* [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs @ 2021-06-25 8:25 wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 1/5] mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join wujianguo106 ` (4 more replies) 0 siblings, 5 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: wujianguo <wujianguo@chinatelecom.cn> v6->v7: - patch4: corret the declaration of mptcp_incoming_options() when CONFIG_MPTCP is not set - patch5: add tag Reported-by: kernel test robot <oliver.sang@intel.com> v5->v6: - patch1: describe the testing tools in the commit log - patch4: add return value to mptcp_incoming_options(), return 0 if a subflow has been reset, else return 1, and drop the packet in tcp_data_queue()/tcp_rcv_state_process() if the return value is 0 - patch5: update selftest case "multiple subflows limited by server", since the expected behavior is changed by patch4 v4->v5: - patch4: add comment v3->v4: - patch1: using seq and sport/dport for hashing, and ignore network headers altogether, as suggest by Florian v2->v3: - patch1: directly use inet6_ehashfn() for IPv6 - patch4: add Fixes tag. v1->v2: - patch1: handle ipv6 sockets/addresses, always use 4-tuple drived hash and never look at skb->hash - patch3: split into 2 patches. - patch4: new added. Jianguo Wu (5): mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join mptcp: remove redundant req destruct in subflow_check_req() mptcp: fix syncookie process if mptcp can not_accept new subflow mptcp: avoid processing packet if a subflow reset selftests: mptcp: fix case multiple subflows limited by server include/net/mptcp.h | 5 +++-- net/ipv4/tcp_input.c | 19 +++++++++++++++---- net/mptcp/options.c | 22 ++++++++++++++-------- net/mptcp/subflow.c | 11 +++-------- net/mptcp/syncookies.c | 16 +++++++++++++++- tools/testing/selftests/net/mptcp/mptcp_join.sh | 2 +- 6 files changed, 51 insertions(+), 24 deletions(-) -- 1.8.3.1 ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH mptcp-net v7 1/5] mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 @ 2021-06-25 8:25 ` wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 2/5] mptcp: remove redundant req destruct in subflow_check_req() wujianguo106 ` (3 subsequent siblings) 4 siblings, 0 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: Jianguo Wu <wujianguo@chinatelecom.cn> I did stress test with wrk(https://github.com/wg/wrk) and webfsd(https://github.com/ourway/webfsd) with the assistance of mptcp-tools(https://github.com/pabeni/mptcp-tools): Server side: ./use_mptcp.sh webfsd -4 -R /tmp/ -p 8099 Client side: ./use_mptcp.sh wrk -c 200 -d 30 -t 4 http://192.168.174.129:8099/ and got the following warning message: [ 55.552626] TCP: request_sock_subflow: Possible SYN flooding on port 8099. Sending cookies. Check SNMP counters. [ 55.553024] ------------[ cut here ]------------ [ 55.553027] WARNING: CPU: 0 PID: 10 at net/core/flow_dissector.c:984 __skb_flow_dissect+0x280/0x1650 ... [ 55.553117] CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.12.0+ #18 [ 55.553121] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 02/27/2020 [ 55.553124] RIP: 0010:__skb_flow_dissect+0x280/0x1650 ... [ 55.553133] RSP: 0018:ffffb79580087770 EFLAGS: 00010246 [ 55.553137] RAX: 0000000000000000 RBX: ffffffff8ddb58e0 RCX: ffffb79580087888 [ 55.553139] RDX: ffffffff8ddb58e0 RSI: ffff8f7e4652b600 RDI: 0000000000000000 [ 55.553141] RBP: ffffb79580087858 R08: 0000000000000000 R09: 0000000000000008 [ 55.553143] R10: 000000008c622965 R11: 00000000d3313a5b R12: ffff8f7e4652b600 [ 55.553146] R13: ffff8f7e465c9062 R14: 0000000000000000 R15: ffffb79580087888 [ 55.553149] FS: 0000000000000000(0000) GS:ffff8f7f75e00000(0000) knlGS:0000000000000000 [ 55.553152] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.553154] CR2: 00007f73d1d19000 CR3: 0000000135e10004 CR4: 00000000003706f0 [ 55.553160] Call Trace: [ 55.553166] ? __sha256_final+0x67/0xd0 [ 55.553173] ? sha256+0x7e/0xa0 [ 55.553177] __skb_get_hash+0x57/0x210 [ 55.553182] subflow_init_req_cookie_join_save+0xac/0xc0 [ 55.553189] subflow_check_req+0x474/0x550 [ 55.553195] ? ip_route_output_key_hash+0x67/0x90 [ 55.553200] ? xfrm_lookup_route+0x1d/0xa0 [ 55.553207] subflow_v4_route_req+0x8e/0xd0 [ 55.553212] tcp_conn_request+0x31e/0xab0 [ 55.553218] ? selinux_socket_sock_rcv_skb+0x116/0x210 [ 