diff options
Diffstat (limited to 'net/l2tp')
-rw-r--r-- | net/l2tp/l2tp_core.c | 289 | ||||
-rw-r--r-- | net/l2tp/l2tp_core.h | 49 | ||||
-rw-r--r-- | net/l2tp/l2tp_eth.c | 226 | ||||
-rw-r--r-- | net/l2tp/l2tp_ip.c | 114 | ||||
-rw-r--r-- | net/l2tp/l2tp_ip6.c | 137 | ||||
-rw-r--r-- | net/l2tp/l2tp_netlink.c | 124 | ||||
-rw-r--r-- | net/l2tp/l2tp_ppp.c | 403 |
7 files changed, 780 insertions, 562 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 429dbb064240..9a85b0133991 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -112,53 +112,19 @@ struct l2tp_net { spinlock_t l2tp_session_hlist_lock; }; -static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) { return sk->sk_user_data; } -static inline struct l2tp_net *l2tp_pernet(struct net *net) +static inline struct l2tp_net *l2tp_pernet(const struct net *net) { BUG_ON(!net); return net_generic(net, l2tp_net_id); } -/* Tunnel reference counts. Incremented per session that is added to - * the tunnel. - */ -static inline void l2tp_tunnel_inc_refcount_1(struct l2tp_tunnel *tunnel) -{ - atomic_inc(&tunnel->ref_count); -} - -static inline void l2tp_tunnel_dec_refcount_1(struct l2tp_tunnel *tunnel) -{ - if (atomic_dec_and_test(&tunnel->ref_count)) - l2tp_tunnel_free(tunnel); -} -#ifdef L2TP_REFCNT_DEBUG -#define l2tp_tunnel_inc_refcount(_t) \ -do { \ - pr_debug("l2tp_tunnel_inc_refcount: %s:%d %s: cnt=%d\n", \ - __func__, __LINE__, (_t)->name, \ - atomic_read(&_t->ref_count)); \ - l2tp_tunnel_inc_refcount_1(_t); \ -} while (0) -#define l2tp_tunnel_dec_refcount(_t) \ -do { \ - pr_debug("l2tp_tunnel_dec_refcount: %s:%d %s: cnt=%d\n", \ - __func__, __LINE__, (_t)->name, \ - atomic_read(&_t->ref_count)); \ - l2tp_tunnel_dec_refcount_1(_t); \ -} while (0) -#else -#define l2tp_tunnel_inc_refcount(t) l2tp_tunnel_inc_refcount_1(t) -#define l2tp_tunnel_dec_refcount(t) l2tp_tunnel_dec_refcount_1(t) -#endif - /* Session hash global list for L2TPv3. * The session_id SHOULD be random according to RFC3931, but several * L2TP implementations use incrementing session_ids. So we do a real @@ -216,27 +182,6 @@ static void l2tp_tunnel_sock_put(struct sock *sk) sock_put(sk); } -/* Lookup a session by id in the global session list - */ -static struct l2tp_session *l2tp_session_find_2(struct net *net, u32 session_id) -{ - struct l2tp_net *pn = l2tp_pernet(net); - struct hlist_head *session_list = - l2tp_session_id_hash_2(pn, session_id); - struct l2tp_session *session; - - rcu_read_lock_bh(); - hlist_for_each_entry_rcu(session, session_list, global_hlist) { - if (session->session_id == session_id) { - rcu_read_unlock_bh(); - return session; - } - } - rcu_read_unlock_bh(); - - return NULL; -} - /* Session hash list. * The session_id SHOULD be random according to RFC2661, but several * L2TP implementations (Cisco and Microsoft) use incrementing @@ -249,25 +194,67 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; } -/* Lookup a session by id +/* Lookup a tunnel. A new reference is held on the returned tunnel. */ +struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) +{ + const struct l2tp_net *pn = l2tp_pernet(net); + struct l2tp_tunnel *tunnel; + + rcu_read_lock_bh(); + list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { + if (tunnel->tunnel_id == tunnel_id) { + l2tp_tunnel_inc_refcount(tunnel); + rcu_read_unlock_bh(); + + return tunnel; + } + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_get); + +/* Lookup a session. A new reference is held on the returned session. + * Optionally calls session->ref() too if do_ref is true. */ -struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id) +struct l2tp_session *l2tp_session_get(const struct net *net, + struct l2tp_tunnel *tunnel, + u32 session_id, bool do_ref) { struct hlist_head *session_list; struct l2tp_session *session; - /* In L2TPv3, session_ids are unique over all tunnels and we - * sometimes need to look them up before we know the - * tunnel. - */ - if (tunnel == NULL) - return l2tp_session_find_2(net, session_id); + 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, 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, 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; } } @@ -275,7 +262,7 @@ struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunn return NULL; } -EXPORT_SYMBOL_GPL(l2tp_session_find); +EXPORT_SYMBOL_GPL(l2tp_session_get); struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth, bool do_ref) @@ -306,7 +293,9 @@ 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(const struct net *net, + const char *ifname, + bool do_ref) { struct l2tp_net *pn = l2tp_pernet(net); int hash; @@ -316,7 +305,11 @@ 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, &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; } } @@ -326,11 +319,80 @@ 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); + +int l2tp_session_register(struct l2tp_session *session, + struct l2tp_tunnel *tunnel) +{ + struct l2tp_session *session_walk; + struct hlist_head *g_head; + struct hlist_head *head; + struct l2tp_net *pn; + int err; + + head = l2tp_session_id_hash(tunnel, session->session_id); + + write_lock_bh(&tunnel->hlist_lock); + if (!tunnel->acpt_newsess) { + err = -ENODEV; + goto err_tlock; + } + + hlist_for_each_entry(session_walk, head, hlist) + if (session_walk->session_id == session->session_id) { + err = -EEXIST; + goto err_tlock; + } + + 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); + + /* IP encap expects session IDs to be globally unique, while + * UDP encap doesn't. + */ + hlist_for_each_entry(session_walk, g_head, global_hlist) + if (session_walk->session_id == session->session_id && + (session_walk->tunnel->encap == L2TP_ENCAPTYPE_IP || + tunnel->encap == L2TP_ENCAPTYPE_IP)) { + err = -EEXIST; + goto err_tlock_pnlock; + } + + l2tp_tunnel_inc_refcount(tunnel); + sock_hold(tunnel->sock); + hlist_add_head_rcu(&session->global_hlist, g_head); + + spin_unlock_bh(&pn->l2tp_session_hlist_lock); + } else { + l2tp_tunnel_inc_refcount(tunnel); + sock_hold(tunnel->sock); + } + + hlist_add_head(&session->hlist, head); + write_unlock_bh(&tunnel->hlist_lock); + + /* Ignore management session in session count value */ + if (session->session_id != 0) + atomic_inc(&l2tp_session_count); + + return 0; + +err_tlock_pnlock: + spin_unlock_bh(&pn->l2tp_session_hlist_lock); +err_tlock: + write_unlock_bh(&tunnel->hlist_lock); + + return err; +} +EXPORT_SYMBOL_GPL(l2tp_session_register); /* Lookup a tunnel by id */ -struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) +struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id) { struct l2tp_tunnel *tunnel; struct l2tp_net *pn = l2tp_pernet(net); @@ -348,7 +410,7 @@ struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id) } EXPORT_SYMBOL_GPL(l2tp_tunnel_find); -struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth) +struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth) { struct l2tp_net *pn = l2tp_pernet(net); struct l2tp_tunnel *tunnel; @@ -636,6 +698,9 @@ discard: * 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, @@ -645,14 +710,6 @@ 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)) { @@ -803,8 +860,6 @@ 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: @@ -813,8 +868,6 @@ discard: if (session->deref) (*session->deref)(session); - - l2tp_session_dec_refcount(session); } EXPORT_SYMBOL(l2tp_recv_common); @@ -921,8 +974,14 @@ 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 */ l2tp_info(tunnel, L2TP_MSG_DATA, "%s: no session found (%u/%u). Passing up.