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;
53 struct in_addr ms_addr_ip4;
54 struct in_addr peer_addr_ip4;
57 struct net_device *dev;
60 struct rcu_head rcu_head;
63 /* One instance of the GTP device. */
65 struct list_head list;
70 struct net_device *dev;
73 unsigned int hash_size;
74 struct hlist_head *tid_hash;
75 struct hlist_head *addr_hash;
78 static unsigned int gtp_net_id __read_mostly;
81 struct list_head gtp_dev_list;
84 static u32 gtp_h_initval;
86 static void pdp_context_delete(struct pdp_ctx *pctx);
88 static inline u32 gtp0_hashfn(u64 tid)
90 u32 *tid32 = (u32 *) &tid;
91 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
94 static inline u32 gtp1u_hashfn(u32 tid)
96 return jhash_1word(tid, gtp_h_initval);
99 static inline u32 ipv4_hashfn(__be32 ip)
101 return jhash_1word((__force u32)ip, gtp_h_initval);
104 /* Resolve a PDP context structure based on the 64bit TID. */
105 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
107 struct hlist_head *head;
110 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
112 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
113 if (pdp->gtp_version == GTP_V0 &&
114 pdp->u.v0.tid == tid)
120 /* Resolve a PDP context structure based on the 32bit TEI. */
121 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
123 struct hlist_head *head;
126 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
128 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
129 if (pdp->gtp_version == GTP_V1 &&
130 pdp->u.v1.i_tei == tid)
136 /* Resolve a PDP context based on IPv4 address of MS. */
137 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
139 struct hlist_head *head;
142 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
144 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
145 if (pdp->af == AF_INET &&
146 pdp->ms_addr_ip4.s_addr == ms_addr)
153 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
154 unsigned int hdrlen, unsigned int role)
158 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
161 iph = (struct iphdr *)(skb->data + hdrlen);
163 if (role == GTP_ROLE_SGSN)
164 return iph->daddr == pctx->ms_addr_ip4.s_addr;
166 return iph->saddr == pctx->ms_addr_ip4.s_addr;
169 /* Check if the inner IP address in this packet is assigned to any
170 * existing mobile subscriber.
172 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
173 unsigned int hdrlen, unsigned int role)
175 switch (ntohs(skb->protocol)) {
177 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
182 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
183 unsigned int hdrlen, unsigned int role)
185 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
186 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
190 /* Get rid of the GTP + UDP headers. */
191 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
192 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
195 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
197 /* Now that the UDP and the GTP header have been removed, set up the
198 * new network header. This is required by the upper layer to
199 * calculate the transport header.
201 skb_reset_network_header(skb);
203 skb->dev = pctx->dev;
205 dev_sw_netstats_rx_add(pctx->dev, skb->len);
211 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
212 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
214 unsigned int hdrlen = sizeof(struct udphdr) +
215 sizeof(struct gtp0_header);
216 struct gtp0_header *gtp0;
217 struct pdp_ctx *pctx;
219 if (!pskb_may_pull(skb, hdrlen))
222 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
224 if ((gtp0->flags >> 5) != GTP_V0)
227 if (gtp0->type != GTP_TPDU)
230 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
232 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
236 return gtp_rx(pctx, skb, hdrlen, gtp->role);
239 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
241 unsigned int hdrlen = sizeof(struct udphdr) +
242 sizeof(struct gtp1_header);
243 struct gtp1_header *gtp1;
244 struct pdp_ctx *pctx;
246 if (!pskb_may_pull(skb, hdrlen))
249 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
251 if ((gtp1->flags >> 5) != GTP_V1)
254 if (gtp1->type != GTP_TPDU)
257 /* From 29.060: "This field shall be present if and only if any one or
258 * more of the S, PN and E flags are set.".
