rxrpc: Fix warning by splitting rxrpc_send_call_packet()

Split rxrpc_send_data_packet() to separate ACK generation (which is more
complicated) from ABORT generation.  This simplifies the code a bit and
fixes the following warning:

In file included from ../net/rxrpc/output.c:20:0:
net/rxrpc/output.c: In function 'rxrpc_send_call_packet':
net/rxrpc/ar-internal.h:1187:27: error: 'top' may be used uninitialized in this function [-Werror=maybe-uninitialized]
net/rxrpc/output.c:103:24: note: 'top' was declared here
net/rxrpc/output.c:225:25: error: 'hard_ack' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Howells <dhowells@redhat.com>

8 files changed, 102 insertions, 84 deletions

diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 4954e6e25819..ef849a12a0f0 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -1068,7 +1068,8 @@ extern const s8 rxrpc_ack_priority[];
 /*
  * output.c
  */
-int rxrpc_send_call_packet(struct rxrpc_call *, u8);
+int rxrpc_send_ack_packet(struct rxrpc_call *);
+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 *);
 
diff --git a/net/rxrpc/call_accept.c b/net/rxrpc/call_accept.c
index 22cd8a18c481..832d854c2d5c 100644
--- a/net/rxrpc/call_accept.c
+++ b/net/rxrpc/call_accept.c
@@ -565,7 +565,7 @@ out_discard:
         write_unlock_bh(&call->state_lock);
         write_unlock(&rx->call_lock);
         if (abort) {
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+                rxrpc_send_abort_packet(call);
                 rxrpc_release_call(rx, call);
                 rxrpc_put_call(call, rxrpc_call_put);
         }
diff --git a/net/rxrpc/call_event.c b/net/rxrpc/call_event.c
index 4f00476630b9..e313099860d5 100644
--- a/net/rxrpc/call_event.c
+++ b/net/rxrpc/call_event.c
@@ -253,7 +253,7 @@ static void rxrpc_resend(struct rxrpc_call *call, ktime_t now)
                         goto out;
                 rxrpc_propose_ACK(call, RXRPC_ACK_PING, 0, 0, true, false,
                                   rxrpc_propose_ack_ping_for_lost_ack);
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+                rxrpc_send_ack_packet(call);
                 goto out;
         }
 
@@ -328,7 +328,7 @@ void rxrpc_process_call(struct work_struct *work)
 
 recheck_state:
         if (test_and_clear_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+                rxrpc_send_abort_packet(call);
                 goto recheck_state;
         }
 
@@ -347,7 +347,7 @@ recheck_state:
         if (test_and_clear_bit(RXRPC_CALL_EV_ACK, &call->events)) {
                 call->ack_at = call->expire_at;
                 if (call->ackr_reason) {
-                        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+                        rxrpc_send_ack_packet(call);
                         goto recheck_state;
                 }
         }
diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c
index 364b42dc3dce..07094012ac15 100644
--- a/net/rxrpc/call_object.c
+++ b/net/rxrpc/call_object.c
@@ -498,7 +498,7 @@ void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
                                   struct rxrpc_call, sock_link);
                 rxrpc_get_call(call, rxrpc_call_got);
                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+                rxrpc_send_abort_packet(call);
                 rxrpc_release_call(rx, call);
                 rxrpc_put_call(call, rxrpc_call_put);
         }
diff --git a/net/rxrpc/output.c b/net/rxrpc/output.c
index 0d47db886f6e..2dae877c0876 100644
--- a/net/rxrpc/output.c
+++ b/net/rxrpc/output.c
@@ -19,24 +19,24 @@
 #include <net/af_rxrpc.h>
 #include "ar-internal.h"
 
-struct rxrpc_pkt_buffer {
+struct rxrpc_ack_buffer {
         struct rxrpc_wire_header whdr;
-        union {
-                struct {
-                        struct rxrpc_ackpacket ack;
-                        u8 acks[255];
-                        u8 pad[3];
-                };
-                __be32 abort_code;
-        };
+        struct rxrpc_ackpacket ack;
+        u8 acks[255];
+        u8 pad[3];
         struct rxrpc_ackinfo ackinfo;
 };
 
+struct rxrpc_abort_buffer {
+        struct rxrpc_wire_header whdr;
+        __be32 abort_code;
+};
+
 /*
  * Fill out an ACK packet.
  */
 static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
-                                 struct rxrpc_pkt_buffer *pkt,
+                                 struct rxrpc_ack_buffer *pkt,
                                  rxrpc_seq_t *_hard_ack,
                                  rxrpc_seq_t *_top)
 {
@@ -91,22 +91,19 @@ static size_t rxrpc_fill_out_ack(struct rxrpc_call *call,
 }
 
 /*
- * Send an ACK or ABORT call packet.
+ * Send an ACK call packet.
  */
-int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
+int rxrpc_send_ack_packet(struct rxrpc_call *call)
 {
         struct rxrpc_connection *conn = NULL;
-        struct rxrpc_pkt_buffer *pkt;
+        struct rxrpc_ack_buffer *pkt;
         struct msghdr msg;
         struct kvec iov[2];
         rxrpc_serial_t serial;
         rxrpc_seq_t hard_ack, top;
         size_t len, n;
         bool ping = false;
-        int ioc, ret;
-        u32 abort_code;
-
-        _enter("%u,%s", call->debug_id, rxrpc_pkts[type]);
+        int ret;
 
         spin_lock_bh(&call->lock);
         if (call->conn)
@@ -131,65 +128,37 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
         pkt->whdr.cid           = htonl(call->cid);
         pkt->whdr.callNumber    = htonl(call->call_id);
         pkt->whdr.seq           = 0;
-        pkt->whdr.type          = type;
-        pkt->whdr.flags         = conn->out_clientflag;
+        pkt->whdr.type          = RXRPC_PACKET_TYPE_ACK;
+        pkt->whdr.flags         = RXRPC_SLOW_START_OK | conn->out_clientflag;
         pkt->whdr.userStatus    = 0;
         pkt->whdr.securityIndex = call->security_ix;
         pkt->whdr._rsvd         = 0;
         pkt->whdr.serviceId     = htons(call->service_id);
 
-        iov[0].iov_base = pkt;
-        iov[0].iov_len  = sizeof(pkt->whdr);
-        len = sizeof(pkt->whdr);
-
-        switch (type) {
-        case RXRPC_PACKET_TYPE_ACK:
-                spin_lock_bh(&call->lock);
-                if (!call->ackr_reason) {
-                        spin_unlock_bh(&call->lock);
-                        ret = 0;
-                        goto out;
-                }
-                ping = (call->ackr_reason == RXRPC_ACK_PING);
-                n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
-                call->ackr_reason = 0;
-
+        spin_lock_bh(&call->lock);
+        if (!call->ackr_reason) {
                 spin_unlock_bh(&call->lock);
-
-
-                pkt->whdr.flags |= RXRPC_SLOW_START_OK;
-
-                iov[0].iov_len += sizeof(pkt->ack) + n;
-                iov[1].iov_base = &pkt->ackinfo;
-                iov[1].iov_len  = sizeof(pkt->ackinfo);
-                len += sizeof(pkt->ack) + n + sizeof(pkt->ackinfo);
-                ioc = 2;
-                break;
-
-        case RXRPC_PACKET_TYPE_ABORT:
-                abort_code = call->abort_code;
-                pkt->abort_code = htonl(abort_code);
-                iov[0].iov_len += sizeof(pkt->abort_code);
-                len += sizeof(pkt->abort_code);
-                ioc = 1;
-                break;
-
-        default:
-                BUG();
-                ret = -ENOANO;
+                ret = 0;
                 goto out;
         }
+        ping = (call->ackr_reason == RXRPC_ACK_PING);
+        n = rxrpc_fill_out_ack(call, pkt, &hard_ack, &top);
+        call->ackr_reason = 0;
+
+        spin_unlock_bh(&call->lock);
+
+        iov[0].iov_base = pkt;
+        iov[0].iov_len  = sizeof(pkt->whdr) + sizeof(pkt->ack) + n;
+        iov[1].iov_base = &pkt->ackinfo;
+        iov[1].iov_len  = sizeof(pkt->ackinfo);
+        len = iov[0].iov_len + iov[1].iov_len;
 
