diff options
Diffstat (limited to 'kernel/net/ipv4/ip_gre.c')
| -rw-r--r-- | kernel/net/ipv4/ip_gre.c | 464 |
1 files changed, 432 insertions, 32 deletions
diff --git a/kernel/net/ipv4/ip_gre.c b/kernel/net/ipv4/ip_gre.c index 5fd706473..614521437 100644 --- a/kernel/net/ipv4/ip_gre.c +++ b/kernel/net/ipv4/ip_gre.c @@ -25,6 +25,7 @@ #include <linux/udp.h> #include <linux/if_arp.h> #include <linux/mroute.h> +#include <linux/if_vlan.h> #include <linux/init.h> #include <linux/in6.h> #include <linux/inetdevice.h> @@ -47,6 +48,7 @@ #include <net/netns/generic.h> #include <net/rtnetlink.h> #include <net/gre.h> +#include <net/dst_metadata.h> #if IS_ENABLED(CONFIG_IPV6) #include <net/ipv6.h> @@ -121,8 +123,127 @@ static int ipgre_tunnel_init(struct net_device *dev); static int ipgre_net_id __read_mostly; static int gre_tap_net_id __read_mostly; -static int ipgre_err(struct sk_buff *skb, u32 info, - const struct tnl_ptk_info *tpi) +static int ip_gre_calc_hlen(__be16 o_flags) +{ + int addend = 4; + + if (o_flags & TUNNEL_CSUM) + addend += 4; + if (o_flags & TUNNEL_KEY) + addend += 4; + if (o_flags & TUNNEL_SEQ) + addend += 4; + return addend; +} + +static __be16 gre_flags_to_tnl_flags(__be16 flags) +{ + __be16 tflags = 0; + + if (flags & GRE_CSUM) + tflags |= TUNNEL_CSUM; + if (flags & GRE_ROUTING) + tflags |= TUNNEL_ROUTING; + if (flags & GRE_KEY) + tflags |= TUNNEL_KEY; + if (flags & GRE_SEQ) + tflags |= TUNNEL_SEQ; + if (flags & GRE_STRICT) + tflags |= TUNNEL_STRICT; + if (flags & GRE_REC) + tflags |= TUNNEL_REC; + if (flags & GRE_VERSION) + tflags |= TUNNEL_VERSION; + + return tflags; +} + +static __be16 tnl_flags_to_gre_flags(__be16 tflags) +{ + __be16 flags = 0; + + if (tflags & TUNNEL_CSUM) + flags |= GRE_CSUM; + if (tflags & TUNNEL_ROUTING) + flags |= GRE_ROUTING; + if (tflags & TUNNEL_KEY) + flags |= GRE_KEY; + if (tflags & TUNNEL_SEQ) + flags |= GRE_SEQ; + if (tflags & TUNNEL_STRICT) + flags |= GRE_STRICT; + if (tflags & TUNNEL_REC) + flags |= GRE_REC; + if (tflags & TUNNEL_VERSION) + flags |= GRE_VERSION; + + return flags; +} + +static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, + bool *csum_err) +{ + const struct gre_base_hdr *greh; + __be32 *options; + int hdr_len; + + if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr)))) + return -EINVAL; + + greh = (struct gre_base_hdr *)skb_transport_header(skb); + if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING))) + return -EINVAL; + + tpi->flags = gre_flags_to_tnl_flags(greh->flags); + hdr_len = ip_gre_calc_hlen(tpi->flags); + + if (!pskb_may_pull(skb, hdr_len)) + return -EINVAL; + + greh = (struct gre_base_hdr *)skb_transport_header(skb); + tpi->proto = greh->protocol; + + options = (__be32 *)(greh + 1); + if (greh->flags & GRE_CSUM) { + if (skb_checksum_simple_validate(skb)) { + *csum_err = true; + return -EINVAL; + } + + skb_checksum_try_convert(skb, IPPROTO_GRE, 0, + null_compute_pseudo); + options++; + } + + if (greh->flags & GRE_KEY) { + tpi->key = *options; + options++; + } else { + tpi->key = 0; + } + if (unlikely(greh->flags & GRE_SEQ)) { + tpi->seq = *options; + options++; + } else { + tpi->seq = 0; + } + /* WCCP version 1 and 2 protocol decoding. + * - Change protocol to IP + * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header + */ + if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) { + tpi->proto = htons(ETH_P_IP); + if ((*(u8 *)options & 