1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060
4 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
5 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
7 * Author: Harald Welte <hwelte@sysmocom.de>
8 * Pablo Neira Ayuso <pablo@netfilter.org>
9 * Andreas Schultz <aschultz@travelping.com>
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/udp.h>
17 #include <linux/rculist.h>
18 #include <linux/jhash.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/net.h>
21 #include <linux/file.h>
22 #include <linux/gtp.h>
24 #include <net/net_namespace.h>
25 #include <net/protocol.h>
28 #include <net/udp_tunnel.h>
31 #include <net/genetlink.h>
32 #include <net/netns/generic.h>
35 /* An active session for the subscriber. */
37 struct hlist_node hlist_tid;
38 struct hlist_node hlist_addr;
54 struct in_addr ms_addr_ip4;
55 struct in_addr peer_addr_ip4;
58 struct net_device *dev;
61 struct rcu_head rcu_head;
64 /* One instance of the GTP device. */
66 struct list_head list;
71 struct net_device *dev;
74 unsigned int hash_size;
75 struct hlist_head *tid_hash;
76 struct hlist_head *addr_hash;
79 static unsigned int gtp_net_id __read_mostly;
82 struct list_head gtp_dev_list;
85 static u32 gtp_h_initval;
87 static void pdp_context_delete(struct pdp_ctx *pctx);
89 static inline u32 gtp0_hashfn(u64 tid)
91 u32 *tid32 = (u32 *) &tid;
92 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
95 static inline u32 gtp1u_hashfn(u32 tid)
97 return jhash_1word(tid, gtp_h_initval);
100 static inline u32 ipv4_hashfn(__be32 ip)
102 return jhash_1word((__force u32)ip, gtp_h_initval);
105 /* Resolve a PDP context structure based on the 64bit TID. */
106 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
108 struct hlist_head *head;
111 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
113 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
114 if (pdp->gtp_version == GTP_V0 &&
115 pdp->u.v0.tid == tid)
121 /* Resolve a PDP context structure based on the 32bit TEI. */
122 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
124 struct hlist_head *head;
127 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
129 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
130 if (pdp->gtp_version == GTP_V1 &&
131 pdp->u.v1.i_tei == tid)
137 /* Resolve a PDP context based on IPv4 address of MS. */
138 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
140 struct hlist_head *head;
143 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
145 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
146 if (pdp->af == AF_INET &&
147 pdp->ms_addr_ip4.s_addr == ms_addr)
154 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
155 unsigned int hdrlen, unsigned int role)
159 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
162 iph = (struct iphdr *)(skb->data + hdrlen);
164 if (role == GTP_ROLE_SGSN)
165 return iph->daddr == pctx->ms_addr_ip4.s_addr;
167 return iph->saddr == pctx->ms_addr_ip4.s_addr;
170 /* Check if the inner IP address in this packet is assigned to any
171 * existing mobile subscriber.
173 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
174 unsigned int hdrlen, unsigned int role)
176 switch (ntohs(skb->protocol)) {
178 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
183 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
184 unsigned int hdrlen, unsigned int role)
186 struct pcpu_sw_netstats *stats;
188 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
189 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
193 /* Get rid of the GTP + UDP headers. */
194 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
195 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
198 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
200 /* Now that the UDP and the GTP header have been removed, set up the
201 * new network header. This is required by the upper layer to
202 * calculate the transport header.
204 skb_reset_network_header(skb);
206 skb->dev = pctx->dev;
208 stats = this_cpu_ptr(pctx->dev->tstats);
209 u64_stats_update_begin(&stats->syncp);
211 stats->rx_bytes += skb->len;
212 u64_stats_update_end(&stats->syncp);
218 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
219 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
221 unsigned int hdrlen = sizeof(struct udphdr) +
222 sizeof(struct gtp0_header);
223 struct gtp0_header *gtp0;
224 struct pdp_ctx *pctx;
226 if (!pskb_may_pull(skb, hdrlen))
229 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
231 if ((gtp0->flags >> 5) != GTP_V0)
234 if (gtp0->type != GTP_TPDU)
237 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
239 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
243 return gtp_rx(pctx, skb, hdrlen, gtp->role);
246 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
248 unsigned int hdrlen = sizeof(struct udphdr) +
249 sizeof(struct gtp1_header);
250 struct gtp1_header *gtp1;
251 struct pdp_ctx *pctx;
253 if (!pskb_may_pull(skb, hdrlen))
256 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
258 if ((gtp1->flags >> 5) != GTP_V1)
261 if (gtp1->type != GTP_TPDU)
264 /* From 29.060: "This field shall be present if and only if any one or
265 * more of the S, PN and E flags are set.".
