X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fl2tp%2Fl2tp_core.c;h=3954b18f42ee98d5c69a2e13c647e6fe56e1900e;hb=584063be6f269a5ed9f46538b57480822bddfe22;hp=89ff8c67943e8af26efe1bac80b306e297921ebd;hpb=22c6b32d8d9b7adf903c19b7e108062431fdc6fc;p=pandora-kernel.git diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 89ff8c67943e..3954b18f42ee 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -225,7 +225,58 @@ struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunn } EXPORT_SYMBOL_GPL(l2tp_session_find); -struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) +/* Like l2tp_session_find() but takes a reference on the returned session. + * Optionally calls session->ref() too if do_ref is true. + */ +struct l2tp_session *l2tp_session_get(struct net *net, + struct l2tp_tunnel *tunnel, + u32 session_id, bool do_ref) +{ + struct hlist_head *session_list; + struct l2tp_session *session; + struct hlist_node *walk; + + if (!tunnel) { + struct l2tp_net *pn = l2tp_pernet(net); + + session_list = l2tp_session_id_hash_2(pn, session_id); + + rcu_read_lock_bh(); + hlist_for_each_entry_rcu(session, walk, session_list, global_hlist) { + if (session->session_id == session_id) { + l2tp_session_inc_refcount(session); + if (do_ref && session->ref) + session->ref(session); + rcu_read_unlock_bh(); + + return session; + } + } + rcu_read_unlock_bh(); + + return NULL; + } + + session_list = l2tp_session_id_hash(tunnel, session_id); + read_lock_bh(&tunnel->hlist_lock); + hlist_for_each_entry(session, walk, session_list, hlist) { + if (session->session_id == session_id) { + l2tp_session_inc_refcount(session); + if (do_ref && session->ref) + session->ref(session); + read_unlock_bh(&tunnel->hlist_lock); + + return session; + } + } + read_unlock_bh(&tunnel->hlist_lock); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_session_get); + +struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth, + bool do_ref) { int hash; struct hlist_node *walk; @@ -236,6 +287,9 @@ struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { hlist_for_each_entry(session, walk, &tunnel->session_hlist[hash], hlist) { if (++count > nth) { + l2tp_session_inc_refcount(session); + if (do_ref && session->ref) + session->ref(session); read_unlock_bh(&tunnel->hlist_lock); return session; } @@ -246,12 +300,13 @@ struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth) return NULL; } -EXPORT_SYMBOL_GPL(l2tp_session_find_nth); +EXPORT_SYMBOL_GPL(l2tp_session_get_nth); /* Lookup a session by interface name. * This is very inefficient but is only used by management interfaces. */ -struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) +struct l2tp_session *l2tp_session_get_by_ifname(struct net *net, char *ifname, + bool do_ref) { struct l2tp_net *pn = l2tp_pernet(net); int hash; @@ -262,7 +317,11 @@ struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) for (hash = 0; hash < L2TP_HASH_SIZE_2; hash++) { hlist_for_each_entry_rcu(session, walk, &pn->l2tp_session_hlist[hash], global_hlist) { if (!strcmp(session->ifname, ifname)) { + l2tp_session_inc_refcount(session); + if (do_ref && session->ref) + session->ref(session); rcu_read_unlock_bh(); + return session; } } @@ -272,7 +331,50 @@ struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname) return NULL; } -EXPORT_SYMBOL_GPL(l2tp_session_find_by_ifname); +EXPORT_SYMBOL_GPL(l2tp_session_get_by_ifname); + +static int l2tp_session_add_to_tunnel(struct l2tp_tunnel *tunnel, + struct l2tp_session *session) +{ + struct l2tp_session *session_walk; + struct hlist_head *g_head; + struct hlist_head *head; + struct l2tp_net *pn; + struct hlist_node *walk; + + head = l2tp_session_id_hash(tunnel, session->session_id); + + write_lock_bh(&tunnel->hlist_lock); + hlist_for_each_entry(session_walk, walk, head, hlist) + if (session_walk->session_id == session->session_id) + goto exist; + + if (tunnel->version == L2TP_HDR_VER_3) { + pn = l2tp_pernet(tunnel->l2tp_net); + g_head = l2tp_session_id_hash_2(l2tp_pernet(tunnel->l2tp_net), + session->session_id); + + spin_lock_bh(&pn->l2tp_session_hlist_lock); + hlist_for_each_entry(session_walk, walk, g_head, global_hlist) + if (session_walk->session_id == session->session_id) + goto