tcp: Factorise cookie-independent fields initialisation in cookie_v[46]_check().

We will support arbitrary SYN Cookie with BPF, and then some reqsk fields
are initialised in kfunc, and others are done in cookie_v[46]_check().

This patch factorises the common part as cookie_tcp_reqsk_init() and
calls it in cookie_tcp_reqsk_alloc() to minimise the discrepancy between
cookie_v[46]_check().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231129022924.96156-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2023-11-28 18:29:23 -08:00 committed by Jakub Kicinski
parent 7b0f570f87
commit de5626b95e
2 changed files with 37 additions and 45 deletions

View file

@ -285,10 +285,43 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt,
}
EXPORT_SYMBOL(cookie_ecn_ok);
static int cookie_tcp_reqsk_init(struct sock *sk, struct sk_buff *skb,
struct request_sock *req)
{
struct inet_request_sock *ireq = inet_rsk(req);
struct tcp_request_sock *treq = tcp_rsk(req);
const struct tcphdr *th = tcp_hdr(skb);
req->num_retrans = 0;
ireq->ir_num = ntohs(th->dest);
ireq->ir_rmt_port = th->source;
ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
ireq->ir_mark = inet_request_mark(sk, skb);
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
treq->snt_synack = 0;
treq->tfo_listener = false;
treq->txhash = net_tx_rndhash();
treq->rcv_isn = ntohl(th->seq) - 1;
treq->snt_isn = ntohl(th->ack_seq) - 1;
treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
treq->req_usec_ts = false;
#if IS_ENABLED(CONFIG_MPTCP)
treq->is_mptcp = sk_is_mptcp(sk);
if (treq->is_mptcp)
return mptcp_subflow_init_cookie_req(req, sk, skb);
#endif
return 0;
}
struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops,
struct sock *sk, struct sk_buff *skb)
{
struct tcp_request_sock *treq;
struct request_sock *req;
if (sk_is_mptcp(sk))
@ -299,22 +332,10 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struct request_sock_ops *ops,
if (!req)
return NULL;
treq = tcp_rsk(req);
treq->syn_tos = TCP_SKB_CB(skb)->ip_dsfield;
treq->req_usec_ts = false;
#if IS_ENABLED(CONFIG_MPTCP)
treq->is_mptcp = sk_is_mptcp(sk);
if (treq->is_mptcp) {
int err = mptcp_subflow_init_cookie_req(req, sk, skb);
if (err) {
reqsk_free(req);
return NULL;
}
if (cookie_tcp_reqsk_init(sk, skb, req)) {
reqsk_free(req);
return NULL;
}
#endif
return req;
}
@ -376,28 +397,15 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
treq = tcp_rsk(req);
treq->rcv_isn = ntohl(th->seq) - 1;
treq->snt_isn = ntohl(th->ack_seq) - 1;
treq->ts_off = tsoff;
treq->txhash = net_tx_rndhash();
req->mss = mss;
ireq->ir_num = ntohs(th->dest);
ireq->ir_rmt_port = th->source;
sk_rcv_saddr_set(req_to_sk(req), ip_hdr(skb)->daddr);
sk_daddr_set(req_to_sk(req), ip_hdr(skb)->saddr);
ireq->ir_mark = inet_request_mark(sk, skb);
ireq->snd_wscale = tcp_opt.snd_wscale;
ireq->sack_ok = tcp_opt.sack_ok;
ireq->wscale_ok = tcp_opt.wscale_ok;
ireq->tstamp_ok = tcp_opt.saw_tstamp;
req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
treq->snt_synack = 0;
treq->tfo_listener = false;
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
/* 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)
@ -409,8 +417,6 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
tcp_ao_syncookie(sk, skb, req, AF_INET);
req->num_retrans = 0;
/*
* We need to lookup the route here to get at the correct
* window size. We should better make sure that the window size

View file

@ -178,11 +178,8 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
ireq = inet_rsk(req);
treq = tcp_rsk(req);
treq->tfo_listener = false;
req->mss = mss;
ireq->ir_rmt_port = th->source;
ireq->ir_num = ntohs(th->dest);
ireq->ir_v6_rmt_addr = ipv6_hdr(skb)->saddr;
ireq->ir_v6_loc_addr = ipv6_hdr(skb)->daddr;
@ -196,31 +193,20 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
ireq->pktopts = skb;
}
ireq->ir_iif = inet_request_bound_dev_if(sk, skb);
/* So that link locals have meaning */
if (!sk->sk_bound_dev_if &&
ipv6_addr_type(&ireq->ir_v6_rmt_addr) & IPV6_ADDR_LINKLOCAL)
ireq->ir_iif = tcp_v6_iif(skb);
ireq->ir_mark = inet_request_mark(sk, skb);
req->num_retrans = 0;
ireq->snd_wscale = tcp_opt.snd_wscale;
ireq->sack_ok = tcp_opt.sack_ok;
ireq->wscale_ok = tcp_opt.wscale_ok;
ireq->tstamp_ok = tcp_opt.saw_tstamp;
req->ts_recent = tcp_opt.saw_tstamp ? tcp_opt.rcv_tsval : 0;
treq->snt_synack = 0;
treq->rcv_isn = ntohl(th->seq) - 1;
treq->snt_isn = ntohl(th->ack_seq) - 1;
treq->ts_off = tsoff;
treq->txhash = net_tx_rndhash();
tcp_ao_syncookie(sk, skb, req, AF_INET6);
if (IS_ENABLED(CONFIG_SMC))
ireq->smc_ok = 0;
/*
* We need to lookup the dst_entry to get the correct window size.
* This is taken from tcp_v6_syn_recv_sock. Somebody please enlighten