zte's code,first commit
Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/net/ipv4/ip_gre.c b/ap/os/linux/linux-3.4.x/net/ipv4/ip_gre.c
new file mode 100644
index 0000000..a16509c
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/net/ipv4/ip_gre.c
@@ -0,0 +1,1767 @@
+/*
+ * Linux NET3: GRE over IP protocol decoder.
+ *
+ * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.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.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/capability.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.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/in6.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/etherdevice.h>
+#include <linux/if_ether.h>
+
+#include <net/sock.h>
+#include <net/ip.h>
+#include <net/icmp.h>
+#include <net/protocol.h>
+#include <net/ipip.h>
+#include <net/arp.h>
+#include <net/checksum.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <net/xfrm.h>
+#include <net/net_namespace.h>
+#include <net/netns/generic.h>
+#include <net/rtnetlink.h>
+#include <net/gre.h>
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#endif
+
+/*
+ Problems & solutions
+ --------------------
+
+ 1. The most important issue is detecting local dead loops.
+ They would cause complete host lockup in transmit, which
+ would be "resolved" by stack overflow or, if queueing is enabled,
+ with infinite looping in net_bh.
+
+ We cannot track such dead loops during route installation,
+ it is infeasible task. The most general solutions would be
+ to keep skb->encapsulation counter (sort of local ttl),
+ and silently drop packet when it expires. It is a good
+ solution, but it supposes maintaining new variable in ALL
+ skb, even if no tunneling is used.
+
+ Current solution: xmit_recursion breaks dead loops. This is a percpu
+ counter, since when we enter the first ndo_xmit(), cpu migration is
+ forbidden. We force an exit if this counter reaches RECURSION_LIMIT
+
+ 2. Networking dead loops would not kill routers, but would really
+ kill network. IP hop limit plays role of "t->recursion" in this case,
+ if we copy it from packet being encapsulated to upper header.
+ It is very good solution, but it introduces two problems:
+
+ - Routing protocols, using packets with ttl=1 (OSPF, RIP2),
+ do not work over tunnels.
+ - traceroute does not work. I planned to relay ICMP from tunnel,
+ so that this problem would be solved and traceroute output
+ would even more informative. This idea appeared to be wrong:
+ only Linux complies to rfc1812 now (yes, guys, Linux is the only
+ true router now :-)), all routers (at least, in neighbourhood of mine)
+ return only 8 bytes of payload. It is the end.
+
+ Hence, if we want that OSPF worked or traceroute said something reasonable,
+ we should search for another solution.
+
+ One of them is to parse packet trying to detect inner encapsulation
+ made by our node. It is difficult or even impossible, especially,
+ taking into account fragmentation. TO be short, ttl is not solution at all.
+
+ Current solution: The solution was UNEXPECTEDLY SIMPLE.
+ We force DF flag on tunnels with preconfigured hop limit,
+ that is ALL. :-) Well, it does not remove the problem completely,
+ but exponential growth of network traffic is changed to linear
+ (branches, that exceed pmtu are pruned) and tunnel mtu
+ rapidly degrades to value <68, where looping stops.
+ Yes, it is not good if there exists a router in the loop,
+ which does not force DF, even when encapsulating packets have DF set.
+ But it is not our problem! Nobody could accuse us, we made
+ all that we could make. Even if it is your gated who injected
+ fatal route to network, even if it were you who configured
+ fatal static route: you are innocent. :-)
+
+
+
+ 3. Really, ipv4/ipip.c, ipv4/ip_gre.c and ipv6/sit.c contain
+ practically identical code. It would be good to glue them
+ together, but it is not very evident, how to make them modular.
+ sit is integral part of IPv6, ipip and gre are naturally modular.
+ We could extract common parts (hash table, ioctl etc)
+ to a separate module (ip_tunnel.c).
+
+ Alexey Kuznetsov.
+ */
+
+static struct rtnl_link_ops ipgre_link_ops __read_mostly;
+static int ipgre_tunnel_init(struct net_device *dev);
+static void ipgre_tunnel_setup(struct net_device *dev);
+static int ipgre_tunnel_bind_dev(struct net_device *dev);
+
+/* Fallback tunnel: no source, no destination, no key, no options */
+
+#define HASH_SIZE 16
+
+static int ipgre_net_id __read_mostly;
+struct ipgre_net {
+ struct ip_tunnel __rcu *tunnels[4][HASH_SIZE];
+
+ struct net_device *fb_tunnel_dev;
+};
+
+/* Tunnel hash table */
+
+/*
+ 4 hash tables:
+
+ 3: (remote,local)
+ 2: (remote,*)
+ 1: (*,local)
+ 0: (*,*)
+
+ We require exact key match i.e. if a key is present in packet
+ it will match only tunnel with the same key; if it is not present,
+ it will match only keyless tunnel.
+
+ All keysless packets, if not matched configured keyless tunnels
+ will match fallback tunnel.
+ */
+
+#define HASH(addr) (((__force u32)addr^((__force u32)addr>>4))&0xF)
+
+#define tunnels_r_l tunnels[3]
+#define tunnels_r tunnels[2]
+#define tunnels_l tunnels[1]
+#define tunnels_wc tunnels[0]
+/*
+ * Locking : hash tables are protected by RCU and RTNL
+ */
+
+#define for_each_ip_tunnel_rcu(start) \
+ for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
+
+/* often modified stats are per cpu, other are shared (netdev->stats) */
+struct pcpu_tstats {
+ unsigned long rx_packets;
+ unsigned long rx_bytes;
+ unsigned long tx_packets;
+ unsigned long tx_bytes;
+} __attribute__((aligned(4*sizeof(unsigned long))));
+
+static struct net_device_stats *ipgre_get_stats(struct net_device *dev)
+{
+ struct pcpu_tstats sum = { 0 };
+ int i;
+
+ for_each_possible_cpu(i) {
+ const struct pcpu_tstats *tstats = per_cpu_ptr(dev->tstats, i);
+
+ sum.rx_packets += tstats->rx_packets;
+ sum.rx_bytes += tstats->rx_bytes;
+ sum.tx_packets += tstats->tx_packets;
+ sum.tx_bytes += tstats->tx_bytes;
+ }
+ dev->stats.rx_packets = sum.rx_packets;
+ dev->stats.rx_bytes = sum.rx_bytes;
+ dev->stats.tx_packets = sum.tx_packets;
+ dev->stats.tx_bytes = sum.tx_bytes;
+ return &dev->stats;
+}
+
+/* Given src, dst and key, find appropriate for input tunnel. */
+
+static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
+ __be32 remote, __be32 local,
+ __be32 key, __be16 gre_proto)
+{
+ struct net *net = dev_net(dev);
+ int link = dev->ifindex;
+ unsigned int h0 = HASH(remote);
+ unsigned int h1 = HASH(key);
+ struct ip_tunnel *t, *cand = NULL;
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+ int dev_type = (gre_proto == htons(ETH_P_TEB)) ?
