// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/icmp.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/genetlink.h>
#include <net/gro.h>
#include <net/gue.h>
#include <net/fou.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <uapi/linux/fou.h>
#include <uapi/linux/genetlink.h>
#include "fou_nl.h"
struct fou {
struct socket *sock;
u8 protocol;
u8 flags;
__be16 port;
u8 family;
u16 type;
struct list_head list;
struct rcu_head rcu;
};
#define FOU_F_REMCSUM_NOPARTIAL BIT(0)
struct fou_cfg {
u16 type;
u8 protocol;
u8 flags;
struct udp_port_cfg udp_config;
};
static unsigned int fou_net_id;
struct fou_net {
struct list_head fou_list;
struct mutex fou_lock;
};
static inline struct fou *fou_from_sock(struct sock *sk)
{
return rcu_dereference_sk_user_data(sk);
}
static int fou_recv_pull(struct sk_buff *skb, struct fou *fou, size_t len)
{
/* Remove 'len' bytes from the packet (UDP header and
* FOU header if present).
*/
if (fou->family == AF_INET)
ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
else
ipv6_hdr(skb)->payload_len =
htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
__skb_pull(skb, len);
skb_postpull_rcsum(skb, udp_hdr(skb), len);
skb_reset_transport_header(skb);
return iptunnel_pull_offloads(skb);
}
static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct fou *fou = fou_from_sock(sk);
if (!fou)
return 1;
if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
goto drop;
return -fou->protocol;
drop:
kfree_skb(skb);
return 0;
}
static struct guehdr *gue_remcsum(struct sk_buff *skb, struct guehdr *guehdr,
void *data, size_t hdrlen, u8 ipproto,
bool nopartial)
{
__be16 *pd = data;
size_t start = ntohs(pd[0]);
size_t offset = ntohs(pd[1]);
size_t plen = sizeof(struct udphdr) + hdrlen +
max_t(size_t, offset + sizeof(u16), start);
if (skb->remcsum_offload)
return guehdr;
if (!pskb_may_pull(skb, plen))
return NULL;
guehdr = (struct guehdr *)&udp_hdr(skb)[1];
skb_remcsum_process(skb, (void *)guehdr + hdrlen,
start, offset, nopartial);
return guehdr;
}
static int gue_control_message(struct sk_buff *skb, struct guehdr *guehdr)
{
/* No support yet */
kfree_skb(skb);
return 0;
}
static int gue_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct fou *fou = fou_from_sock(sk);
size_t len, optlen, hdrlen;
struct guehdr *guehdr;
void *data;
u16 doffset = 0;
u8 proto_ctype;
if (!fou)
return 1;
len = sizeof(struct udphdr) + sizeof(struct guehdr);
if (!pskb_may_pull(skb, len))
goto drop;
guehdr = (struct guehdr *)&udp_hdr(skb)[1];
switch (guehdr->version) {
case 0: /* Full GUE header present */
break;
case 1: {
/* Direct encapsulation of IPv4 or IPv6 */
int prot;
switch (((struct iphdr *)guehdr)->version) {
case 4:
prot = IPPROTO_IPIP;
break;
case 6:
prot = IPPROTO_IPV6;
break;
default:
goto drop;
}
if (fou_recv_pull(skb, fou, sizeof(struct udphdr)))
goto drop;
return -prot;
}
default: /* Undefined version */
goto drop;
}
optlen = guehdr->hlen << 2;
len += optlen;
if (!pskb_may_pull(skb, len))
goto drop;
/* guehdr may change after pull */
guehdr = (struct guehdr *)&udp_hdr(skb)[1];
if (validate_gue_flags(guehdr, optlen))
goto drop;
hdrlen = sizeof(struct guehdr) + optlen;
if (fou->family == AF_INET)
ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_len) - len);
else
ipv6_hdr(skb)->payload_len =
htons(ntohs(ipv6_hdr(skb)->payload_len) - len);
/* Pull csum through the guehdr now . This can be used if
* there is a remote checksum offload.
