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/* $OpenBSD: mta.c,v 1.140 2012/08/30 18:16:25 eric Exp $ */
/*
* Copyright (c) 2008 Pierre-Yves Ritschard <pyr@openbsd.org>
* Copyright (c) 2008 Gilles Chehade <gilles@openbsd.org>
* Copyright (c) 2009 Jacek Masiulaniec <jacekm@dobremiasto.net>
* Copyright (c) 2012 Eric Faurot <eric@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 <ctype.h>
#include <err.h>
#include <errno.h>
#include <event.h>
#include <imsg.h>
#include <inttypes.h>
#include <netdb.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include "smtpd.h"
#include "log.h"
#define MTA_MAXCONN 5 /* connections per route */
#define MTA_MAXMAIL 100 /* mails per session */
#define MTA_MAXRCPT 1000 /* rcpt per mail */
struct mta_batch2 {
uint64_t id;
struct tree tasks; /* map route to task */
};
SPLAY_HEAD(mta_route_tree, mta_route);
static void mta_imsg(struct imsgev *, struct imsg *);
static void mta_shutdown(void);
static void mta_sig_handler(int, short, void *);
static struct mta_route *mta_route_for(struct envelope *);
static void mta_route_drain(struct mta_route *);
static void mta_route_free(struct mta_route *);
static void mta_envelope_done(struct mta_task *, struct envelope *, const char *);
static int mta_route_cmp(struct mta_route *, struct mta_route *);
SPLAY_PROTOTYPE(mta_route_tree, mta_route, entry, mta_route_cmp);
static struct mta_route_tree routes = SPLAY_INITIALIZER(&routes);
static struct tree batches = SPLAY_INITIALIZER(&batches);
void
mta_imsg(struct imsgev *iev, struct imsg *imsg)
{
struct mta_route *route;
struct mta_batch2 *batch;
struct mta_task *task;
struct envelope *e;
struct ssl *ssl;
uint64_t id;
log_imsg(PROC_MTA, iev->proc, imsg);
if (iev->proc == PROC_QUEUE) {
switch (imsg->hdr.type) {
case IMSG_BATCH_CREATE:
id = *(uint64_t*)(imsg->data);
batch = xmalloc(sizeof *batch, "mta_batch");
batch->id = id;
tree_init(&batch->tasks);
tree_xset(&batches, batch->id, batch);
log_trace(TRACE_MTA,
"mta: batch:%016" PRIx64 " created", batch->id);
return;
case IMSG_BATCH_APPEND:
e = xmalloc(sizeof *e, "mta:envelope");
memmove(e, imsg->data, sizeof *e);
route = mta_route_for(e);
batch = tree_xget(&batches, e->batch_id);
if ((task = tree_get(&batch->tasks, route->id)) == NULL) {
log_trace(TRACE_MTA, "mta: new task for %s",
mta_route_to_text(route));
task = xmalloc(sizeof *task, "mta_task");
TAILQ_INIT(&task->envelopes);
task->route = route;
tree_xset(&batch->tasks, route->id, task);
task->msgid = evpid_to_msgid(e->id);
task->sender = e->sender;
route->refcount += 1;
}
/* Technically, we could handle that by adding a msg
* level, but the batch sent by the scheduler should
* be valid.