+ ARPHRD_ETHER : ARPHRD_IPGRE;
+ int score, cand_score = 4;
+
+ for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
+ if (local != t->parms.iph.saddr ||
+ remote != t->parms.iph.daddr ||
+ key != t->parms.i_key ||
+ !(t->dev->flags & IFF_UP))
+ continue;
+
+ if (t->dev->type != ARPHRD_IPGRE &&
+ t->dev->type != dev_type)
+ continue;
+
+ score = 0;
+ if (t->parms.link != link)
+ score |= 1;
+ if (t->dev->type != dev_type)
+ score |= 2;
+ if (score == 0)
+ return t;
+
+ if (score < cand_score) {
+ cand = t;
+ cand_score = score;
+ }
+ }
+
+ for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
+ if (remote != t->parms.iph.daddr ||
+ key != t->parms.i_key ||
+ !(t->dev->flags & IFF_UP))
+ continue;
+
+ if (t->dev->type != ARPHRD_IPGRE &&
+ t->dev->type != dev_type)
+ continue;
+
+ score = 0;
+ if (t->parms.link != link)
+ score |= 1;
+ if (t->dev->type != dev_type)
+ score |= 2;
+ if (score == 0)
+ return t;
+
+ if (score < cand_score) {
+ cand = t;
+ cand_score = score;
+ }
+ }
+
+ for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
+ if ((local != t->parms.iph.saddr &&
+ (local != t->parms.iph.daddr ||
+ !ipv4_is_multicast(local))) ||
+ key != t->parms.i_key ||
+ !(t->dev->flags & IFF_UP))
+ continue;
+
+ if (t->dev->type != ARPHRD_IPGRE &&
+ t->dev->type != dev_type)
+ continue;
+
+ score = 0;
+ if (t->parms.link != link)
+ score |= 1;
+ if (t->dev->type != dev_type)
+ score |= 2;
+ if (score == 0)
+ return t;
+
+ if (score < cand_score) {
+ cand = t;
+ cand_score = score;
+ }
+ }
+
+ for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
+ if (t->parms.i_key != key ||
+ !(t->dev->flags & IFF_UP))
+ continue;
+
+ if (t->dev->type != ARPHRD_IPGRE &&
+ t->dev->type != dev_type)
+ continue;
+
+ score = 0;
+ if (t->parms.link != link)
+ score |= 1;
+ if (t->dev->type != dev_type)
+ score |= 2;
+ if (score == 0)
+ return t;
+
+ if (score < cand_score) {
+ cand = t;
+ cand_score = score;
+ }
+ }
+
+ if (cand != NULL)
+ return cand;
+
+ dev = ign->fb_tunnel_dev;
+ if (dev->flags & IFF_UP)
+ return netdev_priv(dev);
+
+ return NULL;
+}
+
+static struct ip_tunnel __rcu **__ipgre_bucket(struct ipgre_net *ign,
+ struct ip_tunnel_parm *parms)
+{
+ __be32 remote = parms->iph.daddr;
+ __be32 local = parms->iph.saddr;
+ __be32 key = parms->i_key;
+ unsigned int h = HASH(key);
+ int prio = 0;
+
+ if (local)
+ prio |= 1;
+ if (remote && !ipv4_is_multicast(remote)) {
+ prio |= 2;
+ h ^= HASH(remote);
+ }
+
+ return &ign->tunnels[prio][h];
+}
+
+static inline struct ip_tunnel __rcu **ipgre_bucket(struct ipgre_net *ign,
+ struct ip_tunnel *t)
+{
+ return __ipgre_bucket(ign, &t->parms);
+}
+
+static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
+{
+ struct ip_tunnel __rcu **tp = ipgre_bucket(ign, t);
+
+ rcu_assign_pointer(t->next, rtnl_dereference(*tp));
+ rcu_assign_pointer(*tp, t);
+}
+
+static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
+{
+ struct ip_tunnel __rcu **tp;
+ struct ip_tunnel *iter;
+
+ for (tp = ipgre_bucket(ign, t);
+ (iter = rtnl_dereference(*tp)) != NULL;
+ tp = &iter->next) {
+ if (t == iter) {
+ rcu_assign_pointer(*tp, t->next);
+ break;
+ }
+ }
+}
+
+static struct ip_tunnel *ipgre_tunnel_find(struct net *net,
+ struct ip_tunnel_parm *parms,
+ int type)
+{
+ __be32 remote = parms->iph.daddr;
+ __be32 local = parms->iph.saddr;
+ __be32 key = parms->i_key;
+ int link = parms->link;
+ struct ip_tunnel *t;
+ struct ip_tunnel __rcu **tp;
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+ for (tp = __ipgre_bucket(ign, parms);
+ (t = rtnl_dereference(*tp)) != NULL;
+ tp = &t->next)
+ if (local == t->parms.iph.saddr &&
+ remote == t->parms.iph.daddr &&
+ key == t->parms.i_key &&
+ link == t->parms.link &&
+ type == t->dev->type)
+ break;
+
+ return t;
+}
+
+static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
+ struct ip_tunnel_parm *parms, int create)
+{
+ struct ip_tunnel *t, *nt;
+ struct net_device *dev;
+ char name[IFNAMSIZ];
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+ t = ipgre_tunnel_find(net, parms, ARPHRD_IPGRE);
+ if (t || !create)
+ return t;
+
+ if (parms->name[0])
+ strlcpy(name, parms->name, IFNAMSIZ);
+ else
+ strcpy(name, "gre%d");
+
+ dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
+ if (!dev)
+ return NULL;
+
+ dev_net_set(dev, net);
+
+ nt = netdev_priv(dev);
+ nt->parms = *parms;
+ dev->rtnl_link_ops = &ipgre_link_ops;
+
+ dev->mtu = ipgre_tunnel_bind_dev(dev);
+
+ if (register_netdevice(dev) < 0)
+ goto failed_free;
+
+ /* Can use a lockless transmit, unless we generate output sequences */
+ if (!(nt->parms.o_flags & GRE_SEQ))
+ dev->features |= NETIF_F_LLTX;
+
+ dev_hold(dev);
+ ipgre_tunnel_link(ign, nt);
+ return nt;
+
+failed_free:
+ free_netdev(dev);
+ return NULL;
+}
+
+static void ipgre_tunnel_uninit(struct net_device *dev)
+{
+ struct net *net = dev_net(dev);
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+ ipgre_tunnel_unlink(ign, netdev_priv(dev));
+ dev_put(dev);
+}
+
+
+static void ipgre_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.
