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-rw-r--r--net/ipv4/ipip.c859
1 files changed, 859 insertions, 0 deletions
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
new file mode 100644
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--- /dev/null
+++ b/net/ipv4/ipip.c
@@ -0,0 +1,859 @@
+/*
+ * Linux NET3: IP/IP protocol decoder.
+ *
+ * Authors:
+ * Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
+ *
+ * Fixes:
+ * Alan Cox : Merged and made usable non modular (its so tiny its silly as
+ * a module taking up 2 pages).
+ * Alan Cox : Fixed bug with 1.3.18 and IPIP not working (now needs to set skb->h.iph)
+ * to keep ip_forward happy.
+ * Alan Cox : More fixes for 1.3.21, and firewall fix. Maybe this will work soon 8).
+ * Kai Schulte : Fixed #defines for IP_FIREWALL->FIREWALL
+ * David Woodhouse : Perform some basic ICMP handling.
+ * IPIP Routing without decapsulation.
+ * Carlos Picoto : GRE over IP support
+ * Alexey Kuznetsov: Reworked. Really, now it is truncated version of ipv4/ip_gre.c.
+ * I do not want to merge them together.
+ *
+ * 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.
+ *
+ */
+
+/* tunnel.c: an IP tunnel driver
+
+ The purpose of this driver is to provide an IP tunnel through
+ which you can tunnel network traffic transparently across subnets.
+
+ This was written by looking at Nick Holloway's dummy driver
+ Thanks for the great code!
+
+ -Sam Lantinga (slouken@cs.ucdavis.edu) 02/01/95
+
+ Minor tweaks:
+ Cleaned up the code a little and added some pre-1.3.0 tweaks.
+ dev->hard_header/hard_header_len changed to use no headers.
+ Comments/bracketing tweaked.
+ Made the tunnels use dev->name not tunnel: when error reporting.
+ Added tx_dropped stat
+
+ -Alan Cox (alan@lxorguk.ukuu.org.uk) 21 March 95
+
+ Reworked:
+ Changed to tunnel to destination gateway in addition to the
+ tunnel's pointopoint address
+ Almost completely rewritten
+ Note: There is currently no firewall or ICMP handling done.
+
+ -Sam Lantinga (slouken@cs.ucdavis.edu) 02/13/96
+
+*/
+
+/* Things I wish I had known when writing the tunnel driver:
+
+ When the tunnel_xmit() function is called, the skb contains the
+ packet to be sent (plus a great deal of extra info), and dev
+ contains the tunnel device that _we_ are.
+
+ When we are passed a packet, we are expected to fill in the
+ source address with our source IP address.
+
+ What is the proper way to allocate, copy and free a buffer?
+ After you allocate it, it is a "0 length" chunk of memory
+ starting at zero. If you want to add headers to the buffer
+ later, you'll have to call "skb_reserve(skb, amount)" with
+ the amount of memory you want reserved. Then, you call
+ "skb_put(skb, amount)" with the amount of space you want in
+ the buffer. skb_put() returns a pointer to the top (#0) of
+ that buffer. skb->len is set to the amount of space you have
+ "allocated" with skb_put(). You can then write up to skb->len
+ bytes to that buffer. If you need more, you can call skb_put()
+ again with the additional amount of space you need. You can
+ find out how much more space you can allocate by calling
+ "skb_tailroom(skb)".
+ Now, to add header space, call "skb_push(skb, header_len)".
+ This creates space at the beginning of the buffer and returns
+ a pointer to this new space. If later you need to strip a
+ header from a buffer, call "skb_pull(skb, header_len)".
+ skb_headroom() will return how much space is left at the top
+ of the buffer (before the main data). Remember, this headroom
+ space must be reserved before the skb_put() function is called.
