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Release 4.8 net/l2tp/l2tp_ip6.c

Directory: net/l2tp
/*
 * L2TPv3 IP encapsulation support for IPv6
 *
 * Copyright (c) 2012 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.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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 <linux/in6.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/inet6_hashtables.h>
#include <net/tcp_states.h>
#include <net/protocol.h>
#include <net/xfrm.h>

#include <net/transp_v6.h>
#include <net/addrconf.h>
#include <net/ip6_route.h>

#include "l2tp_core.h"


struct l2tp_ip6_sock {
	/* inet_sock has to be the first member of l2tp_ip6_sock */
	
struct inet_sock	inet;

	
u32			conn_id;
	
u32			peer_conn_id;

	/* ipv6_pinfo has to be the last member of l2tp_ip6_sock, see
           inet6_sk_generic */
	
struct ipv6_pinfo	inet6;
};

static DEFINE_RWLOCK(l2tp_ip6_lock);

static struct hlist_head l2tp_ip6_table;

static struct hlist_head l2tp_ip6_bind_table;


static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) { return (struct l2tp_ip6_sock *)sk; }

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static struct sock *__l2tp_ip6_bind_lookup(struct net *net, struct in6_addr *laddr, int dif, u32 tunnel_id) { struct sock *sk; sk_for_each_bound(sk, &l2tp_ip6_bind_table) { const struct in6_addr *addr = inet6_rcv_saddr(sk); struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk); if (l2tp == NULL) continue; if ((l2tp->conn_id == tunnel_id) && net_eq(sock_net(sk), net) && !(addr && ipv6_addr_equal(addr, laddr)) && !(sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif)) goto found; } sk = NULL; found: return sk; }

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static inline struct sock *l2tp_ip6_bind_lookup(struct net *net, struct in6_addr *laddr, int dif, u32 tunnel_id) { struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id); if (sk) sock_hold(sk); return sk; }

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/* 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_ip6_recv(struct sk_buff *skb) { struct net *net = dev_net(skb->dev); struct sock *sk; u32 session_id; u32 tunnel_id; unsigned char *ptr, *optr; struct l2tp_session *session; struct l2tp_tunnel *tunnel = NULL; int length; if (!pskb_may_pull(skb, 4)) goto discard; /* Point to L2TP header */ optr = ptr = skb->data; 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(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; /* Point to L2TP header */ optr = ptr = skb->data; ptr += 4; pr_debug("%s: ip recv\n", tunnel->name); print_hex_dump_bytes("", DUMP_PREFIX_OFFSET, ptr, length); } 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(net, tunnel_id); if (tunnel != NULL) sk = tunnel->sock; else { struct ipv6hdr *iph = ipv6_hdr(skb); read_lock_bh(&l2tp_ip6_lock); sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, 0, tunnel_id); read_unlock_bh(&l2tp_ip6_lock); } if (sk == NULL) goto discard; sock_hold(sk); if (!xfrm6_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; }

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joe perchesjoe perches71.67%125.00%
Total419100.00%4100.00%


static int l2tp_ip6_open(struct sock *sk) { /* Prevent autobind. We don't have ports. */ inet_sk(sk)->inet_num = IPPROTO_L2TP; write_lock_bh(&l2tp_ip6_lock); sk_add_node(sk, &l2tp_ip6_table); write_unlock_bh(&l2tp_ip6_lock); return 0; }

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static void l2tp_ip6_close(struct sock *sk, long timeout) { write_lock_bh(&l2tp_ip6_lock); hlist_del_init(&sk->sk_bind_node); sk_del_node_init(sk); write_unlock_bh(&l2tp_ip6_lock); sk_common_release(sk); }

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static void l2tp_ip6_destroy_sock(struct sock *sk) { struct l2tp_tunnel *tunnel = l2tp_sock_to_tunnel(sk); lock_sock(sk); ip6_flush_pending_frames(sk); release_sock(sk); if (tunnel) { l2tp_tunnel_closeall(tunnel); sock_put(sk); } inet6_destroy_sock(sk); }

