diff options
Diffstat (limited to 'net/ipv4/syncookies.c')
| -rw-r--r-- | net/ipv4/syncookies.c | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index dc478a0574cb..98b25e5d147b 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -41,7 +41,6 @@ static siphash_aligned_key_t syncookie_secret[2]; * requested/supported by the syn/synack exchange. */ #define TSBITS 6 -#define TSMASK (((__u32)1 << TSBITS) - 1) static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, u32 count, int c) @@ -52,6 +51,14 @@ static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, count, &syncookie_secret[c]); } +/* Convert one nsec 64bit timestamp to ts (ms or usec resolution) */ +static u64 tcp_ns_to_ts(bool usec_ts, u64 val) +{ + if (usec_ts) + return div_u64(val, NSEC_PER_USEC); + + return div_u64(val, NSEC_PER_MSEC); +} /* * when syncookies are in effect and tcp timestamps are enabled we encode @@ -62,27 +69,24 @@ static u32 cookie_hash(__be32 saddr, __be32 daddr, __be16 sport, __be16 dport, */ u64 cookie_init_timestamp(struct request_sock *req, u64 now) { - struct inet_request_sock *ireq; - u32 ts, ts_now = tcp_ns_to_ts(now); + const struct inet_request_sock *ireq = inet_rsk(req); + u64 ts, ts_now = tcp_ns_to_ts(false, now); u32 options = 0; - ireq = inet_rsk(req); - options = ireq->wscale_ok ? ireq->snd_wscale : TS_OPT_WSCALE_MASK; if (ireq->sack_ok) options |= TS_OPT_SACK; if (ireq->ecn_ok) options |= TS_OPT_ECN; - ts = ts_now & ~TSMASK; + ts = (ts_now >> TSBITS) << TSBITS; ts |= options; - if (ts > ts_now) { - ts >>= TSBITS; - ts--; - ts <<= TSBITS; - ts |= options; - } - return (u64)ts * (NSEC_PER_SEC / TCP_TS_HZ); + if (ts > ts_now) + ts -= (1UL << TSBITS); + + if (tcp_rsk(req)->req_usec_ts) + return ts * NSEC_PER_USEC; + return ts * NSEC_PER_MSEC; } @@ -302,6 +306,8 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops, treq->af_specific = af_ops; treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield; + treq->req_usec_ts = -1; + #if IS_ENABLED(CONFIG_MPTCP) treq->is_mptcp = sk_is_mptcp(sk); if (treq->is_mptcp) { @@ -338,6 +344,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) __u8 rcv_wscale; struct flowi4 fl4; u32 tsoff = 0; + int l3index; if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) || !th->ack || th->rst) @@ -399,6 +406,9 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) ireq->ir_iif = inet_request_bound_dev_if(sk, skb); + l3index = l3mdev_master_ifindex_by_index(sock_net(sk), ireq->ir_iif); + tcp_ao_syncookie(sk, skb, treq, AF_INET, l3index); + /* We throwed the options of the initial SYN away, so we hope * the ACK carries the same options again (see RFC1122 4.2.3.8) */ |