/* proxy.c - proxy support functions
*
* Copyright (c) 1994-2008 Carnegie Mellon University. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The name "Carnegie Mellon University" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For permission or any legal
* details, please contact
* Carnegie Mellon University
* Center for Technology Transfer and Enterprise Creation
* 4615 Forbes Avenue
* Suite 302
* Pittsburgh, PA 15213
* (412) 268-7393, fax: (412) 268-7395
* innovation@andrew.cmu.edu
*
* 4. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by Computing Services
* at Carnegie Mellon University (http://www.cmu.edu/computing/)."
*
* CARNEGIE MELLON UNIVERSITY DISCLAIMS ALL WARRANTIES WITH REGARD TO
* THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS, IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY BE LIABLE
* FOR ANY SPECIAL, 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 <config.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <syslog.h>
#include <sys/un.h>
#include "backend.h"
#include "exitcodes.h"
#include "global.h"
#include "mupdate-client.h"
#include "proxy.h"
#include "xmalloc.h"
#include "xstrlcpy.h"
/* generated headers are not necessarily in current directory */
#include "imap/imap_err.h"
EXPORTED void proxy_adddest(struct dest **dlist, const char *rcpt, int rcpt_num,
const char *server, const char *authas)
{
struct dest *d;
/* see if we currently have a 'mailboxdata->server'/'authas'
combination. */
for (d = *dlist; d != NULL; d = d->next) {
if (!strcmp(d->server, server) &&
!strcmp(d->authas, authas ? authas : "")) break;
}
if (d == NULL) {
/* create a new one */
d = xmalloc(sizeof(struct dest));
strlcpy(d->server, server, sizeof(d->server));
strlcpy(d->authas, authas ? authas : "", sizeof(d->authas));
d->rnum = 0;
d->to = NULL;
d->next = *dlist;
*dlist = d;
}
if (rcpt) {
struct rcpt *new_rcpt = xmalloc(sizeof(struct rcpt));
strlcpy(new_rcpt->rcpt, rcpt, sizeof(new_rcpt->rcpt));
new_rcpt->rcpt_num = rcpt_num;
/* add rcpt to d */
d->rnum++;
new_rcpt->next = d->to;
d->to = new_rcpt;
}
}
EXPORTED void proxy_downserver(struct backend *s)
{
if (!s || (s->sock == -1)) {
/* already disconnected */
return;
}
/* need to logout of server */
backend_disconnect(s);
/* clear any references to this backend */
if (s->inbox && (s == *(s->inbox))) *(s->inbox) = NULL;
if (s->current && (s == *(s->current))) *(s->current) = NULL;
s->inbox = s->current = NULL;
/* remove the timeout */
if (s->timeout) prot_removewaitevent(s->clientin, s->timeout);
s->timeout = NULL;
s->clientin = NULL;
}
static struct prot_waitevent *
backend_timeout(struct protstream *s __attribute__((unused)),
struct prot_waitevent *ev, void *rock)
{
struct backend *be = (struct backend *) rock;
int is_active = (be->context ? *((int *) be->context) : 0);
if ((!be->current || (be != *(be->current))) && !is_active) {
/* server is not our current server, and idle too long.
* down the backend server (removes the event as a side-effect)
*/
proxy_downserver(be);
return NULL;
}
else {
/* it will timeout in IDLE_TIMEOUT seconds from now */
ev->mark = time(NULL) + IDLE_TIMEOUT;
return ev;
}
}
/* return the connection to the server */
EXPORTED struct backend * proxy_findserver(const char *server, /* hostname of backend */
struct protocol_t *prot, /* protocol we're speaking */
const char *userid, /* proxy as userid (ext form)*/
struct backend ***cache, /* ptr to backend cache */
struct backend **current, /* ptr to current backend */
struct backend **inbox, /* ptr to inbox backend */
struct protstream *clientin) /* protstream from client to
proxy (if non-NULL a timeout
will be setup) */
{
int i = 0;
struct backend *ret = NULL;
if (current && *current && !strcmp(server, (*current)->hostname)
&& !strcmp(prot->service, (*current)->prot->service)) {
/* this is our current backend */
return *current;
}
/* check if we already a connection to this backend */
while (cache && *cache && (*cache)[i]) {
if ((!strcmp(server, ((*cache)[i])->hostname) &&
!strcmp(prot->service, ((*cache)[i])->prot->service))) {
ret = (*cache)[i];
/* ping/noop the server */
if ((ret->sock != -1) && backend_ping(ret, userid)) {
backend_disconnect(ret);
}
break;
}
i++;
}
if (!ret || (ret->sock == -1)) {
/* need to (re)establish connection to server or create one */
ret = backend_connect(ret, server, prot, userid, NULL, NULL, -1);
if (!ret) return NULL;
if (clientin) {
/* add the timeout */
ret->clientin = clientin;
ret->timeout = prot_addwaitevent(clientin,
time(NULL) + IDLE_TIMEOUT,
backend_timeout, ret);
ret->timeout->mark = time(NULL) + IDLE_TIMEOUT;
}
}
ret->current = current;
ret->inbox = inbox;
/* insert server in list of cache connections */
if (cache && (!*cache || !(*cache)[i])) {
*cache = (struct backend **)
xrealloc(*cache, (i + 2) * sizeof(struct backend *));
(*cache)[i] = ret;
(*cache)[i + 1] = NULL;
}
return ret;
}
/*
* Check a protgroup for input.
*
* Input from serverin is sent to clientout.
* If serverout is non-NULL:
* - input from clientin is sent to serverout.
* - returns -1 if clientin or serverin closed, otherwise returns 0.
* If serverout is NULL:
* - returns 1 if input from clientin is pending, otherwise returns 0.
*/
EXPORTED int proxy_check_input(struct protgroup *protin,
struct protstream *clientin,
struct protstream *clientout,
struct protstream *serverin,
struct protstream *serverout,
unsigned long timeout_sec)
{
struct protgroup *protout = NULL;
struct timeval timeout = { timeout_sec, 0 };
int n, ret = 0;
n = prot_select(protin, PROT_NO_FD, &protout, NULL,
timeout_sec ? &timeout : NULL);
if (n == -1 && errno != EINTR) {
syslog(LOG_ERR, "prot_select() failed in proxy_check_input(): %m");
fatal("prot_select() failed in proxy_check_input()", EC_TEMPFAIL);
}
if (n && protout) {
/* see who has input */
for (; n; n--) {
struct protstream *pin = protgroup_getelement(protout, n-1);
struct protstream *pout = NULL;
if (pin == clientin) {
/* input from client */
if (serverout) {
/* stream it to server */
pout = serverout;
} else {
/* notify the caller */
ret = 1;
}
}
else if (pin == serverin) {
/* input from server, stream it to client */
pout = clientout;
}
else {
/* XXX shouldn't get here !!! */
fatal("unknown protstream returned by prot_select in proxy_check_input()",
EC_SOFTWARE);
}
if (pout) {
const char *err;
do {
char buf[4096];
int c = prot_read(pin, buf, sizeof(buf));
if (c == 0 || c < 0) break;
prot_write(pout, buf, c);
} while (pin->cnt > 0);
if ((err = prot_error(pin)) != NULL) {
if (serverout && !strcmp(err, PROT_EOF_STRING)) {
/* we're pipelining, and the connection closed */
ret = -1;
}
else {
/* uh oh, we're not happy */
fatal("Lost connection to input stream",
EC_UNAVAILABLE);
}
}
else {
return 0;
}
}
}
protgroup_free(protout);
}
return ret;
}