diff options
Diffstat (limited to 'net/ipv4/ip_gre.c')
| -rw-r--r-- | net/ipv4/ip_gre.c | 1839 |
1 files changed, 1839 insertions, 0 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c new file mode 100644 index 000000000..cf60d0e07 --- /dev/null +++ b/net/ipv4/ip_gre.c @@ -0,0 +1,1839 @@ +/* + * 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 <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 void 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; + + switch (type) { + default: + case ICMP_PARAMETERPROB: + return; + + case ICMP_DEST_UNREACH: + switch (code) { + case ICMP_SR_FAILED: + case ICMP_PORT_UNREACH: + /* Impossible event. */ + 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; + data_len = icmp_hdr(skb)->un.reserved[1] * 4; /* RFC 4884 4.1 */ + break; + + case ICMP_REDIRECT: + break; + } + + 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; + +#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; +#endif + + if (t->parms.iph.daddr == 0 || + ipv4_is_multicast(t->parms.iph.daddr)) + return; + + if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) + return; + + if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) + t->err_count++; + else + t->err_count = 1; + t->err_time = jiffies; +} + +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, 0, IPPROTO_GRE, 0); + return; + } + if (type == ICMP_REDIRECT) { + ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0, + IPPROTO_GRE, 0); + return; + } + + ipgre_err(skb, info, &tpi); +} + +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); + 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) { + 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) { + 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); + if (tunnel->collect_md) { + __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(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 struct rtable *gre_get_rt(struct sk_buff *skb, + struct net_device *dev, + struct flowi4 *fl, + const struct ip_tunnel_key *key) +{ + struct net *net = dev_net(dev); + + memset(fl, 0, sizeof(*fl)); + fl->daddr = key->u.ipv4.dst; + fl->saddr = key->u.ipv4.src; + fl->flowi4_tos = RT_TOS(key->tos); + fl->flowi4_mark = skb->mark; + fl->flowi4_proto = IPPROTO_GRE; + + return ip_route_output_key(net, fl); +} + +static struct rtable *prepare_fb_xmit(struct sk_buff *skb, + struct net_device *dev, + struct flowi4 *fl, + int tunnel_hlen) +{ + struct ip_tunnel_info *tun_info; + const struct ip_tunnel_key *key; + struct rtable *rt = NULL; + int min_headroom; + bool use_cache; + int err; + + tun_info = skb_tunnel_info(skb); + key = &tun_info->key; + use_cache = ip_tunnel_dst_cache_usable(skb, tun_info); + + if (use_cache) + rt = dst_cache_get_ip4(&tun_info->dst_cache, &fl->saddr); + if (!rt) { + rt = gre_get_rt(skb, dev, fl, key); + if (IS_ERR(rt)) + goto err_free_skb; + if (use_cache) + dst_cache_set_ip4(&tun_info->dst_cache, &rt->dst, + fl->saddr); + } + + min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len + + tunnel_hlen + sizeof(struct iphdr); + if (skb_headroom(skb) < min_headroom || skb_header_cloned(skb)) { + int head_delta = SKB_DATA_ALIGN(min_headroom - + skb_headroom(skb) + + 16); + err = pskb_expand_head(skb, max_t(int, head_delta, 0), + 0, GFP_ATOMIC); + if (unlikely(err)) + goto err_free_rt; + } + return rt; + +err_free_rt: + ip_rt_put(rt); +err_free_skb: + kfree_skb(skb); + dev->stats.tx_dropped++; + return NULL; +} + +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; + struct rtable *rt = NULL; + struct flowi4 fl; + int tunnel_hlen; + __be16 df, 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); + + rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); + if (!rt) + return; + + /* Push Tunnel header. */ + if (gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM))) + goto err_free_rt; + + 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(tunnel->o_seqno++) : 0); + + df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; + + iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, + key->tos, key->ttl, df, false); + return; + +err_free_rt: + ip_rt_put(rt); +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; + struct rtable *rt = NULL; + bool truncate = false; + __be16 df, proto; + struct flowi4 fl; + int tunnel_hlen; + int version; + int nhoff; + int thoff; + + 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_rt; + if (tun_info->options_len < sizeof(*md)) + goto err_free_rt; + md = ip_tunnel_info_opts(tun_info); + + /* ERSPAN has fixed 8 byte GRE header */ + version = md->version; + tunnel_hlen = 8 + erspan_hdr_len(version); + + rt = prepare_fb_xmit(skb, dev, &fl, tunnel_hlen); + if (!rt) + return; + + if (gre_handle_offloads(skb, false)) + goto err_free_rt; + + if (skb->len > dev->mtu + dev->hard_header_len) { + pskb_trim(skb, dev->mtu + dev->hard_header_len); + truncate = true; + } + + nhoff = skb_network_header(skb) - skb_mac_header(skb); + if (skb->protocol == htons(ETH_P_IP) && + (ntohs(ip_hdr(skb)->tot_len) > skb->len - nhoff)) + truncate = true; + + thoff = skb_transport_header(skb) - skb_mac_header(skb); + if (skb->protocol == htons(ETH_P_IPV6) && + (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_rt; + } + + gre_build_header(skb, 8, TUNNEL_SEQ, + proto, 0, htonl(tunnel->o_seqno++)); + + df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; + + iptunnel_xmit(skb->sk, rt, skb, fl.saddr, key->u.ipv4.dst, IPPROTO_GRE, + key->tos, key->ttl, df, false); + return; + +err_free_rt: + ip_rt_put(rt); +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); + struct rtable *rt; + struct flowi4 fl4; + + if (ip_tunnel_info_af(info) != AF_INET) + return -EINVAL; + + rt = gre_get_rt(skb, dev, &fl4, &info->key); + 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) { + if (skb_cow_head(skb, 0)) + goto free_skb; + + tnl_params = (const struct iphdr *)skb->data; + + /* Pull skb since ip_tunnel_xmit() needs skb->data pointing + * to gre header. + */ + skb_pull(skb, tunnel->hlen + sizeof(struct iphdr)); + 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 == 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_ioctl(struct net_device *dev, + struct ifreq *ifr, int cmd) +{ + struct ip_tunnel_parm p; + int err; + + if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p))) + return -EFAULT; + + 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_ioctl(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); + + if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p))) + return -EFAULT; + + 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 = ipgre_tunnel_ioctl, + .ndo_change_mtu = ip_tunnel_change_mtu, + .ndo_get_stats64 = ip_tunnel_get_stats64, + .ndo_get_iflink = ip_tunnel_get_iflink, +}; + +#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; + + /* ERSPAN 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 != 1 && 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); + + tunnel->tun_hlen = 8; + 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); +} + +bool is_gretap_dev(const struct net_device *dev) +{ + return dev->netdev_ops == &gre_tap_netdev_ops; +} +EXPORT_SYMBOL_GPL(is_gretap_dev); + +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 (t->erspan_ver == 1 || t->erspan_ver == 2) { + if (!t->collect_md) + 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 (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; + } + } + + 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 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 = 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 }, + [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 = ipgre_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); + 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"); |