*/
skb_postpull_rcsum(skb, udp_hdr(skb), len);
data = &guehdr[1];
if (guehdr->flags & GUE_FLAG_PRIV) {
__be32 flags = *(__be32 *)(data + doffset);
doffset += GUE_LEN_PRIV;
if (flags & GUE_PFLAG_REMCSUM) {
guehdr = gue_remcsum(skb, guehdr, data + doffset,
hdrlen, guehdr->proto_ctype,
!!(fou->flags &
FOU_F_REMCSUM_NOPARTIAL));
if (!guehdr)
goto drop;
data = &guehdr[1];
doffset += GUE_PLEN_REMCSUM;
}
}
if (unlikely(guehdr->control))
return gue_control_message(skb, guehdr);
proto_ctype = guehdr->proto_ctype;
__skb_pull(skb, sizeof(struct udphdr) + hdrlen);
skb_reset_transport_header(skb);
if (iptunnel_pull_offloads(skb))
goto drop;
return -proto_ctype;
drop:
kfree_skb(skb);
return 0;
}
static struct sk_buff *fou_gro_receive(struct sock *sk,
struct list_head *head,
struct sk_buff *skb)
{
const struct net_offload __rcu **offloads;
struct fou *fou = fou_from_sock(sk);
const struct net_offload *ops;
struct sk_buff *pp = NULL;
u8 proto;
if (!fou)
goto out;
proto = fou->protocol;
/* We can clear the encap_mark for FOU as we are essentially doing
* one of two possible things. We are either adding an L4 tunnel
* header to the outer L3 tunnel header, or we are simply
* treating the GRE tunnel header as though it is a UDP protocol
* specific header such as VXLAN or GENEVE.
*/
NAPI_GRO_CB(skb)->encap_mark = 0;
/* Flag this frame as already having an outer encap header */
NAPI_GRO_CB(skb)->is_fou = 1;
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (!ops || !ops->callbacks.gro_receive)
goto out;
pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
out:
return pp;
}
static int fou_gro_complete(struct sock *sk, struct sk_buff *skb,
int nhoff)
{
const struct net_offload __rcu **offloads;
struct fou *fou = fou_from_sock(sk);
const struct net_offload *ops;
u8 proto;
int err;
if (!fou) {
err = -ENOENT;
goto out;
}
proto = fou->protocol;
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (WARN_ON(!ops || !ops->callbacks.gro_complete)) {
err = -ENOSYS;
goto out;
}
err = ops->callbacks.gro_complete(skb, nhoff);
skb_set_inner_mac_header(skb, nhoff);
out:
return err;
}
static struct guehdr *gue_gro_remcsum(struct sk_buff *skb, unsigned int off,
struct guehdr *guehdr, void *data,
size_t hdrlen, struct gro_remcsum *grc,
bool nopartial)
{
__be16 *pd = data;
size_t start = ntohs(pd[0]);
size_t offset = ntohs(pd[1]);
if (skb->remcsum_offload)
return guehdr;
if (!NAPI_GRO_CB(skb)->csum_valid)
return NULL;
guehdr = skb_gro_remcsum_process(skb, (void *)guehdr, off, hdrlen,
start, offset, grc, nopartial);
skb->remcsum_offload = 1;
return guehdr;
}
static struct sk_buff *gue_gro_receive(struct sock *sk,
struct list_head *head,
struct sk_buff *skb)
{
const struct net_offload __rcu **offloads;
const struct net_offload *ops;
struct sk_buff *pp = NULL;
struct sk_buff *p;
struct guehdr *guehdr;
size_t len, optlen, hdrlen, off;
void *data;
u16 doffset = 0;
int flush = 1;
struct fou *fou = fou_from_sock(sk);
struct gro_remcsum grc;
u8 proto;
skb_gro_remcsum_init(&grc);
if (!fou)
goto out;
off = skb_gro_offset(skb);
len = off + sizeof(*guehdr);
guehdr = skb_gro_header(skb, len, off);
if (unlikely(!guehdr))
goto out;
switch (guehdr->version) {
case 0:
break;
case 1:
switch (((struct iphdr *)guehdr)->version) {
case 4:
proto = IPPROTO_IPIP;
break;
case 6:
proto = IPPROTO_IPV6;
break;
default:
goto out;
}
goto next_proto;
default:
goto out;
}
optlen = guehdr->hlen << 2;
len += optlen;
if (!skb_gro_may_pull(skb, len)) {
guehdr = skb_gro_header_slow(skb, len, off);
if (unlikely(!guehdr))
goto out;
}
if (unlikely(guehdr->control) || guehdr->version != 0 ||
validate_gue_flags(guehdr, optlen))
goto out;
hdrlen = sizeof(*guehdr) + optlen;
/* Adjust NAPI_GRO_CB(skb)->csum to account for guehdr,
* this is needed if there is a remote checkcsum offload.
