diff options
Diffstat (limited to 'net/l2tp/l2tp_core.c')
-rw-r--r-- | net/l2tp/l2tp_core.c | 619 |
1 files changed, 273 insertions, 346 deletions
diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index fcb53ed1c4fb..7499c51b1850 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1,6 +1,5 @@ // SPDX-License-Identifier: GPL-2.0-only -/* - * L2TP core. +/* L2TP core. * * Copyright (c) 2008,2009,2010 Katalix Systems Ltd * @@ -62,6 +61,10 @@ #include <linux/atomic.h> #include "l2tp_core.h" +#include "trace.h" + +#define CREATE_TRACE_POINTS +#include "trace.h" #define L2TP_DRV_VERSION "V2.0" @@ -94,7 +97,7 @@ struct l2tp_skb_cb { unsigned long expires; }; -#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) +#define L2TP_SKB_CB(skb) ((struct l2tp_skb_cb *)&(skb)->cb[sizeof(struct inet_skb_parm)]) static struct workqueue_struct *l2tp_wq; @@ -102,8 +105,10 @@ static struct workqueue_struct *l2tp_wq; static unsigned int l2tp_net_id; struct l2tp_net { struct list_head l2tp_tunnel_list; + /* Lock for write access to l2tp_tunnel_list */ spinlock_t l2tp_tunnel_list_lock; struct hlist_head l2tp_session_hlist[L2TP_HASH_SIZE_2]; + /* Lock for write access to l2tp_session_hlist */ spinlock_t l2tp_session_hlist_lock; }; @@ -115,11 +120,6 @@ static bool l2tp_sk_is_v6(struct sock *sk) } #endif -static inline struct l2tp_tunnel *l2tp_tunnel(struct sock *sk) -{ - return sk->sk_user_data; -} - static inline struct l2tp_net *l2tp_pernet(const struct net *net) { return net_generic(net, l2tp_net_id); @@ -134,7 +134,6 @@ static inline struct hlist_head * l2tp_session_id_hash_2(struct l2tp_net *pn, u32 session_id) { return &pn->l2tp_session_hlist[hash_32(session_id, L2TP_HASH_BITS_2)]; - } /* Session hash list. @@ -149,12 +148,58 @@ l2tp_session_id_hash(struct l2tp_tunnel *tunnel, u32 session_id) return &tunnel->session_hlist[hash_32(session_id, L2TP_HASH_BITS)]; } -void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) +static void l2tp_tunnel_free(struct l2tp_tunnel *tunnel) { + trace_free_tunnel(tunnel); sock_put(tunnel->sock); /* the tunnel is freed in the socket destructor */ } -EXPORT_SYMBOL(l2tp_tunnel_free); + +static void l2tp_session_free(struct l2tp_session *session) +{ + trace_free_session(session); + if (session->tunnel) + l2tp_tunnel_dec_refcount(session->tunnel); + kfree(session); +} + +struct l2tp_tunnel *l2tp_sk_to_tunnel(struct sock *sk) +{ + struct l2tp_tunnel *tunnel = sk->sk_user_data; + + if (tunnel) + if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) + return NULL; + + return tunnel; +} +EXPORT_SYMBOL_GPL(l2tp_sk_to_tunnel); + +void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) +{ + refcount_inc(&tunnel->ref_count); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_inc_refcount); + +void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) +{ + if (refcount_dec_and_test(&tunnel->ref_count)) + l2tp_tunnel_free(tunnel); +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_dec_refcount); + +void l2tp_session_inc_refcount(struct l2tp_session *session) +{ + refcount_inc(&session->ref_count); +} +EXPORT_SYMBOL_GPL(l2tp_session_inc_refcount); + +void l2tp_session_dec_refcount(struct l2tp_session *session) +{ + if (refcount_dec_and_test(&session->ref_count)) + l2tp_session_free(session); +} +EXPORT_SYMBOL_GPL(l2tp_session_dec_refcount); /* 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) @@ -205,15 +250,15 @@ struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, session_list = l2tp_session_id_hash(tunnel, session_id); - read_lock_bh(&tunnel->hlist_lock); - hlist_for_each_entry(session, session_list, hlist) + rcu_read_lock_bh(); + hlist_for_each_entry_rcu(session, session_list, hlist) if (session->session_id == session_id) { l2tp_session_inc_refcount(session); - read_unlock_bh(&tunnel->hlist_lock); + rcu_read_unlock_bh(); return session; } - read_unlock_bh(&tunnel->hlist_lock); + rcu_read_unlock_bh(); return NULL; } @@ -246,18 +291,18 @@ struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth) struct l2tp_session *session; int count = 0; - read_lock_bh(&tunnel->hlist_lock); + rcu_read_lock_bh(); for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { - hlist_for_each_entry(session, &tunnel->session_hlist[hash], hlist) { + hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { if (++count > nth) { l2tp_session_inc_refcount(session); - read_unlock_bh(&tunnel->hlist_lock); + rcu_read_unlock_bh(); return