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;
299 udp_sk(sk)->encap_type = 0;
300 rcu_assign_sk_user_data(sk, NULL);
306 static void gtp_encap_destroy(struct sock *sk)
309 __gtp_encap_destroy(sk);
313 static void gtp_encap_disable_sock(struct sock *sk)
318 __gtp_encap_destroy(sk);
321 static void gtp_encap_disable(struct gtp_dev *gtp)
323 gtp_encap_disable_sock(gtp->sk0);
324 gtp_encap_disable_sock(gtp->sk1u);
327 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
328 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
330 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
335 gtp = rcu_dereference_sk_user_data(sk);
339 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
341 switch (udp_sk(sk)->encap_type) {
343 netdev_dbg(gtp->dev, "received GTP0 packet\n");
344 ret = gtp0_udp_encap_recv(gtp, skb);
346 case UDP_ENCAP_GTP1U:
347 netdev_dbg(gtp->dev, "received GTP1U packet\n");
348 ret = gtp1u_udp_encap_recv(gtp, skb);
351 ret = -1; /* Shouldn't happen. */
356 netdev_dbg(gtp->dev, "pass up to the process\n");
361 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
370 static int gtp_dev_init(struct net_device *dev)
372 struct gtp_dev *gtp = netdev_priv(dev);
376 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
383 static void gtp_dev_uninit(struct net_device *dev)
385 struct gtp_dev *gtp = netdev_priv(dev);
387 gtp_encap_disable(gtp);
388 free_percpu(dev->tstats);
391 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
392 const struct sock *sk,
395 memset(fl4, 0, sizeof(*fl4));
396 fl4->flowi4_oif = sk->sk_bound_dev_if;
398 fl4->saddr = inet_sk(sk)->inet_saddr;
399 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
400 fl4->flowi4_proto = sk->sk_protocol;
402 return ip_route_output_key(sock_net(sk), fl4);
405 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
407 int payload_len = skb->len;
408 struct gtp0_header *gtp0;
410 gtp0 = skb_push(skb, sizeof(*gtp0));
412 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
413 gtp0->type = GTP_TPDU;
414 gtp0->length = htons(payload_len);
415 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
416 gtp0->flow = htons(pctx->u.v0.flow);
418 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
419 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
422 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
424 int payload_len = skb->len;
425 struct gtp1_header *gtp1;
427 gtp1 = skb_push(skb, sizeof(*gtp1));
429 /* Bits 8 7 6 5 4 3 2 1
430 * +--+--+--+--+--+--+--+--+
431 * |version |PT| 0| E| S|PN|
432 * +--+--+--+--+--+--+--+--+
435 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
436 gtp1->type = GTP_TPDU;
437 gtp1->length = htons(payload_len);
438 gtp1->tid = htonl(pctx->u.v1.o_tei);
440 /* TODO: Suppport for extension header, sequence number and N-PDU.
441 * Update the length field if any of them is available.
450 struct pdp_ctx *pctx;
451 struct net_device *dev;
455 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
457 switch (pktinfo->pctx->gtp_version) {
459 pktinfo->gtph_port = htons(GTP0_PORT);
460 gtp0_push_header(skb, pktinfo->pctx);
463 pktinfo->gtph_port = htons(GTP1U_PORT);
464 gtp1_push_header(skb, pktinfo->pctx);
469 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
470 struct sock *sk, struct iphdr *iph,
471 struct pdp_ctx *pctx, struct rtable *rt,
473 struct net_device *dev)
477 pktinfo->pctx = pctx;
483 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
484 struct gtp_pktinfo *pktinfo)
486 struct gtp_dev *gtp = netdev_priv(dev);
487 struct pdp_ctx *pctx;
494 /* Read the IP destination address and resolve the PDP context.
495 * Prepend PDP header with TEI/TID from PDP ctx.
498 if (gtp->role == GTP_ROLE_SGSN)
499 pctx = ipv4_pdp_find(gtp, iph->saddr);
501 pctx = ipv4_pdp_find(gtp, iph->daddr);
504 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
508 netdev_dbg(dev, "found PDP context %p\n", pctx);
510 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
512 netdev_dbg(dev, "no route to SSGN %pI4\n",
513 &pctx->peer_addr_ip4.s_addr);
514 dev->stats.tx_carrier_errors++;
518 if (rt->dst.dev == dev) {
519 netdev_dbg(dev, "circular route to SSGN %pI4\n",
520 &pctx->peer_addr_ip4.s_addr);
521 dev->stats.collisions++;
527 /* This is similar to tnl_update_pmtu(). */
530 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
531 sizeof(struct iphdr) - sizeof(struct udphdr);
532 switch (pctx->gtp_version) {
534 mtu -= sizeof(struct gtp0_header);
537 mtu -= sizeof(struct gtp1_header);
541 mtu = dst_mtu(&rt->dst);
544 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
546 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
547 mtu < ntohs(iph->tot_len)) {
548 netdev_dbg(dev, "packet too big, fragmentation needed\n");
549 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
550 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
555 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
556 gtp_push_header(skb, pktinfo);
565 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
567 unsigned int proto = ntohs(skb->protocol);
568 struct gtp_pktinfo pktinfo;
571 /* Ensure there is sufficient headroom. */
572 if (skb_cow_head(skb, dev->needed_headroom))
575 skb_reset_inner_headers(skb);
577 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
581 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
594 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
595 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
596 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
597 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
599 ip4_dst_hoplimit(&pktinfo.rt->dst),
601 pktinfo.gtph_port, pktinfo.gtph_port,
608 dev->stats.tx_errors++;
613 static const struct net_device_ops gtp_netdev_ops = {
614 .ndo_init = gtp_dev_init,
615 .ndo_uninit = gtp_dev_uninit,
616 .ndo_start_xmit = gtp_dev_xmit,
617 .ndo_get_stats64 = ip_tunnel_get_stats64,
620 static void gtp_link_setup(struct net_device *dev)
622 dev->netdev_ops = >p_netdev_ops;
623 dev->needs_free_netdev = true;
625 dev->hard_header_len = 0;
628 /* Zero header length. */
629 dev->type = ARPHRD_NONE;
630 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
632 dev->priv_flags |= IFF_NO_QUEUE;
633 dev->features |= NETIF_F_LLTX;
636 /* Assume largest header, ie. GTPv0. */
637 dev->needed_headroom = LL_MAX_HEADER +
638 sizeof(struct iphdr) +
639 sizeof(struct udphdr) +
640 sizeof(struct gtp0_header);
643 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
644 static void gtp_hashtable_free(struct gtp_dev *gtp);
645 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
647 static int gtp_newlink(struct net *src_net, struct net_device *dev,
648 struct nlattr *tb[], struct nlattr *data[],
649 struct netlink_ext_ack *extack)
655 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
658 gtp = netdev_priv(dev);
660 err = gtp_encap_enable(gtp, data);
664 if (!data[IFLA_GTP_PDP_HASHSIZE])
667 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
669 err = gtp_hashtable_new(gtp, hashsize);
673 err = register_netdevice(dev);
675 netdev_dbg(dev, "failed to register new netdev %d\n", err);
679 gn = net_generic(dev_net(dev), gtp_net_id);
680 list_add_rcu(>p->list, &gn->gtp_dev_list);
682 netdev_dbg(dev, "registered new GTP interface\n");
687 gtp_hashtable_free(gtp);
689 gtp_encap_disable(gtp);
693 static void gtp_dellink(struct net_device *dev, struct list_head *head)
