gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)

This is an initial implementation of a netdev driver for GTP datapath (GTP-U) v0 and v1, according to the GSM TS 09.60 and 3GPP TS 29.060 standards. This tunneling protocol is used to prevent subscribers from accessing mobile carrier core network infrastructure. This implementation requires a GGSN userspace daemon that implements the signaling protocol (GTP-C), such as OpenGGSN [1]. This userspace daemon updates the PDP context database that represents active subscriber sessions through a genetlink interface. For more context on this tunneling protocol, you can check the slides that were presented during the NetDev 1.1 [2]. Only IPv4 is supported at this time. [1] http://git.osmocom.org/openggsn/ [2] http://www.netdevconf.org/1.1/proceedings/slides/schultz-welte-osmocom-gtp.pdf

Pablo Neira committed 10 years ago

Commit 459aa661 parent c047c3b8 files · +1462 −1Browse files

Unified · Split

8 files

drivers/net/Kconfig +17 −0
drivers/net/Makefile +1 −0
drivers/net/gtp.c +1364 −0
include/net/gtp.h +34 −0
include/uapi/linux/Kbuild +1 −0
include/uapi/linux/gtp.h +33 −0
include/uapi/linux/if_link.h +10 −0
include/uapi/linux/udp.h +2 −1

drivers/net/Kconfig+17−0

@@ -192,6 +192,23 @@ config GENEVE · 191 unmodified lines
192	192	To compile this driver as a module, choose M here: the module
193	193	will be called geneve.
194	194
	195	+config GTP
	196	+ tristate "GPRS Tunneling Protocol datapath (GTP-U)"
	197	+ depends on INET && NET_UDP_TUNNEL
	198	+ select NET_IP_TUNNEL
	199	+ ---help---
	200	+ This allows one to create gtp virtual interfaces that provide
	201	+ the GPRS Tunneling Protocol datapath (GTP-U). This tunneling protocol
	202	+ is used to prevent subscribers from accessing mobile carrier core
	203	+ network infrastructure. This driver requires a userspace software that
	204	+ implements the signaling protocol (GTP-C) to update its PDP context
	205	+ base, such as OpenGGSN <http://git.osmocom.org/openggsn/). This
	206	+ tunneling protocol is implemented according to the GSM TS 09.60 and
	207	+ 3GPP TS 29.060 standards.
	208	+
	209	+ To compile this drivers as a module, choose M here: the module
	210	+ wil be called gtp.
	211	+
195	212	config MACSEC
196	213	tristate "IEEE 802.1AE MAC-level encryption (MACsec)"
197	214	select CRYPTO

drivers/net/Makefile+1−0

@@ -25,6 +25,7 @@ obj-$(CONFIG_VETH) += veth.o · 24 unmodified lines
25	25	obj-$(CONFIG_VIRTIO_NET) += virtio_net.o
26	26	obj-$(CONFIG_VXLAN) += vxlan.o
27	27	obj-$(CONFIG_GENEVE) += geneve.o
	28	+obj-$(CONFIG_GTP) += gtp.o
28	29	obj-$(CONFIG_NLMON) += nlmon.o
29	30	obj-$(CONFIG_NET_VRF) += vrf.o
30	31

