From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from chinatelecom.cn (prt-mail.chinatelecom.cn [42.123.76.227]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4BAC770 for ; Mon, 12 Jul 2021 01:52:02 +0000 (UTC) HMM_SOURCE_IP:172.18.0.48:34800.308689807 HMM_ATTACHE_NUM:0000 HMM_SOURCE_TYPE:SMTP Received: from clientip-36.111.140.26?logid-a488bbb53f0a488db05dbeb1a1df1460 (unknown [172.18.0.48]) by chinatelecom.cn (HERMES) with SMTP id CE48A28018C; Mon, 12 Jul 2021 09:34:26 +0800 (CST) X-189-SAVE-TO-SEND: liyonglong@chinatelecom.cn Received: from ([172.18.0.48]) by app0024 with ESMTP id a488bbb53f0a488db05dbeb1a1df1460 for mptcp@lists.linux.dev; Mon Jul 12 09:34:25 2021 X-Transaction-ID: a488bbb53f0a488db05dbeb1a1df1460 X-filter-score: X-Real-From: liyonglong@chinatelecom.cn X-Receive-IP: 172.18.0.48 X-MEDUSA-Status: 0 Sender: liyonglong@chinatelecom.cn Subject: Re: [MPTCP][PATCH mptcp-next] Squash to "mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal" To: Geliang Tang , mptcp@lists.linux.dev References: <9365b79b245b8a87af18ca458c67820d47de2515.1626016228.git.geliangtang@gmail.com> <80fa33a249c2ecc7edd9d0047dd84f163307cee7.1626016292.git.geliangtang@gmail.com> From: Yonglong Li Message-ID: <347f6214-cc6b-2af2-c1e7-d9ac7f77f87e@chinatelecom.cn> Date: Mon, 12 Jul 2021 09:34:16 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <80fa33a249c2ecc7edd9d0047dd84f163307cee7.1626016292.git.geliangtang@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit On 2021/7/11 23:15, Geliang Tang wrote: > I think there're still some issues in v8: > > The remaining value is incorrect since "remaining += opt_size;" in the > "drop other suboptions" checks has been called twice in > mptcp_pm_add_addr_signal and mptcp_established_options_add_addr. > I think "remaining" in mptcp_pm_add_addr_signal does not touch "remaining" in mptcp_established_options_add_addr. > opts->local and opts->remote in mptcp_pm_add_addr_signal need be > populate after the length chech, not before the check.] > > The squash-to patch keeped the more orignal code unchanged, and just do > the least, necessary modifications. > Agree opts->local and opts->remote should be asigned after the length check. But if keep the length check out of mptcp_pm_add_addr_signal (out of pm lock ) as orignal code, there is a race that: ==> a add addr event (pm.addr_signal == MPTCP_ADD_ADDR_SIGNAL) ==> call mptcp_pm_add_addr_signal ==> a echo add addr event trigger (pm.addr_signal == MPTCP_ADD_ADDR_ECHO|MPTCP_ADD_ADDR_SIGNAL) ==> at this time opts->remote is empty and the length is incorrect. So I think the orignal code is incorrect. WDYT? > Drop the "drop other suboptions" check in mptcp_pm_add_addr_signal. > > Change arguments of mptcp_pm_add_addr_signal. > > Keep mptcp_add_addr_len unchanged. > > Signed-off-by: Geliang Tang > --- > net/mptcp/options.c | 35 +++++++++++++++++------------------ > net/mptcp/pm.c | 23 +++++++++-------------- > net/mptcp/protocol.h | 27 +++++++++------------------ > 3 files changed, 35 insertions(+), 50 deletions(-) > > diff --git a/net/mptcp/options.c b/net/mptcp/options.c > index 5c0ad9b90866..93ad7b134f74 100644 > --- a/net/mptcp/options.c > +++ b/net/mptcp/options.c > @@ -663,16 +663,14 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * > struct mptcp_sock *msk = mptcp_sk(subflow->conn); > bool drop_other_suboptions = false; > unsigned int opt_size = *size; > - u8 add_addr; > + bool echo; > + bool port; > + u8 family; > int len; > > - if (!mptcp_pm_should_add_signal(msk) || > - !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, opts, &add_addr)) > - return false; > - > - if (((add_addr & BIT(MPTCP_ADD_ADDR_ECHO)) || > - ((add_addr & BIT(MPTCP_ADD_ADDR_SIGNAL)) && > - (opts->local.family == AF_INET6 || opts->local.port))) && > + if ((mptcp_pm_should_add_signal_echo(msk) || > + (mptcp_pm_should_add_signal_addr(msk) && > + (msk->pm.local.family == AF_INET6 || msk->pm.local.port))) && > skb && skb_is_tcp_pure_ack(skb)) { > pr_debug("drop other suboptions"); > opts->suboptions = 0; > @@ -682,7 +680,12 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * > drop_other_suboptions = true; > } > > - len = mptcp_add_addr_len(opts, add_addr); > + if (!mptcp_pm_should_add_signal(msk) || > + !mptcp_pm_add_addr_signal(msk, remaining, &opts->local, &opts->remote, &echo, &port)) > + return false; > + > + family = echo ? opts->remote.family : opts->local.family; > + len = mptcp_add_addr_len(family, echo, port); > if (remaining < len) > return false; > > @@ -690,15 +693,14 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * > if (drop_other_suboptions) > *size -= opt_size; > opts->suboptions |= OPTION_MPTCP_ADD_ADDR; > - if (!