695 struct gtp_dev *gtp = netdev_priv(dev);
697 gtp_encap_disable(gtp);
698 gtp_hashtable_free(gtp);
699 list_del_rcu(>p->list);
700 unregister_netdevice_queue(dev, head);
703 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
704 [IFLA_GTP_FD0] = { .type = NLA_U32 },
705 [IFLA_GTP_FD1] = { .type = NLA_U32 },
706 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
707 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
710 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
711 struct netlink_ext_ack *extack)
719 static size_t gtp_get_size(const struct net_device *dev)
721 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
724 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
726 struct gtp_dev *gtp = netdev_priv(dev);
728 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
729 goto nla_put_failure;
737 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
739 .maxtype = IFLA_GTP_MAX,
740 .policy = gtp_policy,
741 .priv_size = sizeof(struct gtp_dev),
742 .setup = gtp_link_setup,
743 .validate = gtp_validate,
744 .newlink = gtp_newlink,
745 .dellink = gtp_dellink,
746 .get_size = gtp_get_size,
747 .fill_info = gtp_fill_info,
750 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
754 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
756 if (gtp->addr_hash == NULL)
759 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
761 if (gtp->tid_hash == NULL)
764 gtp->hash_size = hsize;
766 for (i = 0; i < hsize; i++) {
767 INIT_HLIST_HEAD(>p->addr_hash[i]);
768 INIT_HLIST_HEAD(>p->tid_hash[i]);
772 kfree(gtp->addr_hash);
776 static void gtp_hashtable_free(struct gtp_dev *gtp)
778 struct pdp_ctx *pctx;
781 for (i = 0; i < gtp->hash_size; i++)
782 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
783 pdp_context_delete(pctx);
786 kfree(gtp->addr_hash);
787 kfree(gtp->tid_hash);
790 static struct sock *gtp_encap_enable_socket(int fd, int type,
793 struct udp_tunnel_sock_cfg tuncfg = {NULL};
798 pr_debug("enable gtp on %d, %d\n", fd, type);
800 sock = sockfd_lookup(fd, &err);
802 pr_debug("gtp socket fd=%d not found\n", fd);
806 if (sock->sk->sk_protocol != IPPROTO_UDP) {
807 pr_debug("socket fd=%d not UDP\n", fd);
808 sk = ERR_PTR(-EINVAL);
813 if (sock->sk->sk_user_data) {
814 sk = ERR_PTR(-EBUSY);
821 tuncfg.sk_user_data = gtp;
822 tuncfg.encap_type = type;
823 tuncfg.encap_rcv = gtp_encap_recv;
824 tuncfg.encap_destroy = gtp_encap_destroy;
826 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
829 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);
854 gtp_encap_disable_sock(sk0);
855 return PTR_ERR(sk1u);
859 if (data[IFLA_GTP_ROLE]) {
860 role = nla_get_u32(data[IFLA_GTP_ROLE]);
861 if (role > GTP_ROLE_SGSN)
872 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
874 struct gtp_dev *gtp = NULL;
875 struct net_device *dev;
878 /* Examine the link attributes and figure out which network namespace
879 * we are talking about.
881 if (nla[GTPA_NET_NS_FD])
882 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
884 net = get_net(src_net);
889 /* Check if there's an existing gtpX device to configure */
890 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
891 if (dev && dev->netdev_ops == >p_netdev_ops)
892 gtp = netdev_priv(dev);
898 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
900 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
902 pctx->peer_addr_ip4.s_addr =
903 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
904 pctx->ms_addr_ip4.s_addr =
905 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
907 switch (pctx->gtp_version) {
909 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
910 * label needs to be the same for uplink and downlink packets,
911 * so let's annotate this.