+ */
+
+/*
+ This version of net/ipv4/ipip.c is cloned of net/ipv4/ip_gre.c
+
+ For comments look at net/ipv4/ip_gre.c --ANK
+ */
+
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <asm/uaccess.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <linux/if_arp.h>
+#include <linux/mroute.h>
+#include <linux/init.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/if_ether.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/ipip.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+
+#define HASH_SIZE 16
+#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+
+static int ipip_net_id;
+struct ipip_net {
+ struct ip_tunnel *tunnels_r_l[HASH_SIZE];
+ struct ip_tunnel *tunnels_r[HASH_SIZE];
+ struct ip_tunnel *tunnels_l[HASH_SIZE];
+ struct ip_tunnel *tunnels_wc[1];
+ struct ip_tunnel **tunnels[4];
+
+ struct net_device *fb_tunnel_dev;
+};
+
+static int ipip_fb_tunnel_init(struct net_device *dev);
+static int ipip_tunnel_init(struct net_device *dev);
+static void ipip_tunnel_setup(struct net_device *dev);
+
+static DEFINE_RWLOCK(ipip_lock);
+
+static struct ip_tunnel * ipip_tunnel_lookup(struct net *net,
+ __be32 remote, __be32 local)
+{
+ unsigned h0 = HASH(remote);
+ unsigned h1 = HASH(local);
+ struct ip_tunnel *t;
+ struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+ for (t = ipn->tunnels_r_l[h0^h1]; t; t = t->next) {
+ if (local == t->parms.iph.saddr &&
+ remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
+ return t;
+ }
+ for (t = ipn->tunnels_r[h0]; t; t = t->next) {
+ if (remote == t->parms.iph.daddr && (t->dev->flags&IFF_UP))
+ return t;
+ }
+ for (t = ipn->tunnels_l[h1]; t; t = t->next) {
+ if (local == t->parms.iph.saddr && (t->dev->flags&IFF_UP))
+ return t;
+ }
+ if ((t = ipn->tunnels_wc[0]) != NULL && (t->dev->flags&IFF_UP))
+ return t;
+ return NULL;
+}
+
+static struct ip_tunnel **__ipip_bucket(struct ipip_net *ipn,
+ struct ip_tunnel_parm *parms)
+{
+ __be32 remote = parms->iph.daddr;
+ __be32 local = parms->iph.saddr;
+ unsigned h = 0;
+ int prio = 0;
+
+ if (remote) {
+ prio |= 2;
+ h ^= HASH(remote);
+ }
+ if (local) {
+ prio |= 1;
+ h ^= HASH(local);
+ }
+ return &ipn->tunnels[prio][h];
+}
+
+static inline struct ip_tunnel **ipip_bucket(struct ipip_net *ipn,
+ struct ip_tunnel *t)
+{
+ return __ipip_bucket(ipn, &t->parms);
+}
+
+static void ipip_tunnel_unlink(struct ipip_net *ipn, struct ip_tunnel *t)
+{
+ struct ip_tunnel **tp;
+
+ for (tp = ipip_bucket(ipn, t); *tp; tp = &(*tp)->next) {
+ if (t == *tp) {
+ write_lock_bh(&ipip_lock);
+ *tp = t->next;
+ write_unlock_bh(&ipip_lock);
+ break;
+ }
+ }
+}
+
+static void ipip_tunnel_link(struct ipip_net *ipn, struct ip_tunnel *t)
+{
+ struct ip_tunnel **tp = ipip_bucket(ipn, t);
+
+ t->next = *tp;
+ write_lock_bh(&ipip_lock);
+ *tp = t;
+ write_unlock_bh(&ipip_lock);
+}
+
+static struct ip_tunnel * ipip_tunnel_locate(struct net *net,
+ struct ip_tunnel_parm *parms, int create)
+{
+ __be32 remote = parms->iph.daddr;
+ __be32 local = parms->iph.saddr;
+ struct ip_tunnel *t, **tp, *nt;
+ struct net_device *dev;
+ char name[IFNAMSIZ];
+ struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+ for (tp = __ipip_bucket(ipn, parms); (t = *tp) != NULL; tp = &t->next) {
+ if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr)
+ return t;
+ }
+ if (!create)
+ return NULL;
+
+ if (parms->name[0])
+ strlcpy(name, parms->name, IFNAMSIZ);
