mptcp: add port number check for MP_JOIN

This patch adds two new helpers, subflow_use_different_sport and
subflow_use_different_dport, to check whether the subflow's source or
destination port number is different from the msk's port number. When
receiving the MP_JOIN's SYN/SYNACK/ACK, we do these port number checks
and print out the different port numbers.

And furthermore, when receiving the MP_JOIN's SYN/ACK, we also use a new
helper mptcp_pm_sport_in_anno_list to check whether this port number is
announced. If it isn't, we need to abort this connection.

This patch also populates the local address's port field in
local_address.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Geliang Tang 2021-02-01 15:09:15 -08:00 committed by Jakub Kicinski
parent ec20e14396
commit 5bc56388c7
3 changed files with 61 additions and 1 deletions

View File

@ -97,8 +97,8 @@ static bool address_zero(const struct mptcp_addr_info *addr)
static void local_address(const struct sock_common *skc,
struct mptcp_addr_info *addr)
{
addr->port = 0;
addr->family = skc->skc_family;
addr->port = htons(skc->skc_num);
if (addr->family == AF_INET)
addr->addr.s_addr = skc->skc_rcv_saddr;
#if IS_ENABLED(CONFIG_MPTCP_IPV6)
@ -254,6 +254,27 @@ lookup_anno_list_by_saddr(struct mptcp_sock *msk,
return NULL;
}
bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
{
struct mptcp_pm_add_entry *entry;
struct mptcp_addr_info saddr;
bool ret = false;
local_address((struct sock_common *)sk, &saddr);
spin_lock_bh(&msk->pm.lock);
list_for_each_entry(entry, &msk->pm.anno_list, list) {
if (addresses_equal(&entry->addr, &saddr, true)) {
ret = true;
goto out;
}
}
out:
spin_unlock_bh(&msk->pm.lock);
return ret;
}
static void mptcp_pm_add_timer(struct timer_list *timer)
{
struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);

View File

@ -650,6 +650,7 @@ int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
struct mptcp_addr_info *addr,
u8 bkup);
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);

View File

@ -120,6 +120,11 @@ static int __subflow_init_req(struct request_sock *req, const struct sock *sk_li
return 0;
}
static bool subflow_use_different_sport(struct mptcp_sock *msk, const struct sock *sk)
{
return inet_sk(sk)->inet_sport != inet_sk((struct sock *)msk)->inet_sport;
}
/* Init mptcp request socket.
*
* Returns an error code if a JOIN has failed and a TCP reset
@ -192,6 +197,20 @@ again:
if (!subflow_req->msk)
return -EPERM;
if (subflow_use_different_sport(subflow_req->msk, sk_listener)) {
pr_debug("syn inet_sport=%d %d",
ntohs(inet_sk(sk_listener)->inet_sport),
ntohs(inet_sk((struct sock *)subflow_req->msk)->inet_sport));
if (!mptcp_pm_sport_in_anno_list(subflow_req->msk, sk_listener)) {
sock_put((struct sock *)subflow_req->msk);
mptcp_token_destroy_request(req);
tcp_request_sock_ops.destructor(req);
subflow_req->msk = NULL;
subflow_req->mp_join = 0;
return -EPERM;
}
}
subflow_req_create_thmac(subflow_req);
if (unlikely(req->syncookie)) {
@ -336,6 +355,11 @@ void mptcp_subflow_reset(struct sock *ssk)
sock_put(sk);
}
static bool subflow_use_different_dport(struct mptcp_sock *msk, const struct sock *sk)
{
return inet_sk(sk)->inet_dport != inet_sk((struct sock *)msk)->inet_dport;
}
static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
{
struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
@ -402,6 +426,12 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)
subflow->mp_join = 1;
MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKRX);
if (subflow_use_different_dport(mptcp_sk(parent), sk)) {
pr_debug("synack inet_dport=%d %d",
ntohs(inet_sk(sk)->inet_dport),
ntohs(inet_sk(parent)->inet_dport));
}
} else if (mptcp_check_fallback(sk)) {
fallback:
mptcp_rcv_space_init(mptcp_sk(parent), sk);
@ -667,6 +697,14 @@ create_child:
SUBFLOW_REQ_INC_STATS(req, MPTCP_MIB_JOINACKRX);
tcp_rsk(req)->drop_req = true;
if (subflow_use_different_sport(owner, sk)) {
pr_debug("ack inet_sport=%d %d",
ntohs(inet_sk(sk)->inet_sport),
ntohs(inet_sk((struct sock *)owner)->inet_sport));
if (!mptcp_pm_sport_in_anno_list(owner, sk))
goto out;
}
}
}