rxrpc: Move peer lookup from call-accept to new-incoming-conn

Move the lookup of a peer from a call that's being accepted into the
function that creates a new incoming connection.  This will allow us to
avoid incrementing the peer's usage count in some cases in future.

Note that I haven't bother to integrate rxrpc_get_addr_from_skb() with
rxrpc_extract_addr_from_skb() as I'm going to delete the former in the very
near future.

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

1 files changed, 32 insertions, 0 deletions

diff --git a/net/rxrpc/utils.c b/net/rxrpc/utils.c
index f28122a15a24..d3db02ecc37f 100644
--- a/net/rxrpc/utils.c
+++ b/net/rxrpc/utils.c
@@ -10,6 +10,7 @@
  */
 
 #include <linux/ip.h>
+#include <linux/ipv6.h>
 #include <linux/udp.h>
 #include "ar-internal.h"
 
@@ -39,3 +40,34 @@ void rxrpc_get_addr_from_skb(struct rxrpc_local *local,
 		BUG();
 	}
 }
+
+/*
+ * Fill out a peer address from a socket buffer containing a packet.
+ */
+int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *srx, struct sk_buff *skb)
+{
+	memset(srx, 0, sizeof(*srx));
+
+	switch (ntohs(skb->protocol)) {
+	case ETH_P_IP:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin);
+		srx->transport.sin.sin_family = AF_INET;
+		srx->transport.sin.sin_port = udp_hdr(skb)->source;
+		srx->transport.sin.sin_addr.s_addr = ip_hdr(skb)->saddr;
+		return 0;
+
+	case ETH_P_IPV6:
+		srx->transport_type = SOCK_DGRAM;
+		srx->transport_len = sizeof(srx->transport.sin6);
+		srx->transport.sin6.sin6_family = AF_INET6;
+		srx->transport.sin6.sin6_port = udp_hdr(skb)->source;
+		srx->transport.sin6.sin6_addr = ipv6_hdr(skb)->saddr;
+		return 0;
+
+	default:
+		pr_warn_ratelimited("AF_RXRPC: Unknown eth protocol %u\n",
+				    ntohs(skb->protocol));
+		return -EAFNOSUPPORT;
+	}
+}