913 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
914 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
917 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
918 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
925 static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
926 struct genl_info *info)
928 struct net_device *dev = gtp->dev;
929 u32 hash_ms, hash_tid = 0;
930 struct pdp_ctx *pctx;
934 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
935 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
937 hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) {
938 if (pctx->ms_addr_ip4.s_addr == ms_addr) {
945 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
947 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
950 ipv4_pdp_fill(pctx, info);
952 if (pctx->gtp_version == GTP_V0)
953 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
954 pctx->u.v0.tid, pctx);
955 else if (pctx->gtp_version == GTP_V1)
956 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
957 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
963 pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
969 pctx->dev = gtp->dev;
970 ipv4_pdp_fill(pctx, info);
971 atomic_set(&pctx->tx_seq, 0);
973 switch (pctx->gtp_version) {
975 /* TS 09.60: "The flow label identifies unambiguously a GTP
976 * flow.". We use the tid for this instead, I cannot find a
977 * situation in which this doesn't unambiguosly identify the
980 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
983 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
987 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
988 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
990 switch (pctx->gtp_version) {
992 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
993 pctx->u.v0.tid, &pctx->peer_addr_ip4,
994 &pctx->ms_addr_ip4, pctx);
997 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
998 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
999 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1006 static void pdp_context_free(struct rcu_head *head)
1008 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1014 static void pdp_context_delete(struct pdp_ctx *pctx)
1016 hlist_del_rcu(&pctx->hlist_tid);
1017 hlist_del_rcu(&pctx->hlist_addr);
1018 call_rcu(&pctx->rcu_head, pdp_context_free);
1021 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1023 unsigned int version;
1024 struct gtp_dev *gtp;
1028 if (!info->attrs[GTPA_VERSION] ||
1029 !info->attrs[GTPA_LINK] ||
1030 !info->attrs[GTPA_PEER_ADDRESS] ||
1031 !info->attrs[GTPA_MS_ADDRESS])
1034 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1038 if (!info->attrs[GTPA_TID] ||
1039 !info->attrs[GTPA_FLOW])
1043 if (!info->attrs[GTPA_I_TEI] ||
1044 !info->attrs[GTPA_O_TEI])
1055 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1061 if (version == GTP_V0)
1063 else if (version == GTP_V1)
1073 err = ipv4_pdp_add(gtp, sk, info);
1081 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1082 struct nlattr *nla[])
1084 struct gtp_dev *gtp;
1086 gtp = gtp_find_dev(net, nla);
1088 return ERR_PTR(-ENODEV);
1090 if (nla[GTPA_MS_ADDRESS]) {
1091 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1093 return ipv4_pdp_find(gtp, ip);
1094 } else if (nla[GTPA_VERSION]) {
1095 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1097 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1098 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1099 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1100 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1103 return ERR_PTR(-EINVAL);
1106 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1108 struct pdp_ctx *pctx;
1111 pctx = gtp_find_pdp_by_link(net, nla);
1113 pctx = ERR_PTR(-EINVAL);
1116 pctx = ERR_PTR(-ENOENT);
1121 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1123 struct pdp_ctx *pctx;
1126 if (!info->attrs[GTPA_VERSION])
1131 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1133 err = PTR_ERR(pctx);
1137 if (pctx->gtp_version == GTP_V0)
1138 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1139 pctx->u.v0.tid, pctx);
1140 else if (pctx->gtp_version == GTP_V1)
1141 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1142 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1144 pdp_context_delete(pctx);
1151 static struct genl_family gtp_genl_family;
1153 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1154 u32 type, struct pdp_ctx *pctx)
1158 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0,
