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/*++
/* NAME
/* postscreen_endpt 3
/* SUMMARY
/* look up connection endpoint information
/* SYNOPSIS
/* #include <postscreen.h>
/*
/* void psc_endpt_lookup(smtp_client_stream, lookup_done)
/* VSTREAM *smtp_client_stream;
/* void (*lookup_done)(status, smtp_client_stream,
/* smtp_client_addr, smtp_client_port,
/* smtp_server_addr, smtp_server_port)
/* int status;
/* MAI_HOSTADDR_STR *smtp_client_addr;
/* MAI_SERVPORT_STR *smtp_client_port;
/* MAI_HOSTADDR_STR *smtp_server_addr;
/* MAI_SERVPORT_STR *smtp_server_port;
/* AUXILIARY METHODS
/* void psc_endpt_local_lookup(smtp_client_stream, lookup_done)
/* VSTREAM *smtp_client_stream;
/* void (*lookup_done)(status, smtp_client_stream,
/* smtp_client_addr, smtp_client_port,
/* smtp_server_addr, smtp_server_port)
/* int status;
/* MAI_HOSTADDR_STR *smtp_client_addr;
/* MAI_SERVPORT_STR *smtp_client_port;
/* MAI_HOSTADDR_STR *smtp_server_addr;
/* MAI_SERVPORT_STR *smtp_server_port;
/* DESCRIPTION
/* psc_endpt_lookup() looks up remote and local connection
/* endpoint information, either through local system calls,
/* or through an adapter for an up-stream proxy protocol.
/*
/* The following summarizes what the postscreen(8) server
/* expects from a proxy protocol adapter routine.
/* .IP \(bu
/* Accept the same arguments as psc_endpt_lookup().
/* .IP \(bu
/* Call psc_endpt_local_lookup() to look up connection info
/* when the upstream proxy indicates that the connection is
/* not proxied (e.g., health check probe).
/* .IP \(bu
/* Validate protocol, address and port syntax. Permit only
/* protocols that are configured with the main.cf:inet_protocols
/* setting.
/* .IP \(bu
/* Convert IPv4-in-IPv6 address syntax to IPv4 syntax when
/* both IPv6 and IPv4 support are enabled with main.cf:inet_protocols.
/* .IP \(bu
/* Log a clear warning message that explains why a request
/* fails.
/* .IP \(bu
/* Never talk to the remote SMTP client.
/* .PP
/* Arguments:
/* .IP client_stream
/* A brand-new stream that is connected to the remote client.
/* This argument MUST be passed to psc_endpt_local_lookup()
/* if the up-stream proxy indicates that a connection is not
/* proxied.
/* .IP lookup
/* Call-back routine that reports the result status, address
/* and port information. The result status is -1 in case of
/* error, 0 in case of success. This MUST NOT be called directly
/* if the up-stream proxy indicates that a connection is not
/* proxied; instead this MUST be called indirectly by
/* psc_endpt_local_lookup().
