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-rw-r--r--net/ipv4/ip_gre.c1801
1 files changed, 1801 insertions, 0 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
new file mode 100644
index 000000000..a6ad0fe13
--- /dev/null
+++ b/net/ipv4/ip_gre.c
@@ -0,0 +1,1801 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Linux NET3: GRE over IP protocol decoder.
+ *
+ * Authors: Alexey Kuznetsov (kuznet@ms2.inr.ac.ru)
+ */
+
+#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 <linux/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/if_vlan.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/ip_tunnels.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>
+#include <net/dst_metadata.h>
+#include <net/erspan.h>
+
+/*
+ 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. :-)
+
+ Alexey Kuznetsov.
+ */
+
+static bool log_ecn_error = true;
+module_param(log_ecn_error, bool, 0644);
+MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
+
+static struct rtnl_link_ops ipgre_link_ops __read_mostly;
+static int ipgre_tunnel_init(struct net_device *dev);
+static void erspan_build_header(struct sk_buff *skb,
+ u32 id, u32 index,
+ bool truncate, bool is_ipv4);
+
+static unsigned int ipgre_net_id __read_mostly;
+static unsigned int gre_tap_net_id __read_mostly;
+static unsigned int erspan_net_id __read_mostly;
+
+static int ipgre_err(struct sk_buff *skb, u32 info,
+ const struct tnl_ptk_info *tpi)
+{
+
+ /* 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???
+ */
+ struct net *net = dev_net(skb->dev);
+ struct ip_tunnel_net *itn;
+ const struct iphdr *iph;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ unsigned int data_len = 0;
+ struct ip_tunnel *t;
+
+ if (tpi->proto == htons(ETH_P_TEB))
+ itn = net_generic(net, gre_tap_net_id);
+ else if (tpi->proto == htons(ETH_P_ERSPAN) ||
+ tpi->proto == htons(ETH_P_ERSPAN2))
+ itn = net_generic(net, erspan_net_id);
+ else
+ itn = net_generic(net, ipgre_net_id);
+
+ iph = (const struct iphdr *)(icmp_hdr(skb) + 1);
+ t = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+ iph->daddr, iph->saddr, tpi->key);
+
+ if (!t)
+ return -ENOENT;
+
+ 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;
+ 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;
+ data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */
+ break;
+
+ case ICMP_REDIRECT:
+ break;
+ }
+
+#if IS_ENABLED(CONFIG_IPV6)
+ if (tpi->proto == htons(ETH_P_IPV6) &&
+ !ip6_err_gen_icmpv6_unreach(skb, iph->ihl * 4 + tpi->hdr_len,
+ type, data_len))
+ return 0;
+#endif
+
+ if (t->parms.iph.daddr == 0 ||
+ ipv4_is_multicast(t->parms.iph.daddr))
+ return 0;
+
+ if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
+ return 0;
+
+ if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
+ t->err_count++;
+ else
+ t->err_count = 1;
+ t->err_time = jiffies;
+
+ return 0;
+}
+
+static void gre_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 = (struct iphdr *)skb->data;
+ const int type = icmp_hdr(skb)->type;
+ const int code = icmp_hdr(skb)->code;
+ struct tnl_ptk_info tpi;
+
+ if (gre_parse_header(skb, &tpi, NULL, htons(ETH_P_IP),
+ iph->ihl * 4) < 0)
+ return;
+
+ if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
+ ipv4_update_pmtu(skb, dev_net(skb->dev), info,
+ skb->dev->ifindex, IPPROTO_GRE);
+ return;
+ }
+ if (type == ICMP_REDIRECT) {
+ ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex,
+ IPPROTO_GRE);
+ return;
+ }
+
+ ipgre_err(skb, info, &tpi);
+}
+
+static bool is_erspan_type1(int gre_hdr_len)
+{
+ /* Both ERSPAN type I (version 0) and type II (version 1) use
+ * protocol 0x88BE, but the type I has only 4-byte GRE header,
+ * while type II has 8-byte.
+ */
+ return gre_hdr_len == 4;
+}
+
+static int erspan_rcv(struct sk_buff *skb, struct tnl_ptk_info *tpi,
+ int gre_hdr_len)
+{
+ struct net *net = dev_net(skb->dev);
+ struct metadata_dst *tun_dst = NULL;
+ struct erspan_base_hdr *ershdr;
+ struct ip_tunnel_net *itn;
+ struct ip_tunnel *tunnel;
+ const struct iphdr *iph;
+ struct erspan_md2 *md2;
+ int ver;
+ int len;
+
+ itn = net_generic(net, erspan_net_id);
+ iph = ip_hdr(skb);
+ if (is_erspan_type1(gre_hdr_len)) {
+ ver = 0;
+ tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
+ tpi->flags | TUNNEL_NO_KEY,
+ iph->saddr, iph->daddr, 0);
+ } else {
+ ershdr = (struct erspan_base_hdr *)(skb->data + gre_hdr_len);
+ ver = ershdr->ver;
+ tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
+ tpi->flags | TUNNEL_KEY,
+ iph->saddr, iph->daddr, tpi->key);
+ }
+
+ if (tunnel) {
+ if (is_erspan_type1(gre_hdr_len))
+ len = gre_hdr_len;
+ else
+ len = gre_hdr_len + erspan_hdr_len(ver);
+
+ if (unlikely(!pskb_may_pull(skb, len)))
+ return PACKET_REJECT;
+
+ if (__iptunnel_pull_header(skb,
+ len,
+ htons(ETH_P_TEB),
+ false, false) < 0)
+ goto drop;
+
