From 7425627b2b2cd671d5bf6541ce50f7cba8a76ad6 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Mon, 6 Nov 2023 14:14:16 -0700 Subject: [PATCH] tcp: Fix -Wc23-extensions in tcp_options_write() Clang warns (or errors with CONFIG_WERROR=y) when CONFIG_TCP_AO is set: net/ipv4/tcp_output.c:663:2: error: label at end of compound statement is a C23 extension [-Werror,-Wc23-extensions] 663 | } | ^ 1 error generated. On earlier releases (such as clang-11, the current minimum supported version for building the kernel) that do not support C23, this was a hard error unconditionally: net/ipv4/tcp_output.c:663:2: error: expected statement } ^ 1 error generated. While adding a semicolon after the label would resolve this, it is more in line with the kernel as a whole to refactor this block into a standalone function, which means the goto a label construct can just be replaced with a return statement. Do so to resolve the warning. Closes: https://github.com/ClangBuiltLinux/linux/issues/1953 Fixes: 1e03d32bea8e ("net/tcp: Add TCP-AO sign to outgoing packets") Signed-off-by: Nathan Chancellor Reviewed-by: Dmitry Safonov Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/tcp_output.c | 70 ++++++++++++++++++++++++------------------- 1 file changed, 39 insertions(+), 31 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 0d8dd5b7e2e5e..eb13a55d660c2 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -601,6 +601,44 @@ static void bpf_skops_write_hdr_opt(struct sock *sk, struct sk_buff *skb, } #endif +static __be32 *process_tcp_ao_options(struct tcp_sock *tp, + const struct tcp_request_sock *tcprsk, + struct tcp_out_options *opts, + struct tcp_key *key, __be32 *ptr) +{ +#ifdef CONFIG_TCP_AO + u8 maclen = tcp_ao_maclen(key->ao_key); + + if (tcprsk) { + u8 aolen = maclen + sizeof(struct tcp_ao_hdr); + + *ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) | + (tcprsk->ao_keyid << 8) | + (tcprsk->ao_rcv_next)); + } else { + struct tcp_ao_key *rnext_key; + struct tcp_ao_info *ao_info; + + ao_info = rcu_dereference_check(tp->ao_info, + lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk)); + rnext_key = READ_ONCE(ao_info->rnext_key); + if (WARN_ON_ONCE(!rnext_key)) + return ptr; + *ptr++ = htonl((TCPOPT_AO << 24) | + (tcp_ao_len(key->ao_key) << 16) | + (key->ao_key->sndid << 8) | + (rnext_key->rcvid)); + } + opts->hash_location = (__u8 *)ptr; + ptr += maclen / sizeof(*ptr); + if (unlikely(maclen % sizeof(*ptr))) { + memset(ptr, TCPOPT_NOP, sizeof(*ptr)); + ptr++; + } +#endif + return ptr; +} + /* Write previously computed TCP options to the packet. * * Beware: Something in the Internet is very sensitive to the ordering of @@ -629,37 +667,7 @@ static void tcp_options_write(struct tcphdr *th, struct tcp_sock *tp, opts->hash_location = (__u8 *)ptr; ptr += 4; } else if (tcp_key_is_ao(key)) { -#ifdef CONFIG_TCP_AO - u8 maclen = tcp_ao_maclen(key->ao_key); - - if (tcprsk) { - u8 aolen = maclen + sizeof(struct tcp_ao_hdr); - - *ptr++ = htonl((TCPOPT_AO << 24) | (aolen << 16) | - (tcprsk->ao_keyid << 8) | - (tcprsk->ao_rcv_next)); - } else { - struct tcp_ao_key *rnext_key; - struct tcp_ao_info *ao_info; - - ao_info = rcu_dereference_check(tp->ao_info, - lockdep_sock_is_held(&tp->inet_conn.icsk_inet.sk)); - rnext_key = READ_ONCE(ao_info->rnext_key); - if (WARN_ON_ONCE(!rnext_key)) - goto out_ao; - *ptr++ = htonl((TCPOPT_AO << 24) | - (tcp_ao_len(key->ao_key) << 16) | - (key->ao_key->sndid << 8) | - (rnext_key->rcvid)); - } - opts->hash_location = (__u8 *)ptr; - ptr += maclen / sizeof(*ptr); - if (unlikely(maclen % sizeof(*ptr))) { - memset(ptr, TCPOPT_NOP, sizeof(*ptr)); - ptr++; - } -out_ao: -#endif + ptr = process_tcp_ao_options(tp, tcprsk, opts, key, ptr); } if (unlikely(opts->mss)) { *ptr++ = htonl((TCPOPT_MSS << 24) |