Module Name: src
Committed By: prlw1
Date: Thu May 26 09:09:47 UTC 2016
Modified Files:
src/external/bsd/dhcpcd/dist: dhcp.c dhcp.h
Log Message:
Handle truncated DHCP messages, provided only the BOOTP vendor area
is truncated. [3fd740f3ed]
OK from roy@
To generate a diff of this commit:
cvs rdiff -u -r1.41 -r1.42 src/external/bsd/dhcpcd/dist/dhcp.c
cvs rdiff -u -r1.15 -r1.16 src/external/bsd/dhcpcd/dist/dhcp.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/external/bsd/dhcpcd/dist/dhcp.c
diff -u src/external/bsd/dhcpcd/dist/dhcp.c:1.41 src/external/bsd/dhcpcd/dist/dhcp.c:1.42
--- src/external/bsd/dhcpcd/dist/dhcp.c:1.41 Mon May 9 20:28:08 2016
+++ src/external/bsd/dhcpcd/dist/dhcp.c Thu May 26 09:09:47 2016
@@ -1,5 +1,5 @@
#include <sys/cdefs.h>
- __RCSID("$NetBSD: dhcp.c,v 1.41 2016/05/09 20:28:08 martin Exp $");
+ __RCSID("$NetBSD: dhcp.c,v 1.42 2016/05/26 09:09:47 prlw1 Exp $");
/*
* dhcpcd - DHCP client daemon
@@ -1087,9 +1087,12 @@ make_message(struct bootp **bootpm, cons
*p++ = DHO_END;
len = (size_t)(p - (uint8_t *)bootp);
- /* Pad out to the BOOTP minimum message length.
- * Some DHCP servers incorrectly require this. */
- while (len < BOOTP_MESSAGE_LENTH_MIN) {
+ /* Pad out to the BOOTP message length.
+ * Even if we send a DHCP packet with a variable length vendor area,
+ * some servers / relay agents don't like packets smaller than
+ * a BOOTP message which is fine because that's stipulated
+ * in RFC1542 section 2.1. */
+ while (len < sizeof(*bootp)) {
*p++ = DHO_PAD;
len++;
}
@@ -3139,14 +3142,26 @@ dhcp_handlepacket(void *arg)
"%s: server %s is not destination",
ifp->name, inet_ntoa(from));
}
-
+ /*
+ * DHCP has a variable option area rather than a fixed
+ * vendor area.
+ * Because DHCP uses the BOOTP protocol it should
+ * still send BOOTP sized packets to be RFC compliant.
+ * However some servers send a truncated vendor area.
+ * dhcpcd can work fine without the vendor area being sent.
+ */
bytes = get_udp_data(&bootp, buf);
- if (bytes < sizeof(struct bootp)) {
+ if (bytes < offsetof(struct bootp, vend)) {
logger(ifp->ctx, LOG_ERR,
"%s: truncated packet (%zu) from %s",
ifp->name, bytes, inet_ntoa(from));
continue;
}
+ /* But to make our IS_DHCP macro easy, ensure the vendor
+ * area has at least 4 octets. */
+ while (bytes < offsetof(struct bootp, vend) + 4)
+ bootp[bytes++] = '\0';
+
dhcp_handledhcp(ifp, (struct bootp *)bootp, bytes, &from);
if (state->raw_fd == -1)
break;
Index: src/external/bsd/dhcpcd/dist/dhcp.h
diff -u src/external/bsd/dhcpcd/dist/dhcp.h:1.15 src/external/bsd/dhcpcd/dist/dhcp.h:1.16
--- src/external/bsd/dhcpcd/dist/dhcp.h:1.15 Mon May 9 10:15:59 2016
+++ src/external/bsd/dhcpcd/dist/dhcp.h Thu May 26 09:09:47 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: dhcp.h,v 1.15 2016/05/09 10:15:59 roy Exp $ */
+/* $NetBSD: dhcp.h,v 1.16 2016/05/26 09:09:47 prlw1 Exp $ */
/*
* dhcpcd - DHCP client daemon
@@ -133,9 +133,6 @@ enum FQDN {
FQDN_BOTH = 0x31
};
-/* Some crappy DHCP servers require the BOOTP minimum length */
-#define BOOTP_MESSAGE_LENTH_MIN 300
-
/* Don't import common.h as that defines __unused which causes problems
* on some Linux systems which define it as part of a structure */
#if __GNUC__ > 2 || defined(__INTEL_COMPILER)