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*--*/
/* System library. */
#include <sys_defs.h>
#include <string.h>
#ifdef STRCASECMP_IN_STRINGS_H
#include <strings.h>
#endif
/* Utility library. */
#include <msg.h>
#include <myaddrinfo.h>
#include <vstream.h>
#include <inet_proto.h>
/* Global library. */
#include <mail_params.h>
#include <haproxy_srvr.h>
/* Application-specific. */
#include <postscreen.h>
#include <postscreen_haproxy.h>
static const INET_PROTO_INFO *proto_info;
/* psc_sockaddr_to_hostaddr - transform endpoint address and port to string */
static int psc_sockaddr_to_hostaddr(struct sockaddr *addr_storage,
SOCKADDR_SIZE addr_storage_len,
MAI_HOSTADDR_STR *addr_buf,
MAI_SERVPORT_STR *port_buf,
int socktype)
{
int aierr;
if ((aierr = sockaddr_to_hostaddr(addr_storage, addr_storage_len,
addr_buf, port_buf, socktype)) == 0
&& strncasecmp("::ffff:", addr_buf->buf, 7) == 0
&& strchr((char *) proto_info->sa_family_list, AF_INET) != 0)
memmove(addr_buf->buf, addr_buf->buf + 7,
sizeof(addr_buf->buf) - 7);
return (aierr);
}
/* psc_endpt_local_lookup - look up local system connection information */
void psc_endpt_local_lookup(VSTREAM *smtp_client_stream,
PSC_ENDPT_LOOKUP_FN lookup_done)
{
struct sockaddr_storage addr_storage;
SOCKADDR_SIZE addr_storage_len = sizeof(addr_storage);
int status;
MAI_HOSTADDR_STR smtp_client_addr;
MAI_SERVPORT_STR smtp_client_port;
MAI_HOSTADDR_STR smtp_server_addr;
MAI_SERVPORT_STR smtp_server_port;
int aierr;
/*
* Look up the remote SMTP client address and port.
*/
if (getpeername(vstream_fileno(smtp_client_stream), (struct sockaddr *)
&addr_storage, &addr_storage_len) < 0) {
msg_warn("getpeername: %m -- dropping this connection");
status = -1;
}
/*
* Convert the remote SMTP client address and port to printable form for
* logging and access control.
*/
else if ((aierr = psc_sockaddr_to_hostaddr(
(struct sockaddr *) &addr_storage,
addr_storage_len, &smtp_client_addr,
&smtp_client_port, SOCK_STREAM)) != 0) {
msg_warn("cannot convert client address/port to string: %s"
" -- dropping this connection",
MAI_STRERROR(aierr));
status = -1;
}
/*
* Look up the local SMTP server address and port.
*/
else if (getsockname(vstream_fileno(smtp_client_stream),
(struct sockaddr *) &addr_storage,
&addr_storage_len) < 0) {
msg_warn("getsockname: %m -- dropping this connection");
status = -1;
}
/*
* Convert the local SMTP server address and port to printable form for
* logging.
*/
else if ((aierr = psc_sockaddr_to_hostaddr(
(struct sockaddr *) &addr_storage,
addr_storage_len, &smtp_server_addr,
&smtp_server_port, SOCK_STREAM)) != 0) {
msg_warn("cannot convert server address/port to string: %s"
" -- dropping this connection",
MAI_STRERROR(aierr));
status = -1;
} else {
status = 0;
}
lookup_done(status, smtp_client_stream,
&smtp_client_addr, &smtp_client_port,
&smtp_server_addr, &smtp_server_port);
}
/*
* Lookup table for available proxy protocols.
*/
typedef struct {
const char *name;
void (*endpt_lookup) (VSTREAM *, PSC_ENDPT_LOOKUP_FN);
} PSC_ENDPT_LOOKUP_INFO;
static const PSC_ENDPT_LOOKUP_INFO psc_endpt_lookup_info[] = {
NOPROXY_PROTO_NAME, psc_endpt_local_lookup,
HAPROXY_PROTO_NAME, psc_endpt_haproxy_lookup,
0,
};
/* psc_endpt_lookup - look up connection endpoint information */
void psc_endpt_lookup(VSTREAM *smtp_client_stream,
PSC_ENDPT_LOOKUP_FN notify)
{
const PSC_ENDPT_LOOKUP_INFO *pp;
if (proto_info == 0)
proto_info = inet_proto_info();
for (pp = psc_endpt_lookup_info; /* see below */ ; pp++) {
if (pp->name == 0)
msg_fatal("unsupported %s value: %s",
VAR_PSC_UPROXY_PROTO, var_psc_uproxy_proto);
if (strcmp(var_psc_uproxy_proto, pp->name) == 0) {
pp->endpt_lookup(smtp_client_stream, notify);
return;
}
}
}
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