--- /dev/null
+/* GTP according to GSM TS 09.60 / 3GPP TS 29.060
+ *
+ * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
+ * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
+ *
+ * Author: Harald Welte <hwelte@sysmocom.de>
+ * Pablo Neira Ayuso <pablo@netfilter.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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#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 <linux/gtp.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 <net/gtp.h>
+
+/* An active session for the subscriber. */
+struct pdp_ctx {
+ struct hlist_node hlist_tid;
+ struct hlist_node hlist_addr;
+
+ union {
+ u64 tid;
+ struct {
+ u64 tid;
+ u16 flow;
+ } v0;
+ struct {
+ u32 i_tei;
+ u32 o_tei;
+ } v1;
+ } u;
+ u8 gtp_version;
+ u16 af;
+
+ struct in_addr ms_addr_ip4;
+ struct in_addr sgsn_addr_ip4;
+
+ atomic_t tx_seq;
+ struct rcu_head rcu_head;
+};
+
+/* One instance of the GTP device. */
+struct gtp_dev {
+ struct list_head list;
+
+ struct socket *sock0;
+ struct socket *sock1u;
+
+ struct net *net;
+ 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_dev_list;
+};
+
+static u32 gtp_h_initval;
+
+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(__be32 ip)
+{
+ return jhash_1word((__force u32)ip, gtp_h_initval);
+}
+
+/* Resolve a PDP context structure based on the 64bit TID. */
+static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
+{
+ struct hlist_head *head;
+ struct pdp_ctx *pdp;
+
+ head = >p->tid_hash[gtp0_hashfn(tid) % gtp->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_dev *gtp, u32 tid)
+{
+ struct hlist_head *head;
+ struct pdp_ctx *pdp;
+
+ head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->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_dev *gtp, __be32 ms_addr)
+{
+ struct hlist_head *head;
+ struct pdp_ctx *pdp;
+
+ head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->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;
+}
+
+static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
+ unsigned int hdrlen)
+{
+ struct iphdr *iph;
+
+ if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
+ return false;
+
+ iph = (struct iphdr *)(skb->data + hdrlen + sizeof(struct iphdr));
+
+ return iph->saddr != pctx->ms_addr_ip4.s_addr;
+}
+
+/* Check if the inner IP source address in this packet is assigned to any
+ * existing mobile subscriber.
+ */
+static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
+ unsigned int hdrlen)
+{
+ switch (ntohs(skb->protocol)) {
+ case ETH_P_IP:
+ return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
+ }
+ return false;
+}
+
+/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
+static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
+ bool xnet)
+{
+ unsigned int hdrlen = sizeof(struct udphdr) +
+ sizeof(struct gtp0_header);
+ struct gtp0_header *gtp0;
+ struct pdp_ctx *pctx;
+ int ret = 0;
+
+ if (!pskb_may_pull(skb, hdrlen))
+ return -1;
+
+ gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
+
+ if ((gtp0->flags >> 5) != GTP_V0)
+ return 1;
+
+ if (gtp0->type != GTP_TPDU)
+ return 1;
+
+ rcu_read_lock();
+ pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
+ if (!pctx) {
+ netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
+ ret = -1;
+ goto out_rcu;
+ }
+
+ if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
+ netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
+ ret = -1;
+ goto out_rcu;
+ }
+ rcu_read_unlock();
+
+ /* Get rid of the GTP + UDP headers. */
+ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
+out_rcu:
+ rcu_read_unlock();
+ return ret;
+}
+
+static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
+ bool xnet)
+{
+ unsigned int hdrlen = sizeof(struct udphdr) +