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static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct inet_sock *inet = inet_sk(sk); struct ipv6_pinfo *np = inet6_sk(sk); struct sockaddr_l2tpip6 *addr = (struct sockaddr_l2tpip6 *) uaddr; struct net *net = sock_net(sk); __be32 v4addr = 0; int addr_type; int err; if (!sock_flag(sk, SOCK_ZAPPED)) return -EINVAL; if (addr->l2tp_family != AF_INET6) return -EINVAL; if (addr_len < sizeof(*addr)) return -EINVAL; addr_type = ipv6_addr_type(&addr->l2tp_addr); /* l2tp_ip6 sockets are IPv6 only */ if (addr_type == IPV6_ADDR_MAPPED) return -EADDRNOTAVAIL; /* L2TP is point-point, not multicast */ if (addr_type & IPV6_ADDR_MULTICAST) return -EADDRNOTAVAIL; err = -EADDRINUSE; read_lock_bh(&l2tp_ip6_lock); if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, sk->sk_bound_dev_if, addr->l2tp_conn_id)) goto out_in_use; read_unlock_bh(&l2tp_ip6_lock); lock_sock(sk); err = -EINVAL; if (sk->sk_state != TCP_CLOSE) goto out_unlock; /* Check if the address belongs to the host. */ rcu_read_lock(); if (addr_type != IPV6_ADDR_ANY) { struct net_device *dev = NULL; if (addr_type & IPV6_ADDR_LINKLOCAL) { if (addr_len >= sizeof(struct sockaddr_in6) && addr->l2tp_scope_id) { /* Override any existing binding, if another * one is supplied by user. */ sk->sk_bound_dev_if = addr->l2tp_scope_id; } /* Binding to link-local address requires an interface */ if (!sk->sk_bound_dev_if) goto out_unlock_rcu; err = -ENODEV; dev = dev_get_by_index_rcu(sock_net(sk), sk->sk_bound_dev_if); if (!dev) goto out_unlock_rcu; } /* ipv4 addr of the socket is invalid. Only the * unspecified and mapped address have a v4 equivalent. */ v4addr = LOOPBACK4_IPV6; err = -EADDRNOTAVAIL; if (!ipv6_chk_addr(sock_net(sk), &addr->l2tp_addr, dev, 0)) goto out_unlock_rcu; } rcu_read_unlock(); inet->inet_rcv_saddr = inet->inet_saddr = v4addr; sk->sk_v6_rcv_saddr = addr->l2tp_addr; np->saddr = addr->l2tp_addr; l2tp_ip6_sk(sk)->conn_id = addr->l2tp_conn_id; write_lock_bh(&l2tp_ip6_lock); sk_add_bind_node(sk, &l2tp_ip6_bind_table); sk_del_node_init(sk); write_unlock_bh(&l2tp_ip6_lock); sock_reset_flag(sk, SOCK_ZAPPED); release_sock(sk); return 0; out_unlock_rcu: rcu_read_unlock(); out_unlock: release_sock(sk); return err; out_in_use: read_unlock_bh(&l2tp_ip6_lock); return err; }

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eric dumazeteric dumazet20.46%125.00%
Total434100.00%4100.00%


static int l2tp_ip6_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) { struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *) uaddr; struct sockaddr_in6 *usin = (struct sockaddr_in6 *) uaddr; struct in6_addr *daddr; int addr_type; int rc; if (sock_flag(sk, SOCK_ZAPPED)) /* Must bind first - autobinding does not work */ return -EINVAL; if (addr_len < sizeof(*lsa)) return -EINVAL; if (usin->sin6_family != AF_INET6) return -EINVAL; addr_type = ipv6_addr_type(&usin->sin6_addr); if (addr_type & IPV6_ADDR_MULTICAST) return -EINVAL; if (addr_type & IPV6_ADDR_MAPPED) { daddr = &usin->sin6_addr; if (ipv4_is_multicast(daddr->s6_addr32[3])) return -EINVAL; } rc = ip6_datagram_connect(sk, uaddr, addr_len); lock_sock(sk); l2tp_ip6_sk(sk)->peer_conn_id = lsa->l2tp_conn_id; write_lock_bh(&l2tp_ip6_lock); hlist_del_init(&sk->sk_bind_node); sk_add_bind_node(sk, &l2tp_ip6_bind_table); write_unlock_bh(&l2tp_ip6_lock); release_sock(sk); return rc; }