session; } } } - read_unlock_bh(&tunnel->hlist_lock); + rcu_read_unlock_bh(); return NULL; } @@ -302,7 +347,7 @@ int l2tp_session_register(struct l2tp_session *session, head = l2tp_session_id_hash(tunnel, session->session_id); - write_lock_bh(&tunnel->hlist_lock); + spin_lock_bh(&tunnel->hlist_lock); if (!tunnel->acpt_newsess) { err = -ENODEV; goto err_tlock; @@ -339,15 +384,17 @@ int l2tp_session_register(struct l2tp_session *session, l2tp_tunnel_inc_refcount(tunnel); } - hlist_add_head(&session->hlist, head); - write_unlock_bh(&tunnel->hlist_lock); + hlist_add_head_rcu(&session->hlist, head); + spin_unlock_bh(&tunnel->hlist_lock); + + trace_register_session(session); return 0; err_tlock_pnlock: spin_unlock_bh(&pn->l2tp_session_hlist_lock); err_tlock: - write_unlock_bh(&tunnel->hlist_lock); + spin_unlock_bh(&tunnel->hlist_lock); return err; } @@ -370,10 +417,6 @@ static void l2tp_recv_queue_skb(struct l2tp_session *session, struct sk_buff *sk skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { if (L2TP_SKB_CB(skbp)->ns > ns) { __skb_queue_before(&session->reorder_q, skbp, skb); - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", - session->name, ns, L2TP_SKB_CB(skbp)->ns, - skb_queue_len(&session->reorder_q)); atomic_long_inc(&session->stats.rx_oos_packets); goto out; } @@ -406,13 +449,11 @@ static void l2tp_recv_dequeue_skb(struct l2tp_session *session, struct sk_buff * /* Bump our Nr */ session->nr++; session->nr &= session->nr_max; - - l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated nr to %hu\n", - session->name, session->nr); + trace_session_seqnum_update(session); } /* call private receive handler */ - if (session->recv_skb != NULL) + if (session->recv_skb) (*session->recv_skb)(session, skb, L2TP_SKB_CB(skb)->length); else kfree_skb(skb); @@ -433,37 +474,27 @@ static void l2tp_recv_dequeue(struct l2tp_session *session) start: spin_lock_bh(&session->reorder_q.lock); skb_queue_walk_safe(&session->reorder_q, skb, tmp) { - if (time_after(jiffies, L2TP_SKB_CB(skb)->expires)) { + struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); + + /* If the packet has been pending on the queue for too long, discard it */ + if (time_after(jiffies, cb->expires)) { atomic_long_inc(&session->stats.rx_seq_discards); atomic_long_inc(&session->stats.rx_errors); - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: oos pkt %u len %d discarded (too old), waiting for %u, reorder_q_len=%d\n", - session->name, L2TP_SKB_CB(skb)->ns, - L2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); + trace_session_pkt_expired(session, cb->ns); session->reorder_skip = 1; __skb_unlink(skb, &session->reorder_q); kfree_skb(skb); continue; } - if (L2TP_SKB_CB(skb)->has_seq) { + if (cb->has_seq) { if (session->reorder_skip) { - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: advancing nr to next pkt: %u -> %u", - session->name, session->nr, - L2TP_SKB_CB(skb)->ns); session->reorder_skip = 0; - session->nr = L2TP_SKB_CB(skb)->ns; + session->nr = cb->ns; + trace_session_seqnum_reset(session); } - if (L2TP_SKB_CB(skb)->ns != session->nr) { - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: holding oos pkt %u len %d, waiting for %u, reorder_q_len=%d\n", - session->name, L2TP_SKB_CB(skb)->ns, - L2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); + if (cb->ns != session->nr) goto out; - } } __skb_unlink(skb, &session->reorder_q); @@ -496,14 +527,13 @@ static int l2tp_seq_check_rx_window(struct l2tp_session *session, u32 nr) */ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) { - if (!l2tp_seq_check_rx_window(session, L2TP_SKB_CB(skb)->ns)) { + struct l2tp_skb_cb *cb = L2TP_SKB_CB(skb); + + if (!l2tp_seq_check_rx_window(session, cb->ns)) { /* Packet sequence number is outside allowed window. * Discard it. */ - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: pkt %u len %d discarded, outside window, nr=%u\n", - session->name, L2TP_SKB_CB(skb)->ns, - L2TP_SKB_CB(skb)->length, session->nr); + trace_session_pkt_outside_rx_window(session, cb->ns); goto discard; } @@ -520,10 +550,10 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) * is seen. After nr_oos_count_max in-sequence packets, reset the * sequence number to re-enable packet reception. */ - if (L2TP_SKB_CB(skb)->ns == session->nr) { + if (cb->ns == session->nr) { skb_queue_tail(&session->reorder_q, skb); } else { - u32 nr_oos = L2TP_SKB_CB(skb)->ns; + u32 nr_oos = cb->ns; u32 nr_next = (session->nr_oos + 1) & session->nr_max; if (nr_oos == nr_next) @@ -534,17 +564,10 @@ static int l2tp_recv_data_seq(struct l2tp_session *session, struct sk_buff *skb) session->nr_oos = nr_oos; if (session->nr_oos_count > session->nr_oos_count_max) { session->reorder_skip = 1; - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: %d oos packets received. Resetting sequence numbers\n", - session->name, session->nr_oos_count); } if (!session->reorder_skip) { atomic_long_inc(&session->stats.rx_seq_discards); - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: oos pkt %u len %d discarded, waiting for %u, reorder_q_len=%d\n", - session->name, L2TP_SKB_CB(skb)->ns, - L2TP_SKB_CB(skb)->length, session->nr, - skb_queue_len(&session->reorder_q)); + trace_session_pkt_oos(session, cb->ns); goto discard; } skb_queue_tail(&session->reorder_q, skb); @@ -622,15 +645,13 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, { struct l2tp_tunnel *tunnel = session->tunnel; int offset; - u32 ns, nr; /* Parse and check optional cookie */ if (session->peer_cookie_len > 0) { if (memcmp(ptr, &session->peer_cookie[0], session->peer_cookie_len)) { - l2tp_info(tunnel, L2TP_MSG_DATA, - "%s: cookie mismatch (%u/%u). Discarding.\n", - tunnel->name, tunnel->tunnel_id, - session->session_id); + pr_debug_ratelimited("%s: cookie mismatch (%u/%u). Discarding.\n", + tunnel->name, tunnel->tunnel_id, + session->session_id); atomic_long_inc(&session->stats.rx_cookie_discards); goto discard; } @@ -644,49 +665,35 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, * the control of the LNS. If no sequence numbers present but * we were expecting them, discard frame. */ - ns = nr = 0; L2TP_SKB_CB(skb)->has_seq = 0; if (tunnel->version == L2TP_HDR_VER_2) { if (hdrflags & L2TP_HDRFLAG_S) { - ns = ntohs(*(__be16 *) ptr); - ptr += 2; - nr = ntohs(*(__be16 *) ptr); - ptr += 2; - /* Store L2TP info in the skb */ - L2TP_SKB_CB(skb)->ns = ns; + L2TP_SKB_CB(skb)->ns = ntohs(*(__be16 *)ptr); L2TP_SKB_CB(skb)->has_seq = 1; + ptr += 2; + /* Skip past nr in the header */ + ptr += 2; - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: recv data ns=%u, nr=%u, session nr=%u\n", - session->name, ns, nr, session->nr); } } else if (session->l2specific_type == L2TP_L2SPECTYPE_DEFAULT) { - u32 l2h = ntohl(*(__be32 *) ptr); + u32 l2h = ntohl(*(__be32 *)ptr); if (l2h & 0x40000000) { - ns = l2h & 0x00ffffff; - /* Store L2TP info in the skb */ - L2TP_SKB_CB(skb)->ns = ns; + L2TP_SKB_CB(skb)->ns = l2h & 0x00ffffff; L2TP_SKB_CB(skb)->has_seq = 1; - - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: recv data ns=%u, session nr=%u\n", - session->name, ns, session->nr); } ptr += 4; } if (L2TP_SKB_CB(skb)->has_seq) { - /* Received a packet with sequence numbers. If we're the LNS, + /* Received a packet with sequence numbers. If we're the LAC, * check if we sre sending sequence numbers and if not, * configure it so. */ - if ((!session->lns_mode) && (!session->send_seq)) { - l2tp_info(session, L2TP_MSG_SEQ, - "%s: requested to enable seq numbers by LNS\n", - session->name); + if (!session->lns_mode && !session->send_seq) { + trace_session_seqnum_lns_enable(session); session->send_seq = 1; l2tp_session_set_header_len(session, tunnel->version); } @@ -695,9 +702,8 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, * If user has configured mandatory sequence numbers, discard. */ if (session->recv_seq) { - l2tp_warn(session, L2TP_MSG_SEQ, - "%s: recv data has no seq numbers when required. Discarding.\n", - session->name); + pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", + session->name); atomic_long_inc(&session->stats.rx_seq_discards); goto discard; } @@ -707,16 +713,13 @@ void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, * If we're the LNS and we're sending sequence numbers, the * LAC is broken. Discard the frame. */ - if ((!session->lns_mode) && (session->send_seq)) { - l2tp_info(session, L2TP_MSG_SEQ, - "%s: requested to disable seq numbers by LNS\n", - session->name); + if (!session->lns_mode && session->send_seq) { + trace_session_seqnum_lns_disable(session); session->send_seq = 0; l2tp_session_set_header_len(session, tunnel->version); } else if (session->send_seq) { - l2tp_warn(session, L2TP_MSG_SEQ, - "%s: recv data has no seq numbers when required. Discarding.\n", - session->name); + pr_debug_ratelimited("%s: recv data has no seq numbers when required. Discarding.