*/
if (task->msgid != evpid_to_msgid(e->id))
errx(1, "msgid mismatch in batch");
/* XXX honour route->maxrcpt */
TAILQ_INSERT_TAIL(&task->envelopes, e, entry);
stat_increment("mta.envelope", 1);
log_debug("mta: received evp:%016" PRIx64 " for <%s@%s>",
e->id, e->dest.user, e->dest.domain);
return;
case IMSG_BATCH_CLOSE:
id = *(uint64_t*)(imsg->data);
batch = tree_xpop(&batches, id);
log_trace(TRACE_MTA, "mta: batch:%016" PRIx64 " closed",
batch->id);
/* for all tasks, queue them on there route */
while (tree_poproot(&batch->tasks, &id, (void**)&task)) {
if (id != task->route->id)
errx(1, "route id mismatch!");
task->route->refcount -= 1;
task->route->ntask += 1;
TAILQ_INSERT_TAIL(&task->route->tasks, task, entry);
stat_increment("mta.task", 1);
mta_route_drain(task->route);
}
free(batch);
return;
case IMSG_QUEUE_MESSAGE_FD:
mta_session_imsg(iev, imsg);
return;
}
}
if (iev->proc == PROC_LKA) {
switch (imsg->hdr.type) {
case IMSG_LKA_SECRET:
case IMSG_DNS_HOST:
case IMSG_DNS_HOST_END:
case IMSG_DNS_PTR:
mta_session_imsg(iev, imsg);
return;
}
}
if (iev->proc == PROC_PARENT) {
switch (imsg->hdr.type) {
case IMSG_CONF_START:
if (env->sc_flags & SMTPD_CONFIGURING)
return;
env->sc_flags |= SMTPD_CONFIGURING;
env->sc_ssl = calloc(1, sizeof *env->sc_ssl);
if (env->sc_ssl == NULL)
fatal(NULL);
return;
case IMSG_CONF_SSL:
if (!(env->sc_flags & SMTPD_CONFIGURING))
return;
ssl = calloc(1, sizeof *ssl);
if (ssl == NULL)
fatal(NULL);
*ssl = *(struct ssl *)imsg->data;
ssl->ssl_cert = xstrdup((char*)imsg->data + sizeof *ssl,
"mta:ssl_cert");
ssl->ssl_key = xstrdup((char*)imsg->data +
sizeof *ssl + ssl->ssl_cert_len, "mta_ssl_key");
SPLAY_INSERT(ssltree, env->sc_ssl, ssl);
return;
case IMSG_CONF_END:
if (!(env->sc_flags & SMTPD_CONFIGURING))
return;
env->sc_flags &= ~SMTPD_CONFIGURING;
return;
case IMSG_CTL_VERBOSE:
log_verbose(*(int *)imsg->data);
return;
}
}
errx(1, "mta_imsg: unexpected %s imsg", imsg_to_str(imsg->hdr.type));
}
static void
mta_sig_handler(int sig, short event, void *p)
{
switch (sig) {
case SIGINT:
case SIGTERM:
mta_shutdown();
break;
default:
fatalx("mta_sig_handler: unexpected signal");
}
}
static void
mta_shutdown(void)
{
log_info("mail transfer agent exiting");
_exit(0);
}
pid_t
mta(void)
{
pid_t pid;
struct passwd *pw;
struct event ev_sigint;
struct event ev_sigterm;
struct peer peers[] = {
{ PROC_PARENT, imsg_dispatch },
{ PROC_QUEUE, imsg_dispatch },
{ PROC_LKA, imsg_dispatch },
{ PROC_CONTROL, imsg_dispatch }
};
switch (pid = fork()) {
case -1:
fatal("mta: cannot fork");
case 0:
break;
default:
return (pid);
}
purge_config(PURGE_EVERYTHING);
pw = env->sc_pw;
if (chroot(pw->pw_dir) == -1)
fatal("mta: chroot");
if (chdir("/") == -1)
fatal("mta: chdir(\"/\")");
smtpd_process = PROC_MTA;
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("mta: cannot drop privileges");
imsg_callback = mta_imsg;
event_init();
signal_set(&ev_sigint, SIGINT, mta_sig_handler, NULL);
signal_set(&ev_sigterm, SIGTERM, mta_sig_handler, NULL);
signal_add(&ev_sigint, NULL);
signal_add(&ev_sigterm, NULL);
