11 Apr
2016
11 Apr
'16
4:09 p.m.
Send tunnel data on GTP-U socket insead of raw interface and
use existing iptunnel helpers for that.
Signed-off-by: Andreas Schultz <aschultz(a)tpip.net>
---
gtp.c | 241 ++++++++++++++++++++++++++++++++++++------------------------------
1 file changed, 132 insertions(+), 109 deletions(-)
diff --git a/gtp.c b/gtp.c
index 4ab2b01..bead51f 100644
--- a/gtp.c
+++ b/gtp.c
@@ -68,7 +68,6 @@ struct gtp_instance {
struct socket *sock1u;
struct net_device *dev;
- struct net_device *real_dev;
unsigned int hash_size;
struct hlist_head *tid_hash;
@@ -404,7 +403,6 @@ static int gtp_dev_init(struct net_device *dev)
{
struct gtp_instance *gti = netdev_priv(dev);
- dev->flags = IFF_NOARP;
gti->dev = dev;
dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
@@ -424,26 +422,34 @@ static void gtp_dev_uninit(struct net_device *dev)
#define IP_UDP_LEN (sizeof(struct iphdr) + sizeof(struct udphdr))
-static struct rtable *
-ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
- __be32 daddr, __be32 saddr, __u8 tos, int oif)
+static inline void init_gtp_flow(struct flowi4 *fl4,
+ const struct sock *sk,
+ __be32 daddr)
{
memset(fl4, 0, sizeof(*fl4));
- fl4->flowi4_oif = oif;
+ fl4->flowi4_oif = sk->sk_bound_dev_if;
fl4->daddr = daddr;
- fl4->saddr = saddr;
- fl4->flowi4_tos = tos;
- fl4->flowi4_proto = IPPROTO_UDP;
+ 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 inline void
-gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx, int payload_len)
+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 */
- skb_cow(skb, sizeof(*gtp0) + IP_UDP_LEN);
gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
gtp0->flags = 0x1e; /* V0, GTP-non-prime */
@@ -457,12 +463,12 @@ gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx, int
payload_len)
}
static inline void
-gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx, int payload_len)
+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 */
- skb_cow(skb, sizeof(*gtp1) + IP_UDP_LEN);
gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
/* Bits 8 7 6 5 4 3 2 1
@@ -502,6 +508,7 @@ gtp_iptunnel_xmit_stats(int err, struct net_device_stats *err_stats,
}
struct gtp_pktinfo {
+ struct sock *sk;
union {
struct iphdr *iph;
struct ipv6hdr *ip6h;
@@ -515,10 +522,12 @@ struct gtp_pktinfo {
};
static inline void
-gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, struct iphdr *iph,
+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;
@@ -530,7 +539,7 @@ 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 inet_sock *inet = inet_sk(gti->sock0->sk);
+ struct sock *sk;
struct iphdr *iph;
struct pdp_ctx *pctx;
struct rtable *rt;
@@ -549,14 +558,23 @@ static int gtp_ip4_prepare_xmit(struct sk_buff *skb, struct
net_device *dev,
netdev_dbg(dev, "found PDP context %p\n", pctx);
/* Obtain route for the new encapsulated GTP packet */
- rt = ip4_route_output_gtp(dev_net(dev), &fl4,
- pctx->sgsn_addr.ip4.s_addr,
- inet->inet_saddr, 0,
- gti->real_dev->ifindex);
+ 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 from ifidx=%d\n",
- &pctx->sgsn_addr.ip4.s_addr,
- gti->real_dev->ifindex);
+ netdev_dbg(dev, "no route to SSGN %pI4\n",
+ &pctx->sgsn_addr.ip4.s_addr);
dev->stats.tx_carrier_errors++;
