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linux/net/ipv4/ip_tunnel_core.c
Alexander Lobakin 5832c4a77d ip_tunnel: convert __be16 tunnel flags to bitmaps 
Historically, tunnel flags like TUNNEL_CSUM or TUNNEL_ERSPAN_OPT
have been defined as __be16. Now all of those 16 bits are occupied
and there's no more free space for new flags.
It can't be simply switched to a bigger container with no
adjustments to the values, since it's an explicit Endian storage,
and on LE systems (__be16)0x0001 equals to
(__be64)0x0001000000000000.
We could probably define new 64-bit flags depending on the
Endianness, i.e. (__be64)0x0001 on BE and (__be64)0x00010000... on
LE, but that would introduce an Endianness dependency and spawn a
ton of Sparse warnings. To mitigate them, all of those places which
were adjusted with this change would be touched anyway, so why not
define stuff properly if there's no choice.

Define IP_TUNNEL_*_BIT counterparts as a bit number instead of the
value already coded and a fistful of <16 <-> bitmap> converters and
helpers. The two flags which have a different bit position are
SIT_ISATAP_BIT and VTI_ISVTI_BIT, as they were defined not as
__cpu_to_be16(), but as (__force __be16), i.e. had different
positions on LE and BE. Now they both have strongly defined places.
Change all __be16 fields which were used to store those flags, to
IP_TUNNEL_DECLARE_FLAGS() -> DECLARE_BITMAP(__IP_TUNNEL_FLAG_NUM) ->
unsigned long[1] for now, and replace all TUNNEL_* occurrences to
their bitmap counterparts. Use the converters in the places which talk
to the userspace, hardware (NFP) or other hosts (GRE header). The rest
must explicitly use the new flags only. This must be done at once,
otherwise there will be too many conversions throughout the code in
the intermediate commits.
Finally, disable the old __be16 flags for use in the kernel code
(except for the two 'irregular' flags mentioned above), to prevent
any accidental (mis)use of them. For the userspace, nothing is
changed, only additions were made.

Most noticeable bloat-o-meter difference (.text):

vmlinux:	307/-1 (306)
gre.ko:		62/0 (62)
ip_gre.ko:	941/-217 (724)	[*]
ip_tunnel.ko:	390/-900 (-510)	[**]
ip_vti.ko:	138/0 (138)
ip6_gre.ko:	534/-18 (516)	[*]
ip6_tunnel.ko:	118/-10 (108)

[*] gre_flags_to_tnl_flags() grew, but still is inlined
[**] ip_tunnel_find() got uninlined, hence such decrease

The average code size increase in non-extreme case is 100-200 bytes
per module, mostly due to sizeof(long) > sizeof(__be16), as
%__IP_TUNNEL_FLAG_NUM is less than %BITS_PER_LONG and the compilers
are able to expand the majority of bitmap_*() calls here into direct
operations on scalars.

Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-04-01 10:49:28 +01:00

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// 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)
{
IP_TUNNEL_DECLARE_FLAGS(tun_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;
ip_tunnel_flags_copy(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, tun_flags);
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 = csum_fold(skb_checksum(skb, 0, len, 0));
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 = skb_checksum(skb, skb_transport_offset(skb), 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);
__set_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags);
}
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;
__set_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags);
}
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));
}
__set_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags);
}
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;
u32 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 != IP_TUNNEL_GENEVE_OPT_BIT)
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 = IP_TUNNEL_GENEVE_OPT_BIT;
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 = IP_TUNNEL_VXLAN_OPT_BIT;
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 = IP_TUNNEL_ERSPAN_OPT_BIT;
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]) {
IP_TUNNEL_DECLARE_FLAGS(flags);
ip_tunnel_flags_from_be16(flags,
nla_get_be16(tb[LWTUNNEL_IP_FLAGS]));
ip_tunnel_clear_options_present(flags);
ip_tunnel_flags_or(tun_info->key.tun_flags,
tun_info->key.tun_flags, flags);
}
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 (!ip_tunnel_is_options_present(tun_info->key.tun_flags))
return 0;
nest = nla_nest_start_noflag(skb, type);
if (!nest)
return -ENOMEM;
if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, tun_info->key.tun_flags))
err = ip_tun_fill_encap_opts_geneve(skb, tun_info);
else if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, tun_info->key.tun_flags))
err = ip_tun_fill_encap_opts_vxlan(skb, tun_info);
else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, tun_info->key.tun_flags))
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,
ip_tunnel_flags_to_be16(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 (!ip_tunnel_is_options_present(info->key.tun_flags))
return 0;
opt_len = nla_total_size(0); /* LWTUNNEL_IP_OPTS */
if (test_bit(IP_TUNNEL_GENEVE_OPT_BIT, info->key.tun_flags)) {
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 (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) {
opt_len += nla_total_size(0) /* LWTUNNEL_IP_OPTS_VXLAN */
+ nla_total_size(4); /* OPT_VXLAN_GBP */
} else if (test_bit(IP_TUNNEL_ERSPAN_OPT_BIT, info->key.tun_flags)) {
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]) {
IP_TUNNEL_DECLARE_FLAGS(flags);
__be16 data;
data = nla_get_be16(tb[LWTUNNEL_IP6_FLAGS]);
ip_tunnel_flags_from_be16(flags, data);
ip_tunnel_clear_options_present(flags);
ip_tunnel_flags_or(tun_info->key.tun_flags,
tun_info->key.tun_flags, flags);
}
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,
ip_tunnel_flags_to_be16(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);
/* This function returns true when ENCAP attributes are present in the nl msg */
bool ip_tunnel_netlink_encap_parms(struct nlattr *data[],
struct ip_tunnel_encap *encap)
{
bool ret = false;
memset(encap, 0, sizeof(*encap));
if (!data)
return ret;
if (data[IFLA_IPTUN_ENCAP_TYPE]) {
ret = true;
encap->type = nla_get_u16(data[IFLA_IPTUN_ENCAP_TYPE]);
}
if (data[IFLA_IPTUN_ENCAP_FLAGS]) {
ret = true;
encap->flags = nla_get_u16(data[IFLA_IPTUN_ENCAP_FLAGS]);
}
if (data[IFLA_IPTUN_ENCAP_SPORT]) {
ret = true;
encap->sport = nla_get_be16(data[IFLA_IPTUN_ENCAP_SPORT]);
}
if (data[IFLA_IPTUN_ENCAP_DPORT]) {
ret = true;
encap->dport = nla_get_be16(data[IFLA_IPTUN_ENCAP_DPORT]);
}
return ret;
}
EXPORT_SYMBOL_GPL(ip_tunnel_netlink_encap_parms);
void ip_tunnel_netlink_parms(struct nlattr *data[],
struct ip_tunnel_parm_kern *parms)
{
if (data[IFLA_IPTUN_LINK])
parms->link = nla_get_u32(data[IFLA_IPTUN_LINK]);
if (data[IFLA_IPTUN_LOCAL])
parms->iph.saddr = nla_get_be32(data[IFLA_IPTUN_LOCAL]);
if (data[IFLA_IPTUN_REMOTE])
parms->iph.daddr = nla_get_be32(data[IFLA_IPTUN_REMOTE]);
if (data[IFLA_IPTUN_TTL]) {
parms->iph.ttl = nla_get_u8(data[IFLA_IPTUN_TTL]);
if (parms->iph.ttl)
parms->iph.frag_off = htons(IP_DF);
}
if (data[IFLA_IPTUN_TOS])
parms->iph.tos = nla_get_u8(data[IFLA_IPTUN_TOS]);
if (!data[IFLA_IPTUN_PMTUDISC] || nla_get_u8(data[IFLA_IPTUN_PMTUDISC]))
parms->iph.frag_off = htons(IP_DF);
if (data[IFLA_IPTUN_FLAGS]) {
__be16 flags;
flags = nla_get_be16(data[IFLA_IPTUN_FLAGS]);
ip_tunnel_flags_from_be16(parms->i_flags, flags);
}
if (data[IFLA_IPTUN_PROTO])
parms->iph.protocol = nla_get_u8(data[IFLA_IPTUN_PROTO]);
}
EXPORT_SYMBOL_GPL(ip_tunnel_netlink_parms);
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