55.553224] ? tcp_rcv_state_process+0x179/0x6d0 [ 55.553229] tcp_rcv_state_process+0x179/0x6d0 [ 55.553235] tcp_v4_do_rcv+0xaf/0x220 [ 55.553239] tcp_v4_rcv+0xce4/0xd80 [ 55.553243] ? ip_route_input_rcu+0x246/0x260 [ 55.553248] ip_protocol_deliver_rcu+0x35/0x1b0 [ 55.553253] ip_local_deliver_finish+0x44/0x50 [ 55.553258] ip_local_deliver+0x6c/0x110 [ 55.553262] ? ip_rcv_finish_core.isra.19+0x5a/0x400 [ 55.553267] ip_rcv+0xd1/0xe0 ... After debugging, I found in __skb_flow_dissect(), skb->dev and skb->sk are both NULL, then net is NULL, and trigger WARN_ON_ONCE(!net), actually net is always NULL in this code path, as skb->dev is set to NULL in tcp_v4_rcv(), and skb->sk is never set. Code snippet in __skb_flow_dissect() that trigger warning: 975 if (skb) { 976 if (!net) { 977 if (skb->dev) 978 net = dev_net(skb->dev); 979 else if (skb->sk) 980 net = sock_net(skb->sk); 981 } 982 } 983 984 WARN_ON_ONCE(!net); So, using seq and transport header derived hash. Fixes: 9466a1ccebbe("mptcp: enable JOIN requests even if cookies are in use"). Suggested-by: Paolo Abeni <pabeni@redhat.com> Suggested-by: Florian Westphal <fw@strlen.de> Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> --- net/mptcp/syncookies.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/net/mptcp/syncookies.c b/net/mptcp/syncookies.c index abe0fd0..3712778 100644 --- a/net/mptcp/syncookies.c +++ b/net/mptcp/syncookies.c @@ -37,7 +37,21 @@ struct join_entry { static u32 mptcp_join_entry_hash(struct sk_buff *skb, struct net *net) { - u32 i = skb_get_hash(skb) ^ net_hash_mix(net); + static u32 mptcp_join_hash_secret __read_mostly; + struct tcphdr *th = tcp_hdr(skb); + u32 seq, i; + + net_get_random_once(&mptcp_join_hash_secret, + sizeof(mptcp_join_hash_secret)); + + if (th->syn) + seq = TCP_SKB_CB(skb)->seq; + else + seq = TCP_SKB_CB(skb)->seq - 1; + + i = jhash_3words(seq, net_hash_mix(net), + (__force __u32)th->source << 16 | (__force __u32)th->dest, + mptcp_join_hash_secret); return i % ARRAY_SIZE(join_entries); } -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH mptcp-net v7 2/5] mptcp: remove redundant req destruct in subflow_check_req() 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 1/5] mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join wujianguo106 @ 2021-06-25 8:25 ` wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 3/5] mptcp: fix syncookie process if mptcp can not_accept new subflow wujianguo106 ` (2 subsequent siblings) 4 siblings, 0 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: Jianguo Wu <wujianguo@chinatelecom.cn> In subflow_check_req(), if subflow sport is mismatch, will put msk, destroy token, and destruct req, then return -EPERM, which can be done by subflow_req_destructor() via: tcp_conn_request() |--__reqsk_free() |--subflow_req_destructor() So we should remove these redundant code, otherwise will call tcp_v4_reqsk_destructor() twice, and may double free inet_rsk(req)->ireq_opt. Fixes: 5bc56388c74f ("mptcp: add port number check for MP_JOIN") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> --- net/mptcp/subflow.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 0b5d4a3..3a849fb 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -214,11 +214,6 @@ static int subflow_check_req(struct request_sock *req, ntohs(inet_sk(sk_listener)->inet_sport), ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport)); if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) { - sock_put((struct sock *)subflow_req->msk); - mptcp_token_destroy_request(req); - tcp_request_sock_ops.destructor(req); - subflow_req->msk = NULL; - subflow_req->mp_join = 0; SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_MISMATCHPORTSYNRX); return -EPERM; } -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH mptcp-net v7 3/5] mptcp: fix syncookie process if mptcp can not_accept new subflow 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 1/5] mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 2/5] mptcp: remove redundant req destruct in subflow_check_req() wujianguo106 @ 2021-06-25 8:25 ` wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 5/5] selftests: mptcp: fix case multiple subflows limited by server wujianguo106 4 siblings, 0 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: Jianguo Wu <wujianguo@chinatelecom.cn> Lots