267 * If any of the bit is set, then the remaining ones also have to be
270 if (gtp1->flags & GTP1_F_MASK)
273 /* Make sure the header is larger enough, including extensions. */
274 if (!pskb_may_pull(skb, hdrlen))
277 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
279 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
281 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
285 return gtp_rx(pctx, skb, hdrlen, gtp->role);
288 static void gtp_encap_destroy(struct sock *sk)
293 gtp = sk->sk_user_data;
295 udp_sk(sk)->encap_type = 0;
296 rcu_assign_sk_user_data(sk, NULL);
302 static void gtp_encap_disable_sock(struct sock *sk)
307 gtp_encap_destroy(sk);
310 static void gtp_encap_disable(struct gtp_dev *gtp)
312 gtp_encap_disable_sock(gtp->sk0);
313 gtp_encap_disable_sock(gtp->sk1u);
316 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
317 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
319 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
324 gtp = rcu_dereference_sk_user_data(sk);
328 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
330 switch (udp_sk(sk)->encap_type) {
332 netdev_dbg(gtp->dev, "received GTP0 packet\n");
333 ret = gtp0_udp_encap_recv(gtp, skb);
335 case UDP_ENCAP_GTP1U:
336 netdev_dbg(gtp->dev, "received GTP1U packet\n");
337 ret = gtp1u_udp_encap_recv(gtp, skb);
340 ret = -1; /* Shouldn't happen. */
345 netdev_dbg(gtp->dev, "pass up to the process\n");
350 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
359 static int gtp_dev_init(struct net_device *dev)
361 struct gtp_dev *gtp = netdev_priv(dev);
365 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
372 static void gtp_dev_uninit(struct net_device *dev)
374 struct gtp_dev *gtp = netdev_priv(dev);
376 gtp_encap_disable(gtp);
377 free_percpu(dev->tstats);
380 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
381 const struct sock *sk,
384 memset(fl4, 0, sizeof(*fl4));
385 fl4->flowi4_oif = sk->sk_bound_dev_if;
387 fl4->saddr = inet_sk(sk)->inet_saddr;
388 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
389 fl4->flowi4_proto = sk->sk_protocol;
391 return ip_route_output_key(sock_net(sk), fl4);
394 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
396 int payload_len = skb->len;
397 struct gtp0_header *gtp0;
399 gtp0 = skb_push(skb, sizeof(*gtp0));
401 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
402 gtp0->type = GTP_TPDU;
403 gtp0->length = htons(payload_len);
404 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
405 gtp0->flow = htons(pctx->u.v0.flow);
407 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
408 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
411 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
413 int payload_len = skb->len;
414 struct gtp1_header *gtp1;
416 gtp1 = skb_push(skb, sizeof(*gtp1));
418 /* Bits 8 7 6 5 4 3 2 1
419 * +--+--+--+--+--+--+--+--+
420 * |version |PT| 0| E| S|PN|
421 * +--+--+--+--+--+--+--+--+
424 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
425 gtp1->type = GTP_TPDU;
426 gtp1->length = htons(payload_len);
427 gtp1->tid = htonl(pctx->u.v1.o_tei);
429 /* TODO: Suppport for extension header, sequence number and N-PDU.
430 * Update the length field if any of them is available.