\n", @@ -931,10 +990,13 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, } if (tunnel->version == L2TP_HDR_VER_3 && - l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) + l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) { + l2tp_session_dec_refcount(session); goto error; + } l2tp_recv_common(session, skb, ptr, optr, hdrflags, length, payload_hook); + l2tp_session_dec_refcount(session); return 0; @@ -1079,6 +1141,7 @@ static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, /* Queue the packet to IP for output */ skb->ignore_df = 1; + skb_dst_drop(skb); #if IS_ENABLED(CONFIG_IPV6) if (tunnel->sock->sk_family == PF_INET6 && !tunnel->v4mapped) error = inet6_csk_xmit(tunnel->sock, skb, NULL); @@ -1143,10 +1206,6 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len goto out_unlock; } - /* Get routing info from the tunnel socket */ - skb_dst_drop(skb); - skb_dst_set(skb, sk_dst_check(sk, 0)); - inet = inet_sk(sk); fl = &inet->cork.fl; switch (tunnel->encap) { @@ -1218,7 +1277,6 @@ static void l2tp_tunnel_destruct(struct sock *sk) /* Remove hooks into tunnel socket */ sk->sk_destruct = tunnel->old_sk_destruct; sk->sk_user_data = NULL; - tunnel->sock = NULL; /* Remove the tunnel struct from the tunnel list */ pn = l2tp_pernet(tunnel->l2tp_net); @@ -1228,6 +1286,8 @@ static void l2tp_tunnel_destruct(struct sock *sk) atomic_dec(&l2tp_tunnel_count); l2tp_tunnel_closeall(tunnel); + + tunnel->sock = NULL; l2tp_tunnel_dec_refcount(tunnel); /* Call the original destructor */ @@ -1252,6 +1312,7 @@ void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) tunnel->name); write_lock_bh(&tunnel->hlist_lock); + tunnel->acpt_newsess = false; for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { again: hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { @@ -1262,6 +1323,9 @@ again: hlist_del_init(&session->hlist); + if (test_and_set_bit(0, &session->dead)) + goto again; + if (session->ref != NULL) (*session->ref)(session); @@ -1302,17 +1366,6 @@ static void l2tp_udp_encap_destroy(struct sock *sk) } } -/* Really kill the tunnel. - * Come here only when all sessions have been cleared from the tunnel. - */ -static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) -{ - BUG_ON(atomic_read(&tunnel->ref_count) != 0); - BUG_ON(tunnel->sock != NULL); - l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: free...\n", tunnel->name); - kfree_rcu(tunnel, rcu); -} - /* Workqueue tunnel deletion function */ static void l2tp_tunnel_del_work(struct work_struct *work) { @@ -1524,6 +1577,8 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 tunnel_id, fd); goto err; } + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + goto err; switch (encap) { case L2TP_ENCAPTYPE_UDP: if (sk->sk_protocol != IPPROTO_UDP) { @@ -1563,6 +1618,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 tunnel->magic = L2TP_TUNNEL_MAGIC; sprintf(&tunnel->name[0], "tunl %u", tunnel_id); rwlock_init(&tunnel->hlist_lock); + tunnel->acpt_newsess = true; /* The net we belong to */ tunnel->l2tp_net = net; @@ -1710,6 +1766,9 @@ EXPORT_SYMBOL_GPL(__l2tp_session_unhash); */ int l2tp_session_delete(struct l2tp_session *session) { + if (test_and_set_bit(0, &session->dead)) + return 0; + if (session->ref) (*session->ref)(session); __l2tp_session_unhash(session); @@ -1800,37 +1859,12 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn l2tp_session_set_header_len(session, tunnel->version); - /* Bump the reference count. The session context is deleted - * only when this drops to zero. - */ l2tp_session_inc_refcount(session); - l2tp_tunnel_inc_refcount(tunnel); - - /* 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); @@ -1864,6 +1898,9 @@ static __net_exit void l2tp_exit_net(struct net *net) l2tp_tunnel_delete(tunnel); } rcu_read_unlock_bh(); + + flush_workqueue(l2tp_wq); + rcu_barrier(); } static struct pernet_operations l2tp_net_ops = { diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index fad47e9d74bc..57da0f1d62dd 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -23,16 +23,6 @@ #define L2TP_HASH_BITS_2 8 #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) -/* Debug message categories for the DEBUG socket option */ -enum { - L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if - * compiled in) */ - L2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel - * interface */ - L2TP_MSG_SEQ = (1 << 2), /* sequence numbers */ - L2TP_MSG_DATA = (1 << 3), /* data packets */ -}; - struct sk_buff; struct l2tp_stats { @@ -85,6 +75,7 @@ struct l2tp_session_cfg { struct l2tp_session { int magic; /* should be * L2TP_SESSION_MAGIC */ + long dead; struct l2tp_tunnel *tunnel; /* back pointer to tunnel * context */ @@ -174,6 +165,10 @@ struct l2tp_tunnel { struct rcu_head rcu; rwlock_t hlist_lock; /* protect session_hlist */ + bool acpt_newsess; /* Indicates whether this + * tunnel accepts new sessions. + * Protected by hlist_lock. + */ struct hlist_head session_hlist[L2TP_HASH_SIZE]; /* hashed list of sessions, * hashed by id */ @@ -209,7 +204,9 @@ struct l2tp_tunnel { }; struct l2tp_nl_cmd_ops { - int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg); + int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg); int (*session_delete)(struct l2tp_session *session); }; @@ -243,14 +240,18 @@ out: return tunnel; } -struct l2tp_session *l2tp_session_find(struct net *net, - struct l2tp_tunnel *tunnel, - u32 session_id); +struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); + +struct l2tp_session *l2tp_session_get(const struct net *net, + struct l2tp_tunnel *tunnel, + u32 session_id, bool do_ref); struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth, bool do_ref); -struct l2tp_session *l2tp_session_find_by_ifname(struct net *net, char *ifname); -struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id); -struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth); +struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, + const char *ifname, + bool do_ref); +struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id); +struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth); int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, @@ -261,6 +262,9 @@ 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); +int l2tp_session_register(struct l2tp_session *session, + struct l2tp_tunnel *tunnel); + void __l2tp_session_unhash(struct l2tp_session *session); int l2tp_session_delete(struct l2tp_session *session); void l2tp_session_free(struct l2tp_session *session); @@ -279,6 +283,17 @@ int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); +static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) +{ + atomic_inc(&tunnel->ref_count); +} + +static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) +{ + if (atomic_dec_and_test(&tunnel->ref_count)) + kfree_rcu(tunnel, rcu); +} + /* Session reference counts. Incremented when code obtains a reference * to a session. */ diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c index e253c26f31ac..e0a65ee1e830 100644 --- a/net/l2tp/l2tp_eth.c +++ b/net/l2tp/l2tp_eth.c @@ -30,6 +30,9 @@ #include <net/xfrm.h> #include <net/net_namespace.h> #include <net/netns/generic.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/udp.h> #include "l2tp_core.h" @@ -41,7 +44,6 @@ struct l2tp_eth { struct net_device *dev; struct sock *tunnel_sock; struct l2tp_session *session; - struct list_head list; atomic_long_t tx_bytes; atomic_long_t tx_packets; atomic_long_t tx_dropped; @@ -52,20 +54,9 @@ struct l2tp_eth { /* via l2tp_session_priv() */ struct l2tp_eth_sess { - struct net_device *dev; -}; - -/* per-net private data for this module */ -static unsigned int l2tp_eth_net_id; -struct l2tp_eth_net { - struct list_head l2tp_eth_dev_list; - spinlock_t l2tp_eth_lock; + struct net_device __rcu *dev; }; -static inline struct l2tp_eth_net *l2tp_eth_pernet(struct net *net) -{ - return net_generic(net, l2tp_eth_net_id); -} static struct lock_class_key l2tp_eth_tx_busylock; static int l2tp_eth_dev_init(struct net_device *dev) @@ -82,12 +73,13 @@ static int l2tp_eth_dev_init(struct net_device *dev) static void l2tp_eth_dev_uninit(struct net_device *dev) { struct l2tp_eth *priv = netdev_priv(dev); - struct l2tp_eth_net *pn = l2tp_eth_pernet(dev_net(dev)); + struct l2tp_eth_sess *spriv; - spin_lock(&pn->l2tp_eth_lock); - list_del_init(&priv->list); - spin_unlock(&pn->l2tp_eth_lock); - dev_put(dev); + spriv = l2tp_session_priv(priv->session); + RCU_INIT_POINTER(spriv->dev, NULL); + /* No need for synchronize_net() here. We're called by + * unregister_netdev*(), which does the synchronisation for us. + */ } static int l2tp_eth_dev_xmit(struct sk_buff *skb, struct net_device *dev) @@ -141,8 +133,8 @@ static void l2tp_eth_dev_setup(struct net_device *dev) static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) { struct