diff options
| -rw-r--r-- | include/linux/l2tp.h | 38 | ||||
| -rw-r--r-- | net/l2tp/Kconfig | 17 | ||||
| -rw-r--r-- | net/l2tp/Makefile | 1 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.c | 163 | ||||
| -rw-r--r-- | net/l2tp/l2tp_core.h | 7 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ip.c | 679 | ||||
| -rw-r--r-- | net/l2tp/l2tp_ppp.c | 7 |
7 files changed, 850 insertions, 62 deletions
diff --git a/include/linux/l2tp.h b/include/linux/l2tp.h new file mode 100644 index 000000000000..deff7bca4e05 --- /dev/null +++ b/include/linux/l2tp.h @@ -0,0 +1,38 @@ +/* + * L2TP-over-IP socket for L2TPv3. + * + * Author: James Chapman <jchapman@katalix.com> + */ + +#ifndef _LINUX_L2TP_H_ +#define _LINUX_L2TP_H_ + +#include <linux/types.h> +#ifdef __KERNEL__ +#include <linux/socket.h> +#include <linux/in.h> +#endif + +#define IPPROTO_L2TP 115 + +/** + * struct sockaddr_l2tpip - the sockaddr structure for L2TP-over-IP sockets + * @l2tp_family: address family number AF_L2TPIP. + * @l2tp_addr: protocol specific address information + * @l2tp_conn_id: connection id of tunnel + */ +struct sockaddr_l2tpip { + /* The first fields must match struct sockaddr_in */ + sa_family_t l2tp_family; /* AF_INET */ + __be16 l2tp_unused; /* INET port number (unused) */ + struct in_addr l2tp_addr; /* Internet address */ + + __u32 l2tp_conn_id; /* Connection ID of tunnel */ + + /* Pad to size of `struct sockaddr'. */ + unsigned char __pad[sizeof(struct sockaddr) - sizeof(sa_family_t) - + sizeof(__be16) - sizeof(struct in_addr) - + sizeof(__u32)]; +}; + +#endif diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig index d60758d60478..0a11ccf2d95b 100644 --- a/net/l2tp/Kconfig +++ b/net/l2tp/Kconfig @@ -51,3 +51,20 @@ config L2TP_V3 If you are connecting to L2TPv3 equipment, or you want to tunnel raw ethernet frames using L2TP, say Y here. If unsure, say N. + +config L2TP_IP + tristate "L2TP IP encapsulation for L2TPv3" + depends on L2TP_V3 + help + Support for L2TP-over-IP socket family. + + The L2TPv3 protocol defines two possible encapsulations for + L2TP frames, namely UDP and plain IP (without UDP). This + driver provides a new L2TPIP socket family with which + userspace L2TPv3 daemons may create L2TP/IP tunnel sockets + when UDP encapsulation is not required. When L2TP is carried + in IP packets, it used IP protocol number 115, so this port + must be enabled in firewalls. + + To compile this driver as a module, choose M here. The module + will be called l2tp_ip. diff --git a/net/l2tp/Makefile b/net/l2tp/Makefile index c91f208b1693..ef28b16f7d6a 100644 --- a/net/l2tp/Makefile +++ b/net/l2tp/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_L2TP) += l2tp_core.o # Build l2tp as modules if L2TP is M obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip.o diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index 0eee1a65f1b1..1739d04367e4 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -36,8 +36,10 @@ #include <linux/inetdevice.h> #include <linux/skbuff.h> #include <linux/init.h> +#include <linux/in.h> #include <linux/ip.h> #include <linux/udp.h> +#include <linux/l2tp.h> #include <linux/hash.h> #include <linux/sort.h> #include <linux/file.h> @@ -48,6 +50,7 @@ #include <net/ip.h> #include <net/udp.h> #include <net/xfrm.h> +#include <net/protocol.h> #include <asm/byteorder.h> #include <asm/atomic.h> @@ -849,15 +852,21 @@ static int l2tp_build_l2tpv2_header(struct l2tp_session *session, void *buf) static int