| /* |
| * Point-to-Point Tunneling Protocol for Linux |
| * |
| * Authors: Dmitry Kozlov <xeb@mail.ru> |
| * |
| * 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/string.h> |
| #include <linux/module.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/errno.h> |
| #include <linux/netdevice.h> |
| #include <linux/net.h> |
| #include <linux/skbuff.h> |
| #include <linux/vmalloc.h> |
| #include <linux/init.h> |
| #include <linux/ppp_channel.h> |
| #include <linux/ppp_defs.h> |
| #include <linux/if_pppox.h> |
| #include <linux/if_ppp.h> |
| #include <linux/notifier.h> |
| #include <linux/file.h> |
| #include <linux/in.h> |
| #include <linux/ip.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv4.h> |
| #include <linux/version.h> |
| #include <linux/rcupdate.h> |
| #include <linux/spinlock.h> |
| |
| #include <net/sock.h> |
| #include <net/protocol.h> |
| #include <net/ip.h> |
| #include <net/icmp.h> |
| #include <net/route.h> |
| #include <net/gre.h> |
| |
| #include <linux/uaccess.h> |
| |
| #define PPTP_DRIVER_VERSION "0.8.5" |
| |
| #define MAX_CALLID 65535 |
| |
| static DECLARE_BITMAP(callid_bitmap, MAX_CALLID + 1); |
| static struct pppox_sock **callid_sock; |
| |
| static DEFINE_SPINLOCK(chan_lock); |
| |
| static struct proto pptp_sk_proto __read_mostly; |
| static const struct ppp_channel_ops pptp_chan_ops; |
| static const struct proto_ops pptp_ops; |
| |
| #define PPP_LCP_ECHOREQ 0x09 |
| #define PPP_LCP_ECHOREP 0x0A |
| #define SC_RCV_BITS (SC_RCV_B7_1|SC_RCV_B7_0|SC_RCV_ODDP|SC_RCV_EVNP) |
| |
| #define MISSING_WINDOW 20 |
| #define WRAPPED(curseq, lastseq)\ |
| ((((curseq) & 0xffffff00) == 0) &&\ |
| (((lastseq) & 0xffffff00) == 0xffffff00)) |
| |
| #define PPTP_GRE_PROTO 0x880B |
| #define PPTP_GRE_VER 0x1 |
| |
| #define PPTP_GRE_FLAG_C 0x80 |
| #define PPTP_GRE_FLAG_R 0x40 |
| #define PPTP_GRE_FLAG_K 0x20 |
| #define PPTP_GRE_FLAG_S 0x10 |
| #define PPTP_GRE_FLAG_A 0x80 |
| |
| #define PPTP_GRE_IS_C(f) ((f)&PPTP_GRE_FLAG_C) |
| #define PPTP_GRE_IS_R(f) ((f)&PPTP_GRE_FLAG_R) |
| #define PPTP_GRE_IS_K(f) ((f)&PPTP_GRE_FLAG_K) |
| #define PPTP_GRE_IS_S(f) ((f)&PPTP_GRE_FLAG_S) |
| #define PPTP_GRE_IS_A(f) ((f)&PPTP_GRE_FLAG_A) |
| |
| #define PPTP_HEADER_OVERHEAD (2+sizeof(struct pptp_gre_header)) |
| struct pptp_gre_header { |
| u8 flags; |
| u8 ver; |
| u16 protocol; |
| u16 payload_len; |
| u16 call_id; |
| u32 seq; |
| u32 ack; |
| } __packed; |
| |
| static struct pppox_sock *lookup_chan(u16 call_id, __be32 s_addr) |
| { |
| struct pppox_sock *sock; |
| struct pptp_opt *opt; |
| |
| rcu_read_lock(); |
| sock = rcu_dereference(callid_sock[call_id]); |
| if (sock) { |
| opt = &sock->proto.pptp; |
| if (opt->dst_addr.sin_addr.s_addr != s_addr) |
| sock = NULL; |
| else |
| sock_hold(sk_pppox(sock)); |
| } |
| rcu_read_unlock(); |
| |
| return sock; |
| } |
| |
| static int lookup_chan_dst(u16 call_id, __be32 d_addr) |
| { |
| struct pppox_sock *sock; |
| struct pptp_opt *opt; |
| int i; |
| |
| rcu_read_lock(); |
| for (i = find_next_bit(callid_bitmap, MAX_CALLID, 1); i < MAX_CALLID; |