+ sizeof(struct gtp1_header);
+ struct gtp1_header *gtp1;
+ struct pdp_ctx *pctx;
+ int ret = 0;
+
+ if (!pskb_may_pull(skb, hdrlen))
+ return -1;
+
+ gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
+
+ if ((gtp1->flags >> 5) != GTP_V1)
+ return 1;
+
+ 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;
+
+ /* Make sure the header is larger enough, including extensions. */
+ if (!pskb_may_pull(skb, hdrlen))
+ return -1;
+
+ rcu_read_lock();
+ pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
+ if (!pctx) {
+ netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
+ ret = -1;
+ goto out_rcu;
+ }
+
+ if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
+ netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
+ ret = -1;
+ goto out_rcu;
+ }
+ rcu_read_unlock();
+
+ /* Get rid of the GTP + UDP headers. */
+ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
+out_rcu:
+ rcu_read_unlock();
+ return ret;
+}
+
+static void gtp_encap_disable(struct gtp_dev *gtp)
+{
+ if (gtp->sock0 && gtp->sock0->sk) {
+ udp_sk(gtp->sock0->sk)->encap_type = 0;
+ rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
+ }
+ if (gtp->sock1u && gtp->sock1u->sk) {
+ udp_sk(gtp->sock1u->sk)->encap_type = 0;
+ rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
+ }
+
+ gtp->sock0 = NULL;
+ gtp->sock1u = NULL;
+}
+
+static void gtp_encap_destroy(struct sock *sk)
+{
+ struct gtp_dev *gtp;
+
+ gtp = rcu_dereference_sk_user_data(sk);
+ if (gtp)
+ gtp_encap_disable(gtp);
+}
+
+/* UDP encapsulation receive handler. See net/ipv4/udp.c.
+ * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
+ */
+static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
+{
+ struct pcpu_sw_netstats *stats;
+ struct gtp_dev *gtp;
+ bool xnet;
+ int ret;
+
+ gtp = rcu_dereference_sk_user_data(sk);
+ if (!gtp)
+ return 1;
+
+ netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
+
+ xnet = !net_eq(gtp->net, dev_net(gtp->dev));
+
+ switch (udp_sk(sk)->encap_type) {
+ case UDP_ENCAP_GTP0:
+ netdev_dbg(gtp->dev, "received GTP0 packet\n");
+ ret = gtp0_udp_encap_recv(gtp, skb, xnet);
+ break;
+ case UDP_ENCAP_GTP1U:
+ netdev_dbg(gtp->dev, "received GTP1U packet\n");
+ ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
+ break;
+ default:
+ ret = -1; /* Shouldn't happen. */
+ }
+
+ switch (ret) {
+ case 1:
+ netdev_dbg(gtp->dev, "pass up to the process\n");
+ return 1;
+ case 0:
+ netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
+ break;
+ case -1:
+ netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
+ kfree_skb(skb);
+ return 0;
+ }
+
+ /* Now that the UDP and the GTP header have been removed, set up the
+ * new network header. This is required by the upper layer to
+ * calculate the transport header.
+ */
+ skb_reset_network_header(skb);
+
+ skb->dev = gtp->dev;
+
+ stats = this_cpu_ptr(gtp->dev->tstats);
+ u64_stats_update_begin(&stats->syncp);
+ stats->rx_packets++;
+ stats->rx_bytes += skb->len;
+ u64_stats_update_end(&stats->syncp);
+
+ netif_rx(skb);
+
+ return 0;
+}
+
+static int gtp_dev_init(struct net_device *dev)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+
+ gtp->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_dev *gtp = netdev_priv(dev);
+
+ gtp_encap_disable(gtp);
+ free_percpu(dev->tstats);
+}
+
+static struct rtable *ip4_route_output_gtp(struct net *net, 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;
+
+ return ip_route_output_key(net, fl4);
+}
+
+static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
+{
+ int payload_len = skb->len;
+ struct gtp0_header *gtp0;
+
+ 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)
+{
+ int payload_len = skb->len;
+ struct gtp1_header *gtp1;
+
+ 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.
