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

srcpkgs/dhcpcd/patches/fix-truncated-packets.patch

@@ -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__))
+

srcpkgs/dhcpcd/template

@@ -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"