+
+ Moreover, Cisco "wise men" put GRE key to the third word
+ in GRE header. It makes impossible maintaining even soft state for keyed
+ GRE tunnels with enabled checksum. Tell them "thank you".
+
+ Well, I wonder, rfc1812 was written by Cisco employee,
+ what the hell these idiots break standards established
+ by themselves???
+ */
+
+ const struct iphdr *iph = (const struct iphdr *)skb->data;
+ __be16 *p = (__be16*)(skb->data+(iph->ihl<<2));
+ int grehlen = (iph->ihl<<2) + 4;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ struct ip_tunnel *t;
+ __be16 flags;
+
+ flags = p[0];
+ if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
+ if (flags&(GRE_VERSION|GRE_ROUTING))
+ return;
+ if (flags&GRE_KEY) {
+ grehlen += 4;
+ if (flags&GRE_CSUM)
+ grehlen += 4;
+ }
+ }
+
+ /* If only 8 bytes returned, keyed message will be dropped here */
+ if (skb_headlen(skb) < grehlen)
+ return;
+
+ switch (type) {
+ default:
+ case ICMP_PARAMETERPROB:
+ return;
+
+ case ICMP_DEST_UNREACH:
+ switch (code) {
+ case ICMP_SR_FAILED:
+ case ICMP_PORT_UNREACH:
+ /* Impossible event. */
+ return;
+ case ICMP_FRAG_NEEDED:
+ /* Soft state for pmtu is maintained by IP core. */
+ return;
+ 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;
+ break;
+ }
+
+ rcu_read_lock();
+ t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
+ flags & GRE_KEY ?
+ *(((__be32 *)p) + (grehlen / 4) - 1) : 0,
+ p[1]);
+ if (t == NULL || t->parms.iph.daddr == 0 ||
+ ipv4_is_multicast(t->parms.iph.daddr))
+ goto out;
+
+ if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+ goto out;
+
+ if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
+ t->err_count++;
+ else
+ t->err_count = 1;
+ t->err_time = jiffies;
+out:
+ rcu_read_unlock();
+}
+
+static inline void ipgre_ecn_decapsulate(const struct iphdr *iph, struct sk_buff *skb)
+{
+ if (INET_ECN_is_ce(iph->tos)) {
+ if (skb->protocol == htons(ETH_P_IP)) {
+ IP_ECN_set_ce(ip_hdr(skb));
+ } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ IP6_ECN_set_ce(ipv6_hdr(skb));
+ }
+ }
+}
+
+static inline u8
+ipgre_ecn_encapsulate(u8 tos, const struct iphdr *old_iph, struct sk_buff *skb)
+{
+ u8 inner = 0;
+ if (skb->protocol == htons(ETH_P_IP))
+ inner = old_iph->tos;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ inner = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
+ return INET_ECN_encapsulate(tos, inner);
+}
+
+static int ipgre_rcv(struct sk_buff *skb)
+{
+ const struct iphdr *iph;
+ u8 *h;
+ __be16 flags;
+ __sum16 csum = 0;
+ __be32 key = 0;
+ u32 seqno = 0;
+ struct ip_tunnel *tunnel;
+ int offset = 4;
+ __be16 gre_proto;
+
+ if (!pskb_may_pull(skb, 16))
+ goto drop_nolock;
+
+ iph = ip_hdr(skb);
+ h = skb->data;
+ flags = *(__be16*)h;
+
+ if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
+ /* - Version must be 0.
+ - We do not support routing headers.
+ */
+ if (flags&(GRE_VERSION|GRE_ROUTING))
+ goto drop_nolock;
+
+ if (flags&GRE_CSUM) {
+ switch (skb->ip_summed) {
+ case CHECKSUM_COMPLETE:
+ csum = csum_fold(skb->csum);
+ if (!csum)
+ break;
+ /* fall through */
+ case CHECKSUM_NONE:
+ skb->csum = 0;
+ csum = __skb_checksum_complete(skb);
+ skb->ip_summed = CHECKSUM_COMPLETE;
+ }
+ offset += 4;
+ }
+ if (flags&GRE_KEY) {
+ key = *(__be32*)(h + offset);
+ offset += 4;
+ }
+ if (flags&GRE_SEQ) {
+ seqno = ntohl(*(__be32*)(h + offset));
+ offset += 4;
+ }
+ }
+
+ gre_proto = *(__be16 *)(h + 2);
+
+ rcu_read_lock();
+ if ((tunnel = ipgre_tunnel_lookup(skb->dev,
+ iph->saddr, iph->daddr, key,
+ gre_proto))) {
+ struct pcpu_tstats *tstats;
+
+ secpath_reset(skb);
+
+ skb->protocol = gre_proto;
+ /* WCCP version 1 and 2 protocol decoding.