+ */
+}
+
+struct gtp_pktinfo {
+ struct sock *sk;
+ struct iphdr *iph;
+ struct flowi4 fl4;
+ struct rtable *rt;
+ struct pdp_ctx *pctx;
+ struct net_device *dev;
+ __be16 gtph_port;
+};
+
+static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
+{
+ switch (pktinfo->pctx->gtp_version) {
+ case GTP_V0:
+ pktinfo->gtph_port = htons(GTP0_PORT);
+ gtp0_push_header(skb, pktinfo->pctx);
+ break;
+ case GTP_V1:
+ pktinfo->gtph_port = htons(GTP1U_PORT);
+ gtp1_push_header(skb, pktinfo->pctx);
+ break;
+ }
+}
+
+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_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
+ struct gtp_pktinfo *pktinfo)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+ struct pdp_ctx *pctx;
+ struct rtable *rt;
+ struct flowi4 fl4;
+ struct iphdr *iph;
+ struct sock *sk;
+ __be16 df;
+ int 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(gtp, iph->daddr);
+ if (!pctx) {
+ netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
+ &iph->daddr);
+ return -ENOENT;
+ }
+ netdev_dbg(dev, "found PDP context %p\n", pctx);
+
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ if (gtp->sock0)
+ sk = gtp->sock0->sk;
+ else
+ sk = NULL;
+ break;
+ case GTP_V1:
+ if (gtp->sock1u)
+ sk = gtp->sock1u->sk;
+ else
+ sk = NULL;
+ break;
+ default:
+ return -ENOENT;
+ }
+
+ if (!sk) {
+ netdev_dbg(dev, "no userspace socket is available, skip\n");
+ return -ENOENT;
+ }
+
+ rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->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;
+ }
+
+ 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);
+ gtp_push_header(skb, pktinfo);
+
+ return 0;
+err_rt:
+ ip_rt_put(rt);
+err:
+ return -EBADMSG;
+}
+
+static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ unsigned int proto = ntohs(skb->protocol);
+ struct gtp_pktinfo pktinfo;
+ int err;
+
+ /* Ensure there is sufficient headroom. */
+ if (skb_cow_head(skb, dev->needed_headroom))
+ goto tx_err;
+
+ skb_reset_inner_headers(skb);
+
+ /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
+ rcu_read_lock();
+ switch (proto) {
+ case ETH_P_IP:
+ err = gtp_build_skb_ip4(skb, dev, &pktinfo);
+ break;
+ default:
+ err = -EOPNOTSUPP;
+ break;
+ }
+ rcu_read_unlock();
+
+ if (err < 0)
+ goto tx_err;
+
+ switch (proto) {
+ case ETH_P_IP:
+ netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
+ &pktinfo.iph->saddr, &pktinfo.iph->daddr);
+ 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),
+ pktinfo.gtph_port, pktinfo.gtph_port,
+ true, false);
+ break;
+ }
+
+ return NETDEV_TX_OK;
+tx_err:
+ 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,
+ .ndo_get_stats64 = ip_tunnel_get_stats64,
+};
+
+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->priv_flags |= IFF_NO_QUEUE;
+ dev->features |= NETIF_F_LLTX;
+ netif_keep_dst(dev);
+
+ /* Assume largest header, ie. GTPv0. */
+ dev->needed_headroom = LL_MAX_HEADER +
+ sizeof(struct iphdr) +
+ sizeof(struct udphdr) +
+ sizeof(struct gtp0_header);
+}
+
+static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
+static void gtp_hashtable_free(struct gtp_dev *gtp);
+static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
+ int fd_gtp0, int fd_gtp1, struct net *src_net);
+
+static int gtp_newlink(struct net *src_net, struct net_device *dev,
+ struct nlattr *tb[], struct nlattr *data[])
+{
+ int hashsize, err, fd0, fd1;
+ struct gtp_dev *gtp;
+ struct gtp_net *gn;
+
+ if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
+ return -EINVAL;
+
+ gtp = netdev_priv(dev);
+
+ fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
+ fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
+
+ err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net);
+ if (err < 0)
+ goto out_err;
+
+ if (!data[IFLA_GTP_PDP_HASHSIZE])
+ hashsize = 1024;
+ else
+ hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
+
+ err = gtp_hashtable_new(gtp, 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(>p->list, &gn->gtp_dev_list);
+
+ netdev_dbg(dev, "registered new GTP interface\n");
+
+ return 0;
+
+out_hashtable:
+ gtp_hashtable_free(gtp);
+out_encap:
+ gtp_encap_disable(gtp);
+out_err:
+ return err;
+}
+
+static void gtp_dellink(struct net_device *dev, struct list_head *head)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+
+ gtp_encap_disable(gtp);
+ gtp_hashtable_free(gtp);
+ list_del_rcu(>p->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_PDP_HASHSIZE] = { .type = NLA_U32 },
+};
+
+static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
+{
+ if (!data)
+ return -EINVAL;
+
+ return 0;
+}
+
+static size_t gtp_get_size(const struct net_device *dev)
+{
+ return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
+}
+
+static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+
+ if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->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_dev),
+ .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]));
+ else
+ net = get_net(src_net);
+
+ return net;
+}
+
+static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
+{
+ int i;
+
+ gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
+ if (gtp->addr_hash == NULL)
+ return -ENOMEM;
+
+ gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
+ if (gtp->tid_hash == NULL)
+ goto err1;
+
+ gtp->hash_size = hsize;
+
+ for (i = 0; i < hsize; i++) {
+ INIT_HLIST_HEAD(>p->addr_hash[i]);
+ INIT_HLIST_HEAD(>p->tid_hash[i]);
+ }
+ return 0;
+err1:
+ kfree(gtp->addr_hash);
+ return -ENOMEM;
+}
+
+static void gtp_hashtable_free(struct gtp_dev *gtp)
+{
+ struct pdp_ctx *pctx;
+ int i;
+
+ for (i = 0; i < gtp->hash_size; i++) {
+ hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
+ hlist_del_rcu(&pctx->hlist_tid);
+ hlist_del_rcu(&pctx->hlist_addr);
+ kfree_rcu(pctx, rcu_head);
+ }
+ }
+ synchronize_rcu();
+ kfree(gtp->addr_hash);
+ kfree(gtp->tid_hash);
+}
+
+static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
+ int fd_gtp0, int fd_gtp1, struct net *src_net)
+{
+ struct udp_tunnel_sock_cfg tuncfg = {NULL};
+ struct socket *sock0, *sock1u;
+ int err;
+
+ netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
+
+ sock0 = sockfd_lookup(fd_gtp0, &err);
+ if (sock0 == NULL) {
+ netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
+ return -ENOENT;
+ }
+
+ if (sock0->sk->sk_protocol != IPPROTO_UDP) {
+ netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
+ err = -EINVAL;
+ goto err1;
+ }
+
+ sock1u = sockfd_lookup(fd_gtp1, &err);
+ if (sock1u == NULL) {
+ netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
+ err = -ENOENT;
+ goto err1;
+ }
+
+ if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
+ netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
+ err = -EINVAL;
+ goto err2;
+ }
+
+ netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
+
+ gtp->sock0 = sock0;
+ gtp->sock1u = sock1u;
+ gtp->net = src_net;
+
+ tuncfg.sk_user_data = gtp;
+ tuncfg.encap_rcv = gtp_encap_recv;
+ tuncfg.encap_destroy = gtp_encap_destroy;
+
+ tuncfg.encap_type = UDP_ENCAP_GTP0;
+ setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
+
+ tuncfg.encap_type = UDP_ENCAP_GTP1U;
+ setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
+
+ err = 0;
+err2:
+ sockfd_put(sock1u);
+err1:
+ sockfd_put(sock0);
+ return err;
+}
+
+static struct net_device *gtp_find_dev(struct net *net, int ifindex)
+{
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+ struct gtp_dev *gtp;
+
+ list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
+ if (ifindex == gtp->dev->ifindex)
+ return gtp->dev;
+ }
+ return NULL;
+}
+
+static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
+{
+ pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
+ pctx->af = AF_INET;
+ pctx->sgsn_addr_ip4.s_addr =
+ nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
+ pctx->ms_addr_ip4.s_addr =
+ nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
+
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
+ * label needs to be the same for uplink and downlink packets,
+ * so let's annotate this.