439 struct pdp_ctx *pctx;
440 struct net_device *dev;
444 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
446 switch (pktinfo->pctx->gtp_version) {
448 pktinfo->gtph_port = htons(GTP0_PORT);
449 gtp0_push_header(skb, pktinfo->pctx);
452 pktinfo->gtph_port = htons(GTP1U_PORT);
453 gtp1_push_header(skb, pktinfo->pctx);
458 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
459 struct sock *sk, struct iphdr *iph,
460 struct pdp_ctx *pctx, struct rtable *rt,
462 struct net_device *dev)
466 pktinfo->pctx = pctx;
472 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
473 struct gtp_pktinfo *pktinfo)
475 struct gtp_dev *gtp = netdev_priv(dev);
476 struct pdp_ctx *pctx;
483 /* Read the IP destination address and resolve the PDP context.
484 * Prepend PDP header with TEI/TID from PDP ctx.
487 if (gtp->role == GTP_ROLE_SGSN)
488 pctx = ipv4_pdp_find(gtp, iph->saddr);
490 pctx = ipv4_pdp_find(gtp, iph->daddr);
493 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
497 netdev_dbg(dev, "found PDP context %p\n", pctx);
499 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
501 netdev_dbg(dev, "no route to SSGN %pI4\n",
502 &pctx->peer_addr_ip4.s_addr);
503 dev->stats.tx_carrier_errors++;
507 if (rt->dst.dev == dev) {
508 netdev_dbg(dev, "circular route to SSGN %pI4\n",
509 &pctx->peer_addr_ip4.s_addr);
510 dev->stats.collisions++;
516 /* This is similar to tnl_update_pmtu(). */
519 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
520 sizeof(struct iphdr) - sizeof(struct udphdr);
521 switch (pctx->gtp_version) {
523 mtu -= sizeof(struct gtp0_header);
526 mtu -= sizeof(struct gtp1_header);
530 mtu = dst_mtu(&rt->dst);
533 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
535 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
536 mtu < ntohs(iph->tot_len)) {
537 netdev_dbg(dev, "packet too big, fragmentation needed\n");
538 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
539 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
544 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
545 gtp_push_header(skb, pktinfo);
554 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
556 unsigned int proto = ntohs(skb->protocol);
557 struct gtp_pktinfo pktinfo;
560 /* Ensure there is sufficient headroom. */
561 if (skb_cow_head(skb, dev->needed_headroom))
564 skb_reset_inner_headers(skb);
566 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
570 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
583 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
584 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
585 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
586 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
588 ip4_dst_hoplimit(&pktinfo.rt->dst),
590 pktinfo.gtph_port, pktinfo.gtph_port,
597 dev->stats.tx_errors++;
602 static const struct net_device_ops gtp_netdev_ops = {
603 .ndo_init = gtp_dev_init,
604 .ndo_uninit = gtp_dev_uninit,
605 .ndo_start_xmit = gtp_dev_xmit,
606 .ndo_get_stats64 = ip_tunnel_get_stats64,
609 static void gtp_link_setup(struct net_device *dev)
611 dev->netdev_ops = >p_netdev_ops;
612 dev->needs_free_netdev = true;
614 dev->hard_header_len = 0;
617 /* Zero header length. */
618 dev->type = ARPHRD_NONE;
619 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
621 dev->priv_flags |= IFF_NO_QUEUE;
622 dev->features |= NETIF_F_LLTX;
625 /* Assume largest header, ie. GTPv0. */
626 dev->needed_headroom = LL_MAX_HEADER +
627 sizeof(struct iphdr) +
628 sizeof(struct udphdr) +
629 sizeof(struct gtp0_header);
632 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
633 static void gtp_hashtable_free(struct gtp_dev *gtp);
634 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
636 static int gtp_newlink(struct net *src_net, struct net_device *dev,
637 struct nlattr *tb[], struct nlattr *data[],
638 struct netlink_ext_ack *extack)
644 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
647 gtp = netdev_priv(dev);
649 err = gtp_encap_enable(gtp, data);
653 if (!data[IFLA_GTP_PDP_HASHSIZE])
656 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
658 err = gtp_hashtable_new(gtp, hashsize);
662 err = register_netdevice(dev);
664 netdev_dbg(dev, "failed to register new netdev %d\n", err);
668 gn = net_generic(dev_net(dev), gtp_net_id);
669 list_add_rcu(>p->list, &gn->gtp_dev_list);
671 netdev_dbg(dev, "registered new GTP interface\n");
676 gtp_hashtable_free(gtp);
678 gtp_encap_disable(gtp);
682 static void gtp_dellink(struct net_device *dev, struct list_head *head)
684 struct gtp_dev *gtp = netdev_priv(dev);
686 gtp_encap_disable(gtp);
687 gtp_hashtable_free(gtp);
688 list_del_rcu(>p->list);
689 unregister_netdevice_queue(dev, head);
692 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
693 [IFLA_GTP_FD0] = { .type = NLA_U32 },
694 [IFLA_GTP_FD1] = { .type = NLA_U32 },
695 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
696 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
699 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
700 struct netlink_ext_ack *extack)
708 static size_t gtp_get_size(const struct net_device *dev)
710 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
713 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
715 struct gtp_dev *gtp = netdev_priv(dev);
717 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
718 goto nla_put_failure;
726 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
728 .maxtype = IFLA_GTP_MAX,
729 .policy = gtp_policy,
730 .priv_size = sizeof(struct gtp_dev),
731 .setup = gtp_link_setup,
732 .validate = gtp_validate,
733 .newlink = gtp_newlink,
734 .dellink = gtp_dellink,
735 .get_size = gtp_get_size,
736 .fill_info = gtp_fill_info,
739 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
743 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
745 if (gtp->addr_hash == NULL)
748 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
750 if (gtp->tid_hash == NULL)
753 gtp->hash_size = hsize;
755 for (i = 0; i < hsize; i++) {
756 INIT_HLIST_HEAD(>p->addr_hash[i]);
757 INIT_HLIST_HEAD(>p->tid_hash[i]);
761 kfree(gtp->addr_hash);
765 static void gtp_hashtable_free(struct gtp_dev *gtp)
767 struct pdp_ctx *pctx;
770 for (i = 0; i < gtp->hash_size; i++)
771 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
772 pdp_context_delete(pctx);
775 kfree(gtp->addr_hash);
776 kfree(gtp->tid_hash);
779 static struct sock *gtp_encap_enable_socket(int fd, int type,
782 struct udp_tunnel_sock_cfg tuncfg = {NULL};
787 pr_debug("enable gtp on %d, %d\n", fd, type);
789 sock = sockfd_lookup(fd, &err);
791 pr_debug("gtp socket fd=%d not found\n", fd);
795 if (sock->sk->sk_protocol != IPPROTO_UDP) {
796 pr_debug("socket fd=%d not UDP\n", fd);
797 sk = ERR_PTR(-EINVAL);
802 if (sock->sk->sk_user_data) {
803 sk = ERR_PTR(-EBUSY);
810 tuncfg.sk_user_data = gtp;
811 tuncfg.encap_type = type;
812 tuncfg.encap_rcv = gtp_encap_recv;
813 tuncfg.encap_destroy = gtp_encap_destroy;
815 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
818 release_sock(sock->sk);
823 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
825 struct sock *sk1u = NULL;
826 struct sock *sk0 = NULL;
827 unsigned int role = GTP_ROLE_GGSN;
829 if (data[IFLA_GTP_FD0]) {
830 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
832 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
837 if (data[IFLA_GTP_FD1]) {
838 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
840 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
843 gtp_encap_disable_sock(sk0);
844 return PTR_ERR(sk1u);
848 if (data[IFLA_GTP_ROLE]) {
849 role = nla_get_u32(data[IFLA_GTP_ROLE]);
850 if (role > GTP_ROLE_SGSN)
861 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
863 struct gtp_dev *gtp = NULL;
864 struct net_device *dev;
867 /* Examine the link attributes and figure out which network namespace
868 * we are talking about.
870 if (nla[GTPA_NET_NS_FD])
871 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
873 net = get_net(src_net);
878 /* Check if there's an existing gtpX device to configure */
879 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
880 if (dev && dev->netdev_ops == >p_netdev_ops)
881 gtp = netdev_priv(dev);
887 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
889 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
891 pctx->peer_addr_ip4.s_addr =
892 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
893 pctx->ms_addr_ip4.s_addr =
894 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
896 switch (pctx->gtp_version) {
898 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
899 * label needs to be the same for uplink and downlink packets,
900 * so let's annotate this.