drivers/net/gtp.c+1364−0

@@ -0,0 +1,1364 @@
	1	+/* GTP according to GSM TS 09.60 / 3GPP TS 29.060
	2	+ *
	3	+ * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
	4	+ * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
	5	+ *
	6	+ * Author: Harald Welte <hwelte@sysmocom.de>
	7	+ * Pablo Neira Ayuso <pablo@netfilter.org>
	8	+ * Andreas Schultz <aschultz@travelping.com>
	9	+ *
	10	+ * This program is free software; you can redistribute it and/or
	11	+ * modify it under the terms of the GNU General Public License
	12	+ * as published by the Free Software Foundation; either version
	13	+ * 2 of the License, or (at your option) any later version.
	14	+ */
	15	+
	16	+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	17	+
	18	+#include <linux/module.h>
	19	+#include <linux/version.h>
	20	+#include <linux/skbuff.h>
	21	+#include <linux/udp.h>
	22	+#include <linux/rculist.h>
	23	+#include <linux/jhash.h>
	24	+#include <linux/if_tunnel.h>
	25	+#include <linux/net.h>
	26	+#include <linux/file.h>
	27	+#include <linux/gtp.h>
	28	+
	29	+#include <net/net_namespace.h>
	30	+#include <net/protocol.h>
	31	+#include <net/ip.h>
	32	+#include <net/udp.h>
	33	+#include <net/udp_tunnel.h>
	34	+#include <net/icmp.h>
	35	+#include <net/xfrm.h>
	36	+#include <net/genetlink.h>
	37	+#include <net/netns/generic.h>
	38	+#include <net/gtp.h>
	39	+
	40	+/* An active session for the subscriber. */
	41	+struct pdp_ctx {
	42	+ struct hlist_node hlist_tid;
	43	+ struct hlist_node hlist_addr;
	44	+
	45	+ union {
	46	+ u64 tid;
	47	+ struct {
	48	+ u64 tid;
	49	+ u16 flow;
	50	+ } v0;
	51	+ struct {
	52	+ u32 i_tei;
	53	+ u32 o_tei;
	54	+ } v1;
	55	+ } u;
	56	+ u8 gtp_version;
	57	+ u16 af;
	58	+
	59	+ struct in_addr ms_addr_ip4;
	60	+ struct in_addr sgsn_addr_ip4;
	61	+
	62	+ atomic_t tx_seq;
	63	+ struct rcu_head rcu_head;
	64	+};
	65	+
	66	+/* One instance of the GTP device. */
	67	+struct gtp_dev {
	68	+ struct list_head list;
	69	+
	70	+ struct socket *sock0;
	71	+ struct socket *sock1u;
	72	+
	73	+ struct net *net;
	74	+ struct net_device *dev;
	75	+
	76	+ unsigned int hash_size;
	77	+ struct hlist_head *tid_hash;
	78	+ struct hlist_head *addr_hash;
	79	+};
	80	+
	81	+static int gtp_net_id __read_mostly;
	82	+
	83	+struct gtp_net {
	84	+ struct list_head gtp_dev_list;
	85	+};
	86	+
	87	+static u32 gtp_h_initval;
	88	+
	89	+static inline u32 gtp0_hashfn(u64 tid)
	90	+{
	91	+ u32 tid32 = (u32 ) &tid;
	92	+ return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
	93	+}
	94	+
	95	+static inline u32 gtp1u_hashfn(u32 tid)
	96	+{
	97	+ return jhash_1word(tid, gtp_h_initval);
	98	+}
	99	+
	100	+static inline u32 ipv4_hashfn(__be32 ip)
	101	+{
	102	+ return jhash_1word((__force u32)ip, gtp_h_initval);
	103	+}
	104	+
	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)
	107	+{
	108	+ struct hlist_head *head;
	109	+ struct pdp_ctx *pdp;
	110	+
	111	+ head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
	112	+
	113	+ hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
	114	+ if (pdp->gtp_version == GTP_V0 &&
	115	+ pdp->u.v0.tid == tid)
	116	+ return pdp;
	117	+ }
	118	+ return NULL;
	119	+}
	120	+
	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)
	123	+{
	124	+ struct hlist_head *head;
	125	+ struct pdp_ctx *pdp;
	126	+
	127	+ head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
	128	+
	129	+ hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
	130	+ if (pdp->gtp_version == GTP_V1 &&
	131	+ pdp->u.v1.i_tei == tid)
	132	+ return pdp;
	133	+ }
	134	+ return NULL;
	135	+}
	136	+
	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)
	139	+{
	140	+ struct hlist_head *head;
	141	+ struct pdp_ctx *pdp;
	142	+
	143	+ head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
	144	+
	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)
	148	+ return pdp;
	149	+ }
	150	+
	151	+ return NULL;
	152	+}
	153	+
	154	+static bool gtp_check_src_ms_ipv4(struct sk_buff skb, struct pdp_ctx pctx,
	155	+ unsigned int hdrlen)
	156	+{
	157	+ struct iphdr *iph;
	158	+
	159	+ if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
	160	+ return false;
	161	+
	162	+ iph = (struct iphdr *)(skb->data + hdrlen + sizeof(struct iphdr));
	163	+
	164	+ return iph->saddr != pctx->ms_addr_ip4.s_addr;
	165	+}
	166	+
	167	+/* Check if the inner IP source address in this packet is assigned to any
	168	+ * existing mobile subscriber.
	169	+ */
	170	+static bool gtp_check_src_ms(struct sk_buff skb, struct pdp_ctx pctx,
	171	+ unsigned int hdrlen)
	172	+{
	173	+ switch (ntohs(skb->protocol)) {
	174	+ case ETH_P_IP:
	175	+ return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
	176	+ }
	177	+ return false;
	178	+}
	179	+
	180	+/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
	181	+static int gtp0_udp_encap_recv(struct gtp_dev gtp, struct sk_buff skb,
	182	+ bool xnet)
	183	+{
	184	+ unsigned int hdrlen = sizeof(struct udphdr) +
	185	+ sizeof(struct gtp0_header);
	186	+ struct gtp0_header *gtp0;
	187	+ struct pdp_ctx *pctx;
	188	+ int ret = 0;
	189	+
	190	+ if (!pskb_may_pull(skb, hdrlen))
	191	+ return -1;
	192	+
	193	+ gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
	194	+
	195	+ if ((gtp0->flags >> 5) != GTP_V0)
	196	+ return 1;
	197	+
	198	+ if (gtp0->type != GTP_TPDU)
	199	+ return 1;
	200	+
	201	+ rcu_read_lock();
	202	+ pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
	203	+ if (!pctx) {
	204	+ netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
	205	+ ret = -1;
	206	+ goto out_rcu;
	207	+ }
	208	+
	209	+ if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
	210	+ netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
	211	+ ret = -1;
	212	+ goto out_rcu;
	213	+ }
	214	+ rcu_read_unlock();
	215	+
	216	+ /* Get rid of the GTP + UDP headers. */
	217	+ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
	218	+out_rcu:
	219	+ rcu_read_unlock();
	220	+ return ret;
	221	+}
	222	+
	223	+static int gtp1u_udp_encap_recv(struct gtp_dev gtp, struct sk_buff skb,
	224	+ bool xnet)
	225	+{
	226	+ unsigned int hdrlen = sizeof(struct udphdr) +
	227	+ sizeof(struct gtp1_header);
	228	+ struct gtp1_header *gtp1;
	229	+ struct pdp_ctx *pctx;
	230	+ int ret = 0;
	231	+
	232	+ if (!pskb_may_pull(skb, hdrlen))
	233	+ return -1;
	234	+
	235	+ gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
	236	+
	237	+ if ((gtp1->flags >> 5) != GTP_V1)
	238	+ return 1;
	239	+
	240	+ if (gtp1->type != GTP_TPDU)
	241	+ return 1;
	242	+
	243	+ /* From 29.060: "This field shall be present if and only if any one or
	244	+ * more of the S, PN and E flags are set.".
	245	+ *
	246	+ * If any of the bit is set, then the remaining ones also have to be
	247	+ * set.
	248	+ */
	249	+ if (gtp1->flags & GTP1_F_MASK)
	250	+ hdrlen += 4;
	251	+
	252	+ /* Make sure the header is larger enough, including extensions. */
	253	+ if (!pskb_may_pull(skb, hdrlen))
	254	+ return -1;
	255	+
	256	+ rcu_read_lock();
	257	+ pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
	258	+ if (!pctx) {
	259	+ netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
	260	+ ret = -1;
	261	+ goto out_rcu;
	262	+ }
	263	+
	264	+ if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
	265	+ netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
	266	+ ret = -1;
	267	+ goto out_rcu;
	268	+ }
	269	+ rcu_read_unlock();
	270	+
	271	+ /* Get rid of the GTP + UDP headers. */
	272	+ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
	273	+out_rcu:
	274	+ rcu_read_unlock();
	275	+ return ret;
	276	+}
	277	+
	278	+static void gtp_encap_disable(struct gtp_dev *gtp)
	279	+{
	280	+ if (gtp->sock0 && gtp->sock0->sk) {
	281	+ udp_sk(gtp->sock0->sk)->encap_type = 0;
	282	+ rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
	283	+ }
	284	+ if (gtp->sock1u && gtp->sock1u->sk) {
	285	+ udp_sk(gtp->sock1u->sk)->encap_type = 0;
	286	+ rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
	287	+ }
	288	+
	289	+ gtp->sock0 = NULL;
	290	+ gtp->sock1u = NULL;
	291	+}
	292	+
	293	+static void gtp_encap_destroy(struct sock *sk)
	294	+{
	295	+ struct gtp_dev *gtp;
	296	+
	297	+ gtp = rcu_dereference_sk_user_data(sk);
	298	+ if (gtp)
	299	+ gtp_encap_disable(gtp);
	300	+}
	301	+
	302	+/* UDP encapsulation receive handler. See net/ipv4/udp.c.
	303	+ * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
	304	+ */
	305	+static int gtp_encap_recv(struct sock sk, struct sk_buff skb)
	306	+{
	307	+ struct pcpu_sw_netstats *stats;
	308	+ struct gtp_dev *gtp;
	309	+ bool xnet;
	310	+ int ret;
	311	+
	312	+ gtp = rcu_dereference_sk_user_data(sk);
	313	+ if (!gtp)
	314	+ return 1;
	315	+
	316	+ netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
	317	+
	318	+ xnet = !net_eq(gtp->net, dev_net(gtp->dev));
	319	+
	320	+ switch (udp_sk(sk)->encap_type) {
	321	+ case UDP_ENCAP_GTP0:
	322	+ netdev_dbg(gtp->dev, "received GTP0 packet\n");
	323	+ ret = gtp0_udp_encap_recv(gtp, skb, xnet);
	324	+ break;
	325	+ case UDP_ENCAP_GTP1U:
	326	+ netdev_dbg(gtp->dev, "received GTP1U packet\n");
	327	+ ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
	328	+ break;
	329	+ default:
	330	+ ret = -1; /* Shouldn't happen. */
	331	+ }
	332	+
	333	+ switch (ret) {
	334	+ case 1:
	335	+ netdev_dbg(gtp->dev, "pass up to the process\n");
	336	+ return 1;
	337	+ case 0:
	338	+ netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
	339	+ break;
	340	+ case -1:
	341	+ netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
	342	+ kfree_skb(skb);
	343	+ return 0;
	344	+ }
	345	+
	346	+ /* Now that the UDP and the GTP header have been removed, set up the
	347	+ * new network header. This is required by the upper layer to
	348	+ * calculate the transport header.
	349	+ */
	350	+ skb_reset_network_header(skb);
	351	+
	352	+ skb->dev = gtp->dev;
	353	+
	354	+ stats = this_cpu_ptr(gtp->dev->tstats);
	355	+ u64_stats_update_begin(&stats->syncp);
	356	+ stats->rx_packets++;
	357	+ stats->rx_bytes += skb->len;
	358	+ u64_stats_update_end(&stats->syncp);
	359	+
	360	+ netif_rx(skb);
	361	+
	362	+ return 0;
	363	+}
	364	+
	365	+static int gtp_dev_init(struct net_device *dev)
	366	+{
	367	+ struct gtp_dev *gtp = netdev_priv(dev);
	368	+
	369	+ gtp->dev = dev;
	370	+
	371	+ dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
	372	+ if (!dev->tstats)
	373	+ return -ENOMEM;
	374	+
	375	+ return 0;
	376	+}
	377	+
	378	+static void gtp_dev_uninit(struct net_device *dev)
	379	+{
	380	+ struct gtp_dev *gtp = netdev_priv(dev);
	381	+
	382	+ gtp_encap_disable(gtp);
	383	+ free_percpu(dev->tstats);
	384	+}
	385	+
	386	+static struct rtable ip4_route_output_gtp(struct net net, struct flowi4 *fl4,
	387	+ const struct sock *sk, __be32 daddr)
	388	+{
	389	+ memset(fl4, 0, sizeof(*fl4));
	390	+ fl4->flowi4_oif = sk->sk_bound_dev_if;
	391	+ fl4->daddr = daddr;
	392	+ fl4->saddr = inet_sk(sk)->inet_saddr;
	393	+ fl4->flowi4_tos = RT_CONN_FLAGS(sk);
	394	+ fl4->flowi4_proto = sk->sk_protocol;
	395	+
	396	+ return ip_route_output_key(net, fl4);
	397	+}
	398	+
	399	+static inline void gtp0_push_header(struct sk_buff skb, struct pdp_ctx pctx)
	400	+{
	401	+ int payload_len = skb->len;
	402	+ struct gtp0_header *gtp0;
	403	+
	404	+ gtp0 = (struct gtp0_header ) skb_push(skb, sizeof(gtp0));
	405	+
	406	+ gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
	407	+ gtp0->type = GTP_TPDU;
	408	+ gtp0->length = htons(payload_len);
	409	+ gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
	410	+ gtp0->flow = htons(pctx->u.v0.flow);
	411	+ gtp0->number = 0xff;
	412	+ gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
	413	+ gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
	414	+}
	415	+
	416	+static inline void gtp1_push_header(struct sk_buff skb, struct pdp_ctx pctx)
	417	+{
	418	+ int payload_len = skb->len;
	419	+ struct gtp1_header *gtp1;
	420	+
	421	+ gtp1 = (struct gtp1_header ) skb_push(skb, sizeof(gtp1));
	422	+
	423	+ /* Bits 8 7 6 5 4 3 2 1
	424	+ * +--+--+--+--+--+--+--+--+
	425	+ * \|version \|PT\| 1\| E\| S\|PN\|
	426	+ * +--+--+--+--+--+--+--+--+
	427	+ * 0 0 1 1 1 0 0 0
	428	+ */
	429	+ gtp1->flags = 0x38; /* v1, GTP-non-prime. */
	430	+ gtp1->type = GTP_TPDU;
	431	+ gtp1->length = htons(payload_len);
	432	+ gtp1->tid = htonl(pctx->u.v1.o_tei);
	433	+
	434	+ /* TODO: Suppport for extension header, sequence number and N-PDU.
	435	+ * Update the length field if any of them is available.
	436	+ */
	437	+}
	438	+
	439	+struct gtp_pktinfo {
	440	+ struct sock *sk;
	441	+ struct iphdr *iph;
	442	+ struct flowi4 fl4;
	443	+ struct rtable *rt;
	444	+ struct pdp_ctx *pctx;
	445	+ struct net_device *dev;
	446	+ __be16 gtph_port;
	447	+};
	448	+
	449	+static void gtp_push_header(struct sk_buff skb, struct gtp_pktinfo pktinfo)
	450	+{
	451	+ switch (pktinfo->pctx->gtp_version) {
	452	+ case GTP_V0:
	453	+ pktinfo->gtph_port = htons(GTP0_PORT);
	454	+ gtp0_push_header(skb, pktinfo->pctx);
	455	+ break;
	456	+ case GTP_V1:
	457	+ pktinfo->gtph_port = htons(GTP1U_PORT);
	458	+ gtp1_push_header(skb, pktinfo->pctx);
	459	+ break;
	460	+ }
	461	+}
	462	+
	463	+static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
	464	+ struct sock sk, struct iphdr iph,
	465	+ struct pdp_ctx pctx, struct rtable rt,
	466	+ struct flowi4 *fl4,
	467	+ struct net_device *dev)
	468	+{
	469	+ pktinfo->sk = sk;
	470	+ pktinfo->iph = iph;
	471	+ pktinfo->pctx = pctx;
	472	+ pktinfo->rt = rt;
	473	+ pktinfo->fl4 = *fl4;
	474	+ pktinfo->dev = dev;
	475	+}
	476	+
	477	+static int gtp_build_skb_ip4(struct sk_buff skb, struct net_device dev,
	478	+ struct gtp_pktinfo *pktinfo)
	479	+{
	480	+ struct gtp_dev *gtp = netdev_priv(dev);
	481	+ struct pdp_ctx *pctx;
	482	+ struct rtable *rt;
	483	+ struct flowi4 fl4;
	484	+ struct iphdr *iph;
	485	+ struct sock *sk;
	486	+ __be16 df;
	487	+ int mtu;
	488	+
	489	+ /* Read the IP destination address and resolve the PDP context.
	490	+ * Prepend PDP header with TEI/TID from PDP ctx.
	491	+ */
	492	+ iph = ip_hdr(skb);
	493	+ pctx = ipv4_pdp_find(gtp, iph->daddr);
	494	+ if (!pctx) {
	495	+ netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
	496	+ &iph->daddr);
	497	+ return -ENOENT;
	498	+ }
	499	+ netdev_dbg(dev, "found PDP context %p\n", pctx);
	500	+
	501	+ switch (pctx->gtp_version) {
	502	+ case GTP_V0:
	503	+ if (gtp->sock0)
	504	+ sk = gtp->sock0->sk;
	505	+ else
	506	+ sk = NULL;
	507	+ break;
	508	+ case GTP_V1:
	509	+ if (gtp->sock1u)
	510	+ sk = gtp->sock1u->sk;
	511	+ else
	512	+ sk = NULL;
	513	+ break;
	514	+ default:
	515	+ return -ENOENT;
	516	+ }
	517	+
	518	+ if (!sk) {
	519	+ netdev_dbg(dev, "no userspace socket is available, skip\n");
	520	+ return -ENOENT;
	521	+ }
	522	+
	523	+ rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
	524	+ pctx->sgsn_addr_ip4.s_addr);
	525	+ if (IS_ERR(rt)) {
	526	+ netdev_dbg(dev, "no route to SSGN %pI4\n",
	527	+ &pctx->sgsn_addr_ip4.s_addr);
	528	+ dev->stats.tx_carrier_errors++;
	529	+ goto err;
	530	+ }
	531	+
	532	+ if (rt->dst.dev == dev) {
	533	+ netdev_dbg(dev, "circular route to SSGN %pI4\n",
	534	+ &pctx->sgsn_addr_ip4.s_addr);
	535	+ dev->stats.collisions++;
	536	+ goto err_rt;
	537	+ }
	538	+
	539	+ skb_dst_drop(skb);
	540	+
	541	+ /* This is similar to tnl_update_pmtu(). */
	542	+ df = iph->frag_off;
	543	+ if (df) {
	544	+ mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
	545	+ sizeof(struct iphdr) - sizeof(struct udphdr);
	546	+ switch (pctx->gtp_version) {
	547	+ case GTP_V0:
	548	+ mtu -= sizeof(struct gtp0_header);
	549	+ break;
	550	+ case GTP_V1:
	551	+ mtu -= sizeof(struct gtp1_header);
	552	+ break;
	553	+ }
	554	+ } else {
	555	+ mtu = dst_mtu(&rt->dst);
	556	+ }
	557	+
	558	+ rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
	559	+
	560	+ if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
	561	+ mtu < ntohs(iph->tot_len)) {
	562	+ netdev_dbg(dev, "packet too big, fragmentation needed\n");
	563	+ memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
	564	+ icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
	565	+ htonl(mtu));
	566	+ goto err_rt;
	567	+ }
	568	+
	569	+ gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
	570	+ gtp_push_header(skb, pktinfo);
	571	+
	572	+ return 0;
	573	+err_rt:
	574	+ ip_rt_put(rt);
	575	+err:
	576	+ return -EBADMSG;
	577	+}
	578	+
	579	+static netdev_tx_t gtp_dev_xmit(struct sk_buff skb, struct net_device dev)
	580	+{
	581	+ unsigned int proto = ntohs(skb->protocol);
	582	+ struct gtp_pktinfo pktinfo;
	583	+ int err;
	584	+
	585	+ /* Ensure there is sufficient headroom. */
	586	+ if (skb_cow_head(skb, dev->needed_headroom))
	587	+ goto tx_err;
	588	+
	589	+ skb_reset_inner_headers(skb);
	590	+
	591	+ /* PDP context lookups in gtp_build_skb_() need rcu read-side lock. /
	592	+ rcu_read_lock();
	593	+ switch (proto) {
	594	+ case ETH_P_IP:
	595	+ err = gtp_build_skb_ip4(skb, dev, &pktinfo);
	596	+ break;
	597	+ default:
	598	+ err = -EOPNOTSUPP;
	599	+ break;
	600	+ }
	601	+ rcu_read_unlock();
	602	+
	603	+ if (err < 0)
	604	+ goto tx_err;
	605	+
	606	+ switch (proto) {
	607	+ case ETH_P_IP:
	608	+ netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
	609	+ &pktinfo.iph->saddr, &pktinfo.iph->daddr);
	610	+ udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
	611	+ pktinfo.fl4.saddr, pktinfo.fl4.daddr,
	612	+ pktinfo.iph->tos,
	613	+ ip4_dst_hoplimit(&pktinfo.rt->dst),
	614	+ htons(IP_DF),
	615	+ pktinfo.gtph_port, pktinfo.gtph_port,
	616	+ true, false);
	617	+ break;
	618	+ }
	619	+
	620	+ return NETDEV_TX_OK;
	621	+tx_err:
	622	+ dev->stats.tx_errors++;
	623	+ dev_kfree_skb(skb);
	624	+ return NETDEV_TX_OK;
	625	+}
	626	+
	627	+static const struct net_device_ops gtp_netdev_ops = {
	628	+ .ndo_init = gtp_dev_init,
	629	+ .ndo_uninit = gtp_dev_uninit,
	630	+ .ndo_start_xmit = gtp_dev_xmit,
	631	+ .ndo_get_stats64 = ip_tunnel_get_stats64,
	632	+};
	633	+
	634	+static void gtp_link_setup(struct net_device *dev)
	635	+{
	636	+ dev->netdev_ops = &gtp_netdev_ops;
	637	+ dev->destructor = free_netdev;
	638	+
	639	+ dev->hard_header_len = 0;
	640	+ dev->addr_len = 0;
	641	+
	642	+ /* Zero header length. */
	643	+ dev->type = ARPHRD_NONE;
	644	+ dev->flags = IFF_POINTOPOINT \| IFF_NOARP \| IFF_MULTICAST;
	645	+
	646	+ dev->priv_flags \|= IFF_NO_QUEUE;
	647	+ dev->features \|= NETIF_F_LLTX;
	648	+ netif_keep_dst(dev);
	649	+
	650	+ /* Assume largest header, ie. GTPv0. */
	651	+ dev->needed_headroom = LL_MAX_HEADER +
	652	+ sizeof(struct iphdr) +
	653	+ sizeof(struct udphdr) +
	654	+ sizeof(struct gtp0_header);
	655	+}
	656	+
	657	+static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
	658	+static void gtp_hashtable_free(struct gtp_dev *gtp);
	659	+static int gtp_encap_enable(struct net_device dev, struct gtp_dev gtp,
	660	+ int fd_gtp0, int fd_gtp1, struct net *src_net);
	661	+
	662	+static int gtp_newlink(struct net src_net, struct net_device dev,
	663	+ struct nlattr tb[], struct nlattr data[])
	664	+{
	665	+ int hashsize, err, fd0, fd1;
	666	+ struct gtp_dev *gtp;
	667	+ struct gtp_net *gn;
	668	+
	669	+ if (!data[IFLA_GTP_FD0] \|\| !data[IFLA_GTP_FD1])
	670	+ return -EINVAL;
	671	+
	672	+ gtp = netdev_priv(dev);
	673	+
	674	+ fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
	675	+ fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
	676	+
	677	+ err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net);
	678	+ if (err < 0)
	679	+ goto out_err;
	680	+
	681	+ if (!data[IFLA_GTP_PDP_HASHSIZE])
	682	+ hashsize = 1024;
	683	+ else
	684	+ hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
	685	+
	686	+ err = gtp_hashtable_new(gtp, hashsize);
	687	+ if (err < 0)
	688	+ goto out_encap;
	689	+
	690	+ err = register_netdevice(dev);
	691	+ if (err < 0) {
	692	+ netdev_dbg(dev, "failed to register new netdev %d\n", err);
	693	+ goto out_hashtable;
	694	+ }
	695	+
