sandbox: eth: Add support for using the 'lo' interface

The 'lo' interface on Linux doesn't support thinks like ARP or
link-layer access like we use to talk to a normal network interface.
A higher-level network API must be used to access localhost.

As written, this interface is limited to not supporting ICMP since the
API doesn't allow the socket to be opened for all IP traffic and be able
to receive at the same time. UDP is far more useful to test with, so it
was selected over ICMP. Ping won't work, but things like TFTP should
work.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

1 files changed, 9 insertions, 1 deletions

diff --git a/arch/sandbox/include/asm/eth-raw-os.h b/arch/sandbox/include/asm/eth-raw-os.h
index df60c4f3b8c..ed4b2e26499 100644
--- a/arch/sandbox/include/asm/eth-raw-os.h
+++ b/arch/sandbox/include/asm/eth-raw-os.h
@@ -15,16 +15,24 @@
  *
  * sd: socket descriptor - the open socket during a session
  * device: struct sockaddr_ll - the host interface packets move to/from
+ * local: 1 or 0 to select the local interface ('lo') or not
+ * local_bindsd: socket descriptor to prevent the kernel from sending
+ *		 a message to the server claiming the port is
+ *		 unreachable
+ * local_bind_udp_port: The UDP port number that we bound to
  */
 struct eth_sandbox_raw_priv {
 	int sd;
 	void *device;
+	int local;
+	int local_bind_sd;
+	unsigned short local_bind_udp_port;
 };
 
 int sandbox_eth_raw_os_start(const char *ifname, unsigned char *ethmac,
 			    struct eth_sandbox_raw_priv *priv);
 int sandbox_eth_raw_os_send(void *packet, int length,
-			    const struct eth_sandbox_raw_priv *priv);
+			    struct eth_sandbox_raw_priv *priv);
 int sandbox_eth_raw_os_recv(void *packet, int *length,
 			    const struct eth_sandbox_raw_priv *priv);
 void sandbox_eth_raw_os_stop(struct eth_sandbox_raw_priv *priv);