+ else
+ sprintf(name, "tunl%%d");
+
+ dev = alloc_netdev(sizeof(*t), name, ipip_tunnel_setup);
+ if (dev == NULL)
+ return NULL;
+
+ dev_net_set(dev, net);
+
+ if (strchr(name, '%')) {
+ if (dev_alloc_name(dev, name) < 0)
+ goto failed_free;
+ }
+
+ nt = netdev_priv(dev);
+ dev->init = ipip_tunnel_init;
+ nt->parms = *parms;
+
+ if (register_netdevice(dev) < 0)
+ goto failed_free;
+
+ dev_hold(dev);
+ ipip_tunnel_link(ipn, nt);
+ return nt;
+
+failed_free:
+ free_netdev(dev);
+ return NULL;
+}
+
+static void ipip_tunnel_uninit(struct net_device *dev)
+{
+ struct net *net = dev_net(dev);
+ struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+ if (dev == ipn->fb_tunnel_dev) {
+ write_lock_bh(&ipip_lock);
+ ipn->tunnels_wc[0] = NULL;
+ write_unlock_bh(&ipip_lock);
+ } else
+ ipip_tunnel_unlink(ipn, netdev_priv(dev));
+ dev_put(dev);
+}
+
+static int ipip_err(struct sk_buff *skb, u32 info)
+{
+
+/* All the routers (except for Linux) return only
+ 8 bytes of packet payload. It means, that precise relaying of
+ ICMP in the real Internet is absolutely infeasible.
+ */
+ struct iphdr *iph = (struct iphdr*)skb->data;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ struct ip_tunnel *t;
+ int err;
+
+ switch (type) {
+ default:
+ case ICMP_PARAMETERPROB:
+ return 0;
+
+ case ICMP_DEST_UNREACH:
+ switch (code) {
+ case ICMP_SR_FAILED:
+ case ICMP_PORT_UNREACH:
+ /* Impossible event. */
+ return 0;
+ case ICMP_FRAG_NEEDED:
+ /* Soft state for pmtu is maintained by IP core. */
+ return 0;
+ default:
+ /* All others are translated to HOST_UNREACH.
+ rfc2003 contains "deep thoughts" about NET_UNREACH,
+ I believe they are just ether pollution. --ANK
+ */
+ break;
+ }
+ break;
+ case ICMP_TIME_EXCEEDED:
+ if (code != ICMP_EXC_TTL)
+ return 0;
+ break;
+ }
+
+ err = -ENOENT;
+
+ read_lock(&ipip_lock);
+ t = ipip_tunnel_lookup(dev_net(skb->dev), iph->daddr, iph->saddr);
+ if (t == NULL || t->parms.iph.daddr == 0)
+ goto out;
+
+ err = 0;
+ if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+ goto out;
+
+ if (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO)
+ t->err_count++;
+ else
+ t->err_count = 1;
+ t->err_time = jiffies;
+out:
+ read_unlock(&ipip_lock);
+ return err;
+}
+
+static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
+ struct sk_buff *skb)
+{
+ struct iphdr *inner_iph = ip_hdr(skb);
+
+ if (INET_ECN_is_ce(outer_iph->tos))
+ IP_ECN_set_ce(inner_iph);
+}
+
+static int ipip_rcv(struct sk_buff *skb)
+{
+ struct ip_tunnel *tunnel;
+ const struct iphdr *iph = ip_hdr(skb);
+
+ read_lock(&ipip_lock);
+ if ((tunnel = ipip_tunnel_lookup(dev_net(skb->dev),
+ iph->saddr, iph->daddr)) != NULL) {
+ if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) {
+ read_unlock(&ipip_lock);
+ kfree_skb(skb);
+ return 0;
+ }
+
+ secpath_reset(skb);
+
+ skb->mac_header = skb->network_header;
+ skb_reset_network_header(skb);
+ skb->protocol = htons(ETH_P_IP);
+ skb->pkt_type = PACKET_HOST;
+
+ tunnel->dev->stats.rx_packets++;
+ tunnel->dev->stats.rx_bytes += skb->len;
+ skb->dev = tunnel->dev;
+ dst_release(skb->dst);
+ skb->dst = NULL;
+ nf_reset(skb);
+ ipip_ecn_decapsulate(iph, skb);
+ netif_rx(skb);
+ read_unlock(&ipip_lock);
+ return 0;
+ }
+ read_unlock(&ipip_lock);
+
+ return -1;
+}
+
+/*
+ * This function assumes it is being called from dev_queue_xmit()
+ * and that skb is filled properly by that function.
