6.6-stable review patch. If anyone has any objections, please let me know.
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From: Victor Nogueira victor@mojatatu.com
[ Upstream commit 16085e48cb48aeb50a1178dc276747749910b0f2 ]
As a preparation for adding block ID to mirred, separate the part of mirred that redirect/mirrors to a dev into a specific function so that it can be called by blockcast for each dev.
Also improve readability. Eg. rename use_reinsert to dont_clone and skb2 to skb_to_send.
Co-developed-by: Jamal Hadi Salim jhs@mojatatu.com Signed-off-by: Jamal Hadi Salim jhs@mojatatu.com Co-developed-by: Pedro Tammela pctammela@mojatatu.com Signed-off-by: Pedro Tammela pctammela@mojatatu.com Signed-off-by: Victor Nogueira victor@mojatatu.com Signed-off-by: David S. Miller davem@davemloft.net Stable-dep-of: 52f671db1882 ("net/sched: act_mirred: use the backlog for mirred ingress") Signed-off-by: Sasha Levin sashal@kernel.org --- net/sched/act_mirred.c | 129 +++++++++++++++++++++++------------------ 1 file changed, 72 insertions(+), 57 deletions(-)
diff --git a/net/sched/act_mirred.c b/net/sched/act_mirred.c index 0a711c184c29b..6f2544c1e3961 100644 --- a/net/sched/act_mirred.c +++ b/net/sched/act_mirred.c @@ -225,48 +225,26 @@ static int tcf_mirred_forward(bool want_ingress, struct sk_buff *skb) return err; }
-TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, - const struct tc_action *a, - struct tcf_result *res) +static int tcf_mirred_to_dev(struct sk_buff *skb, struct tcf_mirred *m, + struct net_device *dev, + const bool m_mac_header_xmit, int m_eaction, + int retval) { - struct tcf_mirred *m = to_mirred(a); - struct sk_buff *skb2 = skb; - bool m_mac_header_xmit; - struct net_device *dev; - unsigned int nest_level; - int retval, err = 0; - bool use_reinsert; + struct sk_buff *skb_to_send = skb; bool want_ingress; bool is_redirect; bool expects_nh; bool at_ingress; - int m_eaction; + bool dont_clone; int mac_len; bool at_nh; + int err;
- nest_level = __this_cpu_inc_return(mirred_nest_level); - if (unlikely(nest_level > MIRRED_NEST_LIMIT)) { - net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n", - netdev_name(skb->dev)); - __this_cpu_dec(mirred_nest_level); - return TC_ACT_SHOT; - } - - tcf_lastuse_update(&m->tcf_tm); - tcf_action_update_bstats(&m->common, skb); - - m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit); - m_eaction = READ_ONCE(m->tcfm_eaction); - retval = READ_ONCE(m->tcf_action); - dev = rcu_dereference_bh(m->tcfm_dev); - if (unlikely(!dev)) { - pr_notice_once("tc mirred: target device is gone\n"); - goto out; - } - + is_redirect = tcf_mirred_is_act_redirect(m_eaction); if (unlikely(!(dev->flags & IFF_UP)) || !netif_carrier_ok(dev)) { net_notice_ratelimited("tc mirred to Houston: device %s is down\n", dev->name); + err = -ENODEV; goto out; }
@@ -274,61 +252,98 @@ TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, * since we can't easily detect the clsact caller, skip clone only for * ingress - that covers the TC S/W datapath. */ - is_redirect = tcf_mirred_is_act_redirect(m_eaction); at_ingress = skb_at_tc_ingress(skb); - use_reinsert = at_ingress && is_redirect && - tcf_mirred_can_reinsert(retval); - if (!use_reinsert) { - skb2 = skb_clone(skb, GFP_ATOMIC); - if (!skb2) + dont_clone = skb_at_tc_ingress(skb) && is_redirect && + tcf_mirred_can_reinsert(retval); + if (!dont_clone) { + skb_to_send = skb_clone(skb, GFP_ATOMIC); + if (!skb_to_send) { + err = -ENOMEM; goto out; + } }
want_ingress = tcf_mirred_act_wants_ingress(m_eaction);
/* All mirred/redirected skbs should clear previous ct info */ - nf_reset_ct(skb2); + nf_reset_ct(skb_to_send); if (want_ingress && !at_ingress) /* drop dst for egress -> ingress */ - skb_dst_drop(skb2); + skb_dst_drop(skb_to_send);
expects_nh = want_ingress || !m_mac_header_xmit; at_nh = skb->data == skb_network_header(skb); if (at_nh != expects_nh) { - mac_len = skb_at_tc_ingress(skb) ? skb->mac_len : + mac_len = at_ingress ? skb->mac_len : skb_network_offset(skb); if (expects_nh) { /* target device/action expect data at nh */ - skb_pull_rcsum(skb2, mac_len); + skb_pull_rcsum(skb_to_send, mac_len); } else { /* target device/action expect data at mac */ - skb_push_rcsum(skb2, mac_len); + skb_push_rcsum(skb_to_send, mac_len); } }
- skb2->skb_iif = skb->dev->ifindex; - skb2->dev = dev; + skb_to_send->skb_iif = skb->dev->ifindex; + skb_to_send->dev = dev;
- /* mirror is always swallowed */ if (is_redirect) { - skb_set_redirected(skb2, skb2->tc_at_ingress); - - /* let's the caller reinsert the packet, if possible */ - if (use_reinsert) { - err = tcf_mirred_forward(want_ingress, skb); - if (err) - tcf_action_inc_overlimit_qstats(&m->common); - __this_cpu_dec(mirred_nest_level); - return TC_ACT_CONSUMED; - } + if (skb == skb_to_send) + retval = TC_ACT_CONSUMED; + + skb_set_redirected(skb_to_send, skb_to_send->tc_at_ingress); + + err = tcf_mirred_forward(want_ingress, skb_to_send); + } else { + err = tcf_mirred_forward(want_ingress, skb_to_send); }
- err = tcf_mirred_forward(want_ingress, skb2); if (err) { out: tcf_action_inc_overlimit_qstats(&m->common); - if (tcf_mirred_is_act_redirect(m_eaction)) + if (is_redirect) retval = TC_ACT_SHOT; } + + return retval; +} + +TC_INDIRECT_SCOPE int tcf_mirred_act(struct sk_buff *skb, + const struct tc_action *a, + struct tcf_result *res) +{ + struct tcf_mirred *m = to_mirred(a); + int retval = READ_ONCE(m->tcf_action); + unsigned int nest_level; + bool m_mac_header_xmit; + struct net_device *dev; + int m_eaction; + + nest_level = __this_cpu_inc_return(mirred_nest_level); + if (unlikely(nest_level > MIRRED_NEST_LIMIT)) { + net_warn_ratelimited("Packet exceeded mirred recursion limit on dev %s\n", + netdev_name(skb->dev)); + retval = TC_ACT_SHOT; + goto dec_nest_level; + } + + tcf_lastuse_update(&m->tcf_tm); + tcf_action_update_bstats(&m->common, skb); + + dev = rcu_dereference_bh(m->tcfm_dev); + if (unlikely(!dev)) { + pr_notice_once("tc mirred: target device is gone\n"); + tcf_action_inc_overlimit_qstats(&m->common); + goto dec_nest_level; + } + + m_mac_header_xmit = READ_ONCE(m->tcfm_mac_header_xmit); + m_eaction = READ_ONCE(m->tcfm_eaction); + + retval = tcf_mirred_to_dev(skb, m, dev, m_mac_header_xmit, m_eaction, + retval); + +dec_nest_level: __this_cpu_dec(mirred_nest_level);
return retval;