rxrpc: Fix firewall route keepalive

Fix the firewall route keepalive part of AF_RXRPC which is currently
function incorrectly by replying to VERSION REPLY packets from the server
with VERSION REQUEST packets.

Instead, send VERSION REPLY packets to the peers of service connections to
act as keep-alives 20s after the latest packet was transmitted to that
peer.

Also, just discard VERSION REPLY packets rather than replying to them.

Signed-off-by: David Howells <dhowells@redhat.com>

diff --git a/net/rxrpc/af_rxrpc.c b/net/rxrpc/af_rxrpc.c
index ec5ec68be1aae58eafcd4560212c56c97007bde2..0b3026b8fa40007fb6bbd733f7be720bb95ed04e 100644 (file)
--- a/net/rxrpc/af_rxrpc.c
+++ b/net/rxrpc/af_rxrpc.c
@@ -762,6 +762,7 @@ static __poll_t rxrpc_poll(struct file *file, struct socket *sock,
 static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
                        int kern)
 {
+       struct rxrpc_net *rxnet;
        struct rxrpc_sock *rx;
        struct sock *sk;
 
@@ -801,6 +802,9 @@ static int rxrpc_create(struct net *net, struct socket *sock, int protocol,
        rwlock_init(&rx->call_lock);
        memset(&rx->srx, 0, sizeof(rx->srx));
 
+       rxnet = rxrpc_net(sock_net(&rx->sk));
+       timer_reduce(&rxnet->peer_keepalive_timer, jiffies + 1);
+
        _leave(" = 0 [%p]", rx);
        return 0;
 }

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 21cf164b6d85aca7c2e18baf6da880246248df5e..8a348e0a9d95e79f2c87e57fc1ef29c8724b604a 100644 (file)
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -97,8 +97,16 @@ struct rxrpc_net {
        struct list_head        local_endpoints;
        struct mutex            local_mutex;    /* Lock for ->local_endpoints */
 
-       spinlock_t              peer_hash_lock; /* Lock for ->peer_hash */
        DECLARE_HASHTABLE       (peer_hash, 10);
+       spinlock_t              peer_hash_lock; /* Lock for ->peer_hash */
+
+#define RXRPC_KEEPALIVE_TIME 20 /* NAT keepalive time in seconds */
+       u8                      peer_keepalive_cursor;
+       ktime_t                 peer_keepalive_base;
+       struct hlist_head       peer_keepalive[RXRPC_KEEPALIVE_TIME + 1];
+       struct hlist_head       peer_keepalive_new;
+       struct timer_list       peer_keepalive_timer;
+       struct work_struct      peer_keepalive_work;
 };
 
 /*
@@ -285,6 +293,8 @@ struct rxrpc_peer {
        struct hlist_head       error_targets;  /* targets for net error distribution */
        struct work_struct      error_distributor;
        struct rb_root          service_conns;  /* Service connections */
+       struct hlist_node       keepalive_link; /* Link in net->peer_keepalive[] */
+       time64_t                last_tx_at;     /* Last time packet sent here */
        seqlock_t               service_conn_lock;
        spinlock_t              lock;           /* access lock */
        unsigned int            if_mtu;         /* interface MTU for this peer */
@@ -1026,6 +1036,7 @@ int rxrpc_send_ack_packet(struct rxrpc_call *, bool, rxrpc_serial_t *);
 int rxrpc_send_abort_packet(struct rxrpc_call *);
 int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *, bool);
 void rxrpc_reject_packets(struct rxrpc_local *);
+void rxrpc_send_keepalive(struct rxrpc_peer *);
 
 /*
  * peer_event.c
@@ -1034,6 +1045,7 @@ void rxrpc_error_report(struct sock *);
 void rxrpc_peer_error_distributor(struct work_struct *);
 void rxrpc_peer_add_rtt(struct rxrpc_call *, enum rxrpc_rtt_rx_trace,
                        rxrpc_serial_t, rxrpc_serial_t, ktime_t, ktime_t);
+void rxrpc_peer_keepalive_worker(struct work_struct *);
 