	696	+ gn = net_generic(dev_net(dev), gtp_net_id);
	697	+ list_add_rcu(&gtp->list, &gn->gtp_dev_list);
	698	+
	699	+ netdev_dbg(dev, "registered new GTP interface\n");
	700	+
	701	+ return 0;
	702	+
	703	+out_hashtable:
	704	+ gtp_hashtable_free(gtp);
	705	+out_encap:
	706	+ gtp_encap_disable(gtp);
	707	+out_err:
	708	+ return err;
	709	+}
	710	+
	711	+static void gtp_dellink(struct net_device dev, struct list_head head)
	712	+{
	713	+ struct gtp_dev *gtp = netdev_priv(dev);
	714	+
	715	+ gtp_encap_disable(gtp);
	716	+ gtp_hashtable_free(gtp);
	717	+ list_del_rcu(&gtp->list);
	718	+ unregister_netdevice_queue(dev, head);
	719	+}
	720	+
	721	+static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
	722	+ [IFLA_GTP_FD0] = { .type = NLA_U32 },
	723	+ [IFLA_GTP_FD1] = { .type = NLA_U32 },
	724	+ [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
	725	+};
	726	+
	727	+static int gtp_validate(struct nlattr tb[], struct nlattr data[])
	728	+{
	729	+ if (!data)
	730	+ return -EINVAL;
	731	+
	732	+ return 0;
	733	+}
	734	+
	735	+static size_t gtp_get_size(const struct net_device *dev)
	736	+{
	737	+ return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
	738	+}
	739	+
	740	+static int gtp_fill_info(struct sk_buff skb, const struct net_device dev)
	741	+{
	742	+ struct gtp_dev *gtp = netdev_priv(dev);
	743	+
	744	+ if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
	745	+ goto nla_put_failure;
	746	+
	747	+ return 0;
	748	+
	749	+nla_put_failure:
	750	+ return -EMSGSIZE;
	751	+}
	752	+
	753	+static struct rtnl_link_ops gtp_link_ops __read_mostly = {
	754	+ .kind = "gtp",
	755	+ .maxtype = IFLA_GTP_MAX,
	756	+ .policy = gtp_policy,
	757	+ .priv_size = sizeof(struct gtp_dev),
	758	+ .setup = gtp_link_setup,
	759	+ .validate = gtp_validate,
	760	+ .newlink = gtp_newlink,
	761	+ .dellink = gtp_dellink,
	762	+ .get_size = gtp_get_size,
	763	+ .fill_info = gtp_fill_info,
	764	+};
	765	+
	766	+static struct net gtp_genl_get_net(struct net src_net, struct nlattr *tb[])
	767	+{
	768	+ struct net *net;
	769	+
	770	+ /* Examine the link attributes and figure out which network namespace
	771	+ * we are talking about.
	772	+ */
	773	+ if (tb[GTPA_NET_NS_FD])
	774	+ net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));
	775	+ else
	776	+ net = get_net(src_net);
	777	+
	778	+ return net;
	779	+}
	780	+
	781	+static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
	782	+{
	783	+ int i;
	784	+
	785	+ gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
	786	+ if (gtp->addr_hash == NULL)
	787	+ return -ENOMEM;
	788	+
	789	+ gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
	790	+ if (gtp->tid_hash == NULL)
	791	+ goto err1;
	792	+
	793	+ gtp->hash_size = hsize;
	794	+
	795	+ for (i = 0; i < hsize; i++) {
	796	+ INIT_HLIST_HEAD(&gtp->addr_hash[i]);
	797	+ INIT_HLIST_HEAD(&gtp->tid_hash[i]);
	798	+ }
	799	+ return 0;
	800	+err1:
	801	+ kfree(gtp->addr_hash);
	802	+ return -ENOMEM;
	803	+}
	804	+
	805	+static void gtp_hashtable_free(struct gtp_dev *gtp)
	806	+{
	807	+ struct pdp_ctx *pctx;
	808	+ int i;
	809	+
	810	+ for (i = 0; i < gtp->hash_size; i++) {
	811	+ hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
	812	+ hlist_del_rcu(&pctx->hlist_tid);
	813	+ hlist_del_rcu(&pctx->hlist_addr);
	814	+ kfree_rcu(pctx, rcu_head);
	815	+ }
	816	+ }
	817	+ synchronize_rcu();
	818	+ kfree(gtp->addr_hash);
	819	+ kfree(gtp->tid_hash);
	820	+}
	821	+
	822	+static int gtp_encap_enable(struct net_device dev, struct gtp_dev gtp,
	823	+ int fd_gtp0, int fd_gtp1, struct net *src_net)
	824	+{
	825	+ struct udp_tunnel_sock_cfg tuncfg = {NULL};
	826	+ struct socket sock0, sock1u;
	827	+ int err;
	828	+
	829	+ netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
	830	+
	831	+ sock0 = sockfd_lookup(fd_gtp0, &err);
	832	+ if (sock0 == NULL) {
	833	+ netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
	834	+ return -ENOENT;
	835	+ }
	836	+
	837	+ if (sock0->sk->sk_protocol != IPPROTO_UDP) {
	838	+ netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
	839	+ err = -EINVAL;
	840	+ goto err1;
	841	+ }
	842	+
	843	+ sock1u = sockfd_lookup(fd_gtp1, &err);
	844	+ if (sock1u == NULL) {
	845	+ netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
	846	+ err = -ENOENT;
	847	+ goto err1;
	848	+ }
	849	+
	850	+ if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
	851	+ netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
	852	+ err = -EINVAL;
	853	+ goto err2;
	854	+ }
	855	+
	856	+ netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
	857	+
	858	+ gtp->sock0 = sock0;
	859	+ gtp->sock1u = sock1u;
	860	+ gtp->net = src_net;
	861	+
	862	+ tuncfg.sk_user_data = gtp;
	863	+ tuncfg.encap_rcv = gtp_encap_recv;
	864	+ tuncfg.encap_destroy = gtp_encap_destroy;
	865	+
	866	+ tuncfg.encap_type = UDP_ENCAP_GTP0;
	867	+ setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
	868	+
	869	+ tuncfg.encap_type = UDP_ENCAP_GTP1U;
	870	+ setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
	871	+
	872	+ err = 0;
	873	+err2:
	874	+ sockfd_put(sock1u);
	875	+err1:
	876	+ sockfd_put(sock0);
	877	+ return err;
	878	+}
	879	+
	880	+static struct net_device gtp_find_dev(struct net net, int ifindex)
	881	+{
	882	+ struct gtp_net *gn = net_generic(net, gtp_net_id);
	883	+ struct gtp_dev *gtp;
	884	+
	885	+ list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
	886	+ if (ifindex == gtp->dev->ifindex)
	887	+ return gtp->dev;
	888	+ }
	889	+ return NULL;
	890	+}
	891	+
	892	+static void ipv4_pdp_fill(struct pdp_ctx pctx, struct genl_info info)
	893	+{
	894	+ pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
	895	+ pctx->af = AF_INET;
	896	+ pctx->sgsn_addr_ip4.s_addr =
	897	+ nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
	898	+ pctx->ms_addr_ip4.s_addr =
	899	+ nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
	900	+
	901	+ switch (pctx->gtp_version) {
	902	+ case GTP_V0:
	903	+ /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
	904	+ * label needs to be the same for uplink and downlink packets,
	905	+ * so let's annotate this.
	906	+ */
	907	+ pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
	908	+ pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
	909	+ break;
	910	+ case GTP_V1:
	911	+ pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
	912	+ pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
	913	+ break;
	914	+ default:
	915	+ break;
	916	+ }
	917	+}
	918	+
	919	+static int ipv4_pdp_add(struct net_device dev, struct genl_info info)
	920	+{
	921	+ struct gtp_dev *gtp = netdev_priv(dev);
	922	+ u32 hash_ms, hash_tid = 0;
	923	+ struct pdp_ctx *pctx;
	924	+ bool found = false;
	925	+ __be32 ms_addr;
	926	+
	927	+ ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
	928	+ hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
	929	+
	930	+ hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
	931	+ if (pctx->ms_addr_ip4.s_addr == ms_addr) {
	932	+ found = true;
	933	+ break;
	934	+ }
	935	+ }
	936	+
	937	+ if (found) {
	938	+ if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
	939	+ return -EEXIST;
	940	+ if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
	941	+ return -EOPNOTSUPP;
	942	+
	943	+ ipv4_pdp_fill(pctx, info);
	944	+
	945	+ if (pctx->gtp_version == GTP_V0)
	946	+ netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
	947	+ pctx->u.v0.tid, pctx);
	948	+ else if (pctx->gtp_version == GTP_V1)
	949	+ netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
	950	+ pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
	951	+
	952	+ return 0;
	953	+
	954	+ }
	955	+
	956	+ pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
	957	+ if (pctx == NULL)
	958	+ return -ENOMEM;
	959	+
	960	+ ipv4_pdp_fill(pctx, info);
	961	+ atomic_set(&pctx->tx_seq, 0);
	962	+
	963	+ switch (pctx->gtp_version) {
	964	+ case GTP_V0:
	965	+ /* TS 09.60: "The flow label identifies unambiguously a GTP
	966	+ * flow.". We use the tid for this instead, I cannot find a
	967	+ * situation in which this doesn't unambiguosly identify the
	968	+ * PDP context.
	969	+ */
	970	+ hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
	971	+ break;
	972	+ case GTP_V1:
	973	+ hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
	974	+ break;
	975	+ }
	976	+
	977	+ hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
	978	+ hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
	979	+
	980	+ switch (pctx->gtp_version) {
	981	+ case GTP_V0:
	982	+ netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
	983	+ pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
	984	+ &pctx->ms_addr_ip4, pctx);
	985	+ break;
	986	+ case GTP_V1:
	987	+ netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
	988	+ pctx->u.v1.i_tei, pctx->u.v1.o_tei,
	989	+ &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
	990	+ break;
	991	+ }
	992	+
	993	+ return 0;
	994	+}
	995	+
	996	+static int gtp_genl_new_pdp(struct sk_buff skb, struct genl_info info)
	997	+{
	998	+ struct net_device *dev;
	999	+ struct net *net;
	1000	+
	1001	+ if (!info->attrs[GTPA_VERSION] \|\|
	1002	+ !info->attrs[GTPA_LINK] \|\|
	1003	+ !info->attrs[GTPA_SGSN_ADDRESS] \|\|
	1004	+ !info->attrs[GTPA_MS_ADDRESS])
	1005	+ return -EINVAL;
	1006	+
	1007	+ switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
	1008	+ case GTP_V0:
	1009	+ if (!info->attrs[GTPA_TID] \|\|
	1010	+ !info->attrs[GTPA_FLOW])
	1011	+ return -EINVAL;
	1012	+ break;
	1013	+ case GTP_V1:
	1014	+ if (!info->attrs[GTPA_I_TEI] \|\|
	1015	+ !info->attrs[GTPA_O_TEI])
	1016	+ return -EINVAL;
	1017	+ break;
	1018	+
	1019	+ default:
	1020	+ return -EINVAL;
	1021	+ }
	1022	+
	1023	+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
	1024	+ if (IS_ERR(net))
	1025	+ return PTR_ERR(net);
	1026	+
	1027	+ /* Check if there's an existing gtpX device to configure */
	1028	+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
	1029	+ if (dev == NULL)
	1030	+ return -ENODEV;
	1031	+
	1032	+ return ipv4_pdp_add(dev, info);
	1033	+}
	1034	+
	1035	+static int gtp_genl_del_pdp(struct sk_buff skb, struct genl_info info)
	1036	+{
	1037	+ struct net_device *dev;
	1038	+ struct pdp_ctx *pctx;
	1039	+ struct gtp_dev *gtp;
	1040	+ struct net *net;
	1041	+
	1042	+ if (!info->attrs[GTPA_VERSION] \|\|
	1043	+ !info->attrs[GTPA_LINK])
	1044	+ return -EINVAL;
	1045	+
	1046	+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
	1047	+ if (IS_ERR(net))
	1048	+ return PTR_ERR(net);
	1049	+
	1050	+ /* Check if there's an existing gtpX device to configure */
	1051	+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
	1052	+ if (dev == NULL)
	1053	+ return -ENODEV;
	1054	+
	1055	+ gtp = netdev_priv(dev);
	1056	+
	1057	+ switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
	1058	+ case GTP_V0:
	1059	+ if (!info->attrs[GTPA_TID])
	1060	+ return -EINVAL;
	1061	+ pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
	1062	+ break;
	1063	+ case GTP_V1:
	1064	+ if (!info->attrs[GTPA_I_TEI])
	1065	+ return -EINVAL;
	1066	+ pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
	1067	+ break;
	1068	+
	1069	+ default:
	1070	+ return -EINVAL;
	1071	+ }
	1072	+
	1073	+ if (pctx == NULL)
	1074	+ return -ENOENT;
	1075	+
	1076	+ if (pctx->gtp_version == GTP_V0)
	1077	+ netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
	1078	+ pctx->u.v0.tid, pctx);
	1079	+ else if (pctx->gtp_version == GTP_V1)
	1080	+ netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
	1081	+ pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
	1082	+
	1083	+ hlist_del_rcu(&pctx->hlist_tid);
	1084	+ hlist_del_rcu(&pctx->hlist_addr);
	1085	+ kfree_rcu(pctx, rcu_head);
	1086	+
	1087	+ return 0;
	1088	+}
	1089	+
	1090	+static struct genl_family gtp_genl_family = {
	1091	+ .id = GENL_ID_GENERATE,
	1092	+ .name = "gtp",
	1093	+ .version = 0,
	1094	+ .hdrsize = 0,
	1095	+ .maxattr = GTPA_MAX,
	1096	+ .netnsok = true,
	1097	+};
	1098	+
	1099	+static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
	1100	+ u32 type, struct pdp_ctx *pctx)
	1101	+{
	1102	+ void *genlh;
	1103	+
	1104	+ genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
	1105	+ type);
	1106	+ if (genlh == NULL)
	1107	+ goto nlmsg_failure;
	1108	+
	1109	+ if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) \|\|
	1110	+ nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) \|\|
	1111	+ nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
	1112	+ goto nla_put_failure;
	1113	+
	1114	+ switch (pctx->gtp_version) {
	1115	+ case GTP_V0:
	1116	+ if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) \|\|
	1117	+ nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
	1118	+ goto nla_put_failure;
	1119	+ break;
	1120	+ case GTP_V1:
	1121	+ if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) \|\|
	1122	+ nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
	1123	+ goto nla_put_failure;
	1124	+ break;
	1125	+ }
	1126	+ genlmsg_end(skb, genlh);
	1127	+ return 0;
	1128	+
	1129	+nlmsg_failure:
	1130	+nla_put_failure:
	1131	+ genlmsg_cancel(skb, genlh);
	1132	+ return -EMSGSIZE;
	1133	+}
	1134	+
	1135	+static int gtp_genl_get_pdp(struct sk_buff skb, struct genl_info info)
	1136	+{
	1137	+ struct pdp_ctx *pctx = NULL;
	1138	+ struct net_device *dev;
