Messages in this thread | | | From | Menglong Dong <> | Date | Thu, 14 Apr 2022 09:20:21 +0800 | Subject | Re: [PATCH net-next 8/9] net: ipv6: add skb drop reasons to ip6_rcv_core() |
| |
On Thu, Apr 14, 2022 at 4:41 AM Eric Dumazet <edumazet@gmail.com> wrote: > > > On 4/13/22 01:15, menglong8.dong@gmail.com wrote: > > From: Menglong Dong <imagedong@tencent.com> > > > > 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 <imagedong@tencent.com> > > Reviewed-by: Jiang Biao <benbjiang@tencent.com> > > Reviewed-by: Hao Peng <flyingpeng@tencent.com> > > --- > > 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)) > > idev can be NULL here (according to surrounding code), and we crash :/
Yeah, you are right :)
Thanks for your fix!
> > > > > + 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; > > } > >
| |