 /*
  * peer_object.c

diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index d2ec3fd593e8386571f5ce56063d87875418c164..c717152070dff2906d15aa53bd1c488bd42cf2c8 100644 (file)
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -136,6 +136,7 @@ static void rxrpc_conn_retransmit_call(struct rxrpc_connection *conn,
        }
 
        kernel_sendmsg(conn->params.local->socket, &msg, iov, ioc, len);
+       conn->params.peer->last_tx_at = ktime_get_real();
        _leave("");
        return;
 }
@@ -239,6 +240,8 @@ static int rxrpc_abort_connection(struct rxrpc_connection *conn,
                return -EAGAIN;
        }
 
+       conn->params.peer->last_tx_at = ktime_get_real();
+
        _leave(" = 0");
        return 0;
 }

diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 2a868fdab0ae5c83b0fd74104851b986571743ed..d4f2509e018b56bc47484f85daba26987bc2cb79 100644 (file)
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -1183,6 +1183,8 @@ void rxrpc_data_ready(struct sock *udp_sk)
 
        switch (sp->hdr.type) {
        case RXRPC_PACKET_TYPE_VERSION:
+               if (!(sp->hdr.flags & RXRPC_CLIENT_INITIATED))
+                       goto discard;
                rxrpc_post_packet_to_local(local, skb);
                goto out;
 

diff --git a/net/rxrpc/net_ns.c b/net/rxrpc/net_ns.c
index f18c9248e0d4c6108cb0ae82cc408e70d4aacbdb..66baf2b80b6cc0bf02c6a91ac96db2671f3298b7 100644 (file)
--- a/net/rxrpc/net_ns.c
+++ b/net/rxrpc/net_ns.c
@@ -32,13 +32,22 @@ static void rxrpc_service_conn_reap_timeout(struct timer_list *timer)
                rxrpc_queue_work(&rxnet->service_conn_reaper);
 }
 
+static void rxrpc_peer_keepalive_timeout(struct timer_list *timer)
+{
+       struct rxrpc_net *rxnet =
+               container_of(timer, struct rxrpc_net, peer_keepalive_timer);
+
+       if (rxnet->live)
+               rxrpc_queue_work(&rxnet->peer_keepalive_work);
+}
+
 /*
  * Initialise a per-network namespace record.
  */
 static __net_init int rxrpc_init_net(struct net *net)
 {
        struct rxrpc_net *rxnet = rxrpc_net(net);
-       int ret;
+       int ret, i;
 
        rxnet->live = true;
        get_random_bytes(&rxnet->epoch, sizeof(rxnet->epoch));
@@ -70,8 +79,16 @@ static __net_init int rxrpc_init_net(struct net *net)
 
        INIT_LIST_HEAD(&rxnet->local_endpoints);
        mutex_init(&rxnet->local_mutex);
+
        hash_init(rxnet->peer_hash);
        spin_lock_init(&rxnet->peer_hash_lock);
+       for (i = 0; i < ARRAY_SIZE(rxnet->peer_keepalive); i++)
+               INIT_HLIST_HEAD(&rxnet->peer_keepalive[i]);
+       INIT_HLIST_HEAD(&rxnet->peer_keepalive_new);
+       timer_setup(&rxnet->peer_keepalive_timer,
+                   rxrpc_peer_keepalive_timeout, 0);
+       INIT_WORK(&rxnet->peer_keepalive_work, rxrpc_peer_keepalive_worker);
+       rxnet->peer_keepalive_base = ktime_add(ktime_get_real(), NSEC_PER_SEC);
 
        ret = -ENOMEM;
        rxnet->proc_net = proc_net_mkdir(net, "rxrpc", net->proc_net);
@@ -95,6 +112,8 @@ static __net_exit void rxrpc_exit_net(struct net *net)
        struct rxrpc_net *rxnet = rxrpc_net(net);
 
