SMTP_CONNECTING;
	line = cause = NULL;
	done = 0;
	do {
		switch (io_pollline2(io,
		    &line, &lbuf, &llen, conf.timeout, &cause)) {
		case 0:
			cause = xstrdup("connection unexpectedly closed");
			goto error;
		case -1:
			goto error;
		}
		code = deliver_smtp_code(line);

		switch (state) {
		case SMTP_CONNECTING:
			if (code != 220)
				goto error;
			state = SMTP_HELO;
			io_writeline(io, "HELO %s", conf.info.host);
			break;
		case SMTP_HELO:
			if (code != 250)
				goto error;
			state = SMTP_FROM;
			io_writeline(io, "MAIL FROM:%s", from);
			break;
		case SMTP_FROM:
			if (code != 250)
				goto error;
			state = SMTP_TO;
			io_writeline(io, "RCPT TO:%s", to);
			break;
		case SMTP_TO:
			if (code != 250)
				goto error;
			state = SMTP_DATA;
			io_writeline(io, "DATA");
			break;
		case SMTP_DATA:
			if (code != 354)
				goto error;
			line_init(m, &ptr, &len);
			while (ptr != NULL) {
				if (len > 1)
					io_write(io, ptr, len - 1);
				io_writeline(io, NULL);

				/* Update if necessary. */
				if (io_update(io, conf.timeout, &cause) != 1)
					goto error;

				line_next(m, &ptr, &len);
			}
			state = SMTP_DONE;
			io_writeline(io, ".");
			io_flush(io, conf.timeout, NULL);
			break;
		case SMTP_DONE:
			if (code != 250)
				goto error;
			state = SMTP_QUIT;
			io_writeline(io, "QUIT");
			break;
		case SMTP_QUIT:
			/*
			 * Exchange sometimes refuses to accept QUIT as a valid
			 * command, but since we got a 250 the mail has been
			 * accepted. So, allow 500 here too.
			 */
			if (code != 500 && code != 221)
				goto error;
			done = 1;
			break;
		}
	} while (!done);

	xfree(lbuf);
	xfree(from);
	xfree(to);

	io_close(io);
	io_free(io);

	return (DELIVER_SUCCESS);

error:
	if (cause != NULL) {
		log_warnx("%s: %s", a->name, cause);
		xfree(cause);
	} else
		log_warnx("%s: unexpected response: %s", a->name, line);

	io_writeline(io, "QUIT");
	io_flush(io, conf.timeout, NULL);

	xfree(lbuf);
	if (from != NULL)
		xfree(from);
	if (to != NULL)
		xfree(to);

	io_close(io);
	io_free(io);

	return (DELIVER_FAILURE);
}

void
deliver_smtp_desc(struct actitem *ti, char *buf, size_t len)
{
	struct deliver_smtp_data	*data = ti->data;

	xsnprintf(buf, len, "smtp%s server \"%s\" port %s to \"%s\"",
	    data->server.ssl ? "s" : "", data->server.host, data->server.port,
	    data->to.str);
}