of "TCP: tcp_fin: Impossible, sk->sk_state=7" in client side when doing stress testing using wrk and webfsd. There are at least two cases may trigger this warning: 1.mptcp is in syncookie, and server recv MP_JOIN SYN request, in subflow_check_req(), the mptcp_can_accept_new_subflow() return false, so subflow_init_req_cookie_join_save() isn't called, i.e. not store the data present in the MP_JOIN syn request and the random nonce in hash table - join_entries[], but still send synack. When recv 3rd-ack, mptcp_token_join_cookie_init_state() will return false, and 3rd-ack is dropped, then if mptcp conn is closed by client, client will send a DATA_FIN and a MPTCP FIN, the DATA_FIN doesn't have MP_CAPABLE or MP_JOIN, so mptcp_subflow_init_cookie_req() will return 0, and pass the cookie check, MP_JOIN request is fallback to normal TCP. Server will send a TCP FIN if closed, in client side, when process TCP FIN, it will do reset, the code path is: tcp_data_queue()->mptcp_incoming_options() ->check_fully_established()->mptcp_subflow_reset(). mptcp_subflow_reset() will set sock state to TCP_CLOSE, so tcp_fin will hit TCP_CLOSE, and print the warning. 2.mptcp is in syncookie, and server recv 3rd-ack, in mptcp_subflow_init_cookie_req(), mptcp_can_accept_new_subflow() return false, and subflow_req->mp_join is not set to 1, so in subflow_syn_recv_sock() will not reset the MP_JOIN subflow, but fallback to normal TCP, and then the same thing happens when server will send a TCP FIN if closed. For case1, subflow_check_req() return -EPERM, then tcp_conn_request() will drop MP_JOIN SYN. For case2, let subflow_syn_recv_sock() call mptcp_can_accept_new_subflow(), and do fatal fallback, send reset. Fixes: 9466a1ccebbe("mptcp: enable JOIN requests even if cookies are in use") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> --- net/mptcp/subflow.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 3a849fb..f3f1358 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -225,6 +225,8 @@ static int subflow_check_req(struct request_sock *req, if (unlikely(req->syncookie)) { if (mptcp_can_accept_new_subflow(subflow_req->msk)) subflow_init_req_cookie_join_save(subflow_req, skb); + else + return -EPERM; } pr_debug("token=%u, remote_nonce=%u msk=%p", subflow_req->token, @@ -264,9 +266,7 @@ int mptcp_subflow_init_cookie_req(struct request_sock *req, if (!mptcp_token_join_cookie_init_state(subflow_req, skb)) return -EINVAL; - if (mptcp_can_accept_new_subflow(subflow_req->msk)) - subflow_req->mp_join = 1; - + subflow_req->mp_join = 1; subflow_req->ssn_offset = TCP_SKB_CB(skb)->seq - 1; } -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 ` (2 preceding siblings ...) 2021-06-25 8:25 ` [PATCH mptcp-net v7 3/5] mptcp: fix syncookie process if mptcp can not_accept new subflow wujianguo106 @ 2021-06-25 8:25 ` wujianguo106 2021-06-25 8:58 ` Geliang Tang ` (3 more replies) 2021-06-25 8:25 ` [PATCH mptcp-net v7 5/5] selftests: mptcp: fix case multiple subflows limited by server wujianguo106 4 siblings, 4 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: Jianguo Wu <wujianguo@chinatelecom.cn> If check_fully_established() causes a subflow reset, it should not continue to process the packet in tcp_data_queue(). Add a return value to mptcp_incoming_options(), and return 0 if a subflow has been reset, else return 1. Then drop the packet in tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options() return 0. Fixes: d582484726c4 ("mptcp: fix fallback for MP_JOIN subflows") Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> --- include/net/mptcp.h | 5 +++-- net/ipv4/tcp_input.c | 19 +++++++++++++++---- net/mptcp/options.c | 22 ++++++++++++++-------- 3 files changed, 32 insertions(+), 14 deletions(-) diff --git a/include/net/mptcp.h b/include/net/mptcp.h index cb580b0..cbd511c 100644 --- a/include/net/mptcp.h +++ b/include/net/mptcp.h @@ -105,7 +105,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, unsigned int *size, unsigned int remaining, struct mptcp_out_options *opts); -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, struct mptcp_out_options *opts); @@ -227,9 +227,10 @@ static inline bool mptcp_established_options(struct sock *sk, return false; } -static inline void mptcp_incoming_options(struct sock *sk, +static inline