#include <linux/bits.h>
#include <linux/mctp.h>
+#include <linux/netdevice.h>
#include <net/net_namespace.h>
#include <net/sock.h>
mctp_eid_t bind_addr;
__u8 bind_type;
+ /* sendmsg()/recvmsg() uses struct sockaddr_mctp_ext */
+ bool addr_ext;
+
/* list of mctp_sk_key, for incoming tag lookup. updates protected
* by sk->net->keys_lock
*/
struct hlist_head keys;
+
+ /* mechanism for expiring allocated keys; will release an allocated
+ * tag, and any netdev state for a request/response pairing
+ */
+ struct timer_list key_expiry;
};
/* Key for matching incoming packets to sockets or reassembly contexts.
* Packets are matched on (src,dest,tag).
*
- * Lifetime requirements:
+ * Lifetime / locking requirements:
+ *
+ * - individual key data (ie, the struct itself) is protected by key->lock;
+ * changes must be made with that lock held.
+ *
+ * - the lookup fields: peer_addr, local_addr and tag are set before the
+ * key is added to lookup lists, and never updated.
*
- * - keys are free()ed via RCU
+ * - A ref to the key must be held (throuh key->refs) if a pointer to the
+ * key is to be accessed after key->lock is released.
*
* - a mctp_sk_key contains a reference to a struct sock; this is valid
* for the life of the key. On sock destruction (through unhash), the key is
- * removed from lists (see below), and will not be observable after a RCU
- * grace period.
- *
- * any RX occurring within that grace period may still queue to the socket,
- * but will hit the SOCK_DEAD case before the socket is freed.
+ * removed from lists (see below), and marked invalid.
*
* - these mctp_sk_keys appear on two lists:
* 1) the struct mctp_sock->keys list
* 2) the struct netns_mctp->keys list
*
- * updates to either list are performed under the netns_mctp->keys
- * lock.
+ * presences on these lists requires a (single) refcount to be held; both
+ * lists are updated as a single operation.
+ *
+ * Updates and lookups in either list are performed under the
+ * netns_mctp->keys lock. Lookup functions will need to lock the key and
+ * take a reference before unlocking the keys_lock. Consequently, the list's
+ * keys_lock *cannot* be acquired with the individual key->lock held.
*
* - a key may have a sk_buff attached as part of an in-progress message
- * reassembly (->reasm_head). The reassembly context is protected by
- * reasm_lock, which may be acquired with the keys lock (above) held, if
- * necessary. Consequently, keys lock *cannot* be acquired with the
- * reasm_lock held.
+ * reassembly (->reasm_head). The reasm data is protected by the individual
+ * key->lock.
*
* - there are two destruction paths for a mctp_sk_key:
*
* the (complete) reply, or during reassembly errors. Here, we clean up
* the reassembly context (marking reasm_dead, to prevent another from
* starting), and remove the socket from the netns & socket lists.
+ *
+ * - through an expiry timeout, on a per-socket timer
*/
struct mctp_sk_key {
mctp_eid_t peer_addr;
/* per-socket list */
struct hlist_node sklist;
+ /* lock protects against concurrent updates to the reassembly and
+ * expiry data below.
+ */
+ spinlock_t lock;
+
+ /* Keys are referenced during the output path, which may sleep */
+ refcount_t refs;
+
/* incoming fragment reassembly context */
- spinlock_t reasm_lock;
struct sk_buff *reasm_head;
struct sk_buff **reasm_tailp;
bool reasm_dead;
u8 last_seq;
- struct rcu_head rcu;
+ /* key validity */
+ bool valid;
+
+ /* expiry timeout; valid (above) cleared on expiry */
+ unsigned long expiry;
+
+ /* free to use for device flow state tracking. Initialised to
+ * zero on initial key creation
+ */
+ unsigned long dev_flow_state;
+ struct mctp_dev *dev;
};
struct mctp_skb_cb {
unsigned int magic;
unsigned int net;
+ int ifindex; /* extended/direct addressing if set */
mctp_eid_t src;
+ unsigned char halen;
+ unsigned char haddr[MAX_ADDR_LEN];
};
/* skb control-block accessors with a little extra debugging for initial
{
struct mctp_skb_cb *cb = (void *)skb->cb;
+ BUILD_BUG_ON(sizeof(struct mctp_skb_cb) > sizeof(skb->cb));
WARN_ON(cb->magic != 0x4d435450);
return (void *)(skb->cb);
}
+/* If CONFIG_MCTP_FLOWS, we may add one of these as a SKB extension,
+ * indicating the flow to the device driver.
+ */
+struct mctp_flow {
+ struct mctp_sk_key *key;
+};
+
/* Route definition.
*
* These are held in the pernet->mctp.routes list, with RCU protection for
*
* Updates to the route table are performed under rtnl; all reads under RCU,
* so routes cannot be referenced over a RCU grace period. Specifically: A
- * caller cannot block between mctp_route_lookup and passing the route to
- * mctp_do_route.
+ * caller cannot block between mctp_route_lookup and mctp_route_release()
*/
struct mctp_route {
mctp_eid_t min, max;
struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
mctp_eid_t daddr);
-int mctp_do_route(struct mctp_route *rt, struct sk_buff *skb);
-
int mctp_local_output(struct sock *sk, struct mctp_route *rt,
struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag);
+void mctp_key_unref(struct mctp_sk_key *key);
+
/* routing <--> device interface */
unsigned int mctp_default_net(struct net *net);
int mctp_default_net_set(struct net *net, unsigned int index);
projects / linux-2.6-block.git / blobdiff