From 9c5eee0afca09cbde6bd00f77876754aaa552970 Mon Sep 17 00:00:00 2001 From: Boris Sukholitko Date: Tue, 1 Jun 2021 15:30:50 +0300 Subject: net/sched: act_vlan: Fix modify to allow 0 Currently vlan modification action checks existence of vlan priority by comparing it to 0. Therefore it is impossible to modify existing vlan tag to have priority 0. For example, the following tc command will change the vlan id but will not affect vlan priority: tc filter add dev eth1 ingress matchall action vlan modify id 300 \ priority 0 pipe mirred egress redirect dev eth2 The incoming packet on eth1: ethertype 802.1Q (0x8100), vlan 200, p 4, ethertype IPv4 will be changed to: ethertype 802.1Q (0x8100), vlan 300, p 4, ethertype IPv4 although the user has intended to have p == 0. The fix is to add tcfv_push_prio_exists flag to struct tcf_vlan_params and rely on it when deciding to set the priority. Fixes: 45a497f2d149a4a8061c (net/sched: act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action) Signed-off-by: Boris Sukholitko Signed-off-by: David S. Miller --- net/sched/act_vlan.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'net/sched/act_vlan.c') diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c index 1cac3c6fbb49..a108469c664f 100644 --- a/net/sched/act_vlan.c +++ b/net/sched/act_vlan.c @@ -70,7 +70,7 @@ static int tcf_vlan_act(struct sk_buff *skb, const struct tc_action *a, /* replace the vid */ tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid; /* replace prio bits, if tcfv_push_prio specified */ - if (p->tcfv_push_prio) { + if (p->tcfv_push_prio_exists) { tci &= ~VLAN_PRIO_MASK; tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT; } @@ -121,6 +121,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, struct tc_action_net *tn = net_generic(net, vlan_net_id); struct nlattr *tb[TCA_VLAN_MAX + 1]; struct tcf_chain *goto_ch = NULL; + bool push_prio_exists = false; struct tcf_vlan_params *p; struct tc_vlan *parm; struct tcf_vlan *v; @@ -189,7 +190,8 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, push_proto = htons(ETH_P_8021Q); } - if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY]) + push_prio_exists = !!tb[TCA_VLAN_PUSH_VLAN_PRIORITY]; + if (push_prio_exists) push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]); break; case TCA_VLAN_ACT_POP_ETH: @@ -241,6 +243,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, p->tcfv_action = action; p->tcfv_push_vid = push_vid; p->tcfv_push_prio = push_prio; + p->tcfv_push_prio_exists = push_prio_exists || action == TCA_VLAN_ACT_PUSH; p->tcfv_push_proto = push_proto; if (action == TCA_VLAN_ACT_PUSH_ETH) { -- cgit v1.2.3