From ac80287a6af9fc3f3d189d6d1f523889a0a9e1bc Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy Date: Wed, 15 Jun 2022 16:48:42 +0300 Subject: bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie bpf_tcp_gen_syncookie expects the full length of the TCP header (with all options), and bpf_tcp_check_syncookie accepts lengths bigger than sizeof(struct tcphdr). Fix the documentation that says these lengths should be exactly sizeof(struct tcphdr). While at it, fix a typo in the name of struct ipv6hdr. Signed-off-by: Maxim Mikityanskiy Reviewed-by: Tariq Toukan Link: https://lore.kernel.org/r/20220615134847.3753567-2-maximmi@nvidia.com Signed-off-by: Alexei Starovoitov --- tools/include/uapi/linux/bpf.h | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'tools') diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index f4009dbdf62d..f545e39df72a 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3597,10 +3597,11 @@ union bpf_attr { * * *iph* points to the start of the IPv4 or IPv6 header, while * *iph_len* contains **sizeof**\ (**struct iphdr**) or - * **sizeof**\ (**struct ip6hdr**). + * **sizeof**\ (**struct ipv6hdr**). * * *th* points to the start of the TCP header, while *th_len* - * contains **sizeof**\ (**struct tcphdr**). + * contains the length of the TCP header (at least + * **sizeof**\ (**struct tcphdr**)). * Return * 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative * error otherwise. @@ -3783,10 +3784,11 @@ union bpf_attr { * * *iph* points to the start of the IPv4 or IPv6 header, while * *iph_len* contains **sizeof**\ (**struct iphdr**) or - * **sizeof**\ (**struct ip6hdr**). + * **sizeof**\ (**struct ipv6hdr**). * * *th* points to the start of the TCP header, while *th_len* - * contains the length of the TCP header. + * contains the length of the TCP header with options (at least + * **sizeof**\ (**struct tcphdr**)). * Return * On success, lower 32 bits hold the generated SYN cookie in * followed by 16 bits which hold the MSS value for that cookie, -- cgit v1.2.3