1163 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1164 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1165 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1166 goto nla_put_failure;
1168 switch (pctx->gtp_version) {
1170 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1171 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1172 goto nla_put_failure;
1175 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1176 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1177 goto nla_put_failure;
1180 genlmsg_end(skb, genlh);
1185 genlmsg_cancel(skb, genlh);
1189 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1191 struct pdp_ctx *pctx = NULL;
1192 struct sk_buff *skb2;
1195 if (!info->attrs[GTPA_VERSION])
1200 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1202 err = PTR_ERR(pctx);
1206 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1212 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1213 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1215 goto err_unlock_free;
1218 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1227 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1228 struct netlink_callback *cb)
1230 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1231 struct net *net = sock_net(skb->sk);
1232 struct gtp_net *gn = net_generic(net, gtp_net_id);
1233 unsigned long tid = cb->args[1];
1234 int i, k = cb->args[0], ret;
1235 struct pdp_ctx *pctx;
1240 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1241 if (last_gtp && last_gtp != gtp)
1246 for (i = k; i < gtp->hash_size; i++) {
1247 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
1248 if (tid && tid != pctx->u.tid)
1253 ret = gtp_genl_fill_info(skb,
1254 NETLINK_CB(cb->skb).portid,
1256 cb->nlh->nlmsg_type, pctx);
1259 cb->args[1] = pctx->u.tid;
1260 cb->args[2] = (unsigned long)gtp;
1271 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1272 [GTPA_LINK] = { .type = NLA_U32, },
1273 [GTPA_VERSION] = { .type = NLA_U32, },
1274 [GTPA_TID] = { .type = NLA_U64, },
1275 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1276 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1277 [GTPA_FLOW] = { .type = NLA_U16, },
1278 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1279 [GTPA_I_TEI] = { .type = NLA_U32, },
1280 [GTPA_O_TEI] = { .type = NLA_U32, },
1283 static const struct genl_ops gtp_genl_ops[] = {
1285 .cmd = GTP_CMD_NEWPDP,
1286 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1287 .doit = gtp_genl_new_pdp,
1288 .flags = GENL_ADMIN_PERM,
1291 .cmd = GTP_CMD_DELPDP,
1292 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1293 .doit = gtp_genl_del_pdp,
1294 .flags = GENL_ADMIN_PERM,
1297 .cmd = GTP_CMD_GETPDP,
1298 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1299 .doit = gtp_genl_get_pdp,
1300 .dumpit = gtp_genl_dump_pdp,
1301 .flags = GENL_ADMIN_PERM,
1305 static struct genl_family gtp_genl_family __ro_after_init = {
1309 .maxattr = GTPA_MAX,
1310 .policy = gtp_genl_policy,
1312 .module = THIS_MODULE,
1313 .ops = gtp_genl_ops,
1314 .n_ops = ARRAY_SIZE(gtp_genl_ops),
1317 static int __net_init gtp_net_init(struct net *net)
1319 struct gtp_net *gn = net_generic(net, gtp_net_id);
1321 INIT_LIST_HEAD(&gn->gtp_dev_list);
1325 static void __net_exit gtp_net_exit(struct net *net)
1327 struct gtp_net *gn = net_generic(net, gtp_net_id);
1328 struct gtp_dev *gtp;
1332 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1333 gtp_dellink(gtp->dev, &list);
1335 unregister_netdevice_many(&list);
1339 static struct pernet_operations gtp_net_ops = {
1340 .init = gtp_net_init,
1341 .exit = gtp_net_exit,
1343 .size = sizeof(struct gtp_net),
1346 static int __init gtp_init(void)
1350 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1352 err = rtnl_link_register(>p_link_ops);
1356 err = genl_register_family(>p_genl_family);
1358 goto unreg_rtnl_link;
1360 err = register_pernet_subsys(>p_net_ops);
1362 goto unreg_genl_family;
1364 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1365 sizeof(struct pdp_ctx));
1369 genl_unregister_family(>p_genl_family);
1371 rtnl_link_unregister(>p_link_ops);
1373 pr_err("error loading GTP module loaded\n");
1376 late_initcall(gtp_init);
1378 static void __exit gtp_fini(void)
1380 unregister_pernet_subsys(>p_net_ops);
1381 genl_unregister_family(>p_genl_family);
1382 rtnl_link_unregister(>p_link_ops);
1384 pr_info("GTP module unloaded\n");
1386 module_exit(gtp_fini);
1388 MODULE_LICENSE("GPL");
1389 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1390 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1391 MODULE_ALIAS_RTNL_LINK("gtp");
1392 MODULE_ALIAS_GENL_FAMILY("gtp");