| i = find_next_bit(callid_bitmap, MAX_CALLID, i + 1)) { |
| sock = rcu_dereference(callid_sock[i]); |
| if (!sock) |
| continue; |
| opt = &sock->proto.pptp; |
| if (opt->dst_addr.call_id == call_id && |
| opt->dst_addr.sin_addr.s_addr == d_addr) |
| break; |
| } |
| rcu_read_unlock(); |
| |
| return i < MAX_CALLID; |
| } |
| |
| static int add_chan(struct pppox_sock *sock) |
| { |
| static int call_id; |
| |
| spin_lock(&chan_lock); |
| if (!sock->proto.pptp.src_addr.call_id) { |
| call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, call_id + 1); |
| if (call_id == MAX_CALLID) { |
| call_id = find_next_zero_bit(callid_bitmap, MAX_CALLID, 1); |
| if (call_id == MAX_CALLID) |
| goto out_err; |
| } |
| sock->proto.pptp.src_addr.call_id = call_id; |
| } else if (test_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap)) |
| goto out_err; |
| |
| set_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap); |
| rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], sock); |
| spin_unlock(&chan_lock); |
| |
| return 0; |
| |
| out_err: |
| spin_unlock(&chan_lock); |
| return -1; |
| } |
| |
| static void del_chan(struct pppox_sock *sock) |
| { |
| spin_lock(&chan_lock); |
| clear_bit(sock->proto.pptp.src_addr.call_id, callid_bitmap); |
| rcu_assign_pointer(callid_sock[sock->proto.pptp.src_addr.call_id], NULL); |
| spin_unlock(&chan_lock); |
| synchronize_rcu(); |
| } |
| |
| static int pptp_xmit(struct ppp_channel *chan, struct sk_buff *skb) |
| { |
| struct sock *sk = (struct sock *) chan->private; |
| struct pppox_sock *po = pppox_sk(sk); |
| struct pptp_opt *opt = &po->proto.pptp; |
| struct pptp_gre_header *hdr; |
| unsigned int header_len = sizeof(*hdr); |
| struct flowi4 fl4; |
| int islcp; |
| int len; |
| unsigned char *data; |
| __u32 seq_recv; |
| |
| |
| struct rtable *rt; |
| struct net_device *tdev; |
| struct iphdr *iph; |
| int max_headroom; |
| |
| if (sk_pppox(po)->sk_state & PPPOX_DEAD) |
| goto tx_error; |
| |
| rt = ip_route_output_ports(&init_net, &fl4, NULL, |
| opt->dst_addr.sin_addr.s_addr, |
| opt->src_addr.sin_addr.s_addr, |
| 0, 0, IPPROTO_GRE, |
| RT_TOS(0), 0); |
| if (IS_ERR(rt)) |
| goto tx_error; |
| |
| tdev = rt->dst.dev; |
| |
| max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(*iph) + sizeof(*hdr) + 2; |
| |
| if (skb_headroom(skb) < max_headroom || skb_cloned(skb) || skb_shared(skb)) { |
| struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom); |
| if (!new_skb) { |
| ip_rt_put(rt); |
| goto tx_error; |
| } |
| if (skb->sk) |
| skb_set_owner_w(new_skb, skb->sk); |
| kfree_skb(skb); |
| skb = new_skb; |
| } |
| |
| data = skb->data; |
| islcp = ((data[0] << 8) + data[1]) == PPP_LCP && 1 <= data[2] && data[2] <= 7; |
| |
| /* compress protocol field */ |
| if ((opt->ppp_flags & SC_COMP_PROT) && data[0] == 0 && !islcp) |
| skb_pull(skb, 1); |
| |
| /* Put in the address/control bytes if necessary */ |
| if ((opt->ppp_flags & SC_COMP_AC) == 0 || islcp) { |
| data = skb_push(skb, 2); |
| data[0] = PPP_ALLSTATIONS; |
| data[1] = PPP_UI; |
| } |
| |
| len = skb->len; |
| |
| seq_recv = opt->seq_recv; |
| |
| if (opt->ack_sent == seq_recv) |
| header_len -= sizeof(hdr->ack); |
| |
| /* Push down and install GRE header */ |
| skb_push(skb, header_len); |
| hdr = (struct pptp_gre_header *)(skb->data); |
| |
| hdr->flags = PPTP_GRE_FLAG_K; |
| hdr->ver = PPTP_GRE_VER; |
| hdr->protocol = htons(PPTP_GRE_PROTO); |
| hdr->call_id = htons(opt->dst_addr.call_id); |
| |
| hdr->flags |= PPTP_GRE_FLAG_S; |
| hdr->seq = htonl(++opt->seq_sent); |
| if (opt->ack_sent != seq_recv) { |
| /* send ack with this message */ |
| hdr->ver |= PPTP_GRE_FLAG_A; |
| hdr->ack = htonl(seq_recv); |
| opt->ack_sent = seq_recv; |
| } |
| hdr->payload_len = htons(len); |
| |
| /* Push down and install the IP header. */ |
| |
| skb_reset_transport_header(skb); |
| skb_push(skb, sizeof(*iph)); |
| skb_reset_network_header(skb); |
| memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED | IPSKB_REROUTED); |
| |
| iph = ip_hdr(skb); |
| iph->version = 4; |
| iph->ihl = sizeof(struct iphdr) >> 2; |
| if (ip_dont_fragment(sk, &rt->dst)) |
| iph->frag_off = htons(IP_DF); |
| else |
| iph->frag_off = 0; |
| iph->protocol = IPPROTO_GRE; |
| iph->tos = 0; |
| iph->daddr = fl4.daddr; |
| iph->saddr = fl4.saddr; |
| iph->ttl = ip4_dst_hoplimit(&rt->dst); |
| iph->tot_len = htons(skb->len); |
| |
| skb_dst_drop(skb); |
| skb_dst_set(skb, &rt->dst); |
| |
| nf_reset(skb); |
| |
| skb->ip_summed = CHECKSUM_NONE; |
| ip_select_ident(iph, &rt->dst, NULL); |
| ip_send_check(iph); |
| |
| ip_local_out(skb); |
| |
| tx_error: |
| return 1; |
| } |
| |
| static int pptp_rcv_core(struct sock *sk, struct sk_buff *skb) |
| { |
| struct pppox_sock *po = pppox_sk(sk); |
| struct pptp_opt *opt = &po->proto.pptp; |
| int headersize, payload_len, seq; |
| __u8 *payload; |
| struct pptp_gre_header *header; |
| |
| if (!(sk->sk_state & PPPOX_CONNECTED)) { |
| if (sock_queue_rcv_skb(sk, skb)) |
| goto drop; |
| return NET_RX_SUCCESS; |
| } |
| |
| header = (struct pptp_gre_header *)(skb->data); |
| |
| /* test if acknowledgement present */ |
| if (PPTP_GRE_IS_A(header->ver)) { |
| __u32 ack = (PPTP_GRE_IS_S(header->flags)) ? |
| header->ack : header->seq; /* ack in different place if S = 0 */ |
| |
| ack = ntohl(ack); |
| |
| if (ack > opt->ack_recv) |
| opt->ack_recv = ack; |
| /* also handle sequence number wrap-around */ |
| if (WRAPPED(ack, opt->ack_recv)) |
| opt->ack_recv = ack; |
| } |
| |
| /* test if payload present */ |
| if (!PPTP_GRE_IS_S(header->flags)) |
| goto drop; |
| |
| headersize = sizeof(*header); |
| payload_len = ntohs(header->payload_len); |
| seq = ntohl(header->seq); |
| |
| /* no ack present? */ |
| if (!PPTP_GRE_IS_A(header->ver)) |
| headersize -= sizeof(header->ack); |
| /* check for incomplete packet (length smaller than expected) */ |
| if (skb->len - headersize < payload_len) |
| goto drop; |
| |
| payload = skb->data + headersize; |
| /* check for expected sequence number */ |
| if (seq < opt->seq_recv + 1 || WRAPPED(opt->seq_recv, seq)) { |
| if ((payload[0] == PPP_ALLSTATIONS) && (payload[1] == PPP_UI) && |
| (PPP_PROTOCOL(payload) == PPP_LCP) && |
| ((payload[4] == PPP_LCP_ECHOREQ) || (payload[4] == PPP_LCP_ECHOREP))) |
| goto allow_packet; |
| } else { |
| opt->seq_recv = seq; |
| allow_packet: |
| skb_pull(skb, headersize); |
| |
| if (payload[0] == PPP_ALLSTATIONS && payload[1] == PPP_UI) { |
| /* chop off address/control */ |
| if (skb->len < 3) |
| goto drop; |
| skb_pull(skb, 2); |
| } |
| |
| if ((*skb->data) & 1) { |
| /* protocol is compressed */ |
| skb_push(skb, 1)[0] = 0; |
| } |
| |
| skb->ip_summed = CHECKSUM_NONE; |
| skb_set_network_header(skb, skb->head-skb->data); |
| ppp_input(&po->chan, skb); |
| |
| return NET_RX_SUCCESS; |
| } |
| drop: |
| kfree_skb(skb); |
| return NET_RX_DROP; |
| } |
| |
| static int pptp_rcv(struct sk_buff *skb) |
| { |
| struct pppox_sock *po; |
| struct pptp_gre_header *header; |
| struct iphdr *iph; |
| |
| if (skb->pkt_type != PACKET_HOST) |
| goto drop; |
| |
| if (!pskb_may_pull(skb, 12)) |
| goto drop; |
| |
| iph = ip_hdr(skb); |
| |
| header = (struct pptp_gre_header *)skb->data; |
| |
| if (ntohs(header->protocol) != PPTP_GRE_PROTO || /* PPTP-GRE protocol for PPTP */ |
| PPTP_GRE_IS_C(header->flags) || /* flag C should be clear */ |
| PPTP_GRE_IS_R(header->flags) || /* flag R should be clear */ |
| !PPTP_GRE_IS_K(header->flags) || /* flag K should be set */ |
| (header->flags&0xF) != 0) /* routing and recursion ctrl = 0 */ |
| /* if invalid, discard this packet */ |
| goto drop; |
| |
| po = lookup_chan(htons(header->call_id), iph->saddr); |
| if (po) { |
| skb_dst_drop(skb); |
| nf_reset(skb); |
| return sk_receive_skb(sk_pppox(po), skb, 0); |
| } |
| drop: |
| kfree_skb(skb); |
| return NET_RX_DROP; |
| } |
| |
| static int pptp_bind(struct socket *sock, struct sockaddr *uservaddr, |
| int sockaddr_len) |
| { |
| struct sock *sk = sock->sk; |
| struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr; |
| struct pppox_sock *po = pppox_sk(sk); |
| struct pptp_opt *opt = &po->proto.pptp; |
| int error = 0; |
| |
| lock_sock(sk); |
| |
| opt->src_addr = sp->sa_addr.pptp; |
| if (add_chan(po)) |
| error = -EBUSY; |
| |
| release_sock(sk); |
| return error; |
| } |
| |
| static int pptp_connect(struct socket *sock, struct sockaddr *uservaddr, |
| int sockaddr_len, int flags) |
| { |
| struct sock *sk = sock->sk; |
| struct sockaddr_pppox *sp = (struct sockaddr_pppox *) uservaddr; |
| struct pppox_sock *po = pppox_sk(sk); |
| struct pptp_opt *opt = &po->proto.pptp; |
| struct rtable *rt; |
| struct flowi4 fl4; |
| int error = 0; |
| |
| if (sp->sa_protocol != PX_PROTO_PPTP) |
| return -EINVAL; |
| |
| if (lookup_chan_dst(sp->sa_addr.pptp.call_id, sp->sa_addr.pptp.sin_addr.s_addr)) |
| return -EALREADY; |
| |
| lock_sock(sk); |
| /* Check for already bound sockets */ |
| if (sk->sk_state & PPPOX_CONNECTED) { |
| error = -EBUSY; |
| goto end; |
| } |
| |
| /* Check for already disconnected sockets, on attempts to disconnect */ |
| if (sk->sk_state & PPPOX_DEAD) { |
| error = -EALREADY; |
| goto end; |
| } |
| |
| if (!opt->src_addr.sin_addr.s_addr || !sp->sa_addr.pptp.sin_addr.s_addr) { |
| error = -EINVAL; |
| goto end; |
| } |
| |
| po->chan.private = sk; |
| po->chan.ops = &pptp_chan_ops; |
| |
| rt = ip_route_output_ports(&init_net, &fl4, sk, |
| opt->dst_addr.sin_addr.s_addr, |
| opt->src_addr.sin_addr.s_addr, |
| 0, 0, |
| IPPROTO_GRE, RT_CONN_FLAGS(sk), 0); |
| if (IS_ERR(rt)) { |
| error = -EHOSTUNREACH; |
| goto end; |
| } |
| sk_setup_caps(sk, &rt->dst); |
| |
| po->chan.mtu = dst_mtu(&rt->dst); |
| if (!po->chan.mtu) |
| po->chan.mtu = PPP_MTU; |
| ip_rt_put(rt); |
| po->chan.mtu -= PPTP_HEADER_OVERHEAD; |
| |
| po->chan.hdrlen = 2 + sizeof(struct pptp_gre_header); |
| error = ppp_register_channel(&po->chan); |
| if (error) { |
| pr_err("PPTP: failed to register PPP channel (%d)\n", error); |
| goto end; |
| } |
| |
| opt->dst_addr = sp->sa_addr.pptp; |
| sk->sk_state = PPPOX_CONNECTED; |
| |
| end: |
| release_sock(sk); |
| return error; |
| } |
| |
| static int pptp_getname(struct socket *sock, struct sockaddr *uaddr, |
| int *usockaddr_len, int peer) |
| { |
| int len = sizeof(struct sockaddr_pppox); |
| struct sockaddr_pppox sp; |
| |
| sp.sa_family = AF_PPPOX; |
| sp.sa_protocol = PX_PROTO_PPTP; |
| sp.sa_addr.pptp = pppox_sk(sock->sk)->proto.pptp.src_addr; |
| |
| memcpy(uaddr, &sp, len); |
| |
| *usockaddr_len = len; |
| |
| return 0; |
| } |
| |
| static int pptp_release(struct socket *sock) |
| { |
| struct sock *sk = sock->sk; |
| struct pppox_sock *po; |
| struct pptp_opt *opt; |
| int error = 0; |
| |
| if (!sk) |
| return 0; |
| |
| lock_sock(sk); |
| |
| if (sock_flag(sk, SOCK_DEAD)) { |
| release_sock(sk); |
| return -EBADF; |
| } |
| |
| po = pppox_sk(sk); |
| opt = &po->proto.pptp; |
| del_chan(po); |
| |
| pppox_unbind_sock(sk); |
| sk->sk_state = PPPOX_DEAD; |
| |
| sock_orphan(sk); |
| sock->sk = NULL; |
| |
| release_sock(sk); |
| sock_put(sk); |
| |
| return error; |
| } |
| |
| static void pptp_sock_destruct(struct sock *sk) |
| { |
| if (!(sk->sk_state & PPPOX_DEAD)) { |
| del_chan(pppox_sk(sk)); |
| pppox_unbind_sock(sk); |
| } |
| skb_queue_purge(&sk->sk_receive_queue); |
| } |
| |
| static int pptp_create(struct net *net, struct socket *sock) |
| { |
| int error = -ENOMEM; |
| struct sock *sk; |
| struct pppox_sock *po; |
| struct pptp_opt *opt; |
| |
| sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pptp_sk_proto); |
| if (!sk) |
| goto out; |
| |
| sock_init_data(sock, sk); |
| |
| sock->state = SS_UNCONNECTED; |
| sock->ops = &pptp_ops; |
| |
| sk->sk_backlog_rcv = pptp_rcv_core; |
| sk->sk_state = PPPOX_NONE; |
| sk->sk_type = SOCK_STREAM; |
| sk->sk_family = PF_PPPOX; |
| sk->sk_protocol = PX_PROTO_PPTP; |
| sk->sk_destruct = pptp_sock_destruct; |
| |
| po = pppox_sk(sk); |
| opt = &po->proto.pptp; |
| |
| opt->seq_sent = 0; opt->seq_recv = 0; |
| opt->ack_recv = 0; opt->ack_sent = 0; |
| |
| error = 0; |
| out: |
| return error; |
| } |
| |
| static int pptp_ppp_ioctl(struct ppp_channel *chan, unsigned int cmd, |
| unsigned long arg) |
| { |
| struct sock *sk = (struct sock *) chan->private; |
| struct pppox_sock *po = pppox_sk(sk); |
| struct pptp_opt *opt = &po->proto.pptp; |
| void __user *argp = (void __user *)arg; |
| int __user *p = argp; |
| int err, val; |
| |
| err = -EFAULT; |
| switch (cmd) { |
| case PPPIOCGFLAGS: |
| val = opt->ppp_flags; |
| if (put_user(val, p)) |
| break; |
| err = 0; |
| break; |
| case PPPIOCSFLAGS: |
| if (get_user(val, p)) |
| break; |
| opt->ppp_flags = val & ~SC_RCV_BITS; |
| err = 0; |
| break; |
| default: |
| err = -ENOTTY; |
| } |
| |
| return err; |
| } |
| |
| static const struct ppp_channel_ops pptp_chan_ops = { |
| .start_xmit = pptp_xmit, |
| .ioctl = pptp_ppp_ioctl, |
| }; |
| |
| static struct proto pptp_sk_proto __read_mostly = { |
| .name = "PPTP", |
| .owner = THIS_MODULE, |
| .obj_size = sizeof(struct pppox_sock), |
| }; |
| |
| static const struct proto_ops pptp_ops = { |
| .family = AF_PPPOX, |
| .owner = THIS_MODULE, |
| .release = pptp_release, |
| .bind = pptp_bind, |
| .connect = pptp_connect, |
| .socketpair = sock_no_socketpair, |
| .accept = sock_no_accept, |
| .getname = pptp_getname, |
| .poll = sock_no_poll, |
| .listen = sock_no_listen, |
| .shutdown = sock_no_shutdown, |
| .setsockopt = sock_no_setsockopt, |
| .getsockopt = sock_no_getsockopt, |
| .sendmsg = sock_no_sendmsg, |
| .recvmsg = sock_no_recvmsg, |
| .mmap = sock_no_mmap, |
| .ioctl = pppox_ioctl, |
| }; |
| |
| static const struct pppox_proto pppox_pptp_proto = { |
| .create = pptp_create, |
| .owner = THIS_MODULE, |
| }; |
| |
| static const struct gre_protocol gre_pptp_protocol = { |
| .handler = pptp_rcv, |
| }; |
| |
| static int __init pptp_init_module(void) |
| { |
| int err = 0; |
| pr_info("PPTP driver version " PPTP_DRIVER_VERSION "\n"); |
| |
| callid_sock = vzalloc((MAX_CALLID + 1) * sizeof(void *)); |
| if (!callid_sock) { |
| pr_err("PPTP: cann't allocate memory\n"); |
| return -ENOMEM; |
| } |
| |
| err = gre_add_protocol(&gre_pptp_protocol, GREPROTO_PPTP); |
| if (err) { |
| pr_err("PPTP: can't add gre protocol\n"); |
| goto out_mem_free; |
| } |
| |
| err = proto_register(&pptp_sk_proto, 0); |
| if (err) { |
| pr_err("PPTP: can't register sk_proto\n"); |
| goto out_gre_del_protocol; |
| } |
| |
| err = register_pppox_proto(PX_PROTO_PPTP, &pppox_pptp_proto); |
| if (err) { |
| pr_err("PPTP: can't register pppox_proto\n"); |
| goto out_unregister_sk_proto; |
| } |
| |
| return 0; |
| |
| out_unregister_sk_proto: |
| proto_unregister(&pptp_sk_proto); |
| out_gre_del_protocol: |
| gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP); |
| out_mem_free: |
| vfree(callid_sock); |
| |
| return err; |
| } |
| |
| static void __exit pptp_exit_module(void) |
| { |
| unregister_pppox_proto(PX_PROTO_PPTP); |
| proto_unregister(&pptp_sk_proto); |
| gre_del_protocol(&gre_pptp_protocol, GREPROTO_PPTP); |
| vfree(callid_sock); |
| } |
| |
| module_init(pptp_init_module); |
| module_exit(pptp_exit_module); |
| |
| MODULE_DESCRIPTION("Point-to-Point Tunneling Protocol"); |
| MODULE_AUTHOR("D. Kozlov (xeb@mail.ru)"); |
| MODULE_LICENSE("GPL"); |