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Total208100.00%3100.00%


static int l2tp_ip6_disconnect(struct sock *sk, int flags) { if (sock_flag(sk, SOCK_ZAPPED)) return 0; return udp_disconnect(sk, flags); }

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static int l2tp_ip6_getname(struct socket *sock, struct sockaddr *uaddr, int *uaddr_len, int peer) { struct sockaddr_l2tpip6 *lsa = (struct sockaddr_l2tpip6 *)uaddr; struct sock *sk = sock->sk; struct ipv6_pinfo *np = inet6_sk(sk); struct l2tp_ip6_sock *lsk = l2tp_ip6_sk(sk); lsa->l2tp_family = AF_INET6; lsa->l2tp_flowinfo = 0; lsa->l2tp_scope_id = 0; lsa->l2tp_unused = 0; if (peer) { if (!lsk->peer_conn_id) return -ENOTCONN; lsa->l2tp_conn_id = lsk->peer_conn_id; lsa->l2tp_addr = sk->sk_v6_daddr; if (np->sndflow) lsa->l2tp_flowinfo = np->flow_label; } else { if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) lsa->l2tp_addr = np->saddr; else lsa->l2tp_addr = sk->sk_v6_rcv_saddr; lsa->l2tp_conn_id = lsk->conn_id; } if (ipv6_addr_type(&lsa->l2tp_addr) & IPV6_ADDR_LINKLOCAL) lsa->l2tp_scope_id = sk->sk_bound_dev_if; *uaddr_len = sizeof(*lsa); return 0; }

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Total205100.00%3100.00%


static int l2tp_ip6_backlog_recv(struct sock *sk, struct sk_buff *skb) { int rc; /* 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(sock_net(sk), IPSTATS_MIB_INDISCARDS); kfree_skb(skb); return -1; }

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static int l2tp_ip6_push_pending_frames(struct sock *sk) { struct sk_buff *skb; __be32 *transhdr = NULL; int err = 0; skb = skb_peek(&sk->sk_write_queue); if (skb == NULL) goto out; transhdr = (__be32 *)skb_transport_header(skb); *transhdr = 0; err = ip6_push_pending_frames(sk); out: return err; }

