linux/net/ipv4/ip_tunnel_core.c
Eric Dumazet 853a761488 tunnels: do not assume mac header is set in skb_tunnel_check_pmtu()
Recently added debug in commit f9aefd6b2a ("net: warn if mac header
was not set") caught a bug in skb_tunnel_check_pmtu(), as shown
in this syzbot report [1].

In ndo_start_xmit() paths, there is really no need to use skb->mac_header,
because skb->data is supposed to point at it.

[1] WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_mac_header_len include/linux/skbuff.h:2784 [inline]
WARNING: CPU: 1 PID: 8604 at include/linux/skbuff.h:2784 skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413
Modules linked in:
CPU: 1 PID: 8604 Comm: syz-executor.3 Not tainted 5.19.0-rc2-syzkaller-00443-g8720bd951b8e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:skb_mac_header_len include/linux/skbuff.h:2784 [inline]
RIP: 0010:skb_tunnel_check_pmtu+0x5de/0x2f90 net/ipv4/ip_tunnel_core.c:413
Code: 00 00 00 00 fc ff df 4c 89 fa 48 c1 ea 03 80 3c 02 00 0f 84 b9 fe ff ff 4c 89 ff e8 7c 0f d7 f9 e9 ac fe ff ff e8 c2 13 8a f9 <0f> 0b e9 28 fc ff ff e8 b6 13 8a f9 48 8b 54 24 70 48 b8 00 00 00
RSP: 0018:ffffc90002e4f520 EFLAGS: 00010212
RAX: 0000000000000324 RBX: ffff88804d5fd500 RCX: ffffc90005b52000
RDX: 0000000000040000 RSI: ffffffff87f05e3e RDI: 0000000000000003
RBP: ffffc90002e4f650 R08: 0000000000000003 R09: 000000000000ffff
R10: 000000000000ffff R11: 0000000000000000 R12: 000000000000ffff
R13: 0000000000000000 R14: 000000000000ffcd R15: 000000000000001f
FS: 00007f3babba9700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000080 CR3: 0000000075319000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
geneve_xmit_skb drivers/net/geneve.c:927 [inline]
geneve_xmit+0xcf8/0x35d0 drivers/net/geneve.c:1107
__netdev_start_xmit include/linux/netdevice.h:4805 [inline]
netdev_start_xmit include/linux/netdevice.h:4819 [inline]
__dev_direct_xmit+0x500/0x730 net/core/dev.c:4309
dev_direct_xmit include/linux/netdevice.h:3007 [inline]
packet_direct_xmit+0x1b8/0x2c0 net/packet/af_packet.c:282
packet_snd net/packet/af_packet.c:3073 [inline]
packet_sendmsg+0x21f4/0x55d0 net/packet/af_packet.c:3104
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2489
___sys_sendmsg+0xf3/0x170 net/socket.c:2543
__sys_sendmsg net/socket.c:2572 [inline]
__do_sys_sendmsg net/socket.c:2581 [inline]
__se_sys_sendmsg net/socket.c:2579 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2579
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f3baaa89109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f3babba9168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3baab9bf60 RCX: 00007f3baaa89109
RDX: 0000000000000000 RSI: 0000000020000a00 RDI: 0000000000000003
RBP: 00007f3baaae305d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe74f2543f R14: 00007f3babba9300 R15: 0000000000022000
</TASK>

Fixes: 4cb47a8644 ("tunnels: PMTU discovery support for directly bridged IP packets")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-06-27 11:50:30 +01:00

1082 lines
29 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2013 Nicira, Inc.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/in.h>
#include <linux/if_arp.h>
#include <linux/init.h>
#include <linux/in6.h>
#include <linux/inetdevice.h>
#include <linux/netfilter_ipv4.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/static_key.h>
#include <net/ip.h>
#include <net/icmp.h>
#include <net/protocol.h>
#include <net/ip_tunnels.h>
#include <net/ip6_tunnel.h>
#include <net/ip6_checksum.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/dst_metadata.h>
#include <net/geneve.h>
#include <net/vxlan.h>
#include <net/erspan.h>
const struct ip_tunnel_encap_ops __rcu *
iptun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
EXPORT_SYMBOL(iptun_encaps);
const struct ip6_tnl_encap_ops __rcu *
ip6tun_encaps[MAX_IPTUN_ENCAP_OPS] __read_mostly;
EXPORT_SYMBOL(ip6tun_encaps);
void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
__be32 src, __be32 dst, __u8 proto,
__u8 tos, __u8 ttl, __be16 df, bool xnet)
{
int pkt_len = skb->len - skb_inner_network_offset(skb);
struct net *net = dev_net(rt->dst.dev);
struct net_device *dev = skb->dev;
struct iphdr *iph;
int err;
skb_scrub_packet(skb, xnet);
skb_clear_hash_if_not_l4(skb);
skb_dst_set(skb, &rt->dst);
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
/* Push down and install the IP header. */
skb_push(skb, sizeof(struct iphdr));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