signal(SIGPIPE, SIG_IGN);
signal(SIGHUP, SIG_IGN);
config_pipes(peers, nitems(peers));
config_peers(peers, nitems(peers));
if (event_dispatch() < 0)
fatal("event_dispatch");
mta_shutdown();
return (0);
}
const char *
mta_response_status(const char *r)
{
switch (r[0]) {
case '2':
return "Sent";
case '4':
case '5':
return "RemoteError";
default:
return "LocalError";
}
}
int
mta_response_delivery(const char *r)
{
switch (r[0]) {
case '2':
return IMSG_QUEUE_DELIVERY_OK;
case '5':
case '6':
if (r[1] == '4' && r[2] == '6')
return IMSG_QUEUE_DELIVERY_LOOP;
return IMSG_QUEUE_DELIVERY_PERMFAIL;
default:
return IMSG_QUEUE_DELIVERY_TEMPFAIL;
}
}
const char *
mta_response_text(const char *r)
{
return (r + 4);
}
void
mta_route_error(struct mta_route *route, const char *error)
{
route->nfail += 1;
strlcpy(route->errorline, error, sizeof route->errorline);
log_warnx("mta: %s error: %s", mta_route_to_text(route), error);
}
void
mta_route_ok(struct mta_route *route)
{
log_debug("mta: %s ready", mta_route_to_text(route));
route->nfail = 0;
}
void
mta_route_collect(struct mta_route *route)
{
route->nsession -= 1;
mta_route_drain(route);
}
const char *
mta_route_to_text(struct mta_route *route)
{
static char buf[1024];
const char *sep = "";
buf[0] = '\0';
snprintf(buf, sizeof buf, "route:%s[", route->hostname);
if (route->flags & ROUTE_STARTTLS) {
sep = ",";
strlcat(buf, "starttls", sizeof buf);
}
if (route->flags & ROUTE_SMTPS) {
strlcat(buf, sep, sizeof buf);
sep = ",";
strlcat(buf, "smtps", sizeof buf);
}
if (route->flags & ROUTE_AUTH) {
strlcat(buf, sep, sizeof buf);
sep = ",";
strlcat(buf, "auth=", sizeof buf);
strlcat(buf, route->auth, sizeof buf);
}
if (route->cert) {
strlcat(buf, sep, sizeof buf);
sep = ",";
strlcat(buf, "cert=", sizeof buf);
strlcat(buf, route->cert, sizeof buf);
}
if (route->flags & ROUTE_MX) {
strlcat(buf, sep, sizeof buf);
sep = ",";
strlcat(buf, "mx", sizeof buf);
}
if (route->flags & ROUTE_BACKUP) {
strlcat(buf, sep, sizeof buf);
sep = ",";
strlcat(buf, "backup=", sizeof buf);
strlcat(buf, route->backupname, sizeof buf);
}
strlcat(buf, "]", sizeof buf);
return (buf);
}
static struct mta_route *
mta_route_for(struct envelope *e)
{
struct ssl ssl;
struct mta_route key, *route;
bzero(&key, sizeof key);
key.flags = e->agent.mta.relay.flags;
if (e->agent.mta.relay.flags & ROUTE_BACKUP) {
key.hostname = e->dest.domain;
key.backupname = e->agent.mta.relay.hostname;
} else if (e->agent.mta.relay.hostname[0]) {
key.hostname = e->agent.mta.relay.hostname;
key.flags |= ROUTE_MX;
} else
key.hostname = e->dest.domain;
key.port = e->agent.mta.relay.port;
key.cert = e->agent.mta.relay.cert;
if (!key.cert[0])
key.cert = NULL;
key.auth = e->agent.mta.relay.authmap;
if (!key.auth[0])
key.auth = NULL;
if ((route = SPLAY_FIND(mta_route_tree, &routes, &key)) == NULL) {
route = xcalloc(1, sizeof *route, "mta_route");
TAILQ_INIT(&route->tasks);
route->id = generate_uid();
route->flags = key.flags;
route->hostname = xstrdup(key.hostname, "mta: hostname");
route->backupname = key.backupname ?
