From: Yonglong Li <liyonglong@chinatelecom.cn>
To: Geliang Tang <geliangtang@gmail.com>
Cc: mptcp@lists.linux.dev,
Mat Martineau <mathew.j.martineau@linux.intel.com>
Subject: Re: [PATCH v6 3/4] mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal
Date: Tue, 29 Jun 2021 15:54:35 +0800 [thread overview]
Message-ID: <2f36e070-496f-c7a7-cb5a-26787db05dbd@chinatelecom.cn> (raw)
In-Reply-To: <CA+WQbwtW-H6NoHFV=xqfVsGJ4Z5YwQkOd8vu=JSiuJyztx3Kzg@mail.gmail.com>
On 2021/6/29 15:35, Geliang Tang wrote:
> Yonglong Li <liyonglong@chinatelecom.cn> 于2021年6月29日周二 下午3:02写道：
>>
>>
>> Hi Geiliang, Thanks for your reviews.
>>
>> On 2021/6/29 13:58, Geliang Tang wrote:
>>> Yonglong Li <liyonglong@chinatelecom.cn> 于2021年6月29日周二 上午9:42写道：
>>>>
>>>> according MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO flag build
>>>> ADD_ADDR/echo-ADD_ADDR option
>>>>
>>>> add a suboptions type OPTION_MPTCP_ADD_ECHO to mark as echo option
>>>>
>>>> Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
>>>> ---
>>>> include/net/mptcp.h | 3 ++-
>>>> net/mptcp/options.c | 65 +++++++++++++++++++++++++++++++---------------------
>>>> net/mptcp/pm.c | 33 +++++++++++---------------
>>>> net/mptcp/protocol.h | 23 ++++++++++++-------
>>>> 4 files changed, 69 insertions(+), 55 deletions(-)
>>>>
>>>> diff --git a/include/net/mptcp.h b/include/net/mptcp.h
>>>> index d61bbbf..d2c6ebe 100644
>>>> --- a/include/net/mptcp.h
>>>> +++ b/include/net/mptcp.h
>>>> @@ -61,7 +61,8 @@ struct mptcp_out_options {
>>>> u64 sndr_key;
>>>> u64 rcvr_key;
>>>> u64 ahmac;
>>>> - struct mptcp_addr_info addr;
>>>> + struct mptcp_addr_info local;
>>>> + struct mptcp_addr_info remote;
>>>> struct mptcp_rm_list rm_list;
>>>> u8 join_id;
>>>> u8 backup;
>>>> diff --git a/net/mptcp/options.c b/net/mptcp/options.c
>>>> index 1aec016..1707bec 100644
>>>> --- a/net/mptcp/options.c
>>>> +++ b/net/mptcp/options.c
>>>> @@ -655,13 +655,15 @@ 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;
>>>> - bool echo;
>>>> - bool port;
>>>> - int len;
>>>> + u8 add_addr, flags = 0xff;
>>>> + int len = 0;
>>>>
>>>> - if ((mptcp_pm_should_add_signal_ipv6(msk) ||
>>>> - mptcp_pm_should_add_signal_port(msk) ||
>>>> - mptcp_pm_should_add_signal_echo(msk)) &&
>>>> + if (!mptcp_pm_add_addr_signal(msk, opts, &add_addr))
>>>> + return false;
>>>
>>> This add_addr argument is useless, let's drop it.
>>>
>> we can use add_addr use in debug log.
>
> I think it's not worth adding a new argument just for debugging.
agree.
>
>>
>>> And here add back mptcp_pm_should_add_signal check here. The original code
>>> called mptcp_pm_should_add_signal twice for double check, once out of pm
>>> lock, once under pm lock. We should keep it.
>> Sorry, I think double check is not necessary. does we need double check?
>
> I think we should keep the original logic here. If we want to drop this
> double check or something, we should do it in another patch, don't mix too
> much things in one patch.
agree.
>
>>
>>>
>>>> +
>>>> + if ((mptcp_pm_should_add_signal_echo(msk) ||
>>>> + (mptcp_pm_should_add_signal_addr(msk) &&
>>>> + (opts->local.family == AF_INET6 || opts->local.port))) &&
>>>> skb && skb_is_tcp_pure_ack(skb)) {
>>>> pr_debug("drop other suboptions");
>>>> opts->suboptions = 0;
>>>> @@ -671,11 +673,17 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff *
>>>> drop_other_suboptions = true;
>>>> }
>>>>
>>>> - if (!mptcp_pm_should_add_signal(msk) ||
>>>> - !(mptcp_pm_add_addr_signal(msk, remaining, &opts->addr, &echo, &port)))
>>>> - return false;
>>>>
>>>> - len = mptcp_add_addr_len(opts->addr.family, echo, port);
>>>> + if (mptcp_pm_should_add_signal_echo(msk)) {
>>>> + flags = (u8)~BIT(MPTCP_ADD_ADDR_ECHO);
>>>> + } else {
>>>> + opts->ahmac = add_addr_generate_hmac(msk->local_key,
>>>> + msk->remote_key,
>>>> + &opts->local);
>>>
>>> Keep this ahmac generating code after opts->suboptions set just like the
>>> original code, since ahmac is the more expensive to populate. If remaining
>>> length isn't enough, no need to set ahmac.
