From 8071d5c3e30a68d7bb9ca1bbf48b45f64b459a12 Mon Sep 17 00:00:00 2001
From: Quentin Young <qlyoung@cumulusnetworks.com>
Date: Tue, 22 Jan 2019 22:49:58 +0000
Subject: [PATCH] vrrpd: compute VRRPv3 checksum

Correctly compute VRRPv3 checksum. Pseudoheaders are used for both IPv4
and IPv6.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>
---
 vrrpd/vrrp.c        | 12 +++++++++---
 vrrpd/vrrp.h        |  3 +++
 vrrpd/vrrp_packet.c | 24 +++++++++++++++++++-----
 vrrpd/vrrp_packet.h |  4 ++--
 4 files changed, 33 insertions(+), 10 deletions(-)

diff --git a/vrrpd/vrrp.c b/vrrpd/vrrp.c
index 93ede7b88f..fcc1cec51c 100644
--- a/vrrpd/vrrp.c
+++ b/vrrpd/vrrp.c
@@ -327,7 +327,7 @@ static void vrrp_send_advertisement(struct vrrp_router *r)
 
 	list_to_array(r->addrs, (void **)addrs, r->addrs->count);
 
-	pktlen = vrrp_pkt_build(&pkt, r->vr->vrid, r->priority,
+	pktlen = vrrp_pkt_build(&pkt, &r->src, r->vr->vrid, r->priority,
 				r->vr->advertisement_interval, r->addrs->count,
 				(struct ipaddr **)&addrs);
 
@@ -347,8 +347,8 @@ static void vrrp_send_advertisement(struct vrrp_router *r)
 
 	if (sent < 0) {
 		zlog_warn(VRRP_LOGPFX VRRP_LOGPFX_VRID
-			  "Failed to send VRRP Advertisement",
-			  r->vr->vrid);
+			  "Failed to send VRRP Advertisement: %s",
+			  r->vr->vrid, safe_strerror(errno));
 	}
 }
 
@@ -523,6 +523,8 @@ done:
  * router's interface and binds the Tx socket of the VRRP router to that
  * address.
  *
+ * Also sets src field of vrrp_router.
+ *
  * r
  *    VRRP router to operate on
  *
@@ -559,10 +561,14 @@ static int vrrp_bind_to_primary_connected(struct vrrp_router *r)
 
 	switch (r->family) {
 	case AF_INET:
+		r->src.ipa_type = IPADDR_V4;
+		r->src.ipaddr_v4 = c->address->u.prefix4;
 		su.sin.sin_family = AF_INET;
 		su.sin.sin_addr = c->address->u.prefix4;
 		break;
 	case AF_INET6:
+		r->src.ipa_type = IPADDR_V6;
+		r->src.ipaddr_v6 = c->address->u.prefix6;
 		su.sin6.sin6_family = AF_INET6;
 		su.sin6.sin6_scope_id = ifp->ifindex;
 		su.sin6.sin6_addr = c->address->u.prefix6;
diff --git a/vrrpd/vrrp.h b/vrrpd/vrrp.h
index 98948a76fc..f68ff85224 100644
--- a/vrrpd/vrrp.h
+++ b/vrrpd/vrrp.h
@@ -75,6 +75,9 @@ struct vrrp_router {
 	/* macvlan interface */
 	struct interface *mvl_ifp;
 
+	/* Source address for advertisements */
+	struct ipaddr src;
+
 	/* Socket read buffer */
 	uint8_t ibuf[IP_MAXPACKET];
 
diff --git a/vrrpd/vrrp_packet.c b/vrrpd/vrrp_packet.c
index 5010b4701d..8147da68e0 100644
--- a/vrrpd/vrrp_packet.c
+++ b/vrrpd/vrrp_packet.c
@@ -26,6 +26,7 @@
 #include "lib/ipaddr.h"
 #include "lib/memory.h"
 
+#include "vrrp.h"
 #include "vrrp_packet.h"
 
 /* clang-format off */
@@ -49,8 +50,8 @@ const char *vrrp_packet_names[16] = {
 };
 /* clang-format on */
 
-ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, uint8_t vrid, uint8_t prio,
-		       uint16_t max_adver_int, uint8_t numip,
+ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, struct ipaddr *src, uint8_t vrid,
+		       uint8_t prio, uint16_t max_adver_int, uint8_t numip,
 		       struct ipaddr **ips)
 {
 	bool v6 = IS_IPADDR_V6(ips[0]);
@@ -72,11 +73,24 @@ ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, uint8_t vrid, uint8_t prio,
 		memcpy(aptr, &ips[i]->ip.addr, addrsz);
 		aptr += addrsz;
 	}
+
 	(*pkt)->hdr.chksum = 0;
 
-	/* FIXME: v6 checksum */
-	uint16_t chksum = in_cksum(*pkt, pktsize);
-	(*pkt)->hdr.chksum = htons(chksum);
+	if (v6) {
+		struct ipv6_ph ph = {};
+		ph.src = src->ipaddr_v6;
+		inet_pton(AF_INET6, VRRP_MCASTV6_GROUP_STR, &ph.dst);
+		ph.ulpl = htons(pktsize);
+		ph.next_hdr = 112;
+		(*pkt)->hdr.chksum = in_cksum_with_ph6(&ph, *pkt, pktsize);
+	} else {
+		struct ipv4_ph ph = {};
+		ph.src = src->ipaddr_v4;
+		inet_pton(AF_INET, VRRP_MCASTV4_GROUP_STR, &ph.dst);
+		ph.proto = 112;
+		ph.len = htons(pktsize);
+		(*pkt)->hdr.chksum = in_cksum_with_ph4(&ph, *pkt, pktsize);
+	}
 
 	return pktsize;
 }
diff --git a/vrrpd/vrrp_packet.h b/vrrpd/vrrp_packet.h
index 7a4a338dae..3a5b161fb7 100644
--- a/vrrpd/vrrp_packet.h
+++ b/vrrpd/vrrp_packet.h
@@ -115,8 +115,8 @@ struct vrrp_pkt {
  *    array of pointer to either struct in_addr (v6 = false) or struct in6_addr
  *    (v6 = true)
  */
-ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, uint8_t vrid, uint8_t prio,
-		       uint16_t max_adver_int, uint8_t numip,
+ssize_t vrrp_pkt_build(struct vrrp_pkt **pkt, struct ipaddr *src, uint8_t vrid,
+		       uint8_t prio, uint16_t max_adver_int, uint8_t numip,
 		       struct ipaddr **ips);
 
 /*
-- 
2.39.5