+ * - Change protocol to IP
+ * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
+ */
+ if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
+ skb->protocol = htons(ETH_P_IP);
+ if ((*(h + offset) & 0xF0) != 0x40)
+ offset += 4;
+ }
+
+ skb->mac_header = skb->network_header;
+ __pskb_pull(skb, offset);
+ skb_postpull_rcsum(skb, skb_transport_header(skb), offset);
+ skb->pkt_type = PACKET_HOST;
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ if (ipv4_is_multicast(iph->daddr)) {
+ /* Looped back packet, drop it! */
+ if (rt_is_output_route(skb_rtable(skb)))
+ goto drop;
+ tunnel->dev->stats.multicast++;
+ skb->pkt_type = PACKET_BROADCAST;
+ }
+#endif
+
+ if (((flags&GRE_CSUM) && csum) ||
+ (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
+ tunnel->dev->stats.rx_crc_errors++;
+ tunnel->dev->stats.rx_errors++;
+ goto drop;
+ }
+ if (tunnel->parms.i_flags&GRE_SEQ) {
+ if (!(flags&GRE_SEQ) ||
+ (tunnel->i_seqno && (s32)(seqno - tunnel->i_seqno) < 0)) {
+ tunnel->dev->stats.rx_fifo_errors++;
+ tunnel->dev->stats.rx_errors++;
+ goto drop;
+ }
+ tunnel->i_seqno = seqno + 1;
+ }
+
+ /* Warning: All skb pointers will be invalidated! */
+ if (tunnel->dev->type == ARPHRD_ETHER) {
+ if (!pskb_may_pull(skb, ETH_HLEN)) {
+ tunnel->dev->stats.rx_length_errors++;
+ tunnel->dev->stats.rx_errors++;
+ goto drop;
+ }
+
+ iph = ip_hdr(skb);
+ skb->protocol = eth_type_trans(skb, tunnel->dev);
+ skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+ }
+
+ tstats = this_cpu_ptr(tunnel->dev->tstats);
+ tstats->rx_packets++;
+ tstats->rx_bytes += skb->len;
+
+ __skb_tunnel_rx(skb, tunnel->dev);
+
+ skb_reset_network_header(skb);
+ ipgre_ecn_decapsulate(iph, skb);
+
+ netif_rx(skb);
+
+ rcu_read_unlock();
+ return 0;
+ }
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+
+drop:
+ rcu_read_unlock();
+drop_nolock:
+ kfree_skb(skb);
+ return 0;
+}
+
+static netdev_tx_t ipgre_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct pcpu_tstats *tstats;
+ const struct iphdr *old_iph = ip_hdr(skb);
+ const struct iphdr *tiph;
+ struct flowi4 fl4;
+ u8 tos;
+ __be16 df;
+ struct rtable *rt; /* Route to the other host */
+ struct net_device *tdev; /* Device to other host */
+ struct iphdr *iph; /* Our new IP header */
+ unsigned int max_headroom; /* The extra header space needed */
+ int gre_hlen;
+ __be32 dst;
+ int mtu;
+
+ if (dev->type == ARPHRD_ETHER)
+ IPCB(skb)->flags = 0;
+
+ if (dev->header_ops && dev->type == ARPHRD_IPGRE) {
+ gre_hlen = 0;
+ tiph = (const struct iphdr *)skb->data;
+ } else {
+ gre_hlen = tunnel->hlen;
+ tiph = &tunnel->parms.iph;
+ }
+
+ memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
+ if ((dst = tiph->daddr) == 0) {
+ /* NBMA tunnel */
+
+ if (skb_dst(skb) == NULL) {
+ dev->stats.tx_fifo_errors++;
+ goto tx_error;
+ }
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ rt = skb_rtable(skb);
+ dst = rt->rt_gateway;
+ }
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (skb->protocol == htons(ETH_P_IPV6)) {
+ const struct in6_addr *addr6;
+ struct neighbour *neigh;
+ bool do_tx_error_icmp;
+ int addr_type;
+
+ neigh = dst_neigh_lookup(skb_dst(skb), &ipv6_hdr(skb)->daddr);
+ if (neigh == NULL)
+ goto tx_error;
+
+ addr6 = (const struct in6_addr *)&neigh->primary_key;
+ addr_type = ipv6_addr_type(addr6);
+
+ if (addr_type == IPV6_ADDR_ANY) {
+ addr6 = &ipv6_hdr(skb)->daddr;
+ addr_type = ipv6_addr_type(addr6);
+ }
+
+ if ((addr_type & IPV6_ADDR_COMPATv4) == 0)
+ do_tx_error_icmp = true;
+ else {
+ do_tx_error_icmp = false;
+ dst = addr6->s6_addr32[3];
+ }
+ neigh_release(neigh);
+ if (do_tx_error_icmp)
+ goto tx_error_icmp;
+ }
+#endif
+ else
+ goto tx_error;
+ }
+
+ tos = tiph->tos;
+ if (tos == 1) {
+ tos = 0;
+ if (skb->protocol == htons(ETH_P_IP))
+ tos = old_iph->tos;
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ tos = ipv6_get_dsfield((const struct ipv6hdr *)old_iph);
+ }
+
+ rt = ip_route_output_gre(dev_net(dev), &fl4, dst, tiph->saddr,
+ tunnel->parms.o_key, RT_TOS(tos),
+ tunnel->parms.link);
+ if (IS_ERR(rt)) {
+ dev->stats.tx_carrier_errors++;
+ goto tx_error;
+ }
+ tdev = rt->dst.dev;
+
+ if (tdev == dev) {
+ ip_rt_put(rt);
+ dev->stats.collisions++;
+ goto tx_error;
+ }
+
+ df = tiph->frag_off;
+ if (df)
+ mtu = dst_mtu(&rt->dst) - dev->hard_header_len - tunnel->hlen;
+ else
+ mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
+
+ if (skb_dst(skb))
+ skb_dst(skb)->ops->update_pmtu(skb_dst(skb), mtu);
+
+ if (skb->protocol == htons(ETH_P_IP)) {
+ 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 IS_ENABLED(CONFIG_IPV6)
+ else if (skb->protocol == htons(ETH_P_IPV6)) {
+ struct rt6_info *rt6 = (struct rt6_info *)skb_dst(skb);
+
+ if (rt6 && mtu < dst_mtu(skb_dst(skb)) && mtu >= IPV6_MIN_MTU) {
+ if ((tunnel->parms.iph.daddr &&
+ !ipv4_is_multicast(tunnel->parms.iph.daddr)) ||
+ rt6->rt6i_dst.plen == 128) {
+ rt6->rt6i_flags |= RTF_MODIFIED;
+ dst_metric_set(skb_dst(skb), RTAX_MTU, mtu);
+ }
+ }
+
+ if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) {
+ icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ ip_rt_put(rt);
+ goto tx_error;
+ }
+ }
+#endif
+
+ if (tunnel->err_count > 0) {
+ if (time_before(jiffies,
+ tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
+ tunnel->err_count--;
+
+ dst_link_failure(skb);
+ } else
+ tunnel->err_count = 0;
+ }
+
+ max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen + rt->dst.header_len;
+
+ 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 (max_headroom > dev->needed_headroom)
+ dev->needed_headroom = max_headroom;
+ if (!new_skb) {
+ ip_rt_put(rt);
+ dev->stats.tx_dropped++;
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+ if (skb->sk)
+ skb_set_owner_w(new_skb, skb->sk);
+ dev_kfree_skb(skb);
+ skb = new_skb;
+ old_iph = ip_hdr(skb);
+ }
+
+ skb_reset_transport_header(skb);
+ skb_push(skb, gre_hlen);
+ skb_reset_network_header(skb);
+ IPCB(skb)->flags &= ~(IPSKB_XFRM_TUNNEL_SIZE | IPSKB_XFRM_TRANSFORMED |
+ IPSKB_REROUTED);
+ skb_dst_drop(skb);
+ skb_dst_set(skb, &rt->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_GRE;
+ iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb);
+ iph->daddr = fl4.daddr;
+ iph->saddr = fl4.saddr;
+
+ if ((iph->ttl = tiph->ttl) == 0) {
+ if (skb->protocol == htons(ETH_P_IP))
+ iph->ttl = old_iph->ttl;
+#if IS_ENABLED(CONFIG_IPV6)
+ else if (skb->protocol == htons(ETH_P_IPV6))
+ iph->ttl = ((const struct ipv6hdr *)old_iph)->hop_limit;
+#endif
+ else
+ iph->ttl = ip4_dst_hoplimit(&rt->dst);
+ }
+
+ ((__be16 *)(iph + 1))[0] = tunnel->parms.o_flags;
+ ((__be16 *)(iph + 1))[1] = (dev->type == ARPHRD_ETHER) ?
