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Commit 2c7eb0b2 authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
Browse files

SUNRPC: Register both netids for AF_INET6 servers 



TI-RPC is a user-space library of RPC functions that replaces ONC RPC
and allows RPC to operate in the new world of IPv6.

TI-RPC combines the concept of a transport protocol (UDP and TCP)
and a protocol family (PF_INET and PF_INET6) into a single identifier
called a "netid."  For example, "udp" means UDP over IPv4, and "udp6"
means UDP over IPv6.

For rpcbind, then, the RPC service tuple that is registered and
advertised is:

  [RPC program, RPC version, service address and port, netid]

instead of

  [RPC program, RPC version, port, protocol]

Service address is typically ANYADDR, but can be a specific address
of one of the interfaces on a multi-homed host.  The third item in
the new tuple is expressed as a universal address.

The current Linux rpcbind implementation registers a netid for both
protocol families when RPCB_SET is done for just the PF_INET6 version
of the netid (ie udp6 or tcp6).  So registering "udp6" causes a
registration for "udp" to appear automatically as well.

We've recently determined that this is incorrect behavior.  In the
TI-RPC world, "udp6" is not meant to imply that the registered RPC
service handles requests from AF_INET as well, even if the listener
socket does address mapping.  "udp" and "udp6" are entirely separate
capabilities, and must be registered separately.

The Linux kernel, unlike TI-RPC, leverages address mapping to allow a
single listener socket to handle requests for both AF_INET and AF_INET6.
This is still OK, but the kernel currently assumes registering "udp6"
will cover "udp" as well.  It registers only "udp6" for it's AF_INET6
services, even though they handle both AF_INET and AF_INET6 on the same
port.

So svc_register() actually needs to register both "udp" and "udp6"
explicitly (and likewise for TCP).  Until rpcbind is fixed, the
kernel can ignore the return code for the second RPCB_SET call.

Please merge this with commit 15231312:

    SUNRPC: Support IPv6 when registering kernel RPC services

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Cc: Olaf Kirch <okir@suse.de>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent e018040a

net/sunrpc/svc.c

+100 −43
Original line number Diff line number Diff line
@@ -720,33 +720,18 @@ svc_exit_thread(struct svc_rqst *rqstp) 
EXPORT_SYMBOL(svc_exit_thread);



#ifdef CONFIG_SUNRPC_REGISTER_V4



/*

 * Registering kernel RPC services with rpcbind version 2 will work

 * over either IPv4 or IPv6, since the Linux kernel always registers

 * services for the "any" address.

 *

 * However, the local rpcbind daemon listens on either only AF_INET

 * or AF_INET6 (never both).  When it listens on AF_INET6, an rpcbind

 * version 2 registration will result in registering the service at

 * IN6ADDR_ANY, even if the RPC service being registered is not

 * IPv6-enabled.

 *

 * Rpcbind version 4 allows us to be a little more specific.  Kernel

 * RPC services that don't yet support AF_INET6 can register

 * themselves as IPv4-only with the local rpcbind daemon, even if the

 * daemon is listening only on AF_INET6.

 * Register an "inet" protocol family netid with the local

 * rpcbind daemon via an rpcbind v4 SET request.

 *

 * And, registering IPv6-enabled kernel RPC services via AF_INET6

 * verifies that the local user space rpcbind daemon is properly

 * configured to support remote AF_INET6 rpcbind requests.

 * No netconfig infrastructure is available in the kernel, so

 * we map IP_ protocol numbers to netids by hand.

 *

 * An AF_INET6 registration request will fail if the local rpcbind

 * daemon is not set up to listen on AF_INET6.  Likewise, we fail

 * AF_INET6 registration requests if svc_register() is configured to

 * support only rpcbind version 2.

 * Returns zero on success; a negative errno value is returned

 * if any error occurs.

 */

static int __svc_register(const u32 program, const u32 version,

			  const sa_family_t family,

static int __svc_rpcb_register4(const u32 program, const u32 version,

				const unsigned short protocol,

				const unsigned short port)

{
@@ -755,34 +740,105 @@ static int __svc_register(const u32 program, const u32 version, 
		.sin_addr.s_addr	= htonl(INADDR_ANY),

		.sin_port		= htons(port),

	};

	char *netid;



	switch (protocol) {

	case IPPROTO_UDP:

		netid = RPCBIND_NETID_UDP;

		break;

	case IPPROTO_TCP:

		netid = RPCBIND_NETID_TCP;

		break;

	default:

		return -EPROTONOSUPPORT;

	}



	return rpcb_v4_register(program, version,

				(struct sockaddr *)&sin, netid);

}



/*

 * Register an "inet6" protocol family netid with the local

 * rpcbind daemon via an rpcbind v4 SET request.

 *

 * No netconfig infrastructure is available in the kernel, so

 * we map IP_ protocol numbers to netids by hand.

 *

 * Returns zero on success; a negative errno value is returned

 * if any error occurs.

 */

static int __svc_rpcb_register6(const u32 program, const u32 version,

				const unsigned short protocol,

				const unsigned short port)

{

	struct sockaddr_in6 sin6 = {

		.sin6_family		= AF_INET6,

		.sin6_addr		= IN6ADDR_ANY_INIT,

		.sin6_port		= htons(port),

	};

	struct sockaddr *sap;

	char *netid;



	switch (family) {

	case AF_INET:

		sap = (struct sockaddr *)&sin;

		netid = RPCBIND_NETID_TCP;

		if (protocol == IPPROTO_UDP)

			netid = RPCBIND_NETID_UDP;

	switch (protocol) {

	case IPPROTO_UDP:

		netid = RPCBIND_NETID_UDP6;

		break;

	case AF_INET6:

		sap = (struct sockaddr *)&sin6;

	case IPPROTO_TCP:

		netid = RPCBIND_NETID_TCP6;

		if (protocol == IPPROTO_UDP)

			netid = RPCBIND_NETID_UDP6;

		break;

	default:

		return -EAFNOSUPPORT;

		return -EPROTONOSUPPORT;

	}



	return rpcb_v4_register(program, version,

				(struct sockaddr *)&sin6, netid);

}



	return rpcb_v4_register(program, version, sap, netid);

/*

 * Register a kernel RPC service via rpcbind version 4.

 *

 * Returns zero on success; a negative errno value is returned

 * if any error occurs.

 */

static int __svc_register(const u32 program, const u32 version,

			  const sa_family_t family,

			  const unsigned short protocol,

			  const unsigned short port)

{

	int error;



	switch (family) {

	case AF_INET:

		return __svc_rpcb_register4(program, version,

						protocol, port);

	case AF_INET6:

		error = __svc_rpcb_register6(program, version,

						protocol, port);

		if (error < 0)

			return error;



		/*

		 * Work around bug in some versions of Linux rpcbind

		 * which don't allow registration of both inet and

		 * inet6 netids.

		 *

		 * Error return ignored for now.

		 */

		__svc_rpcb_register4(program, version,

						protocol, port);

		return 0;

	}



	return -EAFNOSUPPORT;

}

#else



#else	/* CONFIG_SUNRPC_REGISTER_V4 */



/*

 * Register a kernel RPC service via rpcbind version 2.

 *

 * Returns zero on success; a negative errno value is returned

 * if any error occurs.

 */

static int __svc_register(const u32 program, const u32 version,

			  sa_family_t family,

			  const unsigned short protocol,
@@ -793,7 +849,8 @@ static int __svc_register(const u32 program, const u32 version, 


	return rpcb_register(program, version, protocol, port);

}

#endif



#endif /* CONFIG_SUNRPC_REGISTER_V4 */



/**

 * svc_register - register an RPC service with the local portmapper
@@ -817,12 +874,12 @@ int svc_register(const struct svc_serv *serv, const unsigned short proto, 
			if (progp->pg_vers[i] == NULL)

				continue;



			dprintk("svc: svc_register(%s, %u, %s, %u, %d)%s\n",

			dprintk("svc: svc_register(%sv%d, %s, %u, %u)%s\n",

					progp->pg_name,

					serv->sv_family,

					i,

					proto == IPPROTO_UDP?  "udp" : "tcp",

					port,

					i,

					serv->sv_family,

					progp->pg_vers[i]->vs_hidden?

						" (but not telling portmap)" : "");