+ */
+ pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
+ pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
+ break;
+ case GTP_V1:
+ pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
+ pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
+ break;
+ default:
+ break;
+ }
+}
+
+static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
+{
+ struct gtp_dev *gtp = netdev_priv(dev);
+ u32 hash_ms, hash_tid = 0;
+ struct pdp_ctx *pctx;
+ bool found = false;
+ __be32 ms_addr;
+
+ ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
+ hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
+
+ hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) {
+ if (pctx->ms_addr_ip4.s_addr == ms_addr) {
+ found = true;
+ break;
+ }
+ }
+
+ if (found) {
+ if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
+ return -EEXIST;
+ if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
+ return -EOPNOTSUPP;
+
+ ipv4_pdp_fill(pctx, info);
+
+ if (pctx->gtp_version == GTP_V0)
+ netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
+ pctx->u.v0.tid, pctx);
+ else if (pctx->gtp_version == GTP_V1)
+ netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
+ pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
+
+ return 0;
+
+ }
+
+ pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
+ if (pctx == NULL)
+ return -ENOMEM;
+
+ ipv4_pdp_fill(pctx, info);
+ atomic_set(&pctx->tx_seq, 0);
+
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ /* TS 09.60: "The flow label identifies unambiguously a GTP
+ * flow.". We use the tid for this instead, I cannot find a
+ * situation in which this doesn't unambiguosly identify the
+ * PDP context.
+ */
+ hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
+ break;
+ case GTP_V1:
+ hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
+ break;
+ }
+
+ hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
+ hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
+
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
+ pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
+ &pctx->ms_addr_ip4, pctx);
+ break;
+ case GTP_V1:
+ netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
+ pctx->u.v1.i_tei, pctx->u.v1.o_tei,
+ &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
+ break;
+ }
+
+ return 0;
+}
+
+static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net_device *dev;
+ struct net *net;
+
+ if (!info->attrs[GTPA_VERSION] ||
+ !info->attrs[GTPA_LINK] ||
+ !info->attrs[GTPA_SGSN_ADDRESS] ||
+ !info->attrs[GTPA_MS_ADDRESS])
+ return -EINVAL;
+
+ switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
+ case GTP_V0:
+ if (!info->attrs[GTPA_TID] ||
+ !info->attrs[GTPA_FLOW])
+ return -EINVAL;
+ break;
+ case GTP_V1:
+ if (!info->attrs[GTPA_I_TEI] ||
+ !info->attrs[GTPA_O_TEI])
+ return -EINVAL;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ /* Check if there's an existing gtpX device to configure */
+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
+ if (dev == NULL)
+ return -ENODEV;
+
+ return ipv4_pdp_add(dev, info);
+}
+
+static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
+{
+ struct net_device *dev;
+ struct pdp_ctx *pctx;
+ struct gtp_dev *gtp;
+ struct net *net;
+
+ if (!info->attrs[GTPA_VERSION] ||
+ !info->attrs[GTPA_LINK])
+ return -EINVAL;
+
+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ /* Check if there's an existing gtpX device to configure */
+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
+ if (dev == NULL)
+ return -ENODEV;
+
+ gtp = netdev_priv(dev);
