net: icmp: add skb drop reasons to icmp protocol

Replace kfree_skb() used in icmp_rcv() and icmpv6_rcv() with
kfree_skb_reason().

In order to get the reasons of the skb drops after icmp message handle,
we change the return type of 'handler()' in 'struct icmp_control' from
'bool' to 'enum skb_drop_reason'. This may change its original
intention, as 'false' means failure, but 'SKB_NOT_DROPPED_YET' means
success now. Therefore, all 'handler' and the call of them need to be
handled. Following 'handler' functions are involved:

icmp_unreach()
icmp_redirect()
icmp_echo()
icmp_timestamp()
icmp_discard()

And following new drop reasons are added:

SKB_DROP_REASON_ICMP_CSUM
SKB_DROP_REASON_INVALID_PROTO

The reason 'INVALID_PROTO' is introduced for the case that the packet
doesn't follow rfc 1122 and is dropped. This is not a common case, and
I believe we can locate the problem from the data in the packet. For now,
this 'INVALID_PROTO' is used for the icmp broadcasts with wrong types.

Maybe there should be a document file for these reasons. For example,
list all the case that causes the 'UNHANDLED_PROTO' and 'INVALID_PROTO'
drop reason. Therefore, users can locate their problems according to the
document.

Reviewed-by: Hao Peng <flyingpeng@tencent.com>
Reviewed-by: Jiang Biao <benbjiang@tencent.com>
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Menglong Dong
2022-04-07 14:20:52 +08:00
committed by David S. Miller
parent 41a95a00eb
commit b384c95a86
6 changed files with 75 additions and 47 deletions

View File

@@ -76,7 +76,7 @@ int ping_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock,
int ping_common_sendmsg(int family, struct msghdr *msg, size_t len,
void *user_icmph, size_t icmph_len);
int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
bool ping_rcv(struct sk_buff *skb);
enum skb_drop_reason ping_rcv(struct sk_buff *skb);
#ifdef CONFIG_PROC_FS
void *ping_seq_start(struct seq_file *seq, loff_t *pos, sa_family_t family);