Commit f7faffa3 authored by James Chapman's avatar James Chapman Committed by David S. Miller

l2tp: Add L2TPv3 protocol support

The L2TPv3 protocol changes the layout of the L2TP packet
header. Tunnel and session ids change from 16-bit to 32-bit values,
data sequence numbers change from 16-bit to 24-bit values and PPP-specific
fields are moved into protocol-specific subheaders.

Although this patch introduces L2TPv3 protocol support, there are no
userspace interfaces to create L2TPv3 sessions yet.
Signed-off-by: default avatarJames Chapman <jchapman@katalix.com>
Reviewed-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9345471b
......@@ -19,6 +19,10 @@ menuconfig L2TP
connections. L2TP is also used as a VPN protocol, popular
with home workers to connect to their offices.
L2TPv3 allows other protocols as well as PPP to be carried
over L2TP tunnels. L2TPv3 is defined in RFC 3931
<http://www.ietf.org/rfc/rfc3931.txt>.
The kernel component handles only L2TP data packets: a
userland daemon handles L2TP the control protocol (tunnel
and session setup). One such daemon is OpenL2TP
......@@ -26,3 +30,24 @@ menuconfig L2TP
If you don't need L2TP, say N. To compile all L2TP code as
modules, choose M here.
config L2TP_V3
bool "L2TPv3 support (EXPERIMENTAL)"
depends on EXPERIMENTAL && L2TP
help
Layer Two Tunneling Protocol Version 3
From RFC 3931 <http://www.ietf.org/rfc/rfc3931.txt>.
The Layer Two Tunneling Protocol (L2TP) provides a dynamic
mechanism for tunneling Layer 2 (L2) "circuits" across a
packet-oriented data network (e.g., over IP). L2TP, as
originally defined in RFC 2661, is a standard method for
tunneling Point-to-Point Protocol (PPP) [RFC1661] sessions.
L2TP has since been adopted for tunneling a number of other
L2 protocols, including ATM, Frame Relay, HDLC and even raw
ethernet frames.
If you are connecting to L2TPv3 equipment, or you want to
tunnel raw ethernet frames using L2TP, say Y here. If
unsure, say N.
This diff is collapsed.
......@@ -15,9 +15,14 @@
#define L2TP_TUNNEL_MAGIC 0x42114DDA
#define L2TP_SESSION_MAGIC 0x0C04EB7D
/* Per tunnel, session hash table size */
#define L2TP_HASH_BITS 4
#define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS)
/* System-wide, session hash table size */
#define L2TP_HASH_BITS_2 8
#define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2)
/* Debug message categories for the DEBUG socket option */
enum {
L2TP_MSG_DEBUG = (1 << 0), /* verbose debug (if
......@@ -28,6 +33,21 @@ enum {
L2TP_MSG_DATA = (1 << 3), /* data packets */
};
enum l2tp_pwtype {
L2TP_PWTYPE_NONE = 0x0000,
L2TP_PWTYPE_ETH_VLAN = 0x0004,
L2TP_PWTYPE_ETH = 0x0005,
L2TP_PWTYPE_PPP = 0x0007,
L2TP_PWTYPE_PPP_AC = 0x0008,
L2TP_PWTYPE_IP = 0x000b,
__L2TP_PWTYPE_MAX
};
enum l2tp_l2spec_type {
L2TP_L2SPECTYPE_NONE,
L2TP_L2SPECTYPE_DEFAULT,
};
struct sk_buff;
struct l2tp_stats {
......@@ -39,6 +59,7 @@ struct l2tp_stats {
u64 rx_seq_discards;
u64 rx_oos_packets;
u64 rx_errors;
u64 rx_cookie_discards;
};
struct l2tp_tunnel;
......@@ -47,6 +68,7 @@ struct l2tp_tunnel;
* packets and transmit outgoing ones.
*/
struct l2tp_session_cfg {
enum l2tp_pwtype pw_type;
unsigned data_seq:2; /* data sequencing level
* 0 => none, 1 => IP only,
* 2 => all
......@@ -60,12 +82,17 @@ struct l2tp_session_cfg {
* control of LNS. */
int debug; /* bitmask of debug message
* categories */
int offset; /* offset to payload */
u16 offset; /* offset to payload */
u16 l2specific_len; /* Layer 2 specific length */
u16 l2specific_type; /* Layer 2 specific type */
u8 cookie[8]; /* optional cookie */
int cookie_len; /* 0, 4 or 8 bytes */
u8 peer_cookie[8]; /* peer's cookie */
int peer_cookie_len; /* 0, 4 or 8 bytes */
int reorder_timeout; /* configured reorder timeout
* (in jiffies) */
int mtu;
int mru;
int hdr_len;
};
struct l2tp_session {
......@@ -76,8 +103,17 @@ struct l2tp_session {
* context */
u32 session_id;
u32 peer_session_id;
u16 nr; /* session NR state (receive) */
u16 ns; /* session NR state (send) */
u8 cookie[8];
int cookie_len;
u8 peer_cookie[8];
int peer_cookie_len;
u16 offset; /* offset from end of L2TP header
to beginning of data */
u16 l2specific_len;
u16 l2specific_type;
u16 hdr_len;
u32 nr; /* session NR state (receive) */
u32 ns; /* session NR state (send) */
struct sk_buff_head reorder_q; /* receive reorder queue */
struct hlist_node hlist; /* Hash list node */
atomic_t ref_count;
......@@ -100,9 +136,11 @@ struct l2tp_session {
* (in jiffies) */
int mtu;
int mru;
int hdr_len;
enum l2tp_pwtype pwtype;
struct l2tp_stats stats;
struct hlist_node global_hlist; /* Global hash list node */
int (*build_header)(struct l2tp_session *session, void *buf);
void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len);
void (*session_close)(struct l2tp_session *session);
void (*ref)(struct l2tp_session *session);
......@@ -132,7 +170,6 @@ struct l2tp_tunnel {
char name[20]; /* for logging */
int debug; /* bitmask of debug message
* categories */
int hdr_len;
struct l2tp_stats stats;
struct list_head list; /* Keep a list of all tunnels */
......@@ -178,7 +215,7 @@ static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk)
return tunnel;
}
extern struct l2tp_session *l2tp_session_find(struct l2tp_tunnel *tunnel, u32 session_id);
extern struct l2tp_session *l2tp_session_find(struct net *net, struct l2tp_tunnel *tunnel, u32 session_id);
extern struct l2tp_session *l2tp_session_find_nth(struct l2tp_tunnel *tunnel, int nth);
extern struct l2tp_tunnel *l2tp_tunnel_find(struct net *net, u32 tunnel_id);
extern struct l2tp_tunnel *l2tp_tunnel_find_nth(struct net *net, int nth);
......@@ -187,14 +224,15 @@ extern int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_i
extern struct l2tp_session *l2tp_session_create(int priv_size, struct l2tp_tunnel *tunnel, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg);
extern void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
extern void l2tp_session_free(struct l2tp_session *session);
extern void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, unsigned char *ptr, unsigned char *optr, u16 hdrflags, int length, int (*payload_hook)(struct sk_buff *skb));
extern int l2tp_udp_recv_core(struct l2tp_tunnel *tunnel, struct sk_buff *skb, int (*payload_hook)(struct sk_buff *skb));
extern int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb);
extern void l2tp_build_l2tp_header(struct l2tp_session *session, void *buf);
extern int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t data_len);
extern int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len);
extern void l2tp_tunnel_destruct(struct sock *sk);
extern void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel);
extern void l2tp_session_set_header_len(struct l2tp_session *session, int version);
/* Tunnel reference counts. Incremented per session that is added to
* the tunnel.
......
......@@ -670,7 +670,7 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
/* Check that this session doesn't already exist */
error = -EEXIST;
session = l2tp_session_find(tunnel, sp->pppol2tp.s_session);
session = l2tp_session_find(sock_net(sk), tunnel, sp->pppol2tp.s_session);
if (session != NULL)
goto end;
......@@ -678,7 +678,6 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr,
* headers.
*/
cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD;
cfg.hdr_len = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ;
cfg.debug = tunnel->debug;
/* Allocate and initialize a new session context. */
......@@ -999,7 +998,7 @@ static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel,
if (stats.session_id != 0) {
/* resend to session ioctl handler */
struct l2tp_session *session =
l2tp_session_find(tunnel, stats.session_id);
l2tp_session_find(sock_net(sk), tunnel, stats.session_id);
if (session != NULL)
err = pppol2tp_session_ioctl(session, cmd, arg);
else
......@@ -1375,6 +1374,8 @@ static int pppol2tp_getsockopt(struct socket *sock, int level,
/*****************************************************************************
* /proc filesystem for debug
* Since the original pppol2tp driver provided /proc/net/pppol2tp for
* L2TPv2, we dump only L2TPv2 tunnels and sessions here.
*****************************************************************************/
static unsigned int pppol2tp_net_id;
......@@ -1391,14 +1392,24 @@ struct pppol2tp_seq_data {
static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
{
pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
pd->tunnel_idx++;
for (;;) {
pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
pd->tunnel_idx++;
if (pd->tunnel == NULL)
break;
/* Ignore L2TPv3 tunnels */
if (pd->tunnel->version < 3)
break;
}
}
static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd)
{
pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
pd->session_idx++;
if (pd->session == NULL) {
pd->session_idx = 0;
pppol2tp_next_tunnel(net, pd);
......
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