dhcpcd: Fix truncated packets issue (#4180)

Add a patch with the upstream fix for the truncated packets issue.

http://roy.marples.name/projects/dhcpcd/info/3fd740f3ed
This commit is contained in:
Renato Aguiar 2016-05-12 02:30:08 -07:00 committed by Juan RP
parent 94181e3608
commit 4176afdfab
2 changed files with 78 additions and 1 deletions

View File

@ -0,0 +1,77 @@
Index: dhcp.c
==================================================================
--- dhcp.c
+++ dhcp.c
@@ -1082,13 +1082,16 @@
}
*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++;
}
if (ifo->auth.options & DHCPCD_AUTH_SEND && auth_len != 0)
@@ -3134,18 +3137,30 @@
{
logger(ifp->ctx, LOG_WARNING,
"%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: dhcp.h
==================================================================
--- dhcp.h
+++ dhcp.h
@@ -129,13 +129,10 @@
FQDN_NONE = 0x18,
FQDN_PTR = 0x20,
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)
# ifndef __packed
# define __packed __attribute__((__packed__))

View File

@ -1,7 +1,7 @@
# Template file for 'dhcpcd'
pkgname=dhcpcd
version=6.11.0
revision=1
revision=2
lib32disabled=yes
build_style=configure
configure_args="--prefix=/usr --sbindir=/usr/bin --sysconfdir=/etc --rundir=/run"