| /***************************************************************************** |
| * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets |
| * |
| * PPPoX --- Generic PPP encapsulation socket family |
| * PPPoL2TP --- PPP over L2TP (RFC 2661) |
| * |
| * Version: 1.0.0 |
| * |
| * Authors: Martijn van Oosterhout <kleptog@svana.org> |
| * James Chapman (jchapman@katalix.com) |
| * Contributors: |
| * Michal Ostrowski <mostrows@speakeasy.net> |
| * Arnaldo Carvalho de Melo <acme@xconectiva.com.br> |
| * David S. Miller (davem@redhat.com) |
| * |
| * License: |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| */ |
| |
| /* This driver handles only L2TP data frames; control frames are handled by a |
| * userspace application. |
| * |
| * To send data in an L2TP session, userspace opens a PPPoL2TP socket and |
| * attaches it to a bound UDP socket with local tunnel_id / session_id and |
| * peer tunnel_id / session_id set. Data can then be sent or received using |
| * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket |
| * can be read or modified using ioctl() or [gs]etsockopt() calls. |
| * |
| * When a PPPoL2TP socket is connected with local and peer session_id values |
| * zero, the socket is treated as a special tunnel management socket. |
| * |
| * Here's example userspace code to create a socket for sending/receiving data |
| * over an L2TP session:- |
| * |
| * struct sockaddr_pppol2tp sax; |
| * int fd; |
| * int session_fd; |
| * |
| * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); |
| * |
| * sax.sa_family = AF_PPPOX; |
| * sax.sa_protocol = PX_PROTO_OL2TP; |
| * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket |
| * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; |
| * sax.pppol2tp.addr.sin_port = addr->sin_port; |
| * sax.pppol2tp.addr.sin_family = AF_INET; |
| * sax.pppol2tp.s_tunnel = tunnel_id; |
| * sax.pppol2tp.s_session = session_id; |
| * sax.pppol2tp.d_tunnel = peer_tunnel_id; |
| * sax.pppol2tp.d_session = peer_session_id; |
| * |
| * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); |
| * |
| * A pppd plugin that allows PPP traffic to be carried over L2TP using |
| * this driver is available from the OpenL2TP project at |
| * http://openl2tp.sourceforge.net. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/string.h> |
| #include <linux/list.h> |
| #include <asm/uaccess.h> |
| |
| #include <linux/kernel.h> |
| #include <linux/spinlock.h> |
| #include <linux/kthread.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/errno.h> |
| #include <linux/jiffies.h> |
| |
| #include <linux/netdevice.h> |
| #include <linux/net.h> |
| #include <linux/inetdevice.h> |
| #include <linux/skbuff.h> |
| #include <linux/init.h> |
| #include <linux/ip.h> |
| #include <linux/udp.h> |
| #include <linux/if_pppox.h> |
| #include <linux/if_pppol2tp.h> |
| #include <net/sock.h> |
| #include <linux/ppp_channel.h> |
| #include <linux/ppp_defs.h> |
| #include <linux/if_ppp.h> |
| #include <linux/file.h> |
| #include <linux/hash.h> |
| #include <linux/sort.h> |
| #include <linux/proc_fs.h> |
| #include <net/net_namespace.h> |
| #include <net/dst.h> |
| #include <net/ip.h> |
| #include <net/udp.h> |
| #include <net/xfrm.h> |
| |
| #include <asm/byteorder.h> |
| #include <asm/atomic.h> |
| |
| |
| #define PPPOL2TP_DRV_VERSION "V1.0" |
| |
| /* L2TP header constants */ |
| #define L2TP_HDRFLAG_T 0x8000 |
| #define L2TP_HDRFLAG_L 0x4000 |
| #define L2TP_HDRFLAG_S 0x0800 |
| #define L2TP_HDRFLAG_O 0x0200 |
| #define L2TP_HDRFLAG_P 0x0100 |
| |
| #define L2TP_HDR_VER_MASK 0x000F |
| #define L2TP_HDR_VER 0x0002 |
| |
| /* Space for UDP, L2TP and PPP headers */ |
| #define PPPOL2TP_HEADER_OVERHEAD 40 |
| |
| /* Just some random numbers */ |
| #define L2TP_TUNNEL_MAGIC 0x42114DDA |
| #define L2TP_SESSION_MAGIC 0x0C04EB7D |
| |
| #define PPPOL2TP_HASH_BITS 4 |
| #define PPPOL2TP_HASH_SIZE (1 << PPPOL2TP_HASH_BITS) |
| |
| /* Default trace flags */ |
| #define PPPOL2TP_DEFAULT_DEBUG_FLAGS 0 |
| |
| #define PRINTK(_mask, _type, _lvl, _fmt, args...) \ |
| do { \ |
| if ((_mask) & (_type)) \ |
| printk(_lvl "PPPOL2TP: " _fmt, ##args); \ |
| } while(0) |
| |
| /* Number of bytes to build transmit L2TP headers. |
| * Unfortunately the size is different depending on whether sequence numbers |
| * are enabled. |
| */ |
| #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 |
| #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 |
| |
| struct pppol2tp_tunnel; |
| |
| /* Describes a session. It is the sk_user_data field in the PPPoL2TP |
| * socket. Contains information to determine incoming packets and transmit |
| * outgoing ones. |
| */ |
| struct pppol2tp_session |
| { |
| int magic; /* should be |
| * L2TP_SESSION_MAGIC */ |
| int owner; /* pid that opened the socket */ |
| |
| struct sock *sock; /* Pointer to the session |
| * PPPoX socket */ |
| struct sock *tunnel_sock; /* Pointer to the tunnel UDP |
| * socket */ |
| |
| struct pppol2tp_addr tunnel_addr; /* Description of tunnel */ |
| |
| struct pppol2tp_tunnel *tunnel; /* back pointer to tunnel |
| * context */ |
| |
| char name[20]; /* "sess xxxxx/yyyyy", where |
| * x=tunnel_id, y=session_id */ |
| int mtu; |
| int mru; |
| int flags; /* accessed by PPPIOCGFLAGS. |
| * Unused. */ |
| unsigned recv_seq:1; /* expect receive packets with |
| * sequence numbers? */ |
| unsigned send_seq:1; /* send packets with sequence |
| * numbers? */ |
| unsigned lns_mode:1; /* behave as LNS? LAC enables |
| * sequence numbers under |
| * control of LNS. */ |
| int debug; /* bitmask of debug message |
| * categories */ |
| int reorder_timeout; /* configured reorder timeout |
| * (in jiffies) */ |
| u16 nr; /* session NR state (receive) */ |
| u16 ns; /* session NR state (send) */ |
| struct sk_buff_head reorder_q; /* receive reorder queue */ |
| struct pppol2tp_ioc_stats stats; |
| struct hlist_node hlist; /* Hash list node */ |
| }; |
| |
| /* The sk_user_data field of the tunnel's UDP socket. It contains info to track |
| * all the associated sessions so incoming packets can be sorted out |
| */ |
| struct pppol2tp_tunnel |
| { |
| int magic; /* Should be L2TP_TUNNEL_MAGIC */ |
| rwlock_t hlist_lock; /* protect session_hlist */ |
| struct hlist_head session_hlist[PPPOL2TP_HASH_SIZE]; |
| /* hashed list of sessions, |
| * hashed by id */ |
| int debug; /* bitmask of debug message |
| * categories */ |
| char name[12]; /* "tunl xxxxx" */ |
| struct pppol2tp_ioc_stats stats; |
| |
| void (*old_sk_destruct)(struct sock *); |
| |
| struct sock *sock; /* Parent socket */ |
| struct list_head list; /* Keep a list of all open |
| * prepared sockets */ |
| |
| atomic_t ref_count; |
| }; |
| |
| /* Private data stored for received packets in the skb. |
| */ |
| struct pppol2tp_skb_cb { |
| u16 ns; |
| u16 nr; |
| u16 has_seq; |
| u16 length; |
| unsigned long expires; |
| }; |
| |
| #define PPPOL2TP_SKB_CB(skb) ((struct pppol2tp_skb_cb *) &skb->cb[sizeof(struct inet_skb_parm)]) |
| |
| static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); |
| static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel); |
| |
| static atomic_t pppol2tp_tunnel_count; |
| static atomic_t pppol2tp_session_count; |
| static struct ppp_channel_ops pppol2tp_chan_ops = { pppol2tp_xmit , NULL }; |
| static struct proto_ops pppol2tp_ops; |
| static LIST_HEAD(pppol2tp_tunnel_list); |
| static DEFINE_RWLOCK(pppol2tp_tunnel_list_lock); |
| |
| /* Helpers to obtain tunnel/session contexts from sockets. |
| */ |
| static inline struct pppol2tp_session *pppol2tp_sock_to_session(struct sock *sk) |
| { |
| struct pppol2tp_session *session; |
| |
| if (sk == NULL) |
| return NULL; |
| |
| sock_hold(sk); |
| session = (struct pppol2tp_session *)(sk->sk_user_data); |
| if (session == NULL) { |
| sock_put(sk); |
| goto out; |
| } |
| |
| BUG_ON(session->magic != L2TP_SESSION_MAGIC); |
| out: |
| return session; |
| } |
| |
| static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk) |
| { |
| struct pppol2tp_tunnel *tunnel; |
| |
| if (sk == NULL) |
| return NULL; |
| |
| sock_hold(sk); |
| tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data); |
| if (tunnel == NULL) { |
| sock_put(sk); |
| goto out; |
| } |
| |
| BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| out: |
| return tunnel; |
| } |
| |
| /* Tunnel reference counts. Incremented per session that is added to |
| * the tunnel. |
| */ |
| static inline void pppol2tp_tunnel_inc_refcount(struct pppol2tp_tunnel *tunnel) |
| { |
| atomic_inc(&tunnel->ref_count); |
| } |
| |
| static inline void pppol2tp_tunnel_dec_refcount(struct pppol2tp_tunnel *tunnel) |
| { |
| if (atomic_dec_and_test(&tunnel->ref_count)) |
| pppol2tp_tunnel_free(tunnel); |
| } |
| |
| /* Session hash list. |
| * The session_id SHOULD be random according to RFC2661, but several |
| * L2TP implementations (Cisco and Microsoft) use incrementing |
| * session_ids. So we do a real hash on the session_id, rather than a |
| * simple bitmask. |
| */ |
| static inline struct hlist_head * |
| pppol2tp_session_id_hash(struct pppol2tp_tunnel *tunnel, u16 session_id) |