0xF0) != 0x40) { + hdr_len += 4; + if (!pskb_may_pull(skb, hdr_len)) + return -EINVAL; + } + } + return iptunnel_pull_header(skb, hdr_len, tpi->proto); +} + +static void ipgre_err(struct sk_buff *skb, u32 info, + const struct tnl_ptk_info *tpi) { /* All the routers (except for Linux) return only @@ -148,14 +269,14 @@ static int ipgre_err(struct sk_buff *skb, u32 info, switch (type) { default: case ICMP_PARAMETERPROB: - return PACKET_RCVD; + return; case ICMP_DEST_UNREACH: switch (code) { case ICMP_SR_FAILED: case ICMP_PORT_UNREACH: /* Impossible event. */ - return PACKET_RCVD; + return; default: /* All others are translated to HOST_UNREACH. rfc2003 contains "deep thoughts" about NET_UNREACH, @@ -164,9 +285,10 @@ static int ipgre_err(struct sk_buff *skb, u32 info, break; } break; + case ICMP_TIME_EXCEEDED: if (code != ICMP_EXC_TTL) - return PACKET_RCVD; + return; break; case ICMP_REDIRECT: @@ -183,26 +305,85 @@ static int ipgre_err(struct sk_buff *skb, u32 info, iph->daddr, iph->saddr, tpi->key); if (!t) - return PACKET_REJECT; + return; if (t->parms.iph.daddr == 0 || ipv4_is_multicast(t->parms.iph.daddr)) - return PACKET_RCVD; + return; if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED) - return PACKET_RCVD; + return; if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO)) t->err_count++; else t->err_count = 1; t->err_time = jiffies; - return PACKET_RCVD; +} + +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 int type = icmp_hdr(skb)->type; + const int code = icmp_hdr(skb)->code; + struct tnl_ptk_info tpi; + bool csum_err = false; + + if (parse_gre_header(skb, &tpi, &csum_err)) { + if (!csum_err) /* ignore csum errors. */ + 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 __be64 key_to_tunnel_id(__be32 key) +{ +#ifdef __BIG_ENDIAN + return (__force __be64)((__force u32)key); +#else + return (__force __be64)((__force u64)key << 32); +#endif +} + +/* Returns the least-significant 32 bits of a __be64. */ +static __be32 tunnel_id_to_key(__be64 x) +{ +#ifdef __BIG_ENDIAN + return (__force __be32)x; +#else + return (__force __be32)((__force u64)x >> 32); +#endif } static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) { struct net *net = dev_net(skb->dev); + struct metadata_dst *tun_dst = NULL; struct ip_tunnel_net *itn; const struct iphdr *iph; struct ip_tunnel *tunnel; @@ -218,40 +399,211 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi) if (tunnel) { skb_pop_mac_header(skb); - ip_tunnel_rcv(tunnel, skb, tpi, log_ecn_error); + if (tunnel->collect_md) { + __be16 flags; + __be64 tun_id; + + flags = tpi->flags & (TUNNEL_CSUM | TUNNEL_KEY); + tun_id = key_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_REJECT; } +static int gre_rcv(struct sk_buff *skb) +{ + struct tnl_ptk_info tpi; + bool csum_err = false; + +#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 + + if (parse_gre_header(skb, &tpi, &csum_err) < 0) + goto drop; + + if (ipgre_rcv(skb, &tpi) == PACKET_RCVD) + return 0; + + icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0); +drop: + kfree_skb(skb); + return 0; +} + +static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags, + __be16 proto, __be32 key, __be32 seq) +{ + struct gre_base_hdr *greh; + + skb_push(skb, hdr_len); + + skb_reset_transport_header(skb); + greh = (struct gre_base_hdr *)skb->data; + greh->flags = tnl_flags_to_gre_flags(flags); + greh->protocol = proto; + + if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { + __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); + + if (flags & TUNNEL_SEQ) { + *ptr = seq; + ptr--; + } + if (flags & TUNNEL_KEY) { + *ptr = key; + ptr--; + } + if (flags & TUNNEL_CSUM && + !