goto err;
}
@@ -570,12 +588,11 @@ static int gtp_ip4_prepare_xmit(struct sk_buff *skb, struct
net_device *dev,
}
skb_dst_drop(skb);
- skb_dst_set(skb, &rt->dst);
/* This is similar to tnl_update_pmtu() */
df = iph->frag_off;
if (df) {
- mtu = dst_mtu(&rt->dst) - gti->real_dev->hard_header_len -
+ mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
sizeof(struct iphdr) - sizeof(struct udphdr);
switch (pctx->gtp_version) {
case GTP_V0:
@@ -586,10 +603,9 @@ static int gtp_ip4_prepare_xmit(struct sk_buff *skb, struct
net_device *dev,
break;
}
} else
- mtu = skb_dst(skb) ? dst_mtu(skb_dst(skb)) : dev->mtu;
+ mtu = dst_mtu(&rt->dst);
- if (skb_dst(skb))
- skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
+ 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)) {
@@ -600,7 +616,7 @@ static int gtp_ip4_prepare_xmit(struct sk_buff *skb, struct net_device
*dev,
goto err_rt;
}
- gtp_set_pktinfo_ipv4(pktinfo, iph, pctx, rt, &fl4, dev);
+ gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
return 0;
err_rt:
@@ -616,34 +632,23 @@ static int gtp_ip6_prepare_xmit(struct sk_buff *skb, struct
net_device *dev,
return 0;
}
-static inline void
-gtp_push_ip4hdr(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
+static inline int
+gtp_udp_tunnel_xmit(struct sk_buff *skb, __be16 port,
+ struct gtp_pktinfo *pktinfo)
{
- struct iphdr *iph;
-
- /* Push down and install the IP header. Similar to iptunnel_xmit() */
- 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 = htons(IP_DF);
- iph->protocol = IPPROTO_UDP;
- iph->tos = pktinfo->iph->tos;
- iph->daddr = pktinfo->fl4.daddr;
- iph->saddr = pktinfo->fl4.saddr;
- iph->ttl = ip4_dst_hoplimit(&pktinfo->rt->dst);
- __ip_select_ident(dev_net(pktinfo->rt->dst.dev), iph,
- (skb_shinfo(skb)->gso_segs ?: 1) - 1);
-
netdev_dbg(pktinfo->dev, "gtp -> IP src: %pI4 dst: %pI4\n",
- &iph->saddr, &iph->daddr);
+ &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 void
-gtp_push_ip6hdr(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
+static inline int
+gtp_ip6tunnel_xmit(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
{
/* TODO IPV6 support */
}
@@ -654,9 +659,17 @@ static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct
net_device *dev)
unsigned int payload_len;
struct gtp_pktinfo pktinfo;
unsigned int proto = ntohs(skb->protocol);
- int gtph_len, err;
+ 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);
@@ -669,56 +682,55 @@ static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct
net_device *dev)
if (err < 0)
goto tx_error;
- /* Annotate length of the encapsulated packet */
- payload_len = skb->len;
-
/* Push down GTP header */
switch (pktinfo.pctx->gtp_version) {
case GTP_V0:
- gtp0_push_header(skb, pktinfo.pctx, payload_len);
- break;
- case GTP_V1:
- gtp1_push_header(skb, pktinfo.pctx, payload_len);
- break;
- }
-
- /* Push down and install the UDP header. */
- skb_push(skb, sizeof(struct udphdr));
- skb_reset_transport_header(skb);
-
- uh = udp_hdr(skb);
- switch (pktinfo.pctx->gtp_version) {
- case GTP_V0:
- uh->source = uh->dest = htons(GTP0_PORT);
+ gtph_port = htons(GTP0_PORT);
gtph_len = sizeof(struct gtp0_header);
+
+ gtp0_push_header(skb, pktinfo.pctx);
break;
case GTP_V1:
- uh->source = uh->dest = htons(GTP1U_PORT);
+ gtph_port = htons(GTP1U_PORT);
gtph_len = sizeof(struct gtp1_header);
+
+ gtp1_push_header(skb, pktinfo.pctx);
break;
+ default:
+ goto tx_error;
}
- uh->len = htons(sizeof(struct udphdr) + payload_len + gtph_len);
- uh->check = 0;
-
- netdev_dbg(dev, "gtp -> UDP src: %u dst: %u (len %u)\n",
- ntohs(uh->source), ntohs(uh->dest), ntohs(uh->len));
-
switch (proto) {
case ETH_P_IP:
- gtp_push_ip4hdr(skb, &pktinfo);
+ err = gtp_udp_tunnel_xmit(skb, gtph_port, &pktinfo);
break;
case ETH_P_IPV6:
- gtp_push_ip6hdr(skb, &pktinfo);
+ /* Annotate length of the encapsulated packet */
+ payload_len = skb->len;
+
+ /* Push down and install the UDP header. */
+ skb_push(skb, sizeof(struct udphdr));
+ skb_reset_transport_header(skb);
+
+ uh = udp_hdr(skb);
+
+ uh->source = uh->dest = gtph_port;
+ uh->len = htons(sizeof(struct udphdr) + payload_len + gtph_len);
+ uh->check = 0;
+
+ netdev_dbg(dev, "gtp -> UDP src: %u dst: %u (len %u)\n",
+ ntohs(uh->source), ntohs(uh->dest), ntohs(uh->len));
+
+ nf_reset(skb);
+
+ netdev_dbg(dev, "Good, now packet leaving from GGSN to SGSN\n");
+
+ err = gtp_ip6tunnel_xmit(skb, &pktinfo);
break;
}
- rcu_read_unlock();
- nf_reset(skb);
-
- netdev_dbg(dev, "Good, now packet leaving from GGSN to SGSN\n");
+ rcu_read_unlock();
- err = ip_local_out(skb);
gtp_iptunnel_xmit_stats(err, &dev->stats, dev->tstats);
return NETDEV_TX_OK;
@@ -737,10 +749,26 @@ static const struct net_device_ops gtp_netdev_ops = {
static void gtp_link_setup(struct net_device *dev)
{
- dev->priv_flags |= IFF_NO_QUEUE;
-
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);
@@ -752,31 +780,20 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
struct nlattr *tb[], struct nlattr *data[])
{
struct gtp_net *gn;
- struct net_device *real_dev;
struct gtp_instance *gti;
int hashsize, err, fd0, fd1;
- if (!tb[IFLA_LINK])
- return -EINVAL;
-
- real_dev = __dev_get_by_index(src_net, nla_get_u32(tb[IFLA_LINK]));
- if (!real_dev)
- return -ENODEV;
-
- dev_hold(real_dev);
-
if (!tb[IFLA_MTU])
- dev->mtu = real_dev->mtu;
- else if (dev->mtu > real_dev->mtu)
- return -EINVAL;
+ dev->mtu = 1500;
gti = netdev_priv(dev);
- gti->real_dev = real_dev;
fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
- gtp_encap_enable(dev, gti, fd0, fd1);
+ err = gtp_encap_enable(dev, gti, fd0, fd1);
+ if (err < 0)
+ goto out_err;
if (!data[IFLA_GTP_HASHSIZE])
hashsize = 1024;
@@ -785,21 +802,28 @@ static int gtp_newlink(struct net *src_net, struct net_device *dev,
err = gtp_hashtable_new(gti, hashsize);
if (err < 0)
- return err;
+ goto out_encap;
err = register_netdevice(dev);
- if (err < 0)
- goto err1;
+ 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 interface\n");
+ netdev_dbg(dev, "registered new GTP interface\n");
return 0;
-err1:
- netdev_dbg(dev, "failed to register new netdev %d\n", err);
+
+out_hashtable:
gtp_hashtable_free(gti);
+
+out_encap:
+ gtp_encap_disable(gti);
+
+out_err:
return err;
}
@@ -809,7 +833,6 @@ static void gtp_dellink(struct net_device *dev, struct list_head
*head)
gtp_encap_disable(gti);
gtp_hashtable_free(gti);
- dev_put(gti->real_dev);
list_del_rcu(>i->list);
unregister_netdevice_queue(dev, head);
}
--
2.7.4