*/
skb_gro_postpull_rcsum(skb, guehdr, hdrlen);
data = &guehdr[1];
if (guehdr->flags & GUE_FLAG_PRIV) {
__be32 flags = *(__be32 *)(data + doffset);
doffset += GUE_LEN_PRIV;
if (flags & GUE_PFLAG_REMCSUM) {
guehdr = gue_gro_remcsum(skb, off, guehdr,
data + doffset, hdrlen, &grc,
!!(fou->flags &
FOU_F_REMCSUM_NOPARTIAL));
if (!guehdr)
goto out;
data = &guehdr[1];
doffset += GUE_PLEN_REMCSUM;
}
}
skb_gro_pull(skb, hdrlen);
list_for_each_entry(p, head, list) {
const struct guehdr *guehdr2;
if (!NAPI_GRO_CB(p)->same_flow)
continue;
guehdr2 = (struct guehdr *)(p->data + off);
/* Compare base GUE header to be equal (covers
* hlen, version, proto_ctype, and flags.
*/
if (guehdr->word != guehdr2->word) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
/* Compare optional fields are the same. */
if (guehdr->hlen && memcmp(&guehdr[1], &guehdr2[1],
guehdr->hlen << 2)) {
NAPI_GRO_CB(p)->same_flow = 0;
continue;
}
}
proto = guehdr->proto_ctype;
next_proto:
/* We can clear the encap_mark for GUE as we are essentially doing
* one of two possible things. We are either adding an L4 tunnel
* header to the outer L3 tunnel header, or we are simply
* treating the GRE tunnel header as though it is a UDP protocol
* specific header such as VXLAN or GENEVE.
*/
NAPI_GRO_CB(skb)->encap_mark = 0;
/* Flag this frame as already having an outer encap header */
NAPI_GRO_CB(skb)->is_fou = 1;
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (!ops || !ops->callbacks.gro_receive)
goto out;
pp = call_gro_receive(ops->callbacks.gro_receive, head, skb);
flush = 0;
out:
skb_gro_flush_final_remcsum(skb, pp, flush, &grc);
return pp;
}
static int gue_gro_complete(struct sock *sk, struct sk_buff *skb, int nhoff)
{
struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
const struct net_offload __rcu **offloads;
const struct net_offload *ops;
unsigned int guehlen = 0;
u8 proto;
int err = -ENOENT;
switch (guehdr->version) {
case 0:
proto = guehdr->proto_ctype;
guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
break;
case 1:
switch (((struct iphdr *)guehdr)->version) {
case 4:
proto = IPPROTO_IPIP;
break;
case 6:
proto = IPPROTO_IPV6;
break;
default:
return err;
}
break;
default:
return err;
}
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (WARN_ON(!ops || !ops->callbacks.gro_complete))
goto out;
err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
skb_set_inner_mac_header(skb, nhoff + guehlen);
out:
return err;
}
static bool fou_cfg_cmp(struct fou *fou, struct fou_cfg *cfg)
{
struct sock *sk = fou->sock->sk;
struct udp_port_cfg *udp_cfg = &cfg->udp_config;
if (fou->family != udp_cfg->family ||
fou->port != udp_cfg->local_udp_port ||
sk->sk_dport != udp_cfg->peer_udp_port ||
sk->sk_bound_dev_if != udp_cfg->bind_ifindex)
return false;
if (fou->family == AF_INET) {
if (sk->sk_rcv_saddr != udp_cfg->local_ip.s_addr ||
sk->sk_daddr != udp_cfg->peer_ip.s_addr)
return false;
else
return true;
#if IS_ENABLED(CONFIG_IPV6)
} else {
if (ipv6_addr_cmp(&sk->sk_v6_rcv_saddr, &udp_cfg->local_ip6) ||
ipv6_addr_cmp(&sk->sk_v6_daddr, &udp_cfg->peer_ip6))