(skb_shinfo(skb)->gso_type & + (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { + *ptr = 0; + *(__sum16 *)ptr = csum_fold(skb_checksum(skb, 0, + skb->len, 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); - struct tnl_ptk_info tpi; - tpi.flags = tunnel->parms.o_flags; - tpi.proto = proto; - tpi.key = tunnel->parms.o_key; if (tunnel->parms.o_flags & TUNNEL_SEQ) tunnel->o_seqno++; - tpi.seq = htonl(tunnel->o_seqno); /* Push GRE header. */ - gre_build_header(skb, &tpi, tunnel->tun_hlen); - - skb_set_inner_protocol(skb, tpi.proto); + build_header(skb, tunnel->tun_hlen, tunnel->parms.o_flags, + proto, tunnel->parms.o_key, htonl(tunnel->o_seqno)); + skb_set_inner_protocol(skb, proto); ip_tunnel_xmit(skb, dev, tnl_params, tnl_params->protocol); } +static struct sk_buff *gre_handle_offloads(struct sk_buff *skb, + bool csum) +{ + return iptunnel_handle_offloads(skb, csum, + 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 void gre_fb_xmit(struct sk_buff *skb, struct net_device *dev) +{ + struct ip_tunnel_info *tun_info; + const struct ip_tunnel_key *key; + struct flowi4 fl; + struct rtable *rt; + int min_headroom; + int tunnel_hlen; + __be16 df, flags; + int err; + + 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; + rt = gre_get_rt(skb, dev, &fl, key); + if (IS_ERR(rt)) + goto err_free_skb; + + tunnel_hlen = ip_gre_calc_hlen(key->tun_flags); + + 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; + } + + /* Push Tunnel header. */ + skb = gre_handle_offloads(skb, !!(tun_info->key.tun_flags & TUNNEL_CSUM)); + if (IS_ERR(skb)) { + skb = NULL; + goto err_free_rt; + } + + flags = tun_info->key.tun_flags & (TUNNEL_CSUM | TUNNEL_KEY); + build_header(skb, tunnel_hlen, flags, htons(ETH_P_TEB), + tunnel_id_to_key(tun_info->key.tun_id), 0); + + df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0; + err = iptunnel_xmit(skb->sk, rt, skb, fl.saddr, + key->u.ipv4.dst, IPPROTO_GRE, + key->tos, key->ttl, df, false); + iptunnel_xmit_stats(err, &dev->stats, dev->tstats); + 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 (tunnel->collect_md) { + gre_fb_xmit(skb, dev); + return NETDEV_TX_OK; + } + if (dev->header_ops) { /* Need space for new headers */ if (skb_cow_head(skb, dev->needed_headroom - @@ -277,7 +629,6 @@ static netdev_tx_t ipgre_xmit(struct sk_buff *skb, goto out; __gre_xmit(skb, dev, tnl_params, skb->protocol); - return NETDEV_TX_OK; free_skb: @@ -292,6 +643,11 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, { struct ip_tunnel *tunnel = netdev_priv(dev); + if (tunnel->collect_md) { + gre_fb_xmit(skb, dev); + return NETDEV_TX_OK; + } + skb = gre_handle_offloads(skb, !!