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SUNRPC: Register both netids for AF_INET6 servers

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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: Chuck Lever <chuck.lever@oracle.com>
Cc: Olaf Kirch <okir@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Chuck Lever 2008-09-15 16:27:23 -05:00 committed by J. Bruce Fields
parent e018040a82
commit 2c7eb0b206
1 changed files with 101 additions and 44 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

145
net/sunrpc/svc.c
View file

@ -720,69 +720,125 @@ 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.
* Register an "inet" protocol family netid with the local
* rpcbind daemon via an rpcbind v4 SET request.
*
* 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.
* No netconfig infrastructure is available in the kernel, so
* we map IP_ protocol numbers to netids by hand.
*
* 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.
* 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)
static int __svc_rpcb_register4(const u32 program, const u32 version,
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),
};
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 (protocol) {
case IPPROTO_UDP:
netid = RPCBIND_NETID_UDP6;
break;
case IPPROTO_TCP:
netid = RPCBIND_NETID_TCP6;
break;
default:
return -EPROTONOSUPPORT;
}
return rpcb_v4_register(program, version,
(struct sockaddr *)&sin6, 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:
sap = (struct sockaddr *)&sin;
netid = RPCBIND_NETID_TCP;
if (protocol == IPPROTO_UDP)
netid = RPCBIND_NETID_UDP;
break;
return __svc_rpcb_register4(program, version,
protocol, port);
case AF_INET6:
sap = (struct sockaddr *)&sin6;
netid = RPCBIND_NETID_TCP6;
if (protocol == IPPROTO_UDP)
netid = RPCBIND_NETID_UDP6;
break;
default:
return -EAFNOSUPPORT;
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 rpcb_v4_register(program, version, sap, netid);
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)" : "");