mptcp: send out ADD_ADDR with echo flag

When the ADD_ADDR suboption has been received, we need to send out the same
ADD_ADDR suboption with echo-flag=1, and no HMAC.

Suggested-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/options.c b/net/mptcp/options.c
index a52a05e..a41996e 100644 (file)
--- a/net/mptcp/options.c
+++ b/net/mptcp/options.c
@@ -242,7 +242,7 @@ static void mptcp_parse_option(const struct sk_buff *skb,
                mp_opt->add_addr = 1;
                mp_opt->port = 0;
                mp_opt->addr_id = *ptr++;
-               pr_debug("ADD_ADDR: id=%d", mp_opt->addr_id);
+               pr_debug("ADD_ADDR: id=%d, echo=%d", mp_opt->addr_id, mp_opt->echo);
                if (mp_opt->family == MPTCP_ADDR_IPVERSION_4) {
                        memcpy((u8 *)&mp_opt->addr.s_addr, (u8 *)ptr, 4);
                        ptr += 4;
@@ -579,10 +579,11 @@ static bool mptcp_established_options_add_addr(struct sock *sk,
        struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
        struct mptcp_sock *msk = mptcp_sk(subflow->conn);
        struct mptcp_addr_info saddr;
+       bool echo;
        int len;
 
        if (!mptcp_pm_should_add_signal(msk) ||
-           !(mptcp_pm_add_addr_signal(msk, remaining, &saddr)))
+           !(mptcp_pm_add_addr_signal(msk, remaining, &saddr, &echo)))
                return false;
 
        len = mptcp_add_addr_len(saddr.family);
@@ -594,22 +595,26 @@ static bool mptcp_established_options_add_addr(struct sock *sk,
        if (saddr.family == AF_INET) {
                opts->suboptions |= OPTION_MPTCP_ADD_ADDR;
                opts->addr = saddr.addr;
-               opts->ahmac = add_addr_generate_hmac(msk->local_key,
-                                                    msk->remote_key,
-                                                    opts->addr_id,
-                                                    &opts->addr);
+               if (!echo) {
+                       opts->ahmac = add_addr_generate_hmac(msk->local_key,
+                                                            msk->remote_key,
+                                                            opts->addr_id,
+                                                            &opts->addr);
+               }
        }
 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
        else if (saddr.family == AF_INET6) {
                opts->suboptions |= OPTION_MPTCP_ADD_ADDR6;
                opts->addr6 = saddr.addr6;
-               opts->ahmac = add_addr6_generate_hmac(msk->local_key,
-                                                     msk->remote_key,
-                                                     opts->addr_id,
-                                                     &opts->addr6);
+               if (!echo) {
+                       opts->ahmac = add_addr6_generate_hmac(msk->local_key,
+                                                             msk->remote_key,
+                                                             opts->addr_id,
+                                                             &opts->addr6);
+               }
        }
 #endif
-       pr_debug("addr_id=%d, ahmac=%llu", opts->addr_id, opts->ahmac);
+       pr_debug("addr_id=%d, ahmac=%llu, echo=%d", opts->addr_id, opts->ahmac, echo);
 
        return true;
 }

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 558462d..39a7662 100644 (file)
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -13,11 +13,13 @@
 /* path manager command handlers */
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
-                          const struct mptcp_addr_info *addr)
+                          const struct mptcp_addr_info *addr,
+                          bool echo)
 {
        pr_debug("msk=%p, local_id=%d", msk, addr->id);
 
        msk->pm.local = *addr;
+       WRITE_ONCE(msk->pm.add_addr_echo, echo);
        WRITE_ONCE(msk->pm.add_addr_signal, true);
        return 0;
 }
@@ -135,15 +137,11 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
        pr_debug("msk=%p remote_id=%d accept=%d", msk, addr->id,
                 READ_ONCE(pm->accept_addr));
 
-       /* avoid acquiring the lock if there is no room for fouther addresses */
-       if (!READ_ONCE(pm->accept_addr))
-               return;
-
        spin_lock_bh(&pm->lock);
 
-       /* be sure there is something to signal re-checking under PM lock */
-       if (READ_ONCE(pm->accept_addr) &&
-           mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
+       if (!READ_ONCE(pm->accept_addr))
+               mptcp_pm_announce_addr(msk, addr, true);
+       else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED))
                pm->remote = *addr;
 
        spin_unlock_bh(&pm->lock);
@@ -164,7 +162,7 @@ void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id)
 /* path manager helpers */
 
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-                             struct mptcp_addr_info *saddr)
+                             struct mptcp_addr_info *saddr, bool *echo)
 {
        int ret = false;
 
@@ -178,6 +176,7 @@ bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
                goto out_unlock;
 
        *saddr = msk->pm.local;
+       *echo = READ_ONCE(msk->pm.add_addr_echo);
        WRITE_ONCE(msk->pm.add_addr_signal, false);
        ret = true;
 
@@ -226,6 +225,7 @@ void mptcp_pm_data_init(struct mptcp_sock *msk)
        WRITE_ONCE(msk->pm.rm_addr_signal, false);
        WRITE_ONCE(msk->pm.accept_addr, false);
        WRITE_ONCE(msk->pm.accept_subflow, false);
+       WRITE_ONCE(msk->pm.add_addr_echo, false);
        msk->pm.status = 0;
 
        spin_lock_init(&msk->pm.lock);

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 4124bc5..f6f96bc 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -198,7 +198,7 @@ static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 
                if (local) {
                        msk->pm.add_addr_signaled++;
-                       mptcp_pm_announce_addr(msk, &local->addr);
+                       mptcp_pm_announce_addr(msk, &local->addr, false);
                } else {
                        /* pick failed, avoid fourther attempts later */
                        msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
@@ -266,6 +266,8 @@ void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
        spin_unlock_bh(&msk->pm.lock);
        __mptcp_subflow_connect((struct sock *)msk, &local, &remote);
        spin_lock_bh(&msk->pm.lock);
+
+       mptcp_pm_announce_addr(msk, &remote, true);
 }
 
 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 837e010..ba253a6 100644 (file)
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -169,6 +169,7 @@ struct mptcp_pm_data {
        bool            work_pending;
        bool            accept_addr;
        bool            accept_subflow;
+       bool            add_addr_echo;
        u8              add_addr_signaled;
        u8              add_addr_accepted;
        u8              local_addr_used;
@@ -442,7 +443,8 @@ void mptcp_pm_add_addr_received(struct mptcp_sock *msk,
 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk, u8 rm_id);
 
 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
-                          const struct mptcp_addr_info *addr);
+                          const struct mptcp_addr_info *addr,
+                          bool echo);
 int mptcp_pm_remove_addr(struct mptcp_sock *msk, u8 local_id);
 int mptcp_pm_remove_subflow(struct mptcp_sock *msk, u8 remote_id);
 
@@ -464,7 +466,7 @@ static inline unsigned int mptcp_add_addr_len(int family)
 }
 
 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
-                             struct mptcp_addr_info *saddr);
+                             struct mptcp_addr_info *saddr, bool *echo);
 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
                             u8 *rm_id);
 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc);