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gtp.c
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gtp.c
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/* GTP according to GSM TS 09.60 / 3GPP TS 29.060 */
/* (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
* Author: Harald Welte <hwelte@sysmocom.de>
* Pablo Neira Ayuso <pablo@gnumonks.org>
* Andreas Schultz <aschultz@travelping.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/version.h>
#include <linux/skbuff.h>
#include <linux/udp.h>
#include <linux/rculist.h>
#include <linux/jhash.h>
#include <linux/if_tunnel.h>
#include <linux/net.h>
#include <linux/file.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/ip.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/icmp.h>
#include <net/xfrm.h>
#include <net/genetlink.h>
#include <net/netns/generic.h>
#include "gtp.h"
#include "gtp_nl.h"
static u32 gtp_h_initval;
struct pdp_ctx {
struct hlist_node hlist_tid;
struct hlist_node hlist_addr;
union {
uint64_t tid;
struct {
uint64_t tid;
u16 flow;
} v0;
struct {
uint32_t i_tei;
uint32_t o_tei;
} v1;
} u;
u8 gtp_version;
u16 af;
union {
struct in6_addr ip6;
struct in_addr ip4;
} ms_addr;
union {
struct in6_addr ip6;
struct in_addr ip4;
} sgsn_addr;
atomic_t tx_seq;
struct rcu_head rcu_head;
};
/* One local instance of the GTP code base */
struct gtp_instance {
struct list_head list;
/* the socket */
struct socket *sock0;
struct socket *sock1u;
struct net_device *dev;
unsigned int hash_size;
struct hlist_head *tid_hash;
struct hlist_head *addr_hash;
};
static int gtp_net_id __read_mostly;
struct gtp_net {
struct list_head gtp_instance_list;
};
static void gtp_encap_disable(struct gtp_instance *gti);
static inline u32 gtp0_hashfn(u64 tid)
{
u32 *tid32 = (u32 *) &tid;
return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
}
static inline u32 gtp1u_hashfn(u32 tid)
{
return jhash_1word(tid, gtp_h_initval);
}
static inline u32 ipv4_hashfn(u32 ip)
{
return jhash_1word(ip, gtp_h_initval);
}
static inline u32 ipv6_hashfn(struct in6_addr *ip6)
{
return jhash2((const u32 *) &ip6->s6_addr32, sizeof(*ip6)/sizeof(u32),
gtp_h_initval);
}
/* resolve a PDP context structure based on the 64bit TID */
static struct pdp_ctx *gtp0_pdp_find(struct gtp_instance *gti, u64 tid)
{
struct hlist_head *head;
struct pdp_ctx *pdp;
head = >i->tid_hash[gtp0_hashfn(tid) % gti->hash_size];
hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
if (pdp->gtp_version == GTP_V0 && pdp->u.v0.tid == tid)
return pdp;
}
return NULL;
}
/* resolve a PDP context structure based on the 32bit TEI */
static struct pdp_ctx *gtp1_pdp_find(struct gtp_instance *gti, u32 tid)
{
struct hlist_head *head;
struct pdp_ctx *pdp;
head = >i->tid_hash[gtp1u_hashfn(tid) % gti->hash_size];
hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
if (pdp->gtp_version == GTP_V1 && pdp->u.v1.i_tei == tid)
return pdp;
}
return NULL;
}
/* resolve a PDP context based on IPv4 address of MS */
static struct pdp_ctx *ipv4_pdp_find(struct gtp_instance *gti,
u32 ms_addr)
{
struct hlist_head *head;
struct pdp_ctx *pdp;
head = >i->addr_hash[ipv4_hashfn(ms_addr) % gti->hash_size];
hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
if (pdp->af == AF_INET && pdp->ms_addr.ip4.s_addr == ms_addr)
return pdp;
}
return NULL;
}
/* resolve a PDP context based on IPv6 address of MS */
static struct pdp_ctx *ipv6_pdp_find(struct gtp_instance *gti,
struct in6_addr *ms_addr)
{
struct hlist_head *head;
struct pdp_ctx *pdp;
head = >i->addr_hash[ipv6_hashfn(ms_addr) % gti->hash_size];
hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
if (pdp->af == AF_INET6 &&
!memcmp(&pdp->ms_addr.ip6, ms_addr, sizeof(*ms_addr)))
return pdp;
}
return NULL;
}
/* resolve the GTP instance for a given sock */
static inline struct gtp_instance *sk_to_gti(struct sock *sk)
{
struct gtp_instance *gti;
if (!sk)
return NULL;
sock_hold(sk);
gti = (struct gtp_instance *) sk->sk_user_data;
if (!gti) {
sock_put(sk);
return NULL;
}
return gti;
}
/* Check if the inner IP header has the source address assigned to the
* current MS.
*/
static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
unsigned int hdrlen)
{
bool ret = false;
if (skb->protocol == ntohs(ETH_P_IP)) {
struct iphdr *iph;
if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
return false;
iph = (struct iphdr *)
(skb->data + hdrlen + sizeof(struct iphdr));
ret = (iph->saddr != pctx->ms_addr.ip4.s_addr);
} else if (skb->protocol == ntohs(ETH_P_IPV6)) {
struct ipv6hdr *ip6h;
if (!pskb_may_pull(skb, hdrlen + sizeof(struct ipv6hdr)))
return false;
ip6h = (struct ipv6hdr *)
(skb->data + hdrlen + sizeof(struct ipv6hdr));
ret = memcmp(&ip6h->saddr, &pctx->ms_addr.ip6,
sizeof(struct in6_addr)) == 0;
}
return ret;
}
/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated */
static int gtp0_udp_encap_recv(struct gtp_instance *gti, struct sk_buff *skb)
{
struct gtp0_header *gtp0;
struct pdp_ctx *pctx;
unsigned int hdrlen = sizeof(struct udphdr) + sizeof(*gtp0);
int ret = 0;
/* check for sufficient header size */
if (!pskb_may_pull(skb, hdrlen))
return -1;
gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
/* check for GTP Version 0 */
if ((gtp0->flags >> 5) != GTP_V0)
return 1;
/* check if it is T-PDU. if not -> userspace */
if (gtp0->type != GTP_TPDU)
return 1;
rcu_read_lock();
/* look-up the PDP context for the Tunnel ID */
pctx = gtp0_pdp_find(gti, be64_to_cpu(gtp0->tid));
if (!pctx) {
ret = -1;
goto out_rcu;
}
if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
ret = -1;
goto out_rcu;
}
/* get rid of the GTP + UDP headers */
__skb_pull(skb, hdrlen);
out_rcu:
rcu_read_unlock();
return ret;
}
static int gtp1u_udp_encap_recv(struct gtp_instance *gti, struct sk_buff *skb)
{
struct gtp1_header *gtp1;
struct pdp_ctx *pctx;
unsigned int hdrlen = sizeof(struct udphdr) + sizeof(*gtp1);
int ret = 0;
/* check for sufficient header size */
if (!pskb_may_pull(skb, hdrlen))
return -1;
gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
/* check for GTP Version 1 */
if ((gtp1->flags >> 5) != GTP_V1)
return 1;
/* check if it is T-PDU. */
if (gtp1->type != GTP_TPDU)
return 1;
/* From 29.060: "This field shall be present if and only if any one or
* more of the S, PN and E flags are set.".
*
* If any of the bit is set, then the remaining ones also have to be
* set.
*/
if (gtp1->flags & GTP1_F_MASK)
hdrlen += 4;
/* check for sufficient header size for extension */
if (!pskb_may_pull(skb, hdrlen))
return -1;
/* look-up the PDP context for the Tunnel ID */
rcu_read_lock();
pctx = gtp1_pdp_find(gti, ntohl(gtp1->tid));
if (!pctx) {
ret = -1;
goto out_rcu;
}
if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
ret = -1;
goto out_rcu;
}
/* get rid of the UDP + GTP header + extensions */
__skb_pull(skb, hdrlen);
out_rcu:
rcu_read_unlock();
return ret;
}
static void gtp_udp_encap_destroy(struct sock *sk)
{
struct gtp_instance *gti = sk_to_gti(sk);
if (gti) {
gtp_encap_disable(gti);
sock_put(sk);
}
}
/* UDP encapsulation receive handler. See net/ipv4/udp.c.
* Return codes: 0: success, <0: error, >0: passed up to userspace UDP.