260 * If any of the bit is set, then the remaining ones also have to be
263 if (gtp1->flags & GTP1_F_MASK)
266 /* Make sure the header is larger enough, including extensions. */
267 if (!pskb_may_pull(skb, hdrlen))
270 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
272 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
274 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
278 return gtp_rx(pctx, skb, hdrlen, gtp->role);
281 static void __gtp_encap_destroy(struct sock *sk)
286 gtp = sk->sk_user_data;
292 udp_sk(sk)->encap_type = 0;
293 rcu_assign_sk_user_data(sk, NULL);
301 static void gtp_encap_destroy(struct sock *sk)
304 __gtp_encap_destroy(sk);
308 static void gtp_encap_disable_sock(struct sock *sk)
313 __gtp_encap_destroy(sk);
316 static void gtp_encap_disable(struct gtp_dev *gtp)
318 gtp_encap_disable_sock(gtp->sk0);
319 gtp_encap_disable_sock(gtp->sk1u);
322 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
323 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
325 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
330 gtp = rcu_dereference_sk_user_data(sk);
334 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
336 switch (udp_sk(sk)->encap_type) {
338 netdev_dbg(gtp->dev, "received GTP0 packet\n");
339 ret = gtp0_udp_encap_recv(gtp, skb);
341 case UDP_ENCAP_GTP1U:
342 netdev_dbg(gtp->dev, "received GTP1U packet\n");
343 ret = gtp1u_udp_encap_recv(gtp, skb);
346 ret = -1; /* Shouldn't happen. */
351 netdev_dbg(gtp->dev, "pass up to the process\n");
356 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
365 static int gtp_dev_init(struct net_device *dev)
367 struct gtp_dev *gtp = netdev_priv(dev);
371 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
378 static void gtp_dev_uninit(struct net_device *dev)
380 struct gtp_dev *gtp = netdev_priv(dev);
382 gtp_encap_disable(gtp);
383 free_percpu(dev->tstats);
386 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
387 const struct sock *sk,
390 memset(fl4, 0, sizeof(*fl4));
391 fl4->flowi4_oif = sk->sk_bound_dev_if;
393 fl4->saddr = inet_sk(sk)->inet_saddr;
394 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
395 fl4->flowi4_proto = sk->sk_protocol;
397 return ip_route_output_key(sock_net(sk), fl4);
400 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
402 int payload_len = skb->len;
403 struct gtp0_header *gtp0;
405 gtp0 = skb_push(skb, sizeof(*gtp0));
407 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
408 gtp0->type = GTP_TPDU;
409 gtp0->length = htons(payload_len);
410 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
411 gtp0->flow = htons(pctx->u.v0.flow);
413 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
414 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
417 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
419 int payload_len = skb->len;
420 struct gtp1_header *gtp1;
422 gtp1 = skb_push(skb, sizeof(*gtp1));
424 /* Bits 8 7 6 5 4 3 2 1
425 * +--+--+--+--+--+--+--+--+
426 * |version |PT| 0| E| S|PN|
427 * +--+--+--+--+--+--+--+--+
430 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
431 gtp1->type = GTP_TPDU;
432 gtp1->length = htons(payload_len);
433 gtp1->tid = htonl(pctx->u.v1.o_tei);
435 /* TODO: Suppport for extension header, sequence number and N-PDU.
436 * Update the length field if any of them is available.
445 struct pdp_ctx *pctx;
446 struct net_device *dev;
450 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
452 switch (pktinfo->pctx->gtp_version) {
454 pktinfo->gtph_port = htons(GTP0_PORT);
455 gtp0_push_header(skb, pktinfo->pctx);
458 pktinfo->gtph_port = htons(GTP1U_PORT);
459 gtp1_push_header(skb, pktinfo->pctx);
464 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
465 struct sock *sk, struct iphdr *iph,
466 struct pdp_ctx *pctx, struct rtable *rt,
468 struct net_device *dev)
472 pktinfo->pctx = pctx;
478 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
479 struct gtp_pktinfo *pktinfo)
481 struct gtp_dev *gtp = netdev_priv(dev);
482 struct pdp_ctx *pctx;
489 /* Read the IP destination address and resolve the PDP context.
490 * Prepend PDP header with TEI/TID from PDP ctx.
493 if (gtp->role == GTP_ROLE_SGSN)
494 pctx = ipv4_pdp_find(gtp, iph->saddr);
496 pctx = ipv4_pdp_find(gtp, iph->daddr);
499 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
503 netdev_dbg(dev, "found PDP context %p\n", pctx);
505 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
507 netdev_dbg(dev, "no route to SSGN %pI4\n",
508 &pctx->peer_addr_ip4.s_addr);
509 dev->stats.tx_carrier_errors++;
513 if (rt->dst.dev == dev) {
514 netdev_dbg(dev, "circular route to SSGN %pI4\n",
515 &pctx->peer_addr_ip4.s_addr);
516 dev->stats.collisions++;
522 /* This is similar to tnl_update_pmtu(). */
525 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
526 sizeof(struct iphdr) - sizeof(struct udphdr);
527 switch (pctx->gtp_version) {
529 mtu -= sizeof(struct gtp0_header);
532 mtu -= sizeof(struct gtp1_header);
536 mtu = dst_mtu(&rt->dst);
539 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
541 if (iph->frag_off & htons(IP_DF) &&
542 ((!skb_is_gso(skb) && skb->len > mtu) ||
543 (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
544 netdev_dbg(dev, "packet too big, fragmentation needed\n");
545 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
550 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
551 gtp_push_header(skb, pktinfo);
560 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
562 unsigned int proto = ntohs(skb->protocol);
563 struct gtp_pktinfo pktinfo;
566 /* Ensure there is sufficient headroom. */
567 if (skb_cow_head(skb, dev->needed_headroom))
570 skb_reset_inner_headers(skb);
572 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
576 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
589 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
590 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
591 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
592 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
594 ip4_dst_hoplimit(&pktinfo.rt->dst),
596 pktinfo.gtph_port, pktinfo.gtph_port,
603 dev->stats.tx_errors++;
608 static const struct net_device_ops gtp_netdev_ops = {
609 .ndo_init = gtp_dev_init,
610 .ndo_uninit = gtp_dev_uninit,
611 .ndo_start_xmit = gtp_dev_xmit,
612 .ndo_get_stats64 = ip_tunnel_get_stats64,
615 static void gtp_link_setup(struct net_device *dev)
617 dev->netdev_ops = >p_netdev_ops;
618 dev->needs_free_netdev = true;
620 dev->hard_header_len = 0;
623 /* Zero header length. */
624 dev->type = ARPHRD_NONE;
625 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
627 dev->priv_flags |= IFF_NO_QUEUE;
628 dev->features |= NETIF_F_LLTX;
631 /* Assume largest header, ie. GTPv0. */
632 dev->needed_headroom = LL_MAX_HEADER +
633 sizeof(struct iphdr) +
634 sizeof(struct udphdr) +
635 sizeof(struct gtp0_header);
638 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
639 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
641 static void gtp_destructor(struct net_device *dev)
643 struct gtp_dev *gtp = netdev_priv(dev);
645 kfree(gtp->addr_hash);
646 kfree(gtp->tid_hash);
649 static int gtp_newlink(struct net *src_net, struct net_device *dev,
650 struct nlattr *tb[], struct nlattr *data[],
651 struct netlink_ext_ack *extack)
657 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
660 gtp = netdev_priv(dev);
662 if (!data[IFLA_GTP_PDP_HASHSIZE]) {
665 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
670 err = gtp_hashtable_new(gtp, hashsize);
674 err = gtp_encap_enable(gtp, data);
678 err = register_netdevice(dev);
680 netdev_dbg(dev, "failed to register new netdev %d\n", err);
684 gn = net_generic(dev_net(dev), gtp_net_id);
685 list_add_rcu(>p->list, &gn->gtp_dev_list);
686 dev->priv_destructor = gtp_destructor;
688 netdev_dbg(dev, "registered new GTP interface\n");
693 gtp_encap_disable(gtp);
695 kfree(gtp->addr_hash);
696 kfree(gtp->tid_hash);
700 static void gtp_dellink(struct net_device *dev, struct list_head *head)
702 struct gtp_dev *gtp = netdev_priv(dev);
703 struct pdp_ctx *pctx;
706 for (i = 0; i < gtp->hash_size; i++)
707 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
708 pdp_context_delete(pctx);
710 list_del_rcu(>p->list);
711 unregister_netdevice_queue(dev, head);
714 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
715 [IFLA_GTP_FD0] = { .type = NLA_U32 },
716 [IFLA_GTP_FD1] = { .type = NLA_U32 },
717 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
718 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
721 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
722 struct netlink_ext_ack *extack)
730 static size_t gtp_get_size(const struct net_device *dev)
732 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
735 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
737 struct gtp_dev *gtp = netdev_priv(dev);
739 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
740 goto nla_put_failure;
748 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
750 .maxtype = IFLA_GTP_MAX,
751 .policy = gtp_policy,
752 .priv_size = sizeof(struct gtp_dev),
753 .setup = gtp_link_setup,
754 .validate = gtp_validate,
755 .newlink = gtp_newlink,
756 .dellink = gtp_dellink,
757 .get_size = gtp_get_size,
758 .fill_info = gtp_fill_info,
761 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
765 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
766 GFP_KERNEL | __GFP_NOWARN);
767 if (gtp->addr_hash == NULL)
770 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
771 GFP_KERNEL | __GFP_NOWARN);
772 if (gtp->tid_hash == NULL)
775 gtp->hash_size = hsize;
777 for (i = 0; i < hsize; i++) {
778 INIT_HLIST_HEAD(>p->addr_hash[i]);
779 INIT_HLIST_HEAD(>p->tid_hash[i]);
783 kfree(gtp->addr_hash);
787 static struct sock *gtp_encap_enable_socket(int fd, int type,
790 struct udp_tunnel_sock_cfg tuncfg = {NULL};
795 pr_debug("enable gtp on %d, %d\n", fd, type);
797 sock = sockfd_lookup(fd, &err);
799 pr_debug("gtp socket fd=%d not found\n", fd);
804 if (sk->sk_protocol != IPPROTO_UDP ||
805 sk->sk_type != SOCK_DGRAM ||
806 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
807 pr_debug("socket fd=%d not UDP\n", fd);
808 sk = ERR_PTR(-EINVAL);
813 if (sk->sk_user_data) {
814 sk = ERR_PTR(-EBUSY);
820 tuncfg.sk_user_data = gtp;
821 tuncfg.encap_type = type;
822 tuncfg.encap_rcv = gtp_encap_recv;
823 tuncfg.encap_destroy = gtp_encap_destroy;
825 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
828 release_sock(sock->sk);
834 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
836 struct sock *sk1u = NULL;
837 struct sock *sk0 = NULL;
838 unsigned int role = GTP_ROLE_GGSN;
840 if (data[IFLA_GTP_FD0]) {
841 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
843 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
848 if (data[IFLA_GTP_FD1]) {
849 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
851 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
853 gtp_encap_disable_sock(sk0);
854 return PTR_ERR(sk1u);
858 if (data[IFLA_GTP_ROLE]) {
859 role = nla_get_u32(data[IFLA_GTP_ROLE]);
860 if (role > GTP_ROLE_SGSN) {
861 gtp_encap_disable_sock(sk0);
862 gtp_encap_disable_sock(sk1u);
874 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
876 struct gtp_dev *gtp = NULL;
877 struct net_device *dev;
880 /* Examine the link attributes and figure out which network namespace
881 * we are talking about.
883 if (nla[GTPA_NET_NS_FD])
884 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
886 net = get_net(src_net);
891 /* Check if there's an existing gtpX device to configure */
892 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
893 if (dev && dev->netdev_ops == >p_netdev_ops)
894 gtp = netdev_priv(dev);
900 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
902 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
904 pctx->peer_addr_ip4.s_addr =
905 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
906 pctx->ms_addr_ip4.s_addr =
907 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
909 switch (pctx->gtp_version) {
911 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
912 * label needs to be the same for uplink and downlink packets,
913 * so let's annotate this.