| { |
| unsigned long hash_val = (unsigned long) session_id; |
| return &tunnel->session_hlist[hash_long(hash_val, PPPOL2TP_HASH_BITS)]; |
| } |
| |
| /* Lookup a session by id |
| */ |
| static struct pppol2tp_session * |
| pppol2tp_session_find(struct pppol2tp_tunnel *tunnel, u16 session_id) |
| { |
| struct hlist_head *session_list = |
| pppol2tp_session_id_hash(tunnel, session_id); |
| struct pppol2tp_session *session; |
| struct hlist_node *walk; |
| |
| read_lock_bh(&tunnel->hlist_lock); |
| hlist_for_each_entry(session, walk, session_list, hlist) { |
| if (session->tunnel_addr.s_session == session_id) { |
| read_unlock_bh(&tunnel->hlist_lock); |
| return session; |
| } |
| } |
| read_unlock_bh(&tunnel->hlist_lock); |
| |
| return NULL; |
| } |
| |
| /* Lookup a tunnel by id |
| */ |
| static struct pppol2tp_tunnel *pppol2tp_tunnel_find(u16 tunnel_id) |
| { |
| struct pppol2tp_tunnel *tunnel = NULL; |
| |
| read_lock_bh(&pppol2tp_tunnel_list_lock); |
| list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) { |
| if (tunnel->stats.tunnel_id == tunnel_id) { |
| read_unlock_bh(&pppol2tp_tunnel_list_lock); |
| return tunnel; |
| } |
| } |
| read_unlock_bh(&pppol2tp_tunnel_list_lock); |
| |
| return NULL; |
| } |
| |
| /***************************************************************************** |
| * Receive data handling |
| *****************************************************************************/ |
| |
| /* Queue a skb in order. We come here only if the skb has an L2TP sequence |
| * number. |
| */ |
| static void pppol2tp_recv_queue_skb(struct pppol2tp_session *session, struct sk_buff *skb) |
| { |
| struct sk_buff *skbp; |
| struct sk_buff *tmp; |
| u16 ns = PPPOL2TP_SKB_CB(skb)->ns; |
| |
| spin_lock_bh(&session->reorder_q.lock); |
| skb_queue_walk_safe(&session->reorder_q, skbp, tmp) { |
| if (PPPOL2TP_SKB_CB(skbp)->ns > ns) { |
| __skb_queue_before(&session->reorder_q, skbp, skb); |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: pkt %hu, inserted before %hu, reorder_q len=%d\n", |
| session->name, ns, PPPOL2TP_SKB_CB(skbp)->ns, |
| skb_queue_len(&session->reorder_q)); |
| session->stats.rx_oos_packets++; |
| goto out; |
| } |
| } |
| |
| __skb_queue_tail(&session->reorder_q, skb); |
| |
| out: |
| spin_unlock_bh(&session->reorder_q.lock); |
| } |
| |
| /* Dequeue a single skb. |
| */ |
| static void pppol2tp_recv_dequeue_skb(struct pppol2tp_session *session, struct sk_buff *skb) |
| { |
| struct pppol2tp_tunnel *tunnel = session->tunnel; |
| int length = PPPOL2TP_SKB_CB(skb)->length; |
| struct sock *session_sock = NULL; |
| |
| /* We're about to requeue the skb, so return resources |
| * to its current owner (a socket receive buffer). |
| */ |
| skb_orphan(skb); |
| |
| tunnel->stats.rx_packets++; |
| tunnel->stats.rx_bytes += length; |
| session->stats.rx_packets++; |
| session->stats.rx_bytes += length; |
| |
| if (PPPOL2TP_SKB_CB(skb)->has_seq) { |
| /* Bump our Nr */ |
| session->nr++; |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: updated nr to %hu\n", session->name, session->nr); |
| } |
| |
| /* If the socket is bound, send it in to PPP's input queue. Otherwise |
| * queue it on the session socket. |
| */ |
| session_sock = session->sock; |
| if (session_sock->sk_state & PPPOX_BOUND) { |
| struct pppox_sock *po; |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: recv %d byte data frame, passing to ppp\n", |
| session->name, length); |
| |
| /* We need to forget all info related to the L2TP packet |
| * gathered in the skb as we are going to reuse the same |
| * skb for the inner packet. |
| * Namely we need to: |
| * - reset xfrm (IPSec) information as it applies to |
| * the outer L2TP packet and not to the inner one |
| * - release the dst to force a route lookup on the inner |
| * IP packet since skb->dst currently points to the dst |
| * of the UDP tunnel |
| * - reset netfilter information as it doesn't apply |
| * to the inner packet either |
| */ |
| secpath_reset(skb); |
| dst_release(skb->dst); |
| skb->dst = NULL; |
| nf_reset(skb); |
| |
| po = pppox_sk(session_sock); |
| ppp_input(&po->chan, skb); |
| } else { |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_INFO, |
| "%s: socket not bound\n", session->name); |
| |
| /* Not bound. Nothing we can do, so discard. */ |
| session->stats.rx_errors++; |
| kfree_skb(skb); |
| } |
| |
| sock_put(session->sock); |
| } |
| |
| /* Dequeue skbs from the session's reorder_q, subject to packet order. |
| * Skbs that have been in the queue for too long are simply discarded. |
| */ |
| static void pppol2tp_recv_dequeue(struct pppol2tp_session *session) |
| { |
| struct sk_buff *skb; |
| struct sk_buff *tmp; |
| |
| /* If the pkt at the head of the queue has the nr that we |
| * expect to send up next, dequeue it and any other |
| * in-sequence packets behind it. |
| */ |
| spin_lock_bh(&session->reorder_q.lock); |
| skb_queue_walk_safe(&session->reorder_q, skb, tmp) { |
| if (time_after(jiffies, PPPOL2TP_SKB_CB(skb)->expires)) { |
| session->stats.rx_seq_discards++; |
| session->stats.rx_errors++; |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: oos pkt %hu len %d discarded (too old), " |
| "waiting for %hu, reorder_q_len=%d\n", |
| session->name, PPPOL2TP_SKB_CB(skb)->ns, |
| PPPOL2TP_SKB_CB(skb)->length, session->nr, |
| skb_queue_len(&session->reorder_q)); |
| __skb_unlink(skb, &session->reorder_q); |
| kfree_skb(skb); |
| sock_put(session->sock); |
| continue; |
| } |
| |
| if (PPPOL2TP_SKB_CB(skb)->has_seq) { |
| if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) { |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: holding oos pkt %hu len %d, " |
| "waiting for %hu, reorder_q_len=%d\n", |
| session->name, PPPOL2TP_SKB_CB(skb)->ns, |
| PPPOL2TP_SKB_CB(skb)->length, session->nr, |
| skb_queue_len(&session->reorder_q)); |
| goto out; |
| } |
| } |
| __skb_unlink(skb, &session->reorder_q); |
| |
| /* Process the skb. We release the queue lock while we |
| * do so to let other contexts process the queue. |
| */ |
| spin_unlock_bh(&session->reorder_q.lock); |
| pppol2tp_recv_dequeue_skb(session, skb); |
| spin_lock_bh(&session->reorder_q.lock); |
| } |
| |
| out: |
| spin_unlock_bh(&session->reorder_q.lock); |
| } |
| |
| /* Internal receive frame. Do the real work of receiving an L2TP data frame |
| * here. The skb is not on a list when we get here. |
| * Returns 0 if the packet was a data packet and was successfully passed on. |
| * Returns 1 if the packet was not a good data packet and could not be |
| * forwarded. All such packets are passed up to userspace to deal with. |
| */ |
| static int pppol2tp_recv_core(struct sock *sock, struct sk_buff *skb) |
| { |
| struct pppol2tp_session *session = NULL; |
| struct pppol2tp_tunnel *tunnel; |
| unsigned char *ptr, *optr; |
| u16 hdrflags; |
| u16 tunnel_id, session_id; |
| int length; |
| int offset; |
| |
| tunnel = pppol2tp_sock_to_tunnel(sock); |
| if (tunnel == NULL) |
| goto no_tunnel; |
| |
| /* UDP always verifies the packet length. */ |
| __skb_pull(skb, sizeof(struct udphdr)); |
| |
| /* Short packet? */ |
| if (!pskb_may_pull(skb, 12)) { |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO, |
| "%s: recv short packet (len=%d)\n", tunnel->name, skb->len); |
| goto error; |
| } |
| |
| /* Point to L2TP header */ |
| optr = ptr = skb->data; |
| |
| /* Get L2TP header flags */ |
| hdrflags = ntohs(*(__be16*)ptr); |
| |
| /* Trace packet contents, if enabled */ |
| if (tunnel->debug & PPPOL2TP_MSG_DATA) { |
| length = min(16u, skb->len); |
| if (!pskb_may_pull(skb, length)) |
| goto error; |
| |
| printk(KERN_DEBUG "%s: recv: ", tunnel->name); |
| |
| offset = 0; |
| do { |
| printk(" %02X", ptr[offset]); |
| } while (++offset < length); |
| |
| printk("\n"); |
| } |
| |
| /* Get length of L2TP packet */ |
| length = skb->len; |
| |
| /* If type is control packet, it is handled by userspace. */ |
| if (hdrflags & L2TP_HDRFLAG_T) { |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: recv control packet, len=%d\n", tunnel->name, length); |
| goto error; |
| } |
| |
| /* Skip flags */ |
| ptr += 2; |
| |
| /* If length is present, skip it */ |
| if (hdrflags & L2TP_HDRFLAG_L) |
| ptr += 2; |
| |
| /* Extract tunnel and session ID */ |
| tunnel_id = ntohs(*(__be16 *) ptr); |
| ptr += 2; |
| session_id = ntohs(*(__be16 *) ptr); |
| ptr += 2; |
| |
| /* Find the session context */ |
| session = pppol2tp_session_find(tunnel, session_id); |
| if (!session) { |
| /* Not found? Pass to userspace to deal with */ |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO, |
| "%s: no socket found (%hu/%hu). Passing up.\n", |
| tunnel->name, tunnel_id, session_id); |
| goto error; |
| } |
| sock_hold(session->sock); |
| |
| /* The ref count on the socket was increased by the above call since |
| * we now hold a pointer to the session. Take care to do sock_put() |
| * when exiting this function from now on... |
| */ |
| |
| /* Handle the optional sequence numbers. If we are the LAC, |
| * enable/disable sequence numbers under the control of the LNS. If |