+ */
+
+static int ipip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct net_device_stats *stats = &tunnel->dev->stats;
+ struct iphdr *tiph = &tunnel->parms.iph;
+ u8 tos = tunnel->parms.iph.tos;
+ __be16 df = tiph->frag_off;
+ struct rtable *rt; /* Route to the other host */
+ struct net_device *tdev; /* Device to other host */
+ struct iphdr *old_iph = ip_hdr(skb);
+ struct iphdr *iph; /* Our new IP header */
+ unsigned int max_headroom; /* The extra header space needed */
+ __be32 dst = tiph->daddr;
+ int mtu;
+
+ if (tunnel->recursion++) {
+ stats->collisions++;
+ goto tx_error;
+ }
+
+ if (skb->protocol != htons(ETH_P_IP))
+ goto tx_error;
+
+ if (tos&1)
+ tos = old_iph->tos;
+
+ if (!dst) {
+ /* NBMA tunnel */
+ if ((rt = skb->rtable) == NULL) {
+ stats->tx_fifo_errors++;
+ goto tx_error;
+ }
+ if ((dst = rt->rt_gateway) == 0)
+ goto tx_error_icmp;
+ }
+
+ {
+ struct flowi fl = { .oif = tunnel->parms.link,
+ .nl_u = { .ip4_u =
+ { .daddr = dst,
+ .saddr = tiph->saddr,
+ .tos = RT_TOS(tos) } },
+ .proto = IPPROTO_IPIP };
+ if (ip_route_output_key(dev_net(dev), &rt, &fl)) {
+ stats->tx_carrier_errors++;
+ goto tx_error_icmp;
+ }
+ }
+ tdev = rt->u.dst.dev;
+
+ if (tdev == dev) {
+ ip_rt_put(rt);
+ stats->collisions++;
+ goto tx_error;
+ }
+
+ if (tiph->frag_off)
+ mtu = dst_mtu(&rt->u.dst) - sizeof(struct iphdr);
+ else
+ mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu;
+
+ if (mtu < 68) {
+ stats->collisions++;
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+ if (skb->dst)
+ skb->dst->ops->update_pmtu(skb->dst, mtu);
+
+ df |= (old_iph->frag_off&htons(IP_DF));
+
+ if ((old_iph->frag_off&htons(IP_DF)) && mtu < ntohs(old_iph->tot_len)) {
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu));
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+
+ if (tunnel->err_count > 0) {
+ if (jiffies - tunnel->err_time < IPTUNNEL_ERR_TIMEO) {
+ tunnel->err_count--;
+ dst_link_failure(skb);
+ } else
+ tunnel->err_count = 0;
+ }
+
+ /*
+ * Okay, now see if we can stuff it in the buffer as-is.
