linux/include/net/dropreason.h, branch v6.3

ipv6: icmp6: add SKB_DROP_REASON_IPV6_NDISC_NS_OTHERHOST

2023-02-20T08:54:23Z

Hosts can often receive neighbour discovery messages that are not for them. Use a dedicated drop reason to make clear the packet is dropped for this normal case. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: icmp6: add SKB_DROP_REASON_IPV6_NDISC_BAD_OPTIONS

2023-02-20T08:54:23Z

This is a generic drop reason for any error detected in ndisc_parse_options(). Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

ipv6: icmp6: add drop reason support to ndisc_rcv()

2023-02-14T03:55:32Z

Creates three new drop reasons: SKB_DROP_REASON_IPV6_NDISC_FRAG: invalid frag (suppress_frag_ndisc). SKB_DROP_REASON_IPV6_NDISC_HOP_LIMIT: invalid hop limit. SKB_DROP_REASON_IPV6_NDISC_BAD_CODE: invalid NDISC icmp6 code. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski

net: dropreason: add SKB_DROP_REASON_IPV6_BAD_EXTHDR

2023-02-14T03:55:32Z

This drop reason can be used whenever an IPv6 packet has a malformed extension header. Signed-off-by: Eric Dumazet Reviewed-by: David Ahern Signed-off-by: Jakub Kicinski

tcp: add TCP_MINTTL drop reason

2023-02-03T05:14:50Z

In the unlikely case incoming packets are dropped because of IP_MINTTL / IPV6_MINHOPCOUNT constraints... Signed-off-by: Eric Dumazet Link: https://lore.kernel.org/r/20230201174345.2708943-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: dropreason: add SKB_DROP_REASON_FRAG_TOO_FAR

2022-11-01T03:14:27Z

IPv4 reassembly unit can decide to drop frags based on /proc/sys/net/ipv4/ipfrag_max_dist sysctl. Add a specific drop reason to track this specific and weird case. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: dropreason: add SKB_DROP_REASON_FRAG_REASM_TIMEOUT

2022-11-01T03:14:27Z

Used to track skbs freed after a timeout happened in a reassmbly unit. Passing a @reason argument to inet_frag_rbtree_purge() allows to use correct consumed status for frags that have been successfully re-assembled. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: dropreason: add SKB_DROP_REASON_DUP_FRAG

2022-11-01T03:14:26Z

This is used to track when a duplicate segment received by various reassembly units is dropped. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: dropreason: add SKB_CONSUMED reason

2022-11-01T03:14:26Z

This will allow to simply use in the future: kfree_skb_reason(skb, reason); Instead of repeating sequences like: if (dropped) kfree_skb_reason(skb, reason); else consume_skb(skb); For instance, following patch in the series is adding @reason to skb_release_data() and skb_release_all(), so that we can propagate a meaningful @reason whenever consume_skb()/kfree_skb() have to take care of a potential frag_list. Signed-off-by: Eric Dumazet Signed-off-by: Jakub Kicinski

net: skb: export skb drop reaons to user by TRACE_DEFINE_ENUM

2022-09-07T14:28:08Z

As Eric reported, the 'reason' field is not presented when trace the kfree_skb event by perf: $ perf record -e skb:kfree_skb -a sleep 10 $ perf script ip_defrag 14605 [021] 221.614303: skb:kfree_skb: skbaddr=0xffff9d2851242700 protocol=34525 location=0xffffffffa39346b1 reason: The cause seems to be passing kernel address directly to TP_printk(), which is not right. As the enum 'skb_drop_reason' is not exported to user space through TRACE_DEFINE_ENUM(), perf can't get the drop reason string from the 'reason' field, which is a number. Therefore, we introduce the macro DEFINE_DROP_REASON(), which is used to define the trace enum by TRACE_DEFINE_ENUM(). With the help of DEFINE_DROP_REASON(), now we can remove the auto-generate that we introduced in the commit ec43908dd556 ("net: skb: use auto-generation to convert skb drop reason to string"), and define the string array 'drop_reasons'. Hmmmm...now we come back to the situation that have to maintain drop reasons in both enum skb_drop_reason and DEFINE_DROP_REASON. But they are both in dropreason.h, which makes it easier. After this commit, now the format of kfree_skb is like this: $ cat /tracing/events/skb/kfree_skb/format name: kfree_skb ID: 1524 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1; signed:0; field:int common_pid; offset:4; size:4; signed:1; field:void * skbaddr; offset:8; size:8; signed:0; field:void * location; offset:16; size:8; signed:0; field:unsigned short protocol; offset:24; size:2; signed:0; field:enum skb_drop_reason reason; offset:28; size:4; signed:0; print fmt: "skbaddr=%p protocol=%u location=%p reason: %s", REC->skbaddr, REC->protocol, REC->location, __print_symbolic(REC->reason, { 1, "NOT_SPECIFIED" }, { 2, "NO_SOCKET" } ...... Fixes: ec43908dd556 ("net: skb: use auto-generation to convert skb drop reason to string") Link: https://lore.kernel.org/netdev/CANn89i+bx0ybvE55iMYf5GJM48WwV1HNpdm9Q6t-HaEstqpCSA@mail.gmail.com/ Reported-by: Eric Dumazet Signed-off-by: Menglong Dong Signed-off-by: David S. Miller