\n", + session->name); atomic_long_inc(&session->stats.rx_seq_discards); goto discard; } @@ -770,20 +773,18 @@ discard: atomic_long_inc(&session->stats.rx_errors); kfree_skb(skb); } -EXPORT_SYMBOL(l2tp_recv_common); +EXPORT_SYMBOL_GPL(l2tp_recv_common); /* Drop skbs from the session's reorder_q */ -static int l2tp_session_queue_purge(struct l2tp_session *session) +static void l2tp_session_queue_purge(struct l2tp_session *session) { struct sk_buff *skb = NULL; - BUG_ON(!session); - BUG_ON(session->magic != L2TP_SESSION_MAGIC); + while ((skb = skb_dequeue(&session->reorder_q))) { atomic_long_inc(&session->stats.rx_errors); kfree_skb(skb); } - return 0; } /* Internal UDP receive frame. Do the real work of receiving an L2TP data frame @@ -801,54 +802,39 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) u16 version; int length; - /* UDP has verifed checksum */ + /* UDP has verified checksum */ /* UDP always verifies the packet length. */ __skb_pull(skb, sizeof(struct udphdr)); /* Short packet? */ if (!pskb_may_pull(skb, L2TP_HDR_SIZE_MAX)) { - l2tp_info(tunnel, L2TP_MSG_DATA, - "%s: recv short packet (len=%d)\n", - tunnel->name, skb->len); - goto error; - } - - /* Trace packet contents, if enabled */ - if (tunnel->debug & L2TP_MSG_DATA) { - length = min(32u, skb->len); - if (!pskb_may_pull(skb, length)) - goto error; - - pr_debug("%s: recv\n", tunnel->name); - print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, skb->data, length); + pr_debug_ratelimited("%s: recv short packet (len=%d)\n", + tunnel->name, skb->len); + goto invalid; } /* Point to L2TP header */ - optr = ptr = skb->data; + optr = skb->data; + ptr = skb->data; /* Get L2TP header flags */ - hdrflags = ntohs(*(__be16 *) ptr); + hdrflags = ntohs(*(__be16 *)ptr); /* Check protocol version */ version = hdrflags & L2TP_HDR_VER_MASK; if (version != tunnel->version) { - l2tp_info(tunnel, L2TP_MSG_DATA, - "%s: recv protocol version mismatch: got %d expected %d\n", - tunnel->name, version, tunnel->version); - goto error; + pr_debug_ratelimited("%s: recv protocol version mismatch: got %d expected %d\n", + tunnel->name, version, tunnel->version); + goto invalid; } /* Get length of L2TP packet */ length = skb->len; /* If type is control packet, it is handled by userspace. */ - if (hdrflags & L2TP_HDRFLAG_T) { - l2tp_dbg(tunnel, L2TP_MSG_DATA, - "%s: recv control packet, len=%d\n", - tunnel->name, length); - goto error; - } + if (hdrflags & L2TP_HDRFLAG_T) + goto pass; /* Skip flags */ ptr += 2; @@ -859,14 +845,14 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) ptr += 2; /* Extract tunnel and session ID */ - tunnel_id = ntohs(*(__be16 *) ptr); + tunnel_id = ntohs(*(__be16 *)ptr); ptr += 2; - session_id = ntohs(*(__be16 *) ptr); + session_id = ntohs(*(__be16 *)ptr); ptr += 2; } else { ptr += 2; /* skip reserved bits */ tunnel_id = tunnel->tunnel_id; - session_id = ntohl(*(__be32 *) ptr); + session_id = ntohl(*(__be32 *)ptr); ptr += 4; } @@ -877,22 +863,26 @@ static int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb) 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", - tunnel->name, tunnel_id, session_id); - goto error; + pr_debug_ratelimited("%s: no session found (%u/%u). Passing up.\n", + tunnel->name, tunnel_id, session_id); + goto pass; } if (tunnel->version == L2TP_HDR_VER_3 && - l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) - goto error; + l2tp_v3_ensure_opt_in_linear(session, skb, &ptr, &optr)) { + l2tp_session_dec_refcount(session); + goto invalid; + } l2tp_recv_common(session, skb, ptr, optr, hdrflags, length); l2tp_session_dec_refcount(session); return 0; -error: +invalid: + atomic_long_inc(&tunnel->stats.rx_invalid); + +pass: /* Put UDP header back */ __skb_push(skb, sizeof(struct udphdr)); @@ -909,12 +899,17 @@ int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) { struct l2tp_tunnel *tunnel; + /* Note that this is called from the encap_rcv hook inside an + * RCU-protected region, but without the socket being locked. + * Hence we use rcu_dereference_sk_user_data to access the + * tunnel data structure rather the usual l2tp_sk_to_tunnel + * accessor function. + */ tunnel = rcu_dereference_sk_user_data(sk); - if (tunnel == NULL) + if (!tunnel) + goto pass_up; + if (WARN_ON(tunnel->magic != L2TP_TUNNEL_MAGIC)) goto pass_up; - - l2tp_dbg(tunnel, L2TP_MSG_DATA, "%s: received %d bytes\n", - tunnel->name, skb->len); if (l2tp_udp_recv_core(tunnel, skb)) goto pass_up; @@ -953,8 +948,7 @@ static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) *bufp++ = 0; session->ns++; session->ns &= 0xffff; - l2tp_dbg(session, L2TP_MSG_SEQ, "%s: updated ns to %u\n", - session->name, session->ns); + trace_session_seqnum_update(session); } return bufp - optr; @@ -971,13 +965,13 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) */ if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { u16 flags = L2TP_HDR_VER_3; - *((__be16 *) bufp) = htons(flags); + *((__be16 *)bufp) = htons(flags); bufp += 2; - *((__be16 *) bufp) = 0; + *((__be16 *)bufp) = 0; bufp += 2; } - *((__be32 *) bufp) = htonl(session->peer_session_id); + *((__be32 *)bufp) = htonl(session->peer_session_id); bufp += 4; if (session->cookie_len) { memcpy(bufp, &session->cookie[0], session->cookie_len); @@ -990,9 +984,7 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) l2h = 0x40000000 | session->ns; session->ns++; session->ns &= 0xffffff; - l2tp_dbg(session, L2TP_MSG_SEQ, - "%s: updated ns to %u\n", - session->name, session->ns); + trace_session_seqnum_update(session); } *((__be32 *)bufp) = htonl(l2h); @@ -1002,85 +994,53 @@ static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) return bufp - optr; } -static void l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, - struct flowi *fl, size_t data_len) +/* Queue the packet to IP for output: tunnel socket lock must be held */ +static int l2tp_xmit_queue(struct l2tp_tunnel *tunnel, struct sk_buff *skb, struct flowi *fl) { - struct l2tp_tunnel *tunnel = session->tunnel; - unsigned int len = skb->len; - int error; - - /* Debug */ - if (session->send_seq) - l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes, ns=%u\n", - session->name, data_len, session->ns - 1); - else - l2tp_dbg(session, L2TP_MSG_DATA, "%s: send %zd bytes\n", - session->name, data_len); - - if (session->debug & L2TP_MSG_DATA) { - int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; - unsigned char *datap = skb->data + uhlen; - - pr_debug("%s: xmit\n", session->name); - print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, - datap, min_t(size_t, 32, len - uhlen)); - } + int err; - /* Queue the packet to IP for output */ skb->ignore_df = 1; + skb_dst_drop(skb); #if IS_ENABLED(CONFIG_IPV6) if (l2tp_sk_is_v6(tunnel->sock)) - error = inet6_csk_xmit(tunnel->sock, skb, NULL); + err = inet6_csk_xmit(tunnel->sock, skb, NULL); else #endif - error = ip_queue_xmit(tunnel->sock, skb, fl); + err = ip_queue_xmit(tunnel->sock, skb, fl); - /* Update stats */ - if (error >= 0) { - atomic_long_inc(&tunnel->stats.tx_packets); - atomic_long_add(len, &tunnel->stats.tx_bytes); - atomic_long_inc(&session->stats.tx_packets); - atomic_long_add(len, &session->stats.tx_bytes); - } else { - atomic_long_inc(&tunnel->stats.tx_errors); - atomic_long_inc(&session->stats.tx_errors); - } + return err >= 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP; } -/* If caller requires the skb to have a ppp header, the header must be - * inserted in the skb data before calling this function. - */ -int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) +static int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, unsigned int *len) { - int data_len = skb->len; struct l2tp_tunnel *tunnel = session->tunnel; + unsigned int data_len = skb->len; struct sock *sk = tunnel->sock; - struct flowi *fl; - struct udphdr *uh; - struct inet_sock *inet; - int headroom; - int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; - int udp_len; + int headroom, uhlen, udp_len; int ret = NET_XMIT_SUCCESS; + struct inet_sock *inet; + struct udphdr *uh; /* Check that there's enough headroom in the skb to insert IP, * UDP and L2TP headers. If not enough, expand it to * make room. Adjust truesize. */ - headroom = NET_SKB_PAD + sizeof(struct iphdr) + - uhlen + hdr_len; + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(*uh) : 0; + headroom = NET_SKB_PAD + sizeof(struct iphdr) + uhlen + session->hdr_len; if (skb_cow_head(skb, headroom)) { kfree_skb(skb); return NET_XMIT_DROP; } /* Setup L2TP header */ - session->build_header(session, __skb_push(skb, hdr_len)); + if (tunnel->version == L2TP_HDR_VER_2) + l2tp_build_l2tpv2_header(session, __skb_push(skb, session->hdr_len)); + else + l2tp_build_l2tpv3_header(session, __skb_push(skb, session->hdr_len)); /* Reset skb netfilter state */ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); - IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | - IPSKB_REROUTED); + IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); nf_reset_ct(skb); bh_lock_sock(sk); @@ -1099,12 +1059,12 @@ 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)); + /* Report transmitted length before we add encap header, which keeps + * statistics consistent for both UDP and IP encap tx/rx paths. + */ + *len = skb->len; inet = inet_sk(sk); - fl = &inet->cork.fl; switch (tunnel->encap) { case L2TP_ENCAPTYPE_UDP: /* Setup UDP header */ @@ -1113,7 +1073,7 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len uh = udp_hdr(skb); uh->source = inet->inet_sport; uh->dest = inet->inet_dport; - udp_len = uhlen + hdr_len + data_len; + udp_len = uhlen + session->hdr_len + data_len; uh->len = htons(udp_len); /* Calculate UDP checksum if configured to do so */ @@ -1124,20 +1084,42 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len &sk->sk_v6_daddr, udp_len); else #endif - udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, - inet->inet_daddr, udp_len); + udp_set_csum(sk->sk_no_check_tx, skb, inet->inet_saddr, + inet->inet_daddr, udp_len); break; case L2TP_ENCAPTYPE_IP: break; } - l2tp_xmit_core(session, skb, fl, data_len); + ret = l2tp_xmit_queue(tunnel, skb, &inet->cork.fl); + out_unlock: bh_unlock_sock(sk); return ret; } + +/* If caller requires the skb to have a ppp header, the header must be + * inserted in the skb data before calling this function. + */ +int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb) +{ + unsigned int len = 0; + int ret; + + ret = l2tp_xmit_core(session, skb, &len); + if (ret == NET_XMIT_SUCCESS) { + atomic_long_inc(&session->tunnel->stats.tx_packets); + atomic_long_add(len, &session->tunnel->stats.tx_bytes); + atomic_long_inc(&session->stats.tx_packets); + atomic_long_add(len, &session->stats.tx_bytes); + } else { + atomic_long_inc(&session->tunnel->stats.tx_errors); + atomic_long_inc(&session->stats.tx_errors); + } + return ret; +} EXPORT_SYMBOL_GPL(l2tp_xmit_skb); /***************************************************************************** @@ -1150,13 +1132,11 @@ EXPORT_SYMBOL_GPL(l2tp_xmit_skb); */ static void l2tp_tunnel_destruct(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); - if (tunnel == NULL) + if (!tunnel) goto end; - l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing...\n", tunnel->name); - /* Disable udp encapsulation */ switch (tunnel->encap) { case L2TP_ENCAPTYPE_UDP: @@ -1182,46 +1162,48 @@ end: return; } +/* Remove an l2tp session from l2tp_core's hash lists. */ +static void l2tp_session_unhash(struct l2tp_session *session) +{ + struct l2tp_tunnel *tunnel = session->tunnel; + + /* Remove the session from core hashes */ + if (tunnel) { + /* Remove from the per-tunnel hash */ + spin_lock_bh(&tunnel->hlist_lock); + hlist_del_init_rcu(&session->hlist); + spin_unlock_bh(&tunnel->hlist_lock); + + /* For L2TPv3 we have a per-net hash: remove from there, too */ + 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_del_init_rcu(&session->global_hlist); + spin_unlock_bh(&pn->l2tp_session_hlist_lock); + } + + synchronize_rcu(); + } +} + /* When the tunnel is closed, all the attached sessions need to go too. */ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) { - int hash; - struct hlist_node *walk; - struct hlist_node *tmp; struct l2tp_session *session; + int hash; - BUG_ON(tunnel == NULL); - - l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: closing all sessions...\n", - tunnel->name); - - write_lock_bh(&tunnel->hlist_lock); + spin_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]) { - session = hlist_entry(walk, struct l2tp_session, hlist); - - l2tp_info(session, L2TP_MSG_CONTROL, - "%s: closing session\n", session->name); - - hlist_del_init(&session->hlist); - - if (test_and_set_bit(0, &session->dead)) - goto again; + hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { + hlist_del_init_rcu(&session->hlist); - write_unlock_bh(&tunnel->hlist_lock); - - __l2tp_session_unhash(session); - l2tp_session_queue_purge(session); - - if (session->session_close != NULL) - (*session->session_close)(session); - - l2tp_session_dec_refcount(session); - - write_lock_bh(&tunnel->hlist_lock); + spin_unlock_bh(&tunnel->hlist_lock); + l2tp_session_delete(session); + spin_lock_bh(&tunnel->hlist_lock); /* Now restart from the beginning of this hash * chain. We always remove a session from the @@ -1231,13 +1213,13 @@ again: goto again; } } - write_unlock_bh(&tunnel->hlist_lock); + spin_unlock_bh(&tunnel->hlist_lock); } /* Tunnel socket destroy hook for UDP encapsulation */ static void l2tp_udp_encap_destroy(struct sock *sk) { - struct l2tp_tunnel *tunnel = l2tp_tunnel(sk); + struct l2tp_tunnel *tunnel = l2tp_sk_to_tunnel(sk); if (tunnel) l2tp_tunnel_delete(tunnel); @@ -1287,10 +1269,10 @@ static void l2tp_tunnel_del_work(struct work_struct *work) * exit hook. */ static int l2tp_tunnel_sock_create(struct net *net, - u32 tunnel_id, - u32 peer_tunnel_id, - struct l2tp_tunnel_cfg *cfg, - struct socket **sockp) + u32 tunnel_id, + u32 peer_tunnel_id, + struct l2tp_tunnel_cfg *cfg, + struct socket **sockp) { int err = -EINVAL; struct socket *sock = NULL; @@ -1308,9 +1290,9 @@ static int l2tp_tunnel_sock_create(struct net *net, memcpy(&udp_conf.peer_ip6, cfg->peer_ip6, sizeof(udp_conf.peer_ip6)); udp_conf.use_udp6_tx_checksums = - ! cfg->udp6_zero_tx_checksums; + !cfg->udp6_zero_tx_checksums; udp_conf.use_udp6_rx_checksums = - ! cfg->udp6_zero_rx_checksums; + !cfg->udp6_zero_rx_checksums; } else #endif { @@ -1335,7 +1317,7 @@ static int l2tp_tunnel_sock_create(struct net *net, struct sockaddr_l2tpip6 ip6_addr = {0}; err = sock_create_kern(net, AF_INET6, SOCK_DGRAM, - IPPROTO_L2TP, &sock); + IPPROTO_L2TP, &sock); if (err < 0) goto out; @@ -1343,7 +1325,7 @@ static int l2tp_tunnel_sock_create(struct net *net, memcpy(&ip6_addr.l2tp_addr, cfg->local_ip6, sizeof(ip6_addr.l2tp_addr)); ip6_addr.l2tp_conn_id = tunnel_id; - err = kernel_bind(sock, (struct sockaddr *) &ip6_addr, + err = kernel_bind(sock, (struct sockaddr *)&ip6_addr, sizeof(ip6_addr)); if (err < 0) goto out; @@ -1353,7 +1335,7 @@ static int l2tp_tunnel_sock_create(struct net *net, sizeof(ip6_addr.l2tp_addr)); ip6_addr.l2tp_conn_id = peer_tunnel_id; err = kernel_connect(sock, - (struct sockaddr *) &ip6_addr, + (struct sockaddr *)&ip6_addr, sizeof(ip6_addr), 0); if (err < 0) goto out; @@ -1363,14 +1345,14 @@ static int l2tp_tunnel_sock_create(struct net *net, struct sockaddr_l2tpip ip_addr = {0}; err = sock_create_kern(net, AF_INET, SOCK_DGRAM, - IPPROTO_L2TP, &sock); + IPPROTO_L2TP, &sock); if (err < 0) goto out; ip_addr.l2tp_family = AF_INET; ip_addr.l2tp_addr = cfg->local_ip; ip_addr.l2tp_conn_id = tunnel_id; - err = kernel_bind(sock, (struct sockaddr *) &ip_addr, + err = kernel_bind(sock, (struct sockaddr *)&ip_addr, sizeof(ip_addr)); if (err < 0) goto out; @@ -1378,7 +1360,7 @@ static int l2tp_tunnel_sock_create(struct net *net, ip_addr.l2tp_family = AF_INET; ip_addr.l2tp_addr = cfg->peer_ip; ip_addr.l2tp_conn_id = peer_tunnel_id; - err = kernel_connect(sock, (struct sockaddr *) &ip_addr, + err = kernel_connect(sock, (struct sockaddr *)&ip_addr, sizeof(ip_addr), 0); if (err < 0) goto out; @@ -1391,7 +1373,7 @@ static int l2tp_tunnel_sock_create(struct net *net, out: *sockp = sock; - if ((err < 0) && sock) { + if (err < 0 && sock) { kernel_sock_shutdown(sock, SHUT_RDWR); sock_release(sock); *sockp = NULL; @@ -1402,17 +1384,18 @@ out: static struct lock_class_key l2tp_socket_class; -int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) +int l2tp_tunnel_create(int fd, int version, u32 tunnel_id, u32 peer_tunnel_id, + struct l2tp_tunnel_cfg *cfg, struct l2tp_tunnel **tunnelp) { struct l2tp_tunnel *tunnel = NULL; int err; enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; - if (cfg != NULL) + if (cfg) encap = cfg->encap; - tunnel = kzalloc(sizeof(struct l2tp_tunnel), GFP_KERNEL); - if (tunnel == NULL) { + tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL); + if (!tunnel) { err = -ENOMEM; goto err; } @@ -1420,16 +1403,12 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 tunnel->version = version; tunnel->tunnel_id = tunnel_id; tunnel->peer_tunnel_id = peer_tunnel_id; - tunnel->debug = L2TP_DEFAULT_DEBUG_FLAGS; tunnel->magic = L2TP_TUNNEL_MAGIC; sprintf(&tunnel->name[0], "tunl %u", tunnel_id); - rwlock_init(&tunnel->hlist_lock); + spin_lock_init(&tunnel->hlist_lock); tunnel->acpt_newsess = true; - if (cfg != NULL) - tunnel->debug = cfg->debug; - tunnel->encap = encap; refcount_set(&tunnel->ref_count, 1); @@ -1458,6 +1437,9 @@ static int l2tp_validate_socket(const struct sock *sk, const struct net *net, if (sk->sk_type != SOCK_DGRAM) return -EPROTONOSUPPORT; + if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6) + return -EPROTONOSUPPORT; + if ((encap == L2TP_ENCAPTYPE_UDP && sk->sk_protocol != IPPROTO_UDP) || (encap == L2TP_ENCAPTYPE_IP && sk->sk_protocol != IPPROTO_L2TP)) return -EPROTONOSUPPORT; @@ -1496,11 +1478,15 