915 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
916 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
919 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
920 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
927 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
928 struct genl_info *info)
930 struct pdp_ctx *pctx, *pctx_tid = NULL;
931 struct net_device *dev = gtp->dev;
932 u32 hash_ms, hash_tid = 0;
933 unsigned int version;
937 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
938 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
939 version = nla_get_u32(info->attrs[GTPA_VERSION]);
941 pctx = ipv4_pdp_find(gtp, ms_addr);
944 if (version == GTP_V0)
945 pctx_tid = gtp0_pdp_find(gtp,
946 nla_get_u64(info->attrs[GTPA_TID]));
947 else if (version == GTP_V1)
948 pctx_tid = gtp1_pdp_find(gtp,
949 nla_get_u32(info->attrs[GTPA_I_TEI]));
954 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
955 return ERR_PTR(-EEXIST);
956 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
957 return ERR_PTR(-EOPNOTSUPP);
959 if (pctx && pctx_tid)
960 return ERR_PTR(-EEXIST);
964 ipv4_pdp_fill(pctx, info);
966 if (pctx->gtp_version == GTP_V0)
967 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
968 pctx->u.v0.tid, pctx);
969 else if (pctx->gtp_version == GTP_V1)
970 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
971 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
977 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
979 return ERR_PTR(-ENOMEM);
983 pctx->dev = gtp->dev;
984 ipv4_pdp_fill(pctx, info);
985 atomic_set(&pctx->tx_seq, 0);
987 switch (pctx->gtp_version) {
989 /* TS 09.60: "The flow label identifies unambiguously a GTP
990 * flow.". We use the tid for this instead, I cannot find a
991 * situation in which this doesn't unambiguosly identify the
994 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
997 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1001 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
1002 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1004 switch (pctx->gtp_version) {
1006 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1007 pctx->u.v0.tid, &pctx->peer_addr_ip4,
1008 &pctx->ms_addr_ip4, pctx);
1011 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1012 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1013 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1020 static void pdp_context_free(struct rcu_head *head)
1022 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1028 static void pdp_context_delete(struct pdp_ctx *pctx)
1030 hlist_del_rcu(&pctx->hlist_tid);
1031 hlist_del_rcu(&pctx->hlist_addr);
1032 call_rcu(&pctx->rcu_head, pdp_context_free);
1035 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1037 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1039 unsigned int version;
1040 struct pdp_ctx *pctx;
1041 struct gtp_dev *gtp;
1045 if (!info->attrs[GTPA_VERSION] ||
1046 !info->attrs[GTPA_LINK] ||
1047 !info->attrs[GTPA_PEER_ADDRESS] ||
1048 !info->attrs[GTPA_MS_ADDRESS])
1051 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1055 if (!info->attrs[GTPA_TID] ||
1056 !info->attrs[GTPA_FLOW])
1060 if (!info->attrs[GTPA_I_TEI] ||
1061 !info->attrs[GTPA_O_TEI])
1071 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1077 if (version == GTP_V0)
1079 else if (version == GTP_V1)
1089 pctx = gtp_pdp_add(gtp, sk, info);
1091 err = PTR_ERR(pctx);
1093 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1102 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1103 struct nlattr *nla[])
1105 struct gtp_dev *gtp;
1107 gtp = gtp_find_dev(net, nla);
1109 return ERR_PTR(-ENODEV);
1111 if (nla[GTPA_MS_ADDRESS]) {
1112 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1114 return ipv4_pdp_find(gtp, ip);
1115 } else if (nla[GTPA_VERSION]) {
1116 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1118 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1119 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1120 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1121 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1124 return ERR_PTR(-EINVAL);
1127 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1129 struct pdp_ctx *pctx;
1132 pctx = gtp_find_pdp_by_link(net, nla);
1134 pctx = ERR_PTR(-EINVAL);
1137 pctx = ERR_PTR(-ENOENT);
1142 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1144 struct pdp_ctx *pctx;
1147 if (!info->attrs[GTPA_VERSION])
1152 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1154 err = PTR_ERR(pctx);
1158 if (pctx->gtp_version == GTP_V0)
1159 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1160 pctx->u.v0.tid, pctx);
1161 else if (pctx->gtp_version == GTP_V1)
1162 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1163 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1165 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1166 pdp_context_delete(pctx);
1173 static struct genl_family gtp_genl_family;
1175 enum gtp_multicast_groups {
1179 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
1180 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
