sunrpc: move address copy/cmp/convert routines and prototypes from clnt.h to addr.h

These routines are used by server and client code, so having them in a
separate header would be best.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/include/linux/sunrpc/addr.h b/include/linux/sunrpc/addr.h
new file mode 100644
index 0000000..07d8e53
--- /dev/null
+++ b/include/linux/sunrpc/addr.h
@@ -0,0 +1,170 @@
+/*
+ * linux/include/linux/sunrpc/addr.h
+ *
+ * Various routines for copying and comparing sockaddrs and for
+ * converting them to and from presentation format.
+ */
+#ifndef _LINUX_SUNRPC_ADDR_H
+#define _LINUX_SUNRPC_ADDR_H
+
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/in6.h>
+#include <net/ipv6.h>
+
+size_t		rpc_ntop(const struct sockaddr *, char *, const size_t);
+size_t		rpc_pton(struct net *, const char *, const size_t,
+			 struct sockaddr *, const size_t);
+char *		rpc_sockaddr2uaddr(const struct sockaddr *, gfp_t);
+size_t		rpc_uaddr2sockaddr(struct net *, const char *, const size_t,
+				   struct sockaddr *, const size_t);
+
+static inline unsigned short rpc_get_port(const struct sockaddr *sap)
+{
+	switch (sap->sa_family) {
+	case AF_INET:
+		return ntohs(((struct sockaddr_in *)sap)->sin_port);
+	case AF_INET6:
+		return ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
+	}
+	return 0;
+}
+
+static inline void rpc_set_port(struct sockaddr *sap,
+				const unsigned short port)
+{
+	switch (sap->sa_family) {
+	case AF_INET:
+		((struct sockaddr_in *)sap)->sin_port = htons(port);
+		break;
+	case AF_INET6:
+		((struct sockaddr_in6 *)sap)->sin6_port = htons(port);
+		break;
+	}
+}
+
+#define IPV6_SCOPE_DELIMITER		'%'
+#define IPV6_SCOPE_ID_LEN		sizeof("%nnnnnnnnnn")
+
+static inline bool __rpc_cmp_addr4(const struct sockaddr *sap1,
+				   const struct sockaddr *sap2)
+{
+	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sap1;
+	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sap2;
+
+	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
+}
+
+static inline bool __rpc_copy_addr4(struct sockaddr *dst,
+				    const struct sockaddr *src)
+{
+	const struct sockaddr_in *ssin = (struct sockaddr_in *) src;
+	struct sockaddr_in *dsin = (struct sockaddr_in *) dst;
+
+	dsin->sin_family = ssin->sin_family;
+	dsin->sin_addr.s_addr = ssin->sin_addr.s_addr;
+	return true;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static inline bool __rpc_cmp_addr6(const struct sockaddr *sap1,
+				   const struct sockaddr *sap2)
+{
+	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sap1;
+	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sap2;
+
+	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
+		return false;
+	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
+		return sin1->sin6_scope_id == sin2->sin6_scope_id;
+
+	return true;
+}
+
+static inline bool __rpc_copy_addr6(struct sockaddr *dst,
+				    const struct sockaddr *src)
+{
+	const struct sockaddr_in6 *ssin6 = (const struct sockaddr_in6 *) src;
+	struct sockaddr_in6 *dsin6 = (struct sockaddr_in6 *) dst;
+
+	dsin6->sin6_family = ssin6->sin6_family;
+	dsin6->sin6_addr = ssin6->sin6_addr;
+	dsin6->sin6_scope_id = ssin6->sin6_scope_id;
+	return true;
+}
+#else	/* !(IS_ENABLED(CONFIG_IPV6) */
+static inline bool __rpc_cmp_addr6(const struct sockaddr *sap1,
+				   const struct sockaddr *sap2)
+{
+	return false;
+}
+
+static inline bool __rpc_copy_addr6(struct sockaddr *dst,
+				    const struct sockaddr *src)
+{
+	return false;
+}
+#endif	/* !(IS_ENABLED(CONFIG_IPV6) */
+
+/**
+ * rpc_cmp_addr - compare the address portion of two sockaddrs.
+ * @sap1: first sockaddr
+ * @sap2: second sockaddr
+ *
+ * Just compares the family and address portion. Ignores port, but
+ * compares the scope if it's a link-local address.
+ *
+ * Returns true if the addrs are equal, false if they aren't.
+ */
+static inline bool rpc_cmp_addr(const struct sockaddr *sap1,
+				const struct sockaddr *sap2)
+{
+	if (sap1->sa_family == sap2->sa_family) {
+		switch (sap1->sa_family) {
+		case AF_INET:
+			return __rpc_cmp_addr4(sap1, sap2);
+		case AF_INET6:
+			return __rpc_cmp_addr6(sap1, sap2);
+		}
+	}
+	return false;
+}
+
+/**
+ * rpc_copy_addr - copy the address portion of one sockaddr to another
+ * @dst: destination sockaddr
+ * @src: source sockaddr
+ *
+ * Just copies the address portion and family. Ignores port, scope, etc.
+ * Caller is responsible for making certain that dst is large enough to hold
+ * the address in src. Returns true if address family is supported. Returns
+ * false otherwise.
+ */
+static inline bool rpc_copy_addr(struct sockaddr *dst,
+				 const struct sockaddr *src)
+{
+	switch (src->sa_family) {
+	case AF_INET:
+		return __rpc_copy_addr4(dst, src);
+	case AF_INET6:
+		return __rpc_copy_addr6(dst, src);
+	}
+	return false;
+}
+
+/**
+ * rpc_get_scope_id - return scopeid for a given sockaddr
+ * @sa: sockaddr to get scopeid from
+ *
+ * Returns the value of the sin6_scope_id for AF_INET6 addrs, or 0 if
+ * not an AF_INET6 address.
+ */
+static inline u32 rpc_get_scope_id(const struct sockaddr *sa)
+{
+	if (sa->sa_family != AF_INET6)
+		return 0;
+
+	return ((struct sockaddr_in6 *) sa)->sin6_scope_id;
+}
+
+#endif /* _LINUX_SUNRPC_ADDR_H */