(tunnel->parms.o_flags&TUNNEL_CSUM)); if (IS_ERR(skb)) goto out; @@ -300,7 +656,6 @@ static netdev_tx_t gre_tap_xmit(struct sk_buff *skb, goto free_skb; __gre_xmit(skb, dev, &tunnel->parms.iph, htons(ETH_P_TEB)); - return NETDEV_TX_OK; free_skb: @@ -530,10 +885,9 @@ static int ipgre_tunnel_init(struct net_device *dev) return ip_tunnel_init(dev); } -static struct gre_cisco_protocol ipgre_protocol = { - .handler = ipgre_rcv, - .err_handler = ipgre_err, - .priority = 0, +static const struct gre_protocol ipgre_protocol = { + .handler = gre_rcv, + .err_handler = gre_err, }; static int __net_init ipgre_init_net(struct net *net) @@ -596,8 +950,10 @@ out: return ipgre_tunnel_validate(tb, data); } -static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], - struct ip_tunnel_parm *parms) +static void ipgre_netlink_parms(struct net_device *dev, + struct nlattr *data[], + struct nlattr *tb[], + struct ip_tunnel_parm *parms) { memset(parms, 0, sizeof(*parms)); @@ -635,6 +991,12 @@ static void ipgre_netlink_parms(struct nlattr *data[], struct nlattr *tb[], if (!data[IFLA_GRE_PMTUDISC] || nla_get_u8(data[IFLA_GRE_PMTUDISC])) parms->iph.frag_off = htons(IP_DF); + + if (data[IFLA_GRE_COLLECT_METADATA]) { + struct ip_tunnel *t = netdev_priv(dev); + + t->collect_md = true; + } } /* This function returns true when ENCAP attributes are present in the nl msg */ @@ -688,6 +1050,7 @@ static const struct net_device_ops gre_tap_netdev_ops = { .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) @@ -712,7 +1075,7 @@ static int ipgre_newlink(struct net *src_net, struct net_device *dev, return err; } - ipgre_netlink_parms(data, tb, &p); + ipgre_netlink_parms(dev, data, tb, &p); return ip_tunnel_newlink(dev, tb, &p); } @@ -730,7 +1093,7 @@ static int ipgre_changelink(struct net_device *dev, struct nlattr *tb[], return err; } - ipgre_netlink_parms(data, tb, &p); + ipgre_netlink_parms(dev, data, tb, &p); return ip_tunnel_changelink(dev, tb, &p); } @@ -765,6 +1128,8 @@ static size_t ipgre_get_size(const struct net_device *dev) nla_total_size(2) + /* IFLA_GRE_ENCAP_DPORT */ nla_total_size(2) + + /* IFLA_GRE_COLLECT_METADATA */ + nla_total_size(0) + 0; } @@ -796,6 +1161,11 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev) t->encap.flags)) 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: @@ -817,6 +1187,7 @@ static const struct nla_policy ipgre_policy[IFLA_GRE_MAX + 1] = { [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 }, }; static struct rtnl_link_ops ipgre_link_ops __read_mostly = { @@ -849,9 +1220,38 @@ static struct rtnl_link_ops ipgre_tap_ops __read_mostly = { .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; + 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); + if (err < 0) + goto out; + return dev; +out: + free_netdev(dev); + 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, NULL); + return ip_tunnel_init_net(net, gre_tap_net_id, &ipgre_tap_ops, "gretap0"); } static void __net_exit ipgre_tap_exit_net(struct net *net) @@ -881,7 +1281,7 @@ static int __init ipgre_init(void) if (err < 0) goto pnet_tap_faied; - err = gre_cisco_register(&ipgre_protocol); + err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO); if (err < 0) { pr_info("%s: can't add protocol\n", __func__); goto add_proto_failed; @@ -900,7 +1300,7 @@ static int __init ipgre_init(void) tap_ops_failed: rtnl_link_unregister(&ipgre_link_ops); rtnl_link_failed: - gre_cisco_unregister(&ipgre_protocol); + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); add_proto_failed: unregister_pernet_device(&ipgre_tap_net_ops); pnet_tap_faied: @@ -912,7 +1312,7 @@ static void __exit ipgre_fini(void) { rtnl_link_unregister(&ipgre_tap_ops); rtnl_link_unregister(&ipgre_link_ops); - gre_cisco_unregister(&ipgre_protocol); + gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO); unregister_pernet_device(&ipgre_tap_net_ops); unregister_pernet_device(&ipgre_net_ops); } |