diff options
Diffstat (limited to 'net/ipv4/ip_gre.c')
| -rw-r--r-- | net/ipv4/ip_gre.c | 1647 |
1 files changed, 1647 insertions, 0 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c new file mode 100644 index 0000000..85c487b --- /dev/null +++ b/net/ipv4/ip_gre.c @@ -0,0 +1,1647 @@ +/* + * 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. + * + */ + +#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/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> + +#ifdef 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 the best + solution, but it supposes maintaing new variable in ALL + skb, even if no tunneling is used. + + Current solution: t->recursion lock breaks dead loops. It looks + like dev->tbusy flag, but I preferred new variable, because + the semantics is different. One day, when hard_start_xmit + will be multithreaded we will have to use skb->encapsulation. + + + + 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, tt 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 + fastly 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 */ + +static int ipgre_fb_tunnel_init(struct net_device *dev); + +#define HASH_SIZE 16 + +static int ipgre_net_id; +struct ipgre_net { + struct ip_tunnel *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] + +static DEFINE_RWLOCK(ipgre_lock); + +/* Given src, dst and key, find appropriate for input tunnel. */ + +static struct ip_tunnel * ipgre_tunnel_lookup(struct net *net, + __be32 remote, __be32 local, + __be32 key, __be16 gre_proto) +{ + unsigned h0 = HASH(remote); + unsigned h1 = HASH(key); + struct ip_tunnel *t; + struct ip_tunnel *t2 = NULL; + struct ipgre_net *ign = net_generic(net, ipgre_net_id); + int dev_type = (gre_proto == htons(ETH_P_TEB)) ? + ARPHRD_ETHER : ARPHRD_IPGRE; + + for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) { + if (local == t->parms.iph.saddr && remote == t->parms.iph.daddr) { + if (t->parms.i_key == key && t->dev->flags & IFF_UP) { + if (t->dev->type == dev_type) + return t; + if (t->dev->type == ARPHRD_IPGRE && !t2) + t2 = t; + } + } + } + + for (t = ign->tunnels_r[h0^h1]; t; t = t->next) { + if (remote == t->parms.iph.daddr) { + if (t->parms.i_key == key && t->dev->flags & IFF_UP) { + if (t->dev->type == dev_type) + return t; + if (t->dev->type == ARPHRD_IPGRE && !t2) + t2 = t; + } + } + } + + for (t = ign->tunnels_l[h1]; t; t = t->next) { + if (local == t->parms.iph.saddr || + (local == t->parms.iph.daddr && + ipv4_is_multicast(local))) { + if (t->parms.i_key == key && t->dev->flags & IFF_UP) { + if (t->dev->type == dev_type) + return t; + if (t->dev->type == ARPHRD_IPGRE && !t2) + t2 = t; + } + } + } + + for (t = ign->tunnels_wc[h1]; t; t = t->next) { + if (t->parms.i_key == key && t->dev->flags & IFF_UP) { + if (t->dev->type == dev_type) + return t; + if (t->dev->type == ARPHRD_IPGRE && !t2) + t2 = t; + } + } + + if (t2) + return t2; + + if (ign->fb_tunnel_dev->flags&IFF_UP) + return netdev_priv(ign->fb_tunnel_dev); + return NULL; +} + +static struct ip_tunnel **__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 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 **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 **tp = ipgre_bucket(ign, t); + + t->next = *tp; + write_lock_bh(&ipgre_lock); + *tp = t; + write_unlock_bh(&ipgre_lock); +} + +static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t) +{ + struct ip_tunnel **tp; + + for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) { + if (t == *tp) { + write_lock_bh(&ipgre_lock); + *tp = t->next; + write_unlock_bh(&ipgre_lock); + 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; + struct ip_tunnel *t, **tp; + struct ipgre_net *ign = net_generic(net, ipgre_net_id); + + for (tp = __ipgre_bucket(ign, parms); (t = *tp) != NULL; tp = &t->next) + if (local == t->parms.iph.saddr && + remote == t->parms.iph.daddr && + key == t->parms.i_key && + 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 + sprintf(name, "gre%%d"); + + dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup); + if (!dev) + return NULL; + + dev_net_set(dev, net); + + if (strchr(name, '%')) { + if (dev_alloc_name(dev, name) < 0) + goto failed_free; + } + + 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; + + 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 standrads established + by themself??? + */ + + struct iphdr *iph = (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; + } + + read_lock(&ipgre_lock); + t = ipgre_tunnel_lookup(dev_net(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 (jiffies - t->err_time < IPTUNNEL_ERR_TIMEO) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; +out: + read_unlock(&ipgre_lock); + return; +} + +static inline void ipgre_ecn_decapsulate(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, 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((struct ipv6hdr *)old_iph); + return INET_ECN_encapsulate(tos, inner); +} + +static int ipgre_rcv(struct sk_buff *skb) +{ + 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; + unsigned int len; + + 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); + + read_lock(&ipgre_lock); + if ((tunnel = ipgre_tunnel_lookup(dev_net(skb->dev), + iph->saddr, iph->daddr, key, + gre_proto))) { + struct net_device_stats *stats = &tunnel->dev->stats; + + 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 (skb->rtable->fl.iif == 0) + goto drop; + stats->multicast++; + skb->pkt_type = PACKET_BROADCAST; + } +#endif + + if (((flags&GRE_CSUM) && csum) || + (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) { + stats->rx_crc_errors++; + 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)) { + stats->rx_fifo_errors++; + stats->rx_errors++; + goto drop; + } + tunnel->i_seqno = seqno + 1; + } + + len = skb->len; + + /* Warning: All skb pointers will be invalidated! */ + if (tunnel->dev->type == ARPHRD_ETHER) { + if (!pskb_may_pull(skb, ETH_HLEN)) { + stats->rx_length_errors++; + 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); + } + + stats->rx_packets++; + stats->rx_bytes += len; + skb->dev = tunnel->dev; + dst_release(skb->dst); + skb->dst = NULL; + nf_reset(skb); + + skb_reset_network_header(skb); + ipgre_ecn_decapsulate(iph, skb); + + netif_rx(skb); + read_unlock(&ipgre_lock); + return(0); + } + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); + +drop: + read_unlock(&ipgre_lock); +drop_nolock: + kfree_skb(skb); + return(0); +} + +static int ipgre_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 *old_iph = ip_hdr(skb); + struct iphdr *tiph; + 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 (tunnel->recursion++) { + stats->collisions++; + goto tx_error; + } + + if (dev->type == ARPHRD_ETHER) + IPCB(skb)->flags = 0; + + if (dev->header_ops && dev->type == ARPHRD_IPGRE) { + gre_hlen = 0; + tiph = (struct iphdr*)skb->data; + } else { + gre_hlen = tunnel->hlen; + tiph = &tunnel->parms.iph; + } + + if ((dst = tiph->daddr) == 0) { + /* NBMA tunnel */ + + if (skb->dst == NULL) { + stats->tx_fifo_errors++; + goto tx_error; + } + + if (skb->protocol == htons(ETH_P_IP)) { + rt = skb->rtable; + if ((dst = rt->rt_gateway) == 0) + goto tx_error_icmp; + } +#ifdef CONFIG_IPV6 + else if (skb->protocol == htons(ETH_P_IPV6)) { + struct in6_addr *addr6; + int addr_type; + struct neighbour *neigh = skb->dst->neighbour; + + if (neigh == NULL) + goto tx_error; + + addr6 = (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) + goto tx_error_icmp; + + dst = addr6->s6_addr32[3]; + } +#endif + else + goto tx_error; + } + + tos = tiph->tos; + if (tos&1) { + if (skb->protocol == htons(ETH_P_IP)) + tos = old_iph->tos; + tos &= ~1; + } + + { + struct flowi fl = { .oif = tunnel->parms.link, + .nl_u = { .ip4_u = + { .daddr = dst, + .saddr = tiph->saddr, + .tos = RT_TOS(tos) } }, + .proto = IPPROTO_GRE }; + if (ip_route_output_key(dev_net(dev), &rt, &fl)) { + stats->tx_carrier_errors++; + goto tx_error; + } + } + tdev = rt->u.dst.dev; + + if (tdev == dev) { + ip_rt_put(rt); + stats->collisions++; + goto tx_error; + } + + df = tiph->frag_off; + if (df) + mtu = dst_mtu(&rt->u.dst) - dev->hard_header_len - tunnel->hlen; + else + mtu = skb->dst ? dst_mtu(skb->dst) : dev->mtu; + + if (skb->dst) + skb->dst->ops->update_pmtu(skb->dst, 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; + } + } +#ifdef CONFIG_IPV6 + else if (skb->protocol == htons(ETH_P_IPV6)) { + struct rt6_info *rt6 = (struct rt6_info*)skb->dst; + + if (rt6 && mtu < dst_mtu(skb->dst) && 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; + skb->dst->metrics[RTAX_MTU-1] = mtu; + } + } + + if (mtu >= IPV6_MIN_MTU && mtu < skb->len - tunnel->hlen + gre_hlen) { + icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu, dev); + ip_rt_put(rt); + goto tx_error; + } + } +#endif + + 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; + } + + max_headroom = LL_RESERVED_SPACE(tdev) + gre_hlen; + + 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_reset_transport_header(skb); + skb_push(skb, gre_hlen); + 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_GRE; + iph->tos = ipgre_ecn_encapsulate(tos, old_iph, skb); + iph->daddr = rt->rt_dst; + iph->saddr = rt->rt_src; + + if ((iph->ttl = tiph->ttl) == 0) { + if (skb->protocol == htons(ETH_P_IP)) + iph->ttl = old_iph->ttl; +#ifdef CONFIG_IPV6 + else if (skb->protocol == htons(ETH_P_IPV6)) + iph->ttl = ((struct ipv6hdr*)old_iph)->hop_limit; +#endif + else + iph->ttl = dst_metric(&rt->u.dst, RTAX_HOPLIMIT); + } + + ((__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); + + 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 int ipgre_tunnel_bind_dev(struct net_device *dev) +{ + struct net_device *tdev = NULL; + struct ip_tunnel *tunnel; + 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 flowi fl = { .oif = tunnel->parms.link, + .nl_u = { .ip4_u = + { .daddr = iph->daddr, + .saddr = iph->saddr, + .tos = RT_TOS(iph->tos) } }, + .proto = IPPROTO_GRE }; + struct rtable *rt; + if (!ip_route_output_key(dev_net(dev), &rt, &fl)) { + tdev = rt->u.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 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); + 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 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); + return t->hlen; + } + if (iph->daddr && !ipv4_is_multicast(iph->daddr)) + return t->hlen; + + return -t->hlen; +} + +static int ipgre_header_parse(const struct sk_buff *skb, unsigned char *haddr) +{ + struct iphdr *iph = (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 flowi fl = { .oif = t->parms.link, + .nl_u = { .ip4_u = + { .daddr = t->parms.iph.daddr, + .saddr = t->parms.iph.saddr, + .tos = RT_TOS(t->parms.iph.tos) } }, + .proto = IPPROTO_GRE }; + struct rtable *rt; + if (ip_route_output_key(dev_net(dev), &rt, &fl)) + return -EADDRNOTAVAIL; + dev = rt->u.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); + in_dev_put(in_dev); + } + } + return 0; +} + +#endif + +static void ipgre_tunnel_setup(struct net_device *dev) +{ + dev->init = ipgre_tunnel_init; + dev->uninit = ipgre_tunnel_uninit; + dev->destructor = free_netdev; + dev->hard_start_xmit = ipgre_tunnel_xmit; + dev->do_ioctl = ipgre_tunnel_ioctl; + dev->change_mtu = ipgre_tunnel_change_mtu; + + 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; +} + +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; + dev->open = ipgre_open; + dev->stop = ipgre_close; + } +#endif + } else + dev->header_ops = &ipgre_header_ops; + + return 0; +} + +static int ipgre_fb_tunnel_init(struct net_device *dev) +{ + struct ip_tunnel *tunnel = netdev_priv(dev); + struct iphdr *iph = &tunnel->parms.iph; + struct ipgre_net *ign = net_generic(dev_net(dev), ipgre_net_id); + + 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); + ign->tunnels_wc[0] = tunnel; + return 0; +} + + +static struct net_protocol ipgre_protocol = { + .handler = ipgre_rcv, + .err_handler = ipgre_err, + .netns_ok = 1, +}; + +static void ipgre_destroy_tunnels(struct ipgre_net *ign) +{ + int prio; + + for (prio = 0; prio < 4; prio++) { + int h; + for (h = 0; h < HASH_SIZE; h++) { + struct ip_tunnel *t; + while ((t = ign->tunnels[prio][h]) != NULL) + unregister_netdevice(t->dev); + } + } +} + +static int ipgre_init_net(struct net *net) +{ + int err; + struct ipgre_net *ign; + + err = -ENOMEM; + ign = kzalloc(sizeof(struct ipgre_net), GFP_KERNEL); + if (ign == NULL) + goto err_alloc; + + err = net_assign_generic(net, ipgre_net_id, ign); + if (err < 0) + goto err_assign; + + 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; + } + + ign->fb_tunnel_dev->init = ipgre_fb_tunnel_init; + dev_net_set(ign->fb_tunnel_dev, net); + ign->fb_tunnel_dev->rtnl_link_ops = &ipgre_link_ops; + + if ((err = register_netdev(ign->fb_tunnel_dev))) + goto err_reg_dev; + + return 0; + +err_reg_dev: + free_netdev(ign->fb_tunnel_dev); +err_alloc_dev: + /* nothing */ +err_assign: + kfree(ign); +err_alloc: + return err; +} + +static void ipgre_exit_net(struct net *net) +{ + struct ipgre_net *ign; + + ign = net_generic(net, ipgre_net_id); + rtnl_lock(); + ipgre_destroy_tunnels(ign); + rtnl_unlock(); + kfree(ign); +} + +static struct pernet_operations ipgre_net_ops = { + .init = ipgre_init_net, + .exit = ipgre_exit_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); + + return 0; +} + +static void ipgre_tap_setup(struct net_device *dev) +{ + + ether_setup(dev); + + dev->init = ipgre_tap_init; + dev->uninit = ipgre_tunnel_uninit; + dev->destructor = free_netdev; + dev->hard_start_xmit = ipgre_tunnel_xmit; + dev->change_mtu = ipgre_tunnel_change_mtu; + + dev->iflink = 0; + dev->features |= NETIF_F_NETNS_LOCAL; +} + +static int ipgre_newlink(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]) + random_ether_addr(dev->dev_addr); + + mtu = ipgre_tunnel_bind_dev(dev); + if (!tb[IFLA_MTU]) + dev->mtu = mtu; + + 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 { + unsigned nflags = 0; + + t = nt; + + 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; + 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; + + printk(KERN_INFO "GRE over IPv4 tunneling driver\n"); + + if (inet_add_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) { + printk(KERN_INFO "ipgre init: can't add protocol\n"); + return -EAGAIN; + } + + err = register_pernet_gen_device(&ipgre_net_id, &ipgre_net_ops); + if (err < 0) + goto gen_device_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: + unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops); +gen_device_failed: + inet_del_protocol(&ipgre_protocol, IPPROTO_GRE); + goto out; +} + +static void __exit ipgre_fini(void) +{ + rtnl_link_unregister(&ipgre_tap_ops); + rtnl_link_unregister(&ipgre_link_ops); + unregister_pernet_gen_device(ipgre_net_id, &ipgre_net_ops); + if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0) + printk(KERN_INFO "ipgre close: can't remove protocol\n"); +} + +module_init(ipgre_init); +module_exit(ipgre_fini); +MODULE_LICENSE("GPL"); +MODULE_ALIAS_RTNL_LINK("gre"); +MODULE_ALIAS_RTNL_LINK("gretap"); 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