[PATCH net-next 07/13] rxrpc: Extract the code from a received ABORT packet much earlier

From: David Howells
Date: Wed Nov 23 2022 - 05:22:21 EST


Extract the code from a received rx ABORT packet much earlier and in a
single place and harmonise the responses to malformed ABORT packets.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
cc: Marc Dionne <marc.dionne@xxxxxxxxxxxx>
cc: linux-afs@xxxxxxxxxxxxxxxxxxx
---

net/rxrpc/conn_event.c | 12 +-----------
net/rxrpc/input.c | 31 +++++++++++++++++++------------
2 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/net/rxrpc/conn_event.c b/net/rxrpc/conn_event.c
index 71ed6b9dc63a..f890a30c4df6 100644
--- a/net/rxrpc/conn_event.c
+++ b/net/rxrpc/conn_event.c
@@ -282,8 +282,6 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
u32 *_abort_code)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
- __be32 wtmp;
- u32 abort_code;
int loop, ret;

if (conn->state >= RXRPC_CONN_REMOTELY_ABORTED) {
@@ -305,16 +303,8 @@ static int rxrpc_process_event(struct rxrpc_connection *conn,
return 0;

case RXRPC_PACKET_TYPE_ABORT:
- if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
- &wtmp, sizeof(wtmp)) < 0) {
- trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
- tracepoint_string("bad_abort"));
- return -EPROTO;
- }
- abort_code = ntohl(wtmp);
-
conn->error = -ECONNABORTED;
- conn->abort_code = abort_code;
+ conn->abort_code = skb->priority;
conn->state = RXRPC_CONN_REMOTELY_ABORTED;
set_bit(RXRPC_CONN_DONT_REUSE, &conn->flags);
rxrpc_abort_calls(conn, RXRPC_CALL_REMOTELY_ABORTED, sp->hdr.serial);
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c
index 44caf88e04b8..42c8257158f7 100644
--- a/net/rxrpc/input.c
+++ b/net/rxrpc/input.c
@@ -1019,20 +1019,11 @@ static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
- __be32 wtmp;
- u32 abort_code = RX_CALL_DEAD;
-
- _enter("");
-
- if (skb->len >= 4 &&
- skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
- &wtmp, sizeof(wtmp)) >= 0)
- abort_code = ntohl(wtmp);

- trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
+ trace_rxrpc_rx_abort(call, sp->hdr.serial, skb->priority);

rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
- abort_code, -ECONNABORTED);
+ skb->priority, -ECONNABORTED);
}

/*
@@ -1193,6 +1184,20 @@ int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
return 0;
}

+/*
+ * Extract the abort code from an ABORT packet and stash it in skb->priority.
+ */
+static bool rxrpc_extract_abort(struct sk_buff *skb)
+{
+ __be32 wtmp;
+
+ if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
+ &wtmp, sizeof(wtmp)) < 0)
+ return false;
+ skb->priority = ntohl(wtmp);
+ return true;
+}
+
/*
* handle data received on the local endpoint
* - may be called in interrupt context
@@ -1264,8 +1269,10 @@ int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
case RXRPC_PACKET_TYPE_ACKALL:
if (sp->hdr.callNumber == 0)
goto bad_message;
- fallthrough;
+ break;
case RXRPC_PACKET_TYPE_ABORT:
+ if (!rxrpc_extract_abort(skb))
+ return true; /* Just discard if malformed */
break;

case RXRPC_PACKET_TYPE_DATA: