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Date: Mon, 23 Apr 2007 13:56:40 +0100
From: James Chapman <jchapman@...alix.com>
To: netdev@...r.kernel.org
Subject: [PATCH 1/5 2.6.21-rc7] l2tp: pppol2tp core
[L2TP]: Add PPP-over-L2TP driver core.
This driver handles only L2TP data frames; control frames are handled
by a userspace application. It implements L2TP using the PPPoX socket
family. Data is 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.
Signed-off-by: James Chapman <jchapman@...alix.com>
Index: linux-2.6.21-rc7/drivers/net/pppol2tp.c
===================================================================
--- /dev/null
+++ linux-2.6.21-rc7/drivers/net/pppol2tp.c
@@ -0,0 +1,2582 @@
+/*****************************************************************************
+ * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets
+ *
+ * PPPoX --- Generic PPP encapsulation socket family
+ * PPPoL2TP --- PPP over L2TP (RFC 2661)
+ *
+ * Version: 0.16.0
+ *
+ * Authors: Martijn van Oosterhout <kleptog@...na.org>
+ * James Chapman (jchapman@...alix.com)
+ * Contributors:
+ * Michal Ostrowski <mostrows@...akeasy.net>
+ * Arnaldo Carvalho de Melo <acme@...nectiva.com.br>
+ * David S. Miller (davem@...hat.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.pid = 0; // current pid owns 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/version.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/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 "V0.16"
+
+/* 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_data_ready)(struct sock *, int);
+ 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;
+
+ session = (struct pppol2tp_session *)(sk->sk_user_data);
+ if (session == NULL)
+ return NULL;
+
+ BUG_ON(session->magic != L2TP_SESSION_MAGIC);
+
+ return session;
+}
+
+static inline struct pppol2tp_tunnel *pppol2tp_sock_to_tunnel(struct sock *sk)
+{
+ struct pppol2tp_tunnel *tunnel;
+
+ if (sk == NULL)
+ return NULL;
+
+ tunnel = (struct pppol2tp_tunnel *)(sk->sk_user_data);
+ if (tunnel == NULL)
+ return NULL;
+
+ BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC);
+
+ 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(&tunnel->hlist_lock);
+ return session;
+ }
+ }
+ read_unlock_bh(&tunnel->hlist_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;
+ u16 ns = PPPOL2TP_SKB_CB(skb)->ns;
+
+ spin_lock(&session->reorder_q.lock);
+ skb_queue_walk(&session->reorder_q, skbp) {
+ if (PPPOL2TP_SKB_CB(skbp)->ns > ns) {
+ __skb_insert(skb, skbp->prev, skbp, &session->reorder_q);
+ 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(&session->reorder_q.lock);
+}
+
+/* Dequeue a single skb, passing it either to ppp or to userspace.
+ */
+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 unlink it and return resources
+ * to its current owner (a socket receive buffer).
+ */
+ skb_unlink(skb, &session->reorder_q);
+ 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. Queue it now */
+ if (sock_queue_rcv_skb(session_sock, skb) < 0) {
+ session->stats.rx_errors++;
+ kfree_skb(skb);
+ if (!sock_flag(session_sock, SOCK_DEAD))
+ session_sock->sk_data_ready(session_sock, 0);
+ }
+ }
+
+ 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(&session->reorder_q.lock);
+ skb_queue_walk_safe(&session->reorder_q, skb, tmp) {
+ spin_unlock(&session->reorder_q.lock);
+
+ 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);
+ goto again;
+ }
+
+ 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;
+ }
+ }
+ pppol2tp_recv_dequeue_skb(session, skb);
+again:
+ spin_lock(&session->reorder_q.lock);
+ }
+
+ spin_unlock(&session->reorder_q.lock);
+out:
+ return;
+}
+
+/* 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;
+ u16 hdrflags;
+ u16 tunnel_id, session_id;
+ int length;
+
+ tunnel = pppol2tp_sock_to_tunnel(sock);
+ if (tunnel == NULL)
+ goto error;
+
+ /* Short packet? */
+ if (skb->len < sizeof(struct udphdr)) {
+ 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 */
+ ptr = skb->data + sizeof(struct udphdr);
+
+ /* Get L2TP header flags */
+ hdrflags = ntohs(*(u16*)ptr);
+
+ /* Trace packet contents, if enabled */
+ if (tunnel->debug & PPPOL2TP_MSG_DATA) {
+ printk(KERN_DEBUG "%s: recv: ", tunnel->name);
+
+ for (length = 0; length < 16; length++)
+ printk(" %02X", ptr[length]);
+ printk("\n");
+ }
+
+ /* Get length of L2TP packet */
+ length = ntohs(skb->h.uh->len) - sizeof(struct udphdr);
+
+ /* Too short? */
+ if (length < 12) {
+ PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_INFO,
+ "%s: recv short L2TP packet (len=%d)\n", tunnel->name, length);
+ goto error;
+ }
+
+ /* 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(*(u16 *) ptr);
+ ptr += 2;
+ session_id = ntohs(*(u16 *) 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(*(u16 *) ptr);
+ ptr += 2;
+ nr = ntohs(*(u16 *) 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++;
+ session->stats.rx_errors++;
+ 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++;
+ session->stats.rx_errors++;
+ 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)
+ ptr += 2 + ntohs(*(u16 *) ptr);
+
+ skb_pull(skb, ptr - skb->data);
+
+ /* 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 ((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++;
+ session->stats.rx_errors++;
+ 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:
+ kfree_skb(skb);
+ sock_put(session->sock);
+
+ return 0;
+
+error:
+ return 1;
+}
+
+/* The data_ready hook on the UDP socket. Scan the incoming packet list for
+ * packets to process. Only control or bad data packets are delivered to
+ * userspace.
+ */
+static void pppol2tp_data_ready(struct sock *sk, int len)
+{
+ struct pppol2tp_tunnel *tunnel;
+ struct sk_buff *skb;
+
+ tunnel = pppol2tp_sock_to_tunnel(sk);
+ if (tunnel == NULL)
+ goto end;
+
+ PRINTK(tunnel->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
+ "%s: received %d bytes\n", tunnel->name, len);
+
+ skb = skb_dequeue(&sk->sk_receive_queue);
+ if (skb != NULL) {
+ if (pppol2tp_recv_core(sk, skb)) {
+ skb_queue_head(&sk->sk_receive_queue, skb);
+ tunnel->old_data_ready(sk, len);
+ }
+ }
+end:
+ return;
+}
+
+/* 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) {
+ err = memcpy_toiovec(msg->msg_iov, (unsigned char *) skb->data,
+ skb->len);
+ if (err < 0)
+ goto do_skb_free;
+ err = skb->len;
+ }
+do_skb_free:
+ 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;
+
+ 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;
+
+ /* 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;
+
+ /* Reserve space for headers. */
+ skb_reserve(skb, NET_SKB_PAD);
+ skb->nh.raw = skb->data;
+ skb_reserve(skb, sizeof(struct iphdr));
+ skb->h.raw = skb->data;
+
+ /* Build UDP header */
+ inet = inet_sk(session->tunnel_sock);
+ skb->h.uh->source = inet->sport;
+ skb->h.uh->dest = inet->dport;
+ skb->h.uh->len = htons(hdr_len + sizeof(ppph) + total_len);
+ skb->h.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;
+ }
+ 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 %d bytes, ns=%hu\n", session->name,
+ total_len, session->ns - 1);
+ else
+ PRINTK(session->debug, PPPOL2TP_MSG_DATA, KERN_DEBUG,
+ "%s: send %d 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 */
+ error = ip_queue_xmit(skb, 1);
+
+ /* Update stats */
+ if (error >= 0) {
+ tunnel->stats.tx_packets++;
+ tunnel->stats.tx_bytes += skb->len;
+ session->stats.tx_packets++;
+ session->stats.tx_bytes += skb->len;
+ } else {
+ tunnel->stats.tx_errors++;
+ session->stats.tx_errors++;
+ }
+
+error:
+ return error;
+}
+
+/* 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 sk_buff *skb2 = NULL;
+
+ 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;
+ tunnel = pppol2tp_sock_to_tunnel(sk_tun);
+ if (tunnel == NULL)
+ goto abort;
+
+ /* 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. Note that a new skb (or a clone) is
+ * allocated. If we return an error from this point on, make
+ * sure we free the new skb but do not free the original skb
+ * since that is done by the caller for the error case.
+ */
+ headroom = NET_SKB_PAD + sizeof(struct iphdr) +
+ sizeof(struct udphdr) + hdr_len + sizeof(ppph);
+ if (skb_headroom(skb) < headroom) {
+ skb2 = skb_realloc_headroom(skb, headroom);
+ if (skb2 == NULL)
+ goto abort;
+ } else
+ skb2 = skb;
+
+ /* Check that the socket has room */
+ if (atomic_read(&sk_tun->sk_wmem_alloc) < sk_tun->sk_sndbuf)
+ skb_set_owner_w(skb2, sk_tun);
+ else
+ goto discard;
+
+ /* Setup PPP header */
+ skb_push(skb2, sizeof(ppph));
+ skb2->data[0] = ppph[0];
+ skb2->data[1] = ppph[1];
+
+ /* Setup L2TP header */
+ skb_push(skb2, hdr_len);
+ pppol2tp_build_l2tp_header(session, skb2->data);
+
+ /* Setup UDP header */
+ inet = inet_sk(sk_tun);
+ skb_push(skb2, sizeof(struct udphdr));
+ skb2->h.raw = skb2->data;
+ skb2->h.uh->source = inet->sport;
+ skb2->h.uh->dest = inet->dport;
+ skb2->h.uh->len = htons(sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_len);
+ skb2->h.uh->check = 0;
+
+ /* Calculate UDP checksum if configured to do so */
+ if (sk_tun->sk_no_check != UDP_CSUM_NOXMIT)
+ csum = udp_csum_outgoing(sk_tun, skb2);
+
+ /* 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 = skb2->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");
+ }
+
+ /* Get routing info from the tunnel socket */
+ skb2->dst = sk_dst_get(sk_tun);
+
+ /* Queue the packet to IP for output */
+ rc = ip_queue_xmit(skb2, 1);
+
+ /* Update stats */
+ if (rc >= 0) {
+ tunnel->stats.tx_packets++;
+ tunnel->stats.tx_bytes += skb2->len;
+ session->stats.tx_packets++;
+ session->stats.tx_bytes += skb2->len;
+ } else {
+ tunnel->stats.tx_errors++;
+ session->stats.tx_errors++;
+ }
+
+ /* Free the original skb */
+ kfree_skb(skb);
+
+ return 1;
+
+discard:
+ /* Free the new skb. Caller will free original skb. */
+ if (skb2 != skb)
+ kfree_skb(skb2);
+abort:
+ return 0;
+}
+
+/*****************************************************************************
+ * 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]) {
+ 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);
+ skb_queue_purge(&session->reorder_q);
+
+ 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 = pppol2tp_sock_to_tunnel(sk);
+ 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);
+
+ /* Remove hooks into tunnel socket */
+ tunnel->sock = NULL;
+ sk->sk_data_ready = tunnel->old_data_ready;
+ 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 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 = pppol2tp_sock_to_session(sk);
+ if (session == NULL)
+ goto out;
+
+ /* 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. See
+ * pppol2tp_prepare_tunnel_socket().
+ */
+ 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;
+ 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;
+
+ /* Purge any queued data */
+ skb_queue_purge(&sk->sk_receive_queue);
+ skb_queue_purge(&sk->sk_write_queue);
+
+ 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;
+}
+
+/* Copied from fget() in fs/file_table.c.
+ * Allows caller to specify the pid that owns the fd.
+ */
+static struct file *pppol2tp_fget(pid_t pid, unsigned int fd)
+{
+ struct file *file;
+ struct files_struct *files = current->files;
+
+ if (pid != 0) {
+ struct task_struct *tsk = find_task_by_pid(pid);
+ if (tsk == NULL)
+ return NULL;
+ files = tsk->files;
+ }
+
+ spin_lock(&files->file_lock);
+ file = fcheck_files(files, fd);
+ if (file)
+ get_file(file);
+ spin_unlock(&files->file_lock);
+ return file;
+}
+
+/* Copied from sockfd_lookup() in net/socket.c.