*/
static int gtp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
{
struct gtp_instance *gti;
int ret;
/* resolve the GTP instance to which the socket belongs */
gti = sk_to_gti(sk);
if (!gti)
goto user;
netdev_dbg(gti->dev, "encap_recv %p\n", sk);
switch (udp_sk(sk)->encap_type) {
case UDP_ENCAP_GTP0:
netdev_dbg(gti->dev, "received GTP0 packet\n");
ret = gtp0_udp_encap_recv(gti, skb);
break;
case UDP_ENCAP_GTP1U:
netdev_dbg(gti->dev, "received GTP1U packet\n");
ret = gtp1u_udp_encap_recv(gti, skb);
break;
default:
ret = -1; /* shouldn't happen */
}
switch (ret) {
case 1:
netdev_dbg(gti->dev, "pass up to the process\n");
goto user_put;
case 0:
netdev_dbg(gti->dev, "forwarding packet from GGSN to uplink\n");
break;
case -1:
netdev_dbg(gti->dev, "GTP packet has been dropped\n");
goto drop;
}
/* Now that the UDP and the GTP header have been removed, set up the
* new network header. This is required by the upper later to
* calculate the transport header.
*/
skb_reset_network_header(skb);
/* re-submit via virtual tunnel device into regular network stack */
secpath_reset(skb);
skb_dst_drop(skb);
nf_reset(skb);
skb->dev = gti->dev;
/* Force the upper layers to verify it. */
skb->ip_summed = CHECKSUM_NONE;
netif_rx(skb);
sock_put(sk);
return 0;
drop:
kfree_skb(skb);
return 0;
user_put:
sock_put(sk);
user:
return 1;
}
static int gtp_dev_init(struct net_device *dev)
{
struct gtp_instance *gti = netdev_priv(dev);
gti->dev = dev;
dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
if (!dev->tstats)
return -ENOMEM;
return 0;
}
static void gtp_dev_uninit(struct net_device *dev)
{
struct gtp_instance *gti = netdev_priv(dev);
gtp_encap_disable(gti);
free_percpu(dev->tstats);
}
#define IP_UDP_LEN (sizeof(struct iphdr) + sizeof(struct udphdr))
static inline void init_gtp_flow(struct flowi4 *fl4,
const struct sock *sk,
__be32 daddr)
{
memset(fl4, 0, sizeof(*fl4));
fl4->flowi4_oif = sk->sk_bound_dev_if;
fl4->daddr = daddr;
fl4->saddr = inet_sk(sk)->inet_saddr;
fl4->flowi4_tos = RT_CONN_FLAGS(sk);
fl4->flowi4_proto = sk->sk_protocol;
}
static struct rtable *
ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
const struct sock *sk,
__be32 daddr)
{
init_gtp_flow(fl4, sk, daddr);
return ip_route_output_key(net, fl4);
}
static struct dst_entry *
ip6_route_output_gtp(struct net *net, struct flowi6 *fl6,
const struct sock *sk,
struct in6_addr *daddr)
{
memset(fl6, 0, sizeof(*fl6));
fl6->flowi6_oif = sk->sk_bound_dev_if;
fl6->daddr = *daddr;
fl6->saddr = inet6_sk(sk)->saddr;
fl6->flowi6_tos = RT_CONN_FLAGS(sk);
fl6->flowi6_proto = sk->sk_protocol;
return ip6_route_output(net, NULL, fl6);
}
static inline void
gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
{
struct gtp0_header *gtp0;
int payload_len = skb->len;
/* ensure there is sufficient headroom */
gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
gtp0->flags = 0x1e; /* V0, GTP-non-prime */
gtp0->type = GTP_TPDU;
gtp0->length = htons(payload_len);
gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq)-1) % 0xffff);
gtp0->flow = htons(pctx->u.v0.flow);
gtp0->number = 0xFF;
gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xFF;
gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
}
static inline void
gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
{
struct gtp1_header *gtp1;
int payload_len = skb->len;
/* ensure there is sufficient headroom */
gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
/* Bits 8 7 6 5 4 3 2 1
* +--+--+--+--+--+--+--+--+
* |version |PT| 1| E| S|PN|
* +--+--+--+--+--+--+--+--+
* 0 0 1 1 1 0 0 0
*/
gtp1->flags = 0x38; /* V1, GTP-non-prime */
gtp1->type = GTP_TPDU;
gtp1->length = htons(payload_len);
gtp1->tid = htonl(pctx->u.v1.o_tei);
/* TODO: Suppport for extension header, sequence number and N-PDU.
* Update the length field if any of them is available.
*/
}
/* From Linux kernel 3.13: iptunnel_xmit_stats() */
static inline void
gtp_iptunnel_xmit_stats(int err, struct net_device_stats *err_stats,
struct pcpu_sw_netstats __percpu *stats)
{
if (err > 0) {
struct pcpu_sw_netstats *tstats = this_cpu_ptr(stats);
u64_stats_update_begin(&tstats->syncp);
tstats->tx_bytes += err;
tstats->tx_packets++;
u64_stats_update_end(&tstats->syncp);
} else if (err < 0) {
err_stats->tx_errors++;
err_stats->tx_aborted_errors++;
} else {
err_stats->tx_dropped++;
}
}
struct gtp_pktinfo {
struct sock *sk;
union {
struct iphdr *iph;
struct ipv6hdr *ip6h;
};
union {
struct flowi4 fl4;
struct flowi6 fl6;
};
union {
struct rtable *rt;
struct dst_entry *ndst;
};
struct pdp_ctx *pctx;
struct net_device *dev;
};
static inline void
gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, struct sock *sk,
struct iphdr *iph,
struct pdp_ctx *pctx, struct rtable *rt,
struct flowi4 *fl4, struct net_device *dev)
{
pktinfo->sk = sk;
pktinfo->iph = iph;
pktinfo->pctx = pctx;
pktinfo->rt = rt;
pktinfo->fl4 = *fl4;
pktinfo->dev = dev;
}
static int gtp_ip4_prepare_xmit(struct sk_buff *skb, struct net_device *dev,
struct gtp_pktinfo *pktinfo)
{
struct gtp_instance *gti = netdev_priv(dev);
struct sock *sk;
struct iphdr *iph;
struct pdp_ctx *pctx;
struct rtable *rt;
struct flowi4 fl4;
int df, mtu;
/* Read the IP destination address and resolve the PDP context.
* Prepend PDP header with TEI/TID from PDP ctx.
*/
iph = ip_hdr(skb);
pctx = ipv4_pdp_find(gti, iph->daddr);
if (!pctx) {
netdev_dbg(dev, "no PDP ctx found for this packet, skip\n");
return -ENOENT;
}
netdev_dbg(dev, "found PDP context %p\n", pctx);
/* Obtain route for the new encapsulated GTP packet */
switch (pctx->gtp_version) {
case GTP_V0:
sk = gti->sock0->sk;
break;
case GTP_V1:
sk = gti->sock1u->sk;
break;
default:
return -ENOENT;
}
rt = ip4_route_output_gtp(sock_net(sk), &fl4,
gti->sock0->sk,
pctx->sgsn_addr.ip4.s_addr);
if (IS_ERR(rt)) {
netdev_dbg(dev, "no route to SSGN %pI4\n",
&pctx->sgsn_addr.ip4.s_addr);
dev->stats.tx_carrier_errors++;
goto err;
}
/* There is a routing loop */
if (rt->dst.dev == dev) {
netdev_dbg(dev, "circular route to SSGN %pI4\n",
&pctx->sgsn_addr.ip4.s_addr);
dev->stats.collisions++;
goto err_rt;
}
skb_dst_drop(skb);
/* This is similar to tnl_update_pmtu() */
df = iph->frag_off;
if (df) {
mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
sizeof(struct iphdr) - sizeof(struct udphdr);
switch (pctx->gtp_version) {
case GTP_V0:
mtu -= sizeof(struct gtp0_header);
break;
case GTP_V1:
mtu -= sizeof(struct gtp1_header);
break;
}
} else
mtu = dst_mtu(&rt->dst);
rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
mtu < ntohs(iph->tot_len)) {
netdev_dbg(dev, "packet too big, fragmentation needed\n");
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
goto err_rt;
}
gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
return 0;
err_rt:
ip_rt_put(rt);
err:
return -EBADMSG;
}
static inline void
gtp_set_pktinfo_ipv6(struct gtp_pktinfo *pktinfo, struct sock *sk,
struct ipv6hdr *ip6h,
struct pdp_ctx *pctx, struct dst_entry *ndst,
struct flowi6 *fl6, struct net_device *dev)
{
pktinfo->sk = sk;
pktinfo->ip6h = ip6h;
pktinfo->pctx = pctx;
pktinfo->ndst = ndst;
pktinfo->fl6 = *fl6;
pktinfo->dev = dev;
}
static int gtp_ip6_prepare_xmit(struct sk_buff *skb, struct net_device *dev,
struct gtp_pktinfo *pktinfo)
{
struct gtp_instance *gti = netdev_priv(dev);
struct sock *sk;
struct ipv6hdr *ipv6h;
struct pdp_ctx *pctx;
struct dst_entry *ndst;
struct flowi6 fl6;
int mtu;
/* Read the IP destination address and resolve the PDP context.
* Prepend PDP header with TEI/TID from PDP ctx.
*/
ipv6h = ipv6_hdr(skb);
pctx = ipv6_pdp_find(gti, &ipv6h->daddr);
if (!pctx) {
netdev_dbg(dev, "no PDP ctx found for this packet, skip\n");
return -ENOENT;
}
netdev_dbg(dev, "found PDP context %p\n", pctx);
/* Obtain route for the new encapsulated GTP packet */
switch (pctx->gtp_version) {
case GTP_V0:
sk = gti->sock0->sk;
break;
case GTP_V1:
sk = gti->sock1u->sk;
break;
default:
return -ENOENT;
}
ndst = ip6_route_output_gtp(sock_net(sk), &fl6,
gti->sock0->sk,
&pctx->sgsn_addr.ip6);
if (IS_ERR(ndst)) {
netdev_dbg(dev, "no route to SSGN %pI6\n",
&pctx->sgsn_addr.ip6.s6_addr);
dev->stats.tx_carrier_errors++;
goto err;
}
/* There is a routing loop */
if (ndst->dev == dev) {
netdev_dbg(dev, "circular route to SSGN %pI6\n",
&pctx->sgsn_addr.ip6);
dev->stats.collisions++;
goto err_dst;
}
skb_dst_drop(skb);
mtu = dst_mtu(ndst) - dev->hard_header_len -
sizeof(struct ipv6hdr) - sizeof(struct udphdr);
switch (pctx->gtp_version) {
case GTP_V0:
mtu -= sizeof(struct gtp0_header);
break;
case GTP_V1:
mtu -= sizeof(struct gtp1_header);
break;
}
ndst->ops->update_pmtu(ndst, NULL, skb, mtu);
if (!skb_is_gso(skb) && skb->len > mtu) {
netdev_dbg(dev, "packet too big, fragmentation needed\n");
memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
htonl(mtu));
goto err_dst;
}
gtp_set_pktinfo_ipv6(pktinfo, sk, ipv6h, pctx, ndst, &fl6, dev);
return 0;
err_dst:
dst_release(ndst);
err:
return -EBADMSG;
}
static inline int
gtp_udp_tunnel_xmit(struct sk_buff *skb, __be16 port,
struct gtp_pktinfo *pktinfo)
{
netdev_dbg(pktinfo->dev, "gtp -> IP src: %pI4 dst: %pI4\n",
&pktinfo->iph->saddr, &pktinfo->iph->daddr);
return udp_tunnel_xmit_skb(pktinfo->rt, pktinfo->sk, skb,
pktinfo->fl4.saddr,
pktinfo->fl4.daddr,
pktinfo->iph->tos,
ip4_dst_hoplimit(&pktinfo->rt->dst),
htons(IP_DF), port, port, true, false);
}
static inline int
gtp_ip6tunnel_xmit(struct sk_buff *skb, __be16 port,
struct gtp_pktinfo *pktinfo)
{
netdev_dbg(pktinfo->dev, "gtp -> IP src: %pI6 dst: %pI6\n",
&pktinfo->ip6h->saddr, &pktinfo->ip6h->daddr);
return udp_tunnel6_xmit_skb(pktinfo->ndst, pktinfo->sk, skb,
pktinfo->ndst->dev,
&pktinfo->fl6.saddr,
&pktinfo->fl6.daddr,
0,
ip6_dst_hoplimit(pktinfo->ndst),
port, port, false);
}
static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct gtp_pktinfo pktinfo;
unsigned int proto = ntohs(skb->protocol);
int gtph_len, err = -EINVAL;
__be16 gtph_port;
rcu_read_lock();
/* ensure there is sufficient headroom */
if (skb_cow_head(skb, dev->needed_headroom))
goto tx_error;
skb_reset_inner_headers(skb);
switch (proto) {
case ETH_P_IP:
err = gtp_ip4_prepare_xmit(skb, dev, &pktinfo);
break;
case ETH_P_IPV6:
err = gtp_ip6_prepare_xmit(skb, dev, &pktinfo);
break;
}
if (err < 0)
goto tx_error;
/* Push down GTP header */
switch (pktinfo.pctx->gtp_version) {
case GTP_V0:
gtph_port = htons(GTP0_PORT);
gtph_len = sizeof(struct gtp0_header);
gtp0_push_header(skb, pktinfo.pctx);
break;
case GTP_V1:
gtph_port = htons(GTP1U_PORT);
gtph_len = sizeof(struct gtp1_header);
gtp1_push_header(skb, pktinfo.pctx);
break;
default:
goto tx_error;
}
switch (proto) {
case ETH_P_IP:
err = gtp_udp_tunnel_xmit(skb, gtph_port, &pktinfo);
break;
case ETH_P_IPV6:
err = gtp_ip6tunnel_xmit(skb, gtph_port, &pktinfo);
break;
}
rcu_read_unlock();
gtp_iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
return NETDEV_TX_OK;