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, tunnel->l2tp_net = net; pn = l2tp_pernet(net); + sk = sock->sk; + sock_hold(sk); + tunnel->sock = sk; + spin_lock_bh(&pn->l2tp_tunnel_list_lock); list_for_each_entry(tunnel_walk, &pn->l2tp_tunnel_list, list) { if (tunnel_walk->tunnel_id == tunnel->tunnel_id) { spin_unlock_bh(&pn->l2tp_tunnel_list_lock); - + sock_put(sk); ret = -EEXIST; goto err_sock; } @@ -1508,10 +1494,6 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, list_add_rcu(&tunnel->list, &pn->l2tp_tunnel_list); spin_unlock_bh(&pn->l2tp_tunnel_list_lock); - sk = sock->sk; - sock_hold(sk); - tunnel->sock = sk; - if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { struct udp_tunnel_sock_cfg udp_cfg = { .sk_user_data = tunnel, @@ -1531,6 +1513,8 @@ int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, "l2tp_sock"); sk->sk_allocation = GFP_ATOMIC; + trace_register_tunnel(tunnel); + if (tunnel->fd >= 0) sockfd_put(sock); @@ -1551,73 +1535,25 @@ EXPORT_SYMBOL_GPL(l2tp_tunnel_register); void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel) { if (!test_and_set_bit(0, &tunnel->dead)) { + trace_delete_tunnel(tunnel); l2tp_tunnel_inc_refcount(tunnel); queue_work(l2tp_wq, &tunnel->del_work); } } EXPORT_SYMBOL_GPL(l2tp_tunnel_delete); -/* Really kill the session. - */ -void l2tp_session_free(struct l2tp_session *session) -{ - struct l2tp_tunnel *tunnel = session->tunnel; - - BUG_ON(refcount_read(&session->ref_count) != 0); - - if (tunnel) { - BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); - l2tp_tunnel_dec_refcount(tunnel); - } - - kfree(session); -} -EXPORT_SYMBOL_GPL(l2tp_session_free); - -/* Remove an l2tp session from l2tp_core's hash lists. - * Provides a tidyup interface for pseudowire code which can't just route all - * shutdown via. l2tp_session_delete and a pseudowire-specific session_close - * callback. - */ -void __l2tp_session_unhash(struct l2tp_session *session) -{ - struct l2tp_tunnel *tunnel = session->tunnel; - - /* Remove the session from core hashes */ - if (tunnel) { - /* Remove from the per-tunnel hash */ - write_lock_bh(&tunnel->hlist_lock); - hlist_del_init(&session->hlist); - write_unlock_bh(&tunnel->hlist_lock); - - /* For L2TPv3 we have a per-net hash: remove from there, too */ - 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_del_init_rcu(&session->global_hlist); - spin_unlock_bh(&pn->l2tp_session_hlist_lock); - synchronize_rcu(); - } - } -} -EXPORT_SYMBOL_GPL(__l2tp_session_unhash); - -/* This function is used by the netlink SESSION_DELETE command and by - pseudowire modules. - */ -int l2tp_session_delete(struct l2tp_session *session) +void l2tp_session_delete(struct l2tp_session *session) { if (test_and_set_bit(0, &session->dead)) - return 0; + return; - __l2tp_session_unhash(session); + trace_delete_session(session); + l2tp_session_unhash(session); l2tp_session_queue_purge(session); - if (session->session_close != NULL) + if (session->session_close) (*session->session_close)(session); l2tp_session_dec_refcount(session); - - return 0; } EXPORT_SYMBOL_GPL(l2tp_session_delete); @@ -1636,16 +1572,16 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version) if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) session->hdr_len += 4; } - } EXPORT_SYMBOL_GPL(l2tp_session_set_header_len); -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 *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; - session = kzalloc(sizeof(struct l2tp_session) + priv_size, GFP_KERNEL); - if (session != NULL) { + session = kzalloc(sizeof(*session) + priv_size, GFP_KERNEL); + if (session) { session->magic = L2TP_SESSION_MAGIC; session->tunnel = tunnel; @@ -1670,12 +1606,8 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn INIT_HLIST_NODE(&session->hlist); INIT_HLIST_NODE(&session->global_hlist); - /* Inherit debug options from tunnel */ - session->debug = tunnel->debug; - if (cfg) { session->pwtype = cfg->pw_type; - session->debug = cfg->debug; session->send_seq = cfg->send_seq; session->recv_seq = cfg->recv_seq; session->lns_mode = cfg->lns_mode; @@ -1687,11 +1619,6 @@ struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunn memcpy(&session->peer_cookie[0], &cfg->peer_cookie[0], cfg->peer_cookie_len); } - if (tunnel->version == L2TP_HDR_VER_2) - session->build_header = l2tp_build_l2tpv2_header; - else - session->build_header = l2tp_build_l2tpv3_header; - l2tp_session_set_header_len(session, tunnel->version); refcount_set(&session->ref_count, 1); |