From 50d1b124825f1900937b5fc9a9075890bfd3c2c3 Mon Sep 17 00:00:00 2001
From: Timothy Redaelli <tredaelli@redhat.com>
Date: Thu, 9 Feb 2017 18:55:28 +0100
Subject: [PATCH] ipaddress: Simplify vf_info parsing

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1264149
Upstream Status: iproute2.git commit ff9463e
Conflicts: Context changes due to missing commit 56e9f0a

commit ff9463e048a55d1262869ef6f6897c44c11fe094
Author: Phil Sutter <phil@nwl.cc>
Date:   Tue Nov 8 22:29:11 2016 +0100

    ipaddress: Simplify vf_info parsing

    Commit 7b8179c780a1a ("iproute2: Add new command to ip link to
    enable/disable VF spoof check") tried to add support for
    IFLA_VF_SPOOFCHK in a backwards-compatible manner, but aparently overdid
    it: parse_rtattr_nested() handles missing attributes perfectly fine in
    that it will leave the relevant field unassigned so calling code can
    just compare against NULL. There is no need to layback from the previous
    (IFLA_VF_TX_RATE) attribute to the next to check if IFLA_VF_SPOOFCHK is
    present or not. To the contrary, it establishes a potentially incorrect
    assumption of these two attributes directly following each other which
    may not be the case (although up to now, kernel aligns them this way).

    This patch cleans up the code to adhere to the common way of checking
    for attribute existence. It has been tested to return correct results
    regardless of whether the kernel exports IFLA_VF_SPOOFCHK or not.

    Signed-off-by: Phil Sutter <phil@nwl.cc>
    Reviewed-by: Greg Rose <grose@lightfleet.com>

Signed-off-by: Timothy Redaelli <tredaelli@redhat.com>
---
 ip/ipaddress.c | 44 ++++++++++----------------------------------
 1 file changed, 10 insertions(+), 34 deletions(-)

diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index 62a25bc..c8ec779 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -291,10 +291,7 @@ static void print_vfinfo(FILE *fp, struct rtattr *vfinfo)
 	struct ifla_vf_mac *vf_mac;
 	struct ifla_vf_vlan *vf_vlan;
 	struct ifla_vf_tx_rate *vf_tx_rate;
-	struct ifla_vf_spoofchk *vf_spoofchk;
-	struct ifla_vf_link_state *vf_linkstate;
 	struct rtattr *vf[IFLA_VF_MAX + 1] = {};
-	struct rtattr *tmp;
 	SPRINT_BUF(b1);
 
 	if (vfinfo->rta_type != IFLA_VF_INFO) {
@@ -308,31 +305,6 @@ static void print_vfinfo(FILE *fp, struct rtattr *vfinfo)
 	vf_vlan = RTA_DATA(vf[IFLA_VF_VLAN]);
 	vf_tx_rate = RTA_DATA(vf[IFLA_VF_TX_RATE]);
 
-	/* Check if the spoof checking vf info type is supported by
-	 * this kernel.
-	 */
-	tmp = (struct rtattr *)((char *)vf[IFLA_VF_TX_RATE] +
-			vf[IFLA_VF_TX_RATE]->rta_len);
-
-	if (tmp->rta_type != IFLA_VF_SPOOFCHK)
-		vf_spoofchk = NULL;
-	else
-		vf_spoofchk = RTA_DATA(vf[IFLA_VF_SPOOFCHK]);
-
-	if (vf_spoofchk) {
-		/* Check if the link state vf info type is supported by
-		 * this kernel.
-		 */
-		tmp = (struct rtattr *)((char *)vf[IFLA_VF_SPOOFCHK] +
-				vf[IFLA_VF_SPOOFCHK]->rta_len);
-
-		if (tmp->rta_type != IFLA_VF_LINK_STATE)
-			vf_linkstate = NULL;
-		else
-			vf_linkstate = RTA_DATA(vf[IFLA_VF_LINK_STATE]);
-	} else
-		vf_linkstate = NULL;
-
 	fprintf(fp, "%s    vf %d MAC %s", _SL_, vf_mac->vf,
 		ll_addr_n2a((unsigned char *)&vf_mac->mac,
 		ETH_ALEN, 0, b1, sizeof(b1)));
@@ -351,14 +323,18 @@ static void print_vfinfo(FILE *fp, struct rtattr *vfinfo)
 		if (vf_rate->min_tx_rate)
 			fprintf(fp, ", min_tx_rate %dMbps", vf_rate->min_tx_rate);
 	}
+	if (vf[IFLA_VF_SPOOFCHK]) {
+		struct ifla_vf_spoofchk *vf_spoofchk =
+			RTA_DATA(vf[IFLA_VF_SPOOFCHK]);
 
-	if (vf_spoofchk && vf_spoofchk->setting != -1) {
-		if (vf_spoofchk->setting)
-			fprintf(fp, ", spoof checking on");
-		else
-			fprintf(fp, ", spoof checking off");
+		if (vf_spoofchk->setting != -1)
+			fprintf(fp, ", spoof checking %s",
+				vf_spoofchk->setting ? "on" : "off");
 	}
-	if (vf_linkstate) {
+	if (vf[IFLA_VF_LINK_STATE]) {
+		struct ifla_vf_link_state *vf_linkstate =
+			RTA_DATA(vf[IFLA_VF_LINK_STATE]);
+
 		if (vf_linkstate->link_state == IFLA_VF_LINK_STATE_AUTO)
 			fprintf(fp, ", link-state auto");
 		else if (vf_linkstate->link_state == IFLA_VF_LINK_STATE_ENABLE)
-- 
1.8.3.1