        rxnet->live = false;
+       del_timer_sync(&rxnet->peer_keepalive_timer);
+       cancel_work_sync(&rxnet->peer_keepalive_work);
        rxrpc_destroy_all_calls(rxnet);
        rxrpc_destroy_all_connections(rxnet);
        rxrpc_destroy_all_locals(rxnet);

diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index cf73dc006c3bf0d3866461c63a5a7c51c161c90b..7f1fc04775b34e5abd8e24a450ae386e74bf194a 100644 (file)
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -32,6 +32,8 @@ struct rxrpc_abort_buffer {
        __be32 abort_code;
 };
 
+static const char rxrpc_keepalive_string[] = "";
+
 /*
  * Arrange for a keepalive ping a certain time after we last transmitted.  This
  * lets the far side know we're still interested in this call and helps keep
@@ -122,6 +124,7 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
        struct kvec iov[2];
        rxrpc_serial_t serial;
        rxrpc_seq_t hard_ack, top;
+       ktime_t now;
        size_t len, n;
        int ret;
        u8 reason;
@@ -203,8 +206,10 @@ int rxrpc_send_ack_packet(struct rxrpc_call *call, bool ping,
        }
 
        ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+       now = ktime_get_real();
        if (ping)
-               call->ping_time = ktime_get_real();
+               call->ping_time = now;
+       conn->params.peer->last_tx_at = ktime_get_real();
 
        if (call->state < RXRPC_CALL_COMPLETE) {
                if (ret < 0) {
@@ -288,6 +293,7 @@ int rxrpc_send_abort_packet(struct rxrpc_call *call)
 
        ret = kernel_sendmsg(conn->params.local->socket,
                             &msg, iov, 1, sizeof(pkt));
+       conn->params.peer->last_tx_at = ktime_get_real();
 
        rxrpc_put_connection(conn);
        return ret;
@@ -378,6 +384,7 @@ int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
         *     message and update the peer record
         */
        ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
+       conn->params.peer->last_tx_at = ktime_get_real();
 
        up_read(&conn->params.local->defrag_sem);
        if (ret == -EMSGSIZE)
@@ -429,6 +436,7 @@ send_fragmentable:
                if (ret == 0) {
                        ret = kernel_sendmsg(conn->params.local->socket, &msg,
                                             iov, 2, len);
+                       conn->params.peer->last_tx_at = ktime_get_real();
 
                        opt = IP_PMTUDISC_DO;
                        kernel_setsockopt(conn->params.local->socket, SOL_IP,
@@ -446,6 +454,7 @@ send_fragmentable:
                if (ret == 0) {
                        ret = kernel_sendmsg(conn->params.local->socket, &msg,
                                             iov, 2, len);
+                       conn->params.peer->last_tx_at = ktime_get_real();
 
                        opt = IPV6_PMTUDISC_DO;
                        kernel_setsockopt(conn->params.local->socket,
@@ -515,3 +524,51 @@ void rxrpc_reject_packets(struct rxrpc_local *local)
 
        _leave("");
 }
+
+/*
+ * Send a VERSION reply to a peer as a keepalive.
+ */
+void rxrpc_send_keepalive(struct rxrpc_peer *peer)
+{
+       struct rxrpc_wire_header whdr;
+       struct msghdr msg;
+       struct kvec iov[2];
+       size_t len;
+       int ret;
+
+       _enter("");
+
+       msg.msg_name    = &peer->srx.transport;
+       msg.msg_namelen = peer->srx.transport_len;
+       msg.msg_control = NULL;
+       msg.msg_controllen = 0;
+       msg.msg_flags   = 0;
+
+       whdr.epoch      = htonl(peer->local->rxnet->epoch);
+       whdr.cid        = 0;
+       whdr.callNumber = 0;
+       whdr.seq        = 0;
+       whdr.serial     = 0;
+       whdr.type       = RXRPC_PACKET_TYPE_VERSION; /* Not client-initiated */
+       whdr.flags      = RXRPC_LAST_PACKET;
+       whdr.userStatus = 0;
+       whdr.securityIndex = 0;
+       whdr._rsvd      = 0;
+       whdr.serviceId  = 0;
+
+       iov[0].iov_base = &whdr;
+       iov[0].iov_len  = sizeof(whdr);
+       iov[1].iov_base = (char *)rxrpc_keepalive_string;
+       iov[1].iov_len  = sizeof(rxrpc_keepalive_string);
+
+       len = iov[0].iov_len + iov[1].iov_len;
+
+       _proto("Tx VERSION (keepalive)");
+
+       ret = kernel_sendmsg(peer->local->socket, &msg, iov, 2, len);
+       if (ret < 0)
+               _debug("sendmsg failed: %d", ret);
+
+       peer->last_tx_at = ktime_get_real();
+       _leave("");
+}

diff --git a/net/rxrpc/peer_event.c b/net/rxrpc/peer_event.c
index 7f749505e699a0ac5d8e04f832f21629643a55d0..d01eb9a064487ebf5f9ebe0b644f7dbacec5f75a 100644 (file)
--- a/net/rxrpc/peer_event.c
+++ b/net/rxrpc/peer_event.c
@@ -348,3 +348,99 @@ void rxrpc_peer_add_rtt(struct rxrpc_call *call, enum rxrpc_rtt_rx_trace why,
        trace_rxrpc_rtt_rx(call, why, send_serial, resp_serial, rtt,
                           usage, avg);
 }
+
+/*
+ * Perform keep-alive pings with VERSION packets to keep any NAT alive.
+ */
+void rxrpc_peer_keepalive_worker(struct work_struct *work)
+{
+       struct rxrpc_net *rxnet =
+               container_of(work, struct rxrpc_net, peer_keepalive_work);
+       struct rxrpc_peer *peer;
+       unsigned long delay;
+       ktime_t base, now = ktime_get_real();
+       s64 diff;
+       u8 cursor, slot;
+
+       base = rxnet->peer_keepalive_base;
+       cursor = rxnet->peer_keepalive_cursor;
+
+       _enter("%u,%lld", cursor, ktime_sub(now, base));
+
+next_bucket:
+       diff = ktime_to_ns(ktime_sub(now, base));
+       if (diff < 0)
+               goto resched;
+
+       _debug("at %u", cursor);
+       spin_lock_bh(&rxnet->peer_hash_lock);
+next_peer:
+       if (!rxnet->live) {
+               spin_unlock_bh(&rxnet->peer_hash_lock);
+               goto out;
+       }
+
+       /* Everything in the bucket at the cursor is processed this second; the
+        * bucket at cursor + 1 goes now + 1s and so on...
+        */
+       if (hlist_empty(&rxnet->peer_keepalive[cursor])) {
+               if (hlist_empty(&rxnet->peer_keepalive_new)) {
+                       spin_unlock_bh(&rxnet->peer_hash_lock);
+                       goto emptied_bucket;
+               }
+
+               hlist_move_list(&rxnet->peer_keepalive_new,
+                               &rxnet->peer_keepalive[cursor]);
+       }
+
+       peer = hlist_entry(rxnet->peer_keepalive[cursor].first,
+                          struct rxrpc_peer, keepalive_link);
+       hlist_del_init(&peer->keepalive_link);
+       if (!rxrpc_get_peer_maybe(peer))
+               goto next_peer;
+
+       spin_unlock_bh(&rxnet->peer_hash_lock);
+
+       _debug("peer %u {%pISp}", peer->debug_id, &peer->srx.transport);
+
+recalc:
+       diff = ktime_divns(ktime_sub(peer->last_tx_at, base), NSEC_PER_SEC);
+       if (diff < -30 || diff > 30)
+               goto send; /* LSW of 64-bit time probably wrapped on 32-bit */
+       diff += RXRPC_KEEPALIVE_TIME - 1;
+       if (diff < 0)
+               goto send;
+
+       slot = (diff > RXRPC_KEEPALIVE_TIME - 1) ? RXRPC_KEEPALIVE_TIME - 1 : diff;
+       if (slot == 0)
+               goto send;
+
+       /* A transmission to this peer occurred since last we examined it so
+        * put it into the appropriate future bucket.
+        */
+       slot = (slot + cursor) % ARRAY_SIZE(rxnet->peer_keepalive);
+       spin_lock_bh(&rxnet->peer_hash_lock);
+       hlist_add_head(&peer->keepalive_link, &rxnet->peer_keepalive[slot]);
+       rxrpc_put_peer(peer);
+       goto next_peer;
+
+send:
+       rxrpc_send_keepalive(peer);
+       now = ktime_get_real();
+       goto recalc;
+
+emptied_bucket:
+       cursor++;
+       if (cursor >= ARRAY_SIZE(rxnet->peer_keepalive))
+               cursor = 0;
+       base = ktime_add_ns(base, NSEC_PER_SEC);
+       goto next_bucket;
+
+resched:
+       rxnet->peer_keepalive_base = base;
+       rxnet->peer_keepalive_cursor = cursor;
+       delay = nsecs_to_jiffies(-diff) + 1;
+       timer_reduce(&rxnet->peer_keepalive_timer, jiffies + delay);
+out:
+       _leave("");
+}

