SUNRPC: Support IPv6 when registering kernel RPC services

In order to advertise NFS-related services on IPv6 interfaces via
rpcbind, the kernel RPC server implementation must use
rpcb_v4_register() instead of rpcb_register().

A new kernel build option allows distributions to use the legacy
v2 call until they integrate an appropriate user-space rpcbind
daemon that can support IPv6 RPC services.

I tried adding some automatic logic to fall back if registering
with a v4 protocol request failed, but there are too many corner
cases.  So I just made it a compile-time switch that distributions
can throw when they've replaced portmapper with rpcbind.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Chuck Lever 2008-08-18 19:34:16 -04:00 committed by J. Bruce Fields
parent 7252d575ab
commit a26cfad6e0
3 changed files with 113 additions and 8 deletions

View File

@ -1773,6 +1773,28 @@ config SUNRPC_XPRT_RDMA
If unsure, say N.
config SUNRPC_REGISTER_V4
bool "Register local RPC services via rpcbind v4 (EXPERIMENTAL)"
depends on SUNRPC && EXPERIMENTAL
default n
help
Sun added support for registering RPC services at an IPv6
address by creating two new versions of the rpcbind protocol
(RFC 1833).
This option enables support in the kernel RPC server for
registering kernel RPC services via version 4 of the rpcbind
protocol. If you enable this option, you must run a portmapper
daemon that supports rpcbind protocol version 4.
Serving NFS over IPv6 from knfsd (the kernel's NFS server)
requires that you enable this option and use a portmapper that
supports rpcbind version 4.
If unsure, say N to get traditional behavior (register kernel
RPC services using only rpcbind version 2). Distributions
using the legacy Linux portmapper daemon must say N here.
config RPCSEC_GSS_KRB5
tristate "Secure RPC: Kerberos V mechanism (EXPERIMENTAL)"
depends on SUNRPC && EXPERIMENTAL

View File

@ -393,7 +393,9 @@ struct svc_serv * svc_create_pooled(struct svc_program *, unsigned int,
int svc_set_num_threads(struct svc_serv *, struct svc_pool *, int);
void svc_destroy(struct svc_serv *);
int svc_process(struct svc_rqst *);
int svc_register(struct svc_serv *, int, unsigned short);
int svc_register(const struct svc_serv *, const unsigned short,
const unsigned short);
void svc_wake_up(struct svc_serv *);
void svc_reserve(struct svc_rqst *rqstp, int space);
struct svc_pool * svc_pool_for_cpu(struct svc_serv *serv, int cpu);

View File

@ -719,13 +719,92 @@ svc_exit_thread(struct svc_rqst *rqstp)
}
EXPORT_SYMBOL(svc_exit_thread);
#ifdef CONFIG_SUNRPC_REGISTER_V4
/*
* Register an RPC service with the local portmapper.
* To unregister a service, call this routine with
* proto and port == 0.
* 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.
*
* 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.
*
* 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.
*/
int
svc_register(struct svc_serv *serv, int proto, unsigned short port)
static int __svc_register(const u32 program, const u32 version,
const sa_family_t family,
const unsigned short protocol,
const unsigned short port)
{
struct sockaddr_in sin = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl(INADDR_ANY),
.sin_port = htons(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;
break;
case AF_INET6:
sap = (struct sockaddr *)&sin6;
netid = RPCBIND_NETID_TCP6;
if (protocol == IPPROTO_UDP)
netid = RPCBIND_NETID_UDP6;
break;
default:
return -EAFNOSUPPORT;
}
return rpcb_v4_register(program, version, sap, netid);
}
#else
static int __svc_register(const u32 program, const u32 version,
sa_family_t family,
const unsigned short protocol,
const unsigned short port)
{
if (family != AF_INET)
return -EAFNOSUPPORT;
return rpcb_register(program, version, protocol, port);
}
#endif
/**
* svc_register - register an RPC service with the local portmapper
* @serv: svc_serv struct for the service to register
* @proto: transport protocol number to advertise
* @port: port to advertise
*
* Service is registered for any address in serv's address family
*/
int svc_register(const struct svc_serv *serv, const unsigned short proto,
const unsigned short port)
{
struct svc_program *progp;
unsigned int i;
@ -738,8 +817,9 @@ svc_register(struct svc_serv *serv, int proto, unsigned short port)
if (progp->pg_vers[i] == NULL)
continue;
dprintk("svc: svc_register(%s, %s, %d, %d)%s\n",
dprintk("svc: svc_register(%s, %u, %s, %u, %d)%s\n",
progp->pg_name,
serv->sv_family,
proto == IPPROTO_UDP? "udp" : "tcp",
port,
i,
@ -749,7 +829,8 @@ svc_register(struct svc_serv *serv, int proto, unsigned short port)
if (progp->pg_vers[i]->vs_hidden)
continue;
error = rpcb_register(progp->pg_prog, i, proto, port);
error = __svc_register(progp->pg_prog, i,
serv->sv_family, proto, port);
if (error < 0)
break;
}