diff options
| author | Dmitry Safonov <dima@arista.com> | 2024-01-04 13:42:39 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-01-04 09:07:04 -0800 |
| commit | 4c8530dc7d7da4abe97d65e8e038ce9852491369 (patch) | |
| tree | e3dc6f61dc3a5d550b81df051d50482bd5ca1fcf | |
| parent | 2e957f9c32c154f8b823caa4f0921e0056c0c253 (diff) | |
net/tcp: Only produce AO/MD5 logs if there are any keys
User won't care about inproper hash options in the TCP header if they
don't use neither TCP-AO nor TCP-MD5. Yet, those logs can add up in
syslog, while not being a real concern to the host admin:
> kernel: TCP: TCP segment has incorrect auth options set for XX.20.239.12.54681->XX.XX.90.103.80 [S]
Keep silent and avoid logging when there aren't any keys in the system.
Side-note: I also defined static_branch_tcp_*() helpers to avoid more
ifdeffery, going to remove more ifdeffery further with their help.
Reported-by: Christian Kujau <lists@nerdbynature.de>
Closes: https://lore.kernel.org/all/f6b59324-1417-566f-a976-ff2402718a8d@nerdbynature.de/
Signed-off-by: Dmitry Safonov <dima@arista.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Fixes: 2717b5adea9e ("net/tcp: Add tcp_hash_fail() ratelimited logs")
Link: https://lore.kernel.org/r/20240104-tcp_hash_fail-logs-v1-1-ff3e1f6f9e72@arista.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/net/tcp.h | 2 | ||||
| -rw-r--r-- | include/net/tcp_ao.h | 26 |
2 files changed, 23 insertions, 5 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index 144ba48bb07b..87f0e6c2e1f2 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1788,8 +1788,6 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk, const struct sock *addr_sk); #ifdef CONFIG_TCP_MD5SIG -#include <linux/jump_label.h> -extern struct static_key_false_deferred tcp_md5_needed; struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk, int l3index, const union tcp_md5_addr *addr, int family, bool any_l3index); diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h index 647781080613..b04afced4cc9 100644 --- a/include/net/tcp_ao.h +++ b/include/net/tcp_ao.h @@ -127,12 +127,35 @@ struct tcp_ao_info { struct rcu_head rcu; }; +#ifdef CONFIG_TCP_MD5SIG +#include <linux/jump_label.h> +extern struct static_key_false_deferred tcp_md5_needed; +#define static_branch_tcp_md5() static_branch_unlikely(&tcp_md5_needed.key) +#else +#define static_branch_tcp_md5() false +#endif +#ifdef CONFIG_TCP_AO +/* TCP-AO structures and functions */ +#include <linux/jump_label.h> +extern struct static_key_false_deferred tcp_ao_needed; +#define static_branch_tcp_ao() static_branch_unlikely(&tcp_ao_needed.key) +#else +#define static_branch_tcp_ao() false +#endif + +static inline bool tcp_hash_should_produce_warnings(void) +{ + return static_branch_tcp_md5() || static_branch_tcp_ao(); +} + #define tcp_hash_fail(msg, family, skb, fmt, ...) \ do { \ const struct tcphdr *th = tcp_hdr(skb); \ char hdr_flags[6]; \ char *f = hdr_flags; \ \ + if (!tcp_hash_should_produce_warnings()) \ + break; \ if (th->fin) \ *f++ = 'F'; \ if (th->syn) \ @@ -159,9 +182,6 @@ do { \ #ifdef CONFIG_TCP_AO /* TCP-AO structures and functions */ -#include <linux/jump_label.h> -extern struct static_key_false_deferred tcp_ao_needed; - struct tcp4_ao_context { __be32 saddr; __be32 daddr; |