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/* $OpenBSD: delivery_lmtp.c,v 1.17 2016/06/05 12:10:28 gilles Exp $ */
/*
* Copyright (c) 2013 Ashish SHUKLA <ashish.is@lostca.se>
* Copyright (c) 2015 Sunil Nimmagadda <sunil@nimmagadda.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 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/socket.h>
#include <sys/tree.h>
#include <sys/un.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <event.h>
#include <fcntl.h>
#include <imsg.h>
#include <limits.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "smtpd.h"
/* should be more than enough for any LMTP server */
#define MAX_CONTINUATIONS 100
static int inet_socket(char *);
static int lmtp_banner(char **buf, size_t *, int, FILE *);
static int lmtp_cmd(char **buf, size_t *, int, FILE *, const char *, ...)
__attribute__((__format__ (printf, 5, 6)))
__attribute__((__nonnull__ (5)));
static void lmtp_open(struct deliver *);
static int unix_socket(char *);
struct delivery_backend delivery_backend_lmtp = {
0, lmtp_open
};
static int
inet_socket(char *address)
{
struct addrinfo hints, *res, *res0;
char *hostname, *servname;
const char *cause = NULL;
int n, s = -1, save_errno;
if ((servname = strchr(address, ':')) == NULL)
errx(1, "invalid address: %s", address);
*servname++ = '\0';
hostname = address;
memset(&hints, 0, sizeof(hints));
hints.ai_family = PF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_NUMERICSERV;
n = getaddrinfo(hostname, servname, &hints, &res0);
if (n)
errx(1, "%s", gai_strerror(n));
for (res = res0; res; res = res->ai_next) {
s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (s == -1) {
cause = "socket";
continue;
}
if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
cause = "connect";
save_errno = errno;
close(s);
errno = save_errno;
s = -1;
continue;
}
break;
}
freeaddrinfo(res0);
if (s == -1)
errx(1, "%s", cause);
return s;
}
static int
unix_socket(char *path)
{
struct sockaddr_un addr;
int s;
if ((s = socket(PF_LOCAL, SOCK_STREAM, 0)) == -1)
err(1, "socket");
memset(&addr, 0, sizeof(addr));
addr.sun_family = AF_UNIX;
if (strlcpy(addr.sun_path, path, sizeof(addr.sun_path))
>= sizeof(addr.sun_path))
errx(1, "socket path too long");
if (connect(s, (struct sockaddr *)&addr, sizeof(addr)) == -1)
err(1, "connect");
return s;
}
static void
lmtp_open(struct deliver *deliver)
{
FILE *fp;
char *buf = NULL, hn[HOST_NAME_MAX + 1],
*rcpt = deliver->to, *to = deliver->to;
size_t sz = 0;
ssize_t len;
int s;
strsep(&rcpt, " ");
s = (to[0] == '/') ? unix_socket(to) : inet_socket(to);
if ((fp = fdopen(s, "r+")) == NULL)
err(1, "fdopen");
if (lmtp_banner(&buf, &sz, '2', fp) != 0)
errx(1, "Invalid LHLO reply: %s", buf);
if (gethostname(hn, sizeof hn) == -1)
err(1, "gethostname");
if (lmtp_cmd(&buf, &sz, '2', fp, "LHLO %s", hn) != 0)
errx(1, "Invalid LHLO reply: %s", buf);
if (lmtp_cmd(&buf, &sz, '2', fp, "MAIL FROM:<%s>", deliver->from) != 0)
errx(1, "MAIL FROM rejected: %s", buf);
if (lmtp_cmd(&buf, &sz, '2', fp, "RCPT TO:<%s>",
rcpt ? deliver->dest : deliver->user) != 0)
errx(1, "RCPT TO rejected: %s", buf);
if (lmtp_cmd(&buf, &sz, '3', fp, "DATA") != 0)
errx(1, "Invalid DATA reply: %s", buf);
while ((len = getline(&buf, &sz, stdin)) != -1) {
if (buf[len - 1] == '\n')
buf[len - 1] = '\0';
if (fprintf(fp, "%s%s\r\n", buf[0] == '.' ? "." : "", buf) < 0)
errx(1, "fprintf failed");
}
if (lmtp_cmd(&buf, &sz, '2', fp, ".") != 0)
errx(1, "Delivery error: %s", buf);
if (lmtp_cmd(&buf, &sz, '2', fp, "QUIT") != 0)
errx(1, "Error on QUIT: %s", buf);
exit(0);
}
static int
lmtp_banner(char **buf, size_t *sz, int code, FILE *fp)
{
char *bufp;
ssize_t len;
size_t counter;
counter = 0;
do {
if ((len = getline(buf, sz, fp)) == -1)
err(1, "getline");
if (len < 4)
err(1, "line too short");
bufp = *buf;
if (len >= 2 && bufp[len - 2] == '\r')
bufp[len - 2] = '\0';
else if (bufp[len - 1] == '\n')
bufp[len - 1] = '\0';
if (bufp[3] == '\0' || bufp[3] == ' ')
break;
else if (bufp[3] == '-') {
if (counter == MAX_CONTINUATIONS)
errx(1, "LMTP server is sending too many continuations");
counter++;
continue;
}
else
errx(1, "invalid line");
} while (1);
return bufp[0] != code;
}
static int
lmtp_cmd(char **buf, size_t *sz, int code, FILE *fp, const char *fmt, ...)
{
va_list ap;
char *bufp;
ssize_t len;
size_t counter;
va_start(ap, fmt);
if (vfprintf(fp, fmt, ap) < 0)
errx(1, "vfprintf failed");
va_end(ap);
if (fprintf(fp, "\r\n") < 0)
errx(1, "fprintf failed");
if (fflush(fp) != 0)
err(1, "fflush");
counter = 0;
do {
if ((len = getline(buf, sz, fp)) == -1)
err(1, "getline");
if (len < 4)
err(1, "line too short");
bufp = *buf;
if (len >= 2 && bufp[len - 2] == '\r')
bufp[len - 2] = '\0';
else if (bufp[len - 1] == '\n')
bufp[len - 1] = '\0';
if (bufp[3] == '\0' || bufp[3] == ' ')
break;
else if (bufp[3] == '-') {
if (counter == MAX_CONTINUATIONS)
errx(1, "LMTP server is sending too many continuations");
counter++;
continue;
}
else
errx(1, "invalid line");
} while (1);
return bufp[0] != code;
}
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