+ */
+ max_headroom = (LL_RESERVED_SPACE(tdev)+sizeof(struct iphdr));
+
+ if (skb_headroom(skb) < max_headroom || skb_shared(skb) ||
+ (skb_cloned(skb) && !skb_clone_writable(skb, 0))) {
+ struct sk_buff *new_skb = skb_realloc_headroom(skb, max_headroom);
+ if (!new_skb) {
+ ip_rt_put(rt);
+ stats->tx_dropped++;
+ dev_kfree_skb(skb);
+ tunnel->recursion--;
+ return 0;
+ }
+ if (skb->sk)
+ skb_set_owner_w(new_skb, skb->sk);
+ dev_kfree_skb(skb);
+ skb = new_skb;
+ old_iph = ip_hdr(skb);
+ }
+
+ skb->transport_header = skb->network_header;
+ skb_push(skb, sizeof(struct iphdr));
+ 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);
+ dst_release(skb->dst);
+ skb->dst = &rt->u.dst;
+
+ /*
+ * Push down and install the IPIP header.
+ */
+
+ iph = ip_hdr(skb);
+ iph->version = 4;
+ iph->ihl = sizeof(struct iphdr)>>2;
+ iph->frag_off = df;
+ iph->protocol = IPPROTO_IPIP;
+ iph->tos = INET_ECN_encapsulate(tos, old_iph->tos);
+ iph->daddr = rt->rt_dst;
+ iph->saddr = rt->rt_src;
+
+ if ((iph->ttl = tiph->ttl) == 0)
+ iph->ttl = old_iph->ttl;
+
+ nf_reset(skb);
+
+ IPTUNNEL_XMIT();
+ tunnel->recursion--;
+ return 0;
+
+tx_error_icmp:
+ dst_link_failure(skb);
+tx_error:
+ stats->tx_errors++;
+ dev_kfree_skb(skb);
+ tunnel->recursion--;
+ return 0;
+}
+
+static void ipip_tunnel_bind_dev(struct net_device *dev)
+{
+ struct net_device *tdev = NULL;
+ struct ip_tunnel *tunnel;
+ struct iphdr *iph;
+
+ tunnel = netdev_priv(dev);
+ iph = &tunnel->parms.iph;
+
+ if (iph->daddr) {
+ struct flowi fl = { .oif = tunnel->parms.link,
+ .nl_u = { .ip4_u =
+ { .daddr = iph->daddr,
+ .saddr = iph->saddr,
+ .tos = RT_TOS(iph->tos) } },
+ .proto = IPPROTO_IPIP };
+ struct rtable *rt;
+ if (!ip_route_output_key(dev_net(dev), &rt, &fl)) {
+ tdev = rt->u.dst.dev;
+ ip_rt_put(rt);
+ }
+ dev->flags |= IFF_POINTOPOINT;
+ }
+
+ if (!tdev && tunnel->parms.link)
+ tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+
+ if (tdev) {
+ dev->hard_header_len = tdev->hard_header_len + sizeof(struct iphdr);
+ dev->mtu = tdev->mtu - sizeof(struct iphdr);
+ }
+ dev->iflink = tunnel->parms.link;
+}
+
+static int
+ipip_tunnel_ioctl (struct net_device *dev, struct ifreq *ifr, int cmd)
+{
+ int err = 0;
+ struct ip_tunnel_parm p;
+ struct ip_tunnel *t;
+ struct net *net = dev_net(dev);
+ struct ipip_net *ipn = net_generic(net, ipip_net_id);
+
+ switch (cmd) {
+ case SIOCGETTUNNEL:
+ t = NULL;
+ if (dev == ipn->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+ err = -EFAULT;
+ break;
+ }
+ t = ipip_tunnel_locate(net, &p, 0);
+ }
+ if (t == NULL)
+ t = netdev_priv(dev);
+ memcpy(&p, &t->parms, sizeof(p));
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
+ err = -EFAULT;
+ break;
+
+ case SIOCADDTUNNEL:
+ case SIOCCHGTUNNEL:
+ err = -EPERM;
+ if (!capable(CAP_NET_ADMIN))
+ goto done;
+
+ err = -EFAULT;