xstrdup(key.backupname, "mta: backupname") : NULL;
route->port = key.port;
route->cert = key.cert ? xstrdup(key.cert, "mta: cert") : NULL;
route->auth = key.auth ? xstrdup(key.auth, "mta: auth") : NULL;
if (route->cert) {
strlcpy(ssl.ssl_name, route->cert, sizeof(ssl.ssl_name));
route->ssl = SPLAY_FIND(ssltree, env->sc_ssl, &ssl);
}
SPLAY_INSERT(mta_route_tree, &routes, route);
route->maxconn = MTA_MAXCONN;
route->maxmail = MTA_MAXMAIL;
route->maxrcpt = MTA_MAXRCPT;
log_trace(TRACE_MTA, "mta: new %s", mta_route_to_text(route));
stat_increment("mta.route", 1);
} else {
log_trace(TRACE_MTA, "mta: reusing %s", mta_route_to_text(route));
}
return (route);
}
static void
mta_route_free(struct mta_route *route)
{
log_trace(TRACE_MTA, "mta: freeing %s", mta_route_to_text(route));
SPLAY_REMOVE(mta_route_tree, &routes, route);
free(route->hostname);
if (route->cert)
free(route->cert);
if (route->auth)
free(route->auth);
free(route);
}
static void
mta_route_drain(struct mta_route *route)
{
struct mta_task *task;
struct envelope *e;
log_debug("mta: draining %s (tasks=%i, refs=%i, sessions=%i)",
mta_route_to_text(route),
route->ntask, route->refcount, route->nsession);
if (route->ntask == 0 && route->refcount == 0 && route->nsession == 0) {
mta_route_free(route);
stat_decrement("mta.route", 1);
return;
}
if (route->ntask == 0) {
log_debug("mta: no task for %s", mta_route_to_text(route));
return;
}
if (route->nfail > 3) {
/* Three connection errors in a row: consider that the route
* has a problem.
*/
log_debug("mta: too many failures on %s",
mta_route_to_text(route));
while ((task = TAILQ_FIRST(&route->tasks))) {
TAILQ_REMOVE(&route->tasks, task, entry);
route->ntask -= 1;
while((e = TAILQ_FIRST(&task->envelopes)))
mta_envelope_done(task, e, route->errorline);
free(task);
stat_decrement("mta.task", 1);
}
route->nfail = 0;
/* XXX maybe close the route for while */
return;
}
/* make sure there are one session for each task */
while (route->nsession < route->ntask) {
/* if we have reached the max number of session, wait */
if (route->nsession >= route->maxconn) {
log_debug("mta: max conn reached for %s",
mta_route_to_text(route));
return;
}
route->nsession += 1;
mta_session(route);
}
}
static void
mta_envelope_done(struct mta_task *task, struct envelope *e, const char *status)
{
envelope_set_errormsg(e, "%s", status);
log_info("%016" PRIx64 ": to=<%s@%s>, delay=%s, relay=%s, stat=%s (%s)",
e->id, e->dest.user,
e->dest.domain,
duration_to_text(time(NULL) - e->creation),
task->route->hostname,
mta_response_status(e->errorline),
mta_response_text(e->errorline));
imsg_compose_event(env->sc_ievs[PROC_QUEUE],
mta_response_delivery(e->errorline), 0, 0, -1, e, sizeof(*e));
TAILQ_REMOVE(&task->envelopes, e, entry);
free(e);
stat_decrement("mta.envelope", 1);
}
static int
mta_route_cmp(struct mta_route *a, struct mta_route *b)
{
int r;
if (a->flags < b->flags)
return (-1);
if (a->flags > b->flags)
return (1);
if (a->port < b->port)
return (-1);
if (a->port > b->port)
return (1);
if (a->auth == NULL && b->auth)
return (-1);
if (a->auth && b->auth == NULL)
return (1);
if (a->auth && ((r = strcmp(a->auth, b->auth))))
return (r);
if (a->cert == NULL && b->cert)
return (-1);
if (a->cert && b->cert == NULL)
return (1);
if (a->cert && ((r = strcmp(a->cert, b->cert))))
return (r);
if (a->backupname && ((r = strcmp(a->backupname, b->backupname))))
return (r);
if ((r = strcmp(a->hostname, b->hostname)))
return (r);
return (0);
}
SPLAY_GENERATE(mta_route_tree, mta_route, entry, mta_route_cmp);
|