Commit 1f5e9e2f authored by Yonglong Li's avatar Yonglong Li Committed by David S. Miller
Browse files

mptcp: move drop_other_suboptions check under pm lock 



This patch moved the drop_other_suboptions check from
mptcp_established_options_add_addr() into mptcp_pm_add_addr_signal(), do
it under the PM lock to avoid the race between this check and
mptcp_pm_add_addr_signal().

For this, added a new parameter for mptcp_pm_add_addr_signal() to get
the drop_other_suboptions value. And drop the other suboptions after the
option length check if drop_other_suboptions is true.

Additionally, always drop the other suboption for TCP pure ack:
that makes both the code simpler and the MPTCP behaviour more
consistent.

Co-developed-by: default avatarGeliang Tang <geliangtang@gmail.com>
Signed-off-by: default avatarGeliang Tang <geliangtang@gmail.com>
Co-developed-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Signed-off-by: default avatarYonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: default avatarMat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent faf482ca

net/mptcp/options.c

+14 −14
Original line number Diff line number Diff line
@@ -667,29 +667,29 @@ static bool mptcp_established_options_add_addr(struct sock *sk, struct sk_buff * 
	bool port;

	int len;



	if ((mptcp_pm_should_add_signal_ipv6(msk) ||

	     mptcp_pm_should_add_signal_port(msk) ||

	     mptcp_pm_should_add_signal_echo(msk)) &&

	    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;

	}



	/* add addr will strip the existing options, be sure to avoid breaking

	 * MPC/MPJ handshakes

	 */

	if (!mptcp_pm_should_add_signal(msk) ||

	    !(mptcp_pm_add_addr_signal(msk, remaining, &opts->addr, &echo, &port)))

	    (opts->suboptions & (OPTION_MPTCP_MPJ_ACK | OPTION_MPTCP_MPC_ACK)) ||

	    !mptcp_pm_add_addr_signal(msk, skb, opt_size, remaining, &opts->addr,

		    &echo, &port, &drop_other_suboptions))

		return false;



	if (drop_other_suboptions)

		remaining += opt_size;

	len = mptcp_add_addr_len(opts->addr.family, echo, port);

	if (remaining < len)

		return false;



	*size = len;

	if (drop_other_suboptions)

	if (drop_other_suboptions) {

		pr_debug("drop other suboptions");

		opts->suboptions = 0;

		opts->ext_copy.use_ack = 0;

		opts->ext_copy.use_map = 0;

		*size -= opt_size;

	}

	opts->suboptions |= OPTION_MPTCP_ADD_ADDR;

	if (!echo) {

		opts->ahmac = add_addr_generate_hmac(msk->local_key,

net/mptcp/pm.c

+13 −2
Original line number Diff line number Diff line
@@ -251,8 +251,10 @@ 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 sk_buff *skb,

			      unsigned int opt_size, unsigned int remaining,

			      struct mptcp_addr_info *saddr, bool *echo,

			      bool *port, bool *drop_other_suboptions)

{

	int ret = false;
@@ -262,6 +264,15 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining, 
	if (!mptcp_pm_should_add_signal(msk))

		goto out_unlock;



	/* always drop every other options for pure ack ADD_ADDR; this is a

	 * plain dup-ack from TCP perspective. The other MPTCP-relevant info,

	 * if any, will be carried by the 'original' TCP ack

	 */

	if (skb && skb_is_tcp_pure_ack(skb)) {

		remaining += opt_size;

		*drop_other_suboptions = true;

	}



	*echo = mptcp_pm_should_add_signal_echo(msk);

	*port = mptcp_pm_should_add_signal_port(msk);

net/mptcp/protocol.h

+4 −2
Original line number Diff line number Diff line
@@ -794,8 +794,10 @@ 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 sk_buff *skb,

			      unsigned int opt_size, unsigned int remaining,

			      struct mptcp_addr_info *saddr, bool *echo,

			      bool *port, bool *drop_other_suboptions);

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);