SUNRPC: Move universal address definitions to global header

Universal addresses are defined in RFC 1833 and clarified in RFC 3530.  We
need to use them in several places in the NFS and RPC clients, so move the
relevant definition and block comment to an appropriate global include
file.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/include/linux/sunrpc/msg_prot.h b/include/linux/sunrpc/msg_prot.h
index c4beb5775111..70df4f1d8847 100644
--- a/include/linux/sunrpc/msg_prot.h
+++ b/include/linux/sunrpc/msg_prot.h
@@ -152,5 +152,44 @@ typedef __be32	rpc_fraghdr;
  */
 #define RPCBIND_MAXNETIDLEN     (4u)
 
+/*
+ * Universal addresses are introduced in RFC 1833 and further spelled
+ * out in RFC 3530.  RPCBIND_MAXUADDRLEN defines a maximum byte length
+ * of a universal address for use in allocating buffers and character
+ * arrays.
+ *
+ * Quoting RFC 3530, section 2.2:
+ *
+ * For TCP over IPv4 and for UDP over IPv4, the format of r_addr is the
+ * US-ASCII string:
+ *
+ *      h1.h2.h3.h4.p1.p2
+ *
+ * The prefix, "h1.h2.h3.h4", is the standard textual form for
+ * representing an IPv4 address, which is always four octets long.
+ * Assuming big-endian ordering, h1, h2, h3, and h4, are respectively,
+ * the first through fourth octets each converted to ASCII-decimal.
+ * Assuming big-endian ordering, p1 and p2 are, respectively, the first
+ * and second octets each converted to ASCII-decimal.  For example, if a
+ * host, in big-endian order, has an address of 0x0A010307 and there is
+ * a service listening on, in big endian order, port 0x020F (decimal
+ * 527), then the complete universal address is "10.1.3.7.2.15".
+ *
+ * ...
+ *
+ * For TCP over IPv6 and for UDP over IPv6, the format of r_addr is the
+ * US-ASCII string:
+ *
+ *      x1:x2:x3:x4:x5:x6:x7:x8.p1.p2
+ *
+ * The suffix "p1.p2" is the service port, and is computed the same way
+ * as with universal addresses for TCP and UDP over IPv4.  The prefix,
+ * "x1:x2:x3:x4:x5:x6:x7:x8", is the standard textual form for
+ * representing an IPv6 address as defined in Section 2.2 of [RFC2373].
+ * Additionally, the two alternative forms specified in Section 2.2 of
+ * [RFC2373] are also acceptable.
+ */
+#define RPCBIND_MAXUADDRLEN     (56u)
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_SUNRPC_MSGPROT_H_ */