exist_glob; + + hlist_add_head_rcu(&session->global_hlist, g_head); + spin_unlock_bh(&pn->l2tp_session_hlist_lock); + } + + hlist_add_head(&session->hlist, head); + write_unlock_bh(&tunnel->hlist_lock); + + return 0; + +exist_glob: + spin_unlock_bh(&pn->l2tp_session_hlist_lock); +exist: + write_unlock_bh(&tunnel->hlist_lock); + + return -EEXIST; +} /* Lookup a tunnel by id */ @@ -524,6 +626,9 @@ static inline int l2tp_verify_udp_checksum(struct sock *sk, * a data (not control) frame before coming here. Fields up to the * session-id have already been parsed and ptr points to the data * after the session-id. + * + * session->ref() must have been called prior to l2tp_recv_common(). + * session->deref() will be called automatically after skb is processed. */ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, @@ -533,14 +638,6 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, int offset; u32 ns, nr; - /* The ref count is increased since we now hold a pointer to - * the session. Take care to decrement the refcnt when exiting - * this function from now on... - */ - l2tp_session_inc_refcount(session); - if (session->ref) - (*session->ref)(session); - /* Parse and check optional cookie */ if (session->peer_cookie_len > 0) { if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { @@ -711,8 +808,6 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, /* Try to dequeue as many skbs from reorder_q as we can. */ l2tp_recv_dequeue(session); - l2tp_session_dec_refcount(session); - return; discard: @@ -721,8 +816,6 @@ discard: if (session->deref) (*session->deref)(session); - - l2tp_session_dec_refcount(session); } EXPORT_SYMBOL(l2tp_recv_common); @@ -818,8 +911,14 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, } /* Find the session context */ - session = l2tp_session_find(tunnel->l2tp_net, tunnel, session_id); + session = l2tp_session_get(tunnel->l2tp_net, tunnel, session_id, true); if (!session || !session->recv_skb) { + if (session) { + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + } + /* Not found? Pass to userspace to deal with */ PRINTK(tunnel->debug, L2TP_MSG_DATA, KERN_INFO, "%s: no session found (%u/%u). Passing up.\n", @@ -828,6 +927,7 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, } l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); + l2tp_session_dec_refcount(session); return 0; @@ -1253,11 +1353,10 @@ static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) /* Remove from tunnel list */ spin_lock_bh(&pn->l2tp_tunnel_list_lock); list_del_rcu(&tunnel->list); + kfree_rcu(tunnel, rcu); spin_unlock_bh(&pn->l2tp_tunnel_list_lock); - synchronize_rcu(); atomic_dec(&l2tp_tunnel_count); - kfree(tunnel); } /* Create a socket for the tunnel, if one isn't set up by @@ -1569,6 +1668,7 @@ static void l2tp_session_set_header_len(struct l2tp_session *session, int versio struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) { struct l2tp_session *session; + int err; session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); if (session != NULL) { @@ -1615,6 +1715,13 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn l2tp_session_set_header_len(session, tunnel->version); + err = l2tp_session_add_to_tunnel(tunnel, session); + if (err) { + kfree(session); + + return ERR_PTR(err); + } + /* Bump the reference count. The session context is deleted * only when this drops to zero. */ @@ -1624,28 +1731,14 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn /* Ensure tunnel socket isn't deleted */ sock_hold(tunnel->sock); - /* Add session to the tunnel's hash list */ - write_lock_bh(&tunnel->hlist_lock); - hlist_add_head(&session->hlist, - l2tp_session_id_hash(tunnel, session_id)); - write_unlock_bh(&tunnel->hlist_lock); - - /* And to the global session list if L2TPv3 */ - if (tunnel->version != L2TP_HDR_VER_2) { - struct l2tp_net *pn = l2tp_pernet(tunnel->l2tp_net); - - spin_lock_bh(&pn->l2tp_session_hlist_lock); - hlist_add_head_rcu(&session->global_hlist, - l2tp_session_id_hash_2(pn, session_id)); - spin_unlock_bh(&pn->l2tp_session_hlist_lock); - } - /* Ignore management session in session count value */ if (session->session_id != 0) atomic_inc(&l2tp_session_count); + + return session; } - return session; + return ERR_PTR(-ENOMEM); } EXPORT_SYMBOL_GPL(l2tp_session_create);