On Fri, Jul 18, 2008 at 7:40 PM, J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
> On Mon, Jun 30, 2008 at 06:46:01PM -0400, Chuck Lever wrote:
>> 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().
>>
>> Legacy support (register using portmapper/rpcbindv2) is still available.
>> The new rpcbind version is not used unless enabled via a CONFIG option.
>
> So a kernel built with CONFIG_SUNRPC_REGISTER_V4 will no longer support
> old userspace?
Precisely speaking it will require that user space is running rpcbind
(or some other rpcbind-like daemon that support version 4 of the
rpcbind protocol) instead of the legacy portmapper.
>>
>> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
>> ---
>>
>> net/sunrpc/svc.c | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 files changed, 73 insertions(+), 0 deletions(-)
>>
>>
>> diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
>> index c31a1e4..13cca03 100644
>> --- a/net/sunrpc/svc.c
>> +++ b/net/sunrpc/svc.c
>> @@ -749,6 +749,74 @@ 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.
>> + *
>> + * 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.
>> + */
>> +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;
>> + int error, result;
>> +
>> + 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;
>> + }
>> +
>> + error = rpcb_v4_register(program, version, sap, netid, &result);
>> + if (!result)
>> + error = -EACCES;
>> + return error;
>> +}
>> +#else
>> static int __svc_register(const u32 program, const u32 version,
>> sa_family_t family,
>> const unsigned short protocol,
>> @@ -756,11 +824,15 @@ static int __svc_register(const u32 program, const u32 version,
>> {
>> int error, result;
>>
>> + if (family != AF_INET)
>> + return -EAFNOSUPPORT;
>> +
>> error = rpcb_register(program, version, protocol, port, &result);
>> if (!result)
>> error = -EACCES;
>> return error;
>> }
>> +#endif
>>
>> /**
>> * svc_register - register an RPC service with the local portmapper
>> @@ -768,6 +840,7 @@ static int __svc_register(const u32 program, const u32 version,
>> * @protocol: 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 protocol,
>> const unsigned short port)
>>
--
Chuck Lever
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