return false;
else
return true;
#endif
}
return false;
}
static int fou_add_to_port_list(struct net *net, struct fou *fou,
struct fou_cfg *cfg)
{
struct fou_net *fn = net_generic(net, fou_net_id);
struct fou *fout;
mutex_lock(&fn->fou_lock);
list_for_each_entry(fout, &fn->fou_list, list) {
if (fou_cfg_cmp(fout, cfg)) {
mutex_unlock(&fn->fou_lock);
return -EALREADY;
}
}
list_add(&fou->list, &fn->fou_list);
mutex_unlock(&fn->fou_lock);
return 0;
}
static void fou_release(struct fou *fou)
{
struct socket *sock = fou->sock;
list_del(&fou->list);
udp_tunnel_sock_release(sock);
kfree_rcu(fou, rcu);
}
static int fou_create(struct net *net, struct fou_cfg *cfg,
struct socket **sockp)
{
struct socket *sock = NULL;
struct fou *fou = NULL;
struct sock *sk;
struct udp_tunnel_sock_cfg tunnel_cfg;
int err;
/* Open UDP socket */
err = udp_sock_create(net, &cfg->udp_config, &sock);
if (err < 0)
goto error;
/* Allocate FOU port structure */
fou = kzalloc(sizeof(*fou), GFP_KERNEL);
if (!fou) {
err = -ENOMEM;
goto error;
}
sk = sock->sk;
fou->port = cfg->udp_config.local_udp_port;
fou->family = cfg->udp_config.family;
fou->flags = cfg->flags;
fou->type = cfg->type;
fou->sock = sock;
memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
tunnel_cfg.encap_type = 1;
tunnel_cfg.sk_user_data = fou;
tunnel_cfg.encap_destroy = NULL;
/* Initial for fou type */
switch (cfg->type) {
case FOU_ENCAP_DIRECT:
tunnel_cfg.encap_rcv = fou_udp_recv;
tunnel_cfg.gro_receive = fou_gro_receive;
tunnel_cfg.gro_complete = fou_gro_complete;
fou->protocol = cfg->protocol;
break;
case FOU_ENCAP_GUE:
tunnel_cfg.encap_rcv = gue_udp_recv;
tunnel_cfg.gro_receive = gue_gro_receive;
tunnel_cfg.gro_complete = gue_gro_complete;
break;
default:
err = -EINVAL;
goto error;
}
setup_udp_tunnel_sock(net, sock, &tunnel_cfg);
sk->sk_allocation = GFP_ATOMIC;
err = fou_add_to_port_list(net, fou, cfg);
if (err)
goto error;
if (sockp)
*sockp = sock;
return 0;
error:
kfree(fou);
if (sock)
udp_tunnel_sock_release(sock);
return err;
}
static int fou_destroy(struct net *net, struct fou_cfg *cfg)
{
struct fou_net *fn = net_generic(net, fou_net_id);
int err = -EINVAL;
struct fou *fou;
mutex_lock(&fn->fou_lock);
list_for_each_entry(fou, &fn->fou_list, list) {
if (fou_cfg_cmp(fou, cfg)) {
fou_release(fou);
err = 0;
break;
}
}
mutex_unlock(&fn->fou_lock);
return err;
}
static struct genl_family fou_nl_family;
static int parse_nl_config(struct genl_info *info,
struct fou_cfg *cfg)
{
bool has_local = false, has_peer = false;
struct nlattr *attr;
int ifindex;
__be16 port;
memset(cfg, 0, sizeof(*cfg));
cfg->udp_config.family = AF_INET;
if (info->attrs[FOU_ATTR_AF]) {
u8 family = nla_get_u8(info->attrs[FOU_ATTR_AF]);
switch (family) {
case AF_INET:
break;
case AF_INET6:
cfg->udp_config.ipv6_v6only = 1;
break;
default:
return -EAFNOSUPPORT;
}
cfg->udp_config.family = family;
}
if (info->attrs[FOU_ATTR_PORT]) {
port = nla_get_be16(info->attrs[FOU_ATTR_PORT]);
cfg->udp_config.local_udp_port = port;
}
if (info->attrs[FOU_ATTR_IPPROTO])