>>
>> because mptcp_add_addr_len(opts) will use ahmac to calculate len of opts, so I think Keep this ahmac
>> generating code after opts->suboptions set is not ok.
>
> So we should use mptcp_pm_should_add_signal_addr instead of opts->ahmac in
> mptcp_add_addr_len.
agree.
>
>>
>>>
>>>> + flags = (u8)~BIT(MPTCP_ADD_ADDR_SIGNAL);
>>>> + }
>>>> +
>>>> + len = mptcp_add_addr_len(opts);
>>>> if (remaining < len)
>>>> return false;
>>>>
>>>> @@ -683,13 +691,14 @@ 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 (!echo) {
>>>> - opts->ahmac = add_addr_generate_hmac(msk->local_key,
>>>> - msk->remote_key,
>>>> - &opts->addr);
>>>> - }
>>>> - pr_debug("addr_id=%d, ahmac=%llu, echo=%d, port=%d",
>>>> - opts->addr.id, opts->ahmac, echo, ntohs(opts->addr.port));
>>>> +
>>>> + spin_lock_bh(&msk->pm.lock);
>>>> + WRITE_ONCE(msk->pm.addr_signal, flags & msk->pm.addr_signal);
>>>> + spin_unlock_bh(&msk->pm.lock);
>>>
>>> addr_signal has been set in mptcp_pm_add_addr_signal in patch 1, no need to
>>> set it again. I thinks this trunk and all the flags set above should be
>>> dropped.
>>
>> Because MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO maybe set at the same time.
>> So i think we should only unset one flag.
>
> We can only unset one flag in mptcp_pm_add_addr_signal, see my comment in
> patch 1.
if change like this. there is a issue: if remaining len checking is not ok and return false, The ADD_ADDR/ECHO event will
be clear. So I think we should make sure ADD_ADDR/ECHO option will add in packet before clean flags. WDYT?
>
> -Geliang
>
>>
>>>
>>>> +
>>>> + 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));
>>>>
>>>> return true;
>>>> }
>>>
>>> The whole function is something like this:
>>> '''
>>> struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
>>> struct mptcp_sock *msk = mptcp_sk(subflow->conn);
>>> bool drop_other_suboptions = false;
>>> unsigned int opt_size = *size;
>>> int len;
>>>
>>> if (!mptcp_pm_should_add_signal(msk) ||
>>> !mptcp_pm_add_addr_signal(msk, remaining, opts))
>>> return false;
>>>
>>> if ((mptcp_pm_should_add_signal_echo(msk) ||
>>> (mptcp_pm_should_add_signal_addr(msk) &&
>>> (opts->local.family == AF_INET6 || opts->local.port))) &&
>>> skb && skb_is_tcp_pure_ack(skb)) {
>>> pr_debug("drop other suboptions");
>>> opts->suboptions = 0;
>>> opts->ext_copy.use_ack = 0;
>>> opts->ext_copy.use_map = 0;
>>> remaining += opt_size;
>>> drop_other_suboptions = true;
>>> }
>>>
>>> len = mptcp_add_addr_len(opts);
>>> if (remaining < len)
>>> return false;
>>>
>>> *size = len;
>>> if (drop_other_suboptions)
>>> *size -= opt_size;
>>> opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
>>> if (mptcp_pm_should_add_signal_addr(msk)) {
>>> 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",
>>> msk->pm.addr_signal, (opts->ahmac == 0), opts->local.id,
>>> opts->ahmac, ntohs(opts->local.port),
>>> opts->remote.id, ntohs(opts->remote.port));
>>>
>>> return true;
>>> '''
>>>
>>>> @@ -1229,15 +1238,19 @@ 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;
>>>
>>> We can simplify it like this:
>>> 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;
>>>
>>> And this trunk can be dropped.