int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) { + return 1; } static inline void mptcp_skb_ext_move(struct sk_buff *to, diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7d5e59f..4bacd7d 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -4247,6 +4247,9 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb) { trace_tcp_receive_reset(sk); + /* mptcp can't tell us to ignore reset pkts, + * so just ignore the return value of mptcp_incoming_options(). + */ if (sk_is_mptcp(sk)) mptcp_incoming_options(sk, skb); @@ -4941,8 +4944,13 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) bool fragstolen; int eaten; - if (sk_is_mptcp(sk)) - mptcp_incoming_options(sk, skb); + /* If a subflow has been reset, the packet should not continue + * to be processed, drop the packet. + */ + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) { + __kfree_skb(skb); + return; + } if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { __kfree_skb(skb); @@ -6523,8 +6531,11 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) case TCP_CLOSING: case TCP_LAST_ACK: if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { - if (sk_is_mptcp(sk)) - mptcp_incoming_options(sk, skb); + /* If a subflow has been reset, the packet should not + * continue to be processed, drop the packet. + */ + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) + goto discard; break; } fallthrough; diff --git a/net/mptcp/options.c b/net/mptcp/options.c index b5850af..f4842b5 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -856,7 +856,8 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, struct mptcp_subflow_context *subflow, struct sk_buff *skb, - struct mptcp_options_received *mp_opt) + struct mptcp_options_received *mp_opt, + bool *subflow_is_rst) { /* here we can process OoO, in-window pkts, only in-sequence 4th ack * will make the subflow fully established @@ -938,6 +939,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, return true; reset: + *subflow_is_rst = true; mptcp_subflow_reset(ssk); return false; } @@ -1035,12 +1037,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, return hmac == mp_opt->ahmac; } -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) +/* Return 0 if a subflow has been reset, else return 1 */ +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) { struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); struct mptcp_sock *msk = mptcp_sk(subflow->conn); struct mptcp_options_received mp_opt; struct mptcp_ext *mpext; + bool subflow_is_rst = false; if (__mptcp_check_fallback(msk)) { /* Keep it simple and unconditionally trigger send data cleanup and @@ -1053,12 +1057,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) __mptcp_check_push(subflow->conn, sk); __mptcp_data_acked(subflow->conn); mptcp_data_unlock(subflow->conn); - return; + return 1; } mptcp_get_options(sk, skb, &mp_opt); - if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) - return; + if (!check_fully_established(msk, sk, subflow, skb, &mp_opt, &subflow_is_rst)) + return subflow_is_rst ? 0 : 1; if (mp_opt.fastclose && msk->local_key == mp_opt.rcvr_key) { @@ -1100,7 +1104,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) } if (!mp_opt.dss) - return; + return 1; /* we can't wait for recvmsg() to update the ack_seq, otherwise * monodirectional flows will stuck @@ -1119,12 +1123,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) schedule_work(&msk->work)) sock_hold(subflow->conn); - return; + return 1; } mpext = skb_ext_add(skb, SKB_EXT_MPTCP); if (!mpext) - return; + return 1; memset(mpext, 0, sizeof(*mpext)); @@ -1153,6 +1157,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) if (mpext->csum_reqd) mpext->csum = mp_opt.csum; } + + return 1; } static void mptcp_set_rwin(const struct tcp_sock *tp) -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 @ 2021-06-25 8:58 ` Geliang Tang 2021-06-25 9:07 ` Matthieu Baerts ` (2 subsequent siblings) 3 siblings, 0 replies; 13+ messages in thread From: Geliang Tang @ 2021-06-25 8:58 UTC (permalink / raw) To: Jianguo Wu; +Cc: mptcp, Paolo Abeni, Mat Martineau Hi Jianguo, Thank you for this patchset! <wujianguo106@163.com> 于2021年6月25日周五 下午4:26写道: > > From: Jianguo Wu <wujianguo@chinatelecom.cn> > > If check_fully_established() causes a subflow reset, it should not > continue to process the packet in tcp_data_queue(). > Add