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authorDavid Howells <dhowells@redhat.com>2017-06-05 14:30:49 +0100
committerDavid Howells <dhowells@redhat.com>2017-06-05 14:30:49 +0100
commit4722974d90e06d0164ca1b73a6b34cec6bdb64ad (patch)
treef8f839ed9e2b63691c8122c6e94dc0d4fea9d98f /net/rxrpc/ar-internal.h
parent28036f44851e2515aa91b547b45cefddcac52ff6 (diff)
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rxrpc: Implement service upgrade
Implement AuriStor's service upgrade facility. There are three problems that this is meant to deal with: (1) Various of the standard AFS RPC calls have IPv4 addresses in their requests and/or replies - but there's no room for including IPv6 addresses. (2) Definition of IPv6-specific RPC operations in the standard operation sets has not yet been achieved. (3) One could envision the creation a new service on the same port that as the original service. The new service could implement improved operations - and the client could try this first, falling back to the original service if it's not there. Unfortunately, certain servers ignore packets addressed to a service they don't implement and don't respond in any way - not even with an ABORT. This means that the client must then wait for the call timeout to occur. What service upgrade does is to see if the connection is marked as being 'upgradeable' and if so, change the service ID in the server and thus the request and reply formats. Note that the upgrade isn't mandatory - a server that supports only the original call set will ignore the upgrade request. In the protocol, the procedure is then as follows: (1) To request an upgrade, the first DATA packet in a new connection must have the userStatus set to 1 (this is normally 0). The userStatus value is normally ignored by the server. (2) If the server doesn't support upgrading, the reply packets will contain the same service ID as for the first request packet. (3) If the server does support upgrading, all future reply packets on that connection will contain the new service ID and the new service ID will be applied to *all* further calls on that connection as well. (4) The RPC op used to probe the upgrade must take the same request data as the shadow call in the upgrade set (but may return a different reply). GetCapability RPC ops were added to all standard sets for just this purpose. Ops where the request formats differ cannot be used for probing. (5) The client must wait for completion of the probe before sending any further RPC ops to the same destination. It should then use the service ID that recvmsg() reported back in all future calls. (6) The shadow service must have call definitions for all the operation IDs defined by the original service. To support service upgrading, a server should: (1) Call bind() twice on its AF_RXRPC socket before calling listen(). Each bind() should supply a different service ID, but the transport addresses must be the same. This allows the server to receive requests with either service ID. (2) Enable automatic upgrading by calling setsockopt(), specifying RXRPC_UPGRADEABLE_SERVICE and passing in a two-member array of unsigned shorts as the argument: unsigned short optval[2]; This specifies a pair of service IDs. They must be different and must match the service IDs bound to the socket. Member 0 is the service ID to upgrade from and member 1 is the service ID to upgrade to. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'net/rxrpc/ar-internal.h')
-rw-r--r--net/rxrpc/ar-internal.h10
1 files changed, 8 insertions, 2 deletions
diff --git a/net/rxrpc/ar-internal.h b/net/rxrpc/ar-internal.h
index 781fbc253b5a..c1ebd886a53f 100644
--- a/net/rxrpc/ar-internal.h
+++ b/net/rxrpc/ar-internal.h
@@ -144,8 +144,13 @@ struct rxrpc_sock {
#define RXRPC_SECURITY_MAX RXRPC_SECURITY_ENCRYPT
bool exclusive; /* Exclusive connection for a client socket */
u16 second_service; /* Additional service bound to the endpoint */
+ struct {
+ /* Service upgrade information */
+ u16 from; /* Service ID to upgrade (if not 0) */
+ u16 to; /* service ID to upgrade to */
+ } service_upgrade;
sa_family_t family; /* Protocol family created with */
- struct sockaddr_rxrpc srx; /* local address */
+ struct sockaddr_rxrpc srx; /* Primary Service/local addresses */
struct sockaddr_rxrpc connect_srx; /* Default client address from connect() */
};
@@ -861,7 +866,8 @@ static inline void rxrpc_put_connection(struct rxrpc_connection *conn)
struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
struct sk_buff *);
struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *, gfp_t);
-void rxrpc_new_incoming_connection(struct rxrpc_connection *, struct sk_buff *);
+void rxrpc_new_incoming_connection(struct rxrpc_sock *,
+ struct rxrpc_connection *, struct sk_buff *);
void rxrpc_unpublish_service_conn(struct rxrpc_connection *);
/*