libmemif: refactor examples

- icmp_responder: responds to ICMPv4 and ARP requests
- loopback: connects two interfaces and sends a
  verification packet from master memif to slave memif
  where it is looped back
- loopback (reverse path): reverses direction of packet
  in loopback application (slave memif to master memif)

Type: refactor

Signed-off-by: Jakub Grajciar <jgrajcia@cisco.com>
Change-Id: Ie90aaa3367269408efb6c5d538ad5aa827432238
Signed-off-by: Dave Wallace <dwallacelf@gmail.com>
diff --git a/extras/libmemif/examples/common/icmp_proto.h b/extras/libmemif/examples/common/icmp_proto.h
new file mode 100644
index 0000000..e346a3b
--- /dev/null
+++ b/extras/libmemif/examples/common/icmp_proto.h
@@ -0,0 +1,48 @@
+/*
+ *------------------------------------------------------------------
+ * Copyright (c) 2017 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *------------------------------------------------------------------
+ */
+
+#ifndef _ICMP_PROTO_H_
+#define _ICMP_PROTO_H_
+
+typedef enum
+{
+  ICMPR_FLOW_MODE_ETH = 0,
+  ICMPR_FLOW_MODE_IP,
+} icmpr_flow_mode_t;
+
+int resolve_packet (void *in_pck, ssize_t in_size, void *out_pck,
+		    uint32_t *out_size, uint8_t ip_addr[4],
+		    uint8_t hw_addr[6]);
+
+/* resolve packet in place */
+int resolve_packet_zero_copy (void *pck, uint32_t *size, uint8_t ip_addr[4],
+			      uint8_t hw_addr[6]);
+
+/* resolve packet in place and add eth encap */
+int resolve_packet_zero_copy_add_encap (void **pck, uint32_t *size,
+					uint8_t ip_addr[4]);
+
+int generate_packet (void *pck, uint32_t *size, uint8_t saddr[4],
+		     uint8_t daddr[4], uint8_t hw_daddr[6], uint32_t seq);
+
+int generate_packet2 (void *pck, uint32_t *size, uint8_t saddr[4],
+		      uint8_t daddr[4], uint8_t hw_daddr[6], uint32_t seq,
+		      icmpr_flow_mode_t);
+
+int print_packet (void *pck);
+
+#endif /* _ICMP_PROTO_H_ */