+ htons(ETH_P_TEB) : skb->protocol;
+
+ if (tunnel->parms.o_flags&(GRE_KEY|GRE_CSUM|GRE_SEQ)) {
+ __be32 *ptr = (__be32*)(((u8*)iph) + tunnel->hlen - 4);
+
+ if (tunnel->parms.o_flags&GRE_SEQ) {
+ ++tunnel->o_seqno;
+ *ptr = htonl(tunnel->o_seqno);
+ ptr--;
+ }
+ if (tunnel->parms.o_flags&GRE_KEY) {
+ *ptr = tunnel->parms.o_key;
+ ptr--;
+ }
+ if (tunnel->parms.o_flags&GRE_CSUM) {
+ *ptr = 0;
+ *(__sum16*)ptr = ip_compute_csum((void*)(iph+1), skb->len - sizeof(struct iphdr));
+ }
+ }
+
+ nf_reset(skb);
+ tstats = this_cpu_ptr(dev->tstats);
+ __IPTUNNEL_XMIT(tstats, &dev->stats);
+ return NETDEV_TX_OK;
+
+#if IS_ENABLED(CONFIG_IPV6)
+tx_error_icmp:
+ dst_link_failure(skb);
+#endif
+tx_error:
+ dev->stats.tx_errors++;
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static int ipgre_tunnel_bind_dev(struct net_device *dev)
+{
+ struct net_device *tdev = NULL;
+ struct ip_tunnel *tunnel;
+ const struct iphdr *iph;
+ int hlen = LL_MAX_HEADER;
+ int mtu = ETH_DATA_LEN;
+ int addend = sizeof(struct iphdr) + 4;
+
+ tunnel = netdev_priv(dev);
+ iph = &tunnel->parms.iph;
+
+ /* Guess output device to choose reasonable mtu and needed_headroom */
+
+ if (iph->daddr) {
+ struct flowi4 fl4;
+ struct rtable *rt;
+
+ rt = ip_route_output_gre(dev_net(dev), &fl4,
+ iph->daddr, iph->saddr,
+ tunnel->parms.o_key,
+ RT_TOS(iph->tos),
+ tunnel->parms.link);
+ if (!IS_ERR(rt)) {
+ tdev = rt->dst.dev;
+ ip_rt_put(rt);
+ }
+
+ if (dev->type != ARPHRD_ETHER)
+ dev->flags |= IFF_POINTOPOINT;
+ }
+
+ if (!tdev && tunnel->parms.link)
+ tdev = __dev_get_by_index(dev_net(dev), tunnel->parms.link);
+
+ if (tdev) {
+ hlen = tdev->hard_header_len + tdev->needed_headroom;
+ mtu = tdev->mtu;
+ }
+ dev->iflink = tunnel->parms.link;
+
+ /* Precalculate GRE options length */
+ if (tunnel->parms.o_flags&(GRE_CSUM|GRE_KEY|GRE_SEQ)) {
+ if (tunnel->parms.o_flags&GRE_CSUM)
+ addend += 4;
+ if (tunnel->parms.o_flags&GRE_KEY)
+ addend += 4;
+ if (tunnel->parms.o_flags&GRE_SEQ)
+ addend += 4;
+ }
+ dev->needed_headroom = addend + hlen;
+ mtu -= dev->hard_header_len + addend;
+
+ if (mtu < 68)
+ mtu = 68;
+
+ tunnel->hlen = addend;
+
+ return mtu;
+}
+
+static int
+ipgre_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 ipgre_net *ign = net_generic(net, ipgre_net_id);
+
+ switch (cmd) {
+ case SIOCGETTUNNEL:
+ t = NULL;
+ if (dev == ign->fb_tunnel_dev) {
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) {
+ err = -EFAULT;
+ break;
+ }
+ t = ipgre_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_GRE ||
+ p.iph.ihl != 5 || (p.iph.frag_off&htons(~IP_DF)) ||
+ ((p.i_flags|p.o_flags)&(GRE_VERSION|GRE_ROUTING)))
+ goto done;
+ if (p.iph.ttl)
+ p.iph.frag_off |= htons(IP_DF);
+
+ if (!(p.i_flags&GRE_KEY))
+ p.i_key = 0;
+ if (!(p.o_flags&GRE_KEY))
+ p.o_key = 0;
+
+ t = ipgre_tunnel_locate(net, &p, cmd == SIOCADDTUNNEL);
+
+ if (dev != ign->fb_tunnel_dev && cmd == SIOCCHGTUNNEL) {
+ if (t != NULL) {
+ if (t->dev != dev) {
+ err = -EEXIST;
+ break;
+ }
+ } else {
+ unsigned int nflags = 0;
+
+ t = netdev_priv(dev);
+
+ if (ipv4_is_multicast(p.iph.daddr))
+ nflags = IFF_BROADCAST;
+ else if (p.iph.daddr)
+ nflags = IFF_POINTOPOINT;
+
+ if ((dev->flags^nflags)&(IFF_POINTOPOINT|IFF_BROADCAST)) {
+ err = -EINVAL;
+ break;
+ }
+ ipgre_tunnel_unlink(ign, t);
+ synchronize_net();
+ t->parms.iph.saddr = p.iph.saddr;
+ t->parms.iph.daddr = p.iph.daddr;
+ t->parms.i_key = p.i_key;
+ t->parms.o_key = p.o_key;
+ memcpy(dev->dev_addr, &p.iph.saddr, 4);
+ memcpy(dev->broadcast, &p.iph.daddr, 4);
+ ipgre_tunnel_link(ign, 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;
+ dev->mtu = ipgre_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 == ign->fb_tunnel_dev) {
+ err = -EFAULT;
+ if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
+ goto done;
+ err = -ENOENT;
+ if ((t = ipgre_tunnel_locate(net, &p, 0)) == NULL)
+ goto done;
+ err = -EPERM;
+ if (t == netdev_priv(ign->fb_tunnel_dev))
+ goto done;
+ dev = t->dev;
+ }
+ unregister_netdevice(dev);
+ err = 0;
+ break;
+
+ default:
+ err = -EINVAL;
+ }
+
+done:
+ return err;
+}
+
+static int ipgre_tunnel_change_mtu(struct net_device *dev, int new_mtu)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ if (new_mtu < 68 ||
+ new_mtu > 0xFFF8 - dev->hard_header_len - tunnel->hlen)
+ return -EINVAL;
+ dev->mtu = new_mtu;
+ return 0;
+}
+
+/* Nice toy. Unfortunately, useless in real life :-)
+ It allows to construct virtual multiprotocol broadcast "LAN"
+ over the Internet, provided multicast routing is tuned.
+
+
+ I have no idea was this bicycle invented before me,
+ so that I had to set ARPHRD_IPGRE to a random value.
+ I have an impression, that Cisco could make something similar,
+ but this feature is apparently missing in IOS<=11.2(8).
+
+ I set up 10.66.66/24 and fec0:6666:6666::0/96 as virtual networks
+ with broadcast 224.66.66.66. If you have access to mbone, play with me :-)
+
+ ping -t 255 224.66.66.66
+
+ If nobody answers, mbone does not work.
+
+ ip tunnel add Universe mode gre remote 224.66.66.66 local <Your_real_addr> ttl 255
+ ip addr add 10.66.66.<somewhat>/24 dev Universe
+ ifconfig Universe up
+ ifconfig Universe add fe80::<Your_real_addr>/10
+ ifconfig Universe add fec0:6666:6666::<Your_real_addr>/96
+ ftp 10.66.66.66
+ ...
+ ftp fec0:6666:6666::193.233.7.65
+ ...
+
+ */
+
+static int ipgre_header(struct sk_buff *skb, struct net_device *dev,
+ unsigned short type,
+ const void *daddr, const void *saddr, unsigned int len)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct iphdr *iph = (struct iphdr *)skb_push(skb, t->hlen);
+ __be16 *p = (__be16*)(iph+1);
+
+ memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
+ p[0] = t->parms.o_flags;
+ p[1] = htons(type);
+
+ /*
+ * Set the source hardware address.
+ */
+
+ if (saddr)
+ memcpy(&iph->saddr, saddr, 4);
+ if (daddr)
+ memcpy(&iph->daddr, daddr, 4);
+ if (iph->daddr)
+ return t->hlen;
+
+ return -t->hlen;
+}
+
+static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr)
+{
+ const struct iphdr *iph = (const struct iphdr *) skb_mac_header(skb);
+ memcpy(haddr, &iph->saddr, 4);
+ return 4;
+}
+
+static const struct header_ops ipgre_header_ops = {
+ .create = ipgre_header,
+ .parse = ipgre_header_parse,
+};
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+static int ipgre_open(struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ if (ipv4_is_multicast(t->parms.iph.daddr)) {
+ struct flowi4 fl4;
+ struct rtable *rt;
+
+ rt = ip_route_output_gre(dev_net(dev), &fl4,
+ t->parms.iph.daddr,
+ t->parms.iph.saddr,
+ t->parms.o_key,
+ RT_TOS(t->parms.iph.tos),
+ t->parms.link);
+ if (IS_ERR(rt))
+ return -EADDRNOTAVAIL;
+ dev = rt->dst.dev;
+ ip_rt_put(rt);
+ if (__in_dev_get_rtnl(dev) == NULL)
+ return -EADDRNOTAVAIL;
+ t->mlink = dev->ifindex;
+ ip_mc_inc_group(__in_dev_get_rtnl(dev), t->parms.iph.daddr);
+ }
+ return 0;
+}
+
+static int ipgre_close(struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
+ struct in_device *in_dev;
+ in_dev = inetdev_by_index(dev_net(dev), t->mlink);
+ if (in_dev)
+ ip_mc_dec_group(in_dev, t->parms.iph.daddr);
+ }
+ return 0;
+}
+
+#endif
+
+static const struct net_device_ops ipgre_netdev_ops = {
+ .ndo_init = ipgre_tunnel_init,
+ .ndo_uninit = ipgre_tunnel_uninit,
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ .ndo_open = ipgre_open,
+ .ndo_stop = ipgre_close,
+#endif
+ .ndo_start_xmit = ipgre_tunnel_xmit,
+ .ndo_do_ioctl = ipgre_tunnel_ioctl,
+ .ndo_change_mtu = ipgre_tunnel_change_mtu,
+ .ndo_get_stats = ipgre_get_stats,
+};
+
+static void ipgre_dev_free(struct net_device *dev)
+{
+ free_percpu(dev->tstats);
+ free_netdev(dev);
+}
+
+static void ipgre_tunnel_setup(struct net_device *dev)
+{
+ dev->netdev_ops = &ipgre_netdev_ops;
+ dev->destructor = ipgre_dev_free;
+
+ dev->type = ARPHRD_IPGRE;
+ dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + 4;
+ dev->mtu = ETH_DATA_LEN - sizeof(struct iphdr) - 4;
+ dev->flags = IFF_NOARP;
+ dev->iflink = 0;
+ dev->addr_len = 4;
+ dev->features |= NETIF_F_NETNS_LOCAL;
+ dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
+}
+
+static int ipgre_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel;
+ struct iphdr *iph;
+
+ tunnel = netdev_priv(dev);
+ iph = &tunnel->parms.iph;
+
+ 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);
+
+ if (iph->daddr) {
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ if (ipv4_is_multicast(iph->daddr)) {
+ if (!iph->saddr)
+ return -EINVAL;
+ dev->flags = IFF_BROADCAST;
+ dev->header_ops = &ipgre_header_ops;
+ }
+#endif
+ } else
+ dev->header_ops = &ipgre_header_ops;
+
+ dev->tstats = alloc_percpu(struct pcpu_tstats);
+ if (!dev->tstats)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static void ipgre_fb_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct iphdr *iph = &tunnel->parms.iph;
+
+ tunnel->dev = dev;
+ strcpy(tunnel->parms.name, dev->name);
+
+ iph->version = 4;
+ iph->protocol = IPPROTO_GRE;
+ iph->ihl = 5;
+ tunnel->hlen = sizeof(struct iphdr) + 4;
+
+ dev_hold(dev);
+}
+
+
+static const struct gre_protocol ipgre_protocol = {
+ .handler = ipgre_rcv,
+ .err_handler = ipgre_err,
+};
+
+static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
+{
+ int prio;
+
+ for (prio = 0; prio < 4; prio++) {
+ int h;
+ for (h = 0; h < HASH_SIZE; h++) {
+ struct ip_tunnel *t;
+
+ t = rtnl_dereference(ign->tunnels[prio][h]);
+
+ while (t != NULL) {
+ unregister_netdevice_queue(t->dev, head);
+ t = rtnl_dereference(t->next);
+ }
+ }
+ }
+}
+
+static int __net_init ipgre_init_net(struct net *net)
+{
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+ int err;
+
+ ign->fb_tunnel_dev = alloc_netdev(sizeof(struct ip_tunnel), "gre0",
+ ipgre_tunnel_setup);
+ if (!ign->fb_tunnel_dev) {
+ err = -ENOMEM;
+ goto err_alloc_dev;
+ }
+ dev_net_set(ign->fb_tunnel_dev, net);
+
+ ipgre_fb_tunnel_init(ign->fb_tunnel_dev);
+ ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops;
+
+ if ((err = register_netdev(ign->fb_tunnel_dev)))
+ goto err_reg_dev;
+
+ rcu_assign_pointer(ign->tunnels_wc[0],
+ netdev_priv(ign->fb_tunnel_dev));
+ return 0;
+
+err_reg_dev:
+ ipgre_dev_free(ign->fb_tunnel_dev);
+err_alloc_dev:
+ return err;
+}
+
+static void __net_exit ipgre_exit_net(struct net *net)
+{
+ struct ipgre_net *ign;
+ LIST_HEAD(list);
+
+ ign = net_generic(net, ipgre_net_id);
+ rtnl_lock();
+ ipgre_destroy_tunnels(ign, &list);
+ unregister_netdevice_many(&list);
+ rtnl_unlock();
+}
+
+static struct pernet_operations ipgre_net_ops = {
+ .init = ipgre_init_net,
+ .exit = ipgre_exit_net,
+ .id = &ipgre_net_id,
+ .size = sizeof(struct ipgre_net),
+};
+
+static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ __be16 flags;
+
+ if (!data)
+ return 0;
+
+ flags = 0;
+ if (data[IFLA_GRE_IFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+ if (data[IFLA_GRE_OFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+ if (flags & (GRE_VERSION|GRE_ROUTING))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ __be32 daddr;
+
+ if (tb[IFLA_ADDRESS]) {
+ if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
+ return -EINVAL;
+ if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
+ return -EADDRNOTAVAIL;
+ }
+
+ if (!data)
+ goto out;
+
+ if (data[IFLA_GRE_REMOTE]) {
+ memcpy(&daddr, nla_data(data[IFLA_GRE_REMOTE]), 4);
+ if (!daddr)
+ return -EINVAL;
+ }
+
+out:
+ return ipgre_tunnel_validate(tb, data);
+}
+
+static void ipgre_netlink_parms(struct nlattr *data[],
+ struct ip_tunnel_parm *parms)
+{
+ memset(parms, 0, sizeof(*parms));
+
+ parms->iph.protocol = IPPROTO_GRE;
+
+ if (!data)
+ return;
+
+ if (data[IFLA_GRE_LINK])
+ parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
+
+ if (data[IFLA_GRE_IFLAGS])
+ parms->i_flags = nla_get_be16(data[IFLA_GRE_IFLAGS]);
+
+ if (data[IFLA_GRE_OFLAGS])
+ parms->o_flags = nla_get_be16(data[IFLA_GRE_OFLAGS]);
+
+ if (data[IFLA_GRE_IKEY])
+ parms->i_key = nla_get_be32(data[IFLA_GRE_IKEY]);
+
+ if (data[IFLA_GRE_OKEY])
+ parms->o_key = nla_get_be32(data[IFLA_GRE_OKEY]);
+
+ if (data[IFLA_GRE_LOCAL])
+ parms->iph.saddr = nla_get_be32(data[IFLA_GRE_LOCAL]);
+
+ if (data[IFLA_GRE_REMOTE])
+ parms->iph.daddr = nla_get_be32(data[IFLA_GRE_REMOTE]);
+
+ if (data[IFLA_GRE_TTL])
+ parms->iph.ttl = nla_get_u8(data[IFLA_GRE_TTL]);
+
+ if (data[IFLA_GRE_TOS])
+ parms->iph.tos = nla_get_u8(data[IFLA_GRE_TOS]);
+
+ if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC]))
+ parms->iph.frag_off = htons(IP_DF);
+}
+
+static int ipgre_tap_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel;
+
+ tunnel = netdev_priv(dev);
+
+ tunnel->dev = dev;
+ strcpy(tunnel->parms.name, dev->name);
+
+ ipgre_tunnel_bind_dev(dev);
+
+ dev->tstats = alloc_percpu(struct pcpu_tstats);
+ if (!dev->tstats)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static const struct net_device_ops ipgre_tap_netdev_ops = {
+ .ndo_init = ipgre_tap_init,
+ .ndo_uninit = ipgre_tunnel_uninit,
+ .ndo_start_xmit = ipgre_tunnel_xmit,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_change_mtu = ipgre_tunnel_change_mtu,
+ .ndo_get_stats = ipgre_get_stats,
+};
+
+static void ipgre_tap_setup(struct net_device *dev)
+{
+
+ ether_setup(dev);
+
+ dev->netdev_ops = &ipgre_tap_netdev_ops;
+ dev->destructor = ipgre_dev_free;
+
+ dev->iflink = 0;
+ dev->features |= NETIF_F_NETNS_LOCAL;
+}
+
+static int ipgre_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[],
+ struct nlattr *data[])
+{
+ struct ip_tunnel *nt;
+ struct net *net = dev_net(dev);
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+ int mtu;
+ int err;
+
+ nt = netdev_priv(dev);
+ ipgre_netlink_parms(data, &nt->parms);
+
+ if (ipgre_tunnel_find(net, &nt->parms, dev->type))
+ return -EEXIST;
+
+ if (dev->type == ARPHRD_ETHER && !tb[IFLA_ADDRESS])
+ eth_hw_addr_random(dev);
+
+ mtu = ipgre_tunnel_bind_dev(dev);
+ if (!tb[IFLA_MTU])
+ dev->mtu = mtu;
+
+ /* Can use a lockless transmit, unless we generate output sequences */
+ if (!(nt->parms.o_flags & GRE_SEQ))
+ dev->features |= NETIF_F_LLTX;
+
+ err = register_netdevice(dev);
+ if (err)
+ goto out;
+
+ dev_hold(dev);
+ ipgre_tunnel_link(ign, nt);
+
+out:
+ return err;
+}
+
+static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
+ struct nlattr *data[])
+{
+ struct ip_tunnel *t, *nt;
+ struct net *net = dev_net(dev);
+ struct ipgre_net *ign = net_generic(net, ipgre_net_id);
+ struct ip_tunnel_parm p;
+ int mtu;
+
+ if (dev == ign->fb_tunnel_dev)
+ return -EINVAL;
+
+ nt = netdev_priv(dev);
+ ipgre_netlink_parms(data, &p);
+
+ t = ipgre_tunnel_locate(net, &p, 0);
+
+ if (t) {
+ if (t->dev != dev)
+ return -EEXIST;
+ } else {
+ t = nt;
+
+ if (dev->type != ARPHRD_ETHER) {
+ unsigned int nflags = 0;
+
+ if (ipv4_is_multicast(p.iph.daddr))
+ nflags = IFF_BROADCAST;
+ else if (p.iph.daddr)
+ nflags = IFF_POINTOPOINT;
+
+ if ((dev->flags ^ nflags) &
+ (IFF_POINTOPOINT | IFF_BROADCAST))
+ return -EINVAL;
+ }
+
+ ipgre_tunnel_unlink(ign, t);
+ t->parms.iph.saddr = p.iph.saddr;
+ t->parms.iph.daddr = p.iph.daddr;
+ t->parms.i_key = p.i_key;
+ if (dev->type != ARPHRD_ETHER) {
+ memcpy(dev->dev_addr, &p.iph.saddr, 4);
+ memcpy(dev->broadcast, &p.iph.daddr, 4);
+ }
+ ipgre_tunnel_link(ign, t);
+ netdev_state_change(dev);
+ }
+
+ t->parms.o_key = p.o_key;
+ 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;
+ mtu = ipgre_tunnel_bind_dev(dev);
+ if (!tb[IFLA_MTU])
+ dev->mtu = mtu;
+ netdev_state_change(dev);
+ }
+
+ return 0;
+}
+
+static size_t ipgre_get_size(const struct net_device *dev)
+{
+ return
+ /* IFLA_GRE_LINK */
+ nla_total_size(4) +
+ /* IFLA_GRE_IFLAGS */
+ nla_total_size(2) +
+ /* IFLA_GRE_OFLAGS */
+ nla_total_size(2) +
+ /* IFLA_GRE_IKEY */
+ nla_total_size(4) +
+ /* IFLA_GRE_OKEY */
+ nla_total_size(4) +
+ /* IFLA_GRE_LOCAL */
+ nla_total_size(4) +
+ /* IFLA_GRE_REMOTE */
+ nla_total_size(4) +
+ /* IFLA_GRE_TTL */
+ nla_total_size(1) +
+ /* IFLA_GRE_TOS */
+ nla_total_size(1) +
+ /* IFLA_GRE_PMTUDISC */
+ nla_total_size(1) +
+ 0;
+}
+
+static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ struct ip_tunnel_parm *p = &t->parms;
+
+ NLA_PUT_U32(skb, IFLA_GRE_LINK, p->link);
+ NLA_PUT_BE16(skb, IFLA_GRE_IFLAGS, p->i_flags);
+ NLA_PUT_BE16(skb, IFLA_GRE_OFLAGS, p->o_flags);
+ NLA_PUT_BE32(skb, IFLA_GRE_IKEY, p->i_key);
+ NLA_PUT_BE32(skb, IFLA_GRE_OKEY, p->o_key);
+ NLA_PUT_BE32(skb, IFLA_GRE_LOCAL, p->iph.saddr);
+ NLA_PUT_BE32(skb, IFLA_GRE_REMOTE, p->iph.daddr);
+ NLA_PUT_U8(skb, IFLA_GRE_TTL, p->iph.ttl);
+ NLA_PUT_U8(skb, IFLA_GRE_TOS, p->iph.tos);
+ NLA_PUT_U8(skb, IFLA_GRE_PMTUDISC, !!(p->iph.frag_off & htons(IP_DF)));
+
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = {
+ [IFLA_GRE_LINK] = { .type = NLA_U32 },
+ [IFLA_GRE_IFLAGS] = { .type = NLA_U16 },
+ [IFLA_GRE_OFLAGS] = { .type = NLA_U16 },
+ [IFLA_GRE_IKEY] = { .type = NLA_U32 },
+ [IFLA_GRE_OKEY] = { .type = NLA_U32 },
+ [IFLA_GRE_LOCAL] = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
+ [IFLA_GRE_REMOTE] = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
+ [IFLA_GRE_TTL] = { .type = NLA_U8 },
+ [IFLA_GRE_TOS] = { .type = NLA_U8 },
+ [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
+};
+
+static struct rtnl_link_ops ipgre_link_ops __read_mostly = {
+ .kind = "gre",
+ .maxtype = IFLA_GRE_MAX,
+ .policy = ipgre_policy,
+ .priv_size = sizeof(struct ip_tunnel),
+ .setup = ipgre_tunnel_setup,
+ .validate = ipgre_tunnel_validate,
+ .newlink = ipgre_newlink,
+ .changelink = ipgre_changelink,
+ .get_size = ipgre_get_size,
+ .fill_info = ipgre_fill_info,
+};
+
+static struct rtnl_link_ops ipgre_tap_ops __read_mostly = {
+ .kind = "gretap",
+ .maxtype = IFLA_GRE_MAX,
+ .policy = ipgre_policy,
+ .priv_size = sizeof(struct ip_tunnel),
+ .setup = ipgre_tap_setup,
+ .validate = ipgre_tap_validate,
+ .newlink = ipgre_newlink,
+ .changelink = ipgre_changelink,
+ .get_size = ipgre_get_size,
+ .fill_info = ipgre_fill_info,
+};
+
+/*
+ * And now the modules code and kernel interface.
+ */
+
+static int __init ipgre_init(void)
+{
+ int err;
+
+ pr_info("GRE over IPv4 tunneling driver\n");
+
+ err = register_pernet_device(&ipgre_net_ops);
+ if (err < 0)
+ return err;
+
+ err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
+ if (err < 0) {
+ pr_info("%s: can't add protocol\n", __func__);
+ goto add_proto_failed;
+ }
+
+ err = rtnl_link_register(&ipgre_link_ops);
+ if (err < 0)
+ goto rtnl_link_failed;
+
+ err = rtnl_link_register(&ipgre_tap_ops);
+ if (err < 0)
+ goto tap_ops_failed;
+
+out:
+ return err;
+
+tap_ops_failed:
+ rtnl_link_unregister(&ipgre_link_ops);
+rtnl_link_failed:
+ gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
+add_proto_failed:
+ unregister_pernet_device(&ipgre_net_ops);
+ goto out;
+}
+
+static void __exit ipgre_fini(void)
+{
+ rtnl_link_unregister(&ipgre_tap_ops);
+ rtnl_link_unregister(&ipgre_link_ops);
+ if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
+ pr_info("%s: can't remove protocol\n", __func__);
+ unregister_pernet_device(&ipgre_net_ops);
+}
+
+module_init(ipgre_init);
+module_exit(ipgre_fini);
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK("gre");
+MODULE_ALIAS_RTNL_LINK("gretap");
+MODULE_ALIAS_NETDEV("gre0");