>>>
>>>> +
>>>> #if IS_ENABLED(CONFIG_MPTCP_IPV6)
>>>> - if (opts->addr.family == AF_INET6)
>>>> + if (addr->family == AF_INET6)
>>>> len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
>>>> #endif
>>>>
>>>> - if (opts->addr.port)
>>>> + if (addr->port)
>>>> len += TCPOLEN_MPTCP_PORT_LEN;
>>>>
>>>> if (opts->ahmac) {
>>>> @@ -1246,25 +1259,25 @@ void mptcp_write_options(__be32 *ptr, const struct tcp_sock *tp,
>>>> }
>>>>
>>>> *ptr++ = mptcp_option(MPTCPOPT_ADD_ADDR,
>>>> - len, echo, opts->addr.id);
>>>> - if (opts->addr.family == AF_INET) {
>>>> - memcpy((u8 *)ptr, (u8 *)&opts->addr.addr.s_addr, 4);
>>>> + len, echo, addr->id);
>>>> + if (addr->family == AF_INET) {
>>>> + memcpy((u8 *)ptr, (u8 *)&addr->addr.s_addr, 4);
>>>> ptr += 1;
>>>> }
>>>> #if IS_ENABLED(CONFIG_MPTCP_IPV6)
>>>> - else if (opts->addr.family == AF_INET6) {
>>>> - memcpy((u8 *)ptr, opts->addr.addr6.s6_addr, 16);
>>>> + else if (addr->family == AF_INET6) {
>>>> + memcpy((u8 *)ptr, addr->addr6.s6_addr, 16);
>>>> ptr += 4;
>>>> }
>>>> #endif
>>>>
>>>> - if (!opts->addr.port) {
>>>> + if (!addr->port) {
>>>> if (opts->ahmac) {
>>>> put_unaligned_be64(opts->ahmac, ptr);
>>>> ptr += 2;
>>>> }
>>>> } else {
>>>> - u16 port = ntohs(opts->addr.port);
>>>> + u16 port = ntohs(addr->port);
>>>>
>>>> if (opts->ahmac) {
>>>> u8 *bptr = (u8 *)ptr;
>>>> diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
>>>> index cf873e9..9c621293 100644
>>>> --- a/net/mptcp/pm.c
>>>> +++ b/net/mptcp/pm.c
>>>> @@ -253,32 +253,25 @@ void mptcp_pm_mp_prio_received(struct sock *sk, u8 bkup)
>>>>
>>>> /* path manager helpers */
>>>>
>>>> -bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>>> - struct mptcp_addr_info *saddr, bool *echo, bool *port)
>>>> +bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct mptcp_out_options *opts,
>>>> + u8 *add_addr)
>>>
>>> Drop this add_addr argument.
>>>
>>>> {
>>>> - u8 add_addr;
>>>> - int ret = false;
>>>> -
>>>> spin_lock_bh(&msk->pm.lock);
>>>>
>>>> - /* double check after the lock is acquired */
>>>> - if (!mptcp_pm_should_add_signal(msk))
>>>> - goto out_unlock;
>>>
>>> Keep this double check code.
>>>
>>>> -
>>>> - *echo = mptcp_pm_should_add_signal_echo(msk);
>>>> - *port = mptcp_pm_should_add_signal_port(msk);
>>>> -
>>>> - if (remaining < mptcp_add_addr_len(msk->pm.local.family, *echo, *port))
>>>> - goto out_unlock;
>>>
>>> Keep this length double check code too.
>>>
>>>> + if (!mptcp_pm_should_add_signal(msk)) {
>>>> + spin_unlock_bh(&msk->pm.lock);
>>>> + return false;
>>>> + }
>>>>
>>>> - *saddr = msk->pm.local;
>>>> - add_addr = msk->pm.addr_signal & ~(BIT(MPTCP_ADD_ADDR_SIGNAL) | BIT(MPTCP_ADD_ADDR_ECHO));
>>> - WRITE_ONCE(msk->pm.addr_signal, add_addr);
>>>
>>> This code is just added in patch 1, I think we should keep it. And no need
>>> to write addr_signal again in mptcp_established_options_add_addr.
>>>
>>>> - ret = true;
>>>> + opts->local = msk->pm.local;
>>>> + opts->remote = msk->pm.remote;
>>>> + *add_addr = msk->pm.addr_signal;
>>>>
>>>> -out_unlock:
>>>> spin_unlock_bh(&msk->pm.lock);
>>>> - return ret;
>>>
>>> Keep this out_unlock code.
>>>
>>>> +
>>>> + if ((mptcp_pm_should_add_signal_echo(msk)) && (mptcp_pm_should_add_signal_addr(msk)))
>>>> + mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);
>>>
>>> Could we use mptcp_pm_add_addr_send_ack here instead of open coding?
>>>
>>> I'm no sure why we need this two lines, and why you use '&&' here. Do you
>>> mean set MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO at the same time?
>>>
>>>> + return true;
>>>> }
>>>
>>> The whole function is something like this:
>>> '''
>>> int ret = false;
>>> u8 add_addr;
>>>
>>> spin_lock_bh(&msk->pm.lock);
>>>
>>> /* double check after the lock is acquired */
>>> if (!mptcp_pm_should_add_signal(msk))
>>> goto out_unlock;
>>>
>>> if (remaining < mptcp_add_addr_len(opts))
>>> goto out_unlock;
>>>
>>> opts->local = msk->pm.local;
>>> opts->remote = msk->pm.remote;
>>> if (mptcp_pm_should_add_signal_echo(msk))
>>> add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO);
>>> else
>>> add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL);
>>> WRITE_ONCE(msk->pm.addr_signal, add_addr);
>>> ret = true;
>>>
>>> out_unlock:
>>> spin_unlock_bh(&msk->pm.lock);
>>> if (ret && mptcp_pm_should_add_signal_echo(msk) &&
>>> mptcp_pm_should_add_signal_addr(msk))
>>> mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);
>>> return ret;
>>> '''
>>>
>>>>
>>>> bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
>>>> diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
>>>> index a0b0ec0..0bfbbdef 100644
>>>> --- a/net/mptcp/protocol.h
>>>> +++ b/net/mptcp/protocol.h
>>>> @@ -737,16 +737,23 @@ 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(int family, bool echo, bool port)
>>>> +static inline unsigned int mptcp_add_addr_len(struct mptcp_out_options *opts)
>>>> {
>>>> - u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
>>>> + u8 len = 0;
>>>> + struct mptcp_addr_info *addr = &opts->remote;
>>>
>>> We can simplify it like this:
>>> struct mptcp_addr_info *addr = opts->ahmac ? &opts->local :
>>> &opts->remote;
>>>
>>> And keep the orignal code unchanged.
>>>
>>>>
>>>> - if (family == AF_INET6)
>>>> - len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
>>>> - if (!echo)
>>>> + if (opts->ahmac) {
>>>> + addr = &opts->local;
>>>> 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 (port)
>>>> + if (addr->port)
>>>> len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
>>>>
>>>> return len;
>>>
>>> The whole function is something like this:
>>> '''
>>> struct mptcp_addr_info *addr = opts->ahmac ? &opts->local :
>>> &opts->remote;
>>> u8 len = TCPOLEN_MPTCP_ADD_ADDR_BASE;
>>>
>>> if (addr->family == AF_INET6)
>>> len = TCPOLEN_MPTCP_ADD_ADDR6_BASE;
>>> if (opts->ahmac)
>>> len += MPTCPOPT_THMAC_LEN;
>>> /* account for 2 trailing 'nop' options */
>>> if (addr->port)
>>> len += TCPOLEN_MPTCP_PORT_LEN + TCPOLEN_MPTCP_PORT_ALIGN;
>>>
>>> return len;
>>> '''
>>>
>>> Thanks.
>>> -Geliang
>>>
>>>> @@ -760,8 +767,8 @@ 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, unsigned int remaining,
>>>> - struct mptcp_addr_info *saddr, bool *echo, bool *port);
>>>> +bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, struct mptcp_out_options *opts,
>>>> + u8 *add_addr);
>>>> 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);
>>>> --
>>>> 1.8.3.1
>>>>
>>>>
>>>
>>>
>>
>> --
>> Li YongLong
>
--
Li YongLong
next prev parent reply other threads:[~2021-06-29 7:54 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-29 1:41 [PATCH v6 0/4] mptcp: fix conflicts when using pm.add_signal in ADD_ADDR/echo and RM_ADDR process Yonglong Li
2021-06-29 1:41 ` [PATCH v6 1/4] mptcp: fix ADD_ADDR and RM_ADDR maybe flush addr_signal each other Yonglong Li
2021-06-29 5:43 ` Geliang Tang
2021-06-29 1:41 ` [PATCH v6 2/4] mptcp: make MPTCP_ADD_ADDR_SIGNAL and MPTCP_ADD_ADDR_ECHO separate Yonglong Li
2021-06-29 1:41 ` [PATCH v6 3/4] mptcp: build ADD_ADDR/echo-ADD_ADDR option according pm.add_signal Yonglong Li
2021-06-29 5:58 ` Geliang Tang
2021-06-29 6:05 ` Geliang Tang
2021-06-29 7:01 ` Yonglong Li
2021-06-29 7:35 ` Geliang Tang
2021-06-29 7:54 ` Yonglong Li [this message]
2021-06-29 8:25 ` Geliang Tang
2021-06-30 1:30 ` Yonglong Li
2021-06-30 2:05 ` Geliang Tang
2021-06-30 6:50 ` Yonglong Li
2021-06-29 1:41 ` [PATCH v6 4/4] mptcp: remove MPTCP_ADD_ADDR_IPV6 and MPTCP_ADD_ADDR_PORT Yonglong Li
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