Commit fb46f6ee authored by David Howells's avatar David Howells
Browse files

rxrpc: Trace protocol errors in received packets 



Add a tracepoint (rxrpc_rx_proto) to record protocol errors in received
packets.  The following changes are made:

 (1) Add a function, __rxrpc_abort_eproto(), to note a protocol error on a
     call and mark the call aborted.  This is wrapped by
     rxrpc_abort_eproto() that makes the why string usable in trace.

 (2) Add trace_rxrpc_rx_proto() or rxrpc_abort_eproto() to protocol error
     generation points, replacing rxrpc_abort_call() with the latter.

 (3) Only send an abort packet in rxkad_verify_packet*() if we actually
     managed to abort the call.

Note that a trace event is also emitted if a kernel user (e.g. afs) tries
to send data through a call when it's not in the transmission phase, though
it's not technically a receive event.

Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
parent ef68622d

include/trace/events/rxrpc.h

+24 −0
Original line number Diff line number Diff line
@@ -1087,6 +1087,30 @@ TRACE_EVENT(rxrpc_improper_term, 
		      __entry->abort_code)

	    );



TRACE_EVENT(rxrpc_rx_eproto,

	    TP_PROTO(struct rxrpc_call *call, rxrpc_serial_t serial,

		     const char *why),



	    TP_ARGS(call, serial, why),



	    TP_STRUCT__entry(

		    __field(struct rxrpc_call *,	call		)

		    __field(rxrpc_serial_t,		serial		)

		    __field(const char *,		why		)

			     ),



	    TP_fast_assign(

		    __entry->call = call;

		    __entry->serial = serial;

		    __entry->why = why;

			   ),



	    TP_printk("c=%p EPROTO %08x %s",

		      __entry->call,

		      __entry->serial,

		      __entry->why)

	    );



#endif /* _TRACE_RXRPC_H */



/* This part must be outside protection */

net/rxrpc/ar-internal.h

+19 −0
Original line number Diff line number Diff line
@@ -739,6 +739,25 @@ static inline bool rxrpc_abort_call(const char *why, struct rxrpc_call *call, 
	return ret;

}



/*

 * Abort a call due to a protocol error.

 */

static inline bool __rxrpc_abort_eproto(struct rxrpc_call *call,

					struct sk_buff *skb,

					const char *eproto_why,

					const char *why,

					u32 abort_code)

{

	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);



	trace_rxrpc_rx_eproto(call, sp->hdr.serial, eproto_why);

	return rxrpc_abort_call(why, call, sp->hdr.seq, abort_code, -EPROTO);

}



#define rxrpc_abort_eproto(call, skb, eproto_why, abort_why, abort_code) \

	__rxrpc_abort_eproto((call), (skb), tracepoint_string(eproto_why), \

			     (abort_why), (abort_code))



/*

 * conn_client.c

 */

net/rxrpc/conn_event.c

+6 −3
Original line number Diff line number Diff line
@@ -281,8 +281,11 @@ static int rxrpc_process_event(struct rxrpc_connection *conn, 


	case RXRPC_PACKET_TYPE_ABORT:

		if (skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),

				  &wtmp, sizeof(wtmp)) < 0)

				  &wtmp, sizeof(wtmp)) < 0) {

			trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,

					      tracepoint_string("bad_abort"));

			return -EPROTO;

		}

		abort_code = ntohl(wtmp);

		_proto("Rx ABORT %%%u { ac=%d }", sp->hdr.serial, abort_code);
@@ -327,7 +330,8 @@ static int rxrpc_process_event(struct rxrpc_connection *conn, 
		return 0;



	default:

		_leave(" = -EPROTO [%u]", sp->hdr.type);

		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,

				      tracepoint_string("bad_conn_pkt"));

		return -EPROTO;

	}

}
@@ -422,6 +426,5 @@ protocol_error: 
	if (rxrpc_abort_connection(conn, ret, abort_code) < 0)

		goto requeue_and_leave;

	rxrpc_free_skb(skb, rxrpc_skb_rx_freed);

	_leave(" [EPROTO]");

	goto out;

}

net/rxrpc/input.c

+4 −1
Original line number Diff line number Diff line
@@ -1017,8 +1017,11 @@ int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb) 
	struct rxrpc_wire_header whdr;



	/* dig out the RxRPC connection details */

	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0)

	if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {

		trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,

				      tracepoint_string("bad_hdr"));

		return -EBADMSG;

	}



	memset(sp, 0, sizeof(*sp));

	sp->hdr.epoch		= ntohl(whdr.epoch);

net/rxrpc/insecure.c

+8 −2
Original line number Diff line number Diff line
@@ -46,7 +46,10 @@ static int none_respond_to_challenge(struct rxrpc_connection *conn, 
				     struct sk_buff *skb,

				     u32 *_abort_code)

{

	*_abort_code = RX_PROTOCOL_ERROR;

	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);



	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,

			      tracepoint_string("chall_none"));

	return -EPROTO;

}
@@ -54,7 +57,10 @@ static int none_verify_response(struct rxrpc_connection *conn, 
				struct sk_buff *skb,

				u32 *_abort_code)

{

	*_abort_code = RX_PROTOCOL_ERROR;

	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);



	trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,

			      tracepoint_string("resp_none"));

	return -EPROTO;

}

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