| * no sequence numbers present but we were expecting them, discard |
| * frame. |
| */ |
| if (hdrflags & L2TP_HDRFLAG_S) { |
| u16 ns, nr; |
| ns = ntohs(*(__be16 *) ptr); |
| ptr += 2; |
| nr = ntohs(*(__be16 *) ptr); |
| ptr += 2; |
| |
| /* Received a packet with sequence numbers. If we're the LNS, |
| * check if we sre sending sequence numbers and if not, |
| * configure it so. |
| */ |
| if ((!session->lns_mode) && (!session->send_seq)) { |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO, |
| "%s: requested to enable seq numbers by LNS\n", |
| session->name); |
| session->send_seq = -1; |
| } |
| |
| /* Store L2TP info in the skb */ |
| PPPOL2TP_SKB_CB(skb)->ns = ns; |
| PPPOL2TP_SKB_CB(skb)->nr = nr; |
| PPPOL2TP_SKB_CB(skb)->has_seq = 1; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: recv data ns=%hu, nr=%hu, session nr=%hu\n", |
| session->name, ns, nr, session->nr); |
| } else { |
| /* No sequence numbers. |
| * If user has configured mandatory sequence numbers, discard. |
| */ |
| if (session->recv_seq) { |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING, |
| "%s: recv data has no seq numbers when required. " |
| "Discarding\n", session->name); |
| session->stats.rx_seq_discards++; |
| goto discard; |
| } |
| |
| /* If we're the LAC and we're sending sequence numbers, the |
| * LNS has requested that we no longer send sequence numbers. |
| * 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)) { |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_INFO, |
| "%s: requested to disable seq numbers by LNS\n", |
| session->name); |
| session->send_seq = 0; |
| } else if (session->send_seq) { |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_WARNING, |
| "%s: recv data has no seq numbers when required. " |
| "Discarding\n", session->name); |
| session->stats.rx_seq_discards++; |
| goto discard; |
| } |
| |
| /* Store L2TP info in the skb */ |
| PPPOL2TP_SKB_CB(skb)->has_seq = 0; |
| } |
| |
| /* If offset bit set, skip it. */ |
| if (hdrflags & L2TP_HDRFLAG_O) { |
| offset = ntohs(*(__be16 *)ptr); |
| ptr += 2 + offset; |
| } |
| |
| offset = ptr - optr; |
| if (!pskb_may_pull(skb, offset)) |
| goto discard; |
| |
| __skb_pull(skb, offset); |
| |
| /* Skip PPP header, if present. In testing, Microsoft L2TP clients |
| * don't send the PPP header (PPP header compression enabled), but |
| * other clients can include the header. So we cope with both cases |
| * here. The PPP header is always FF03 when using L2TP. |
| * |
| * Note that skb->data[] isn't dereferenced from a u16 ptr here since |
| * the field may be unaligned. |
| */ |
| if (!pskb_may_pull(skb, 2)) |
| goto discard; |
| |
| if ((skb->data[0] == 0xff) && (skb->data[1] == 0x03)) |
| skb_pull(skb, 2); |
| |
| /* Prepare skb for adding to the session's reorder_q. Hold |
| * packets for max reorder_timeout or 1 second if not |
| * reordering. |
| */ |
| PPPOL2TP_SKB_CB(skb)->length = length; |
| PPPOL2TP_SKB_CB(skb)->expires = jiffies + |
| (session->reorder_timeout ? session->reorder_timeout : HZ); |
| |
| /* Add packet to the session's receive queue. Reordering is done here, if |
| * enabled. Saved L2TP protocol info is stored in skb->sb[]. |
| */ |
| if (PPPOL2TP_SKB_CB(skb)->has_seq) { |
| if (session->reorder_timeout != 0) { |
| /* Packet reordering enabled. Add skb to session's |
| * reorder queue, in order of ns. |
| */ |
| pppol2tp_recv_queue_skb(session, skb); |
| } else { |
| /* Packet reordering disabled. Discard out-of-sequence |
| * packets |
| */ |
| if (PPPOL2TP_SKB_CB(skb)->ns != session->nr) { |
| session->stats.rx_seq_discards++; |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: oos pkt %hu len %d discarded, " |
| "waiting for %hu, reorder_q_len=%d\n", |
| session->name, PPPOL2TP_SKB_CB(skb)->ns, |
| PPPOL2TP_SKB_CB(skb)->length, session->nr, |
| skb_queue_len(&session->reorder_q)); |
| goto discard; |
| } |
| skb_queue_tail(&session->reorder_q, skb); |
| } |
| } else { |
| /* No sequence numbers. Add the skb to the tail of the |
| * reorder queue. This ensures that it will be |
| * delivered after all previous sequenced skbs. |
| */ |
| skb_queue_tail(&session->reorder_q, skb); |
| } |
| |
| /* Try to dequeue as many skbs from reorder_q as we can. */ |
| pppol2tp_recv_dequeue(session); |
| |
| return 0; |
| |
| discard: |
| session->stats.rx_errors++; |
| kfree_skb(skb); |
| sock_put(session->sock); |
| sock_put(sock); |
| |
| return 0; |
| |
| error: |
| /* Put UDP header back */ |
| __skb_push(skb, sizeof(struct udphdr)); |
| sock_put(sock); |
| |
| no_tunnel: |
| return 1; |
| } |
| |
| /* UDP encapsulation receive handler. See net/ipv4/udp.c. |
| * Return codes: |
| * 0 : success. |
| * <0: error |
| * >0: skb should be passed up to userspace as UDP. |
| */ |
| static int pppol2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb) |
| { |
| struct pppol2tp_tunnel *tunnel; |
| |
| tunnel = pppol2tp_sock_to_tunnel(sk); |
| if (tunnel == NULL) |
| goto pass_up; |
| |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: received %d bytes\n", tunnel->name, skb->len); |
| |
| if (pppol2tp_recv_core(sk, skb)) |
| goto pass_up_put; |
| |
| sock_put(sk); |
| return 0; |
| |
| pass_up_put: |
| sock_put(sk); |
| pass_up: |
| return 1; |
| } |
| |
| /* Receive message. This is the recvmsg for the PPPoL2TP socket. |
| */ |
| static int pppol2tp_recvmsg(struct kiocb *iocb, struct socket *sock, |
| struct msghdr *msg, size_t len, |
| int flags) |
| { |
| int err; |
| struct sk_buff *skb; |
| struct sock *sk = sock->sk; |
| |
| err = -EIO; |
| if (sk->sk_state & PPPOX_BOUND) |
| goto end; |
| |
| msg->msg_namelen = 0; |
| |
| err = 0; |
| skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, |
| flags & MSG_DONTWAIT, &err); |
| if (!skb) |
| goto end; |
| |
| if (len > skb->len) |
| len = skb->len; |
| else if (len < skb->len) |
| msg->msg_flags |= MSG_TRUNC; |
| |
| err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len); |
| if (likely(err == 0)) |
| err = len; |
| |
| kfree_skb(skb); |
| end: |
| return err; |
| } |
| |
| /************************************************************************ |
| * Transmit handling |
| ***********************************************************************/ |
| |
| /* Tell how big L2TP headers are for a particular session. This |
| * depends on whether sequence numbers are being used. |
| */ |
| static inline int pppol2tp_l2tp_header_len(struct pppol2tp_session *session) |
| { |
| if (session->send_seq) |
| return PPPOL2TP_L2TP_HDR_SIZE_SEQ; |
| |
| return PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; |
| } |
| |
| /* Build an L2TP header for the session into the buffer provided. |
| */ |
| static void pppol2tp_build_l2tp_header(struct pppol2tp_session *session, |
| void *buf) |
| { |
| __be16 *bufp = buf; |
| u16 flags = L2TP_HDR_VER; |
| |
| if (session->send_seq) |
| flags |= L2TP_HDRFLAG_S; |
| |
| /* Setup L2TP header. |
| * FIXME: Can this ever be unaligned? Is direct dereferencing of |
| * 16-bit header fields safe here for all architectures? |
| */ |
| *bufp++ = htons(flags); |
| *bufp++ = htons(session->tunnel_addr.d_tunnel); |
| *bufp++ = htons(session->tunnel_addr.d_session); |
| if (session->send_seq) { |
| *bufp++ = htons(session->ns); |
| *bufp++ = 0; |
| session->ns++; |
| PRINTK(session->debug, PPPOL2TP_MSG_SEQ, KERN_DEBUG, |
| "%s: updated ns to %hu\n", session->name, session->ns); |
| } |
| } |
| |
| /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here |
| * when a user application does a sendmsg() on the session socket. L2TP and |
| * PPP headers must be inserted into the user's data. |
| */ |
| static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, |
| size_t total_len) |
| { |
| static const unsigned char ppph[2] = { 0xff, 0x03 }; |
| struct sock *sk = sock->sk; |
| struct inet_sock *inet; |
| __wsum csum = 0; |
| struct sk_buff *skb; |
| int error; |
| int hdr_len; |
| struct pppol2tp_session *session; |
| struct pppol2tp_tunnel *tunnel; |
| struct udphdr *uh; |
| unsigned int len; |
| |
| error = -ENOTCONN; |
| if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) |
| goto error; |
| |
| /* Get session and tunnel contexts */ |
| error = -EBADF; |
| session = pppol2tp_sock_to_session(sk); |
| if (session == NULL) |
| goto error; |
| |
| tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); |
| if (tunnel == NULL) |
| goto error_put_sess; |
| |
| /* What header length is configured for this session? */ |
| hdr_len = pppol2tp_l2tp_header_len(session); |
| |
| /* Allocate a socket buffer */ |
| error = -ENOMEM; |
| skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + |
| sizeof(struct udphdr) + hdr_len + |
| sizeof(ppph) + total_len, |
| 0, GFP_KERNEL); |
| if (!skb) |
| goto error_put_sess_tun; |
| |
| /* Reserve space for headers. */ |
| skb_reserve(skb, NET_SKB_PAD); |
| skb_reset_network_header(skb); |
| skb_reserve(skb, sizeof(struct iphdr)); |
| skb_reset_transport_header(skb); |
| |
| /* Build UDP header */ |
| inet = inet_sk(session->tunnel_sock); |
| uh = (struct udphdr *) skb->data; |