cfg->protocol = nla_get_u8(info->attrs[FOU_ATTR_IPPROTO]);
if (info->attrs[FOU_ATTR_TYPE])
cfg->type = nla_get_u8(info->attrs[FOU_ATTR_TYPE]);
if (info->attrs[FOU_ATTR_REMCSUM_NOPARTIAL])
cfg->flags |= FOU_F_REMCSUM_NOPARTIAL;
if (cfg->udp_config.family == AF_INET) {
if (info->attrs[FOU_ATTR_LOCAL_V4]) {
attr = info->attrs[FOU_ATTR_LOCAL_V4];
cfg->udp_config.local_ip.s_addr = nla_get_in_addr(attr);
has_local = true;
}
if (info->attrs[FOU_ATTR_PEER_V4]) {
attr = info->attrs[FOU_ATTR_PEER_V4];
cfg->udp_config.peer_ip.s_addr = nla_get_in_addr(attr);
has_peer = true;
}
#if IS_ENABLED(CONFIG_IPV6)
} else {
if (info->attrs[FOU_ATTR_LOCAL_V6]) {
attr = info->attrs[FOU_ATTR_LOCAL_V6];
cfg->udp_config.local_ip6 = nla_get_in6_addr(attr);
has_local = true;
}
if (info->attrs[FOU_ATTR_PEER_V6]) {
attr = info->attrs[FOU_ATTR_PEER_V6];
cfg->udp_config.peer_ip6 = nla_get_in6_addr(attr);
has_peer = true;
}
#endif
}
if (has_peer) {
if (info->attrs[FOU_ATTR_PEER_PORT]) {
port = nla_get_be16(info->attrs[FOU_ATTR_PEER_PORT]);
cfg->udp_config.peer_udp_port = port;
} else {
return -EINVAL;
}
}
if (info->attrs[FOU_ATTR_IFINDEX]) {
if (!has_local)
return -EINVAL;
ifindex = nla_get_s32(info->attrs[FOU_ATTR_IFINDEX]);
cfg->udp_config.bind_ifindex = ifindex;
}
return 0;
}
int fou_nl_add_doit(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
struct fou_cfg cfg;
int err;
err = parse_nl_config(info, &cfg);
if (err)
return err;
return fou_create(net, &cfg, NULL);
}
int fou_nl_del_doit(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
struct fou_cfg cfg;
int err;
err = parse_nl_config(info, &cfg);
if (err)
return err;
return fou_destroy(net, &cfg);
}
static int fou_fill_info(struct fou *fou, struct sk_buff *msg)
{
struct sock *sk = fou->sock->sk;
if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
nla_put_be16(msg, FOU_ATTR_PEER_PORT, sk->sk_dport) ||
nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
nla_put_u8(msg, FOU_ATTR_TYPE, fou->type) ||
nla_put_s32(msg, FOU_ATTR_IFINDEX, sk->sk_bound_dev_if))
return -1;
if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
return -1;
if (fou->sock->sk->sk_family == AF_INET) {
if (nla_put_in_addr(msg, FOU_ATTR_LOCAL_V4, sk->sk_rcv_saddr))
return -1;
if (nla_put_in_addr(msg, FOU_ATTR_PEER_V4, sk->sk_daddr))
return -1;
#if IS_ENABLED(CONFIG_IPV6)
} else {
if (nla_put_in6_addr(msg, FOU_ATTR_LOCAL_V6,
&sk->sk_v6_rcv_saddr))
return -1;
if (nla_put_in6_addr(msg, FOU_ATTR_PEER_V6, &sk->sk_v6_daddr))
return -1;
#endif
}
return 0;
}
static int fou_dump_info(struct fou *fou, u32 portid, u32 seq,
u32 flags, struct sk_buff *skb, u8 cmd)
{
void *hdr;
hdr = genlmsg_put(skb, portid, seq, &fou_nl_family, flags, cmd);
if (!hdr)
return -ENOMEM;
if (fou_fill_info(fou, skb) < 0)
goto nla_put_failure;
genlmsg_end(skb, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -EMSGSIZE;
}
int fou_nl_get_doit(struct sk_buff *skb, struct genl_info *info)
{
struct net *net = genl_info_net(info);
struct fou_net *fn = net_generic(net, fou_net_id);
struct sk_buff *msg;
struct fou_cfg cfg;
struct fou *fout;
__be16 port;
u8 family;
