inany: Add inany_ntop() helper

Add this helper to format an inany into either IPv4 or IPv6 text
format as appropriate.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Makefile

@@ -45,8 +45,8 @@ FLAGS += -DVERSION=\"$(VERSION)\"
 FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS)
 
 PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c icmp.c \
-	igmp.c iov.c isolation.c lineread.c log.c mld.c ndp.c netlink.c \
+	igmp.c inany.c iov.c isolation.c lineread.c log.c mld.c ndp.c \
-	packet.c passt.c pasta.c pcap.c pif.c port_fwd.c tap.c tcp.c \
+	netlink.c packet.c passt.c pasta.c pcap.c pif.c port_fwd.c tap.c tcp.c \
 	tcp_splice.c udp.c util.c
 QRAP_SRCS = qrap.c
 SRCS = $(PASST_SRCS) $(QRAP_SRCS)

inany.c

@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright Red Hat
+ * Author: David Gibson <david@gibson.dropbear.id.au>
+ *
+ * inany.c - Types and helpers for handling addresses which could be
+ *           IPv6 or IPv4 (encoded as IPv4-mapped IPv6 addresses)
+ */
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <assert.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include "util.h"
+#include "siphash.h"
+#include "inany.h"
+
+/** inany_ntop - Convert an IPv[46] address to text format
+ * @src:	IPv[46] address
+ * @dst:	output buffer, minimum INANY_ADDRSTRLEN bytes
+ * @size:	size of buffer at @dst
+ *
+ * Return: On success, a non-null pointer to @dst, NULL on failure
+ */
+/* cppcheck-suppress unusedFunction */
+const char *inany_ntop(const union inany_addr *src, char *dst, socklen_t size)
+{
+	const struct in_addr *v4 = inany_v4(src);
+
+	if (v4)
+		return inet_ntop(AF_INET, v4, dst, size);
+
+	return inet_ntop(AF_INET6, &src->a6, dst, size);
+}

inany.h

@@ -162,4 +162,8 @@ static inline void inany_siphash_feed(struct siphash_state *state,
 	siphash_feed(state, (uint64_t)aa->u32[2] << 32 | aa->u32[3]);
 }
 
+#define INANY_ADDRSTRLEN	MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN)
+
+const char *inany_ntop(const union inany_addr *src, char *dst, socklen_t size);
+
 #endif /* INANY_H */