sandbox: eth-raw: Add a SIMPLE_BUS to enumerate host interfaces

Ask the OS for each of its interfaces and for each one, bind a U-Boot
device and then probe it. This will allocate the priv data structure
that is then populated.

Signed-off-by: Joe Hershberger <joe.hershberger@ni.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/sandbox/include/asm/eth-raw-os.h b/arch/sandbox/include/asm/eth-raw-os.h
index 99f674e..0b511db 100644
--- a/arch/sandbox/include/asm/eth-raw-os.h
+++ b/arch/sandbox/include/asm/eth-raw-os.h
@@ -34,6 +34,17 @@
 	unsigned short local_bind_udp_port;
 };
 
+/* A struct to mimic if_nameindex but that does not depend on Linux headers */
+struct sandbox_eth_raw_if_nameindex {
+	unsigned int if_index; /* Index of interface (1, 2, ...) */
+	char        *if_name;  /* Null-terminated name ("eth0", etc.) */
+};
+
+/* Enumerate host network interfaces */
+struct sandbox_eth_raw_if_nameindex *sandbox_eth_raw_if_nameindex(void);
+/* Free the data structure of enumerated network interfaces */
+void sandbox_eth_raw_if_freenameindex(struct sandbox_eth_raw_if_nameindex *ptr);
+
 /*
  * Check if the interface named "ifname" is a localhost interface or not.
  * ifname - the interface name on the host to check