+ * Allows caller to specify the pid that owns the fd. This is needed
+ * to support separate userspace daemons for L2TP and PPP where the
+ * PPPoX socket is created by pppd and must be bound to the tunnel UDP
+ * socket created by l2tpd. The L2TP daemon passes the fd number to
+ * pppd but in order for the PPPoX socket to reference the UDP socket
+ * within the kernel, it needs to be able to lookup the fd of another
+ * process, hence this code.
+ */
+static struct socket *pppol2tp_sockfd_lookup(pid_t pid, int fd, int *err)
+{
+ struct file *file;
+ struct inode *inode;
+ struct socket *sock;
+
+ if (!(file = pppol2tp_fget(pid, fd))) {
+ *err = -EBADF;
+ return NULL;
+ }
+
+ inode = file->f_dentry->d_inode;
+ if (!(sock = SOCKET_I(inode))) {
+ *err = -ENOTSOCK;
+ fput(file);
+ return NULL;
+ }
+
+ if (sock->file != file) {
+ sock->file = file;
+ }
+ return sock;
+}
+
+/* Internal function to prepare a tunnel (UDP) socket to have PPPoX
+ * sockets attached to it
+ */
+static struct sock *pppol2tp_prepare_tunnel_socket(pid_t pid, 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 and passed to pppd. Since we're
+ * being called in the context of pppd here, we need to find
+ * the fd in the context of another process, hence the
+ * pppol2tp_sockfd_lookup code.
+ */
+ err = -EBADF;
+ sock = pppol2tp_sockfd_lookup(pid, 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;
+ }
+
+ /* Quick sanity checks */
+ err = -ESOCKTNOSUPPORT;
+ if (sock->type != SOCK_DGRAM) {
+ PRINTK(-1, PPPOL2TP_MSG_CONTROL, KERN_ERR,
+ "tunl %hu: fd %d wrong type, got %d, expected %d\n",
+ tunnel_id, fd, sock->type, SOCK_DGRAM);
+ 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;
+ sk = sock->sk;
+
+ /* 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;
+
+ /* Setup the new protocol stuff */
+ tunnel->old_data_ready = sk->sk_data_ready;
+ sk->sk_data_ready = &pppol2tp_data_ready;
+
+ 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);
+
+ 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 socket *sock)
+{
+ int error = -ENOMEM;
+ struct sock *sk;
+
+ sk = sk_alloc(PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, 1);
+ 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;
+
+ /* Look up the tunnel socket and configure it if necessary */
+ tunnel_sock = pppol2tp_prepare_tunnel_socket(sp->pppol2tp.pid,
+ sp->pppol2tp.fd,
+ sp->pppol2tp.s_tunnel,
+ &error);
+ if (tunnel_sock == NULL)
+ goto end;
+
+ tunnel = tunnel_sock->sk_user_data;
+
+ /* 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);
+
+ session->debug = PPPOL2TP_DEFAULT_DEBUG_FLAGS;
+
+ /* 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;
+
+ /* 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:
+ release_sock(sk);
+
+ if (error != 0)
+ PRINTK(session ? session->debug : -1, PPPOL2TP_MSG_CONTROL, KERN_WARNING,
+ "%s: connect failed: %d\n", session->name, 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;
+
+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;
+
+ err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg);
+ goto end;
+ }
+
+ err = pppol2tp_session_ioctl(session, cmd, arg);
+
+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;
+
+ lock_sock(sk);
+
+ 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;
+
+ err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val);
+ } else
+ err = pppol2tp_session_setsockopt(sk, session, optname, val);
+
+ err = 0;
+
+end:
+ release_sock(sk);
+ return err;
+}
+
+/* Tunnel getsockopt helper. Called with sock locked.
+ */
+static int pppol2tp_tunnel_getsockopt(struct sock *sk,
+ struct pppol2tp_tunnel *tunnel,
+ int optname, int __user *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 __user *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;
+
+ lock_sock(sk);
+
+ 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;
+
+ err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val);
+ } else
+ err = pppol2tp_session_getsockopt(sk, session, optname, &val);
+
+ err = -EFAULT;
+ if (put_user(len, (int __user *) optlen))
+ goto end;
+
+ if (copy_to_user((void __user *) optval, &val, len))
+ goto end;
+
+ err = 0;
+end:
+ release_sock(sk);
+ return err;
+}
+
+/*****************************************************************************
+ * /proc filesystem for debug
+ *****************************************************************************/
+
+#ifdef CONFIG_PROC_FS
+
+#include <linux/seq_file.h>
+
+/* We make an array of these structures, one per tunnel or session,
+ * and sort them, for use by the seq iterator. When outputting text
+ * for each tunnel or session, we index into this structure and find
+ * the context using the stored ids. The array is freed when the seq
+ * file operation completes.
+ */
+struct pppol2tp_seq_data {
+ u16 tunnel_id;
+ u16 session_id; /* is zero for tunnels */
+};
+
+static int pppol2tp_proc_open(struct inode *inode, struct file *file);
+static int pppol2tp_proc_release(struct inode *inode, struct file *file);
+static void *pppol2tp_seq_start(struct seq_file *m, loff_t *_pos);
+static void *pppol2tp_seq_next(struct seq_file *p, void *v, loff_t *pos);
+static void pppol2tp_seq_stop(struct seq_file *p, void *v);
+static int pppol2tp_seq_show(struct seq_file *m, void *v);
+
+static struct proc_dir_entry *pppol2tp_proc;
+
+static struct seq_operations pppol2tp_seq_ops = {
+ .start = pppol2tp_seq_start,
+ .next = pppol2tp_seq_next,
+ .stop = pppol2tp_seq_stop,
+ .show = pppol2tp_seq_show,
+};
+
+static struct file_operations pppol2tp_proc_fops = {
+ .owner = THIS_MODULE,
+ .open = pppol2tp_proc_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = pppol2tp_proc_release,
+};
+
+/* Used by sort()
+ */
+static void pppol2tp_seq_swap(void *a, void *b, int size)
+{
+ struct pppol2tp_seq_data tmp;
+ struct pppol2tp_seq_data *left = a;
+ struct pppol2tp_seq_data *right = b;
+
+ tmp = *left;
+ *left = *right;
+ *right = tmp;
+}
+
+/* Used by sort()
+ */
+static int pppol2tp_seq_cmp(const void *a, const void *b)
+{
+ const struct pppol2tp_seq_data *left = a;
+ const struct pppol2tp_seq_data *right = b;
+
+ if (left->tunnel_id < right->tunnel_id)
+ return -1;
+ if (left->tunnel_id > right->tunnel_id)
+ return 1;
+ if (left->session_id < right->session_id)
+ return -1;
+ if (left->session_id > right->session_id)
+ return 1;
+ return 0;
+}
+
+/* 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 pppol2tp_tunnel *tunnel;
+ struct pppol2tp_session *session;
+ struct hlist_node *walk;
+ int i;
+ int contexts = atomic_read(&pppol2tp_tunnel_count) +
+ atomic_read(&pppol2tp_session_count) + 1;
+ int count = 0;
+ 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 = kmalloc(contexts * sizeof(struct pppol2tp_seq_data), GFP_KERNEL);
+ if (m->private == NULL)
+ goto out;
+
+ pd = m->private;
+ read_lock_bh(&pppol2tp_tunnel_list_lock);
+ list_for_each_entry(tunnel, &pppol2tp_tunnel_list, list) {
+ if (count >= (contexts - 1))
+ break;
+ pd->tunnel_id = tunnel->stats.tunnel_id;
+ pd->session_id = 0;
+ pd++;
+ count++;
+ for (i = 0; i < PPPOL2TP_HASH_SIZE; i++) {
+ hlist_for_each_entry(session, walk, &tunnel->session_hlist[i], hlist) {
+ if (count >= (contexts - 1))
+ break;
+ pd->tunnel_id = tunnel->stats.tunnel_id;
+ pd->session_id = session->tunnel_addr.s_session;
+ pd++;
+ count++;
+ }
+ }
+ }
+
+ /* Add end marker */
+ pd->tunnel_id = 0;
+ pd->session_id = 0;
+
+ read_unlock_bh(&pppol2tp_tunnel_list_lock);
+
+ /* Sort the array by tunnel_id/session_id since we use
+ * hashed lists
+ */
+ sort(m->private, count, sizeof(struct pppol2tp_seq_data),
+ pppol2tp_seq_cmp, pppol2tp_seq_swap);
+
+ 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 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;
+
+ /* Turn pos into an index */
+ pos--;
+
+ /* return the n'th element in the sorted array */
+ BUG_ON(m->private == NULL);
+ pd = m->private;
+ pd += pos;
+
+ /* tunnel_id zero indicates end of list */
+ if (pd->tunnel_id == 0) {
+ pd = NULL;
+ goto out;
+ }
+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 MAGIC %s\n",
+ tunnel->name,
+ (tunnel == tunnel->sock->sk_user_data) ? 'Y':'N',
+ atomic_read(&tunnel->ref_count) - 1,
+ (tunnel->magic == L2TP_TUNNEL_MAGIC) ? "OK" : "BAD");
+ seq_printf(m, " %08x %llu/%llu/%llu %llu/%llu/%llu\n",
+ tunnel->debug,
+ tunnel->stats.tx_packets, tunnel->stats.tx_bytes,
+ tunnel->stats.tx_errors,
+ tunnel->stats.rx_packets, tunnel->stats.rx_bytes,
+ 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 MAGIC %s\n",
+ session->name,
+ htonl(session->tunnel_addr.addr.sin_addr.s_addr),
+ htons(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',
+ (session->magic == L2TP_SESSION_MAGIC) ?
+ "OK" : "BAD");
+
+ 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,
+ session->stats.tx_packets,
+ session->stats.tx_bytes,
+ session->stats.tx_errors,
+ session->stats.rx_packets,
+ session->stats.rx_bytes,
+ session->stats.rx_errors);
+}
+
+/* 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;
+}
+
+static int pppol2tp_seq_show(struct seq_file *m, void *v)
+{
+ struct pppol2tp_seq_data *pd = v;
+ struct pppol2tp_tunnel *tunnel;
+ struct pppol2tp_session *session;
+
+ /* 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 magic-ok\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 magic-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 using the tunnel_id /
+ * session_id pair. A session_id of zero indicates a
+ * tunnel. If the context can't be found, it was removed while
+ * dumping this info. Silently ignore it and move to the next
+ * one.
+ */
+ tunnel = pppol2tp_tunnel_find(pd->tunnel_id);
+ if (tunnel != NULL) {
+ if (pd->session_id == 0)
+ pppol2tp_seq_tunnel_show(m, tunnel);
+ else {
+ session = pppol2tp_session_find(tunnel, pd->session_id);
+ if (session != NULL)
+ pppol2tp_seq_session_show(m, session);
+ }
+ }
+
+out:
+ return 0;
+}
+
+#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 = create_proc_entry("pppol2tp", 0, proc_net);
+ if (!pppol2tp_proc) {
+ err = -ENOMEM;
+ goto out_unregister_pppox_proto;
+ }
+ pppol2tp_proc->proc_fops = &pppol2tp_proc_fops;
+#endif /* CONFIG_PROC_FS */
+ printk(KERN_INFO "PPPoL2TP kernel driver, %s\n",
+ PPPOL2TP_DRV_VERSION);
+
+out:
+ return err;
+
+out_unregister_pppox_proto:
+ unregister_pppox_proto(PX_PROTO_OL2TP);
+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", proc_net);
+#endif
+ proto_unregister(&pppol2tp_sk_proto);
+}
+
+module_init(pppol2tp_init);
+module_exit(pppol2tp_exit);
+
+MODULE_AUTHOR("Martijn van Oosterhout <kleptog@...na.org>");
+MODULE_AUTHOR("James Chapman <jchapman@...alix.com>");
+MODULE_DESCRIPTION("PPP over L2TP over UDP");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(PPPOL2TP_DRV_VERSION);
Index: linux-2.6.21-rc7/include/linux/if_pppol2tp.h
===================================================================
--- /dev/null
+++ linux-2.6.21-rc7/include/linux/if_pppol2tp.h
@@ -0,0 +1,67 @@
+/***************************************************************************
+ * Linux PPP over L2TP (PPPoL2TP) Socket Implementation (RFC 2661)
+ *
+ * This file supplies definitions required by the PPP over L2TP driver
+ * (pppol2tp.c). All version information wrt this file is located in pppol2tp.c
+ *
+ * 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.