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/* Userspace will call sendmsg() on the tunnel socket to send L2TP * control frames. */
static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) { struct ipv6_txoptions opt_space; DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa, msg->msg_name); struct in6_addr *daddr, *final_p, final; struct ipv6_pinfo *np = inet6_sk(sk); struct ipv6_txoptions *opt_to_free = NULL; struct ipv6_txoptions *opt = NULL; struct ip6_flowlabel *flowlabel = NULL; struct dst_entry *dst = NULL; struct flowi6 fl6; struct sockcm_cookie sockc_unused = {0}; struct ipcm6_cookie ipc6; int addr_len = msg->msg_namelen; int transhdrlen = 4; /* zero session-id */ int ulen = len + transhdrlen; int err; /* Rough check on arithmetic overflow, better check is made in ip6_append_data(). */ if (len > INT_MAX) return -EMSGSIZE; /* Mirror BSD error message compatibility */ if (msg->msg_flags & MSG_OOB) return -EOPNOTSUPP; /* * Get and verify the address. */ memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_mark = sk->sk_mark; ipc6.hlimit = -1; ipc6.tclass = -1; ipc6.dontfrag = -1; if (lsa) { if (addr_len < SIN6_LEN_RFC2133) return -EINVAL; if (lsa->l2tp_family && lsa->l2tp_family != AF_INET6) return -EAFNOSUPPORT; daddr = &lsa->l2tp_addr; if (np->sndflow) { fl6.flowlabel = lsa->l2tp_flowinfo & IPV6_FLOWINFO_MASK; if (fl6.flowlabel&IPV6_FLOWLABEL_MASK) { flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); if (flowlabel == NULL) return -EINVAL; } } /* * Otherwise it will be difficult to maintain * sk->sk_dst_cache. */ if (sk->sk_state == TCP_ESTABLISHED && ipv6_addr_equal(daddr, &sk->sk_v6_daddr)) daddr = &sk->sk_v6_daddr; if (addr_len >= sizeof(struct sockaddr_in6) && lsa->l2tp_scope_id && ipv6_addr_type(daddr) & IPV6_ADDR_LINKLOCAL) fl6.flowi6_oif = lsa->l2tp_scope_id; } else { if (sk->sk_state != TCP_ESTABLISHED) return -EDESTADDRREQ; daddr = &sk->sk_v6_daddr; fl6.flowlabel = np->flow_label; } if (fl6.flowi6_oif == 0) fl6.flowi6_oif = sk->sk_bound_dev_if; if (msg->msg_controllen) { opt = &opt_space; memset(opt, 0, sizeof(struct ipv6_txoptions)); opt->tot_len = sizeof(struct ipv6_txoptions); ipc6.opt = opt; err = ip6_datagram_send_ctl(sock_net(sk), sk, msg, &fl6, &ipc6, &sockc_unused); if (err < 0) { fl6_sock_release(flowlabel); return err; } if ((fl6.flowlabel & IPV6_FLOWLABEL_MASK) && !flowlabel) { flowlabel = fl6_sock_lookup(sk, fl6.flowlabel); if (flowlabel == NULL) return -EINVAL; } if (!(opt->opt_nflen|opt->opt_flen)) opt = NULL; } if (!opt) { opt = txopt_get(np); opt_to_free = opt; } if (flowlabel) opt = fl6_merge_options(&opt_space, flowlabel, opt); opt = ipv6_fixup_options(&opt_space, opt); ipc6.opt = opt; fl6.flowi6_proto = sk->sk_protocol; if (!ipv6_addr_any(daddr)) fl6.daddr = *daddr; else fl6.daddr.s6_addr[15] = 0x1; /* :: means loopback (BSD'ism) */ if (ipv6_addr_any(&fl6.saddr) && !ipv6_addr_any(&np->saddr)) fl6.saddr = np->saddr; final_p = fl6_update_dst(&fl6, opt, &final); if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) fl6.flowi6_oif = np->mcast_oif; else if (!fl6.flowi6_oif) fl6.flowi6_oif = np->ucast_oif; security_sk_classify_flow(sk, flowi6_to_flowi(&fl6)); if (ipc6.tclass < 0) ipc6.tclass = np->tclass; fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); dst = ip6_dst_lookup_flow(sk, &fl6, final_p); if (IS_ERR(dst)) { err = PTR_ERR(dst); goto out; } if (ipc6.hlimit < 0) ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); if (ipc6.dontfrag < 0) ipc6.dontfrag = np->dontfrag; if (msg->msg_flags & MSG_CONFIRM) goto do_confirm; back_from_confirm: lock_sock(sk); err = ip6_append_data(sk, ip_generic_getfrag, msg, ulen, transhdrlen, &ipc6, &fl6, (struct rt6_info *)dst, msg->msg_flags, &sockc_unused); if (err) ip6_flush_pending_frames(sk); else if (!(msg->msg_flags & MSG_MORE)) err = l2tp_ip6_push_pending_frames(sk); release_sock(sk); done: dst_release(dst); out: fl6_sock_release(flowlabel); txopt_put(opt_to_free); return err < 0 ? err : len; do_confirm: dst_confirm(dst); if (!(msg->msg_flags & MSG_PROBE) || len) goto back_from_confirm; err = 0; goto done; }

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chris elstonchris elston80085.74%110.00%
wei wangwei wang485.14%110.00%
hannes frederic sowahannes frederic sowa313.32%110.00%
eric dumazeteric dumazet272.89%220.00%
soheil hassas yeganehsoheil hassas yeganeh131.39%220.00%
steffen hurrlesteffen hurrle70.75%110.00%
lorenzo colittilorenzo colitti60.64%110.00%
tom parkintom parkin10.11%110.00%
Total933100.00%10100.00%


static int l2tp_ip6_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int noblock, int flags, int *addr_len) { struct ipv6_pinfo *np = inet6_sk(sk); DECLARE_SOCKADDR(struct sockaddr_l2tpip6 *, lsa,