+ if (tunnel->collect_md) {
+ struct erspan_metadata *pkt_md, *md;
+ struct ip_tunnel_info *info;
+ unsigned char *gh;
+ __be64 tun_id;
+ __be16 flags;
+
+ tpi->flags |= TUNNEL_KEY;
+ flags = tpi->flags;
+ tun_id = key32_to_tunnel_id(tpi->key);
+
+ tun_dst = ip_tun_rx_dst(skb, flags,
+ tun_id, sizeof(*md));
+ if (!tun_dst)
+ return PACKET_REJECT;
+
+ /* skb can be uncloned in __iptunnel_pull_header, so
+ * old pkt_md is no longer valid and we need to reset
+ * it
+ */
+ gh = skb_network_header(skb) +
+ skb_network_header_len(skb);
+ pkt_md = (struct erspan_metadata *)(gh + gre_hdr_len +
+ sizeof(*ershdr));
+ md = ip_tunnel_info_opts(&tun_dst->u.tun_info);
+ md->version = ver;
+ md2 = &md->u.md2;
+ memcpy(md2, pkt_md, ver == 1 ? ERSPAN_V1_MDSIZE :
+ ERSPAN_V2_MDSIZE);
+
+ info = &tun_dst->u.tun_info;
+ info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
+ info->options_len = sizeof(*md);
+ }
+
+ skb_reset_mac_header(skb);
+ ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
+ return PACKET_RCVD;
+ }
+ return PACKET_REJECT;
+
+drop:
+ kfree_skb(skb);
+ return PACKET_RCVD;
+}
+
+static int __ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
+ struct ip_tunnel_net *itn, int hdr_len, bool raw_proto)
+{
+ struct metadata_dst *tun_dst = NULL;
+ const struct iphdr *iph;
+ struct ip_tunnel *tunnel;
+
+ iph = ip_hdr(skb);
+ tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, tpi->flags,
+ iph->saddr, iph->daddr, tpi->key);
+
+ if (tunnel) {
+ const struct iphdr *tnl_params;
+
+ if (__iptunnel_pull_header(skb, hdr_len, tpi->proto,
+ raw_proto, false) < 0)
+ goto drop;
+
+ if (tunnel->dev->type != ARPHRD_NONE)
+ skb_pop_mac_header(skb);
+ else
+ skb_reset_mac_header(skb);
+
+ tnl_params = &tunnel->parms.iph;
+ if (tunnel->collect_md || tnl_params->daddr == 0) {
+ __be16 flags;
+ __be64 tun_id;
+
+ flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY);
+ tun_id = key32_to_tunnel_id(tpi->key);
+ tun_dst = ip_tun_rx_dst(skb, flags, tun_id, 0);
+ if (!tun_dst)
+ return PACKET_REJECT;
+ }
+
+ ip_tunnel_rcv(tunnel, skb, tpi, tun_dst, log_ecn_error);
+ return PACKET_RCVD;
+ }
+ return PACKET_NEXT;
+
+drop:
+ kfree_skb(skb);
+ return PACKET_RCVD;
+}
+
+static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi,
+ int hdr_len)
+{
+ struct net *net = dev_net(skb->dev);
+ struct ip_tunnel_net *itn;
+ int res;
+
+ if (tpi->proto == htons(ETH_P_TEB))
+ itn = net_generic(net, gre_tap_net_id);
+ else
+ itn = net_generic(net, ipgre_net_id);
+
+ res = __ipgre_rcv(skb, tpi, itn, hdr_len, false);
+ if (res == PACKET_NEXT && tpi->proto == htons(ETH_P_TEB)) {
+ /* ipgre tunnels in collect metadata mode should receive
+ * also ETH_P_TEB traffic.
+ */
+ itn = net_generic(net, ipgre_net_id);
+ res = __ipgre_rcv(skb, tpi, itn, hdr_len, true);
+ }
+ return res;
+}
+
+static int gre_rcv(struct sk_buff *skb)
+{
+ struct tnl_ptk_info tpi;
+ bool csum_err = false;
+ int hdr_len;
+
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
+ /* Looped back packet, drop it! */
+ if (rt_is_output_route(skb_rtable(skb)))
+ goto drop;
+ }
+#endif
+
+ hdr_len = gre_parse_header(skb, &tpi, &csum_err, htons(ETH_P_IP), 0);
+ if (hdr_len < 0)
+ goto drop;
+
+ if (unlikely(tpi.proto == htons(ETH_P_ERSPAN) ||
+ tpi.proto == htons(ETH_P_ERSPAN2))) {
+ if (erspan_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
+ return 0;
+ goto out;
+ }
+
+ if (ipgre_rcv(skb, &tpi, hdr_len) == PACKET_RCVD)
+ return 0;
+
+out:
+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+drop:
+ kfree_skb(skb);
+ return 0;
+}
+
+static void __gre_xmit(struct sk_buff *skb, struct net_device *dev,
+ const struct iphdr *tnl_params,
+ __be16 proto)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ __be16 flags = tunnel->parms.o_flags;
+
+ /* Push GRE header. */
+ gre_build_header(skb, tunnel->tun_hlen,
+ flags, proto, tunnel->parms.o_key,
+ (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
+
+ ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol);
+}
+
+static int gre_handle_offloads(struct sk_buff *skb, bool csum)
+{
+ return iptunnel_handle_offloads(skb, csum ? SKB_GSO_GRE_CSUM : SKB_GSO_GRE);
+}
+
+static void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev,
+ __be16 proto)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct ip_tunnel_info *tun_info;
+ const struct ip_tunnel_key *key;
+ int tunnel_hlen;
+ __be16 flags;
+
+ tun_info = skb_tunnel_info(skb);
+ if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
+ ip_tunnel_info_af(tun_info) != AF_INET))
+ goto err_free_skb;
+
+ key = &tun_info->key;
+ tunnel_hlen = gre_calc_hlen(key->tun_flags);
+
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto err_free_skb;
+
+ /* Push Tunnel header. */
+ if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)))
+ goto err_free_skb;
+
+ flags = tun_info->key.tun_flags &
+ (TUNNEL_CSUM | TUNNEL_KEY | TUNNEL_SEQ);
+ gre_build_header(skb, tunnel_hlen, flags, proto,
+ tunnel_id_to_key32(tun_info->key.tun_id),
+ (flags & TUNNEL_SEQ) ? htonl(atomic_fetch_inc(&tunnel->o_seqno)) : 0);
+
+ ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
+
+ return;
+
+err_free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+}
+
+static void erspan_fb_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct ip_tunnel_info *tun_info;
+ const struct ip_tunnel_key *key;
+ struct erspan_metadata *md;
+ bool truncate = false;
+ __be16 proto;
+ int tunnel_hlen;
+ int version;
+ int nhoff;
+
+ tun_info = skb_tunnel_info(skb);
+ if (unlikely(!tun_info || !(tun_info->mode & IP_TUNNEL_INFO_TX) ||
+ ip_tunnel_info_af(tun_info) != AF_INET))
+ goto err_free_skb;
+
+ key = &tun_info->key;
+ if (!(tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT))
+ goto err_free_skb;
+ if (tun_info->options_len < sizeof(*md))
+ goto err_free_skb;
+ md = ip_tunnel_info_opts(tun_info);
+
+ /* ERSPAN has fixed 8 byte GRE header */
+ version = md->version;
+ tunnel_hlen = 8 + erspan_hdr_len(version);
+
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto err_free_skb;
+
+ if (gre_handle_offloads(skb, false))
+ goto err_free_skb;
+
+ if (skb->len > dev->mtu + dev->hard_header_len) {
+ pskb_trim(skb, dev->mtu + dev->hard_header_len);
+ truncate = true;
+ }
+
+ nhoff = skb_network_offset(skb);
+ if (skb->protocol == htons(ETH_P_IP) &&
+ (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff))
+ truncate = true;
+
+ if (skb->protocol == htons(ETH_P_IPV6)) {
+ int thoff;
+
+ if (skb_transport_header_was_set(skb))
+ thoff = skb_transport_offset(skb);
+ else
+ thoff = nhoff + sizeof(struct ipv6hdr);
+ if (ntohs(ipv6_hdr(skb)->payload_len) > skb->len - thoff)
+ truncate = true;
+ }
+
+ if (version == 1) {
+ erspan_build_header(skb, ntohl(tunnel_id_to_key32(key->tun_id)),
+ ntohl(md->u.index), truncate, true);
+ proto = htons(ETH_P_ERSPAN);
+ } else if (version == 2) {
+ erspan_build_header_v2(skb,
+ ntohl(tunnel_id_to_key32(key->tun_id)),
+ md->u.md2.dir,
+ get_hwid(&md->u.md2),
+ truncate, true);
+ proto = htons(ETH_P_ERSPAN2);
+ } else {
+ goto err_free_skb;
+ }
+
+ gre_build_header(skb, 8, TUNNEL_SEQ,
+ proto, 0, htonl(atomic_fetch_inc(&tunnel->o_seqno)));
+
+ ip_md_tunnel_xmit(skb, dev, IPPROTO_GRE, tunnel_hlen);
+
+ return;
+
+err_free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+}
+
+static int gre_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
+{
+ struct ip_tunnel_info *info = skb_tunnel_info(skb);
+ const struct ip_tunnel_key *key;
+ struct rtable *rt;
+ struct flowi4 fl4;
+
+ if (ip_tunnel_info_af(info) != AF_INET)
+ return -EINVAL;
+
+ key = &info->key;
+ ip_tunnel_init_flow(&fl4, IPPROTO_GRE, key->u.ipv4.dst, key->u.ipv4.src,
+ tunnel_id_to_key32(key->tun_id),
+ key->tos & ~INET_ECN_MASK, 0, skb->mark,
+ skb_get_hash(skb));
+ rt = ip_route_output_key(dev_net(dev), &fl4);
+ if (IS_ERR(rt))
+ return PTR_ERR(rt);
+
+ ip_rt_put(rt);
+ info->key.u.ipv4.src = fl4.saddr;
+ return 0;
+}
+
+static netdev_tx_t ipgre_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ const struct iphdr *tnl_params;
+
+ if (!pskb_inet_may_pull(skb))
+ goto free_skb;
+
+ if (tunnel->collect_md) {
+ gre_fb_xmit(skb, dev, skb->protocol);
+ return NETDEV_TX_OK;
+ }
+
+ if (dev->header_ops) {
+ int pull_len = tunnel->hlen + sizeof(struct iphdr);
+
+ if (skb_cow_head(skb, 0))
+ goto free_skb;
+
+ tnl_params = (const struct iphdr *)skb->data;
+
+ if (!pskb_network_may_pull(skb, pull_len))
+ goto free_skb;
+
+ /* ip_tunnel_xmit() needs skb->data pointing to gre header. */
+ skb_pull(skb, pull_len);
+ skb_reset_mac_header(skb);
+
+ if (skb->ip_summed == CHECKSUM_PARTIAL &&
+ skb_checksum_start(skb) < skb->data)
+ goto free_skb;
+ } else {
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto free_skb;
+
+ tnl_params = &tunnel->parms.iph;
+ }
+
+ if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
+ goto free_skb;
+
+ __gre_xmit(skb, dev, tnl_params, skb->protocol);
+ return NETDEV_TX_OK;
+
+free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return NETDEV_TX_OK;
+}
+
+static netdev_tx_t erspan_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ bool truncate = false;
+ __be16 proto;
+
+ if (!pskb_inet_may_pull(skb))
+ goto free_skb;
+
+ if (tunnel->collect_md) {
+ erspan_fb_xmit(skb, dev);
+ return NETDEV_TX_OK;
+ }
+
+ if (gre_handle_offloads(skb, false))
+ goto free_skb;
+
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto free_skb;
+
+ if (skb->len > dev->mtu + dev->hard_header_len) {
+ pskb_trim(skb, dev->mtu + dev->hard_header_len);
+ truncate = true;
+ }
+
+ /* Push ERSPAN header */
+ if (tunnel->erspan_ver == 0) {
+ proto = htons(ETH_P_ERSPAN);
+ tunnel->parms.o_flags &= ~TUNNEL_SEQ;
+ } else if (tunnel->erspan_ver == 1) {
+ erspan_build_header(skb, ntohl(tunnel->parms.o_key),
+ tunnel->index,
+ truncate, true);
+ proto = htons(ETH_P_ERSPAN);
+ } else if (tunnel->erspan_ver == 2) {
+ erspan_build_header_v2(skb, ntohl(tunnel->parms.o_key),
+ tunnel->dir, tunnel->hwid,
+ truncate, true);
+ proto = htons(ETH_P_ERSPAN2);
+ } else {
+ goto free_skb;
+ }
+
+ tunnel->parms.o_flags &= ~TUNNEL_KEY;
+ __gre_xmit(skb, dev, &tunnel->parms.iph, proto);
+ return NETDEV_TX_OK;
+
+free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return NETDEV_TX_OK;
+}
+
+static netdev_tx_t gre_tap_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+
+ if (!pskb_inet_may_pull(skb))
+ goto free_skb;
+
+ if (tunnel->collect_md) {
+ gre_fb_xmit(skb, dev, htons(ETH_P_TEB));
+ return NETDEV_TX_OK;
+ }
+
+ if (gre_handle_offloads(skb, !!(tunnel->parms.o_flags & TUNNEL_CSUM)))
+ goto free_skb;
+
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto free_skb;
+
+ __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB));
+ return NETDEV_TX_OK;
+
+free_skb:
+ kfree_skb(skb);
+ dev->stats.tx_dropped++;
+ return NETDEV_TX_OK;
+}
+
+static void ipgre_link_update(struct net_device *dev, bool set_mtu)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ int len;
+
+ len = tunnel->tun_hlen;
+ tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+ len = tunnel->tun_hlen - len;
+ tunnel->hlen = tunnel->hlen + len;
+
+ if (dev->header_ops)
+ dev->hard_header_len += len;
+ else
+ dev->needed_headroom += len;
+
+ if (set_mtu)
+ dev->mtu = max_t(int, dev->mtu - len, 68);
+
+ if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
+ if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
+ tunnel->encap.type == TUNNEL_ENCAP_NONE) {
+ dev->features |= NETIF_F_GSO_SOFTWARE;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+ } else {
+ dev->features &= ~NETIF_F_GSO_SOFTWARE;
+ dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+ }
+ dev->features |= NETIF_F_LLTX;
+ } else {
+ dev->hw_features &= ~NETIF_F_GSO_SOFTWARE;
+ dev->features &= ~(NETIF_F_LLTX | NETIF_F_GSO_SOFTWARE);
+ }
+}
+
+static int ipgre_tunnel_ctl(struct net_device *dev, struct ip_tunnel_parm *p,
+ int cmd)
+{
+ int err;
+
+ if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
+ 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)))
+ return -EINVAL;
+ }
+
+ p->i_flags = gre_flags_to_tnl_flags(p->i_flags);
+ p->o_flags = gre_flags_to_tnl_flags(p->o_flags);
+
+ err = ip_tunnel_ctl(dev, p, cmd);
+ if (err)
+ return err;
+
+ if (cmd == SIOCCHGTUNNEL) {
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ t->parms.i_flags = p->i_flags;
+ t->parms.o_flags = p->o_flags;
+
+ if (strcmp(dev->rtnl_link_ops->kind, "erspan"))
+ ipgre_link_update(dev, true);
+ }
+
+ p->i_flags = gre_tnl_flags_to_gre_flags(p->i_flags);
+ p->o_flags = gre_tnl_flags_to_gre_flags(p->o_flags);
+ 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 gre_base_hdr *greh;
+
+ iph = skb_push(skb, t->hlen + sizeof(*iph));
+ greh = (struct gre_base_hdr *)(iph+1);
+ greh->flags = gre_tnl_flags_to_gre_flags(t->parms.o_flags);
+ greh->protocol = htons(type);
+
+ memcpy(iph, &t->parms.iph, sizeof(struct iphdr));
+
+ /* 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 + sizeof(*iph);
+
+ return -(t->hlen + sizeof(*iph));
+}
+
+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(t->net, &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))
+ 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(t->net, 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 = ip_tunnel_uninit,
+#ifdef CONFIG_NET_IPGRE_BROADCAST
+ .ndo_open = ipgre_open,
+ .ndo_stop = ipgre_close,
+#endif
+ .ndo_start_xmit = ipgre_xmit,
+ .ndo_do_ioctl = ip_tunnel_ioctl,
+ .ndo_change_mtu = ip_tunnel_change_mtu,
+ .ndo_get_stats64 = ip_tunnel_get_stats64,
+ .ndo_get_iflink = ip_tunnel_get_iflink,
+ .ndo_tunnel_ctl = ipgre_tunnel_ctl,
+};
+
+#define GRE_FEATURES (NETIF_F_SG | \
+ NETIF_F_FRAGLIST | \
+ NETIF_F_HIGHDMA | \
+ NETIF_F_HW_CSUM)
+
+static void ipgre_tunnel_setup(struct net_device *dev)
+{
+ dev->netdev_ops = &ipgre_netdev_ops;
+ dev->type = ARPHRD_IPGRE;
+ ip_tunnel_setup(dev, ipgre_net_id);
+}
+
+static void __gre_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel;
+
+ tunnel = netdev_priv(dev);
+ tunnel->tun_hlen = gre_calc_hlen(tunnel->parms.o_flags);
+ tunnel->parms.iph.protocol = IPPROTO_GRE;
+
+ tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen;
+ dev->needed_headroom = tunnel->hlen + sizeof(tunnel->parms.iph);
+
+ dev->features |= GRE_FEATURES;
+ dev->hw_features |= GRE_FEATURES;
+
+ if (!(tunnel->parms.o_flags & TUNNEL_SEQ)) {
+ /* TCP offload with GRE SEQ is not supported, nor
+ * can we support 2 levels of outer headers requiring
+ * an update.
