hollalinux
/
linux-sg2042
mirror of https://github.com/sophgo/linux-riscv.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

net: Update window_clamp if SOCK_RCVBUF is set 

When net.ipv4.tcp_syncookies=1 and syn flood is happened,
cookie_v4_check or cookie_v6_check tries to redo what
tcp_v4_send_synack or tcp_v6_send_synack did,
rsk_window_clamp will be changed if SOCK_RCVBUF is set,
which will make rcv_wscale is different, the client
still operates with initial window scale and can overshot
granted window, the client use the initial scale but local
server use new scale to advertise window value, and session
work abnormally.

Fixes: e88c64f0a4 ("tcp: allow effective reduction of TCP's rcv-buffer via setsockopt")
Signed-off-by: Mao Wenan <wenan.mao@linux.alibaba.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/1604967391-123737-1-git-send-email-wenan.mao@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Mao Wenan 2020-11-10 08:16:31 +08:00 committed by Jakub Kicinski
parent f3037c5a31
commit 909172a149
2 changed files with 15 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
net/ipv4/syncookies.c
View File

@ -331,7 +331,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
__u32 cookie = ntohl(th->ack_seq) - 1; __u32 cookie = ntohl(th->ack_seq) - 1;
struct sock *ret = sk; struct sock *ret = sk;
struct request_sock *req; struct request_sock *req;
int mss; int full_space, mss;
struct rtable *rt; struct rtable *rt;
__u8 rcv_wscale; __u8 rcv_wscale;
struct flowi4 fl4; struct flowi4 fl4;
@ -427,8 +427,13 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
/* Try to redo what tcp_v4_send_synack did. */ /* Try to redo what tcp_v4_send_synack did. */
req->rsk_window_clamp = tp->window_clamp ? :dst_metric(&rt->dst, RTAX_WINDOW); req->rsk_window_clamp = tp->window_clamp ? :dst_metric(&rt->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 &&
(req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0))
req->rsk_window_clamp = full_space;
tcp_select_initial_window(sk, tcp_full_space(sk), req->mss, tcp_select_initial_window(sk, full_space, req->mss,
&req->rsk_rcv_wnd, &req->rsk_window_clamp, &req->rsk_rcv_wnd, &req->rsk_window_clamp,
ireq->wscale_ok, &rcv_wscale, ireq->wscale_ok, &rcv_wscale,
dst_metric(&rt->dst, RTAX_INITRWND)); dst_metric(&rt->dst, RTAX_INITRWND));

10
net/ipv6/syncookies.c
View File

@ -136,7 +136,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
__u32 cookie = ntohl(th->ack_seq) - 1; __u32 cookie = ntohl(th->ack_seq) - 1;
struct sock *ret = sk; struct sock *ret = sk;
struct request_sock *req; struct request_sock *req;
int mss; int full_space, mss;
struct dst_entry *dst; struct dst_entry *dst;
__u8 rcv_wscale; __u8 rcv_wscale;
u32 tsoff = 0; u32 tsoff = 0;
@ -241,7 +241,13 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb)
} }
req->rsk_window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW); req->rsk_window_clamp = tp->window_clamp ? :dst_metric(dst, RTAX_WINDOW);
tcp_select_initial_window(sk, tcp_full_space(sk), req->mss, /* 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 &&
(req->rsk_window_clamp > full_space || req->rsk_window_clamp == 0))
req->rsk_window_clamp = full_space;
tcp_select_initial_window(sk, full_space, req->mss,
&req->rsk_rcv_wnd, &req->rsk_window_clamp, &req->rsk_rcv_wnd, &req->rsk_window_clamp,
ireq->wscale_ok, &rcv_wscale, ireq->wscale_ok, &rcv_wscale,
dst_metric(dst, RTAX_INITRWND)); dst_metric(dst, RTAX_INITRWND));