a return value to mptcp_incoming_options(), and return 0 if a > subflow has been reset, else return 1. Then drop the packet in > tcp_data_queue()/tcp_rcv_state_process() if mptcp_incoming_options() > return 0. > > Fixes: d582484726c4 ("mptcp: fix fallback for MP_JOIN subflows") > Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> > --- > include/net/mptcp.h | 5 +++-- > net/ipv4/tcp_input.c | 19 +++++++++++++++---- > net/mptcp/options.c | 22 ++++++++++++++-------- > 3 files changed, 32 insertions(+), 14 deletions(-) > > diff --git a/include/net/mptcp.h b/include/net/mptcp.h > index cb580b0..cbd511c 100644 > --- a/include/net/mptcp.h > +++ b/include/net/mptcp.h > @@ -105,7 +105,7 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, > bool mptcp_established_options(struct sock *sk, struct sk_buff *skb, > unsigned int *size, unsigned int remaining, > struct mptcp_out_options *opts); > -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); > +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb); > > void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, > struct mptcp_out_options *opts); > @@ -227,9 +227,10 @@ static inline bool mptcp_established_options(struct sock *sk, > return false; > } > > -static inline void mptcp_incoming_options(struct sock *sk, > +static inline int mptcp_incoming_options(struct sock *sk, > struct sk_buff *skb) > { > + return 1; > } > > static inline void mptcp_skb_ext_move(struct sk_buff *to, > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index 7d5e59f..4bacd7d 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -4247,6 +4247,9 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb) > { > trace_tcp_receive_reset(sk); > > + /* mptcp can't tell us to ignore reset pkts, > + * so just ignore the return value of mptcp_incoming_options(). > + */ > if (sk_is_mptcp(sk)) > mptcp_incoming_options(sk, skb); > > @@ -4941,8 +4944,13 @@ static void tcp_data_queue(struct sock *sk, struct sk_buff *skb) > bool fragstolen; > int eaten; > > - if (sk_is_mptcp(sk)) > - mptcp_incoming_options(sk, skb); > + /* If a subflow has been reset, the packet should not continue > + * to be processed, drop the packet. > + */ > + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) { > + __kfree_skb(skb); > + return; > + } > > if (TCP_SKB_CB(skb)->seq == TCP_SKB_CB(skb)->end_seq) { > __kfree_skb(skb); > @@ -6523,8 +6531,11 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb) > case TCP_CLOSING: > case TCP_LAST_ACK: > if (!before(TCP_SKB_CB(skb)->seq, tp->rcv_nxt)) { > - if (sk_is_mptcp(sk)) > - mptcp_incoming_options(sk, skb); > + /* If a subflow has been reset, the packet should not > + * continue to be processed, drop the packet. > + */ > + if (sk_is_mptcp(sk) && !mptcp_incoming_options(sk, skb)) > + goto discard; > break; > } > fallthrough; > diff --git a/net/mptcp/options.c b/net/mptcp/options.c > index b5850af..f4842b5 100644 > --- a/net/mptcp/options.c > +++ b/net/mptcp/options.c > @@ -856,7 +856,8 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, > static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, > struct mptcp_subflow_context *subflow, > struct sk_buff *skb, > - struct mptcp_options_received *mp_opt) > + struct mptcp_options_received *mp_opt, > + bool *subflow_is_rst) > { > /* here we can process OoO, in-window pkts, only in-sequence 4th ack > * will make the subflow fully established > @@ -938,6 +939,7 @@ static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, > return true; > > reset: > + *subflow_is_rst = true; > mptcp_subflow_reset(ssk); > return false; > } > @@ -1035,12 +1037,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, > return hmac == mp_opt->ahmac; > } > > -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > +/* Return 0 if a subflow has been reset, else return 1 */ How about returning a bool here, return true or return false? -Geliang > +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > { > struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); > struct mptcp_sock *msk = mptcp_sk(subflow->conn); > struct mptcp_options_received mp_opt; > struct mptcp_ext *mpext; > + bool subflow_is_rst = false; > > if (__mptcp_check_fallback(msk)) { > /* Keep it simple and unconditionally trigger send data cleanup and > @@ -1053,12 +1057,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > __mptcp_check_push(subflow->conn, sk); > __mptcp_data_acked(subflow->conn); > mptcp_data_unlock(subflow->conn); > - return; > + return 1; > } > > mptcp_get_options(sk, skb, &mp_opt); > - if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) > - return; > + if (!check_fully_established(msk, sk, subflow, skb, &mp_opt, &subflow_is_rst)) > + return subflow_is_rst ? 