/*****************************************************************************
* 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);
}
static inline int pppol2tp_verify_udp_checksum(struct sock *sk,
struct sk_buff *skb)
{
struct udphdr *uh = udp_hdr(skb);
u16 ulen = ntohs(uh->len);
struct inet_sock *inet;
__wsum psum;
if (sk->sk_no_check || skb_csum_unnecessary(skb) || !uh->check)
return 0;
inet = inet_sk(sk);
psum = csum_tcpudp_nofold(inet->saddr, inet->daddr, ulen,
IPPROTO_UDP, 0);
if ((skb->ip_summed == CHECKSUM_COMPLETE) &&
!csum_fold(csum_add(psum, skb->csum)))
return 0;
skb->csum = psum;
return __skb_checksum_complete(skb);
}
/* 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;
if (tunnel->sock && pppol2tp_verify_udp_checksum(tunnel->sock, skb))
goto discard_bad_csum;
/* 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;
discard_bad_csum:
LIMIT_NETDEBUG("%s: UDP: bad checksum\n", tunnel->name);
UDP_INC_STATS_USER(&init_net, UDP_MIB_INERRORS, 0);
tunnel->stats.rx_errors++;
kfree_skb(skb);
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;
struct sk_buff *skb;
int error;
int hdr_len;
struct pppol2tp_session *session;
struct pppol2tp_tunnel *tunnel;
struct udphdr *uh;
unsigned int len;
struct sock *sk_tun;
u16 udp_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;
sk_tun = session->tunnel_sock;
tunnel = pppol2tp_sock_to_tunnel(sk_tun);
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(sk_tun);
udp_len = hdr_len + sizeof(ppph) + total_len;
uh = (struct udphdr *) skb->data;
uh->source = inet->sport;
uh->dest = inet->dport;
uh->len = htons(udp_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 (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
skb->ip_summed = CHECKSUM_NONE;
else if (!(skb->dst->dev->features & NETIF_F_V4_CSUM)) {
skb->ip_summed = CHECKSUM_COMPLETE;
csum = skb_checksum(skb, 0, udp_len, 0);
uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
udp_len, IPPROTO_UDP, csum);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
} else {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
udp_len, IPPROTO_UDP, 0);
}
/* 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;
u16 udp_len;
struct pppol2tp_session *session;
struct pppol2tp_tunnel *tunnel;
int rc;
int headroom;
int data_len = skb->len;
struct inet_sock *inet;
__wsum csum;
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));
udp_len = sizeof(struct udphdr) + hdr_len + sizeof(ppph) + data_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(udp_len);
uh->check = 0;
/* 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);
/* Calculate UDP checksum if configured to do so */
if (sk_tun->sk_no_check == UDP_CSUM_NOXMIT)
skb->ip_summed = CHECKSUM_NONE;
else if (!(skb->dst->dev->features & NETIF_F_V4_CSUM)) {
skb->ip_summed = CHECKSUM_COMPLETE;
csum = skb_checksum(skb, 0, udp_len, 0);
uh->check = csum_tcpudp_magic(inet->saddr, inet->daddr,
udp_len, IPPROTO_UDP, csum);
if (uh->check == 0)
uh->check = CSUM_MANGLED_0;
} else {
skb->ip_summed = CHECKSUM_PARTIAL;
skb->csum_start = skb_transport_header(skb) - skb->head;
skb->csum_offset = offsetof(struct udphdr, check);
uh->check = ~csum_tcpudp_magic(inet->saddr, inet->daddr,
udp_len, IPPROTO_UDP, 0);
}
/* 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);
}
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);