1183 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1184 int flags, u32 type, struct pdp_ctx *pctx)
1188 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
1193 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1194 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1195 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1196 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1197 goto nla_put_failure;
1199 switch (pctx->gtp_version) {
1201 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1202 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1203 goto nla_put_failure;
1206 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1207 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1208 goto nla_put_failure;
1211 genlmsg_end(skb, genlh);
1216 genlmsg_cancel(skb, genlh);
1220 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1222 struct sk_buff *msg;
1225 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1229 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1235 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg,
1236 0, GTP_GENL_MCGRP, GFP_ATOMIC);
1240 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1242 struct pdp_ctx *pctx = NULL;
1243 struct sk_buff *skb2;
1246 if (!info->attrs[GTPA_VERSION])
1251 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1253 err = PTR_ERR(pctx);
1257 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1263 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1264 0, info->nlhdr->nlmsg_type, pctx);
1266 goto err_unlock_free;
1269 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1278 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1279 struct netlink_callback *cb)
1281 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1282 int i, j, bucket = cb->args[0], skip = cb->args[1];
1283 struct net *net = sock_net(skb->sk);
1284 struct pdp_ctx *pctx;
1287 gn = net_generic(net, gtp_net_id);
1293 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1294 if (last_gtp && last_gtp != gtp)
1299 for (i = bucket; i < gtp->hash_size; i++) {
1301 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
1304 gtp_genl_fill_info(skb,
1305 NETLINK_CB(cb->skb).portid,
1308 cb->nlh->nlmsg_type, pctx)) {
1311 cb->args[2] = (unsigned long)gtp;
1326 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1327 [GTPA_LINK] = { .type = NLA_U32, },
1328 [GTPA_VERSION] = { .type = NLA_U32, },
1329 [GTPA_TID] = { .type = NLA_U64, },
1330 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1331 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1332 [GTPA_FLOW] = { .type = NLA_U16, },
1333 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1334 [GTPA_I_TEI] = { .type = NLA_U32, },
1335 [GTPA_O_TEI] = { .type = NLA_U32, },
1338 static const struct genl_small_ops gtp_genl_ops[] = {
1340 .cmd = GTP_CMD_NEWPDP,
1341 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1342 .doit = gtp_genl_new_pdp,
1343 .flags = GENL_ADMIN_PERM,
1346 .cmd = GTP_CMD_DELPDP,
1347 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1348 .doit = gtp_genl_del_pdp,
1349 .flags = GENL_ADMIN_PERM,
1352 .cmd = GTP_CMD_GETPDP,
1353 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1354 .doit = gtp_genl_get_pdp,
1355 .dumpit = gtp_genl_dump_pdp,
1356 .flags = GENL_ADMIN_PERM,
1360 static struct genl_family gtp_genl_family __ro_after_init = {
1364 .maxattr = GTPA_MAX,
1365 .policy = gtp_genl_policy,
1367 .module = THIS_MODULE,
1368 .small_ops = gtp_genl_ops,
1369 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
1370 .mcgrps = gtp_genl_mcgrps,
1371 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
1374 static int __net_init gtp_net_init(struct net *net)
1376 struct gtp_net *gn = net_generic(net, gtp_net_id);
1378 INIT_LIST_HEAD(&gn->gtp_dev_list);
1382 static void __net_exit gtp_net_exit(struct net *net)
1384 struct gtp_net *gn = net_generic(net, gtp_net_id);
1385 struct gtp_dev *gtp;
1389 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1390 gtp_dellink(gtp->dev, &list);
1392 unregister_netdevice_many(&list);
1396 static struct pernet_operations gtp_net_ops = {
1397 .init = gtp_net_init,
1398 .exit = gtp_net_exit,
1400 .size = sizeof(struct gtp_net),
1403 static int __init gtp_init(void)
1407 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1409 err = register_pernet_subsys(>p_net_ops);
1413 err = rtnl_link_register(>p_link_ops);
1415 goto unreg_pernet_subsys;
1417 err = genl_register_family(>p_genl_family);
1419 goto unreg_rtnl_link;
1421 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1422 sizeof(struct pdp_ctx));
1426 rtnl_link_unregister(>p_link_ops);
1427 unreg_pernet_subsys:
1428 unregister_pernet_subsys(>p_net_ops);
1430 pr_err("error loading GTP module loaded\n");
1433 late_initcall(gtp_init);
1435 static void __exit gtp_fini(void)
1437 genl_unregister_family(>p_genl_family);
1438 rtnl_link_unregister(>p_link_ops);
1439 unregister_pernet_subsys(>p_net_ops);
1441 pr_info("GTP module unloaded\n");
1443 module_exit(gtp_fini);
1445 MODULE_LICENSE("GPL");
1446 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1447 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1448 MODULE_ALIAS_RTNL_LINK("gtp");
1449 MODULE_ALIAS_GENL_FAMILY("gtp");