	1139	+ struct sk_buff *skb2;
	1140	+ struct gtp_dev *gtp;
	1141	+ u32 gtp_version;
	1142	+ struct net *net;
	1143	+ int err;
	1144	+
	1145	+ if (!info->attrs[GTPA_VERSION] \|\|
	1146	+ !info->attrs[GTPA_LINK])
	1147	+ return -EINVAL;
	1148	+
	1149	+ gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
	1150	+ switch (gtp_version) {
	1151	+ case GTP_V0:
	1152	+ case GTP_V1:
	1153	+ break;
	1154	+ default:
	1155	+ return -EINVAL;
	1156	+ }
	1157	+
	1158	+ net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
	1159	+ if (IS_ERR(net))
	1160	+ return PTR_ERR(net);
	1161	+
	1162	+ /* Check if there's an existing gtpX device to configure */
	1163	+ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
	1164	+ if (dev == NULL)
	1165	+ return -ENODEV;
	1166	+
	1167	+ gtp = netdev_priv(dev);
	1168	+
	1169	+ rcu_read_lock();
	1170	+ if (gtp_version == GTP_V0 &&
	1171	+ info->attrs[GTPA_TID]) {
	1172	+ u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
	1173	+
	1174	+ pctx = gtp0_pdp_find(gtp, tid);
	1175	+ } else if (gtp_version == GTP_V1 &&
	1176	+ info->attrs[GTPA_I_TEI]) {
	1177	+ u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
	1178	+
	1179	+ pctx = gtp1_pdp_find(gtp, tid);
	1180	+ } else if (info->attrs[GTPA_MS_ADDRESS]) {
	1181	+ __be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
	1182	+
	1183	+ pctx = ipv4_pdp_find(gtp, ip);
	1184	+ }
	1185	+
	1186	+ if (pctx == NULL) {
	1187	+ err = -ENOENT;
	1188	+ goto err_unlock;
	1189	+ }
	1190	+
	1191	+ skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
	1192	+ if (skb2 == NULL) {
	1193	+ err = -ENOMEM;
	1194	+ goto err_unlock;
	1195	+ }
	1196	+
	1197	+ err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
	1198	+ info->snd_seq, info->nlhdr->nlmsg_type, pctx);
	1199	+ if (err < 0)
	1200	+ goto err_unlock_free;
	1201	+
	1202	+ rcu_read_unlock();
	1203	+ return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
	1204	+
	1205	+err_unlock_free:
	1206	+ kfree_skb(skb2);
	1207	+err_unlock:
	1208	+ rcu_read_unlock();
	1209	+ return err;
	1210	+}
	1211	+
	1212	+static int gtp_genl_dump_pdp(struct sk_buff *skb,
	1213	+ struct netlink_callback *cb)
	1214	+{
	1215	+ struct gtp_dev last_gtp = (struct gtp_dev )cb->args[2], *gtp;
	1216	+ struct net *net = sock_net(skb->sk);
	1217	+ struct gtp_net *gn = net_generic(net, gtp_net_id);
	1218	+ unsigned long tid = cb->args[1];
	1219	+ int i, k = cb->args[0], ret;
	1220	+ struct pdp_ctx *pctx;
	1221	+
	1222	+ if (cb->args[4])
	1223	+ return 0;
	1224	+
	1225	+ list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
	1226	+ if (last_gtp && last_gtp != gtp)
	1227	+ continue;
	1228	+ else
	1229	+ last_gtp = NULL;
	1230	+
	1231	+ for (i = k; i < gtp->hash_size; i++) {
	1232	+ hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
	1233	+ if (tid && tid != pctx->u.tid)
	1234	+ continue;
	1235	+ else
	1236	+ tid = 0;
	1237	+
	1238	+ ret = gtp_genl_fill_info(skb,
	1239	+ NETLINK_CB(cb->skb).portid,
	1240	+ cb->nlh->nlmsg_seq,
	1241	+ cb->nlh->nlmsg_type, pctx);
	1242	+ if (ret < 0) {
	1243	+ cb->args[0] = i;
	1244	+ cb->args[1] = pctx->u.tid;
	1245	+ cb->args[2] = (unsigned long)gtp;
	1246	+ goto out;
	1247	+ }
	1248	+ }
	1249	+ }
	1250	+ }
	1251	+ cb->args[4] = 1;
	1252	+out:
	1253	+ return skb->len;
	1254	+}
	1255	+
	1256	+static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
	1257	+ [GTPA_LINK] = { .type = NLA_U32, },
	1258	+ [GTPA_VERSION] = { .type = NLA_U32, },
	1259	+ [GTPA_TID] = { .type = NLA_U64, },
	1260	+ [GTPA_SGSN_ADDRESS] = { .type = NLA_U32, },
	1261	+ [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
	1262	+ [GTPA_FLOW] = { .type = NLA_U16, },
	1263	+ [GTPA_NET_NS_FD] = { .type = NLA_U32, },
	1264	+ [GTPA_I_TEI] = { .type = NLA_U32, },
	1265	+ [GTPA_O_TEI] = { .type = NLA_U32, },
	1266	+};
	1267	+
	1268	+static const struct genl_ops gtp_genl_ops[] = {
	1269	+ {
	1270	+ .cmd = GTP_CMD_NEWPDP,
	1271	+ .doit = gtp_genl_new_pdp,
	1272	+ .policy = gtp_genl_policy,
	1273	+ .flags = GENL_ADMIN_PERM,
	1274	+ },
	1275	+ {
	1276	+ .cmd = GTP_CMD_DELPDP,
	1277	+ .doit = gtp_genl_del_pdp,
	1278	+ .policy = gtp_genl_policy,
	1279	+ .flags = GENL_ADMIN_PERM,
	1280	+ },
	1281	+ {
	1282	+ .cmd = GTP_CMD_GETPDP,
	1283	+ .doit = gtp_genl_get_pdp,
	1284	+ .dumpit = gtp_genl_dump_pdp,
	1285	+ .policy = gtp_genl_policy,
	1286	+ .flags = GENL_ADMIN_PERM,
	1287	+ },
	1288	+};
	1289	+
	1290	+static int __net_init gtp_net_init(struct net *net)
	1291	+{
	1292	+ struct gtp_net *gn = net_generic(net, gtp_net_id);
	1293	+
	1294	+ INIT_LIST_HEAD(&gn->gtp_dev_list);
	1295	+ return 0;
	1296	+}
	1297	+
	1298	+static void __net_exit gtp_net_exit(struct net *net)
	1299	+{
	1300	+ struct gtp_net *gn = net_generic(net, gtp_net_id);
	1301	+ struct gtp_dev *gtp;
	1302	+ LIST_HEAD(list);
	1303	+
	1304	+ rtnl_lock();
	1305	+ list_for_each_entry(gtp, &gn->gtp_dev_list, list)
	1306	+ gtp_dellink(gtp->dev, &list);
	1307	+
	1308	+ unregister_netdevice_many(&list);
	1309	+ rtnl_unlock();
	1310	+}
	1311	+
	1312	+static struct pernet_operations gtp_net_ops = {
	1313	+ .init = gtp_net_init,
	1314	+ .exit = gtp_net_exit,
	1315	+ .id = &gtp_net_id,
	1316	+ .size = sizeof(struct gtp_net),
	1317	+};
	1318	+
	1319	+static int __init gtp_init(void)
	1320	+{
	1321	+ int err;
	1322	+
	1323	+ get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
	1324	+
	1325	+ err = rtnl_link_register(&gtp_link_ops);
	1326	+ if (err < 0)
	1327	+ goto error_out;
	1328	+
	1329	+ err = genl_register_family_with_ops(&gtp_genl_family, gtp_genl_ops);
	1330	+ if (err < 0)
	1331	+ goto unreg_rtnl_link;
	1332	+
	1333	+ err = register_pernet_subsys(&gtp_net_ops);
	1334	+ if (err < 0)
	1335	+ goto unreg_genl_family;
	1336	+
	1337	+ pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n",
	1338	+ sizeof(struct pdp_ctx));
	1339	+ return 0;
	1340	+
	1341	+unreg_genl_family:
	1342	+ genl_unregister_family(&gtp_genl_family);
	1343	+unreg_rtnl_link:
	1344	+ rtnl_link_unregister(&gtp_link_ops);
	1345	+error_out:
	1346	+ pr_err("error loading GTP module loaded\n");
	1347	+ return err;
	1348	+}
	1349	+late_initcall(gtp_init);
	1350	+
	1351	+static void __exit gtp_fini(void)
	1352	+{
	1353	+ unregister_pernet_subsys(&gtp_net_ops);
	1354	+ genl_unregister_family(&gtp_genl_family);
	1355	+ rtnl_link_unregister(&gtp_link_ops);
	1356	+
	1357	+ pr_info("GTP module unloaded\n");
	1358	+}
	1359	+module_exit(gtp_fini);
	1360	+
	1361	+MODULE_LICENSE("GPL");
	1362	+MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
	1363	+MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
	1364	+MODULE_ALIAS_RTNL_LINK("gtp");