         serial = atomic_inc_return(&conn->serial);
         pkt->whdr.serial = htonl(serial);
-        switch (type) {
-        case RXRPC_PACKET_TYPE_ACK:
-                trace_rxrpc_tx_ack(call, serial,
-                                   ntohl(pkt->ack.firstPacket),
-                                   ntohl(pkt->ack.serial),
-                                   pkt->ack.reason, pkt->ack.nAcks);
-                break;
-        }
+        trace_rxrpc_tx_ack(call, serial,
+                           ntohl(pkt->ack.firstPacket),
+                           ntohl(pkt->ack.serial),
+                           pkt->ack.reason, pkt->ack.nAcks);
 
         if (ping) {
                 call->ackr_ping = serial;
@@ -205,13 +174,12 @@ int rxrpc_send_call_packet(struct rxrpc_call *call, u8 type)
                 set_bit(RXRPC_CALL_PINGING, &call->flags);
                 trace_rxrpc_rtt_tx(call, rxrpc_rtt_tx_ping, serial);
         }
-        ret = kernel_sendmsg(conn->params.local->socket,
-                             &msg, iov, ioc, len);
+
+        ret = kernel_sendmsg(conn->params.local->socket, &msg, iov, 2, len);
         if (ping)
                 call->ackr_ping_time = ktime_get_real();
 
-        if (type == RXRPC_PACKET_TYPE_ACK &&
-            call->state < RXRPC_CALL_COMPLETE) {
+        if (call->state < RXRPC_CALL_COMPLETE) {
                 if (ret < 0) {
                         clear_bit(RXRPC_CALL_PINGING, &call->flags);
                         rxrpc_propose_ACK(call, pkt->ack.reason,
@@ -236,6 +204,56 @@ out:
 }
 
 /*
+ * Send an ABORT call packet.
+ */
+int rxrpc_send_abort_packet(struct rxrpc_call *call)
+{
+        struct rxrpc_connection *conn = NULL;
+        struct rxrpc_abort_buffer pkt;
+        struct msghdr msg;
+        struct kvec iov[1];
+        rxrpc_serial_t serial;
+        int ret;
+
+        spin_lock_bh(&call->lock);
+        if (call->conn)
+                conn = rxrpc_get_connection_maybe(call->conn);
+        spin_unlock_bh(&call->lock);
+        if (!conn)
+                return -ECONNRESET;
+
+        msg.msg_name    = &call->peer->srx.transport;
+        msg.msg_namelen = call->peer->srx.transport_len;
+        msg.msg_control = NULL;
+        msg.msg_controllen = 0;
+        msg.msg_flags   = 0;
+
+        pkt.whdr.epoch          = htonl(conn->proto.epoch);
+        pkt.whdr.cid            = htonl(call->cid);
+        pkt.whdr.callNumber     = htonl(call->call_id);
+        pkt.whdr.seq            = 0;
+        pkt.whdr.type           = RXRPC_PACKET_TYPE_ABORT;
+        pkt.whdr.flags          = conn->out_clientflag;
+        pkt.whdr.userStatus     = 0;
+        pkt.whdr.securityIndex  = call->security_ix;
+        pkt.whdr._rsvd          = 0;
+        pkt.whdr.serviceId      = htons(call->service_id);
+        pkt.abort_code          = htonl(call->abort_code);
+
+        iov[0].iov_base = &pkt;
+        iov[0].iov_len  = sizeof(pkt);
+
+        serial = atomic_inc_return(&conn->serial);
+        pkt.whdr.serial = htonl(serial);
+
+        ret = kernel_sendmsg(conn->params.local->socket,
+                             &msg, iov, 1, sizeof(pkt));
+
+        rxrpc_put_connection(conn);
+        return ret;
+}
+
+/*
  * send a packet through the transport endpoint
  */
 int rxrpc_send_data_packet(struct rxrpc_call *call, struct sk_buff *skb,
diff --git a/net/rxrpc/recvmsg.c b/net/rxrpc/recvmsg.c
index f05ea0a88076..11723bc1c783 100644
--- a/net/rxrpc/recvmsg.c
+++ b/net/rxrpc/recvmsg.c
@@ -143,7 +143,7 @@ static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
         if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) {
                 rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, true, false,
                                   rxrpc_propose_ack_terminal_ack);
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+                rxrpc_send_ack_packet(call);
         }
 
