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-rw-r--r--src/postscreen/postscreen_endpt.c232
1 files changed, 232 insertions, 0 deletions
diff --git a/src/postscreen/postscreen_endpt.c b/src/postscreen/postscreen_endpt.c
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index 0000000..36949e3
--- /dev/null
+++ b/src/postscreen/postscreen_endpt.c
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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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