include/net/gtp.h+34−0

@@ -0,0 +1,34 @@
	1	+#ifndef _GTP_H_
	2	+#define _GTP_H
	3	+
	4	+/* General GTP protocol related definitions. */
	5	+
	6	+#define GTP0_PORT 3386
	7	+#define GTP1U_PORT 2152
	8	+
	9	+#define GTP_TPDU 255
	10	+
	11	+struct gtp0_header { /* According to GSM TS 09.60. */
	12	+ __u8 flags;
	13	+ __u8 type;
	14	+ __be16 length;
	15	+ __be16 seq;
	16	+ __be16 flow;
	17	+ __u8 number;
	18	+ __u8 spare[3];
	19	+ __be64 tid;
	20	+} __attribute__ ((packed));
	21	+
	22	+struct gtp1_header { /* According to 3GPP TS 29.060. */
	23	+ __u8 flags;
	24	+ __u8 type;
	25	+ __be16 length;
	26	+ __be32 tid;
	27	+} __attribute__ ((packed));
	28	+
	29	+#define GTP1_F_NPDU 0x01
	30	+#define GTP1_F_SEQ 0x02
	31	+#define GTP1_F_EXTHDR 0x04
	32	+#define GTP1_F_MASK 0x07
	33	+
	34	+#endif

include/uapi/linux/Kbuild+1−0

@@ -141,6 +141,7 @@ header-y += gfs2_ondisk.h · 140 unmodified lines
141	141	header-y += gigaset_dev.h
142	142	header-y += gpio.h
143	143	header-y += gsmmux.h
	144	+header-y += gtp.h
144	145	header-y += hdlcdrv.h
145	146	header-y += hdlc.h
146	147	header-y += hdreg.h

include/uapi/linux/gtp.h+33−0

@@ -0,0 +1,33 @@
	1	+#ifndef _UAPI_LINUX_GTP_H_
	2	+#define _UAPI_LINUX_GTP_H__
	3	+
	4	+enum gtp_genl_cmds {
	5	+ GTP_CMD_NEWPDP,
	6	+ GTP_CMD_DELPDP,
	7	+ GTP_CMD_GETPDP,
	8	+
	9	+ GTP_CMD_MAX,
	10	+};
	11	+
	12	+enum gtp_version {
	13	+ GTP_V0 = 0,
	14	+ GTP_V1,
	15	+};
	16	+
	17	+enum gtp_attrs {
	18	+ GTPA_UNSPEC = 0,
	19	+ GTPA_LINK,
	20	+ GTPA_VERSION,
	21	+ GTPA_TID, /* for GTPv0 only */
	22	+ GTPA_SGSN_ADDRESS,
	23	+ GTPA_MS_ADDRESS,
	24	+ GTPA_FLOW,
	25	+ GTPA_NET_NS_FD,
	26	+ GTPA_I_TEI, /* for GTPv1 only */
	27	+ GTPA_O_TEI, /* for GTPv1 only */
	28	+ GTPA_PAD,
	29	+ __GTPA_MAX,
	30	+};
	31	+#define GTPA_MAX (__GTPA_MAX + 1)
	32	+
	33	+#endif /* _UAPI_LINUX_GTP_H_ */

include/uapi/linux/if_link.h+10−0

@@ -529,6 +529,16 @@ enum { · 528 unmodified lines
529	529	};
530	530	#define IFLA_PPP_MAX (__IFLA_PPP_MAX - 1)
531	531
	532	+/* GTP section */
	533	+enum {
	534	+ IFLA_GTP_UNSPEC,
	535	+ IFLA_GTP_FD0,
	536	+ IFLA_GTP_FD1,
	537	+ IFLA_GTP_PDP_HASHSIZE,
	538	+ __IFLA_GTP_MAX,
	539	+};
	540	+#define IFLA_GTP_MAX (__IFLA_GTP_MAX - 1)
	541	+
532	542	/* Bonding section */
533	543
534	544	enum {

include/uapi/linux/udp.h+2−1

@@ -36,6 +36,7 @@ struct udphdr { · 35 unmodified lines
36	36	#define UDP_ENCAP_ESPINUDP_NON_IKE 1 /* draft-ietf-ipsec-nat-t-ike-00/01 */
37	37	#define UDP_ENCAP_ESPINUDP 2 /* draft-ietf-ipsec-udp-encaps-06 */
38	38	#define UDP_ENCAP_L2TPINUDP 3 /* rfc2661 */
39		−
	39	+#define UDP_ENCAP_GTP0 4 /* GSM TS 09.60 */
	40	+#define UDP_ENCAP_GTP1U 5 /* 3GPP TS 29.060 */
40	41
41	42	#endif /* _UAPI_LINUX_UDP_H */