0 : 1; > > if (mp_opt.fastclose && > msk->local_key == mp_opt.rcvr_key) { > @@ -1100,7 +1104,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > } > > if (!mp_opt.dss) > - return; > + return 1; > > /* we can't wait for recvmsg() to update the ack_seq, otherwise > * monodirectional flows will stuck > @@ -1119,12 +1123,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > schedule_work(&msk->work)) > sock_hold(subflow->conn); > > - return; > + return 1; > } > > mpext = skb_ext_add(skb, SKB_EXT_MPTCP); > if (!mpext) > - return; > + return 1; > > memset(mpext, 0, sizeof(*mpext)); > > @@ -1153,6 +1157,8 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > if (mpext->csum_reqd) > mpext->csum = mp_opt.csum; > } > + > + return 1; > } > > static void mptcp_set_rwin(const struct tcp_sock *tp) > -- > 1.8.3.1 > > > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 2021-06-25 8:58 ` Geliang Tang @ 2021-06-25 9:07 ` Matthieu Baerts 2021-06-25 9:46 ` Jianguo Wu 2021-06-25 10:38 ` Paolo Abeni 2021-06-25 10:45 ` Paolo Abeni 3 siblings, 1 reply; 13+ messages in thread From: Matthieu Baerts @ 2021-06-25 9:07 UTC (permalink / raw) To: wujianguo106, mptcp; +Cc: pabeni, mathew.j.martineau Hi Jianguo, Thank you for working on that! On 25/06/2021 10:25, wujianguo106@163.com wrote: > From: Jianguo Wu <wujianguo@chinatelecom.cn> > > If check_fully_established() causes a subflow reset, it should not > continue to process the packet in tcp_data_queue(). > Add a return value to mptcp_incoming_options(), and return 0 if a > subflow has been reset, else return 1. A small detail but it looks strange to me to return +1. Maybe clearer to return -1 in case of error or return a boolean? If you decide to return -1, please check for '< 0': if (mptcp_incoming_options(...) < 0) // error: we discard goto discard; and not: if (mptcp_incoming_options(...)) // no error but we discard?? goto discard; (Or replace subflow_is_rst by subflow_is_accepted and return this variable but it might be strange to return that if you don't have a DSS, etc.) But if it is only me who find "strange" to return 0/+1, fine not to change but it looks uncommon and maybe a source of misinterpretation :) Cheers, Matt -- Tessares | Belgium | Hybrid Access Solutions www.tessares.net ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 9:07 ` Matthieu Baerts @ 2021-06-25 9:46 ` Jianguo Wu 2021-06-26 1:07 ` Mat Martineau 0 siblings, 1 reply; 13+ messages in thread From: Jianguo Wu @ 2021-06-25 9:46 UTC (permalink / raw) To: Matthieu Baerts, mptcp; +Cc: pabeni, mathew.j.martineau, Geliang Tang On 2021/6/25 17:07, Matthieu Baerts wrote: > Hi Jianguo, > > Thank you for working on that! > > On 25/06/2021 10:25, wujianguo106@163.com wrote: >> From: Jianguo Wu <wujianguo@chinatelecom.cn> >> >> If check_fully_established() causes a subflow reset, it should not >> continue to process the packet in tcp_data_queue(). >> Add a return value to mptcp_incoming_options(), and return 0 if a >> subflow has been reset, else return 1. > > A small detail but it looks strange to me to return +1. > Maybe clearer to return -1 in case of error or return a boolean? > Hi Mat and Geliang, Based on your comments, I will use boolean type as return value, return false if a subflow has been reset. Thanks for your review! > If you decide to return -1, please check for '< 0': > > if (mptcp_incoming_options(...) < 0) // error: we discard > goto discard; > > and not: > > if (mptcp_incoming_options(...)) // no error but we discard?? > goto discard; > > (Or replace subflow_is_rst by subflow_is_accepted and return this > variable but it might be strange to return that if you don't have a DSS, > etc.) > > But if it is only me who find "strange" to return 0/+1, fine not to > change but it looks uncommon and maybe a source of misinterpretation :) > > Cheers, > Matt > ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 9:46 ` Jianguo Wu @ 2021-06-26 1:07 ` Mat Martineau 0 siblings, 0 replies; 13+ messages in thread From: Mat Martineau @ 2021-06-26 1:07 UTC (permalink / raw) To: Jianguo Wu; +Cc: Matthieu Baerts, mptcp, pabeni, Geliang Tang On Fri, 25 Jun 2021, Jianguo Wu wrote: > > > On 2021/6/25 17:07, Matthieu Baerts wrote: >> Hi Jianguo, >> >> Thank you for working on that! >> >> On 25/06/2021 10:25, wujianguo106@163.com wrote: >>> From: Jianguo Wu <wujianguo@chinatelecom.cn> >>> >>> If check_fully_established() causes a subflow reset, it should not >>> continue to process the packet in tcp_data_queue(). >>> Add a return value to mptcp_incoming_options(), and return 0 if a >>> subflow has been reset, else return 1. >> >> A small detail but it looks strange to me to return +1. >> Maybe clearer to return -1 in case of error or return a boolean? >> > > Hi Mat and Geliang, > > Based on your comments, I will use boolean type as return value, return false if a subflow has been reset. > Thanks for your review! Thanks - I think the 'bool' fits better here than -1/0. -Mat > >> If you decide to return -1, please check for '< 0': >> >> if (mptcp_incoming_options(...) < 0) // error: we discard >> goto discard; >> >> and not: >> >> if (mptcp_incoming_options(...)) // no error but we discard?? >> goto discard; >> >> (Or replace subflow_is_rst by subflow_is_accepted and return this >> variable but it might be strange to return that if you don't have a DSS, >> etc.) >> >> But if it is only me who find "strange" to return 0/+1, fine not to >> change but it looks uncommon and maybe a source of misinterpretation :) >> >> Cheers, >> Matt >> > > -- Mat Martineau Intel ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 2021-06-25 8:58 ` Geliang Tang 2021-06-25 9:07 ` Matthieu Baerts @ 2021-06-25 10:38 ` Paolo Abeni 2021-06-25 10:45 ` Paolo Abeni 3 siblings, 0 replies; 13+ messages in thread From: Paolo Abeni @ 2021-06-25 10:38 UTC (permalink / raw) To: wujianguo106, mptcp; +Cc: mathew.j.martineau On Fri, 2021-06-25 at 16:25 +0800, wujianguo106@163.com wrote: > @@ -1035,12 +1037,14 @@ static bool add_addr_hmac_valid(struct mptcp_sock *msk, > return hmac == mp_opt->ahmac; > } > > -void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > +/* Return 0 if a subflow has been reset, else return 1 */ > +int mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > { > struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk); > struct mptcp_sock *msk = mptcp_sk(subflow->conn); > struct mptcp_options_received mp_opt; > struct mptcp_ext *mpext; > + bool subflow_is_rst = false; Additional small detail: please use the reverse xmas tree order for variables definition. Thanks! /P ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 ` (2 preceding siblings ...) 2021-06-25 10:38 ` Paolo Abeni @ 2021-06-25 10:45 ` Paolo Abeni 2021-06-26 8:59 ` Jianguo Wu 3 siblings, 1 reply; 13+ messages in thread From: Paolo Abeni @ 2021-06-25 10:45 UTC (permalink / raw) To: wujianguo106, mptcp; +Cc: mathew.j.martineau Hi, I'm sorry for the partial feedback in my previous reply. On Fri, 2021-06-25 at 16:25 +0800, wujianguo106@163.com wrote: > @@ -856,7 +856,8 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, > static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, > struct mptcp_subflow_context *subflow, > struct sk_buff *skb, > - struct mptcp_options_received *mp_opt) > + struct mptcp_options_received *mp_opt, > + bool *subflow_is_rst) This additional argument is not needed... [...] > @@ -1053,12 +1057,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) > __mptcp_check_push(subflow->conn, sk); > __mptcp_data_acked(subflow->conn); > mptcp_data_unlock(subflow->conn); > - return; > + return 1; > } > > mptcp_get_options(sk, skb, &mp_opt); > - if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) > - return; > + if (!check_fully_established(msk, sk, subflow, skb, &mp_opt, &subflow_is_rst)) > + return subflow_is_rst ? 0 : 1; ... here you can simply: return sk->sk_state != TCP_CLOSE; plus some comment above alike: """the subflow can be in close state only if check_fully_established() just sent a reset. If so, tell the caller to ignore the current packet""" /P ^ permalink raw reply [flat|nested] 13+ messages in thread
* Re: [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset 2021-06-25 10:45 ` Paolo Abeni @ 2021-06-26 8:59 ` Jianguo Wu 0 siblings, 0 replies; 13+ messages in thread From: Jianguo Wu @ 2021-06-26 8:59 UTC (permalink / raw) To: Paolo Abeni, mptcp; +Cc: mathew.j.martineau Hi Paolo, On 2021/6/25 18:45, Paolo Abeni wrote: > Hi, > > I'm sorry for the partial feedback in my previous reply. > > On Fri, 2021-06-25 at 16:25 +0800, wujianguo106@163.com wrote: >> @@ -856,7 +856,8 @@ bool mptcp_synack_options(const struct request_sock *req, unsigned int *size, >> static bool check_fully_established(struct mptcp_sock *msk, struct sock *ssk, >> struct mptcp_subflow_context *subflow, >> struct sk_buff *skb, >> - struct mptcp_options_received *mp_opt) >> + struct mptcp_options_received *mp_opt, >> + bool *subflow_is_rst) > > This additional argument is not needed... > > [...] >> @@ -1053,12 +1057,12 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) >> __mptcp_check_push(subflow->conn, sk); >> __mptcp_data_acked(subflow->conn); >> mptcp_data_unlock(subflow->conn); >> - return; >> + return 1; >> } >> >> mptcp_get_options(sk, skb, &mp_opt); >> - if (!check_fully_established(msk, sk, subflow, skb, &mp_opt)) >> - return; >> + if (!check_fully_established(msk, sk, subflow, skb, &mp_opt, &subflow_is_rst)) >> + return subflow_is_rst ? 0 : 1; > > > ... here you can simply: > > return sk->sk_state != TCP_CLOSE; > > plus some comment above alike: > > """the subflow can be in close state only if check_fully_established() > just sent a reset. If so, tell the caller to ignore the current > packet""" > Thank you for all your reviews and suggestions!New version coming soon. > /P > ^ permalink raw reply [flat|nested] 13+ messages in thread
* [PATCH mptcp-net v7 5/5] selftests: mptcp: fix case multiple subflows limited by server 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 ` (3 preceding siblings ...) 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 @ 2021-06-25 8:25 ` wujianguo106 4 siblings, 0 replies; 13+ messages in thread From: wujianguo106 @ 2021-06-25 8:25 UTC (permalink / raw) To: mptcp; +Cc: pabeni, mathew.j.martineau From: Jianguo Wu <wujianguo@chinatelecom.cn> After patch "mptcp: fix syncookie process if mptcp can not_accept new subflow", If subflow is limited, MP_JOIN SYN is dropped, and no SYN/ACK will be replied. So in case "multiple subflows limited by server", the expected SYN/ACK number should be 1. Reported-by: kernel test robot <oliver.sang@intel.com> Signed-off-by: Jianguo Wu <wujianguo@chinatelecom.cn> --- tools/testing/selftests/net/mptcp/mptcp_join.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/mptcp/mptcp_join.sh b/tools/testing/selftests/net/mptcp/mptcp_join.sh index 9a191c1..f02f4de 100755 --- a/tools/testing/selftests/net/mptcp/mptcp_join.sh +++ b/tools/testing/selftests/net/mptcp/mptcp_join.sh @@ -1409,7 +1409,7 @@ syncookies_tests() ip netns exec $ns2 ./pm_nl_ctl add 10.0.3.2 flags subflow ip netns exec $ns2 ./pm_nl_ctl add 10.0.2.2 flags subflow run_tests $ns1 $ns2 10.0.1.1 - chk_join_nr "subflows limited by server w cookies" 2 2 1 + chk_join_nr "subflows limited by server w cookies" 2 1 1 # test signal address with cookies reset_with_cookies -- 1.8.3.1 ^ permalink raw reply related [flat|nested] 13+ messages in thread
end of thread, other threads:[~2021-06-26 9:15 UTC | newest] Thread overview: 13+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-06-25 8:25 [PATCH mptcp-net v7 0/5] Fix some mptcp syncookie process bugs wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 1/5] mptcp: fix warning in __skb_flow_dissect() when do syn cookie for subflow join wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 2/5] mptcp: remove redundant req destruct in subflow_check_req() wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 3/5] mptcp: fix syncookie process if mptcp can not_accept new subflow wujianguo106 2021-06-25 8:25 ` [PATCH mptcp-net v7 4/5] mptcp: avoid processing packet if a subflow reset wujianguo106 2021-06-25 8:58 ` Geliang Tang 2021-06-25 9:07 ` Matthieu Baerts 2021-06-25 9:46 ` Jianguo Wu 2021-06-26 1:07 ` Mat Martineau 2021-06-25 10:38 ` Paolo Abeni 2021-06-25 10:45 ` Paolo Abeni 2021-06-26 8:59 ` Jianguo Wu 2021-06-25 8:25 ` [PATCH mptcp-net v7 5/5] selftests: mptcp: fix case multiple subflows limited by server wujianguo106
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