iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mptcp: move drop_other_suboptions check under pm lock

Browse Source 
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: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Co-developed-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Yonglong Li <liyonglong@chinatelecom.cn>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Yonglong Li 2021-08-23 18:05:39 -07:00 committed by David S. Miller
parent faf482ca19
commit 1f5e9e2f5f
3 changed files with 31 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

28
net/mptcp/options.c
View File

@ -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,

15
net/mptcp/pm.c
View File

@ -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);

6
net/mptcp/protocol.h
View File

@ -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);