902 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
903 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
906 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
907 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
914 static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
915 struct genl_info *info)
917 struct net_device *dev = gtp->dev;
918 u32 hash_ms, hash_tid = 0;
919 struct pdp_ctx *pctx;
923 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
924 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
926 hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) {
927 if (pctx->ms_addr_ip4.s_addr == ms_addr) {
934 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
936 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
939 ipv4_pdp_fill(pctx, info);
941 if (pctx->gtp_version == GTP_V0)
942 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
943 pctx->u.v0.tid, pctx);
944 else if (pctx->gtp_version == GTP_V1)
945 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
946 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
952 pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
958 pctx->dev = gtp->dev;
959 ipv4_pdp_fill(pctx, info);
960 atomic_set(&pctx->tx_seq, 0);
962 switch (pctx->gtp_version) {
964 /* TS 09.60: "The flow label identifies unambiguously a GTP
965 * flow.". We use the tid for this instead, I cannot find a
966 * situation in which this doesn't unambiguosly identify the
969 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
972 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
976 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
977 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
979 switch (pctx->gtp_version) {
981 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
982 pctx->u.v0.tid, &pctx->peer_addr_ip4,
983 &pctx->ms_addr_ip4, pctx);
986 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
987 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
988 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
995 static void pdp_context_free(struct rcu_head *head)
997 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1003 static void pdp_context_delete(struct pdp_ctx *pctx)
1005 hlist_del_rcu(&pctx->hlist_tid);
1006 hlist_del_rcu(&pctx->hlist_addr);
1007 call_rcu(&pctx->rcu_head, pdp_context_free);
1010 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1012 unsigned int version;
1013 struct gtp_dev *gtp;
1017 if (!info->attrs[GTPA_VERSION] ||
1018 !info->attrs[GTPA_LINK] ||
1019 !info->attrs[GTPA_PEER_ADDRESS] ||
1020 !info->attrs[GTPA_MS_ADDRESS])
1023 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1027 if (!info->attrs[GTPA_TID] ||
1028 !info->attrs[GTPA_FLOW])
1032 if (!info->attrs[GTPA_I_TEI] ||
1033 !info->attrs[GTPA_O_TEI])
1043 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1049 if (version == GTP_V0)
1051 else if (version == GTP_V1)
1061 err = ipv4_pdp_add(gtp, sk, info);
1068 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1069 struct nlattr *nla[])
1071 struct gtp_dev *gtp;
1073 gtp = gtp_find_dev(net, nla);
1075 return ERR_PTR(-ENODEV);
1077 if (nla[GTPA_MS_ADDRESS]) {
1078 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1080 return ipv4_pdp_find(gtp, ip);
1081 } else if (nla[GTPA_VERSION]) {
1082 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1084 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1085 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1086 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1087 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1090 return ERR_PTR(-EINVAL);
1093 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1095 struct pdp_ctx *pctx;
1098 pctx = gtp_find_pdp_by_link(net, nla);
1100 pctx = ERR_PTR(-EINVAL);
1103 pctx = ERR_PTR(-ENOENT);
1108 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1110 struct pdp_ctx *pctx;
1113 if (!info->attrs[GTPA_VERSION])
1118 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1120 err = PTR_ERR(pctx);
1124 if (pctx->gtp_version == GTP_V0)
1125 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1126 pctx->u.v0.tid, pctx);
1127 else if (pctx->gtp_version == GTP_V1)
1128 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1129 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1131 pdp_context_delete(pctx);
1138 static struct genl_family gtp_genl_family;
1140 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1141 u32 type, struct pdp_ctx *pctx)
1145 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0,
1150 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1151 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1152 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1153 goto nla_put_failure;
1155 switch (pctx->gtp_version) {
1157 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1158 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1159 goto nla_put_failure;
1162 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1163 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1164 goto nla_put_failure;
1167 genlmsg_end(skb, genlh);
1172 genlmsg_cancel(skb, genlh);
1176 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1178 struct pdp_ctx *pctx = NULL;
1179 struct sk_buff *skb2;
1182 if (!info->attrs[GTPA_VERSION])
1187 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1189 err = PTR_ERR(pctx);
1193 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1199 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1200 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1202 goto err_unlock_free;
1205 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1214 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1215 struct netlink_callback *cb)
1217 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1218 struct net *net = sock_net(skb->sk);
1219 struct gtp_net *gn = net_generic(net, gtp_net_id);
1220 unsigned long tid = cb->args[1];
1221 int i, k = cb->args[0], ret;
1222 struct pdp_ctx *pctx;
1227 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1228 if (last_gtp && last_gtp != gtp)
1233 for (i = k; i < gtp->hash_size; i++) {
1234 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
1235 if (tid && tid != pctx->u.tid)
1240 ret = gtp_genl_fill_info(skb,
1241 NETLINK_CB(cb->skb).portid,
1243 cb->nlh->nlmsg_type, pctx);
1246 cb->args[1] = pctx->u.tid;
1247 cb->args[2] = (unsigned long)gtp;
1258 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1259 [GTPA_LINK] = { .type = NLA_U32, },
1260 [GTPA_VERSION] = { .type = NLA_U32, },
1261 [GTPA_TID] = { .type = NLA_U64, },
1262 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1263 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1264 [GTPA_FLOW] = { .type = NLA_U16, },
1265 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1266 [GTPA_I_TEI] = { .type = NLA_U32, },
1267 [GTPA_O_TEI] = { .type = NLA_U32, },
1270 static const struct genl_ops gtp_genl_ops[] = {
1272 .cmd = GTP_CMD_NEWPDP,
1273 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1274 .doit = gtp_genl_new_pdp,
1275 .flags = GENL_ADMIN_PERM,
1278 .cmd = GTP_CMD_DELPDP,
1279 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1280 .doit = gtp_genl_del_pdp,
1281 .flags = GENL_ADMIN_PERM,
1284 .cmd = GTP_CMD_GETPDP,
1285 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1286 .doit = gtp_genl_get_pdp,
1287 .dumpit = gtp_genl_dump_pdp,
1288 .flags = GENL_ADMIN_PERM,
1292 static struct genl_family gtp_genl_family __ro_after_init = {
1296 .maxattr = GTPA_MAX,
1297 .policy = gtp_genl_policy,
1299 .module = THIS_MODULE,
1300 .ops = gtp_genl_ops,
1301 .n_ops = ARRAY_SIZE(gtp_genl_ops),
1304 static int __net_init gtp_net_init(struct net *net)
1306 struct gtp_net *gn = net_generic(net, gtp_net_id);
1308 INIT_LIST_HEAD(&gn->gtp_dev_list);
1312 static void __net_exit gtp_net_exit(struct net *net)
1314 struct gtp_net *gn = net_generic(net, gtp_net_id);
1315 struct gtp_dev *gtp;
1319 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1320 gtp_dellink(gtp->dev, &list);
1322 unregister_netdevice_many(&list);
1326 static struct pernet_operations gtp_net_ops = {
1327 .init = gtp_net_init,
1328 .exit = gtp_net_exit,
1330 .size = sizeof(struct gtp_net),
1333 static int __init gtp_init(void)
1337 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1339 err = rtnl_link_register(>p_link_ops);
1343 err = genl_register_family(>p_genl_family);
1345 goto unreg_rtnl_link;
1347 err = register_pernet_subsys(>p_net_ops);
1349 goto unreg_genl_family;
1351 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1352 sizeof(struct pdp_ctx));
1356 genl_unregister_family(>p_genl_family);
1358 rtnl_link_unregister(>p_link_ops);
1360 pr_err("error loading GTP module loaded\n");
1363 late_initcall(gtp_init);
1365 static void __exit gtp_fini(void)
1367 unregister_pernet_subsys(>p_net_ops);
1368 genl_unregister_family(>p_genl_family);
1369 rtnl_link_unregister(>p_link_ops);
1371 pr_info("GTP module unloaded\n");
1373 module_exit(gtp_fini);
1375 MODULE_LICENSE("GPL");
1376 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1377 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1378 MODULE_ALIAS_RTNL_LINK("gtp");
1379 MODULE_ALIAS_GENL_FAMILY("gtp");