int ret;
ret = parse_nl_config(info, &cfg);
if (ret)
return ret;
port = cfg.udp_config.local_udp_port;
if (port == 0)
return -EINVAL;
family = cfg.udp_config.family;
if (family != AF_INET && family != AF_INET6)
return -EINVAL;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
if (!msg)
return -ENOMEM;
ret = -ESRCH;
mutex_lock(&fn->fou_lock);
list_for_each_entry(fout, &fn->fou_list, list) {
if (fou_cfg_cmp(fout, &cfg)) {
ret = fou_dump_info(fout, info->snd_portid,
info->snd_seq, 0, msg,
info->genlhdr->cmd);
break;
}
}
mutex_unlock(&fn->fou_lock);
if (ret < 0)
goto out_free;
return genlmsg_reply(msg, info);
out_free:
nlmsg_free(msg);
return ret;
}
int fou_nl_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
{
struct net *net = sock_net(skb->sk);
struct fou_net *fn = net_generic(net, fou_net_id);
struct fou *fout;
int idx = 0, ret;
mutex_lock(&fn->fou_lock);
list_for_each_entry(fout, &fn->fou_list, list) {
if (idx++ < cb->args[0])
continue;
ret = fou_dump_info(fout, NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
skb, FOU_CMD_GET);
if (ret)
break;
}
mutex_unlock(&fn->fou_lock);
cb->args[0] = idx;
return skb->len;
}
static struct genl_family fou_nl_family __ro_after_init = {
.hdrsize = 0,
.name = FOU_GENL_NAME,
.version = FOU_GENL_VERSION,
.maxattr = FOU_ATTR_MAX,
.policy = fou_nl_policy,
.netnsok = true,
.module = THIS_MODULE,
.small_ops = fou_nl_ops,
.n_small_ops = ARRAY_SIZE(fou_nl_ops),
.resv_start_op = FOU_CMD_GET + 1,
};
size_t fou_encap_hlen(struct ip_tunnel_encap *e)
{
return sizeof(struct udphdr);
}
EXPORT_SYMBOL(fou_encap_hlen);
size_t gue_encap_hlen(struct ip_tunnel_encap *e)
{
size_t len;
bool need_priv = false;
len = sizeof(struct udphdr) + sizeof(struct guehdr);
if (e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) {
len += GUE_PLEN_REMCSUM;
need_priv = true;
}
len += need_priv ? GUE_LEN_PRIV : 0;
return len;
}
EXPORT_SYMBOL(gue_encap_hlen);
int __fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, __be16 *sport, int type)
{
int err;
err = iptunnel_handle_offloads(skb, type);
if (err)
return err;
*sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
return 0;
}
EXPORT_SYMBOL(__fou_build_header);
int __gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, __be16 *sport, int type)
{
struct guehdr *guehdr;
size_t hdrlen, optlen = 0;
void *data;
bool need_priv = false;
int err;
if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
skb->ip_summed == CHECKSUM_PARTIAL) {
optlen += GUE_PLEN_REMCSUM;
type |= SKB_GSO_TUNNEL_REMCSUM;
need_priv = true;
}
optlen += need_priv ? GUE_LEN_PRIV : 0;
err = iptunnel_handle_offloads(skb, type);
if (err)
return err;
/* Get source port (based on flow hash) before skb_push */
*sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
hdrlen = sizeof(struct guehdr) + optlen;
skb_push(skb, hdrlen);
guehdr = (struct guehdr *)skb->data;
guehdr->control = 0;
guehdr->version = 0;
guehdr->hlen = optlen >> 2;
guehdr->flags = 0;
guehdr->proto_ctype = *protocol;
data = &guehdr[1];
if (need_priv) {
__be32 *flags = data;
guehdr->flags |= GUE_FLAG_PRIV;