l2tp_build_l2tpv3_header(struct l2tp_session *session, void *buf) { + struct l2tp_tunnel *tunnel = session->tunnel; char *bufp = buf; char *optr = bufp; - u16 flags = L2TP_HDR_VER_3; - /* Setup L2TP header. */ - *((__be16 *) bufp) = htons(flags); - bufp += 2; - *((__be16 *) bufp) = 0; - bufp += 2; + /* Setup L2TP header. The header differs slightly for UDP and + * IP encapsulations. For UDP, there is 4 bytes of flags. + */ + if (tunnel->encap == L2TP_ENCAPTYPE_UDP) { + u16 flags = L2TP_HDR_VER_3; + *((__be16 *) bufp) = htons(flags); + bufp += 2; + *((__be16 *) bufp) = 0; + bufp += 2; + } + *((__be32 *) bufp) = htonl(session->peer_session_id); bufp += 4; if (session->cookie_len) { @@ -902,10 +911,11 @@ int l2tp_xmit_core(struct l2tp_session *session, struct sk_buff *skb, size_t dat if (session->debug & L2TP_MSG_DATA) { int i; - unsigned char *datap = skb->data + sizeof(struct udphdr); + int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + unsigned char *datap = skb->data + uhlen; printk(KERN_DEBUG "%s: xmit:", session->name); - for (i = 0; i < (len - sizeof(struct udphdr)); i++) { + for (i = 0; i < (len - uhlen); i++) { printk(" %02X", *datap++); if (i == 31) { printk(" ..."); @@ -956,21 +966,23 @@ static inline void l2tp_skb_set_owner_w(struct sk_buff *skb, struct sock *sk) int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len) { int data_len = skb->len; - struct sock *sk = session->tunnel->sock; + struct l2tp_tunnel *tunnel = session->tunnel; + struct sock *sk = tunnel->sock; struct udphdr *uh; - unsigned int udp_len; struct inet_sock *inet; __wsum csum; int old_headroom; int new_headroom; int headroom; + int uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + int udp_len; /* Check that there's enough headroom in the skb to insert IP, * UDP and L2TP headers. If not enough, expand it to * make room. Adjust truesize. */ headroom = NET_SKB_PAD + sizeof(struct iphdr) + - sizeof(struct udphdr) + hdr_len; + uhlen + hdr_len; old_headroom = skb_headroom(skb); if (skb_cow_head(skb, headroom)) goto abort; @@ -981,18 +993,8 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len /* Setup L2TP header */ session->build_header(session, __skb_push(skb, hdr_len)); - udp_len = sizeof(struct udphdr) + hdr_len + data_len; - - /* Setup UDP header */ - inet = inet_sk(sk); - __skb_push(skb, sizeof(*uh)); - skb_reset_transport_header(skb); - uh = udp_hdr(skb); - uh->source = inet->inet_sport; - uh->dest = inet->inet_dport; - uh->len = htons(udp_len); - uh->check = 0; + /* Reset skb netfilter state */ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); @@ -1001,29 +1003,48 @@ int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, int hdr_len /* Get routing info from the tunnel socket */ skb_dst_drop(skb); skb_dst_set(skb, dst_clone(__sk_dst_get(sk))); - l2tp_skb_set_owner_w(skb, sk); - /* Calculate UDP checksum if configured to do so */ - if (sk->sk_no_check == UDP_CSUM_NOXMIT) - skb->ip_summed = CHECKSUM_NONE; - else if ((skb_dst(skb) && skb_dst(skb)->dev) && - (!(skb_dst(skb)->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->inet_saddr, - inet->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->inet_saddr, - inet->inet_daddr, - udp_len, IPPROTO_UDP, 0); + switch (tunnel->encap) { + case L2TP_ENCAPTYPE_UDP: + /* Setup UDP header */ + inet = inet_sk(sk); + __skb_push(skb, sizeof(*uh)); + skb_reset_transport_header(skb); + uh = udp_hdr(skb); + uh->source = inet->inet_sport; + uh->dest = inet->inet_dport; + udp_len = uhlen + hdr_len + data_len; + uh->len = htons(udp_len); + uh->check = 0; + + /* Calculate UDP checksum if configured to do so */ + if (sk->sk_no_check == UDP_CSUM_NOXMIT) + skb->ip_summed = CHECKSUM_NONE; + else if ((skb_dst(skb) && skb_dst(skb)->dev) && + (!