+
+ switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
+ case GTP_V0:
+ if (!info->attrs[GTPA_TID])
+ return -EINVAL;
+ pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
+ break;
+ case GTP_V1:
+ if (!info->attrs[GTPA_I_TEI])
+ return -EINVAL;
+ pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ if (pctx == NULL)
+ return -ENOENT;
+
+ if (pctx->gtp_version == GTP_V0)
+ netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
+ pctx->u.v0.tid, pctx);
+ else if (pctx->gtp_version == GTP_V1)
+ netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
+ pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
+
+ hlist_del_rcu(&pctx->hlist_tid);
+ hlist_del_rcu(&pctx->hlist_addr);
+ kfree_rcu(pctx, rcu_head);
+
+ return 0;
+}
+
+static struct genl_family gtp_genl_family = {
+ .id = GENL_ID_GENERATE,
+ .name = "gtp",
+ .version = 0,
+ .hdrsize = 0,
+ .maxattr = GTPA_MAX,
+ .netnsok = true,
+};
+
+static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
+ u32 type, struct pdp_ctx *pctx)
+{
+ void *genlh;
+
+ genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0,
+ type);
+ if (genlh == NULL)
+ goto nlmsg_failure;
+
+ if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
+ nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) ||
+ nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
+ goto nla_put_failure;
+
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
+ nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
+ goto nla_put_failure;
+ break;
+ case GTP_V1:
+ if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
+ nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
+ goto nla_put_failure;
+ break;
+ }
+ genlmsg_end(skb, genlh);
+ return 0;
+
+nlmsg_failure:
+nla_put_failure:
+ genlmsg_cancel(skb, genlh);
+ return -EMSGSIZE;
+}
+
+static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
+{
+ struct pdp_ctx *pctx = NULL;
+ struct net_device *dev;
+ struct sk_buff *skb2;
+ struct gtp_dev *gtp;
+ u32 gtp_version;
+ struct net *net;
+ int err;
+
+ if (!info->attrs[GTPA_VERSION] ||
+ !info->attrs[GTPA_LINK])
+ return -EINVAL;
+
+ gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
+ switch (gtp_version) {
+ case GTP_V0:
+ case GTP_V1:
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
+ if (IS_ERR(net))
+ return PTR_ERR(net);
+
+ /* Check if there's an existing gtpX device to configure */
+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
+ if (dev == NULL)
+ return -ENODEV;
+
+ gtp = netdev_priv(dev);
+
+ rcu_read_lock();
+ if (gtp_version == GTP_V0 &&
+ info->attrs[GTPA_TID]) {
+ u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
+
+ pctx = gtp0_pdp_find(gtp, tid);
+ } else if (gtp_version == GTP_V1 &&
+ info->attrs[GTPA_I_TEI]) {
+ u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
+
+ pctx = gtp1_pdp_find(gtp, tid);
+ } else if (info->attrs[GTPA_MS_ADDRESS]) {
+ __be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
+
+ pctx = ipv4_pdp_find(gtp, ip);
+ }
+
+ if (pctx == NULL) {
+ err = -ENOENT;
+ goto err_unlock;
+ }
+
+ skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
+ if (skb2 == NULL) {
+ err = -ENOMEM;
+ goto err_unlock;
+ }
+
+ err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
+ info->snd_seq, info->nlhdr->nlmsg_type, pctx);
+ if (err < 0)
+ goto err_unlock_free;
+
+ rcu_read_unlock();
+ return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
+
+err_unlock_free:
+ kfree_skb(skb2);
+err_unlock:
+ rcu_read_unlock();
+ return err;
+}
+