(add_addr & BIT(MPTCP_ADD_ADDR_ECHO)) && > - (add_addr & BIT(MPTCP_ADD_ADDR_SIGNAL))) { > + if (!echo) { > opts->ahmac = add_addr_generate_hmac(msk->local_key, > msk->remote_key, > &opts->local); > } > - pr_debug("addr_signal:%x, echo=%d, local_addr_id=%d, ahmac=%llu, local_port=%d, remote_addr_id=%d, remote_port=%d", > - add_addr, (opts->ahmac == 0), opts->local.id, opts->ahmac, > - ntohs(opts->local.port), opts->remote.id, ntohs(opts->remote.port)); > + pr_debug("local_id=%d, local_port=%d, remote_id=%d, remote_port=%d, ahmac=%llu, echo=%d", > + opts->local.id, ntohs(opts->local.port), opts->remote.id, > + ntohs(opts->remote.port), opts->ahmac, echo); > > return true; > } > @@ -1253,13 +1255,10 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp, > > mp_capable_done: > if (OPTION_MPTCP_ADD_ADDR & opts->suboptions) { > - struct mptcp_addr_info *addr = &opts->remote; > + struct mptcp_addr_info *addr = opts->ahmac ? &opts->local : &opts->remote; > u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE; > u8 echo = MPTCP_ADDR_ECHO; > > - if (opts->ahmac) > - addr = &opts->local; > - > #if IS_ENABLED(CONFIG_MPTCP_IPV6) > if (addr->family == AF_INET6) > len = TCPOLEN_MPTCP_ADD_ADDR6_BASE; > diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c > index 264f522af530..399b59cb7563 100644 > --- a/net/mptcp/pm.c > +++ b/net/mptcp/pm.c > @@ -253,12 +253,13 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup) > > /* path manager helpers */ > > -bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb, > - unsigned int opt_size, unsigned int remaining, > - struct mptcp_out_options *opts, u8 *add_addr) > +bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining, > + struct mptcp_addr_info *saddr, struct mptcp_addr_info *daddr, > + bool *echo, bool *port) > { > int ret = false; > u8 add_addr; > + u8 family; > > spin_lock_bh(&msk->pm.lock); > > @@ -266,21 +267,15 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb, > if (!mptcp_pm_should_add_signal(msk)) > goto out_unlock; > > - opts->local = msk->pm.local; > - opts->remote = msk->pm.remote; > - *add_addr = msk->pm.addr_signal; > + *echo = mptcp_pm_should_add_signal_echo(msk); > + *port = !!(*echo ? msk->pm.remote.port : msk->pm.local.port); > > - if (((msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_ECHO)) || > - ((msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL)) && > - (msk->pm.local.family == AF_INET6 || msk->pm.local.port))) && > - skb && skb_is_tcp_pure_ack(skb)) { > - remaining += opt_size; > - } > - > - if (remaining < mptcp_add_addr_len(opts, *add_addr)) > + family = *echo ? msk->pm.remote.family : msk->pm.local.family; > + if (remaining < mptcp_add_addr_len(family, *echo, *port)) > goto out_unlock; > > *saddr = msk->pm.local; > + *daddr = msk->pm.remote; > add_addr = READ_ONCE(msk->pm.addr_signal); > if (mptcp_pm_should_add_signal_echo(msk)) > add_addr &= ~BIT(MPTCP_ADD_ADDR_ECHO); > diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h > index 937e0309e340..4b63cc6079fa 100644 > --- a/net/mptcp/protocol.h > +++ b/net/mptcp/protocol.h > @@ -766,25 +766,16 @@ static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk) > return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL); > } > > -static inline unsigned int mptcp_add_addr_len(struct mptcp_out_options *opts, > - u8 add_addr) > +static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port) > { > - struct mptcp_addr_info *addr = &opts->remote; > - u8 len = 0; > + u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE; > > - if (!(add_addr & BIT(MPTCP_ADD_ADDR_ECHO)) && > - (add_addr & BIT(MPTCP_ADD_ADDR_SIGNAL))) { > - addr = &opts->local; > + if (family == AF_INET6) > + len = TCPOLEN_MPTCP_ADD_ADDR6_BASE; > + if (!echo) > len += MPTCPOPT_THMAC_LEN; > - } > - > - if (addr->family == AF_INET6) > - len += TCPOLEN_MPTCP_ADD_ADDR6_BASE; > - else > - len += TCPOLEN_MPTCP_ADD_ADDR_BASE; > - > /* account for 2 trailing 'nop' options */ > - if (addr->port) > + if (port) > len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN; > > return len; > @@ -798,9 +789,9 @@ static inline int mptcp_rm_addr_len(const struct mptcp_rm_list *rm_list) > return TCPOLEN_MPTCP_RM_ADDR_BASE + roundup(rm_list->nr - 1, 4) + 1; > } > > -bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct sk_buff *skb, > - unsigned int opt_size, unsigned int remaining, > - struct mptcp_out_options *opts, u8 *add_addr); > +bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining, > + struct mptcp_addr_info *saddr, struct mptcp_addr_info *daddr, > + bool *echo, bool *port); > bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining, > struct mptcp_rm_list *rm_list); > int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc); > -- Li YongLong