| uh->source = inet->sport; |
| uh->dest = inet->dport; |
| uh->len = htons(hdr_len + sizeof(ppph) + total_len); |
| uh->check = 0; |
| skb_put(skb, sizeof(struct udphdr)); |
| |
| /* Build L2TP header */ |
| pppol2tp_build_l2tp_header(session, skb->data); |
| skb_put(skb, hdr_len); |
| |
| /* Add PPP header */ |
| skb->data[0] = ppph[0]; |
| skb->data[1] = ppph[1]; |
| skb_put(skb, 2); |
| |
| /* Copy user data into skb */ |
| error = memcpy_fromiovec(skb->data, m->msg_iov, total_len); |
| if (error < 0) { |
| kfree_skb(skb); |
| goto error_put_sess_tun; |
| } |
| skb_put(skb, total_len); |
| |
| /* Calculate UDP checksum if configured to do so */ |
| if (session->tunnel_sock->sk_no_check != UDP_CSUM_NOXMIT) |
| csum = udp_csum_outgoing(sk, skb); |
| |
| /* Debug */ |
| if (session->send_seq) |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: send %Zd bytes, ns=%hu\n", session->name, |
| total_len, session->ns - 1); |
| else |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: send %Zd bytes\n", session->name, total_len); |
| |
| if (session->debug & PPPOL2TP_MSG_DATA) { |
| int i; |
| unsigned char *datap = skb->data; |
| |
| printk(KERN_DEBUG "%s: xmit:", session->name); |
| for (i = 0; i < total_len; i++) { |
| printk(" %02X", *datap++); |
| if (i == 15) { |
| printk(" ..."); |
| break; |
| } |
| } |
| printk("\n"); |
| } |
| |
| /* Queue the packet to IP for output */ |
| len = skb->len; |
| error = ip_queue_xmit(skb, 1); |
| |
| /* Update stats */ |
| if (error >= 0) { |
| tunnel->stats.tx_packets++; |
| tunnel->stats.tx_bytes += len; |
| session->stats.tx_packets++; |
| session->stats.tx_bytes += len; |
| } else { |
| tunnel->stats.tx_errors++; |
| session->stats.tx_errors++; |
| } |
| |
| return error; |
| |
| error_put_sess_tun: |
| sock_put(session->tunnel_sock); |
| error_put_sess: |
| sock_put(sk); |
| error: |
| return error; |
| } |
| |
| /* Automatically called when the skb is freed. |
| */ |
| static void pppol2tp_sock_wfree(struct sk_buff *skb) |
| { |
| sock_put(skb->sk); |
| } |
| |
| /* For data skbs that we transmit, we associate with the tunnel socket |
| * but don't do accounting. |
| */ |
| static inline void pppol2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) |
| { |
| sock_hold(sk); |
| skb->sk = sk; |
| skb->destructor = pppol2tp_sock_wfree; |
| } |
| |
| /* Transmit function called by generic PPP driver. Sends PPP frame |
| * over PPPoL2TP socket. |
| * |
| * This is almost the same as pppol2tp_sendmsg(), but rather than |
| * being called with a msghdr from userspace, it is called with a skb |
| * from the kernel. |
| * |
| * The supplied skb from ppp doesn't have enough headroom for the |
| * insertion of L2TP, UDP and IP headers so we need to allocate more |
| * headroom in the skb. This will create a cloned skb. But we must be |
| * careful in the error case because the caller will expect to free |
| * the skb it supplied, not our cloned skb. So we take care to always |
| * leave the original skb unfreed if we return an 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; |
| int hdr_len; |
| struct pppol2tp_session *session; |
| struct pppol2tp_tunnel *tunnel; |
| int rc; |
| int headroom; |
| int data_len = skb->len; |
| struct inet_sock *inet; |
| __wsum csum = 0; |
| struct udphdr *uh; |
| unsigned int len; |
| int old_headroom; |
| int new_headroom; |
| |
| if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) |
| goto abort; |
| |
| /* Get session and tunnel contexts from the socket */ |
| session = pppol2tp_sock_to_session(sk); |
| if (session == NULL) |
| goto abort; |
| |
| sk_tun = session->tunnel_sock; |
| if (sk_tun == NULL) |
| goto abort_put_sess; |
| tunnel = pppol2tp_sock_to_tunnel(sk_tun); |
| if (tunnel == NULL) |
| goto abort_put_sess; |
| |
| /* What header length is configured for this session? */ |
| hdr_len = pppol2tp_l2tp_header_len(session); |
| |
| /* Check that there's enough headroom in the skb to insert IP, |
| * UDP and L2TP and PPP headers. If not enough, expand it to |
| * make room. Adjust truesize. |
| */ |
| headroom = NET_SKB_PAD + sizeof(struct iphdr) + |
| sizeof(struct udphdr) + hdr_len + sizeof(ppph); |
| old_headroom = skb_headroom(skb); |
| if (skb_cow_head(skb, headroom)) |
| goto abort_put_sess_tun; |
| |
| new_headroom = skb_headroom(skb); |
| skb_orphan(skb); |
| skb->truesize += new_headroom - old_headroom; |
| |
| /* Setup PPP header */ |
| __skb_push(skb, sizeof(ppph)); |
| skb->data[0] = ppph[0]; |
| skb->data[1] = ppph[1]; |
| |
| /* Setup L2TP header */ |
| pppol2tp_build_l2tp_header(session, __skb_push(skb, hdr_len)); |
| |
| /* Setup UDP header */ |
| inet = inet_sk(sk_tun); |
| __skb_push(skb, sizeof(*uh)); |
| skb_reset_transport_header(skb); |
| uh = udp_hdr(skb); |
| uh->source = inet->sport; |
| uh->dest = inet->dport; |
| uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len); |
| uh->check = 0; |
| |
| /* *BROKEN* Calculate UDP checksum if configured to do so */ |
| if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT) |
| csum = udp_csum_outgoing(sk_tun, skb); |
| |
| /* Debug */ |
| if (session->send_seq) |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: send %d bytes, ns=%hu\n", session->name, |
| data_len, session->ns - 1); |
| else |
| PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG, |
| "%s: send %d bytes\n", session->name, data_len); |
| |
| if (session->debug & PPPOL2TP_MSG_DATA) { |
| int i; |
| unsigned char *datap = skb->data; |
| |
| printk(KERN_DEBUG "%s: xmit:", session->name); |
| for (i = 0; i < data_len; i++) { |
| printk(" %02X", *datap++); |
| if (i == 31) { |
| printk(" ..."); |
| break; |
| } |
| } |
| printk("\n"); |
| } |
| |
| memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | |
| IPSKB_REROUTED); |
| nf_reset(skb); |
| |
| /* Get routing info from the tunnel socket */ |
| dst_release(skb->dst); |
| skb->dst = dst_clone(__sk_dst_get(sk_tun)); |
| pppol2tp_skb_set_owner_w(skb, sk_tun); |
| |
| /* Queue the packet to IP for output */ |
| len = skb->len; |
| rc = ip_queue_xmit(skb, 1); |
| |
| /* Update stats */ |
| if (rc >= 0) { |
| tunnel->stats.tx_packets++; |
| tunnel->stats.tx_bytes += len; |
| session->stats.tx_packets++; |
| session->stats.tx_bytes += len; |
| } else { |
| tunnel->stats.tx_errors++; |
| session->stats.tx_errors++; |
| } |
| |
| sock_put(sk_tun); |
| sock_put(sk); |
| return 1; |
| |
| abort_put_sess_tun: |
| sock_put(sk_tun); |
| abort_put_sess: |
| sock_put(sk); |
| abort: |
| /* Free the original skb */ |
| kfree_skb(skb); |
| return 1; |
| } |
| |
| /***************************************************************************** |
| * Session (and tunnel control) socket create/destroy. |
| *****************************************************************************/ |
| |
| /* When the tunnel UDP socket is closed, all the attached sockets need to go |
| * too. |
| */ |
| static void pppol2tp_tunnel_closeall(struct pppol2tp_tunnel *tunnel) |
| { |
| int hash; |
| struct hlist_node *walk; |
| struct hlist_node *tmp; |
| struct pppol2tp_session *session; |
| struct sock *sk; |
| |
| if (tunnel == NULL) |
| BUG(); |
| |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: closing all sessions...\n", tunnel->name); |
| |
| write_lock_bh(&tunnel->hlist_lock); |
| for (hash = 0; hash < PPPOL2TP_HASH_SIZE; hash++) { |
| again: |
| hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { |
| struct sk_buff *skb; |
| |
| session = hlist_entry(walk, struct pppol2tp_session, hlist); |
| |
| sk = session->sock; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: closing session\n", session->name); |
| |
| hlist_del_init(&session->hlist); |
| |
| /* Since we should hold the sock lock while |
| * doing any unbinding, we need to release the |
| * lock we're holding before taking that lock. |
| * Hold a reference to the sock so it doesn't |
| * disappear as we're jumping between locks. |
| */ |
| sock_hold(sk); |
| write_unlock_bh(&tunnel->hlist_lock); |
| lock_sock(sk); |
| |
| if (sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)) { |
| pppox_unbind_sock(sk); |
| sk->sk_state = PPPOX_DEAD; |
| sk->sk_state_change(sk); |
| } |
| |
| /* Purge any queued data */ |
| skb_queue_purge(&sk->sk_receive_queue); |
| skb_queue_purge(&sk->sk_write_queue); |
| while ((skb = skb_dequeue(&session->reorder_q))) { |
| kfree_skb(skb); |
| sock_put(sk); |
| } |
| |
| release_sock(sk); |
| sock_put(sk); |
| |
| /* Now restart from the beginning of this hash |
| * chain. We always remove a session from the |
| * list so we are guaranteed to make forward |
| * progress. |
| */ |
| write_lock_bh(&tunnel->hlist_lock); |
| goto again; |
| } |
| } |
| write_unlock_bh(&tunnel->hlist_lock); |
| } |
| |
| /* Really kill the tunnel. |
| * Come here only when all sessions have been cleared from the tunnel. |
| */ |
| static void pppol2tp_tunnel_free(struct pppol2tp_tunnel *tunnel) |
| { |
| /* Remove from socket list */ |
| write_lock_bh(&pppol2tp_tunnel_list_lock); |
| list_del_init(&tunnel->list); |
| write_unlock_bh(&pppol2tp_tunnel_list_lock); |
| |