+static int gtp_genl_dump_pdp(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
+ struct net *net = sock_net(skb->sk);
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+ unsigned long tid = cb->args[1];
+ int i, k = cb->args[0], ret;
+ struct pdp_ctx *pctx;
+
+ if (cb->args[4])
+ return 0;
+
+ list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
+ if (last_gtp && last_gtp != gtp)
+ continue;
+ else
+ last_gtp = NULL;
+
+ for (i = k; i < gtp->hash_size; i++) {
+ hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
+ if (tid && tid != pctx->u.tid)
+ continue;
+ else
+ tid = 0;
+
+ ret = gtp_genl_fill_info(skb,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq,
+ cb->nlh->nlmsg_type, pctx);
+ if (ret < 0) {
+ cb->args[0] = i;
+ cb->args[1] = pctx->u.tid;
+ cb->args[2] = (unsigned long)gtp;
+ goto out;
+ }
+ }
+ }
+ }
+ cb->args[4] = 1;
+out:
+ return skb->len;
+}
+
+static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
+ [GTPA_LINK] = { .type = NLA_U32, },
+ [GTPA_VERSION] = { .type = NLA_U32, },
+ [GTPA_TID] = { .type = NLA_U64, },
+ [GTPA_SGSN_ADDRESS] = { .type = NLA_U32, },
+ [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
+ [GTPA_FLOW] = { .type = NLA_U16, },
+ [GTPA_NET_NS_FD] = { .type = NLA_U32, },
+ [GTPA_I_TEI] = { .type = NLA_U32, },
+ [GTPA_O_TEI] = { .type = NLA_U32, },
+};
+
+static const struct genl_ops gtp_genl_ops[] = {
+ {
+ .cmd = GTP_CMD_NEWPDP,
+ .doit = gtp_genl_new_pdp,
+ .policy = gtp_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = GTP_CMD_DELPDP,
+ .doit = gtp_genl_del_pdp,
+ .policy = gtp_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+ {
+ .cmd = GTP_CMD_GETPDP,
+ .doit = gtp_genl_get_pdp,
+ .dumpit = gtp_genl_dump_pdp,
+ .policy = gtp_genl_policy,
+ .flags = GENL_ADMIN_PERM,
+ },
+};
+
+static int __net_init gtp_net_init(struct net *net)
+{
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+
+ INIT_LIST_HEAD(&gn->gtp_dev_list);
+ return 0;
+}
+
+static void __net_exit gtp_net_exit(struct net *net)
+{
+ struct gtp_net *gn = net_generic(net, gtp_net_id);
+ struct gtp_dev *gtp;
+ LIST_HEAD(list);
+
+ rtnl_lock();
+ list_for_each_entry(gtp, &gn->gtp_dev_list, list)
+ gtp_dellink(gtp->dev, &list);
+
+ unregister_netdevice_many(&list);
+ rtnl_unlock();
+}
+
+static struct pernet_operations gtp_net_ops = {
+ .init = gtp_net_init,
+ .exit = gtp_net_exit,
+ .id = >p_net_id,
+ .size = sizeof(struct gtp_net),
+};
+
+static int __init gtp_init(void)
+{
+ int err;
+
+ get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
+
+ err = rtnl_link_register(>p_link_ops);
+ if (err < 0)
+ goto error_out;
+
+ err = genl_register_family_with_ops(>p_genl_family, gtp_genl_ops);
+ if (err < 0)
+ goto unreg_rtnl_link;
+
+ err = register_pernet_subsys(>p_net_ops);
+ if (err < 0)
+ goto unreg_genl_family;
+
+ pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n",
+ sizeof(struct pdp_ctx));
+ return 0;
+
+unreg_genl_family:
+ genl_unregister_family(>p_genl_family);
+unreg_rtnl_link:
+ rtnl_link_unregister(>p_link_ops);
+error_out:
+ pr_err("error loading GTP module loaded\n");
+ return err;
+}
+late_initcall(gtp_init);
+
+static void __exit gtp_fini(void)
+{
+ unregister_pernet_subsys(>p_net_ops);
+ genl_unregister_family(>p_genl_family);
+ rtnl_link_unregister(>p_link_ops);
+
+ pr_info("GTP module unloaded\n");
+}
+module_exit(gtp_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
+MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
+MODULE_ALIAS_RTNL_LINK("gtp");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff