| Message ID | 1624609559-6786-5-git-send-email-wujianguo106@163.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | Fix some mptcp syncookie process bugs | expand |
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 > > >
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
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 >
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
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
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
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 >
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)