l2tp_eth_sess *spriv = l2tp_session_priv(session); - struct net_device *dev = spriv->dev; - struct l2tp_eth *priv = netdev_priv(dev); + struct net_device *dev; + struct l2tp_eth *priv; if (session->debug & L2TP_MSG_DATA) { unsigned int length; @@ -166,16 +158,25 @@ static void l2tp_eth_dev_recv(struct l2tp_session *session, struct sk_buff *skb, skb_dst_drop(skb); nf_reset(skb); + rcu_read_lock(); + dev = rcu_dereference(spriv->dev); + if (!dev) + goto error_rcu; + + priv = netdev_priv(dev); if (dev_forward_skb(dev, skb) == NET_RX_SUCCESS) { atomic_long_inc(&priv->rx_packets); atomic_long_add(data_len, &priv->rx_bytes); } else { atomic_long_inc(&priv->rx_errors); } + rcu_read_unlock(); + return; +error_rcu: + rcu_read_unlock(); error: - atomic_long_inc(&priv->rx_errors); kfree_skb(skb); } @@ -186,11 +187,15 @@ static void l2tp_eth_delete(struct l2tp_session *session) if (session) { spriv = l2tp_session_priv(session); - dev = spriv->dev; + + rtnl_lock(); + dev = rtnl_dereference(spriv->dev); if (dev) { - unregister_netdev(dev); - spriv->dev = NULL; + unregister_netdevice(dev); + rtnl_unlock(); module_put(THIS_MODULE); + } else { + rtnl_unlock(); } } } @@ -200,41 +205,89 @@ static void l2tp_eth_show(struct seq_file *m, void *arg) { struct l2tp_session *session = arg; struct l2tp_eth_sess *spriv = l2tp_session_priv(session); - struct net_device *dev = spriv->dev; + struct net_device *dev; + + rcu_read_lock(); + dev = rcu_dereference(spriv->dev); + if (!dev) { + rcu_read_unlock(); + return; + } + dev_hold(dev); + rcu_read_unlock(); seq_printf(m, " interface %s\n", dev->name); + + dev_put(dev); } #endif -static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) +static void l2tp_eth_adjust_mtu(struct l2tp_tunnel *tunnel, + struct l2tp_session *session, + struct net_device *dev) +{ + unsigned int overhead = 0; + struct dst_entry *dst; + u32 l3_overhead = 0; + + /* if the encap is UDP, account for UDP header size */ + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + overhead += sizeof(struct udphdr); + dev->needed_headroom += sizeof(struct udphdr); + } + if (session->mtu != 0) { + dev->mtu = session->mtu; + dev->needed_headroom += session->hdr_len; + return; + } + lock_sock(tunnel->sock); + l3_overhead = kernel_sock_ip_overhead(tunnel->sock); + release_sock(tunnel->sock); + if (l3_overhead == 0) { + /* L3 Overhead couldn't be identified, this could be + * because tunnel->sock was NULL or the socket's + * address family was not IPv4 or IPv6, + * dev mtu stays at 1500. + */ + return; + } + /* Adjust MTU, factor overhead - underlay L3, overlay L2 hdr + * UDP overhead, if any, was already factored in above. + */ + overhead += session->hdr_len + ETH_HLEN + l3_overhead; + + /* If PMTU discovery was enabled, use discovered MTU on L2TP device */ + dst = sk_dst_get(tunnel->sock); + if (dst) { + /* dst_mtu will use PMTU if found, else fallback to intf MTU */ + u32 pmtu = dst_mtu(dst); + + if (pmtu != 0) + dev->mtu = pmtu; + dst_release(dst); + } + session->mtu = dev->mtu - overhead; + dev->mtu = session->mtu; + dev->needed_headroom += session->hdr_len; +} + +static int l2tp_eth_create(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg) { struct net_device *dev; char name[IFNAMSIZ]; - struct l2tp_tunnel *tunnel; struct l2tp_session *session; struct l2tp_eth *priv; struct l2tp_eth_sess *spriv; int rc; - struct l2tp_eth_net *pn; - - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (!tunnel) { - rc = -ENODEV; - goto out; - } - - session = l2tp_session_find(net, tunnel, session_id); - if (session) { - rc = -EEXIST; - goto out; - } if (cfg->ifname) { dev = dev_get_by_name(net, cfg->ifname); if (dev) { dev_put(dev); rc = -EEXIST; - goto out; + goto err; } strlcpy(name, cfg->ifname, IFNAMSIZ); } else @@ -242,28 +295,24 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p session = l2tp_session_create(sizeof(*spriv), tunnel, session_id, peer_session_id, cfg); - if (!session) { - rc = -ENOMEM; - goto out; + if (IS_ERR(session)) { + rc = PTR_ERR(session); + goto err; } dev = alloc_netdev(sizeof(*priv), name, NET_NAME_UNKNOWN, l2tp_eth_dev_setup); if (!dev) { rc = -ENOMEM; - goto out_del_session; + goto err_sess; } dev_net_set(dev, net); - if (session->mtu == 0) - session->mtu = dev->mtu - session->hdr_len; - dev->mtu = session->mtu; - dev->needed_headroom += session->hdr_len; + l2tp_eth_adjust_mtu(tunnel, session, dev); priv = netdev_priv(dev); priv->dev = dev; priv->session = session; - INIT_LIST_HEAD(&priv->list); priv->tunnel_sock = tunnel->sock; session->recv_skb = l2tp_eth_dev_recv; @@ -273,48 +322,50 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p #endif spriv = l2tp_session_priv(session); - spriv->dev = dev; - rc = register_netdev(dev); - if (rc < 0) - goto out_del_dev; + l2tp_session_inc_refcount(session); - __module_get(THIS_MODULE); - /* Must be done after register_netdev() */ - strlcpy(session->ifname, dev->name, IFNAMSIZ); + rtnl_lock(); - dev_hold(dev); - pn = l2tp_eth_pernet(dev_net(dev)); - spin_lock(&pn->l2tp_eth_lock); - list_add(&priv->list, &pn->l2tp_eth_dev_list); - spin_unlock(&pn->l2tp_eth_lock); + /* Register both device and session while holding the rtnl lock. This + * ensures that l2tp_eth_delete() will see that there's a device to + * unregister, even if it happened to run before we assign spriv->dev. + */ + rc = l2tp_session_register(session, tunnel); + if (rc < 0) { + rtnl_unlock(); + goto err_sess_dev; + } - return 0; + rc = register_netdevice(dev); + if (rc < 0) { + rtnl_unlock(); + l2tp_session_delete(session); + l2tp_session_dec_refcount(session); + free_netdev(dev); -out_del_dev: - free_netdev(dev); - spriv->dev = NULL; -out_del_session: - l2tp_session_delete(session); -out: - return rc; -} + return rc; + } -static __net_init int l2tp_eth_init_net(struct net *net) -{ - struct l2tp_eth_net *pn = net_generic(net, l2tp_eth_net_id); + strlcpy(session->ifname, dev->name, IFNAMSIZ); + rcu_assign_pointer(spriv->dev, dev); - INIT_LIST_HEAD(&pn->l2tp_eth_dev_list); - spin_lock_init(&pn->l2tp_eth_lock); + rtnl_unlock(); + + l2tp_session_dec_refcount(session); + + __module_get(THIS_MODULE); return 0; -} -static struct pernet_operations l2tp_eth_net_ops = { - .init = l2tp_eth_init_net, - .id = &l2tp_eth_net_id, - .size = sizeof(struct l2tp_eth_net), -}; +err_sess_dev: + l2tp_session_dec_refcount(session); + free_netdev(dev); +err_sess: + kfree(session); +err: + return rc; +} static const struct l2tp_nl_cmd_ops l2tp_eth_nl_cmd_ops = { @@ -329,25 +380,18 @@ static int __init l2tp_eth_init(void) err = l2tp_nl_register_ops(L2TP_PWTYPE_ETH, &l2tp_eth_nl_cmd_ops); if (err) - goto out; - - err = register_pernet_device(&l2tp_eth_net_ops); - if (err) - goto out_unreg; + goto err; pr_info("L2TP ethernet pseudowire support (L2TPv3)\n"); return 0; -out_unreg: - l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); -out: +err: return err; } static void __exit l2tp_eth_exit(void) { - unregister_pernet_device(&l2tp_eth_net_ops); l2tp_nl_unregister_ops(L2TP_PWTYPE_ETH); } diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 7efb3cadc152..3a31370d568a 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -24,7 +24,6 @@ #include <net/icmp.h> #include <net/udp.h> #include <net/inet_common.h> -#include <net/inet_hashtables.h> #include <net/tcp_states.h> #include <net/protocol.h> #include <net/xfrm.h> @@ -122,6 +121,7 @@ static int l2tp_ip_recv(struct sk_buff *skb) unsigned char *ptr, *optr; struct l2tp_session *session; struct l2tp_tunnel *tunnel = NULL; + struct iphdr *iph; int length; if (!pskb_may_pull(skb, 4)) @@ -142,19 +142,19 @@ static int l2tp_ip_recv(struct sk_buff *skb) } /* Ok, this is a data packet. Lookup the session. */ - session = l2tp_session_find(net, NULL, session_id); - if (session == NULL) + session = l2tp_session_get(net, NULL, session_id, true); + if (!session) goto discard; tunnel = session->tunnel; - if (tunnel == NULL) - goto discard; + if (!tunnel) + goto discard_sess; /* Trace packet contents, if enabled */ if (tunnel->debug & L2TP_MSG_DATA) { length = min(32u, skb->len); if (!pskb_may_pull(skb, length)) - goto discard; + goto discard_sess; /* Point to L2TP header */ optr = ptr = skb->data; @@ -167,6 +167,7 @@ static int l2tp_ip_recv(struct sk_buff *skb) goto discard; l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); + l2tp_session_dec_refcount(session); return 0; @@ -179,23 +180,16 @@ pass_up: goto discard; tunnel_id = ntohl(*(__be32 *) &skb->data[4]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel) { - sk = tunnel->sock; - sock_hold(sk); - } else { - struct iphdr *iph = (struct iphdr *) skb_network_header(skb); + iph = (struct iphdr *)skb_network_header(skb); - read_lock_bh(&l2tp_ip_lock); - sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id); - if (!sk) { - read_unlock_bh(&l2tp_ip_lock); - goto discard; - } - - sock_hold(sk); + read_lock_bh(&l2tp_ip_lock); + sk = __l2tp_ip_bind_lookup(net, iph->daddr, 0, tunnel_id); + if (!sk) { read_unlock_bh(&l2tp_ip_lock); + goto discard; } + sock_hold(sk); + read_unlock_bh(&l2tp_ip_lock); if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) goto discard_put; @@ -204,6 +198,12 @@ pass_up: return sk_receive_skb(sk, skb, 1); +discard_sess: + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + goto discard; + discard_put: sock_put(sk); @@ -212,15 +212,31 @@ discard: return 0; } -static int l2tp_ip_open(struct sock *sk) +static int l2tp_ip_hash(struct sock *sk) { - /* Prevent autobind. We don't have ports. */ - inet_sk(sk)->inet_num = IPPROTO_L2TP; + if (sk_unhashed(sk)) { + write_lock_bh(&l2tp_ip_lock); + sk_add_node(sk, &l2tp_ip_table); + write_unlock_bh(&l2tp_ip_lock); + } + return 0; +} +static void l2tp_ip_unhash(struct sock *sk) +{ + if (sk_unhashed(sk)) + return; write_lock_bh(&l2tp_ip_lock); - sk_add_node(sk, &l2tp_ip_table); + sk_del_node_init(sk); write_unlock_bh(&l2tp_ip_lock); +} +static int l2tp_ip_open(struct sock *sk) +{ + /* Prevent autobind. We don't have ports. */ + inet_sk(sk)->inet_num = IPPROTO_L2TP; + + l2tp_ip_hash(sk); return 0; } @@ -262,15 +278,9 @@ static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) if (addr->l2tp_family != AF_INET) return -EINVAL; - ret = -EADDRINUSE; - read_lock_bh(&l2tp_ip_lock); - if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, - sk->sk_bound_dev_if, addr->l2tp_conn_id)) - goto out_in_use; - - read_unlock_bh(&l2tp_ip_lock); - lock_sock(sk); + + ret = -EINVAL; if (!sock_flag(sk, SOCK_ZAPPED)) goto out; @@ -287,14 +297,22 @@ static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) inet->inet_saddr = 0; /* Use device */ - sk_dst_reset(sk); + write_lock_bh(&l2tp_ip_lock); + if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, + sk->sk_bound_dev_if, addr->l2tp_conn_id)) { + write_unlock_bh(&l2tp_ip_lock); + ret = -EADDRINUSE; + goto out; + } + + sk_dst_reset(sk); l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; - write_lock_bh(&l2tp_ip_lock); sk_add_bind_node(sk, &l2tp_ip_bind_table); sk_del_node_init(sk); write_unlock_bh(&l2tp_ip_lock); + ret = 0; sock_reset_flag(sk, SOCK_ZAPPED); @@ -302,11 +320,6 @@ out: release_sock(sk); return ret; - -out_in_use: - read_unlock_bh(&l2tp_ip_lock); - - return ret; } static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) @@ -314,21 +327,24 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; int rc; - if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ - return -EINVAL; - if (addr_len < sizeof(*lsa)) return -EINVAL; if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) return -EINVAL; - rc = ip4_datagram_connect(sk, uaddr, addr_len); - if (rc < 0) - return rc; - lock_sock(sk); + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip4_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip_lock); @@ -336,7 +352,9 @@ static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len sk_add_bind_node(sk, &l2tp_ip_bind_table); write_unlock_bh(&l2tp_ip_lock); +out_sk: release_sock(sk); + return rc; } @@ -600,8 +618,8 @@ static struct proto l2tp_ip_prot = { .sendmsg = l2tp_ip_sendmsg, .recvmsg = l2tp_ip_recvmsg, .backlog_rcv = l2tp_ip_backlog_recv, - .hash = inet_hash, - .unhash = inet_unhash, + .hash = l2tp_ip_hash, + .unhash = l2tp_ip_unhash, .obj_size = sizeof(struct l2tp_ip_sock), #ifdef CONFIG_COMPAT .compat_setsockopt = compat_ip_setsockopt, diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index c125478981ac..1a8a4e451a5f 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -24,7 +24,6 @@ #include <net/icmp.h> #include <net/udp.h> #include <net/inet_common.h> -#include <net/inet_hashtables.h> #include <net/tcp_states.h> #include <net/protocol.h> #include <net/xfrm.h> @@ -127,12 +126,14 @@ static inline struct sock *l2tp_ip6_bind_lookup(struct net *net, */ static int l2tp_ip6_recv(struct sk_buff *skb) { + struct net *net = dev_net(skb->dev); struct sock *sk; u32 session_id; u32 tunnel_id; unsigned char *ptr, *optr; struct l2tp_session *session; struct l2tp_tunnel *tunnel = NULL; + struct ipv6hdr *iph; int length; if (!pskb_may_pull(skb, 4)) @@ -153,19 +154,19 @@ static int l2tp_ip6_recv(struct sk_buff *skb) } /* Ok, this is a data packet. Lookup the session. */ - session = l2tp_session_find(&init_net, NULL, session_id); - if (session == NULL) + session = l2tp_session_get(net, NULL, session_id, true); + if (!session) goto discard; tunnel = session->tunnel; - if (tunnel == NULL) - goto discard; + if (!tunnel) + goto discard_sess; /* Trace packet contents, if enabled */ if (tunnel->debug & L2TP_MSG_DATA) { length = min(32u, skb->len); if (!pskb_may_pull(skb, length)) - goto discard; + goto discard_sess; /* Point to L2TP header */ optr = ptr = skb->data; @@ -179,6 +180,8 @@ static int l2tp_ip6_recv(struct sk_buff *skb) l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); + l2tp_session_dec_refcount(session); + return 0; pass_up: @@ -190,24 +193,16 @@ pass_up: goto discard; tunnel_id = ntohl(*(__be32 *) &skb->data[4]); - tunnel = l2tp_tunnel_find(&init_net, tunnel_id); - if (tunnel) { - sk = tunnel->sock; - sock_hold(sk); - } else { - struct ipv6hdr *iph = ipv6_hdr(skb); - - read_lock_bh(&l2tp_ip6_lock); - sk = __l2tp_ip6_bind_lookup(&init_net, &iph->daddr, - 0, tunnel_id); - if (!sk) { - read_unlock_bh(&l2tp_ip6_lock); - goto discard; - } + iph = ipv6_hdr(skb); - sock_hold(sk); + read_lock_bh(&l2tp_ip6_lock); + sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, 0, tunnel_id); + if (!sk) { read_unlock_bh(&l2tp_ip6_lock); + goto discard; } + sock_hold(sk); + read_unlock_bh(&l2tp_ip6_lock); if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb)) goto discard_put; @@ -216,6 +211,12 @@ pass_up: return sk_receive_skb(sk, skb, 1); +discard_sess: + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + goto discard; + discard_put: sock_put(sk); @@ -224,15 +225,31 @@ discard: return 0; } -static int l2tp_ip6_open(struct sock *sk) +static int l2tp_ip6_hash(struct sock *sk) { - /* Prevent autobind. We don't have ports. */ - inet_sk(sk)->inet_num = IPPROTO_L2TP; + if (sk_unhashed(sk)) { + write_lock_bh(&l2tp_ip6_lock); + sk_add_node(sk, &l2tp_ip6_table); + write_unlock_bh(&l2tp_ip6_lock); + } + return 0; +} +static void l2tp_ip6_unhash(struct sock *sk) +{ + if (sk_unhashed(sk)) + return; write_lock_bh(&l2tp_ip6_lock); - sk_add_node(sk, &l2tp_ip6_table); + sk_del_node_init(sk); write_unlock_bh(&l2tp_ip6_lock); +} + +static int l2tp_ip6_open(struct sock *sk) +{ + /* Prevent autobind. We don't have ports. */ + inet_sk(sk)->inet_num = IPPROTO_L2TP; + l2tp_ip6_hash(sk); return 0; } @@ -267,7 +284,9 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; + struct net *net = sock_net(sk); __be32 v4addr = 0; + int bound_dev_if; int addr_type; int err; @@ -286,13 +305,6 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) if (addr_type & IPV6_ADDR_MULTICAST) return -EADDRNOTAVAIL; - err = -EADDRINUSE; - read_lock_bh(&l2tp_ip6_lock); - if (__l2tp_ip6_bind_lookup(&init_net, &addr->l2tp_addr, - sk->sk_bound_dev_if, addr->l2tp_conn_id)) - goto out_in_use; - read_unlock_bh(&l2tp_ip6_lock); - lock_sock(sk); err = -EINVAL; @@ -302,28 +314,25 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) if (sk->sk_state != TCP_CLOSE) goto out_unlock; + bound_dev_if = sk->sk_bound_dev_if; + /* Check if the address belongs to the host. */ rcu_read_lock(); if (addr_type != IPV6_ADDR_ANY) { struct net_device *dev = NULL; if (addr_type & IPV6_ADDR_LINKLOCAL) { - if (addr_len >= sizeof(struct sockaddr_in6) && - addr->l2tp_scope_id) { - /* Override any existing binding, if another - * one is supplied by user. - */ - sk->sk_bound_dev_if = addr->l2tp_scope_id; - } + if (addr->l2tp_scope_id) + bound_dev_if = addr->l2tp_scope_id; /* Binding to link-local address requires an - interface */ - if (!sk->sk_bound_dev_if) + * interface. + */ + if (!bound_dev_if) goto out_unlock_rcu; err = -ENODEV; - dev = dev_get_by_index_rcu(sock_net(sk), - sk->sk_bound_dev_if); + dev = dev_get_by_index_rcu(sock_net(sk), bound_dev_if); if (!dev) goto out_unlock_rcu; } @@ -338,13 +347,22 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) } rcu_read_unlock(); - inet->inet_rcv_saddr = inet->inet_saddr = v4addr; + write_lock_bh(&l2tp_ip6_lock); + if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if, + addr->l2tp_conn_id)) { + write_unlock_bh(&l2tp_ip6_lock); + err = -EADDRINUSE; + goto out_unlock; + } + + inet->inet_saddr = v4addr; + inet->inet_rcv_saddr = v4addr; + sk->sk_bound_dev_if = bound_dev_if; sk->sk_v6_rcv_saddr = addr->l2tp_addr; np->saddr = addr->l2tp_addr; l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; - write_lock_bh(&l2tp_ip6_lock); sk_add_bind_node(sk, &l2tp_ip6_bind_table); sk_del_node_init(sk); write_unlock_bh(&l2tp_ip6_lock); @@ -357,10 +375,7 @@ out_unlock_rcu: rcu_read_unlock(); out_unlock: release_sock(sk); - return err; -out_in_use: - read_unlock_bh(&l2tp_ip6_lock); return err; } @@ -373,9 +388,6 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_type; int rc; - if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ - return -EINVAL; - if (addr_len < sizeof(*lsa)) return -EINVAL; @@ -392,10 +404,18 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, return -EINVAL; } - rc = ip6_datagram_connect(sk, uaddr, addr_len); - lock_sock(sk); + /* Must bind first - autobinding does not work */ + if (sock_flag(sk, SOCK_ZAPPED)) { + rc = -EINVAL; + goto out_sk; + } + + rc = __ip6_datagram_connect(sk, uaddr, addr_len); + if (rc < 0) + goto out_sk; + l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip6_lock); @@ -403,6 +423,7 @@ static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, sk_add_bind_node(sk, &l2tp_ip6_bind_table); write_unlock_bh(&l2tp_ip6_lock); +out_sk: release_sock(sk); return rc; @@ -461,7 +482,7 @@ static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) return 0; drop: - IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_INDISCARDS); kfree_skb(skb); return -1; } @@ -608,9 +629,9 @@ static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) else if (!fl6.flowi6_oif) fl6.flowi6_oif = np->ucast_oif; - security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); + security_sk_classify_flow(sk, flowi6_to_flowi_common(&fl6)); - dst = ip6_dst_lookup_flow(sk, &fl6, final_p); + dst = ip6_dst_lookup_flow(sock_net(sk), sk, &fl6, final_p); if (IS_ERR(dst)) { err = PTR_ERR(dst); goto out; @@ -725,8 +746,8 @@ static struct proto l2tp_ip6_prot = { .sendmsg = l2tp_ip6_sendmsg, .recvmsg = l2tp_ip6_recvmsg, .backlog_rcv = l2tp_ip6_backlog_recv, - .hash = inet_hash, - .unhash = inet_unhash, + .hash = l2tp_ip6_hash, + .unhash = l2tp_ip6_unhash, .obj_size = sizeof(struct l2tp_ip6_sock), #ifdef CONFIG_COMPAT .compat_setsockopt = compat_ipv6_setsockopt, diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index fb3248ff8b48..d3a84a181348 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -55,7 +55,8 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, /* Accessed under genl lock */ static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX]; -static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info) +static struct l2tp_session *l2tp_nl_session_get(struct genl_info *info, + bool do_ref) { u32 tunnel_id; u32 session_id; @@ -66,14 +67,17 @@ static struct l2tp_session *l2tp_nl_session_find(struct genl_info *info) if (info->attrs[L2TP_ATTR_IFNAME]) { ifname = nla_data(info->attrs[L2TP_ATTR_IFNAME]); - session = l2tp_session_find_by_ifname(net, ifname); + session = l2tp_session_get_by_ifname(net, ifname, do_ref); } else if ((info->attrs[L2TP_ATTR_SESSION_ID]) && (info->attrs[L2TP_ATTR_CONN_ID])) { tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel) - session = l2tp_session_find(net, tunnel, session_id); + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (tunnel) { + session = l2tp_session_get(net, tunnel, session_id, + do_ref); + l2tp_tunnel_dec_refcount(tunnel); + } } return session; @@ -276,8 +280,8 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info } tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel == NULL) { + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { ret = -ENODEV; goto out; } @@ -287,6 +291,8 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info l2tp_tunnel_delete(tunnel); + l2tp_tunnel_dec_refcount(tunnel); + out: return ret; } @@ -304,8 +310,8 @@ static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info } tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel == NULL) { + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { ret = -ENODEV; goto out; } @@ -316,6 +322,8 @@ static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info ret = l2tp_tunnel_notify(&l2tp_nl_family, info, tunnel, L2TP_CMD_TUNNEL_MODIFY); + l2tp_tunnel_dec_refcount(tunnel); + out: return ret; } @@ -420,34 +428,37 @@ static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info) if (!info->attrs[L2TP_ATTR_CONN_ID]) { ret = -EINVAL; - goto out; + goto err; } tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); - if (tunnel == NULL) { - ret = -ENODEV; - goto out; - } - msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) { ret = -ENOMEM; - goto out; + goto err; + } + + tunnel = l2tp_tunnel_get(net, tunnel_id); + if (!tunnel) { + ret = -ENODEV; + goto err_nlmsg; } ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET); if (ret < 0) - goto err_out; + goto err_nlmsg_tunnel; + + l2tp_tunnel_dec_refcount(tunnel); return genlmsg_unicast(net, msg, info->snd_portid); -err_out: +err_nlmsg_tunnel: + l2tp_tunnel_dec_refcount(tunnel); +err_nlmsg: nlmsg_free(msg); - -out: +err: return ret; } @@ -491,8 +502,9 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf ret = -EINVAL; goto out; } + tunnel_id = nla_get_u32(info->attrs[L2TP_ATTR_CONN_ID]); - tunnel = l2tp_tunnel_find(net, tunnel_id); + tunnel = l2tp_tunnel_get(net, tunnel_id); if (!tunnel) { ret = -ENODEV; goto out; @@ -500,29 +512,24 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf if (!info->attrs[L2TP_ATTR_SESSION_ID]) { ret = -EINVAL; - goto out; + goto out_tunnel; } session_id = nla_get_u32(info->attrs[L2TP_ATTR_SESSION_ID]); - session = l2tp_session_find(net, tunnel, session_id); - if (session) { - ret = -EEXIST; - goto out; - } if (!info->attrs[L2TP_ATTR_PEER_SESSION_ID]) { ret = -EINVAL; - goto out; + goto out_tunnel; } peer_session_id = nla_get_u32(info->attrs[L2TP_ATTR_PEER_SESSION_ID]); if (!info->attrs[L2TP_ATTR_PW_TYPE]) { ret = -EINVAL; - goto out; + goto out_tunnel; } cfg.pw_type = nla_get_u16(info->attrs[L2TP_ATTR_PW_TYPE]); if (cfg.pw_type >= __L2TP_PWTYPE_MAX) { ret = -EINVAL; - goto out; + goto out_tunnel; } if (tunnel->version > 2) { @@ -544,7 +551,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf u16 len = nla_len(info->attrs[L2TP_ATTR_COOKIE]); if (len > 8) { ret = -EINVAL; - goto out; + goto out_tunnel; } cfg.cookie_len = len; memcpy(&cfg.cookie[0], nla_data(info->attrs[L2TP_ATTR_COOKIE]), len); @@ -553,7 +560,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf u16 len = nla_len(info->attrs[L2TP_ATTR_PEER_COOKIE]); if (len > 8) { ret = -EINVAL; - goto out; + goto out_tunnel; } cfg.peer_cookie_len = len; memcpy(&cfg.peer_cookie[0], nla_data(info->attrs[L2TP_ATTR_PEER_COOKIE]), len); @@ -596,7 +603,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf if ((l2tp_nl_cmd_ops[cfg.pw_type] == NULL) || (l2tp_nl_cmd_ops[cfg.pw_type]->session_create == NULL)) { ret = -EPROTONOSUPPORT; - goto out; + goto out_tunnel; } /* Check that pseudowire-specific params are present */ @@ -606,7 +613,7 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf case L2TP_PWTYPE_ETH_VLAN: if (!info->attrs[L2TP_ATTR_VLAN_ID]) { ret = -EINVAL; - goto out; + goto out_tunnel; } break; case L2TP_PWTYPE_ETH: @@ -620,18 +627,22 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf break; } - ret = -EPROTONOSUPPORT; - if (l2tp_nl_cmd_ops[cfg.pw_type]->session_create) - ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id, - session_id, peer_session_id, &cfg); + ret = l2tp_nl_cmd_ops[cfg.pw_type]->session_create(net, tunnel, + session_id, + peer_session_id, + &cfg); if (ret >= 0) { - session = l2tp_session_find(net, tunnel, session_id); - if (session) + session = l2tp_session_get(net, tunnel, session_id, false); + if (session) { ret = l2tp_session_notify(&l2tp_nl_family, info, session, L2TP_CMD_SESSION_CREATE); + l2tp_session_dec_refcount(session); + } } +out_tunnel: + l2tp_tunnel_dec_refcount(tunnel); out: return ret; } @@ -642,7 +653,7 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf struct l2tp_session *session; u16 pw_type; - session = l2tp_nl_session_find(info); + session = l2tp_nl_session_get(info, true); if (session == NULL) { ret = -ENODEV; goto out; @@ -656,6 +667,10 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete) ret = (*l2tp_nl_cmd_ops[pw_type]->session_delete)(session); + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + out: return ret; } @@ -665,7 +680,7 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf int ret = 0; struct l2tp_session *session; - session = l2tp_nl_session_find(info); + session = l2tp_nl_session_get(info, false); if (session == NULL) { ret = -ENODEV; goto out; @@ -700,6 +715,8 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf ret = l2tp_session_notify(&l2tp_nl_family, info, session, L2TP_CMD_SESSION_MODIFY); + l2tp_session_dec_refcount(session); + out: return ret; } @@ -786,29 +803,34 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info) struct sk_buff *msg; int ret; - session = l2tp_nl_session_find(info); + session = l2tp_nl_session_get(info, false); if (session == NULL) { ret = -ENODEV; - goto out; + goto err; } msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); if (!msg) { ret = -ENOMEM; - goto out; + goto err_ref; } ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq, 0, session, L2TP_CMD_SESSION_GET); if (ret < 0) - goto err_out; + goto err_ref_msg; - return genlmsg_unicast(genl_info_net(info), msg, info->snd_portid); + ret = genlmsg_unicast(genl_info_net(info), msg, info->snd_portid); -err_out: - nlmsg_free(msg); + l2tp_session_dec_refcount(session); -out: + return ret; + +err_ref_msg: + nlmsg_free(msg); +err_ref: + l2tp_session_dec_refcount(session); +err: return ret; } diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index d3f1222c1a8c..8ff5352bb0e3 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -122,8 +122,11 @@ struct pppol2tp_session { int owner; /* pid that opened the socket */ - struct sock *sock; /* Pointer to the session + struct mutex sk_lock; /* Protects .sk */ + struct sock __rcu *sk; /* Pointer to the session * PPPoX socket */ + struct sock *__sk; /* Copy of .sk, for cleanup */ + struct rcu_head rcu; /* For asynchronous release */ struct sock *tunnel_sock; /* Pointer to the tunnel UDP * socket */ int flags; /* accessed by PPPIOCGFLAGS. @@ -138,6 +141,24 @@ static const struct ppp_channel_ops pppol2tp_chan_ops = { static const struct proto_ops pppol2tp_ops; +/* Retrieves the pppol2tp socket associated to a session. + * A reference is held on the returned socket, so this function must be paired + * with sock_put(). + */ +static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session) +{ + struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk; + + rcu_read_lock(); + sk = rcu_dereference(ps->sk); + if (sk) + sock_hold(sk); + rcu_read_unlock(); + + return sk; +} + /* Helpers to obtain tunnel/session contexts from sockets. */ static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) @@ -177,7 +198,7 @@ static int pppol2tp_recv_payload_hook(struct sk_buff *skb) if (!pskb_may_pull(skb, 2)) return 1; - if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) + if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI)) skb_pull(skb, 2); return 0; @@ -224,13 +245,14 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int /* If the socket is bound, send it in to PPP's input queue. Otherwise * queue it on the session socket. */ - sk = ps->sock; + rcu_read_lock(); + sk = rcu_dereference(ps->sk); if (sk == NULL) goto no_sock; if (sk->sk_state & PPPOX_BOUND) { struct pppox_sock *po; - l2tp_dbg(session, PPPOL2TP_MSG_DATA, + l2tp_dbg(session, L2TP_MSG_DATA, "%s: recv %d byte data frame, passing to ppp\n", session->name, data_len); @@ -253,7 +275,7 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int po = pppox_sk(sk); ppp_input(&po->chan, skb); } else { - l2tp_dbg(session, PPPOL2TP_MSG_DATA, + l2tp_dbg(session, L2TP_MSG_DATA, "%s: recv %d byte data frame, passing to L2TP socket\n", session->name, data_len); @@ -262,30 +284,16 @@ static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int kfree_skb(skb); } } + rcu_read_unlock(); return; no_sock: - l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name); + rcu_read_unlock(); + l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name); kfree_skb(skb); } -static void pppol2tp_session_sock_hold(struct l2tp_session *session) -{ - struct pppol2tp_session *ps = l2tp_session_priv(session); - - if (ps->sock) - sock_hold(ps->sock); -} - -static void pppol2tp_session_sock_put(struct l2tp_session *session) -{ - struct pppol2tp_session *ps = l2tp_session_priv(session); - - if (ps->sock) - sock_put(ps->sock); -} - /************************************************************************ * Transmit handling ***********************************************************************/ @@ -297,7 +305,6 @@ static void pppol2tp_session_sock_put(struct l2tp_session *session) static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len) { - static const unsigned char ppph[2] = { 0xff, 0x03 }; struct sock *sk = sock->sk; struct sk_buff *skb; int error; @@ -327,7 +334,7 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, error = -ENOMEM; skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len + - sizeof(ppph) + total_len, + 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ 0, GFP_KERNEL); if (!skb) goto error_put_sess_tun; @@ -340,8 +347,8 @@ static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, skb_reserve(skb, uhlen); /* Add PPP header */ - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; + skb->data[0] = PPP_ALLSTATIONS; + skb->data[1] = PPP_UI; skb_put(skb, 2); /* Copy user data into skb */ @@ -384,7 +391,6 @@ error: */ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) { - static const u8 ppph[2] = { 0xff, 0x03 }; struct sock *sk = (struct sock *) chan->private; struct sock *sk_tun; struct l2tp_session *session; @@ -413,14 +419,14 @@ static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) sizeof(struct iphdr) + /* IP header */ uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ session->hdr_len + /* L2TP header */ - sizeof(ppph); /* PPP header */ + 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ if (skb_cow_head(skb, headroom)) goto abort_put_sess_tun; /* Setup PPP header */ - __skb_push(skb, sizeof(ppph)); - skb->data[0] = ppph[0]; - skb->data[1] = ppph[1]; + __skb_push(skb, 2); + skb->data[0] = PPP_ALLSTATIONS; + skb->data[1] = PPP_UI; local_bh_disable(); l2tp_xmit_skb(session, skb, session->hdr_len); @@ -448,16 +454,15 @@ abort: */ static void pppol2tp_session_close(struct l2tp_session *session) { - struct pppol2tp_session *ps = l2tp_session_priv(session); - struct sock *sk = ps->sock; - struct socket *sock = sk->sk_socket; + struct sock *sk; BUG_ON(session->magic != L2TP_SESSION_MAGIC); - if (sock) { - inet_shutdown(sock, 2); - /* Don't let the session go away before our socket does */ - l2tp_session_inc_refcount(session); + sk = pppol2tp_session_get_sock(session); + if (sk) { + if (sk->sk_socket) + inet_shutdown(sk->sk_socket, SEND_SHUTDOWN); + sock_put(sk); } } @@ -478,6 +483,14 @@ static void pppol2tp_session_destruct(struct sock *sk) } } +static void pppol2tp_put_sk(struct rcu_head *head) +{ + struct pppol2tp_session *ps; + + ps = container_of(head, typeof(*ps), rcu); + sock_put(ps->__sk); +} + /* Called when the PPPoX socket (session) is closed. */ static int pppol2tp_release(struct socket *sock) @@ -503,11 +516,23 @@ static int pppol2tp_release(struct socket *sock) session = pppol2tp_sock_to_session(sk); - /* Purge any queued data */ if (session != NULL) { - __l2tp_session_unhash(session); - l2tp_session_queue_purge(session); - sock_put(sk); + struct pppol2tp_session *ps; + + l2tp_session_delete(session); + + ps = l2tp_session_priv(session); + mutex_lock(&ps->sk_lock); + ps->__sk = rcu_dereference_protected(ps->sk, + lockdep_is_held(&ps->sk_lock)); + RCU_INIT_POINTER(ps->sk, NULL); + mutex_unlock(&ps->sk_lock); + call_rcu(&ps->rcu, pppol2tp_put_sk); + + /* Rely on the sock_put() call at the end of the function for + * dropping the reference held by pppol2tp_sock_to_session(). + * The last reference will be dropped by pppol2tp_put_sk(). + */ } release_sock(sk); @@ -574,16 +599,47 @@ out: static void pppol2tp_show(struct seq_file *m, void *arg) { struct l2tp_session *session = arg; - struct pppol2tp_session *ps = l2tp_session_priv(session); + struct sock *sk; + + sk = pppol2tp_session_get_sock(session); + if (sk) { + struct pppox_sock *po = pppox_sk(sk); - if (ps) { - struct pppox_sock *po = pppox_sk(ps->sock); - if (po) - seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + sock_put(sk); } } #endif +static void pppol2tp_session_init(struct l2tp_session *session) +{ + struct pppol2tp_session *ps; + struct dst_entry *dst; + + session->recv_skb = pppol2tp_recv; + session->session_close = pppol2tp_session_close; +#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) + session->show = pppol2tp_show; +#endif + + ps = l2tp_session_priv(session); + mutex_init(&ps->sk_lock); + ps->tunnel_sock = session->tunnel->sock; + ps->owner = current->pid; + + /* If PMTU discovery was enabled, use the MTU that was discovered */ + dst = sk_dst_get(session->tunnel->sock); + if (dst) { + u32 pmtu = dst_mtu(dst); + + if (pmtu) { + session->mtu = pmtu - PPPOL2TP_HEADER_OVERHEAD; + session->mru = pmtu - PPPOL2TP_HEADER_OVERHEAD; + } + dst_release(dst); + } +} + /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket */ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, @@ -595,11 +651,11 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, struct l2tp_session *session = NULL; struct l2tp_tunnel *tunnel; struct pppol2tp_session *ps; - struct dst_entry *dst; struct l2tp_session_cfg cfg = { 0, }; int error = 0; u32 tunnel_id, peer_tunnel_id; u32 session_id, peer_session_id; + bool drop_refcnt = false; int ver = 2; int fd; @@ -708,65 +764,53 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, if (tunnel->peer_tunnel_id == 0) tunnel->peer_tunnel_id = peer_tunnel_id; - /* Create session if it doesn't already exist. We handle the - * case where a session was previously created by the netlink - * interface by checking that the session doesn't already have - * a socket and its tunnel socket are what we expect. If any - * of those checks fail, return EEXIST to the caller. - */ - session = l2tp_session_find(sock_net(sk), tunnel, session_id); - if (session == NULL) { - /* Default MTU must allow space for UDP/L2TP/PPP - * headers. + session = l2tp_session_get(sock_net(sk), tunnel, session_id, false); + if (session) { + drop_refcnt = true; + ps = l2tp_session_priv(session); + + /* Using a pre-existing session is fine as long as it hasn't + * been connected yet. */ - cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; + mutex_lock(&ps->sk_lock); + if (rcu_dereference_protected(ps->sk, + lockdep_is_held(&ps->sk_lock))) { + mutex_unlock(&ps->sk_lock); + error = -EEXIST; + goto end; + } + + /* consistency checks */ + if (ps->tunnel_sock != tunnel->sock) { + mutex_unlock(&ps->sk_lock); + error = -EEXIST; + goto end; + } + } else { + /* Default MTU must allow space for UDP/L2TP/PPP headers */ + cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD; + cfg.mru = cfg.mtu; - /* Allocate and initialize a new session context. */ session = l2tp_session_create(sizeof(struct pppol2tp_session), tunnel, session_id, peer_session_id, &cfg); - if (session == NULL) { - error = -ENOMEM; + if (IS_ERR(session)) { + error = PTR_ERR(session); goto end; } - } else { + + pppol2tp_session_init(session); ps = l2tp_session_priv(session); - error = -EEXIST; - if (ps->sock != NULL) - goto end; + l2tp_session_inc_refcount(session); - /* consistency checks */ - if (ps->tunnel_sock != tunnel->sock) + mutex_lock(&ps->sk_lock); + error = l2tp_session_register(session, tunnel); + if (error < 0) { + mutex_unlock(&ps->sk_lock); + kfree(session); goto end; - } - - /* Associate session with its PPPoL2TP socket */ - ps = l2tp_session_priv(session); - ps->owner = current->pid; - ps->sock = sk; - ps->tunnel_sock = tunnel->sock; - - session->recv_skb = pppol2tp_recv; - session->session_close = pppol2tp_session_close; -#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) - session->show = pppol2tp_show; -#endif - - /* We need to know each time a skb is dropped from the reorder - * queue. - */ - session->ref = pppol2tp_session_sock_hold; - session->deref = pppol2tp_session_sock_put; - - /* If PMTU discovery was enabled, use the MTU that was discovered */ - dst = sk_dst_get(tunnel->sock); - if (dst != NULL) { - u32 pmtu = dst_mtu(dst); - - if (pmtu != 0) - session->mtu = session->mru = pmtu - - PPPOL2TP_HEADER_OVERHEAD; - dst_release(dst); + } + drop_refcnt = true; } /* Special case: if source & dest session_id == 0x0000, this @@ -791,17 +835,30 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, po->chan.mtu = session->mtu; error = ppp_register_net_channel(sock_net(sk), &po->chan); - if (error) + if (error) { + mutex_unlock(&ps->sk_lock); goto end; + } out_no_ppp: /* This is how we get the session context from the socket. */ sk->sk_user_data = session; + rcu_assign_pointer(ps->sk, sk); + mutex_unlock(&ps->sk_lock); + + /* Keep the reference we've grabbed on the session: sk doesn't expect + * the session to disappear. pppol2tp_session_destruct() is responsible + * for dropping it. + */ + drop_refcnt = false; + sk->sk_state = PPPOX_CONNECTED; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n", session->name); end: + if (drop_refcnt) + l2tp_session_dec_refcount(session); release_sock(sk); return error; @@ -809,31 +866,19 @@ end: #ifdef CONFIG_L2TP_V3 -/* Called when creating sessions via the netlink interface. - */ -static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) +/* Called when creating sessions via the netlink interface. */ +static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel, + u32 session_id, u32 peer_session_id, + struct l2tp_session_cfg *cfg) { int error; - struct l2tp_tunnel *tunnel; struct l2tp_session *session; - struct pppol2tp_session *ps; - - tunnel = l2tp_tunnel_find(net, tunnel_id); - - /* Error if we can't find the tunnel */ - error = -ENOENT; - if (tunnel == NULL) - goto out; /* Error if tunnel socket is not prepped */ - if (tunnel->sock == NULL) - goto out; - - /* Check that this session doesn't already exist */ - error = -EEXIST; - session = l2tp_session_find(net, tunnel, session_id); - if (session != NULL) - goto out; + if (!tunnel->sock) { + error = -ENOENT; + goto err; + } /* Default MTU values. */ if (cfg->mtu == 0) @@ -842,22 +887,25 @@ static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_i cfg->mru = cfg->mtu; /* Allocate and initialize a new session context. */ - error = -ENOMEM; session = l2tp_session_create(sizeof(struct pppol2tp_session), tunnel, session_id, peer_session_id, cfg); - if (session == NULL) - goto out; + if (IS_ERR(session)) { + error = PTR_ERR(session); + goto err; + } - ps = l2tp_session_priv(session); - ps->tunnel_sock = tunnel->sock; + pppol2tp_session_init(session); - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", - session->name); + error = l2tp_session_register(session, tunnel); + if (error < 0) + goto err_sess; - error = 0; + return 0; -out: +err_sess: + kfree(session); +err: return error; } @@ -889,10 +937,8 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, pls = l2tp_session_priv(session); tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock); - if (tunnel == NULL) { - error = -EBADF; + if (tunnel == NULL) goto end_put_sess; - } inet = inet_sk(tunnel->sock); if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) { @@ -970,12 +1016,11 @@ static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, } *usockaddr_len = len; + error = 0; sock_put(pls->tunnel_sock); end_put_sess: sock_put(sk); - error = 0; - end: return error; } @@ -1017,16 +1062,14 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, struct l2tp_tunnel *tunnel = session->tunnel; struct pppol2tp_ioc_stats stats; - l2tp_dbg(session, PPPOL2TP_MSG_CONTROL, + l2tp_dbg(session, L2TP_MSG_CONTROL, "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", session->name, cmd, arg); - sk = ps->sock; + sk = pppol2tp_session_get_sock(session); if (!sk) return -EBADR; - sock_hold(sk); - switch (cmd) { case SIOCGIFMTU: err = -ENXIO; @@ -1040,7 +1083,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) break; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n", session->name, session->mtu); err = 0; break; @@ -1056,7 +1099,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, session->mtu = ifr.ifr_mtu; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n", session->name, session->mtu); err = 0; break; @@ -1070,7 +1113,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, if (put_user(session->mru, (int __user *) arg)) break; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n", session->name, session->mru); err = 0; break; @@ -1085,7 +1128,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, break; session->mru = val; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n", session->name, session->mru); err = 0; break; @@ -1095,7 +1138,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, if (put_user(ps->flags, (int __user *) arg)) break; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n", session->name, ps->flags); err = 0; break; @@ -1105,7 +1148,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, if (get_user(val, (int __user *) arg)) break; ps->flags = val; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n", session->name, ps->flags); err = 0; break; @@ -1122,7 +1165,7 @@ static int pppol2tp_session_ioctl(struct l2tp_session *session, if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) break; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n", session->name); err = 0; break; @@ -1150,7 +1193,7 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, struct sock *sk; struct pppol2tp_ioc_stats stats; - l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL, + l2tp_dbg(tunnel, L2TP_MSG_CONTROL, "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name, cmd, arg); @@ -1171,11 +1214,18 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, if (stats.session_id != 0) { /* resend to session ioctl handler */ struct l2tp_session *session = - l2tp_session_find(sock_net(sk), tunnel, stats.session_id); - if (session != NULL) - err = pppol2tp_session_ioctl(session, cmd, arg); - else + l2tp_session_get(sock_net(sk), tunnel, + stats.session_id, true); + + if (session) { + err = pppol2tp_session_ioctl(session, cmd, + arg); + if (session->deref) + session->deref(session); + l2tp_session_dec_refcount(session); + } else { err = -EBADR; + } break; } #ifdef CONFIG_XFRM @@ -1186,7 +1236,7 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, err = -EFAULT; break; } - l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", + l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n", tunnel->name); err = 0; break; @@ -1276,7 +1326,7 @@ static int pppol2tp_tunnel_setsockopt(struct sock *sk, switch (optname) { case PPPOL2TP_SO_DEBUG: tunnel->debug = val; - l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", + l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n", tunnel->name, tunnel->debug); break; @@ -1295,7 +1345,6 @@ static int pppol2tp_session_setsockopt(struct sock *sk, int optname, int val) { int err = 0; - struct pppol2tp_session *ps = l2tp_session_priv(session); switch (optname) { case PPPOL2TP_SO_RECVSEQ: @@ -1304,7 +1353,7 @@ static int pppol2tp_session_setsockopt(struct sock *sk, break; } session->recv_seq = val ? -1 : 0; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set recv_seq=%d\n", session->name, session->recv_seq); break; @@ -1316,13 +1365,13 @@ static int pppol2tp_session_setsockopt(struct sock *sk, } session->send_seq = val ? -1 : 0; { - struct sock *ssk = ps->sock; - struct pppox_sock *po = pppox_sk(ssk); + struct pppox_sock *po = pppox_sk(sk); + po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; } l2tp_session_set_header_len(session, session->tunnel->version); - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set send_seq=%d\n", session->name, session->send_seq); break; @@ -1333,20 +1382,20 @@ static int pppol2tp_session_setsockopt(struct sock *sk, break; } session->lns_mode = val ? -1 : 0; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set lns_mode=%d\n", session->name, session->lns_mode); break; case PPPOL2TP_SO_DEBUG: session->debug = val; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n", session->name, session->debug); break; case PPPOL2TP_SO_REORDERTO: session->reorder_timeout = msecs_to_jiffies(val); - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: set reorder_timeout=%d\n", session->name, session->reorder_timeout); break; @@ -1427,7 +1476,7 @@ static int pppol2tp_tunnel_getsockopt(struct sock *sk, switch (optname) { case PPPOL2TP_SO_DEBUG: *val = tunnel->debug; - l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n", + l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n", tunnel->name, tunnel->debug); break; @@ -1450,31 +1499,31 @@ static int pppol2tp_session_getsockopt(struct sock *sk, switch (optname) { case PPPOL2TP_SO_RECVSEQ: *val = session->recv_seq; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get recv_seq=%d\n", session->name, *val); break; case PPPOL2TP_SO_SENDSEQ: *val = session->send_seq; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get send_seq=%d\n", session->name, *val); break; case PPPOL2TP_SO_LNSMODE: *val = session->lns_mode; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get lns_mode=%d\n", session->name, *val); break; case PPPOL2TP_SO_DEBUG: *val = session->debug; - l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n", + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n", session->name, *val); break; case PPPOL2TP_SO_REORDERTO: *val = (int) jiffies_to_msecs(session->reorder_timeout); - l2tp_info(session, PPPOL2TP_MSG_CONTROL, + l2tp_info(session, L2TP_MSG_CONTROL, "%s: get reorder_timeout=%d\n", session->name, *val); break; @@ -1653,8 +1702,9 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v) { struct l2tp_session *session = v; struct l2tp_tunnel *tunnel = session->tunnel; - struct pppol2tp_session *ps = l2tp_session_priv(session); - struct pppox_sock *po = pppox_sk(ps->sock); + unsigned char state; + char user_data_ok; + struct sock *sk; u32 ip = 0; u16 port = 0; @@ -1664,6 +1714,15 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v) port = ntohs(inet->inet_sport); } + sk = pppol2tp_session_get_sock(session); + if (sk) { + state = sk->sk_state; + user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N'; + } else { + state = 0; + user_data_ok = 'N'; + } + seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " "%04X/%04X %d %c\n", session->name, ip, port, @@ -1671,9 +1730,7 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v) session->session_id, tunnel->peer_tunnel_id, session->peer_session_id, - ps->sock->sk_state, - (session == ps->sock->sk_user_data) ? - 'Y' : 'N'); + state, user_data_ok); seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", session->mtu, session->mru, session->recv_seq ? 'R' : '-', @@ -1690,8 +1747,12 @@ static void pppol2tp_seq_session_show(struct seq_file *m, void *v) atomic_long_read(&session->stats.rx_bytes), atomic_long_read(&session->stats.rx_errors)); - if (po) + if (sk) { + struct pppox_sock *po = pppox_sk(sk); + seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + sock_put(sk); + } } static int pppol2tp_seq_show(struct seq_file *m, void *v) |