From 4daf841a2ef3b2e987894c8107d309ce2b67c202 Mon Sep 17 00:00:00 2001 From: Menglong Dong Date: Wed, 13 Apr 2022 16:15:59 +0800 Subject: [PATCH] net: ipv6: add skb drop reasons to ip6_rcv_core() Replace kfree_skb() used in ip6_rcv_core() with kfree_skb_reason(). No new drop reasons are added. Seems now we use 'SKB_DROP_REASON_IP_INHDR' for too many case during ipv6 header parse or check, just like what 'IPSTATS_MIB_INHDRERRORS' do. Will it be too general and hard to know what happened? Signed-off-by: Menglong Dong Reviewed-by: Jiang Biao Reviewed-by: Hao Peng Signed-off-by: David S. Miller --- net/ipv6/ip6_input.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c index b4880c7c84eb..1b925ecb26e9 100644 --- a/net/ipv6/ip6_input.c +++ b/net/ipv6/ip6_input.c @@ -145,13 +145,14 @@ static void ip6_list_rcv_finish(struct net *net, struct sock *sk, static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, struct net *net) { + enum skb_drop_reason reason; const struct ipv6hdr *hdr; u32 pkt_len; struct inet6_dev *idev; if (skb->pkt_type == PACKET_OTHERHOST) { dev_core_stats_rx_otherhost_dropped_inc(skb->dev); - kfree_skb(skb); + kfree_skb_reason(skb, SKB_DROP_REASON_OTHERHOST); return NULL; } @@ -161,9 +162,12 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, __IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_IN, skb->len); + SKB_DR_SET(reason, NOT_SPECIFIED); if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL || !idev || unlikely(idev->cnf.disable_ipv6)) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); + if (unlikely(idev->cnf.disable_ipv6)) + SKB_DR_SET(reason, IPV6DISABLED); goto drop; } @@ -187,8 +191,10 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, hdr = ipv6_hdr(skb); - if (hdr->version != 6) + if (hdr->version != 6) { + SKB_DR_SET(reason, UNHANDLED_PROTO); goto err; + } __IP6_ADD_STATS(net, idev, IPSTATS_MIB_NOECTPKTS + @@ -226,8 +232,10 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, if (!ipv6_addr_is_multicast(&hdr->daddr) && (skb->pkt_type == PACKET_BROADCAST || skb->pkt_type == PACKET_MULTICAST) && - idev->cnf.drop_unicast_in_l2_multicast) + idev->cnf.drop_unicast_in_l2_multicast) { + SKB_DR_SET(reason, UNICAST_IN_L2_MULTICAST); goto err; + } /* RFC4291 2.7 * Nodes must not originate a packet to a multicast address whose scope @@ -256,12 +264,11 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, if (pkt_len + sizeof(struct ipv6hdr) > skb->len) { __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS); + SKB_DR_SET(reason, PKT_TOO_SMALL); goto drop; } - if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) { - __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); - goto drop; - } + if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr))) + goto err; hdr = ipv6_hdr(skb); } @@ -282,9 +289,10 @@ static struct sk_buff *ip6_rcv_core(struct sk_buff *skb, struct net_device *dev, return skb; err: __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); + SKB_DR_OR(reason, IP_INHDR); drop: rcu_read_unlock(); - kfree_skb(skb); + kfree_skb_reason(skb, reason); return NULL; }