*flags = 0;
data += GUE_LEN_PRIV;
if (type & SKB_GSO_TUNNEL_REMCSUM) {
u16 csum_start = skb_checksum_start_offset(skb);
__be16 *pd = data;
if (csum_start < hdrlen)
return -EINVAL;
csum_start -= hdrlen;
pd[0] = htons(csum_start);
pd[1] = htons(csum_start + skb->csum_offset);
if (!skb_is_gso(skb)) {
skb->ip_summed = CHECKSUM_NONE;
skb->encapsulation = 0;
}
*flags |= GUE_PFLAG_REMCSUM;
data += GUE_PLEN_REMCSUM;
}
}
return 0;
}
EXPORT_SYMBOL(__gue_build_header);
#ifdef CONFIG_NET_FOU_IP_TUNNELS
static void fou_build_udp(struct sk_buff *skb, struct ip_tunnel_encap *e,
struct flowi4 *fl4, u8 *protocol, __be16 sport)
{
struct udphdr *uh;
skb_push(skb, sizeof(struct udphdr));
skb_reset_transport_header(skb);
uh = udp_hdr(skb);
uh->dest = e->dport;
uh->source = sport;
uh->len = htons(skb->len);
udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
fl4->saddr, fl4->daddr, skb->len);
*protocol = IPPROTO_UDP;
}
static int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi4 *fl4)
{
int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
SKB_GSO_UDP_TUNNEL;
__be16 sport;
int err;
err = __fou_build_header(skb, e, protocol, &sport, type);
if (err)
return err;
fou_build_udp(skb, e, fl4, protocol, sport);
return 0;
}
static int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi4 *fl4)
{
int type = e->flags & TUNNEL_ENCAP_FLAG_CSUM ? SKB_GSO_UDP_TUNNEL_CSUM :
SKB_GSO_UDP_TUNNEL;
__be16 sport;
int err;
err = __gue_build_header(skb, e, protocol, &sport, type);
if (err)
return err;
fou_build_udp(skb, e, fl4, protocol, sport);
return 0;
}
static int gue_err_proto_handler(int proto, struct sk_buff *skb, u32 info)
{
const struct net_protocol *ipprot = rcu_dereference(inet_protos[proto]);
if (ipprot && ipprot->err_handler) {
if (!ipprot->err_handler(skb, info))
return 0;
}
return -ENOENT;
}
static int gue_err(struct sk_buff *skb, u32 info)
{
int transport_offset = skb_transport_offset(skb);
struct guehdr *guehdr;
size_t len, optlen;
int ret;
len = sizeof(struct udphdr) + sizeof(struct guehdr);
if (!pskb_may_pull(skb, transport_offset + len))
return -EINVAL;
guehdr = (struct guehdr *)&udp_hdr(skb)[1];
switch (guehdr->version) {
case 0: /* Full GUE header present */
break;
case 1: {
/* Direct encapsulation of IPv4 or IPv6 */
skb_set_transport_header(skb, -(int)sizeof(struct icmphdr));
switch (((struct iphdr *)guehdr)->version) {
case 4:
ret = gue_err_proto_handler(IPPROTO_IPIP, skb, info);
goto out;
#if IS_ENABLED(CONFIG_IPV6)
case 6:
ret = gue_err_proto_handler(IPPROTO_IPV6, skb, info);
goto out;
#endif
default:
ret = -EOPNOTSUPP;
goto out;
}
}
default: /* Undefined version */
return -EOPNOTSUPP;
}
if (guehdr->control)
return -ENOENT;
optlen = guehdr->hlen << 2;
if (!pskb_may_pull(skb, transport_offset + len + optlen))
return -EINVAL;
guehdr = (struct guehdr *)&udp_hdr(skb)[1];
if (validate_gue_flags(guehdr, optlen))
return -EINVAL;
/* Handling exceptions for direct UDP encapsulation in GUE would lead to
* recursion. Besides, this kind of encapsulation can't even be
* configured currently. Discard this.