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ goto done;
+
+ err = -EINVAL;
+ if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
+ p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)))
+ goto done;
+ if (p.iph.ttl)
+ p.iph.frag_off |= htons(IP_DF);
+
+ t = ipip_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
+
+ if (dev != ipn->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+ if (t != NULL) {
+ if (t->dev != dev) {
+ err = -EEXIST;
+ break;
+ }
+ } else {
+ if (((dev->flags&IFF_POINTOPOINT) && !p.iph.daddr) ||
+ (!(dev->flags&IFF_POINTOPOINT) && p.iph.daddr)) {
+ err = -EINVAL;
+ break;
+ }
+ t = netdev_priv(dev);
+ ipip_tunnel_unlink(ipn, t);
+ t->parms.iph.saddr = p.iph.saddr;
+ t->parms.iph.daddr = p.iph.daddr;
+ memcpy(dev->dev_addr, &p.iph.saddr, 4);
+ memcpy(dev->broadcast, &p.iph.daddr, 4);
+ ipip_tunnel_link(ipn, t);
+ netdev_state_change(dev);
+ }
+ }
+
+ if (t) {
+ err = 0;
+ if (cmd == SIOCCHGTUNNEL) {
+ t->parms.iph.ttl = p.iph.ttl;
+ t->parms.iph.tos = p.iph.tos;
+ t->parms.iph.frag_off = p.iph.frag_off;
+ if (t->parms.link != p.link) {
+ t->parms.link = p.link;
+ ipip_tunnel_bind_dev(dev);
+ netdev_state_change(dev);
+ }
+ }
+ if (copy_to_user(ifr->ifr_ifru.ifru_data, &t->parms, sizeof(p)))
+ err = -EFAULT;
+ } else
+ err = (cmd == SIOCADDTUNNEL ? -ENOBUFS : -ENOENT);
+ break;
+
+ case SIOCDELTUNNEL:
+ err = -EPERM;
+ if (!capable(CAP_NET_ADMIN))
+ goto done;
+
+ if (dev == ipn->fb_tunnel_dev) {
+ err = -EFAULT;
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ goto done;
+ err = -ENOENT;
+ if ((t = ipip_tunnel_locate(net, &p, 0)) == NULL)
+ goto done;
+ err = -EPERM;
+ if (t->dev == ipn->fb_tunnel_dev)
+ goto done;
+ dev = t->dev;
+ }
+ unregister_netdevice(dev);
+ err = 0;
+ break;
+
+ default:
+ err = -EINVAL;
+ }
+
+done:
+ return err;
+}
+
+static int ipip_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+ if (new_mtu < 68 || new_mtu > 0xFFF8 - sizeof(struct iphdr))
+ return -EINVAL;
+ dev->mtu = new_mtu;
+ return 0;
+}
+
+static void ipip_tunnel_setup(struct net_device *dev)
+{
+ dev->uninit = ipip_tunnel_uninit;
+ dev->hard_start_xmit = ipip_tunnel_xmit;
+ dev->do_ioctl = ipip_tunnel_ioctl;
+ dev->change_mtu = ipip_tunnel_change_mtu;
+ dev->destructor = free_netdev;
+
+ dev->type = ARPHRD_TUNNEL;
+ dev->hard_header_len = LL_MAX_HEADER + sizeof(struct iphdr);
+ dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr);
+ dev->flags = IFF_NOARP;
+ dev->iflink = 0;
+ dev->addr_len = 4;
+ dev->features |= NETIF_F_NETNS_LOCAL;
+}
+
+static int ipip_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel;
+
+ tunnel = netdev_priv(dev);
+
+ tunnel->dev = dev;
+ strcpy(tunnel->parms.name, dev->name);
+
+ memcpy(dev->dev_addr, &tunnel->parms.iph.saddr, 4);
+ memcpy(dev->broadcast, &tunnel->parms.iph.daddr, 4);
+
+ ipip_tunnel_bind_dev(dev);
+