diff --git a/net/rxrpc/peer_object.c b/net/rxrpc/peer_object.c
index d02a99f37f5f49c038d857e99f6ae408dfc7b79a..94a6dbfcf1296f2d3ae7efb78c5966b1f69f84d2 100644 (file)
--- a/net/rxrpc/peer_object.c
+++ b/net/rxrpc/peer_object.c
@@ -322,6 +322,7 @@ struct rxrpc_peer *rxrpc_lookup_incoming_peer(struct rxrpc_local *local,
        if (!peer) {
                peer = prealloc;
                hash_add_rcu(rxnet->peer_hash, &peer->hash_link, hash_key);
+               hlist_add_head(&peer->keepalive_link, &rxnet->peer_keepalive_new);
        }
 
        spin_unlock(&rxnet->peer_hash_lock);
@@ -363,9 +364,12 @@ struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_local *local,
                peer = __rxrpc_lookup_peer_rcu(local, srx, hash_key);
                if (peer && !rxrpc_get_peer_maybe(peer))
                        peer = NULL;
-               if (!peer)
+               if (!peer) {
                        hash_add_rcu(rxnet->peer_hash,
                                     &candidate->hash_link, hash_key);
+                       hlist_add_head(&candidate->keepalive_link,
+                                      &rxnet->peer_keepalive_new);
+               }
 
                spin_unlock_bh(&rxnet->peer_hash_lock);
 
@@ -392,6 +396,7 @@ void __rxrpc_put_peer(struct rxrpc_peer *peer)
 
        spin_lock_bh(&rxnet->peer_hash_lock);
        hash_del_rcu(&peer->hash_link);
+       hlist_del_init(&peer->keepalive_link);
        spin_unlock_bh(&rxnet->peer_hash_lock);
 
        kfree_rcu(peer, rcu);

diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 77cb23c7bd0a8421c4290dfc5a61d18ff1b82a40..588fea0dd3627e5ea6515963d9eabebca603831e 100644 (file)
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -668,6 +668,7 @@ static int rxkad_issue_challenge(struct rxrpc_connection *conn)
                return -EAGAIN;
        }
 
+       conn->params.peer->last_tx_at = ktime_get_real();
        _leave(" = 0");
        return 0;
 }
@@ -722,6 +723,7 @@ static int rxkad_send_response(struct rxrpc_connection *conn,
                return -EAGAIN;
        }
 
+       conn->params.peer->last_tx_at = ktime_get_real();
        _leave(" = 0");
        return 0;
 }