diff options
| author | Davide Caratti <dcaratti@redhat.com> | 2021-05-25 14:23:13 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2021-05-25 15:56:20 -0700 |
| commit | d58300c3185b78ab910092488126b97f0abe3ae2 (patch) | |
| tree | c4f3cb3f50448f86525666eda4f15dcf0b1d374a /net/mptcp | |
| parent | 3ed0a585bfadb6bd7080f11184adbc9edcce7dbc (diff) | |
mptcp: validate 'id' when stopping the ADD_ADDR retransmit timer
when Linux receives an echo-ed ADD_ADDR, it checks the IP address against
the list of "announced" addresses. In case of a positive match, the timer
that handles retransmissions is stopped regardless of the 'Address Id' in
the received packet: this behaviour does not comply with RFC8684 3.4.1.
Fix it by validating the 'Address Id' in received echo-ed ADD_ADDRs.
Tested using packetdrill, with the following captured output:
unpatched kernel:
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 3013740213], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0xfd2e62517888fe29,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 3013740213], length 0
^^^ retransmission is stopped here, but 'Address Id' is 90
patched kernel:
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 1.2.3.4,mptcp dss ack 1672384568], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 90 198.51.100.2,mptcp dss ack 1672384568], length 0
Out <...> Flags [.], ack 1, win 256, options [mptcp add-addr v1 id 1 198.51.100.2 hmac 0x1cf372d59e05f4b8,mptcp dss ack 3007449509], length 0
In <...> Flags [.], ack 1, win 257, options [mptcp add-addr v1-echo id 1 198.51.100.2,mptcp dss ack 1672384568], length 0
^^^ retransmission is stopped here, only when both 'Address Id' and 'IP Address' match
Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
| -rw-r--r-- | net/mptcp/options.c | 2 | ||||
| -rw-r--r-- | net/mptcp/pm_netlink.c | 8 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 2 |
3 files changed, 6 insertions, 6 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 71c535f4e1ef..6b825fb3fa83 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -1023,7 +1023,7 @@ void mptcp_incoming_options(struct sock *sk, struct sk_buff *skb) MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ADDADDR); } else { mptcp_pm_add_addr_echoed(msk, &mp_opt.addr); - mptcp_pm_del_add_timer(msk, &mp_opt.addr); + mptcp_pm_del_add_timer(msk, &mp_opt.addr, true); MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_ECHOADD); } diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 6ba040897738..2469e06a3a9d 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -346,18 +346,18 @@ out: struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, - struct mptcp_addr_info *addr) + struct mptcp_addr_info *addr, bool check_id) { struct mptcp_pm_add_entry *entry; struct sock *sk = (struct sock *)msk; spin_lock_bh(&msk->pm.lock); entry = mptcp_lookup_anno_list_by_saddr(msk, addr); - if (entry) + if (entry && (!check_id || entry->addr.id == addr->id)) entry->retrans_times = ADD_ADDR_RETRANS_MAX; spin_unlock_bh(&msk->pm.lock); - if (entry) + if (entry && (!check_id || entry->addr.id == addr->id)) sk_stop_timer_sync(sk, &entry->add_timer); return entry; @@ -1064,7 +1064,7 @@ static bool remove_anno_list_by_saddr(struct mptcp_sock *msk, { struct mptcp_pm_add_entry *entry; - entry = mptcp_pm_del_add_timer(msk, addr); + entry = mptcp_pm_del_add_timer(msk, addr, false); if (entry) { list_del(&entry->list); kfree(entry); diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 165c8b40b384..0c6f99c67345 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -672,7 +672,7 @@ void mptcp_pm_free_anno_list(struct mptcp_sock *msk); bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk); struct mptcp_pm_add_entry * mptcp_pm_del_add_timer(struct mptcp_sock *msk, - struct mptcp_addr_info *addr); + struct mptcp_addr_info *addr, bool check_id); struct mptcp_pm_add_entry * mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk, struct mptcp_addr_info *addr); |