+ */
+ if (!(tunnel->parms.o_flags & TUNNEL_CSUM) ||
+ (tunnel->encap.type == TUNNEL_ENCAP_NONE)) {
+ dev->features |= NETIF_F_GSO_SOFTWARE;
+ dev->hw_features |= NETIF_F_GSO_SOFTWARE;
+ }
+
+ /* Can use a lockless transmit, unless we generate
+ * output sequences
+ */
+ dev->features |= NETIF_F_LLTX;
+ }
+}
+
+static int ipgre_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+ struct iphdr *iph = &tunnel->parms.iph;
+
+ __gre_tunnel_init(dev);
+
+ memcpy(dev->dev_addr, &iph->saddr, 4);
+ memcpy(dev->broadcast, &iph->daddr, 4);
+
+ dev->flags = IFF_NOARP;
+ netif_keep_dst(dev);
+ dev->addr_len = 4;
+
+ if (iph->daddr && !tunnel->collect_md) {
+#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->hard_header_len = tunnel->hlen + sizeof(*iph);
+ dev->needed_headroom = 0;
+ }
+#endif
+ } else if (!tunnel->collect_md) {
+ dev->header_ops = &ipgre_header_ops;
+ dev->hard_header_len = tunnel->hlen + sizeof(*iph);
+ dev->needed_headroom = 0;
+ }
+
+ return ip_tunnel_init(dev);
+}
+
+static const struct gre_protocol ipgre_protocol = {
+ .handler = gre_rcv,
+ .err_handler = gre_err,
+};
+
+static int __net_init ipgre_init_net(struct net *net)
+{
+ return ip_tunnel_init_net(net, ipgre_net_id, &ipgre_link_ops, NULL);
+}
+
+static void __net_exit ipgre_exit_batch_net(struct list_head *list_net)
+{
+ ip_tunnel_delete_nets(list_net, ipgre_net_id, &ipgre_link_ops);
+}
+
+static struct pernet_operations ipgre_net_ops = {
+ .init = ipgre_init_net,
+ .exit_batch = ipgre_exit_batch_net,
+ .id = &ipgre_net_id,
+ .size = sizeof(struct ip_tunnel_net),
+};
+
+static int ipgre_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ __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;
+
+ if (data[IFLA_GRE_COLLECT_METADATA] &&
+ data[IFLA_GRE_ENCAP_TYPE] &&
+ nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]) != TUNNEL_ENCAP_NONE)
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ipgre_tap_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ __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, extack);
+}
+
+static int erspan_validate(struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ __be16 flags = 0;
+ int ret;
+
+ if (!data)
+ return 0;
+
+ ret = ipgre_tap_validate(tb, data, extack);
+ if (ret)
+ return ret;
+
+ if (data[IFLA_GRE_ERSPAN_VER] &&
+ nla_get_u8(data[IFLA_GRE_ERSPAN_VER]) == 0)
+ return 0;
+
+ /* ERSPAN type II/III should only have GRE sequence and key flag */
+ if (data[IFLA_GRE_OFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_OFLAGS]);
+ if (data[IFLA_GRE_IFLAGS])
+ flags |= nla_get_be16(data[IFLA_GRE_IFLAGS]);
+ if (!data[IFLA_GRE_COLLECT_METADATA] &&
+ flags != (GRE_SEQ | GRE_KEY))
+ return -EINVAL;
+
+ /* ERSPAN Session ID only has 10-bit. Since we reuse
+ * 32-bit key field as ID, check it's range.
+ */
+ if (data[IFLA_GRE_IKEY] &&
+ (ntohl(nla_get_be32(data[IFLA_GRE_IKEY])) & ~ID_MASK))
+ return -EINVAL;
+
+ if (data[IFLA_GRE_OKEY] &&
+ (ntohl(nla_get_be32(data[IFLA_GRE_OKEY])) & ~ID_MASK))
+ return -EINVAL;
+
+ return 0;
+}
+
+static int ipgre_netlink_parms(struct net_device *dev,
+ struct nlattr *data[],
+ struct nlattr *tb[],
+ struct ip_tunnel_parm *parms,
+ __u32 *fwmark)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ memset(parms, 0, sizeof(*parms));
+
+ parms->iph.protocol = IPPROTO_GRE;
+
+ if (!data)
+ return 0;
+
+ if (data[IFLA_GRE_LINK])
+ parms->link = nla_get_u32(data[IFLA_GRE_LINK]);
+
+ if (data[IFLA_GRE_IFLAGS])
+ parms->i_flags = gre_flags_to_tnl_flags(nla_get_be16(data[IFLA_GRE_IFLAGS]));
+
+ if (data[IFLA_GRE_OFLAGS])
+ parms->o_flags = gre_flags_to_tnl_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_in_addr(data[IFLA_GRE_LOCAL]);
+
+ if (data[IFLA_GRE_REMOTE])
+ parms->iph.daddr = nla_get_in_addr(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])) {
+ if (t->ignore_df)
+ return -EINVAL;
+ parms->iph.frag_off = htons(IP_DF);
+ }
+
+ if (data[IFLA_GRE_COLLECT_METADATA]) {
+ t->collect_md = true;
+ if (dev->type == ARPHRD_IPGRE)
+ dev->type = ARPHRD_NONE;
+ }
+
+ if (data[IFLA_GRE_IGNORE_DF]) {
+ if (nla_get_u8(data[IFLA_GRE_IGNORE_DF])
+ && (parms->iph.frag_off & htons(IP_DF)))
+ return -EINVAL;
+ t->ignore_df = !!nla_get_u8(data[IFLA_GRE_IGNORE_DF]);
+ }
+
+ if (data[IFLA_GRE_FWMARK])
+ *fwmark = nla_get_u32(data[IFLA_GRE_FWMARK]);
+
+ return 0;
+}
+
+static int erspan_netlink_parms(struct net_device *dev,
+ struct nlattr *data[],