*/
if (guehdr->proto_ctype == IPPROTO_UDP ||
guehdr->proto_ctype == IPPROTO_UDPLITE)
return -EOPNOTSUPP;
skb_set_transport_header(skb, -(int)sizeof(struct icmphdr));
ret = gue_err_proto_handler(guehdr->proto_ctype, skb, info);
out:
skb_set_transport_header(skb, transport_offset);
return ret;
}
static const struct ip_tunnel_encap_ops fou_iptun_ops = {
.encap_hlen = fou_encap_hlen,
.build_header = fou_build_header,
.err_handler = gue_err,
};
static const struct ip_tunnel_encap_ops gue_iptun_ops = {
.encap_hlen = gue_encap_hlen,
.build_header = gue_build_header,
.err_handler = gue_err,
};
static int ip_tunnel_encap_add_fou_ops(void)
{
int ret;
ret = ip_tunnel_encap_add_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
if (ret < 0) {
pr_err("can't add fou ops\n");
return ret;
}
ret = ip_tunnel_encap_add_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
if (ret < 0) {
pr_err("can't add gue ops\n");
ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
return ret;
}
return 0;
}
static void ip_tunnel_encap_del_fou_ops(void)
{
ip_tunnel_encap_del_ops(&fou_iptun_ops, TUNNEL_ENCAP_FOU);
ip_tunnel_encap_del_ops(&gue_iptun_ops, TUNNEL_ENCAP_GUE);
}
#else
static int ip_tunnel_encap_add_fou_ops(void)
{
return 0;
}
static void ip_tunnel_encap_del_fou_ops(void)
{
}
#endif
static __net_init int fou_init_net(struct net *net)
{
struct fou_net *fn = net_generic(net, fou_net_id);
INIT_LIST_HEAD(&fn->fou_list);
mutex_init(&fn->fou_lock);
return 0;
}
static __net_exit void fou_exit_net(struct net *net)
{
struct fou_net *fn = net_generic(net, fou_net_id);
struct fou *fou, *next;
/* Close all the FOU sockets */
mutex_lock(&fn->fou_lock);
list_for_each_entry_safe(fou, next, &fn->fou_list, list)
fou_release(fou);
mutex_unlock(&fn->fou_lock);
}
static struct pernet_operations fou_net_ops = {
.init = fou_init_net,
.exit = fou_exit_net,
.id = &fou_net_id,
.size = sizeof(struct fou_net),
};
static int __init fou_init(void)
{
int ret;
ret = register_pernet_device(&fou_net_ops);
if (ret)
goto exit;
ret = genl_register_family(&fou_nl_family);
if (ret < 0)
goto unregister;
ret = register_fou_bpf();
if (ret < 0)
goto kfunc_failed;
ret = ip_tunnel_encap_add_fou_ops();
if (ret == 0)
return 0;
kfunc_failed:
genl_unregister_family(&fou_nl_family);
unregister:
unregister_pernet_device(&fou_net_ops);
exit:
return ret;
}
static void __exit fou_fini(void)
{
ip_tunnel_encap_del_fou_ops();
genl_unregister_family(&fou_nl_family);
unregister_pernet_device(&fou_net_ops);
}
module_init(fou_init);
module_exit(fou_fini);
MODULE_AUTHOR("Tom Herbert <[email protected]>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Foo over UDP");
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