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Diffstat (limited to 'net/ipv6/syncookies.c')
-rw-r--r--net/ipv6/syncookies.c142
1 files changed, 79 insertions, 63 deletions
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c
index 5014aa663452..7e007f013ec8 100644
--- a/net/ipv6/syncookies.c
+++ b/net/ipv6/syncookies.c
@@ -16,6 +16,7 @@
#include <net/secure_seq.h>
#include <net/ipv6.h>
#include <net/tcp.h>
+#include <net/tcp_ecn.h>
#define COOKIEBITS 24 /* Upper bits store count */
#define COOKIEMASK (((__u32)1 << COOKIEBITS) - 1)
@@ -114,80 +115,97 @@ __u32 cookie_v6_init_sequence(const struct sk_buff *skb, __u16 *mssp)
return __cookie_v6_init_sequence(iph, th, mssp);
}
-int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th,
- __u32 cookie)
+int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th)
{
+ __u32 cookie = ntohl(th->ack_seq) - 1;
__u32 seq = ntohl(th->seq) - 1;
- __u32 mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr,
- th->source, th->dest, seq);
+ __u32 mssind;
+
+ mssind = check_tcp_syn_cookie(cookie, &iph->saddr, &iph->daddr,
+ th->source, th->dest, seq);
return mssind < ARRAY_SIZE(msstab) ? msstab[mssind] : 0;
}
EXPORT_SYMBOL_GPL(__cookie_v6_check);
-struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
+static struct request_sock *cookie_tcp_check(struct net *net, struct sock *sk,
+ struct sk_buff *skb)
{
struct tcp_options_received tcp_opt;
- struct inet_request_sock *ireq;
- struct tcp_request_sock *treq;
- struct ipv6_pinfo *np = inet6_sk(sk);
- struct tcp_sock *tp = tcp_sk(sk);
- const struct tcphdr *th = tcp_hdr(skb);
- __u32 cookie = ntohl(th->ack_seq) - 1;
- struct sock *ret = sk;
- struct request_sock *req;
- int full_space, mss;
- struct dst_entry *dst;
- __u8 rcv_wscale;
u32 tsoff = 0;
-
- if (!READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_syncookies) ||
- !th->ack || th->rst)
- goto out;
+ int mss;
if (tcp_synq_no_recent_overflow(sk))
goto out;
- mss = __cookie_v6_check(ipv6_hdr(skb), th, cookie);
- if (mss == 0) {
- __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESFAILED);
+ mss = __cookie_v6_check(ipv6_hdr(skb), tcp_hdr(skb));
+ if (!mss) {
+ __NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESFAILED);
goto out;
}
- __NET_INC_STATS(sock_net(sk), LINUX_MIB_SYNCOOKIESRECV);
+ __NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESRECV);
/* check for timestamp cookie support */
memset(&tcp_opt, 0, sizeof(tcp_opt));
- tcp_parse_options(sock_net(sk), skb, &tcp_opt, 0, NULL);
+ tcp_parse_options(net, skb, &tcp_opt, 0, NULL);
if (tcp_opt.saw_tstamp && tcp_opt.rcv_tsecr) {
- tsoff = secure_tcpv6_ts_off(sock_net(sk),
+ tsoff = secure_tcpv6_ts_off(net,
ipv6_hdr(skb)->daddr.s6_addr32,
ipv6_hdr(skb)->saddr.s6_addr32);
tcp_opt.rcv_tsecr -= tsoff;
}
- if (!cookie_timestamp_decode(sock_net(sk), &tcp_opt))
+ if (!cookie_timestamp_decode(net, &tcp_opt))
goto out;
- ret = NULL;
- req = cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops,
- &tcp_request_sock_ipv6_ops, sk, skb);
- if (!req)
+ return cookie_tcp_reqsk_alloc(&tcp6_request_sock_ops, sk, skb,
+ &tcp_opt, mss, tsoff);
+out:
+ return ERR_PTR(-EINVAL);
+}
+
+struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
+{
+ const struct tcphdr *th = tcp_hdr(skb);
+ struct ipv6_pinfo *np = inet6_sk(sk);
+ struct tcp_sock *tp = tcp_sk(sk);
+ struct inet_request_sock *ireq;
+ struct net *net = sock_net(sk);
+ struct request_sock *req;
+ struct dst_entry *dst;
+ struct sock *ret = sk;
+ __u8 rcv_wscale;
+ int full_space;
+ SKB_DR(reason);
+
+ if (!READ_ONCE(net->ipv4.sysctl_tcp_syncookies) ||
+ !th->ack || th->rst)
goto out;
- ireq = inet_rsk(req);
- treq = tcp_rsk(req);
- treq->tfo_listener = false;
+ if (cookie_bpf_ok(skb)) {
+ req = cookie_bpf_check(sk, skb);
+ } else {
+ req = cookie_tcp_check(net, sk, skb);
+ if (IS_ERR(req))
+ goto out;
+ }
+ if (!req) {
+ SKB_DR_SET(reason, NO_SOCKET);
+ goto out_drop;
+ }
- if (security_inet_conn_request(sk, skb, req))
- goto out_free;
+ ireq = inet_rsk(req);
- 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;
+
+ if (security_inet_conn_request(sk, skb, req)) {
+ SKB_DR_SET(reason, SECURITY_HOOK);
+ goto out_free;
+ }
+
if (ipv6_opt_accepted(sk, skb, &TCP_SKB_CB(skb)->header.h6) ||
np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo ||
np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim) {
@@ -195,27 +213,12 @@ 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 = cookie;
- treq->ts_off = 0;
- treq->txhash = net_tx_rndhash();
- if (IS_ENABLED(CONFIG_SMC))
- ireq->smc_ok = 0;
+ tcp_ao_syncookie(sk, skb, req, AF_INET6);
/*
* We need to lookup the dst_entry to get the correct window size.
@@ -234,15 +237,17 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
fl6.flowi6_mark = ireq->ir_mark;
fl6.fl6_dport = ireq->ir_rmt_port;
fl6.fl6_sport = inet_sk(sk)->inet_sport;
- fl6.flowi6_uid = sk->sk_uid;
+ fl6.flowi6_uid = sk_uid(sk);
security_req_classify_flow(req, flowi6_to_flowi_common(&fl6));
- dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p);
- if (IS_ERR(dst))
+ dst = ip6_dst_lookup_flow(net, sk, &fl6, final_p);
+ if (IS_ERR(dst)) {
+ SKB_DR_SET(reason, IP_OUTNOROUTES);
goto out_free;
+ }
}
- req->rsk_window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
+ req->rsk_window_clamp = READ_ONCE(tp->window_clamp) ? :dst_metric(dst, RTAX_WINDOW);
/* limit the window selection if the user enforce a smaller rx buffer */
full_space = tcp_full_space(sk);
if (sk->sk_userlocks & SOCK_RCVBUF_LOCK &&
@@ -254,13 +259,24 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
ireq->wscale_ok, &rcv_wscale,
dst_metric(dst, RTAX_INITRWND));
- ireq->rcv_wscale = rcv_wscale;
- ireq->ecn_ok = cookie_ecn_ok(&tcp_opt, sock_net(sk), dst);
-
- ret = tcp_get_cookie_sock(sk, skb, req, dst, tsoff);
+ /* req->syncookie is set true only if ACK is validated
+ * by BPF kfunc, then, rcv_wscale is already configured.
+ */
+ if (!req->syncookie)
+ ireq->rcv_wscale = rcv_wscale;
+ ireq->ecn_ok &= cookie_ecn_ok(net, dst);
+ tcp_rsk(req)->accecn_ok = ireq->ecn_ok && cookie_accecn_ok(th);
+
+ ret = tcp_get_cookie_sock(sk, skb, req, dst);
+ if (!ret) {
+ SKB_DR_SET(reason, NO_SOCKET);
+ goto out_drop;
+ }
out:
return ret;
out_free:
reqsk_free(req);
+out_drop:
+ sk_skb_reason_drop(sk, skb, reason);
return NULL;
}
generated by cgit (git 2.34.1) at 2025-12-25 06:09:08 +0000