+ struct nlattr *tb[],
+ struct ip_tunnel_parm *parms,
+ __u32 *fwmark)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ int err;
+
+ err = ipgre_netlink_parms(dev, data, tb, parms, fwmark);
+ if (err)
+ return err;
+ if (!data)
+ return 0;
+
+ if (data[IFLA_GRE_ERSPAN_VER]) {
+ t->erspan_ver = nla_get_u8(data[IFLA_GRE_ERSPAN_VER]);
+
+ if (t->erspan_ver > 2)
+ return -EINVAL;
+ }
+
+ if (t->erspan_ver == 1) {
+ if (data[IFLA_GRE_ERSPAN_INDEX]) {
+ t->index = nla_get_u32(data[IFLA_GRE_ERSPAN_INDEX]);
+ if (t->index & ~INDEX_MASK)
+ return -EINVAL;
+ }
+ } else if (t->erspan_ver == 2) {
+ if (data[IFLA_GRE_ERSPAN_DIR]) {
+ t->dir = nla_get_u8(data[IFLA_GRE_ERSPAN_DIR]);
+ if (t->dir & ~(DIR_MASK >> DIR_OFFSET))
+ return -EINVAL;
+ }
+ if (data[IFLA_GRE_ERSPAN_HWID]) {
+ t->hwid = nla_get_u16(data[IFLA_GRE_ERSPAN_HWID]);
+ if (t->hwid & ~(HWID_MASK >> HWID_OFFSET))
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/* This function returns true when ENCAP attributes are present in the nl msg */
+static bool ipgre_netlink_encap_parms(struct nlattr *data[],
+ struct ip_tunnel_encap *ipencap)
+{
+ bool ret = false;
+
+ memset(ipencap, 0, sizeof(*ipencap));
+
+ if (!data)
+ return ret;
+
+ if (data[IFLA_GRE_ENCAP_TYPE]) {
+ ret = true;
+ ipencap->type = nla_get_u16(data[IFLA_GRE_ENCAP_TYPE]);
+ }
+
+ if (data[IFLA_GRE_ENCAP_FLAGS]) {
+ ret = true;
+ ipencap->flags = nla_get_u16(data[IFLA_GRE_ENCAP_FLAGS]);
+ }
+
+ if (data[IFLA_GRE_ENCAP_SPORT]) {
+ ret = true;
+ ipencap->sport = nla_get_be16(data[IFLA_GRE_ENCAP_SPORT]);
+ }
+
+ if (data[IFLA_GRE_ENCAP_DPORT]) {
+ ret = true;
+ ipencap->dport = nla_get_be16(data[IFLA_GRE_ENCAP_DPORT]);
+ }
+
+ return ret;
+}
+
+static int gre_tap_init(struct net_device *dev)
+{
+ __gre_tunnel_init(dev);
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ netif_keep_dst(dev);
+
+ return ip_tunnel_init(dev);
+}
+
+static const struct net_device_ops gre_tap_netdev_ops = {
+ .ndo_init = gre_tap_init,
+ .ndo_uninit = ip_tunnel_uninit,
+ .ndo_start_xmit = gre_tap_xmit,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_change_mtu = ip_tunnel_change_mtu,
+ .ndo_get_stats64 = ip_tunnel_get_stats64,
+ .ndo_get_iflink = ip_tunnel_get_iflink,
+ .ndo_fill_metadata_dst = gre_fill_metadata_dst,
+};
+
+static int erspan_tunnel_init(struct net_device *dev)
+{
+ struct ip_tunnel *tunnel = netdev_priv(dev);
+
+ if (tunnel->erspan_ver == 0)
+ tunnel->tun_hlen = 4; /* 4-byte GRE hdr. */
+ else
+ tunnel->tun_hlen = 8; /* 8-byte GRE hdr. */
+
+ tunnel->parms.iph.protocol = IPPROTO_GRE;
+ tunnel->hlen = tunnel->tun_hlen + tunnel->encap_hlen +
+ erspan_hdr_len(tunnel->erspan_ver);
+
+ dev->features |= GRE_FEATURES;
+ dev->hw_features |= GRE_FEATURES;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ netif_keep_dst(dev);
+
+ return ip_tunnel_init(dev);
+}
+
+static const struct net_device_ops erspan_netdev_ops = {
+ .ndo_init = erspan_tunnel_init,
+ .ndo_uninit = ip_tunnel_uninit,
+ .ndo_start_xmit = erspan_xmit,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+ .ndo_change_mtu = ip_tunnel_change_mtu,
+ .ndo_get_stats64 = ip_tunnel_get_stats64,
+ .ndo_get_iflink = ip_tunnel_get_iflink,
+ .ndo_fill_metadata_dst = gre_fill_metadata_dst,
+};
+
+static void ipgre_tap_setup(struct net_device *dev)
+{
+ ether_setup(dev);
+ dev->max_mtu = 0;
+ dev->netdev_ops = &gre_tap_netdev_ops;
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ ip_tunnel_setup(dev, gre_tap_net_id);
+}
+
+static int
+ipgre_newlink_encap_setup(struct net_device *dev, struct nlattr *data[])
+{
+ struct ip_tunnel_encap ipencap;
+
+ if (ipgre_netlink_encap_parms(data, &ipencap)) {
+ struct ip_tunnel *t = netdev_priv(dev);
+ int err = ip_tunnel_encap_setup(t, &ipencap);
+
+ if (err < 0)
+ return err;
+ }
+
+ return 0;
+}
+
+static int ipgre_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ip_tunnel_parm p;
+ __u32 fwmark = 0;
+ int err;
+
+ err = ipgre_newlink_encap_setup(dev, data);
+ if (err)
+ return err;
+
+ err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
+ if (err < 0)
+ return err;
+ return ip_tunnel_newlink(dev, tb, &p, fwmark);
+}
+
+static int erspan_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ip_tunnel_parm p;
+ __u32 fwmark = 0;
+ int err;
+
+ err = ipgre_newlink_encap_setup(dev, data);
+ if (err)
+ return err;
+
+ err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
+ if (err)
+ return err;
+ return ip_tunnel_newlink(dev, tb, &p, fwmark);
+}
+
+static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[],
+ struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ __u32 fwmark = t->fwmark;
+ struct ip_tunnel_parm p;
+ int err;
+
+ err = ipgre_newlink_encap_setup(dev, data);
+ if (err)
+ return err;
+
+ err = ipgre_netlink_parms(dev, data, tb, &p, &fwmark);
+ if (err < 0)
+ return err;
+
+ err = ip_tunnel_changelink(dev, tb, &p, fwmark);
+ if (err < 0)
+ return err;
+
+ t->parms.i_flags = p.i_flags;
+ t->parms.o_flags = p.o_flags;
+
+ ipgre_link_update(dev, !tb[IFLA_MTU]);
+
+ return 0;
+}
+
+static int erspan_changelink(struct net_device *dev, struct nlattr *tb[],
+ struct nlattr *data[],
+ struct netlink_ext_ack *extack)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+ __u32 fwmark = t->fwmark;
+ struct ip_tunnel_parm p;
+ int err;
+
+ err = ipgre_newlink_encap_setup(dev, data);
+ if (err)
+ return err;
+
+ err = erspan_netlink_parms(dev, data, tb, &p, &fwmark);
+ if (err < 0)
+ return err;
+
+ err = ip_tunnel_changelink(dev, tb, &p, fwmark);
+ if (err < 0)
+ return err;
+
+ t->parms.i_flags = p.i_flags;
+ t->parms.o_flags = p.o_flags;
+
+ 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) +
+ /* IFLA_GRE_ENCAP_TYPE */
+ nla_total_size(2) +
+ /* IFLA_GRE_ENCAP_FLAGS */
+ nla_total_size(2) +
+ /* IFLA_GRE_ENCAP_SPORT */
+ nla_total_size(2) +
+ /* IFLA_GRE_ENCAP_DPORT */
+ nla_total_size(2) +
+ /* IFLA_GRE_COLLECT_METADATA */
+ nla_total_size(0) +
+ /* IFLA_GRE_IGNORE_DF */
+ nla_total_size(1) +
+ /* IFLA_GRE_FWMARK */
+ nla_total_size(4) +
+ /* IFLA_GRE_ERSPAN_INDEX */
+ nla_total_size(4) +
+ /* IFLA_GRE_ERSPAN_VER */
+ nla_total_size(1) +
+ /* IFLA_GRE_ERSPAN_DIR */
+ nla_total_size(1) +
+ /* IFLA_GRE_ERSPAN_HWID */
+ nla_total_size(2) +
+ 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;
+ __be16 o_flags = p->o_flags;
+
+ if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
+ nla_put_be16(skb, IFLA_GRE_IFLAGS,
+ gre_tnl_flags_to_gre_flags(p->i_flags)) ||
+ nla_put_be16(skb, IFLA_GRE_OFLAGS,
+ gre_tnl_flags_to_gre_flags(o_flags)) ||
+ nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) ||
+ nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) ||
+ nla_put_in_addr(skb, IFLA_GRE_LOCAL, p->iph.saddr) ||
+ nla_put_in_addr(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))) ||
+ nla_put_u32(skb, IFLA_GRE_FWMARK, t->fwmark))
+ goto nla_put_failure;
+
+ if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
+ t->encap.type) ||
+ nla_put_be16(skb, IFLA_GRE_ENCAP_SPORT,
+ t->encap.sport) ||
+ nla_put_be16(skb, IFLA_GRE_ENCAP_DPORT,
+ t->encap.dport) ||
+ nla_put_u16(skb, IFLA_GRE_ENCAP_FLAGS,
+ t->encap.flags))
+ goto nla_put_failure;
+
+ if (nla_put_u8(skb, IFLA_GRE_IGNORE_DF, t->ignore_df))
+ goto nla_put_failure;
+
+ if (t->collect_md) {
+ if (nla_put_flag(skb, IFLA_GRE_COLLECT_METADATA))
+ goto nla_put_failure;
+ }
+
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static int erspan_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ if (t->erspan_ver <= 2) {
+ if (t->erspan_ver != 0 && !t->collect_md)
+ t->parms.o_flags |= TUNNEL_KEY;
+
+ if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
+ goto nla_put_failure;
+
+ if (t->erspan_ver == 1) {
+ if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
+ goto nla_put_failure;
+ } else if (t->erspan_ver == 2) {
+ if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
+ goto nla_put_failure;
+ if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
+ goto nla_put_failure;
+ }
+ }
+
+ return ipgre_fill_info(skb, dev);
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static void erspan_setup(struct net_device *dev)
+{
+ struct ip_tunnel *t = netdev_priv(dev);
+
+ ether_setup(dev);
+ dev->max_mtu = 0;
+ dev->netdev_ops = &erspan_netdev_ops;
+ dev->priv_flags &= ~IFF_TX_SKB_SHARING;
+ dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+ ip_tunnel_setup(dev, erspan_net_id);
+ t->erspan_ver = 1;
+}
+
+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 = sizeof_field(struct iphdr, saddr) },
+ [IFLA_GRE_REMOTE] = { .len = sizeof_field(struct iphdr, daddr) },
+ [IFLA_GRE_TTL] = { .type = NLA_U8 },
+ [IFLA_GRE_TOS] = { .type = NLA_U8 },
+ [IFLA_GRE_PMTUDISC] = { .type = NLA_U8 },
+ [IFLA_GRE_ENCAP_TYPE] = { .type = NLA_U16 },
+ [IFLA_GRE_ENCAP_FLAGS] = { .type = NLA_U16 },
+ [IFLA_GRE_ENCAP_SPORT] = { .type = NLA_U16 },
+ [IFLA_GRE_ENCAP_DPORT] = { .type = NLA_U16 },
+ [IFLA_GRE_COLLECT_METADATA] = { .type = NLA_FLAG },
+ [IFLA_GRE_IGNORE_DF] = { .type = NLA_U8 },
+ [IFLA_GRE_FWMARK] = { .type = NLA_U32 },
+ [IFLA_GRE_ERSPAN_INDEX] = { .type = NLA_U32 },
+ [IFLA_GRE_ERSPAN_VER] = { .type = NLA_U8 },
+ [IFLA_GRE_ERSPAN_DIR] = { .type = NLA_U8 },
+ [IFLA_GRE_ERSPAN_HWID] = { .type = NLA_U16 },
+};
+
+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,
+ .dellink = ip_tunnel_dellink,
+ .get_size = ipgre_get_size,
+ .fill_info = ipgre_fill_info,
+ .get_link_net = ip_tunnel_get_link_net,
+};
+
+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,
+ .dellink = ip_tunnel_dellink,
+ .get_size = ipgre_get_size,
+ .fill_info = ipgre_fill_info,
+ .get_link_net = ip_tunnel_get_link_net,
+};
+
+static struct rtnl_link_ops erspan_link_ops __read_mostly = {
+ .kind = "erspan",
+ .maxtype = IFLA_GRE_MAX,
+ .policy = ipgre_policy,
+ .priv_size = sizeof(struct ip_tunnel),
+ .setup = erspan_setup,
+ .validate = erspan_validate,
+ .newlink = erspan_newlink,
+ .changelink = erspan_changelink,
+ .dellink = ip_tunnel_dellink,
+ .get_size = ipgre_get_size,
+ .fill_info = erspan_fill_info,
+ .get_link_net = ip_tunnel_get_link_net,
+};
+
+struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
+ u8 name_assign_type)
+{
+ struct nlattr *tb[IFLA_MAX + 1];
+ struct net_device *dev;
+ LIST_HEAD(list_kill);
+ struct ip_tunnel *t;
+ int err;
+
+ memset(&tb, 0, sizeof(tb));
+
+ dev = rtnl_create_link(net, name, name_assign_type,
+ &ipgre_tap_ops, tb, NULL);
+ if (IS_ERR(dev))
+ return dev;
+
+ /* Configure flow based GRE device. */
+ t = netdev_priv(dev);
+ t->collect_md = true;
+
+ err = ipgre_newlink(net, dev, tb, NULL, NULL);
+ if (err < 0) {
+ free_netdev(dev);
+ return ERR_PTR(err);
+ }
+
+ /* openvswitch users expect packet sizes to be unrestricted,
+ * so set the largest MTU we can.
+ */
+ err = __ip_tunnel_change_mtu(dev, IP_MAX_MTU, false);
+ if (err)
+ goto out;
+
+ err = rtnl_configure_link(dev, NULL);
+ if (err < 0)
+ goto out;
+
+ return dev;
+out:
+ ip_tunnel_dellink(dev, &list_kill);
+ unregister_netdevice_many(&list_kill);
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL_GPL(gretap_fb_dev_create);
+
+static int __net_init ipgre_tap_init_net(struct net *net)
+{
+ return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0");
+}
+
+static void __net_exit ipgre_tap_exit_batch_net(struct list_head *list_net)
+{
+ ip_tunnel_delete_nets(list_net, gre_tap_net_id, &ipgre_tap_ops);
+}
+
+static struct pernet_operations ipgre_tap_net_ops = {
+ .init = ipgre_tap_init_net,
+ .exit_batch = ipgre_tap_exit_batch_net,
+ .id = &gre_tap_net_id,
+ .size = sizeof(struct ip_tunnel_net),
+};
+
+static int __net_init erspan_init_net(struct net *net)
+{
+ return ip_tunnel_init_net(net, erspan_net_id,
+ &erspan_link_ops, "erspan0");
+}
+
+static void __net_exit erspan_exit_batch_net(struct list_head *net_list)
+{
+ ip_tunnel_delete_nets(net_list, erspan_net_id, &erspan_link_ops);
+}
+
+static struct pernet_operations erspan_net_ops = {
+ .init = erspan_init_net,
+ .exit_batch = erspan_exit_batch_net,
+ .id = &erspan_net_id,
+ .size = sizeof(struct ip_tunnel_net),
+};
+
+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 = register_pernet_device(&ipgre_tap_net_ops);
+ if (err < 0)
+ goto pnet_tap_failed;
+
+ err = register_pernet_device(&erspan_net_ops);
+ if (err < 0)
+ goto pnet_erspan_failed;
+
+ 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;
+
+ err = rtnl_link_register(&erspan_link_ops);
+ if (err < 0)
+ goto erspan_link_failed;
+
+ return 0;
+
+erspan_link_failed:
+ rtnl_link_unregister(&ipgre_tap_ops);
+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(&erspan_net_ops);
+pnet_erspan_failed:
+ unregister_pernet_device(&ipgre_tap_net_ops);
+pnet_tap_failed:
+ unregister_pernet_device(&ipgre_net_ops);
+ return err;
+}
+
+static void __exit ipgre_fini(void)
+{
+ rtnl_link_unregister(&ipgre_tap_ops);
+ rtnl_link_unregister(&ipgre_link_ops);
+ rtnl_link_unregister(&erspan_link_ops);
+ gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
+ unregister_pernet_device(&ipgre_tap_net_ops);
+ unregister_pernet_device(&ipgre_net_ops);
+ unregister_pernet_device(&erspan_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_RTNL_LINK("erspan");
+MODULE_ALIAS_NETDEV("gre0");
+MODULE_ALIAS_NETDEV("gretap0");
+MODULE_ALIAS_NETDEV("erspan0");