iph->version = 4;
iph->ihl = sizeof(struct iphdr) >> 2;
iph->frag_off = ip_mtu_locked(&rt->dst) ? 0 : df;
iph->protocol = proto;
iph->tos = tos;
iph->daddr = dst;
iph->saddr = src;
iph->ttl = ttl;
__ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
err = ip_local_out(net, sk, skb);
if (dev) {
if (unlikely(net_xmit_eval(err)))
pkt_len = 0;
iptunnel_xmit_stats(dev, pkt_len);
}
}
EXPORT_SYMBOL_GPL(iptunnel_xmit);
int __iptunnel_pull_header(struct sk_buff *skb, int hdr_len,
__be16 inner_proto, bool raw_proto, bool xnet)
{
if (unlikely(!pskb_may_pull(skb, hdr_len)))
return -ENOMEM;
skb_pull_rcsum(skb, hdr_len);
if (!raw_proto && inner_proto == htons(ETH_P_TEB)) {
struct ethhdr *eh;
if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
return -ENOMEM;
eh = (struct ethhdr *)skb->data;
if (likely(eth_proto_is_802_3(eh->h_proto)))
skb->protocol = eh->h_proto;
else
skb->protocol = htons(ETH_P_802_2);
} else {
skb->protocol = inner_proto;
}
skb_clear_hash_if_not_l4(skb);
__vlan_hwaccel_clear_tag(skb);
skb_set_queue_mapping(skb, 0);
skb_scrub_packet(skb, xnet);
return iptunnel_pull_offloads(skb);
}
EXPORT_SYMBOL_GPL(__iptunnel_pull_header);
struct metadata_dst *iptunnel_metadata_reply(struct metadata_dst *md,
gfp_t flags)
{
struct metadata_dst *res;
struct ip_tunnel_info *dst, *src;
if (!md || md->type != METADATA_IP_TUNNEL ||
md->u.tun_info.mode & IP_TUNNEL_INFO_TX)
return NULL;
src = &md->u.tun_info;
res = metadata_dst_alloc(src->options_len, METADATA_IP_TUNNEL, flags);
if (!res)
return NULL;
dst = &res->u.tun_info;
dst->key.tun_id = src->key.tun_id;
if (src->mode & IP_TUNNEL_INFO_IPV6)
memcpy(&dst->key.u.ipv6.dst, &src->key.u.ipv6.src,
sizeof(struct in6_addr));
else
dst->key.u.ipv4.dst = src->key.u.ipv4.src;
dst->key.tun_flags = src->key.tun_flags;
dst->mode = src->mode | IP_TUNNEL_INFO_TX;
ip_tunnel_info_opts_set(dst, ip_tunnel_info_opts(src),
src->options_len, 0);
return res;
}
EXPORT_SYMBOL_GPL(iptunnel_metadata_reply);
int iptunnel_handle_offloads(struct sk_buff *skb,
int gso_type_mask)
{
int err;
if (likely(!skb->encapsulation)) {
skb_reset_inner_headers(skb);
skb->encapsulation = 1;
}
if (skb_is_gso(skb)) {
err = skb_header_unclone(skb, GFP_ATOMIC);
if (unlikely(err))
return err;
skb_shinfo(skb)->gso_type |= gso_type_mask;
return 0;
}
if (skb->ip_summed != CHECKSUM_PARTIAL) {
skb->ip_summed = CHECKSUM_NONE;
/* We clear encapsulation here to prevent badly-written
* drivers potentially deciding to offload an inner checksum
* if we set CHECKSUM_PARTIAL on the outer header.
* This should go away when the drivers are all fixed.
*/
skb->encapsulation = 0;
}
return 0;
}
EXPORT_SYMBOL_GPL(iptunnel_handle_offloads);
/**
* iptunnel_pmtud_build_icmp() - Build ICMP error message for PMTUD
* @skb: Original packet with L2 header
* @mtu: MTU value for ICMP error
*
* Return: length on success, negative error code if message couldn't be built.
*/
static int iptunnel_pmtud_build_icmp(struct sk_buff *skb, int mtu)
{
const struct iphdr *iph = ip_hdr(skb);
struct icmphdr *icmph;
struct iphdr *niph;
struct ethhdr eh;
int len, err;
if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
return -EINVAL;
skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
pskb_pull(skb, ETH_HLEN);
skb_reset_network_header(skb);
err = pskb_trim(skb, 576 - sizeof(*niph) - sizeof(*icmph));
if (err)
return err;
len = skb->len + sizeof(*icmph);
err = skb_cow(skb, sizeof(*niph) + sizeof(*icmph) + ETH_HLEN);
if (err)
return err;
icmph = skb_push(skb, sizeof(*icmph));
*icmph = (struct icmphdr) {
.type = ICMP_DEST_UNREACH,
.code = ICMP_FRAG_NEEDED,
.checksum = 0,
.un.frag.__unused = 0,
.un.frag.mtu = htons(mtu),
};
icmph->checksum = ip_compute_csum(icmph, len);
skb_reset_transport_header(skb);
niph = skb_push(skb, sizeof(*niph));
*niph = (struct iphdr) {
.ihl = sizeof(*niph) / 4u,
.version = 4,
.tos = 0,
.tot_len = htons(len + sizeof(*niph)),
.id = 0,
.frag_off = htons(IP_DF),
.ttl = iph->ttl,
.protocol = IPPROTO_ICMP,
.saddr = iph->daddr,
.daddr = iph->saddr,
};
ip_send_check(niph);
skb_reset_network_header(skb);
skb->ip_summed = CHECKSUM_NONE;
eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
skb_reset_mac_header(skb);
return skb->len;
}
/**
* iptunnel_pmtud_check_icmp() - Trigger ICMP reply if needed and allowed
* @skb: Buffer being sent by encapsulation, L2 headers expected
* @mtu: Network MTU for path
*
* Return: 0 for no ICMP reply, length if built, negative value on error.
*/
static int iptunnel_pmtud_check_icmp(struct sk_buff *skb, int mtu)
{
const struct icmphdr *icmph = icmp_hdr(skb);
const struct iphdr *iph = ip_hdr(skb);
if (mtu < 576 || iph->frag_off != htons(IP_DF))
return 0;
if (ipv4_is_lbcast(iph->daddr) || ipv4_is_multicast(iph->daddr) ||
ipv4_is_zeronet(iph->saddr) || ipv4_is_loopback(iph->saddr) ||
ipv4_is_lbcast(iph->saddr) || ipv4_is_multicast(iph->saddr))
return 0;
if (iph->protocol == IPPROTO_ICMP && icmp_is_err(icmph->type))
return 0;
return iptunnel_pmtud_build_icmp(skb, mtu);
}
#if IS_ENABLED(CONFIG_IPV6)
/**
* iptunnel_pmtud_build_icmpv6() - Build ICMPv6 error message for PMTUD
* @skb: Original packet with L2 header
* @mtu: MTU value for ICMPv6 error
*
* Return: length on success, negative error code if message couldn't be built.
*/
static int iptunnel_pmtud_build_icmpv6(struct sk_buff *skb, int mtu)
{
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
struct icmp6hdr *icmp6h;
struct ipv6hdr *nip6h;
struct ethhdr eh;
int len, err;
__wsum csum;
if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
return -EINVAL;
skb_copy_bits(skb, skb_mac_offset(skb), &eh, ETH_HLEN);
pskb_pull(skb, ETH_HLEN);
skb_reset_network_header(skb);
err = pskb_trim(skb, IPV6_MIN_MTU - sizeof(*nip6h) - sizeof(*icmp6h));
if (err)
return err;
len = skb->len + sizeof(*icmp6h);
err = skb_cow(skb, sizeof(*nip6h) + sizeof(*icmp6h) + ETH_HLEN);
if (err)
return err;
icmp6h = skb_push(skb, sizeof(*icmp6h));
*icmp6h = (struct icmp6hdr) {
.icmp6_type = ICMPV6_PKT_TOOBIG,
.icmp6_code = 0,
.icmp6_cksum = 0,
.icmp6_mtu = htonl(mtu),
};
skb_reset_transport_header(skb);
nip6h = skb_push(skb, sizeof(*nip6h));
*nip6h = (struct ipv6hdr) {
.priority = 0,
.version = 6,
.flow_lbl = { 0 },
.payload_len = htons(len),
.nexthdr = IPPROTO_ICMPV6,
.hop_limit = ip6h->hop_limit,
.saddr = ip6h->daddr,
.daddr = ip6h->saddr,
};
skb_reset_network_header(skb);
csum = csum_partial(icmp6h, len, 0);
icmp6h->icmp6_cksum = csum_ipv6_magic(&nip6h->saddr, &nip6h->daddr, len,
IPPROTO_ICMPV6, csum);
skb->ip_summed = CHECKSUM_NONE;
eth_header(skb, skb->dev, ntohs(eh.h_proto), eh.h_source, eh.h_dest, 0);
skb_reset_mac_header(skb);
return skb->len;
}
/**
* iptunnel_pmtud_check_icmpv6() - Trigger ICMPv6 reply if needed and allowed
* @skb: Buffer being sent by encapsulation, L2 headers expected
* @mtu: Network MTU for path
*
* Return: 0 for no ICMPv6 reply, length if built, negative value on error.
*/
static int iptunnel_pmtud_check_icmpv6(struct sk_buff *skb, int mtu)
{
const struct ipv6hdr *ip6h = ipv6_hdr(skb);
int stype = ipv6_addr_type(&ip6h->saddr);
u8 proto = ip6h->nexthdr;
__be16 frag_off;
int offset;
if (mtu < IPV6_MIN_MTU)
return 0;
if (stype == IPV6_ADDR_ANY || stype == IPV6_ADDR_MULTICAST ||
stype == IPV6_ADDR_LOOPBACK)
return 0;
offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &proto,
&frag_off);
if (offset < 0 || (frag_off & htons(~0x7)))
return 0;
if (proto == IPPROTO_ICMPV6) {
struct icmp6hdr *icmp6h;
if (!pskb_may_pull(skb, skb_network_header(skb) +
offset + 1 - skb->data))
return 0;
icmp6h = (struct icmp6hdr *)(skb_network_header(skb) + offset);
if (icmpv6_is_err(icmp6h->icmp6_type) ||
icmp6h->icmp6_type == NDISC_REDIRECT)
return 0;
}
return iptunnel_pmtud_build_icmpv6(skb, mtu);
}
#endif /* IS_ENABLED(CONFIG_IPV6) */
/**
* skb_tunnel_check_pmtu() - Check, update PMTU and trigger ICMP reply as needed
* @skb: Buffer being sent by encapsulation, L2 headers expected
* @encap_dst: Destination for tunnel encapsulation (outer IP)
* @headroom: Encapsulation header size, bytes
* @reply: Build matching ICMP or ICMPv6 message as a result
*
* L2 tunnel implementations that can carry IP and can be directly bridged
* (currently UDP tunnels) can't always rely on IP forwarding paths to handle
* PMTU discovery. In the bridged case, ICMP or ICMPv6 messages need to be built
* based on payload and sent back by the encapsulation itself.
*
* For routable interfaces, we just need to update the PMTU for the destination.
*
* Return: 0 if ICMP error not needed, length if built, negative value on error
*/
int skb_tunnel_check_pmtu(struct sk_buff *skb, struct dst_entry *encap_dst,
int headroom, bool reply)
{
u32 mtu = dst_mtu(encap_dst) - headroom;
if ((skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) ||
(!skb_is_gso(skb) && (skb->len - skb_network_offset(skb)) <= mtu))
return 0;
skb_dst_update_pmtu_no_confirm(skb, mtu);
if (!reply || skb->pkt_type == PACKET_HOST)
return 0;
if (skb->protocol == htons(ETH_P_IP))
return iptunnel_pmtud_check_icmp(skb, mtu);
#if IS_ENABLED(CONFIG_IPV6)
if (skb->protocol == htons(ETH_P_IPV6))
return iptunnel_pmtud_check_icmpv6(skb, mtu);
#endif
return 0;
}
EXPORT_SYMBOL(skb_tunnel_check_pmtu);
static const struct nla_policy ip_tun_policy[LWTUNNEL_IP_MAX + 1] = {
[LWTUNNEL_IP_UNSPEC] = { .strict_start_type = LWTUNNEL_IP_OPTS },
[LWTUNNEL_IP_ID] = { .type = NLA_U64 },
[LWTUNNEL_IP_DST] = { .type = NLA_U32 },
[LWTUNNEL_IP_SRC] = { .type = NLA_U32 },
[LWTUNNEL_IP_TTL] = { .type = NLA_U8 },
[LWTUNNEL_IP_TOS] = { .type = NLA_U8 },
[LWTUNNEL_IP_FLAGS] = { .type = NLA_U16 },
[LWTUNNEL_IP_OPTS] = { .type = NLA_NESTED },
};
static const struct nla_policy ip_opts_policy[LWTUNNEL_IP_OPTS_MAX + 1] = {
[LWTUNNEL_IP_OPTS_GENEVE] = { .type = NLA_NESTED },
[LWTUNNEL_IP_OPTS_VXLAN] = { .type = NLA_NESTED },
[LWTUNNEL_IP_OPTS_ERSPAN] = { .type = NLA_NESTED },
};
static const struct nla_policy
geneve_opt_policy[LWTUNNEL_IP_OPT_GENEVE_MAX + 1] = {
[LWTUNNEL_IP_OPT_GENEVE_CLASS] = { .type = NLA_U16 },
[LWTUNNEL_IP_OPT_GENEVE_TYPE] = { .type = NLA_U8 },
[LWTUNNEL_IP_OPT_GENEVE_DATA] = { .type = NLA_BINARY, .len = 128 },
};
static const struct nla_policy
vxlan_opt_policy[LWTUNNEL_IP_OPT_VXLAN_MAX + 1] = {
[LWTUNNEL_IP_OPT_VXLAN_GBP] = { .type = NLA_U32 },
};
static const struct nla_policy
erspan_opt_policy[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1] = {
[LWTUNNEL_IP_OPT_ERSPAN_VER] = { .type = NLA_U8 },
[LWTUNNEL_IP_OPT_ERSPAN_INDEX] = { .type = NLA_U32 },
[LWTUNNEL_IP_OPT_ERSPAN_DIR] = { .type = NLA_U8 },
[LWTUNNEL_IP_OPT_ERSPAN_HWID] = { .type = NLA_U8 },
};
static int ip_tun_parse_opts_geneve(struct nlattr *attr,
struct ip_tunnel_info *info, int opts_len,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[LWTUNNEL_IP_OPT_GENEVE_MAX + 1];
int data_len, err;
err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_GENEVE_MAX, attr,
geneve_opt_policy, extack);
if (err)
return err;
if (!tb[LWTUNNEL_IP_OPT_GENEVE_CLASS] ||
!tb[LWTUNNEL_IP_OPT_GENEVE_TYPE] ||
!tb[LWTUNNEL_IP_OPT_GENEVE_DATA])
return -EINVAL;
attr = tb[LWTUNNEL_IP_OPT_GENEVE_DATA];
data_len = nla_len(attr);
if (data_len % 4)
return -EINVAL;
if (info) {
struct geneve_opt *opt = ip_tunnel_info_opts(info) + opts_len;
memcpy(opt->opt_data, nla_data(attr), data_len);
opt->length = data_len / 4;
attr = tb[LWTUNNEL_IP_OPT_GENEVE_CLASS];
opt->opt_class = nla_get_be16(attr);
attr = tb[LWTUNNEL_IP_OPT_GENEVE_TYPE];
opt->type = nla_get_u8(attr);
info->key.tun_flags |= TUNNEL_GENEVE_OPT;
}
return sizeof(struct geneve_opt) + data_len;
}
static int ip_tun_parse_opts_vxlan(struct nlattr *attr,
struct ip_tunnel_info *info, int opts_len,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[LWTUNNEL_IP_OPT_VXLAN_MAX + 1];
int err;
err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_VXLAN_MAX, attr,
vxlan_opt_policy, extack);
if (err)
return err;
if (!tb[LWTUNNEL_IP_OPT_VXLAN_GBP])
return -EINVAL;
if (info) {
struct vxlan_metadata *md =
ip_tunnel_info_opts(info) + opts_len;
attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
md->gbp = nla_get_u32(attr);
md->gbp &= VXLAN_GBP_MASK;
info->key.tun_flags |= TUNNEL_VXLAN_OPT;
}
return sizeof(struct vxlan_metadata);
}
static int ip_tun_parse_opts_erspan(struct nlattr *attr,
struct ip_tunnel_info *info, int opts_len,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[LWTUNNEL_IP_OPT_ERSPAN_MAX + 1];
int err;
u8 ver;
err = nla_parse_nested(tb, LWTUNNEL_IP_OPT_ERSPAN_MAX, attr,
erspan_opt_policy, extack);
if (err)
return err;
if (!tb[LWTUNNEL_IP_OPT_ERSPAN_VER])
return -EINVAL;
ver = nla_get_u8(tb[LWTUNNEL_IP_OPT_ERSPAN_VER]);
if (ver == 1) {
if (!tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX])
return -EINVAL;
} else if (ver == 2) {
if (!tb[LWTUNNEL_IP_OPT_ERSPAN_DIR] ||
!tb[LWTUNNEL_IP_OPT_ERSPAN_HWID])
return -EINVAL;
} else {
return -EINVAL;
}
if (info) {
struct erspan_metadata *md =
ip_tunnel_info_opts(info) + opts_len;
md->version = ver;
if (ver == 1) {
attr = tb[LWTUNNEL_IP_OPT_ERSPAN_INDEX];
md->u.index = nla_get_be32(attr);
} else {
attr = tb[LWTUNNEL_IP_OPT_ERSPAN_DIR];
md->u.md2.dir = nla_get_u8(attr);
attr = tb[LWTUNNEL_IP_OPT_ERSPAN_HWID];
set_hwid(&md->u.md2, nla_get_u8(attr));
}
info->key.tun_flags |= TUNNEL_ERSPAN_OPT;
}
return sizeof(struct erspan_metadata);
}
static int ip_tun_parse_opts(struct nlattr *attr, struct ip_tunnel_info *info,
struct netlink_ext_ack *extack)
{
int err, rem, opt_len, opts_len = 0;
struct nlattr *nla;
__be16 type = 0;
if (!attr)
return 0;
err = nla_validate(nla_data(attr), nla_len(attr), LWTUNNEL_IP_OPTS_MAX,
ip_opts_policy, extack);
if (err)
return err;
nla_for_each_attr(nla, nla_data(attr), nla_len(attr), rem) {
switch (nla_type(nla)) {
case LWTUNNEL_IP_OPTS_GENEVE:
if (type && type != TUNNEL_GENEVE_OPT)
return -EINVAL;
opt_len = ip_tun_parse_opts_geneve(nla, info, opts_len,
extack);
if (opt_len < 0)
return opt_len;
opts_len += opt_len;
if (opts_len > IP_TUNNEL_OPTS_MAX)
return -EINVAL;
type = TUNNEL_GENEVE_OPT;
break;
case LWTUNNEL_IP_OPTS_VXLAN:
if (type)
return -EINVAL;
opt_len = ip_tun_parse_opts_vxlan(nla, info, opts_len,
extack);
if (opt_len < 0)
return opt_len;
opts_len += opt_len;
type = TUNNEL_VXLAN_OPT;
break;
case LWTUNNEL_IP_OPTS_ERSPAN:
if (type)
return -EINVAL;
opt_len = ip_tun_parse_opts_erspan(nla, info, opts_len,
extack);
if (opt_len < 0)
return opt_len;
opts_len += opt_len;
type = TUNNEL_ERSPAN_OPT;
break;
default:
return -EINVAL;
}
}
return opts_len;
}
static int ip_tun_get_optlen(struct nlattr *attr,
struct netlink_ext_ack *extack)
{
return ip_tun_parse_opts(attr, NULL, extack);
}
static int ip_tun_set_opts(struct nlattr *attr, struct ip_tunnel_info *info,
struct netlink_ext_ack *extack)
{
return ip_tun_parse_opts(attr, info, extack);
}
static int ip_tun_build_state(struct net *net, struct nlattr *attr,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[LWTUNNEL_IP_MAX + 1];
struct lwtunnel_state *new_state;
struct ip_tunnel_info *tun_info;
int err, opt_len;
err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP_MAX, attr,
ip_tun_policy, extack);
if (err < 0)
return err;
opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP_OPTS], extack);
if (opt_len < 0)
return opt_len;
new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
if (!new_state)
return -ENOMEM;
new_state->type = LWTUNNEL_ENCAP_IP;
tun_info = lwt_tun_info(new_state);
err = ip_tun_set_opts(tb[LWTUNNEL_IP_OPTS], tun_info, extack);
if (err < 0) {
lwtstate_free(new_state);
return err;
}
#ifdef CONFIG_DST_CACHE
err = dst_cache_init(&tun_info->dst_cache, GFP_KERNEL);
if (err) {
lwtstate_free(new_state);
return err;
}
#endif
if (tb[LWTUNNEL_IP_ID])
tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP_ID]);
if (tb[LWTUNNEL_IP_DST])
tun_info->key.u.ipv4.dst = nla_get_in_addr(tb[LWTUNNEL_IP_DST]);
if (tb[LWTUNNEL_IP_SRC])
tun_info->key.u.ipv4.src = nla_get_in_addr(tb[LWTUNNEL_IP_SRC]);
if (tb[LWTUNNEL_IP_TTL])
tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP_TTL]);
if (tb[LWTUNNEL_IP_TOS])
tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP_TOS]);
if (tb[LWTUNNEL_IP_FLAGS])
tun_info->key.tun_flags |=
(nla_get_be16(tb[LWTUNNEL_IP_FLAGS]) &
~TUNNEL_OPTIONS_PRESENT);
tun_info->mode = IP_TUNNEL_INFO_TX;
tun_info->options_len = opt_len;
*ts = new_state;
return 0;
}
static void ip_tun_destroy_state(struct lwtunnel_state *lwtstate)
{
#ifdef CONFIG_DST_CACHE
struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
dst_cache_destroy(&tun_info->dst_cache);
#endif
}
static int ip_tun_fill_encap_opts_geneve(struct sk_buff *skb,
struct ip_tunnel_info *tun_info)
{
struct geneve_opt *opt;
struct nlattr *nest;
int offset = 0;
nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_GENEVE);
if (!nest)
return -ENOMEM;
while (tun_info->options_len > offset) {
opt = ip_tunnel_info_opts(tun_info) + offset;
if (nla_put_be16(skb, LWTUNNEL_IP_OPT_GENEVE_CLASS,
opt->opt_class) ||
nla_put_u8(skb, LWTUNNEL_IP_OPT_GENEVE_TYPE, opt->type) ||
nla_put(skb, LWTUNNEL_IP_OPT_GENEVE_DATA, opt->length * 4,
opt->opt_data)) {
nla_nest_cancel(skb, nest);
return -ENOMEM;
}
offset += sizeof(*opt) + opt->length * 4;
}
nla_nest_end(skb, nest);
return 0;
}
static int ip_tun_fill_encap_opts_vxlan(struct sk_buff *skb,
struct ip_tunnel_info *tun_info)
{
struct vxlan_metadata *md;
struct nlattr *nest;
nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_VXLAN);
if (!nest)
return -ENOMEM;
md = ip_tunnel_info_opts(tun_info);
if (nla_put_u32(skb, LWTUNNEL_IP_OPT_VXLAN_GBP, md->gbp)) {
nla_nest_cancel(skb, nest);
return -ENOMEM;
}
nla_nest_end(skb, nest);
return 0;
}
static int ip_tun_fill_encap_opts_erspan(struct sk_buff *skb,
struct ip_tunnel_info *tun_info)
{
struct erspan_metadata *md;
struct nlattr *nest;
nest = nla_nest_start_noflag(skb, LWTUNNEL_IP_OPTS_ERSPAN);
if (!nest)
return -ENOMEM;
md = ip_tunnel_info_opts(tun_info);
if (nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_VER, md->version))
goto err;
if (md->version == 1 &&
nla_put_be32(skb, LWTUNNEL_IP_OPT_ERSPAN_INDEX, md->u.index))
goto err;
if (md->version == 2 &&
(nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_DIR, md->u.md2.dir) ||
nla_put_u8(skb, LWTUNNEL_IP_OPT_ERSPAN_HWID,
get_hwid(&md->u.md2))))
goto err;
nla_nest_end(skb, nest);
return 0;
err:
nla_nest_cancel(skb, nest);
return -ENOMEM;
}
static int ip_tun_fill_encap_opts(struct sk_buff *skb, int type,
struct ip_tunnel_info *tun_info)
{
struct nlattr *nest;
int err = 0;
if (!(tun_info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
return 0;
nest = nla_nest_start_noflag(skb, type);
if (!nest)
return -ENOMEM;
if (tun_info->key.tun_flags & TUNNEL_GENEVE_OPT)
err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
else if (tun_info->key.tun_flags & TUNNEL_VXLAN_OPT)
err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
else if (tun_info->key.tun_flags & TUNNEL_ERSPAN_OPT)
err = ip_tun_fill_encap_opts_erspan(skb, tun_info);
if (err) {
nla_nest_cancel(skb, nest);
return err;
}
nla_nest_end(skb, nest);
return 0;
}
static int ip_tun_fill_encap_info(struct sk_buff *skb,
struct lwtunnel_state *lwtstate)
{
struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
if (nla_put_be64(skb, LWTUNNEL_IP_ID, tun_info->key.tun_id,
LWTUNNEL_IP_PAD) ||
nla_put_in_addr(skb, LWTUNNEL_IP_DST, tun_info->key.u.ipv4.dst) ||
nla_put_in_addr(skb, LWTUNNEL_IP_SRC, tun_info->key.u.ipv4.src) ||
nla_put_u8(skb, LWTUNNEL_IP_TOS, tun_info->key.tos) ||
nla_put_u8(skb, LWTUNNEL_IP_TTL, tun_info->key.ttl) ||
nla_put_be16(skb, LWTUNNEL_IP_FLAGS, tun_info->key.tun_flags) ||
ip_tun_fill_encap_opts(skb, LWTUNNEL_IP_OPTS, tun_info))
return -ENOMEM;
return 0;
}
static int ip_tun_opts_nlsize(struct ip_tunnel_info *info)
{
int opt_len;
if (!(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))
return 0;
opt_len = nla_total_size(0); /* LWTUNNEL_IP_OPTS */
if (info->key.tun_flags & TUNNEL_GENEVE_OPT) {
struct geneve_opt *opt;
int offset = 0;
opt_len += nla_total_size(0); /* LWTUNNEL_IP_OPTS_GENEVE */
while (info->options_len > offset) {
opt = ip_tunnel_info_opts(info) + offset;
opt_len += nla_total_size(2) /* OPT_GENEVE_CLASS */
+ nla_total_size(1) /* OPT_GENEVE_TYPE */
+ nla_total_size(opt->length * 4);
/* OPT_GENEVE_DATA */
offset += sizeof(*opt) + opt->length * 4;
}
} else if (info->key.tun_flags & TUNNEL_VXLAN_OPT) {
opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_VXLAN */
+ nla_total_size(4); /* OPT_VXLAN_GBP */
} else if (info->key.tun_flags & TUNNEL_ERSPAN_OPT) {
struct erspan_metadata *md = ip_tunnel_info_opts(info);
opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_ERSPAN */
+ nla_total_size(1) /* OPT_ERSPAN_VER */
+ (md->version == 1 ? nla_total_size(4)
/* OPT_ERSPAN_INDEX (v1) */
: nla_total_size(1) +
nla_total_size(1));
/* OPT_ERSPAN_DIR + HWID (v2) */
}
return opt_len;
}
static int ip_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
{
return nla_total_size_64bit(8) /* LWTUNNEL_IP_ID */
+ nla_total_size(4) /* LWTUNNEL_IP_DST */
+ nla_total_size(4) /* LWTUNNEL_IP_SRC */
+ nla_total_size(1) /* LWTUNNEL_IP_TOS */
+ nla_total_size(1) /* LWTUNNEL_IP_TTL */
+ nla_total_size(2) /* LWTUNNEL_IP_FLAGS */
+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
/* LWTUNNEL_IP_OPTS */
}
static int ip_tun_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b)
{
struct ip_tunnel_info *info_a = lwt_tun_info(a);
struct ip_tunnel_info *info_b = lwt_tun_info(b);
return memcmp(info_a, info_b, sizeof(info_a->key)) ||
info_a->mode != info_b->mode ||
info_a->options_len != info_b->options_len ||
memcmp(ip_tunnel_info_opts(info_a),
ip_tunnel_info_opts(info_b), info_a->options_len);
}
static const struct lwtunnel_encap_ops ip_tun_lwt_ops = {
.build_state = ip_tun_build_state,
.destroy_state = ip_tun_destroy_state,
.fill_encap = ip_tun_fill_encap_info,
.get_encap_size = ip_tun_encap_nlsize,
.cmp_encap = ip_tun_cmp_encap,
.owner = THIS_MODULE,
};
static const struct nla_policy ip6_tun_policy[LWTUNNEL_IP6_MAX + 1] = {
[LWTUNNEL_IP6_UNSPEC] = { .strict_start_type = LWTUNNEL_IP6_OPTS },
[LWTUNNEL_IP6_ID] = { .type = NLA_U64 },
[LWTUNNEL_IP6_DST] = { .len = sizeof(struct in6_addr) },
[LWTUNNEL_IP6_SRC] = { .len = sizeof(struct in6_addr) },
[LWTUNNEL_IP6_HOPLIMIT] = { .type = NLA_U8 },
[LWTUNNEL_IP6_TC] = { .type = NLA_U8 },
[LWTUNNEL_IP6_FLAGS] = { .type = NLA_U16 },
[LWTUNNEL_IP6_OPTS] = { .type = NLA_NESTED },
};
static int ip6_tun_build_state(struct net *net, struct nlattr *attr,
unsigned int family, const void *cfg,
struct lwtunnel_state **ts,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[LWTUNNEL_IP6_MAX + 1];
struct lwtunnel_state *new_state;
struct ip_tunnel_info *tun_info;
int err, opt_len;
err = nla_parse_nested_deprecated(tb, LWTUNNEL_IP6_MAX, attr,
ip6_tun_policy, extack);
if (err < 0)
return err;
opt_len = ip_tun_get_optlen(tb[LWTUNNEL_IP6_OPTS], extack);
if (opt_len < 0)
return opt_len;
new_state = lwtunnel_state_alloc(sizeof(*tun_info) + opt_len);
if (!new_state)
return -ENOMEM;
new_state->type = LWTUNNEL_ENCAP_IP6;
tun_info = lwt_tun_info(new_state);
err = ip_tun_set_opts(tb[LWTUNNEL_IP6_OPTS], tun_info, extack);
if (err < 0) {
lwtstate_free(new_state);
return err;
}
if (tb[LWTUNNEL_IP6_ID])
tun_info->key.tun_id = nla_get_be64(tb[LWTUNNEL_IP6_ID]);
if (tb[LWTUNNEL_IP6_DST])
tun_info->key.u.ipv6.dst = nla_get_in6_addr(tb[LWTUNNEL_IP6_DST]);
if (tb[LWTUNNEL_IP6_SRC])
tun_info->key.u.ipv6.src = nla_get_in6_addr(tb[LWTUNNEL_IP6_SRC]);
if (tb[LWTUNNEL_IP6_HOPLIMIT])
tun_info->key.ttl = nla_get_u8(tb[LWTUNNEL_IP6_HOPLIMIT]);
if (tb[LWTUNNEL_IP6_TC])
tun_info->key.tos = nla_get_u8(tb[LWTUNNEL_IP6_TC]);
if (tb[LWTUNNEL_IP6_FLAGS])
tun_info->key.tun_flags |=
(nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]) &
~TUNNEL_OPTIONS_PRESENT);
tun_info->mode = IP_TUNNEL_INFO_TX | IP_TUNNEL_INFO_IPV6;
tun_info->options_len = opt_len;
*ts = new_state;
return 0;
}
static int ip6_tun_fill_encap_info(struct sk_buff *skb,
struct lwtunnel_state *lwtstate)
{
struct ip_tunnel_info *tun_info = lwt_tun_info(lwtstate);
if (nla_put_be64(skb, LWTUNNEL_IP6_ID, tun_info->key.tun_id,
LWTUNNEL_IP6_PAD) ||
nla_put_in6_addr(skb, LWTUNNEL_IP6_DST, &tun_info->key.u.ipv6.dst) ||
nla_put_in6_addr(skb, LWTUNNEL_IP6_SRC, &tun_info->key.u.ipv6.src) ||
nla_put_u8(skb, LWTUNNEL_IP6_TC, tun_info->key.tos) ||
nla_put_u8(skb, LWTUNNEL_IP6_HOPLIMIT, tun_info->key.ttl) ||
nla_put_be16(skb, LWTUNNEL_IP6_FLAGS, tun_info->key.tun_flags) ||
ip_tun_fill_encap_opts(skb, LWTUNNEL_IP6_OPTS, tun_info))
return -ENOMEM;
return 0;
}
static int ip6_tun_encap_nlsize(struct lwtunnel_state *lwtstate)
{
return nla_total_size_64bit(8) /* LWTUNNEL_IP6_ID */
+ nla_total_size(16) /* LWTUNNEL_IP6_DST */
+ nla_total_size(16) /* LWTUNNEL_IP6_SRC */
+ nla_total_size(1) /* LWTUNNEL_IP6_HOPLIMIT */
+ nla_total_size(1) /* LWTUNNEL_IP6_TC */
+ nla_total_size(2) /* LWTUNNEL_IP6_FLAGS */
+ ip_tun_opts_nlsize(lwt_tun_info(lwtstate));
/* LWTUNNEL_IP6_OPTS */
}
static const struct lwtunnel_encap_ops ip6_tun_lwt_ops = {
.build_state = ip6_tun_build_state,
.fill_encap = ip6_tun_fill_encap_info,
.get_encap_size = ip6_tun_encap_nlsize,
.cmp_encap = ip_tun_cmp_encap,
.owner = THIS_MODULE,
};
void __init ip_tunnel_core_init(void)
{
/* If you land here, make sure whether increasing ip_tunnel_info's
* options_len is a reasonable choice with its usage in front ends
* (f.e., it's part of flow keys, etc).
*/
BUILD_BUG_ON(IP_TUNNEL_OPTS_MAX != 255);
lwtunnel_encap_add_ops(&ip_tun_lwt_ops, LWTUNNEL_ENCAP_IP);
lwtunnel_encap_add_ops(&ip6_tun_lwt_ops, LWTUNNEL_ENCAP_IP6);
}
DEFINE_STATIC_KEY_FALSE(ip_tunnel_metadata_cnt);
EXPORT_SYMBOL(ip_tunnel_metadata_cnt);
void ip_tunnel_need_metadata(void)
{
static_branch_inc(&ip_tunnel_metadata_cnt);
}
EXPORT_SYMBOL_GPL(ip_tunnel_need_metadata);
void ip_tunnel_unneed_metadata(void)
{
static_branch_dec(&ip_tunnel_metadata_cnt);
}
EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
/* Returns either the correct skb->protocol value, or 0 if invalid. */
__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
{
if (skb_network_header(skb) >= skb->head &&
(skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
ip_hdr(skb)->version == 4)
return htons(ETH_P_IP);
if (skb_network_header(skb) >= skb->head &&
(skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
ipv6_hdr(skb)->version == 6)
return htons(ETH_P_IPV6);
return 0;
}
EXPORT_SYMBOL(ip_tunnel_parse_protocol);
const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
EXPORT_SYMBOL(ip_tunnel_header_ops);