+ *
+ */
+
+#ifndef __LINUX_IF_PPPOL2TP_H
+#define __LINUX_IF_PPPOL2TP_H
+
+#include <asm/types.h>
+
+#ifdef __KERNEL__
+#include <linux/in.h>
+#endif
+
+/* Structure used to bind() the socket to a particular socket & tunnel */
+struct pppol2tp_addr
+{
+ pid_t pid; /* pid that owns the fd.
+ * 0 => current */
+ int fd; /* FD of UDP socket to use */
+
+ struct sockaddr_in addr; /* IP address and port to send to */
+
+ __be16 s_tunnel, s_session; /* For matching incoming packets */
+ __be16 d_tunnel, d_session; /* For sending outgoing packets */
+};
+
+/* Socket options:
+ * DEBUG - bitmask of debug message categories
+ * SENDSEQ - 0 => don't send packets with sequence numbers
+ * 1 => send packets with sequence numbers
+ * RECVSEQ - 0 => receive packet sequence numbers are optional
+ * 1 => drop receive packets without sequence numbers
+ * LNSMODE - 0 => act as LAC.
+ * 1 => act as LNS.
+ * REORDERTO - reorder timeout (in millisecs). If 0, don't try to reorder.
+ */
+enum {
+ PPPOL2TP_SO_DEBUG = 1,
+ PPPOL2TP_SO_RECVSEQ = 2,
+ PPPOL2TP_SO_SENDSEQ = 3,
+ PPPOL2TP_SO_LNSMODE = 4,
+ PPPOL2TP_SO_REORDERTO = 5,
+};
+
+/* Debug message categories for the DEBUG socket option */
+enum {
+ PPPOL2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if
+ * compiled in) */
+ PPPOL2TP_MSG_CONTROL = (1 << 1), /* userspace - kernel
+ * interface */
+ PPPOL2TP_MSG_SEQ = (1 << 2), /* sequence numbers */
+ PPPOL2TP_MSG_DATA = (1 << 3), /* data packets */
+};
+
+
+
+#endif
Index: linux-2.6.21-rc7/drivers/net/Kconfig
===================================================================
--- linux-2.6.21-rc7.orig/drivers/net/Kconfig
+++ linux-2.6.21-rc7/drivers/net/Kconfig
@@ -2813,6 +2813,19 @@ config PPPOATM
which can lead to bad results if the ATM peer loses state and
changes its encapsulation unilaterally.
+config PPPOL2TP
+ tristate "PPP over L2TP (EXPERIMENTAL)"
+ depends on EXPERIMENTAL && PPP
+ help
+ Support for PPP-over-L2TP socket family. L2TP is a protocol
+ used by ISPs and enterprises to tunnel PPP traffic over UDP
+ tunnels. L2TP is replacing PPTP for VPN uses.
+
+ This kernel component handles only L2TP data packets: a
+ userland daemon handles L2TP the control protocol (tunnel
+ and session setup). One such daemon is OpenL2TP
+ (http://openl2tp.sourceforge.net/).
+
config SLIP
tristate "SLIP (serial line) support"
---help---
Index: linux-2.6.21-rc7/drivers/net/Makefile
===================================================================
--- linux-2.6.21-rc7.orig/drivers/net/Makefile
+++ linux-2.6.21-rc7/drivers/net/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_PPP_DEFLATE) += ppp_deflate
obj-$(CONFIG_PPP_BSDCOMP) += bsd_comp.o
obj-$(CONFIG_PPP_MPPE) += ppp_mppe.o
obj-$(CONFIG_PPPOE) += pppox.o pppoe.o
+obj-$(CONFIG_PPPOL2TP) += pppox.o pppol2tp.o
obj-$(CONFIG_SLIP) += slip.o
obj-$(CONFIG_SLHC) += slhc.o
Index: linux-2.6.21-rc7/include/linux/Kbuild
===================================================================
--- linux-2.6.21-rc7.orig/include/linux/Kbuild
+++ linux-2.6.21-rc7/include/linux/Kbuild
@@ -220,6 +220,7 @@ unifdef-y += if_fddi.h
unifdef-y += if_frad.h
unifdef-y += if_ltalk.h
unifdef-y += if_link.h
+unifdef-y += if_pppol2tp.h
unifdef-y += if_pppox.h
unifdef-y += if_shaper.h
unifdef-y += if_tr.h
-
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