linux/net/ipv4/fou.c
Hannes Frederic Sowa 787d7ac308 udp: restrict offloads to one namespace
udp tunnel offloads tend to aggregate datagrams based on inner
headers. gro engine gets notified by tunnel implementations about
possible offloads. The match is solely based on the port number.

Imagine a tunnel bound to port 53, the offloading will look into all
DNS packets and tries to aggregate them based on the inner data found
within. This could lead to data corruption and malformed DNS packets.

While this patch minimizes the problem and helps an administrator to find
the issue by querying ip tunnel/fou, a better way would be to match on
the specific destination ip address so if a user space socket is bound
to the same address it will conflict.

Cc: Tom Herbert <tom@herbertland.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-10 17:28:24 -05:00

997 lines
21 KiB
C

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/genetlink.h>
#include <net/gue.h>
#include <net/ip.h>
#include <net/protocol.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/xfrm.h>
#include <uapi/linux/fou.h>
#include <uapi/linux/genetlink.h>
struct fou {
struct socket *sock;
u8 protocol;
u8 flags;
__be16 port;
u16 type;
struct udp_offload udp_offloads;
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 sk->sk_user_data;
}
static void fou_recv_pull(struct sk_buff *skb, size_t len)
{
struct iphdr *iph = ip_hdr(skb);
/* Remove 'len' bytes from the packet (UDP header and
* FOU header if present).
*/
iph->tot_len = htons(ntohs(iph->tot_len) - len);
__skb_pull(skb, len);
skb_postpull_rcsum(skb, udp_hdr(skb), len);
skb_reset_transport_header(skb);
}
static int fou_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct fou *fou = fou_from_sock(sk);
if (!fou)
return 1;
fou_recv_pull(skb, sizeof(struct udphdr));
return -fou->protocol;
}
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;
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];
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];
hdrlen = sizeof(struct guehdr) + optlen;
if (guehdr->version != 0 || validate_gue_flags(guehdr, optlen))
goto drop;
hdrlen = sizeof(struct guehdr) + optlen;
ip_hdr(skb)->tot_len = htons(ntohs(ip_hdr(skb)->tot_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);
__skb_pull(skb, sizeof(struct udphdr) + hdrlen);
skb_reset_transport_header(skb);
return -guehdr->proto_ctype;
drop:
kfree_skb(skb);
return 0;
}
static struct sk_buff **fou_gro_receive(struct sk_buff **head,
struct sk_buff *skb,
struct udp_offload *uoff)
{
const struct net_offload *ops;
struct sk_buff **pp = NULL;
u8 proto = NAPI_GRO_CB(skb)->proto;
const struct net_offload **offloads;
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[proto]);
if (!ops || !ops->callbacks.gro_receive)
goto out_unlock;
pp = ops->callbacks.gro_receive(head, skb);
out_unlock:
rcu_read_unlock();
return pp;
}
static int fou_gro_complete(struct sk_buff *skb, int nhoff,
struct udp_offload *uoff)
{
const struct net_offload *ops;
u8 proto = NAPI_GRO_CB(skb)->proto;
int err = -ENOSYS;
const struct net_offload **offloads;
udp_tunnel_gro_complete(skb, nhoff);
rcu_read_lock();
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_unlock;
err = ops->callbacks.gro_complete(skb, nhoff);
out_unlock:
rcu_read_unlock();
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 sk_buff **head,
struct sk_buff *skb,
struct udp_offload *uoff)
{
const struct net_offload **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 = container_of(uoff, struct fou, udp_offloads);
struct gro_remcsum grc;
skb_gro_remcsum_init(&grc);
off = skb_gro_offset(skb);
len = off + sizeof(*guehdr);
guehdr = skb_gro_header_fast(skb, off);
if (skb_gro_header_hard(skb, len)) {
guehdr = skb_gro_header_slow(skb, len, off);
if (unlikely(!guehdr))
goto out;
}
optlen = guehdr->hlen << 2;
len += optlen;
if (skb_gro_header_hard(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);
flush = 0;
for (p = *head; p; p = p->next) {
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;
}
}
rcu_read_lock();
offloads = NAPI_GRO_CB(skb)->is_ipv6 ? inet6_offloads : inet_offloads;
ops = rcu_dereference(offloads[guehdr->proto_ctype]);
if (WARN_ON_ONCE(!ops || !ops->callbacks.gro_receive))
goto out_unlock;
pp = ops->callbacks.gro_receive(head, skb);
out_unlock:
rcu_read_unlock();
out:
NAPI_GRO_CB(skb)->flush |= flush;
skb_gro_remcsum_cleanup(skb, &grc);
return pp;
}
static int gue_gro_complete(struct sk_buff *skb, int nhoff,
struct udp_offload *uoff)
{
const struct net_offload **offloads;
struct guehdr *guehdr = (struct guehdr *)(skb->data + nhoff);
const struct net_offload *ops;
unsigned int guehlen;
u8 proto;
int err = -ENOENT;
proto = guehdr->proto_ctype;
guehlen = sizeof(*guehdr) + (guehdr->hlen << 2);
rcu_read_lock();
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_unlock;
err = ops->callbacks.gro_complete(skb, nhoff + guehlen);
out_unlock:
rcu_read_unlock();
return err;
}
static int fou_add_to_port_list(struct net *net, struct fou *fou)
{
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->port == fout->port) {
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;
struct sock *sk = sock->sk;
if (sk->sk_family == AF_INET)
udp_del_offload(&fou->udp_offloads);
list_del(&fou->list);
udp_tunnel_sock_release(sock);
kfree_rcu(fou, rcu);
}
static int fou_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
{
udp_sk(sk)->encap_rcv = fou_udp_recv;
fou->protocol = cfg->protocol;
fou->udp_offloads.callbacks.gro_receive = fou_gro_receive;
fou->udp_offloads.callbacks.gro_complete = fou_gro_complete;
fou->udp_offloads.port = cfg->udp_config.local_udp_port;
fou->udp_offloads.ipproto = cfg->protocol;
return 0;
}
static int gue_encap_init(struct sock *sk, struct fou *fou, struct fou_cfg *cfg)
{
udp_sk(sk)->encap_rcv = gue_udp_recv;
fou->udp_offloads.callbacks.gro_receive = gue_gro_receive;
fou->udp_offloads.callbacks.gro_complete = gue_gro_complete;
fou->udp_offloads.port = cfg->udp_config.local_udp_port;
return 0;
}
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;
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->flags = cfg->flags;
fou->port = cfg->udp_config.local_udp_port;
/* Initial for fou type */
switch (cfg->type) {
case FOU_ENCAP_DIRECT:
err = fou_encap_init(sk, fou, cfg);
if (err)
goto error;
break;
case FOU_ENCAP_GUE:
err = gue_encap_init(sk, fou, cfg);
if (err)
goto error;
break;
default:
err = -EINVAL;
goto error;
}
fou->type = cfg->type;
udp_sk(sk)->encap_type = 1;
udp_encap_enable();
sk->sk_user_data = fou;
fou->sock = sock;
inet_inc_convert_csum(sk);
sk->sk_allocation = GFP_ATOMIC;
if (cfg->udp_config.family == AF_INET) {
err = udp_add_offload(net, &fou->udp_offloads);
if (err)
goto error;
}
err = fou_add_to_port_list(net, fou);
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);
__be16 port = cfg->udp_config.local_udp_port;
int err = -EINVAL;
struct fou *fou;
mutex_lock(&fn->fou_lock);
list_for_each_entry(fou, &fn->fou_list, list) {
if (fou->port == port) {
fou_release(fou);
err = 0;
break;
}
}
mutex_unlock(&fn->fou_lock);
return err;
}
static struct genl_family fou_nl_family = {
.id = GENL_ID_GENERATE,
.hdrsize = 0,
.name = FOU_GENL_NAME,
.version = FOU_GENL_VERSION,
.maxattr = FOU_ATTR_MAX,
.netnsok = true,
};
static struct nla_policy fou_nl_policy[FOU_ATTR_MAX + 1] = {
[FOU_ATTR_PORT] = { .type = NLA_U16, },
[FOU_ATTR_AF] = { .type = NLA_U8, },
[FOU_ATTR_IPPROTO] = { .type = NLA_U8, },
