tcp: add const qualifiers where possible

Adding const qualifiers to pointers can ease code review, and spot some
bugs. It might allow compiler to optimize code further.

For example, is it legal to temporary write a null cksum into tcphdr
in tcp_md5_hash_header() ? I am afraid a sniffer could catch the
temporary null value...

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index d2fe4e06b472..b767a951d47c 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -141,7 +141,7 @@ tcp_timewait_state_process(struct inet_timewait_sock *tw, struct sk_buff *skb,
                            const struct tcphdr *th)
 {
         struct tcp_options_received tmp_opt;
-        u8 *hash_location;
+        const u8 *hash_location;
         struct tcp_timewait_sock *tcptw = tcp_twsk((struct sock *)tw);
         int paws_reject = 0;
 
@@ -566,7 +566,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
                            struct request_sock **prev)
 {
         struct tcp_options_received tmp_opt;
-        u8 *hash_location;
+        const u8 *hash_location;
         struct sock *child;
         const struct tcphdr *th = tcp_hdr(skb);
         __be32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);