| atomic_dec(&pppol2tp_tunnel_count); |
| kfree(tunnel); |
| } |
| |
| /* Tunnel UDP socket destruct hook. |
| * The tunnel context is deleted only when all session sockets have been |
| * closed. |
| */ |
| static void pppol2tp_tunnel_destruct(struct sock *sk) |
| { |
| struct pppol2tp_tunnel *tunnel; |
| |
| tunnel = sk->sk_user_data; |
| if (tunnel == NULL) |
| goto end; |
| |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: closing...\n", tunnel->name); |
| |
| /* Close all sessions */ |
| pppol2tp_tunnel_closeall(tunnel); |
| |
| /* No longer an encapsulation socket. See net/ipv4/udp.c */ |
| (udp_sk(sk))->encap_type = 0; |
| (udp_sk(sk))->encap_rcv = NULL; |
| |
| /* Remove hooks into tunnel socket */ |
| tunnel->sock = NULL; |
| sk->sk_destruct = tunnel->old_sk_destruct; |
| sk->sk_user_data = NULL; |
| |
| /* Call original (UDP) socket descructor */ |
| if (sk->sk_destruct != NULL) |
| (*sk->sk_destruct)(sk); |
| |
| pppol2tp_tunnel_dec_refcount(tunnel); |
| |
| end: |
| return; |
| } |
| |
| /* Really kill the session socket. (Called from sock_put() if |
| * refcnt == 0.) |
| */ |
| static void pppol2tp_session_destruct(struct sock *sk) |
| { |
| struct pppol2tp_session *session = NULL; |
| |
| if (sk->sk_user_data != NULL) { |
| struct pppol2tp_tunnel *tunnel; |
| |
| session = sk->sk_user_data; |
| if (session == NULL) |
| goto out; |
| |
| BUG_ON(session->magic != L2TP_SESSION_MAGIC); |
| |
| /* Don't use pppol2tp_sock_to_tunnel() here to |
| * get the tunnel context because the tunnel |
| * socket might have already been closed (its |
| * sk->sk_user_data will be NULL) so use the |
| * session's private tunnel ptr instead. |
| */ |
| tunnel = session->tunnel; |
| if (tunnel != NULL) { |
| BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| |
| /* If session_id is zero, this is a null |
| * session context, which was created for a |
| * socket that is being used only to manage |
| * tunnels. |
| */ |
| if (session->tunnel_addr.s_session != 0) { |
| /* Delete the session socket from the |
| * hash |
| */ |
| write_lock_bh(&tunnel->hlist_lock); |
| hlist_del_init(&session->hlist); |
| write_unlock_bh(&tunnel->hlist_lock); |
| |
| atomic_dec(&pppol2tp_session_count); |
| } |
| |
| /* This will delete the tunnel context if this |
| * is the last session on the tunnel. |
| */ |
| session->tunnel = NULL; |
| session->tunnel_sock = NULL; |
| pppol2tp_tunnel_dec_refcount(tunnel); |
| } |
| } |
| |
| kfree(session); |
| out: |
| return; |
| } |
| |
| /* Called when the PPPoX socket (session) is closed. |
| */ |
| static int pppol2tp_release(struct socket *sock) |
| { |
| struct sock *sk = sock->sk; |
| struct pppol2tp_session *session; |
| int error; |
| |
| if (!sk) |
| return 0; |
| |
| error = -EBADF; |
| lock_sock(sk); |
| if (sock_flag(sk, SOCK_DEAD) != 0) |
| goto error; |
| |
| pppox_unbind_sock(sk); |
| |
| /* Signal the death of the socket. */ |
| sk->sk_state = PPPOX_DEAD; |
| sock_orphan(sk); |
| sock->sk = NULL; |
| |
| session = pppol2tp_sock_to_session(sk); |
| |
| /* Purge any queued data */ |
| skb_queue_purge(&sk->sk_receive_queue); |
| skb_queue_purge(&sk->sk_write_queue); |
| if (session != NULL) { |
| struct sk_buff *skb; |
| while ((skb = skb_dequeue(&session->reorder_q))) { |
| kfree_skb(skb); |
| sock_put(sk); |
| } |
| } |
| |
| release_sock(sk); |
| |
| /* This will delete the session context via |
| * pppol2tp_session_destruct() if the socket's refcnt drops to |
| * zero. |
| */ |
| sock_put(sk); |
| |
| return 0; |
| |
| error: |
| release_sock(sk); |
| return error; |
| } |
| |
| /* Internal function to prepare a tunnel (UDP) socket to have PPPoX |
| * sockets attached to it. |
| */ |
| static struct sock *pppol2tp_prepare_tunnel_socket(int fd, u16 tunnel_id, |
| int *error) |
| { |
| int err; |
| struct socket *sock = NULL; |
| struct sock *sk; |
| struct pppol2tp_tunnel *tunnel; |
| struct sock *ret = NULL; |
| |
| /* Get the tunnel UDP socket from the fd, which was opened by |
| * the userspace L2TP daemon. |
| */ |
| err = -EBADF; |
| sock = sockfd_lookup(fd, &err); |
| if (!sock) { |
| PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, |
| "tunl %hu: sockfd_lookup(fd=%d) returned %d\n", |
| tunnel_id, fd, err); |
| goto err; |
| } |
| |
| sk = sock->sk; |
| |
| /* Quick sanity checks */ |
| err = -EPROTONOSUPPORT; |
| if (sk->sk_protocol != IPPROTO_UDP) { |
| PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, |
| "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", |
| tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); |
| goto err; |
| } |
| err = -EAFNOSUPPORT; |
| if (sock->ops->family != AF_INET) { |
| PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR, |
| "tunl %hu: fd %d wrong family, got %d, expected %d\n", |
| tunnel_id, fd, sock->ops->family, AF_INET); |
| goto err; |
| } |
| |
| err = -ENOTCONN; |
| |
| /* Check if this socket has already been prepped */ |
| tunnel = (struct pppol2tp_tunnel *)sk->sk_user_data; |
| if (tunnel != NULL) { |
| /* User-data field already set */ |
| err = -EBUSY; |
| BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| |
| /* This socket has already been prepped */ |
| ret = tunnel->sock; |
| goto out; |
| } |
| |
| /* This socket is available and needs prepping. Create a new tunnel |
| * context and init it. |
| */ |
| sk->sk_user_data = tunnel = kzalloc(sizeof(struct pppol2tp_tunnel), GFP_KERNEL); |
| if (sk->sk_user_data == NULL) { |
| err = -ENOMEM; |
| goto err; |
| } |
| |
| tunnel->magic = L2TP_TUNNEL_MAGIC; |
| sprintf(&tunnel->name[0], "tunl %hu", tunnel_id); |
| |
| tunnel->stats.tunnel_id = tunnel_id; |
| tunnel->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS; |
| |
| /* Hook on the tunnel socket destructor so that we can cleanup |
| * if the tunnel socket goes away. |
| */ |
| tunnel->old_sk_destruct = sk->sk_destruct; |
| sk->sk_destruct = &pppol2tp_tunnel_destruct; |
| |
| tunnel->sock = sk; |
| sk->sk_allocation = GFP_ATOMIC; |
| |
| /* Misc init */ |
| rwlock_init(&tunnel->hlist_lock); |
| |
| /* Add tunnel to our list */ |
| INIT_LIST_HEAD(&tunnel->list); |
| write_lock_bh(&pppol2tp_tunnel_list_lock); |
| list_add(&tunnel->list, &pppol2tp_tunnel_list); |
| write_unlock_bh(&pppol2tp_tunnel_list_lock); |
| atomic_inc(&pppol2tp_tunnel_count); |
| |
| /* Bump the reference count. The tunnel context is deleted |
| * only when this drops to zero. |
| */ |
| pppol2tp_tunnel_inc_refcount(tunnel); |
| |
| /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ |
| (udp_sk(sk))->encap_type = UDP_ENCAP_L2TPINUDP; |
| (udp_sk(sk))->encap_rcv = pppol2tp_udp_encap_recv; |
| |
| ret = tunnel->sock; |
| |
| *error = 0; |
| out: |
| if (sock) |
| sockfd_put(sock); |
| |
| return ret; |
| |
| err: |
| *error = err; |
| goto out; |
| } |
| |
| static struct proto pppol2tp_sk_proto = { |
| .name = "PPPOL2TP", |
| .owner = THIS_MODULE, |
| .obj_size = sizeof(struct pppox_sock), |
| }; |
| |
| /* socket() handler. Initialize a new struct sock. |
| */ |
| static int pppol2tp_create(struct net *net, struct socket *sock) |
| { |
| int error = -ENOMEM; |
| struct sock *sk; |
| |
| sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto); |
| if (!sk) |
| goto out; |
| |
| sock_init_data(sock, sk); |
| |
| sock->state = SS_UNCONNECTED; |
| sock->ops = &pppol2tp_ops; |
| |
| sk->sk_backlog_rcv = pppol2tp_recv_core; |
| sk->sk_protocol = PX_PROTO_OL2TP; |
| sk->sk_family = PF_PPPOX; |
| sk->sk_state = PPPOX_NONE; |
| sk->sk_type = SOCK_STREAM; |
| sk->sk_destruct = pppol2tp_session_destruct; |
| |
| error = 0; |
| |
| out: |
| return error; |
| } |
| |
| /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket |
| */ |
| static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, |
| int sockaddr_len, int flags) |
| { |
| struct sock *sk = sock->sk; |
| struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; |
| struct pppox_sock *po = pppox_sk(sk); |
| struct sock *tunnel_sock = NULL; |
| struct pppol2tp_session *session = NULL; |
| struct pppol2tp_tunnel *tunnel; |
| struct dst_entry *dst; |
| int error = 0; |
| |
| lock_sock(sk); |
| |
| error = -EINVAL; |
| if (sp->sa_protocol != PX_PROTO_OL2TP) |
| goto end; |
| |
| /* Check for already bound sockets */ |
| error = -EBUSY; |
| if (sk->sk_state & PPPOX_CONNECTED) |
| goto end; |
| |
| /* We don't supporting rebinding anyway */ |
| error = -EALREADY; |
| if (sk->sk_user_data) |
| goto end; /* socket is already attached */ |
| |
| /* Don't bind if s_tunnel is 0 */ |
| error = -EINVAL; |
| if (sp->pppol2tp.s_tunnel == 0) |
| goto end; |
| |
| /* Special case: prepare tunnel socket if s_session and |
| * d_session is 0. Otherwise look up tunnel using supplied |
| * tunnel id. |
| */ |
| if ((sp->pppol2tp.s_session == 0) && (sp->pppol2tp.d_session == 0)) { |
| tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.fd, |
| sp->pppol2tp.s_tunnel, |
| &error); |
| if (tunnel_sock == NULL) |
| goto end; |
| |
| tunnel = tunnel_sock->sk_user_data; |
| } else { |
| tunnel = pppol2tp_tunnel_find(sp->pppol2tp.s_tunnel); |
| |
| /* Error if we can't find the tunnel */ |
| error = -ENOENT; |
| if (tunnel == NULL) |
| goto end; |
| |
| tunnel_sock = tunnel->sock; |
| } |
| |
| /* Check that this session doesn't already exist */ |
| error = -EEXIST; |
| session = pppol2tp_session_find(tunnel, sp->pppol2tp.s_session); |
| if (session != NULL) |
| goto end; |
| |
| /* Allocate and initialize a new session context. */ |
| session = kzalloc(sizeof(struct pppol2tp_session), GFP_KERNEL); |
| if (session == NULL) { |
| error = -ENOMEM; |
| goto end; |
| } |
| |
| skb_queue_head_init(&session->reorder_q); |
| |
| session->magic = L2TP_SESSION_MAGIC; |
| session->owner = current->pid; |
| session->sock = sk; |
| session->tunnel = tunnel; |
| session->tunnel_sock = tunnel_sock; |
| session->tunnel_addr = sp->pppol2tp; |
| sprintf(&session->name[0], "sess %hu/%hu", |
| session->tunnel_addr.s_tunnel, |
| session->tunnel_addr.s_session); |
| |
| session->stats.tunnel_id = session->tunnel_addr.s_tunnel; |
| session->stats.session_id = session->tunnel_addr.s_session; |
| |
| INIT_HLIST_NODE(&session->hlist); |
| |
| /* Inherit debug options from tunnel */ |
| session->debug = tunnel->debug; |
| |
| /* Default MTU must allow space for UDP/L2TP/PPP |
| * headers. |
| */ |
| session->mtu = session->mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; |
| |
| /* If PMTU discovery was enabled, use the MTU that was discovered */ |
| dst = sk_dst_get(sk); |
| if (dst != NULL) { |
| u32 pmtu = dst_mtu(__sk_dst_get(sk)); |
| if (pmtu != 0) |
| session->mtu = session->mru = pmtu - |
| PPPOL2TP_HEADER_OVERHEAD; |
| dst_release(dst); |
| } |
| |
| /* Special case: if source & dest session_id == 0x0000, this socket is |
| * being created to manage the tunnel. Don't add the session to the |
| * session hash list, just set up the internal context for use by |
| * ioctl() and sockopt() handlers. |
| */ |
| if ((session->tunnel_addr.s_session == 0) && |
| (session->tunnel_addr.d_session == 0)) { |
| error = 0; |
| sk->sk_user_data = session; |
| goto out_no_ppp; |
| } |
| |
| /* Get tunnel context from the tunnel socket */ |
| tunnel = pppol2tp_sock_to_tunnel(tunnel_sock); |
| if (tunnel == NULL) { |
| error = -EBADF; |
| goto end; |
| } |
| |
| /* Right now, because we don't have a way to push the incoming skb's |
| * straight through the UDP layer, the only header we need to worry |
| * about is the L2TP header. This size is different depending on |
| * whether sequence numbers are enabled for the data channel. |
| */ |
| po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; |
| |
| po->chan.private = sk; |
| po->chan.ops = &pppol2tp_chan_ops; |
| po->chan.mtu = session->mtu; |
| |
| error = ppp_register_channel(&po->chan); |
| if (error) |
| goto end_put_tun; |
| |
| /* This is how we get the session context from the socket. */ |
| sk->sk_user_data = session; |
| |
| /* Add session to the tunnel's hash list */ |
| write_lock_bh(&tunnel->hlist_lock); |
| hlist_add_head(&session->hlist, |
| pppol2tp_session_id_hash(tunnel, |
| session->tunnel_addr.s_session)); |
| write_unlock_bh(&tunnel->hlist_lock); |
| |
| atomic_inc(&pppol2tp_session_count); |
| |
| out_no_ppp: |
| pppol2tp_tunnel_inc_refcount(tunnel); |
| sk->sk_state = PPPOX_CONNECTED; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: created\n", session->name); |
| |
| end_put_tun: |
| sock_put(tunnel_sock); |
| end: |
| release_sock(sk); |
| |
| if (error != 0) { |
| if (session) |
| PRINTK(session->debug, |
| PPPOL2TP_MSG_CONTROL, KERN_WARNING, |
| "%s: connect failed: %d\n", |
| session->name, error); |
| else |
| PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_WARNING, |
| "connect failed: %d\n", error); |
| } |
| |
| return error; |
| } |
| |
| /* getname() support. |
| */ |
| static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, |
| int *usockaddr_len, int peer) |
| { |
| int len = sizeof(struct sockaddr_pppol2tp); |
| struct sockaddr_pppol2tp sp; |
| int error = 0; |
| struct pppol2tp_session *session; |
| |
| error = -ENOTCONN; |
| if (sock->sk->sk_state != PPPOX_CONNECTED) |
| goto end; |
| |
| session = pppol2tp_sock_to_session(sock->sk); |
| if (session == NULL) { |
| error = -EBADF; |
| goto end; |
| } |
| |
| sp.sa_family = AF_PPPOX; |
| sp.sa_protocol = PX_PROTO_OL2TP; |
| memcpy(&sp.pppol2tp, &session->tunnel_addr, |
| sizeof(struct pppol2tp_addr)); |
| |
| memcpy(uaddr, &sp, len); |
| |
| *usockaddr_len = len; |
| |
| error = 0; |
| sock_put(sock->sk); |
| |
| end: |
| return error; |
| } |
| |
| /**************************************************************************** |
| * ioctl() handlers. |
| * |
| * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP |
| * sockets. However, in order to control kernel tunnel features, we allow |
| * userspace to create a special "tunnel" PPPoX socket which is used for |
| * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow |
| * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() |
| * calls. |
| ****************************************************************************/ |
| |
| /* Session ioctl helper. |
| */ |
| static int pppol2tp_session_ioctl(struct pppol2tp_session *session, |
| unsigned int cmd, unsigned long arg) |
| { |
| struct ifreq ifr; |
| int err = 0; |
| struct sock *sk = session->sock; |
| int val = (int) arg; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, |
| "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", |
| session->name, cmd, arg); |
| |
| sock_hold(sk); |
| |
| switch (cmd) { |
| case SIOCGIFMTU: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| err = -EFAULT; |
| if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) |
| break; |
| ifr.ifr_mtu = session->mtu; |
| if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) |
| break; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get mtu=%d\n", session->name, session->mtu); |
| err = 0; |
| break; |
| |
| case SIOCSIFMTU: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| err = -EFAULT; |
| if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) |
| break; |
| |
| session->mtu = ifr.ifr_mtu; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set mtu=%d\n", session->name, session->mtu); |
| err = 0; |
| break; |
| |
| case PPPIOCGMRU: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| err = -EFAULT; |
| if (put_user(session->mru, (int __user *) arg)) |
| break; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get mru=%d\n", session->name, session->mru); |
| err = 0; |
| break; |
| |
| case PPPIOCSMRU: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| err = -EFAULT; |
| if (get_user(val,(int __user *) arg)) |
| break; |
| |
| session->mru = val; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set mru=%d\n", session->name, session->mru); |
| err = 0; |
| break; |
| |
| case PPPIOCGFLAGS: |
| err = -EFAULT; |
| if (put_user(session->flags, (int __user *) arg)) |
| break; |
| |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get flags=%d\n", session->name, session->flags); |
| err = 0; |
| break; |
| |
| case PPPIOCSFLAGS: |
| err = -EFAULT; |
| if (get_user(val, (int __user *) arg)) |
| break; |
| session->flags = val; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set flags=%d\n", session->name, session->flags); |
| err = 0; |
| break; |
| |
| case PPPIOCGL2TPSTATS: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| if (copy_to_user((void __user *) arg, &session->stats, |
| sizeof(session->stats))) |
| break; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get L2TP stats\n", session->name); |
| err = 0; |
| break; |
| |
| default: |
| err = -ENOSYS; |
| break; |
| } |
| |
| sock_put(sk); |
| |
| return err; |
| } |
| |
| /* Tunnel ioctl helper. |
| * |
| * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data |
| * specifies a session_id, the session ioctl handler is called. This allows an |
| * application to retrieve session stats via a tunnel socket. |
| */ |
| static int pppol2tp_tunnel_ioctl(struct pppol2tp_tunnel *tunnel, |
| unsigned int cmd, unsigned long arg) |
| { |
| int err = 0; |
| struct sock *sk = tunnel->sock; |
| struct pppol2tp_ioc_stats stats_req; |
| |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_DEBUG, |
| "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", tunnel->name, |
| cmd, arg); |
| |
| sock_hold(sk); |
| |
| switch (cmd) { |
| case PPPIOCGL2TPSTATS: |
| err = -ENXIO; |
| if (!(sk->sk_state & PPPOX_CONNECTED)) |
| break; |
| |
| if (copy_from_user(&stats_req, (void __user *) arg, |
| sizeof(stats_req))) { |
| err = -EFAULT; |
| break; |
| } |
| if (stats_req.session_id != 0) { |
| /* resend to session ioctl handler */ |
| struct pppol2tp_session *session = |
| pppol2tp_session_find(tunnel, stats_req.session_id); |
| if (session != NULL) |
| err = pppol2tp_session_ioctl(session, cmd, arg); |
| else |
| err = -EBADR; |
| break; |
| } |
| #ifdef CONFIG_XFRM |
| tunnel->stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; |
| #endif |
| if (copy_to_user((void __user *) arg, &tunnel->stats, |
| sizeof(tunnel->stats))) { |
| err = -EFAULT; |
| break; |
| } |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get L2TP stats\n", tunnel->name); |
| err = 0; |
| break; |
| |
| default: |
| err = -ENOSYS; |
| break; |
| } |
| |
| sock_put(sk); |
| |
| return err; |
| } |
| |
| /* Main ioctl() handler. |
| * Dispatch to tunnel or session helpers depending on the socket. |
| */ |
| static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct sock *sk = sock->sk; |
| struct pppol2tp_session *session; |
| struct pppol2tp_tunnel *tunnel; |
| int err; |
| |
| if (!sk) |
| return 0; |
| |
| err = -EBADF; |
| if (sock_flag(sk, SOCK_DEAD) != 0) |
| goto end; |
| |
| err = -ENOTCONN; |
| if ((sk->sk_user_data == NULL) || |
| (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) |
| goto end; |
| |
| /* Get session context from the socket */ |
| err = -EBADF; |
| session = pppol2tp_sock_to_session(sk); |
| if (session == NULL) |
| goto end; |
| |
| /* Special case: if session's session_id is zero, treat ioctl as a |
| * tunnel ioctl |
| */ |
| if ((session->tunnel_addr.s_session == 0) && |
| (session->tunnel_addr.d_session == 0)) { |
| err = -EBADF; |
| tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); |
| if (tunnel == NULL) |
| goto end_put_sess; |
| |
| err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); |
| sock_put(session->tunnel_sock); |
| goto end_put_sess; |
| } |
| |
| err = pppol2tp_session_ioctl(session, cmd, arg); |
| |
| end_put_sess: |
| sock_put(sk); |
| end: |
| return err; |
| } |
| |
| /***************************************************************************** |
| * setsockopt() / getsockopt() support. |
| * |
| * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP |
| * sockets. In order to control kernel tunnel features, we allow userspace to |
| * create a special "tunnel" PPPoX socket which is used for control only. |
| * Tunnel PPPoX sockets have session_id == 0 and simply allow the user |
| * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. |
| *****************************************************************************/ |
| |
| /* Tunnel setsockopt() helper. |
| */ |
| static int pppol2tp_tunnel_setsockopt(struct sock *sk, |
| struct pppol2tp_tunnel *tunnel, |
| int optname, int val) |
| { |
| int err = 0; |
| |
| switch (optname) { |
| case PPPOL2TP_SO_DEBUG: |
| tunnel->debug = val; |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set debug=%x\n", tunnel->name, tunnel->debug); |
| break; |
| |
| default: |
| err = -ENOPROTOOPT; |
| break; |
| } |
| |
| return err; |
| } |
| |
| /* Session setsockopt helper. |
| */ |
| static int pppol2tp_session_setsockopt(struct sock *sk, |
| struct pppol2tp_session *session, |
| int optname, int val) |
| { |
| int err = 0; |
| |
| switch (optname) { |
| case PPPOL2TP_SO_RECVSEQ: |
| if ((val != 0) && (val != 1)) { |
| err = -EINVAL; |
| break; |
| } |
| session->recv_seq = val ? -1 : 0; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set recv_seq=%d\n", session->name, |
| session->recv_seq); |
| break; |
| |
| case PPPOL2TP_SO_SENDSEQ: |
| if ((val != 0) && (val != 1)) { |
| err = -EINVAL; |
| break; |
| } |
| session->send_seq = val ? -1 : 0; |
| { |
| struct sock *ssk = session->sock; |
| struct pppox_sock *po = pppox_sk(ssk); |
| po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : |
| PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; |
| } |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set send_seq=%d\n", session->name, session->send_seq); |
| break; |
| |
| case PPPOL2TP_SO_LNSMODE: |
| if ((val != 0) && (val != 1)) { |
| err = -EINVAL; |
| break; |
| } |
| session->lns_mode = val ? -1 : 0; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set lns_mode=%d\n", session->name, |
| session->lns_mode); |
| break; |
| |
| case PPPOL2TP_SO_DEBUG: |
| session->debug = val; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set debug=%x\n", session->name, session->debug); |
| break; |
| |
| case PPPOL2TP_SO_REORDERTO: |
| session->reorder_timeout = msecs_to_jiffies(val); |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: set reorder_timeout=%d\n", session->name, |
| session->reorder_timeout); |
| break; |
| |
| default: |
| err = -ENOPROTOOPT; |
| break; |
| } |
| |
| return err; |
| } |
| |
| /* Main setsockopt() entry point. |
| * Does API checks, then calls either the tunnel or session setsockopt |
| * handler, according to whether the PPPoL2TP socket is a for a regular |
| * session or the special tunnel type. |
| */ |
| static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, |
| char __user *optval, int optlen) |
| { |
| struct sock *sk = sock->sk; |
| struct pppol2tp_session *session = sk->sk_user_data; |
| struct pppol2tp_tunnel *tunnel; |
| int val; |
| int err; |
| |
| if (level != SOL_PPPOL2TP) |
| return udp_prot.setsockopt(sk, level, optname, optval, optlen); |
| |
| if (optlen < sizeof(int)) |
| return -EINVAL; |
| |
| if (get_user(val, (int __user *)optval)) |
| return -EFAULT; |
| |
| err = -ENOTCONN; |
| if (sk->sk_user_data == NULL) |
| goto end; |
| |
| /* Get session context from the socket */ |
| err = -EBADF; |
| session = pppol2tp_sock_to_session(sk); |
| if (session == NULL) |
| goto end; |
| |
| /* Special case: if session_id == 0x0000, treat as operation on tunnel |
| */ |
| if ((session->tunnel_addr.s_session == 0) && |
| (session->tunnel_addr.d_session == 0)) { |
| err = -EBADF; |
| tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); |
| if (tunnel == NULL) |
| goto end_put_sess; |
| |
| err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); |
| sock_put(session->tunnel_sock); |
| } else |
| err = pppol2tp_session_setsockopt(sk, session, optname, val); |
| |
| err = 0; |
| |
| end_put_sess: |
| sock_put(sk); |
| end: |
| return err; |
| } |
| |
| /* Tunnel getsockopt helper. Called with sock locked. |
| */ |
| static int pppol2tp_tunnel_getsockopt(struct sock *sk, |
| struct pppol2tp_tunnel *tunnel, |
| int optname, int *val) |
| { |
| int err = 0; |
| |
| switch (optname) { |
| case PPPOL2TP_SO_DEBUG: |
| *val = tunnel->debug; |
| PRINTK(tunnel->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get debug=%x\n", tunnel->name, tunnel->debug); |
| break; |
| |
| default: |
| err = -ENOPROTOOPT; |
| break; |
| } |
| |
| return err; |
| } |
| |
| /* Session getsockopt helper. Called with sock locked. |
| */ |
| static int pppol2tp_session_getsockopt(struct sock *sk, |
| struct pppol2tp_session *session, |
| int optname, int *val) |
| { |
| int err = 0; |
| |
| switch (optname) { |
| case PPPOL2TP_SO_RECVSEQ: |
| *val = session->recv_seq; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get recv_seq=%d\n", session->name, *val); |
| break; |
| |
| case PPPOL2TP_SO_SENDSEQ: |
| *val = session->send_seq; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get send_seq=%d\n", session->name, *val); |
| break; |
| |
| case PPPOL2TP_SO_LNSMODE: |
| *val = session->lns_mode; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get lns_mode=%d\n", session->name, *val); |
| break; |
| |
| case PPPOL2TP_SO_DEBUG: |
| *val = session->debug; |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get debug=%d\n", session->name, *val); |
| break; |
| |
| case PPPOL2TP_SO_REORDERTO: |
| *val = (int) jiffies_to_msecs(session->reorder_timeout); |
| PRINTK(session->debug, PPPOL2TP_MSG_CONTROL, KERN_INFO, |
| "%s: get reorder_timeout=%d\n", session->name, *val); |
| break; |
| |
| default: |
| err = -ENOPROTOOPT; |
| } |
| |
| return err; |
| } |
| |
| /* Main getsockopt() entry point. |
| * Does API checks, then calls either the tunnel or session getsockopt |
| * handler, according to whether the PPPoX socket is a for a regular session |
| * or the special tunnel type. |
| */ |
| static int pppol2tp_getsockopt(struct socket *sock, int level, |
| int optname, char __user *optval, int __user *optlen) |
| { |
| struct sock *sk = sock->sk; |
| struct pppol2tp_session *session = sk->sk_user_data; |
| struct pppol2tp_tunnel *tunnel; |
| int val, len; |
| int err; |
| |
| if (level != SOL_PPPOL2TP) |
| return udp_prot.getsockopt(sk, level, optname, optval, optlen); |
| |
| if (get_user(len, (int __user *) optlen)) |
| return -EFAULT; |
| |
| len = min_t(unsigned int, len, sizeof(int)); |
| |
| if (len < 0) |
| return -EINVAL; |
| |
| err = -ENOTCONN; |
| if (sk->sk_user_data == NULL) |
| goto end; |
| |
| /* Get the session context */ |
| err = -EBADF; |
| session = pppol2tp_sock_to_session(sk); |
| if (session == NULL) |
| goto end; |
| |
| /* Special case: if session_id == 0x0000, treat as operation on tunnel */ |
| if ((session->tunnel_addr.s_session == 0) && |
| (session->tunnel_addr.d_session == 0)) { |
| err = -EBADF; |
| tunnel = pppol2tp_sock_to_tunnel(session->tunnel_sock); |
| if (tunnel == NULL) |
| goto end_put_sess; |
| |
| err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); |
| sock_put(session->tunnel_sock); |
| } else |
| err = pppol2tp_session_getsockopt(sk, session, optname, &val); |
| |
| err = -EFAULT; |
| if (put_user(len, (int __user *) optlen)) |
| goto end_put_sess; |
| |
| if (copy_to_user((void __user *) optval, &val, len)) |
| goto end_put_sess; |
| |
| err = 0; |
| |
| end_put_sess: |
| sock_put(sk); |
| end: |
| return err; |
| } |
| |
| /***************************************************************************** |
| * /proc filesystem for debug |
| *****************************************************************************/ |
| |
| #ifdef CONFIG_PROC_FS |
| |
| #include <linux/seq_file.h> |
| |
| struct pppol2tp_seq_data { |
| struct pppol2tp_tunnel *tunnel; /* current tunnel */ |
| struct pppol2tp_session *session; /* NULL means get first session in tunnel */ |
| }; |
| |
| static struct pppol2tp_session *next_session(struct pppol2tp_tunnel *tunnel, struct pppol2tp_session *curr) |
| { |
| struct pppol2tp_session *session = NULL; |
| struct hlist_node *walk; |
| int found = 0; |
| int next = 0; |
| int i; |
| |
| read_lock_bh(&tunnel->hlist_lock); |
| for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) { |
| hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) { |
| if (curr == NULL) { |
| found = 1; |
| goto out; |
| } |
| if (session == curr) { |
| next = 1; |
| continue; |
| } |
| if (next) { |
| found = 1; |
| goto out; |
| } |
| } |
| } |
| out: |
| read_unlock_bh(&tunnel->hlist_lock); |
| if (!found) |
| session = NULL; |
| |
| return session; |
| } |
| |
| static struct pppol2tp_tunnel *next_tunnel(struct pppol2tp_tunnel *curr) |
| { |
| struct pppol2tp_tunnel *tunnel = NULL; |
| |
| read_lock_bh(&pppol2tp_tunnel_list_lock); |
| if (list_is_last(&curr->list, &pppol2tp_tunnel_list)) { |
| goto out; |
| } |
| tunnel = list_entry(curr->list.next, struct pppol2tp_tunnel, list); |
| out: |
| read_unlock_bh(&pppol2tp_tunnel_list_lock); |
| |
| return tunnel; |
| } |
| |
| static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) |
| { |
| struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; |
| loff_t pos = *offs; |
| |
| if (!pos) |
| goto out; |
| |
| BUG_ON(m->private == NULL); |
| pd = m->private; |
| |
| if (pd->tunnel == NULL) { |
| if (!list_empty(&pppol2tp_tunnel_list)) |
| pd->tunnel = list_entry(pppol2tp_tunnel_list.next, struct pppol2tp_tunnel, list); |
| } else { |
| pd->session = next_session(pd->tunnel, pd->session); |
| if (pd->session == NULL) { |
| pd->tunnel = next_tunnel(pd->tunnel); |
| } |
| } |
| |
| /* NULL tunnel and session indicates end of list */ |
| if ((pd->tunnel == NULL) && (pd->session == NULL)) |
| pd = NULL; |
| |
| out: |
| return pd; |
| } |
| |
| static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) |
| { |
| (*pos)++; |
| return NULL; |
| } |
| |
| static void pppol2tp_seq_stop(struct seq_file *p, void *v) |
| { |
| /* nothing to do */ |
| } |
| |
| static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) |
| { |
| struct pppol2tp_tunnel *tunnel = v; |
| |
| seq_printf(m, "\nTUNNEL '%s', %c %d\n", |
| tunnel->name, |
| (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N', |
| atomic_read(&tunnel->ref_count) - 1); |
| seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n", |
| tunnel->debug, |
| (unsigned long long)tunnel->stats.tx_packets, |
| (unsigned long long)tunnel->stats.tx_bytes, |
| (unsigned long long)tunnel->stats.tx_errors, |
| (unsigned long long)tunnel->stats.rx_packets, |
| (unsigned long long)tunnel->stats.rx_bytes, |
| (unsigned long long)tunnel->stats.rx_errors); |
| } |
| |
| static void pppol2tp_seq_session_show(struct seq_file *m, void *v) |
| { |
| struct pppol2tp_session *session = v; |
| |
| seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " |
| "%04X/%04X %d %c\n", |
| session->name, |
| ntohl(session->tunnel_addr.addr.sin_addr.s_addr), |
| ntohs(session->tunnel_addr.addr.sin_port), |
| session->tunnel_addr.s_tunnel, |
| session->tunnel_addr.s_session, |
| session->tunnel_addr.d_tunnel, |
| session->tunnel_addr.d_session, |
| session->sock->sk_state, |
| (session == session->sock->sk_user_data) ? |
| 'Y' : 'N'); |
| seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", |
| session->mtu, session->mru, |
| session->recv_seq ? 'R' : '-', |
| session->send_seq ? 'S' : '-', |
| session->lns_mode ? "LNS" : "LAC", |
| session->debug, |
| jiffies_to_msecs(session->reorder_timeout)); |
| seq_printf(m, " %hu/%hu %llu/%llu/%llu %llu/%llu/%llu\n", |
| session->nr, session->ns, |
| (unsigned long long)session->stats.tx_packets, |
| (unsigned long long)session->stats.tx_bytes, |
| (unsigned long long)session->stats.tx_errors, |
| (unsigned long long)session->stats.rx_packets, |
| (unsigned long long)session->stats.rx_bytes, |
| (unsigned long long)session->stats.rx_errors); |
| } |
| |
| static int pppol2tp_seq_show(struct seq_file *m, void *v) |
| { |
| struct pppol2tp_seq_data *pd = v; |
| |
| /* display header on line 1 */ |
| if (v == SEQ_START_TOKEN) { |
| seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); |
| seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); |
| seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); |
| seq_puts(m, " SESSION name, addr/port src-tid/sid " |
| "dest-tid/sid state user-data-ok\n"); |
| seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); |
| seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); |
| goto out; |
| } |
| |
| /* Show the tunnel or session context. |
| */ |
| if (pd->session == NULL) |
| pppol2tp_seq_tunnel_show(m, pd->tunnel); |
| else |
| pppol2tp_seq_session_show(m, pd->session); |
| |
| out: |
| return 0; |
| } |
| |
| static struct seq_operations pppol2tp_seq_ops = { |
| .start = pppol2tp_seq_start, |
| .next = pppol2tp_seq_next, |
| .stop = pppol2tp_seq_stop, |
| .show = pppol2tp_seq_show, |
| }; |
| |
| /* Called when our /proc file is opened. We allocate data for use when |
| * iterating our tunnel / session contexts and store it in the private |
| * data of the seq_file. |
| */ |
| static int pppol2tp_proc_open(struct inode *inode, struct file *file) |
| { |
| struct seq_file *m; |
| struct pppol2tp_seq_data *pd; |
| int ret = 0; |
| |
| ret = seq_open(file, &pppol2tp_seq_ops); |
| if (ret < 0) |
| goto out; |
| |
| m = file->private_data; |
| |
| /* Allocate and fill our proc_data for access later */ |
| ret = -ENOMEM; |
| m->private = kzalloc(sizeof(struct pppol2tp_seq_data), GFP_KERNEL); |
| if (m->private == NULL) |
| goto out; |
| |
| pd = m->private; |
| ret = 0; |
| |
| out: |
| return ret; |
| } |
| |
| /* Called when /proc file access completes. |
| */ |
| static int pppol2tp_proc_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *m = (struct seq_file *)file->private_data; |
| |
| kfree(m->private); |
| m->private = NULL; |
| |
| return seq_release(inode, file); |
| } |
| |
| static struct file_operations pppol2tp_proc_fops = { |
| .owner = THIS_MODULE, |
| .open = pppol2tp_proc_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = pppol2tp_proc_release, |
| }; |
| |
| static struct proc_dir_entry *pppol2tp_proc; |
| |
| #endif /* CONFIG_PROC_FS */ |
| |
| /***************************************************************************** |
| * Init and cleanup |
| *****************************************************************************/ |
| |
| static struct proto_ops pppol2tp_ops = { |
| .family = AF_PPPOX, |
| .owner = THIS_MODULE, |
| .release = pppol2tp_release, |
| .bind = sock_no_bind, |
| .connect = pppol2tp_connect, |
| .socketpair = sock_no_socketpair, |
| .accept = sock_no_accept, |
| .getname = pppol2tp_getname, |
| .poll = datagram_poll, |
| .listen = sock_no_listen, |
| .shutdown = sock_no_shutdown, |
| .setsockopt = pppol2tp_setsockopt, |
| .getsockopt = pppol2tp_getsockopt, |
| .sendmsg = pppol2tp_sendmsg, |
| .recvmsg = pppol2tp_recvmsg, |
| .mmap = sock_no_mmap, |
| .ioctl = pppox_ioctl, |
| }; |
| |
| static struct pppox_proto pppol2tp_proto = { |
| .create = pppol2tp_create, |
| .ioctl = pppol2tp_ioctl |
| }; |
| |
| static int __init pppol2tp_init(void) |
| { |
| int err; |
| |
| err = proto_register(&pppol2tp_sk_proto, 0); |
| if (err) |
| goto out; |
| err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); |
| if (err) |
| goto out_unregister_pppol2tp_proto; |
| |
| #ifdef CONFIG_PROC_FS |
| pppol2tp_proc = proc_net_fops_create(&init_net, "pppol2tp", 0, |
| &pppol2tp_proc_fops); |
| if (!pppol2tp_proc) { |
| err = -ENOMEM; |
| goto out_unregister_pppox_proto; |
| } |
| #endif /* CONFIG_PROC_FS */ |
| printk(KERN_INFO "PPPoL2TP kernel driver, %s\n", |
| PPPOL2TP_DRV_VERSION); |
| |
| out: |
| return err; |
| #ifdef CONFIG_PROC_FS |
| out_unregister_pppox_proto: |
| unregister_pppox_proto(PX_PROTO_OL2TP); |
| #endif |
| out_unregister_pppol2tp_proto: |
| proto_unregister(&pppol2tp_sk_proto); |
| goto out; |
| } |
| |
| static void __exit pppol2tp_exit(void) |
| { |
| unregister_pppox_proto(PX_PROTO_OL2TP); |
| |
| #ifdef CONFIG_PROC_FS |
| remove_proc_entry("pppol2tp", init_net.proc_net); |
| #endif |
| proto_unregister(&pppol2tp_sk_proto); |
| } |
| |
| module_init(pppol2tp_init); |
| module_exit(pppol2tp_exit); |
| |
| MODULE_AUTHOR("Martijn van Oosterhout <kleptog@svana.org>, " |
| "James Chapman <jchapman@katalix.com>"); |
| MODULE_DESCRIPTION("PPP over L2TP over UDP"); |
| MODULE_LICENSE("GPL"); |
| MODULE_VERSION(PPPOL2TP_DRV_VERSION); |