Viewing file: 
esmtp.c (7.83 KB) -rw-rw-rw-Select action/file-type:
(
+) |
(
+) |
(
+) |
Code (
+) |
Session (
+) |
(
+) |
SDB (
+) |
(
+) |
(
+) |
(
+) |
(
+) |
(
+) |
/*
** Copyright 1998 - 2002 Double Precision, Inc.
** See COPYING for distribution information.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include "courier.h"
#include "rw.h"
#include "rfc822.h"
#include "dbobj.h"
#include "comfax.h"
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
static int acceptdomain(const struct rfc822token *);
static void rw_esmtp(struct rw_info *, void (*)(struct rw_info *));
static void rw_del_esmtp(struct rw_info *, void (*)(struct rw_info *),
void (*)(struct rw_info *, const struct rfc822token *,
const struct rfc822token *));
struct rw_list *esmtp_rw_install(const struct rw_install_info *p)
{
static struct rw_list esmtp_info={0, "module.esmtp - " COURIER_COPYRIGHT,
rw_esmtp, rw_del_esmtp, 0};
return (&esmtp_info);
}
const char *esmtp_rw_init()
{
return (0);
}
static struct rfc822token *rfc822check(int err_code,
struct rw_info *info, int allow_faxdomain)
{
struct rfc822token *p, *s;
for (p=0, s=info->ptr; s; s=s->next)
if (s->token == '@') p=s;
if (p)
{
int seendot=1;
int seen1dot=0;
int dummy;
for (s=p->next; s; s=s->next)
{
if (s->token == 0)
{
if (!seendot) break;
seendot=0;
}
else if (s->token == '.')
{
if (seendot) break;
seendot=1;
seen1dot=1;
}
else break;
}
/*
** Normally, @fax-lowres would trip the above check.
** If rfc822check is being called to validate the recipient
** address, relax this syntax check.
*/
if (s == 0 && !seen1dot && allow_faxdomain &&
p->next && !p->next->next && p->next->token == 0 &&
comgetfaxoptsn(p->next->ptr, p->next->len, &dummy) == 0 &&
getenv("FAXRELAYCLIENT") != NULL)
return (p);
if (s == 0 && seen1dot) return (p);
}
(*info->err_func)(err_code, "Syntax error.", info);
return (0);
}
static int rwrecip(struct rw_info *info)
{
struct rfc822token *p, *q;
if (rfc822check(513, info, 1) == 0) return (-1);
/*
Rewrite @foobar:foo@bar into foo@bar if @foobar is us.
*/
for (;;)
{
if (info->ptr == 0 || info->ptr->token != '@')
break;
for (p=info->ptr; p->next; p=p->next)
if (p->next->token == ':') break;
if (!p->next) break;
q=p->next;
p->next=0;
if (configt_islocal(info->ptr->next, 0))
{
info->ptr=q->next;
continue;
}
/* foobar is nonlocal, rewrite as foo%bar@foobar */
p=info->ptr;
info->ptr=q->next;
while (q->next)
q=q->next;
q->next=p;
break;
}
/* Rewrite foo@bar@foobar as foo%bar@foobar */
for (p=info->ptr, q=p; p; p=p->next)
if (p->token == ':') q=p->next;
p=0;
while (q)
{
if (q->token == '@' || q->token == '%')
{
if (p) p->token='%';
p=q;
}
q=q->next;
}
if (p) p->token='@';
/* One more time */
if ((p=rfc822check(513, info, 1)) == 0) return (-1);
/* When called from submit (initial receipt of a message),
** either RELAYCLIENT must be set, or this must be one of our domains.
*/
if (!getenv("RELAYCLIENT") && !acceptdomain(p->next))
{
(*info->err_func)(513, "Relaying denied.", info);
return (-1);
}
return (0);
}
static int isindomaindb(char *address, struct dbobj *db)
{
char *p;
int n=8;
for (p=address; *p; p++)
*p=tolower(*p);
p=address;
while (*p && n)
{
if (dbobj_exists(db, p, strlen(p)))
return (1);
if (*p == '.') ++p;
while (*p && *p != '.')
++p;
}
return (0);
}
static int ispercenthack(struct rfc822token *ptr)
{
static char *percenthack=0;
static struct dbobj percenthackdat;
char *p;
if (!percenthack) /* First time */
{
p=config_search("esmtppercentrelay");
percenthack=readfile(p, 0);
free(p);
if (percenthack)
removecomments(percenthack);
else
percenthack="";
dbobj_init(&percenthackdat);
p=config_search("esmtppercentrelay.dat");
dbobj_open(&percenthackdat, p, "R");
free(p);
}
if (*percenthack == 0 && !dbobj_isopen(&percenthackdat))
return (0); /* Don't bother */
p=rfc822_gettok(ptr);
if (config_is_indomain(p, percenthack) ||
(dbobj_isopen(&percenthackdat) &&
isindomaindb(p, &percenthackdat)))
{
free(p);
return (1);
}
free(p);
return (0);
}
/*
** Transform foo%bar@foobar into foo@bar, if foobar is a local domain,
** and bar can be found in percenthack.
*/
static void rwinput(struct rw_info *info, void (*func)(struct rw_info *))
{
struct rfc822token *p, *q, **start, **ptr;
for (start= &info->ptr, p=info->ptr; p; p=p->next)
if (p->token == ':')
start =&p->next;
for (p=0, ptr=start; *ptr; ptr= &(*ptr)->next)
{
if ( (*ptr)->token == '%' )
p= *ptr;
if ( (*ptr)->token == '@' )
break;
}
if (!p || *ptr == 0 || !configt_islocal((*ptr)->next, 0))
{
(*func)(info);
return;
}
q= *ptr;
*ptr=0;
if (ispercenthack(p->next))
p->token='@';
else *ptr=q;
(*func)(info);
}
/* Do the opposite of rwinput */
static void rwoutput(struct rw_info *info, void (*func)(struct rw_info *))
{
struct rfc822token *p, *q, **r;
const char *me;
struct rfc822t *tp;
struct rfc822token at;
if (info->ptr == 0)
{
(*func)(info);
return;
}
for (q=0, p=info->ptr; p; p=p->next)
if (p->token == '@') q=p;
if (q)
{
if (!ispercenthack(q->next))
{
(*func)(info);
return;
}
q->token='%';
}
for (r= &info->ptr; *r; r= &(*r)->next)
;
at.token='@';
at.ptr=0;
at.len=0;
me=config_defaultdomain();
tp=rw_rewrite_tokenize(me);
at.next=tp->tokens;
*r=&at;
(*func)(info);
*r=0;
rfc822t_free(tp);
}
static void rw_esmtp(struct rw_info *info, void (*func)(struct rw_info *))
{
if ((info->mode & RW_SUBMIT) /* From submit process */
&& (info->mode & RW_OUTPUT) == 0)
/* NOT for output rewriting */
{
if (info->mode & RW_ENVSENDER)
{
if (info->ptr &&
(info->ptr->token || info->ptr->len))
/* NULL sender OK */
{
if (rfc822check(517, info, 0) == 0)
return;
}
}
else if (info->mode & RW_ENVRECIPIENT)
{
if (rwrecip(info)) return;
}
}
if (info->mode & RW_OUTPUT)
rwoutput(info, func);
else
rwinput(info, func);
}
static void rw_del_esmtp(struct rw_info *rwi,
void (*nextfunc)(struct rw_info *),
void (*delfunc)(struct rw_info *, const struct rfc822token *,
const struct rfc822token *))
{
struct rfc822token *p;
char *c;
struct rfc822token host, addr;
for (p=rwi->ptr; p; p=p->next)
{
if (p->token == '!')
{
(*nextfunc)(rwi); /* We don't talk UUCP */
return;
}
if (p->token == '@') break;
}
if (!p)
{
(*nextfunc)(rwi);
return;
}
if (configt_islocal(p->next, 0))
{
(*nextfunc)(rwi);
/* Local module should handle it */
return;
}
if (rwi->mode & RW_VERIFY)
{
(*rwi->err_func)(550, "Remote address.", rwi);
return;
}
c=rfc822_gettok(rwi->ptr);
if (!c) clog_msg_errno();
domainlower(c);
host.next=0;
host.token=0;
host.ptr=strchr(c, '@')+1;
host.len=strlen(host.ptr);
addr.next=0;
addr.token=0;
addr.ptr=c;
addr.len=strlen(c);
(*delfunc)(rwi, &host, &addr);
free(c);
}
/************************************************************************/
/* Should we accept mail for this domain? */
/************************************************************************/
static int acceptdomain(const struct rfc822token *t)
{
char *address=rfc822_gettok(t);
int rc;
static const char *acceptdomains=0;
static struct dbobj acceptdomainsdb;
if (!address) clog_msg_errno();
if (!acceptdomains)
{
char *filename=config_search("esmtpacceptmailfor");
char *buf;
buf=readfile(filename, 0);
free(filename);
if (!buf)
acceptdomains=config_me();
else
{
removecomments(buf);
acceptdomains=buf;
}
dbobj_init(&acceptdomainsdb);
filename=config_search("esmtpacceptmailfor.dat");
dbobj_open(&acceptdomainsdb, filename, "R");
free(filename);
}
rc=config_is_indomain(address, acceptdomains);
if (rc == 0 && dbobj_isopen(&acceptdomainsdb))
rc=isindomaindb(address, &acceptdomainsdb);
free(address);
return (rc);
}