         write_lock_bh(&call->state_lock);
@@ -212,7 +212,7 @@ static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
                                           true, false,
                                           rxrpc_propose_ack_rotate_rx);
                 if (call->ackr_reason)
-                        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+                        rxrpc_send_ack_packet(call);
         }
 }
 
diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c
index 627abed5f999..4374e7b9c7bf 100644
--- a/net/rxrpc/rxkad.c
+++ b/net/rxrpc/rxkad.c
@@ -381,7 +381,7 @@ static int rxkad_verify_packet_1(struct rxrpc_call *call, struct sk_buff *skb,
         return 0;
 
 protocol_error:
-        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+        rxrpc_send_abort_packet(call);
         _leave(" = -EPROTO");
         return -EPROTO;
 
@@ -471,7 +471,7 @@ static int rxkad_verify_packet_2(struct rxrpc_call *call, struct sk_buff *skb,
         return 0;
 
 protocol_error:
-        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+        rxrpc_send_abort_packet(call);
         _leave(" = -EPROTO");
         return -EPROTO;
 
@@ -523,7 +523,7 @@ static int rxkad_verify_packet(struct rxrpc_call *call, struct sk_buff *skb,
 
         if (cksum != expected_cksum) {
                 rxrpc_abort_call("VCK", call, seq, RXKADSEALEDINCON, EPROTO);
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+                rxrpc_send_abort_packet(call);
                 _leave(" = -EPROTO [csum failed]");
                 return -EPROTO;
         }
diff --git a/net/rxrpc/sendmsg.c b/net/rxrpc/sendmsg.c
index 3322543d460a..901b28ceeff4 100644
--- a/net/rxrpc/sendmsg.c
+++ b/net/rxrpc/sendmsg.c
@@ -197,7 +197,7 @@ static int rxrpc_send_data(struct rxrpc_sock *rx,
         do {
                 /* Check to see if there's a ping ACK to reply to. */
                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
-                        rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ACK);
+                        rxrpc_send_ack_packet(call);
 
                 if (!skb) {
                         size_t size, chunk, max, space;
@@ -514,8 +514,7 @@ int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
         } else if (cmd == RXRPC_CMD_SEND_ABORT) {
                 ret = 0;
                 if (rxrpc_abort_call("CMD", call, 0, abort_code, ECONNABORTED))
-                        ret = rxrpc_send_call_packet(call,
-                                                     RXRPC_PACKET_TYPE_ABORT);
+                        ret = rxrpc_send_abort_packet(call);
         } else if (cmd != RXRPC_CMD_SEND_DATA) {
                 ret = -EINVAL;
         } else if (rxrpc_is_client_call(call) &&
@@ -597,7 +596,7 @@ void rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
         lock_sock(sock->sk);
 
         if (rxrpc_abort_call(why, call, 0, abort_code, error))
-                rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
+                rxrpc_send_abort_packet(call);
 
         release_sock(sock->sk);
         _leave("");