+ return 0;
+}
+
+static int ipip_fb_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct iphdr *iph = &tunnel->parms.iph;
+ struct ipip_net *ipn = net_generic(dev_net(dev), ipip_net_id);
+
+ tunnel->dev = dev;
+ strcpy(tunnel->parms.name, dev->name);
+
+ iph->version = 4;
+ iph->protocol = IPPROTO_IPIP;
+ iph->ihl = 5;
+
+ dev_hold(dev);
+ ipn->tunnels_wc[0] = tunnel;
+ return 0;
+}
+
+static struct xfrm_tunnel ipip_handler = {
+ .handler = ipip_rcv,
+ .err_handler = ipip_err,
+ .priority = 1,
+};
+
+static char banner[] __initdata =
+ KERN_INFO "IPv4 over IPv4 tunneling driver\n";
+
+static void ipip_destroy_tunnels(struct ipip_net *ipn)
+{
+ int prio;
+
+ for (prio = 1; prio < 4; prio++) {
+ int h;
+ for (h = 0; h < HASH_SIZE; h++) {
+ struct ip_tunnel *t;
+ while ((t = ipn->tunnels[prio][h]) != NULL)
+ unregister_netdevice(t->dev);
+ }
+ }
+}
+
+static int ipip_init_net(struct net *net)
+{
+ int err;
+ struct ipip_net *ipn;
+
+ err = -ENOMEM;
+ ipn = kzalloc(sizeof(struct ipip_net), GFP_KERNEL);
+ if (ipn == NULL)
+ goto err_alloc;
+
+ err = net_assign_generic(net, ipip_net_id, ipn);
+ if (err < 0)
+ goto err_assign;
+
+ ipn->tunnels[0] = ipn->tunnels_wc;
+ ipn->tunnels[1] = ipn->tunnels_l;
+ ipn->tunnels[2] = ipn->tunnels_r;
+ ipn->tunnels[3] = ipn->tunnels_r_l;
+
+ ipn->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel),
+ "tunl0",
+ ipip_tunnel_setup);
+ if (!ipn->fb_tunnel_dev) {
+ err = -ENOMEM;
+ goto err_alloc_dev;
+ }
+
+ ipn->fb_tunnel_dev->init = ipip_fb_tunnel_init;
+ dev_net_set(ipn->fb_tunnel_dev, net);
+
+ if ((err = register_netdev(ipn->fb_tunnel_dev)))
+ goto err_reg_dev;
+
+ return 0;
+
+err_reg_dev:
+ free_netdev(ipn->fb_tunnel_dev);
+err_alloc_dev:
+ /* nothing */
+err_assign:
+ kfree(ipn);
+err_alloc:
+ return err;
+}
+
+static void ipip_exit_net(struct net *net)
+{
+ struct ipip_net *ipn;
+
+ ipn = net_generic(net, ipip_net_id);
+ rtnl_lock();
+ ipip_destroy_tunnels(ipn);
+ unregister_netdevice(ipn->fb_tunnel_dev);
+ rtnl_unlock();
+ kfree(ipn);
+}
+
+static struct pernet_operations ipip_net_ops = {
+ .init = ipip_init_net,
+ .exit = ipip_exit_net,
+};
+
+static int __init ipip_init(void)
+{
+ int err;
+
+ printk(banner);
+
+ if (xfrm4_tunnel_register(&ipip_handler, AF_INET)) {
+ printk(KERN_INFO "ipip init: can't register tunnel\n");
+ return -EAGAIN;
+ }
+
+ err = register_pernet_gen_device(&ipip_net_id, &ipip_net_ops);
+ if (err)
+ xfrm4_tunnel_deregister(&ipip_handler, AF_INET);
+
+ return err;
+}
+
+static void __exit ipip_fini(void)
+{
+ if (xfrm4_tunnel_deregister(&ipip_handler, AF_INET))
+ printk(KERN_INFO "ipip close: can't deregister tunnel\n");
+
+ unregister_pernet_gen_device(ipip_net_id, &ipip_net_ops);
+}
+
+module_init(ipip_init);
+module_exit(ipip_fini);
+MODULE_LICENSE("GPL");
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