tx_error:
rcu_read_unlock();
dev->stats.tx_errors++;
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static const struct net_device_ops gtp_netdev_ops = {
.ndo_init = gtp_dev_init,
.ndo_uninit = gtp_dev_uninit,
.ndo_start_xmit = gtp_dev_xmit,
};
static void gtp_link_setup(struct net_device *dev)
{
dev->netdev_ops = >p_netdev_ops;
dev->destructor = free_netdev;
dev->hard_header_len = 0;
dev->addr_len = 0;
/* Zero header length */
dev->type = ARPHRD_NONE;
dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
dev->tx_queue_len = 1000;
dev->priv_flags |= IFF_NO_QUEUE;
dev->features |= NETIF_F_LLTX;
netif_keep_dst(dev);
dev->needed_headroom = LL_MAX_HEADER
+ sizeof(struct iphdr)
+ sizeof(struct udphdr)
+ sizeof(struct gtp0_header);
}
static int gtp_hashtable_new(struct gtp_instance *gti, int hsize);
static void gtp_hashtable_free(struct gtp_instance *gti);
static int gtp_encap_enable(struct net_device *dev, struct gtp_instance *gti,
int fd_gtp0, int fd_gtp1);
static int gtp_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct gtp_net *gn;
struct gtp_instance *gti;
int hashsize, err, fd0, fd1;
if (!tb[IFLA_MTU])
dev->mtu = 1500;
gti = netdev_priv(dev);
fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
err = gtp_encap_enable(dev, gti, fd0, fd1);
if (err < 0)
goto out_err;
if (!data[IFLA_GTP_HASHSIZE])
hashsize = 1024;
else
hashsize = nla_get_u32(data[IFLA_GTP_HASHSIZE]);
err = gtp_hashtable_new(gti, hashsize);
if (err < 0)
goto out_encap;
err = register_netdevice(dev);
if (err < 0) {
netdev_dbg(dev, "failed to register new netdev %d\n", err);
goto out_hashtable;
}
gn = net_generic(dev_net(dev), gtp_net_id);
list_add_rcu(>i->list, &gn->gtp_instance_list);
netdev_dbg(dev, "registered new GTP interface\n");
return 0;
out_hashtable:
gtp_hashtable_free(gti);
out_encap:
gtp_encap_disable(gti);
out_err:
return err;
}
static void gtp_dellink(struct net_device *dev, struct list_head *head)
{
struct gtp_instance *gti = netdev_priv(dev);
gtp_encap_disable(gti);
gtp_hashtable_free(gti);
list_del_rcu(>i->list);
unregister_netdevice_queue(dev, head);
}
static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
[IFLA_GTP_FD0] = { .type = NLA_U32 },
[IFLA_GTP_FD1] = { .type = NLA_U32 },
[IFLA_GTP_HASHSIZE] = { .type = NLA_U32 },
};
static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
{
if (!data || !data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
return -EINVAL;
return 0;
}
static size_t gtp_get_size(const struct net_device *dev)
{
return nla_total_size(sizeof(__u32)); /* IFLA_GTP_HASHSIZE */
}
static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
{
struct gtp_instance *gti = netdev_priv(dev);
if (nla_put_u32(skb, IFLA_GTP_HASHSIZE, gti->hash_size))
goto nla_put_failure;
return 0;
nla_put_failure:
return -EMSGSIZE;
}
static struct rtnl_link_ops gtp_link_ops __read_mostly = {
.kind = "gtp",
.maxtype = IFLA_GTP_MAX,
.policy = gtp_policy,
.priv_size = sizeof(struct gtp_instance),
.setup = gtp_link_setup,
.validate = gtp_validate,
.newlink = gtp_newlink,
.dellink = gtp_dellink,
.get_size = gtp_get_size,
.fill_info = gtp_fill_info,
};
static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[])
{
struct net *net;
/* Examine the link attributes and figure out which
* network namespace we are talking about.
*/
if (tb[GTPA_NET_NS_FD])
net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));