[FOU_ATTR_TYPE] = { .type = NLA_U8, },
[FOU_ATTR_REMCSUM_NOPARTIAL] = { .type = NLA_FLAG, },
};
static int parse_nl_config(struct genl_info *info,
struct fou_cfg *cfg)
{
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]);
if (family != AF_INET)
return -EINVAL;
cfg->udp_config.family = family;
}
if (info->attrs[FOU_ATTR_PORT]) {
__be16 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;
return 0;
}
static int fou_nl_cmd_add_port(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);
}
static int fou_nl_cmd_rm_port(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)
{
if (nla_put_u8(msg, FOU_ATTR_AF, fou->sock->sk->sk_family) ||
nla_put_be16(msg, FOU_ATTR_PORT, fou->port) ||
nla_put_u8(msg, FOU_ATTR_IPPROTO, fou->protocol) ||
nla_put_u8(msg, FOU_ATTR_TYPE, fou->type))
return -1;
if (fou->flags & FOU_F_REMCSUM_NOPARTIAL)
if (nla_put_flag(msg, FOU_ATTR_REMCSUM_NOPARTIAL))
return -1;
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;
}
static int fou_nl_cmd_get_port(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;
int ret;
ret = parse_nl_config(info, &cfg);
if (ret)
return ret;
port = cfg.udp_config.local_udp_port;
if (port == 0)
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 (port == fout->port) {
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;
}
static int fou_nl_dump(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 const struct genl_ops fou_nl_ops[] = {
{
.cmd = FOU_CMD_ADD,
.doit = fou_nl_cmd_add_port,
.policy = fou_nl_policy,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = FOU_CMD_DEL,
.doit = fou_nl_cmd_rm_port,
.policy = fou_nl_policy,
.flags = GENL_ADMIN_PERM,
},
{
.cmd = FOU_CMD_GET,
.doit = fou_nl_cmd_get_port,
.dumpit = fou_nl_dump,
.policy = fou_nl_policy,
},
};
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);
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);
uh->check = 0;
udp_set_csum(!(e->flags & TUNNEL_ENCAP_FLAG_CSUM), skb,
fl4->saddr, fl4->daddr, skb->len);
*protocol = IPPROTO_UDP;
}
int fou_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi4 *fl4)
{
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
__be16 sport;
skb = iptunnel_handle_offloads(skb, csum, type);
if (IS_ERR(skb))
return PTR_ERR(skb);
sport = e->sport ? : udp_flow_src_port(dev_net(skb->dev),
skb, 0, 0, false);
fou_build_udp(skb, e, fl4, protocol, sport);
return 0;
}
EXPORT_SYMBOL(fou_build_header);
int gue_build_header(struct sk_buff *skb, struct ip_tunnel_encap *e,
u8 *protocol, struct flowi4 *fl4)
{
bool csum = !!(e->flags & TUNNEL_ENCAP_FLAG_CSUM);
int type = csum ? SKB_GSO_UDP_TUNNEL_CSUM : SKB_GSO_UDP_TUNNEL;
struct guehdr *guehdr;
size_t hdrlen, optlen = 0;
__be16 sport;
void *data;
bool need_priv = false;
if ((e->flags & TUNNEL_ENCAP_FLAG_REMCSUM) &&
skb->ip_summed == CHECKSUM_PARTIAL) {
csum = false;
optlen += GUE_PLEN_REMCSUM;
type |= SKB_GSO_TUNNEL_REMCSUM;
need_priv = true;
}
optlen += need_priv ? GUE_LEN_PRIV : 0;
skb = iptunnel_handle_offloads(skb, csum, type);
if (IS_ERR(skb))
return PTR_ERR(skb);
/* 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;
}
}
fou_build_udp(skb, e, fl4, protocol, sport);
return 0;
}
EXPORT_SYMBOL(gue_build_header);
#ifdef CONFIG_NET_FOU_IP_TUNNELS
static const struct ip_tunnel_encap_ops fou_iptun_ops = {
.encap_hlen = fou_encap_hlen,
.build_header = fou_build_header,
};
static const struct ip_tunnel_encap_ops gue_iptun_ops = {
.encap_hlen = gue_encap_hlen,
.build_header = gue_build_header,
};
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_with_ops(&fou_nl_family,
fou_nl_ops);
if (ret < 0)
goto unregister;
ret = ip_tunnel_encap_add_fou_ops();
if (ret == 0)
return 0;
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 <therbert@google.com>");
MODULE_LICENSE("GPL");