(skb_dst(skb)->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->inet_saddr, + inet->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->inet_saddr, + inet->inet_daddr, + udp_len, IPPROTO_UDP, 0); + } + break; + + case L2TP_ENCAPTYPE_IP: + break; } + l2tp_skb_set_owner_w(skb, sk); + l2tp_xmit_core(session, skb, data_len); abort: @@ -1053,9 +1074,15 @@ void l2tp_tunnel_destruct(struct sock *sk) /* Close all sessions */ l2tp_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; + switch (tunnel->encap) { + case L2TP_ENCAPTYPE_UDP: + /* No longer an encapsulation socket. See net/ipv4/udp.c */ + (udp_sk(sk))->encap_type = 0; + (udp_sk(sk))->encap_rcv = NULL; + break; + case L2TP_ENCAPTYPE_IP: + break; + } /* Remove hooks into tunnel socket */ tunnel->sock = NULL; @@ -1168,6 +1195,7 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 struct socket *sock = NULL; struct sock *sk = NULL; struct l2tp_net *pn; + enum l2tp_encap_type encap = L2TP_ENCAPTYPE_UDP; /* Get the tunnel socket from the fd, which was opened by * the userspace L2TP daemon. @@ -1182,18 +1210,27 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 sk = sock->sk; + if (cfg != NULL) + encap = cfg->encap; + /* Quick sanity checks */ - err = -EPROTONOSUPPORT; - if (sk->sk_protocol != IPPROTO_UDP) { - printk(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(KERN_ERR "tunl %hu: fd %d wrong family, got %d, expected %d\n", - tunnel_id, fd, sock->ops->family, AF_INET); - goto err; + switch (encap) { + case L2TP_ENCAPTYPE_UDP: + err = -EPROTONOSUPPORT; + if (sk->sk_protocol != IPPROTO_UDP) { + printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", + tunnel_id, fd, sk->sk_protocol, IPPROTO_UDP); + goto err; + } + break; + case L2TP_ENCAPTYPE_IP: + err = -EPROTONOSUPPORT; + if (sk->sk_protocol != IPPROTO_L2TP) { + printk(KERN_ERR "tunl %hu: fd %d wrong protocol, got %d, expected %d\n", + tunnel_id, fd, sk->sk_protocol, IPPROTO_L2TP); + goto err; + } + break; } /* Check if this socket has already been prepped */ @@ -1223,12 +1260,16 @@ int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, u32 tunnel->l2tp_net = net; pn = l2tp_pernet(net); - if (cfg) + if (cfg != NULL) tunnel->debug = cfg->debug; /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ - udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; - udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; + tunnel->encap = encap; + if (encap == L2TP_ENCAPTYPE_UDP) { + /* Mark socket as an encapsulation socket. See net/ipv4/udp.c */ + udp_sk(sk)->encap_type = UDP_ENCAP_L2TPINUDP; + udp_sk(sk)->encap_rcv = l2tp_udp_encap_recv; + } sk->sk_user_data = tunnel; @@ -1318,7 +1359,9 @@ void l2tp_session_set_header_len(struct l2tp_session *session, int version) if (session->send_seq) session->hdr_len += 4; } else { - session->hdr_len = 8 + session->cookie_len + session->l2specific_len + session->offset; + session->hdr_len = 4 + session->cookie_len + session->l2specific_len + session->offset; + if (session->tunnel->encap == L2TP_ENCAPTYPE_UDP) + session->hdr_len += 4; } } diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 5c53eb2a8ad9..d2395984645e 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -48,6 +48,11 @@ enum l2tp_l2spec_type { L2TP_L2SPECTYPE_DEFAULT, }; +enum l2tp_encap_type { + L2TP_ENCAPTYPE_UDP, + L2TP_ENCAPTYPE_IP, +}; + struct sk_buff; struct l2tp_stats { @@ -155,6 +160,7 @@ struct l2tp_session { struct l2tp_tunnel_cfg { int debug; /* bitmask of debug message * categories */ + enum l2tp_encap_type encap; }; struct l2tp_tunnel { @@ -170,6 +176,7 @@ struct l2tp_tunnel { char name[20]; /* for logging */ int debug; /* bitmask of debug message * categories */ + enum l2tp_encap_type encap; struct l2tp_stats stats; struct list_head list; /* Keep a list of all tunnels */ diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c new file mode 100644 index 000000000000..75bf784ba18d --- /dev/null +++ b/net/l2tp/l2tp_ip.c @@ -0,0 +1,679 @@ +/* + * L2TPv3 IP encapsulation support + * + * Copyright (c) 2008,2009,2010 Katalix Systems Ltd + * + * 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. + */ + +#include <linux/icmp.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/random.h> +#include <linux/socket.h> +#include <linux/l2tp.h> +#include <linux/in.h> +#include <net/sock.h> +#include <net/ip.h> +#include <net/icmp.h> +#include <net/udp.h> +#include <net/inet_common.h> +#include <net/inet_hashtables.h> +#include <net/tcp_states.h> +#include <net/protocol.h> +#include <net/xfrm.h> + +#include "l2tp_core.h" + +struct l2tp_ip_sock { + /* inet_sock has to be the first member of l2tp_ip_sock */ + struct inet_sock inet; + + __u32 conn_id; + __u32 peer_conn_id; + + __u64 tx_packets; + __u64 tx_bytes; + __u64 tx_errors; + __u64 rx_packets; + __u64 rx_bytes; + __u64 rx_errors; +}; + +static DEFINE_RWLOCK(l2tp_ip_lock); +static struct hlist_head l2tp_ip_table; +static struct hlist_head l2tp_ip_bind_table; + +static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) +{ + return (struct l2tp_ip_sock *)sk; +} + +static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) +{ + struct hlist_node *node; + struct sock *sk; + + sk_for_each_bound(sk, node, &l2tp_ip_bind_table) { + struct inet_sock *inet = inet_sk(sk); + struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk); + + if (l2tp == NULL) + continue; + + if ((l2tp->conn_id == tunnel_id) && +#ifdef CONFIG_NET_NS + (sk->sk_net == net) && +#endif + !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) && + !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) + goto found; + } + + sk = NULL; +found: + return sk; +} + +static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id) +{ + struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id); + if (sk) + sock_hold(sk); + + return sk; +} + +/* When processing receive frames, there are two cases to + * consider. Data frames consist of a non-zero session-id and an + * optional cookie. Control frames consist of a regular L2TP header + * preceded by 32-bits of zeros. + * + * L2TPv3 Session Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Session ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Cookie (optional, maximum 64 bits)... + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * L2TPv3 Control Message Header Over IP + * + * 0 1 2 3 + * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | (32 bits of zeros) | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * |T|L|x|x|S|x|x|x|x|x|x|x| Ver | Length | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Control Connection ID | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * | Ns | Nr | + * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + * + * All control frames are passed to userspace. + */ +static int l2tp_ip_recv(struct sk_buff *skb) +{ + struct sock *sk; + u32 session_id; + u32 tunnel_id; + unsigned char *ptr, *optr; + struct l2tp_session *session; + struct l2tp_tunnel *tunnel = NULL; + int length; + int offset; + + /* Point to L2TP header */ + optr = ptr = skb->data; + + if (!pskb_may_pull(skb, 4)) + goto discard; + + session_id = ntohl(*((__be32 *) ptr)); + ptr += 4; + + /* RFC3931: L2TP/IP packets have the first 4 bytes containing + * the session_id. If it is 0, the packet is a L2TP control + * frame and the session_id value can be discarded. + */ + if (session_id == 0) { + __skb_pull(skb, 4); + goto pass_up; + } + + /* Ok, this is a data packet. Lookup the session. */ + session = l2tp_session_find(&init_net, NULL, session_id); + if (session == NULL) + goto discard; + + tunnel = session->tunnel; + if (tunnel == NULL) + goto discard; + + /* Trace packet contents, if enabled */ + if (tunnel->debug & L2TP_MSG_DATA) { + length = min(32u, skb->len); + if (!pskb_may_pull(skb, length)) + goto discard; + + printk(KERN_DEBUG "%s: ip recv: ", tunnel->name); + + offset = 0; + do { + printk(" %02X", ptr[offset]); + } while (++offset < length); + + printk("\n"); + } + + l2tp_recv_common(session, skb, ptr, optr, 0, skb->len, tunnel->recv_payload_hook); + + return 0; + +pass_up: + /* Get the tunnel_id from the L2TP header */ + if (!pskb_may_pull(skb, 12)) + goto discard; + + if ((skb->data[0] & 0xc0) != 0xc0) + goto discard; + + tunnel_id = ntohl(*(__be32 *) &skb->data[4]); + tunnel = l2tp_tunnel_find(&init_net, tunnel_id); + if (tunnel != NULL) + sk = tunnel->sock; + else { + struct iphdr *iph = (struct iphdr *) skb_network_header(skb); + + read_lock_bh(&l2tp_ip_lock); + sk = __l2tp_ip_bind_lookup(&init_net, iph->daddr, 0, tunnel_id); + read_unlock_bh(&l2tp_ip_lock); + } + + if (sk == NULL) + goto discard; + + sock_hold(sk); + + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto discard_put; + + nf_reset(skb); + + return sk_receive_skb(sk, skb, 1); + +discard_put: + sock_put(sk); + +discard: + kfree_skb(skb); + return 0; +} + +static int l2tp_ip_open(struct sock *sk) +{ + /* Prevent autobind. We don't have ports. */ + inet_sk(sk)->inet_num = IPPROTO_L2TP; + + write_lock_bh(&l2tp_ip_lock); + sk_add_node(sk, &l2tp_ip_table); + write_unlock_bh(&l2tp_ip_lock); + + return 0; +} + +static void l2tp_ip_close(struct sock *sk, long timeout) +{ + write_lock_bh(&l2tp_ip_lock); + hlist_del_init(&sk->sk_bind_node); + hlist_del_init(&sk->sk_node); + write_unlock_bh(&l2tp_ip_lock); + sk_common_release(sk); +} + +static void l2tp_ip_destroy_sock(struct sock *sk) +{ + struct sk_buff *skb; + + while ((skb = __skb_dequeue_tail(&sk->sk_write_queue)) != NULL) + kfree_skb(skb); + + sk_refcnt_debug_dec(sk); +} + +static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_l2tpip *addr = (struct sockaddr_l2tpip *) uaddr; + int ret = -EINVAL; + int chk_addr_ret; + + ret = -EADDRINUSE; + read_lock_bh(&l2tp_ip_lock); + if (__l2tp_ip_bind_lookup(&init_net, addr->l2tp_addr.s_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id)) + goto out_in_use; + + read_unlock_bh(&l2tp_ip_lock); + + lock_sock(sk); + if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip)) + goto out; + + chk_addr_ret = inet_addr_type(&init_net, addr->l2tp_addr.s_addr); + ret = -EADDRNOTAVAIL; + if (addr->l2tp_addr.s_addr && chk_addr_ret != RTN_LOCAL && + chk_addr_ret != RTN_MULTICAST && chk_addr_ret != RTN_BROADCAST) + goto out; + + inet->inet_rcv_saddr = inet->inet_saddr = addr->l2tp_addr.s_addr; + if (chk_addr_ret == RTN_MULTICAST || chk_addr_ret == RTN_BROADCAST) + inet->inet_saddr = 0; /* Use device */ + sk_dst_reset(sk); + + l2tp_ip_sk(sk)->conn_id = addr->l2tp_conn_id; + + write_lock_bh(&l2tp_ip_lock); + sk_add_bind_node(sk, &l2tp_ip_bind_table); + sk_del_node_init(sk); + write_unlock_bh(&l2tp_ip_lock); + ret = 0; +out: + release_sock(sk); + + return ret; + +out_in_use: + read_unlock_bh(&l2tp_ip_lock); + + return ret; +} + +static int l2tp_ip_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + int rc; + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *) uaddr; + struct rtable *rt; + __be32 saddr; + int oif; + + rc = -EINVAL; + if (addr_len < sizeof(*lsa)) + goto out; + + rc = -EAFNOSUPPORT; + if (lsa->l2tp_family != AF_INET) + goto out; + + sk_dst_reset(sk); + + oif = sk->sk_bound_dev_if; + saddr = inet->inet_saddr; + + rc = -EINVAL; + if (ipv4_is_multicast(lsa->l2tp_addr.s_addr)) + goto out; + + rc = ip_route_connect(&rt, lsa->l2tp_addr.s_addr, saddr, + RT_CONN_FLAGS(sk), oif, + IPPROTO_L2TP, + 0, 0, sk, 1); + if (rc) { + if (rc == -ENETUNREACH) + IP_INC_STATS_BH(&init_net, IPSTATS_MIB_OUTNOROUTES); + goto out; + } + + rc = -ENETUNREACH; + if (rt->rt_flags & (RTCF_MULTICAST | RTCF_BROADCAST)) { + ip_rt_put(rt); + goto out; + } + + l2tp_ip_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; + + if (!inet->inet_saddr) + inet->inet_saddr = rt->rt_src; + if (!inet->inet_rcv_saddr) + inet->inet_rcv_saddr = rt->rt_src; + inet->inet_daddr = rt->rt_dst; + sk->sk_state = TCP_ESTABLISHED; + inet->inet_id = jiffies; + + sk_dst_set(sk, &rt->u.dst); + + write_lock_bh(&l2tp_ip_lock); + hlist_del_init(&sk->sk_bind_node); + sk_add_bind_node(sk, &l2tp_ip_bind_table); + write_unlock_bh(&l2tp_ip_lock); + + rc = 0; +out: + return rc; +} + +static int l2tp_ip_getname(struct socket *sock, struct sockaddr *uaddr, + int *uaddr_len, int peer) +{ + struct sock *sk = sock->sk; + struct inet_sock *inet = inet_sk(sk); + struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); + struct sockaddr_l2tpip *lsa = (struct sockaddr_l2tpip *)uaddr; + + memset(lsa, 0, sizeof(*lsa)); + lsa->l2tp_family = AF_INET; + if (peer) { + if (!inet->inet_dport) + return -ENOTCONN; + lsa->l2tp_conn_id = lsk->peer_conn_id; + lsa->l2tp_addr.s_addr = inet->inet_daddr; + } else { + __be32 addr = inet->inet_rcv_saddr; + if (!addr) + addr = inet->inet_saddr; + lsa->l2tp_conn_id = lsk->conn_id; + lsa->l2tp_addr.s_addr = addr; + } + *uaddr_len = sizeof(*lsa); + return 0; +} + +static int l2tp_ip_backlog_recv(struct sock *sk, struct sk_buff *skb) +{ + int rc; + + if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb)) + goto drop; + + nf_reset(skb); + + /* Charge it to the socket, dropping if the queue is full. */ + rc = sock_queue_rcv_skb(sk, skb); + if (rc < 0) + goto drop; + + return 0; + +drop: + IP_INC_STATS(&init_net, IPSTATS_MIB_INDISCARDS); + kfree_skb(skb); + return -1; +} + +/* Userspace will call sendmsg() on the tunnel socket to send L2TP + * control frames. + */ +static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len) +{ + struct sk_buff *skb; + int rc; + struct l2tp_ip_sock *lsa = l2tp_ip_sk(sk); + struct inet_sock *inet = inet_sk(sk); + struct ip_options *opt = inet->opt; + struct rtable *rt = NULL; + int connected = 0; + __be32 daddr; + + if (sock_flag(sk, SOCK_DEAD)) + return -ENOTCONN; + + /* Get and verify the address. */ + if (msg->msg_name) { + struct sockaddr_l2tpip *lip = (struct sockaddr_l2tpip *) msg->msg_name; + if (msg->msg_namelen < sizeof(*lip)) + return -EINVAL; + + if (lip->l2tp_family != AF_INET) { + if (lip->l2tp_family != AF_UNSPEC) + return -EAFNOSUPPORT; + } + + daddr = lip->l2tp_addr.s_addr; + } else { + if (sk->sk_state != TCP_ESTABLISHED) + return -EDESTADDRREQ; + + daddr = inet->inet_daddr; + connected = 1; + } + + /* Allocate a socket buffer */ + rc = -ENOMEM; + skb = sock_wmalloc(sk, 2 + NET_SKB_PAD + sizeof(struct iphdr) + + 4 + len, 0, GFP_KERNEL); + if (!skb) + goto error; + + /* Reserve space for headers, putting IP header on 4-byte boundary. */ + skb_reserve(skb, 2 + NET_SKB_PAD); + skb_reset_network_header(skb); + skb_reserve(skb, sizeof(struct iphdr)); + skb_reset_transport_header(skb); + + /* Insert 0 session_id */ + *((__be32 *) skb_put(skb, 4)) = 0; + + /* Copy user data into skb */ + rc = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len); + if (rc < 0) { + kfree_skb(skb); + goto error; + } + + if (connected) + rt = (struct rtable *) __sk_dst_check(sk, 0); + + if (rt == NULL) { + /* Use correct destination address if we have options. */ + if (opt && opt->srr) + daddr = opt->faddr; + + { + struct flowi fl = { .oif = sk->sk_bound_dev_if, + .nl_u = { .ip4_u = { + .daddr = daddr, + .saddr = inet->inet_saddr, + .tos = RT_CONN_FLAGS(sk) } }, + .proto = sk->sk_protocol, + .flags = inet_sk_flowi_flags(sk), + .uli_u = { .ports = { + .sport = inet->inet_sport, + .dport = inet->inet_dport } } }; + + /* If this fails, retransmit mechanism of transport layer will + * keep trying until route appears or the connection times + * itself out. + */ + security_sk_classify_flow(sk, &fl); + if (ip_route_output_flow(sock_net(sk), &rt, &fl, sk, 0)) + goto no_route; + } + sk_setup_caps(sk, &rt->u.dst); + } + skb_dst_set(skb, dst_clone(&rt->u.dst)); + + /* Queue the packet to IP for output */ + rc = ip_queue_xmit(skb, 0); + +error: + /* Update stats */ + if (rc >= 0) { + lsa->tx_packets++; + lsa->tx_bytes += len; + rc = len; + } else { + lsa->tx_errors++; + } + + return rc; + +no_route: + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); + kfree_skb(skb); + return -EHOSTUNREACH; +} + +static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, + size_t len, int noblock, int flags, int *addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct l2tp_ip_sock *lsk = l2tp_ip_sk(sk); + size_t copied = 0; + int err = -EOPNOTSUPP; + struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name; + struct sk_buff *skb; + + if (flags & MSG_OOB) + goto out; + + if (addr_len) + *addr_len = sizeof(*sin); + + skb = skb_recv_datagram(sk, flags, noblock, &err); + if (!skb) + goto out; + + copied = skb->len; + if (len < copied) { + msg->msg_flags |= MSG_TRUNC; + copied = len; + } + + err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); + if (err) + goto done; + + sock_recv_timestamp(msg, sk, skb); + + /* Copy the address. */ + if (sin) { + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = ip_hdr(skb)->saddr; + sin->sin_port = 0; + memset(&sin->sin_zero, 0, sizeof(sin->sin_zero)); + } + if (inet->cmsg_flags) + ip_cmsg_recv(msg, skb); + if (flags & MSG_TRUNC) + copied = skb->len; +done: + skb_free_datagram(sk, skb); +out: + if (err) { + lsk->rx_errors++; + return err; + } + + lsk->rx_packets++; + lsk->rx_bytes += copied; + + return copied; +} + +struct proto l2tp_ip_prot = { + .name = "L2TP/IP", + .owner = THIS_MODULE, + .init = l2tp_ip_open, + .close = l2tp_ip_close, + .bind = l2tp_ip_bind, + .connect = l2tp_ip_connect, + .disconnect = udp_disconnect, + .ioctl = udp_ioctl, + .destroy = l2tp_ip_destroy_sock, + .setsockopt = ip_setsockopt, + .getsockopt = ip_getsockopt, + .sendmsg = l2tp_ip_sendmsg, + .recvmsg = l2tp_ip_recvmsg, + .backlog_rcv = l2tp_ip_backlog_recv, + .hash = inet_hash, + .unhash = inet_unhash, + .obj_size = sizeof(struct l2tp_ip_sock), +#ifdef CONFIG_COMPAT + .compat_setsockopt = compat_ip_setsockopt, + .compat_getsockopt = compat_ip_getsockopt, +#endif +}; + +static const struct proto_ops l2tp_ip_ops = { + .family = PF_INET, + .owner = THIS_MODULE, + .release = inet_release, + .bind = inet_bind, + .connect = inet_dgram_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = l2tp_ip_getname, + .poll = datagram_poll, + .ioctl = inet_ioctl, + .listen = sock_no_listen, + .shutdown = inet_shutdown, + .setsockopt = sock_common_setsockopt, + .getsockopt = sock_common_getsockopt, + .sendmsg = inet_sendmsg, + .recvmsg = sock_common_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, +#ifdef CONFIG_COMPAT + .compat_setsockopt = compat_sock_common_setsockopt, + .compat_getsockopt = compat_sock_common_getsockopt, +#endif +}; + +static struct inet_protosw l2tp_ip_protosw = { + .type = SOCK_DGRAM, + .protocol = IPPROTO_L2TP, + .prot = &l2tp_ip_prot, + .ops = &l2tp_ip_ops, + .no_check = 0, +}; + +static struct net_protocol l2tp_ip_protocol __read_mostly = { + .handler = l2tp_ip_recv, +}; + +static int __init l2tp_ip_init(void) +{ + int err; + + printk(KERN_INFO "L2TP IP encapsulation support (L2TPv3)\n"); + + err = proto_register(&l2tp_ip_prot, 1); + if (err != 0) + goto out; + + err = inet_add_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); + if (err) + goto out1; + + inet_register_protosw(&l2tp_ip_protosw); + return 0; + +out1: + proto_unregister(&l2tp_ip_prot); +out: + return err; +} + +static void __exit l2tp_ip_exit(void) +{ + inet_unregister_protosw(&l2tp_ip_protosw); + inet_del_protocol(&l2tp_ip_protocol, IPPROTO_L2TP); + proto_unregister(&l2tp_ip_prot); +} + +module_init(l2tp_ip_init); +module_exit(l2tp_ip_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); +MODULE_DESCRIPTION("L2TP over IP"); +MODULE_VERSION("1.0"); +MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_INET, SOCK_DGRAM, IPPROTO_L2TP); diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index e5b531266541..63fc62baeeb9 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -305,6 +305,7 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh struct l2tp_session *session; struct l2tp_tunnel *tunnel; struct pppol2tp_session *ps; + int uhlen; error = -ENOTCONN; if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) @@ -321,10 +322,12 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh if (tunnel == NULL) goto error_put_sess; + uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; + /* Allocate a socket buffer */ error = -ENOMEM; skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + - sizeof(struct udphdr) + session->hdr_len + + uhlen + session->hdr_len + sizeof(ppph) + total_len, 0, GFP_KERNEL); if (!skb) @@ -335,7 +338,7 @@ static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msgh skb_reset_network_header(skb); skb_reserve(skb, sizeof(struct iphdr)); skb_reset_transport_header(skb); - skb_reserve(skb, sizeof(struct udphdr)); + skb_reserve(skb, uhlen); /* Add PPP header */ skb->data[0] = ppph[0]; |