linux/drivers/net/gtp.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* GTP according to GSM TS 09.60 / 3GPP TS 29.060
   3 *
   4 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
   5 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
   6 *
   7 * Author: Harald Welte <hwelte@sysmocom.de>
   8 *         Pablo Neira Ayuso <pablo@netfilter.org>
   9 *         Andreas Schultz <aschultz@travelping.com>
  10 */
  11
  12#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  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>
  23
  24#include <net/net_namespace.h>
  25#include <net/protocol.h>
  26#include <net/ip.h>
  27#include <net/udp.h>
  28#include <net/udp_tunnel.h>
  29#include <net/icmp.h>
  30#include <net/xfrm.h>
  31#include <net/genetlink.h>
  32#include <net/netns/generic.h>
  33#include <net/gtp.h>
  34
  35/* An active session for the subscriber. */
  36struct pdp_ctx {
  37        struct hlist_node       hlist_tid;
  38        struct hlist_node       hlist_addr;
  39
  40        union {
  41                u64             tid;
  42                struct {
  43                        u64     tid;
  44                        u16     flow;
  45                } v0;
  46                struct {
  47                        u32     i_tei;
  48                        u32     o_tei;
  49                } v1;
  50        } u;
  51        u8                      gtp_version;
  52        u16                     af;
  53
  54        struct in_addr          ms_addr_ip4;
  55        struct in_addr          peer_addr_ip4;
  56
  57        struct sock             *sk;
  58        struct net_device       *dev;
  59
  60        atomic_t                tx_seq;
  61        struct rcu_head         rcu_head;
  62};
  63
  64/* One instance of the GTP device. */
  65struct gtp_dev {
  66        struct list_head        list;
  67
  68        struct sock             *sk0;
  69        struct sock             *sk1u;
  70
  71        struct net_device       *dev;
  72
  73        unsigned int            role;
  74        unsigned int            hash_size;
  75        struct hlist_head       *tid_hash;
  76        struct hlist_head       *addr_hash;
  77};
  78
  79static unsigned int gtp_net_id __read_mostly;
  80
  81struct gtp_net {
  82        struct list_head gtp_dev_list;
  83};
  84
  85static u32 gtp_h_initval;
  86
  87static void pdp_context_delete(struct pdp_ctx *pctx);
  88
  89static 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
  95static inline u32 gtp1u_hashfn(u32 tid)
  96{
  97        return jhash_1word(tid, gtp_h_initval);
  98}
  99
 100static 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. */
 106static 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. */
 122static 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. */
 138static 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
 154static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
 155                                  unsigned int hdrlen, unsigned int role)
 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);
 163
 164        if (role == GTP_ROLE_SGSN)
 165                return iph->daddr == pctx->ms_addr_ip4.s_addr;
 166        else
 167                return iph->saddr == pctx->ms_addr_ip4.s_addr;
 168}
 169
 170/* Check if the inner IP address in this packet is assigned to any
 171 * existing mobile subscriber.
 172 */
 173static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
 174                             unsigned int hdrlen, unsigned int role)
 175{
 176        switch (ntohs(skb->protocol)) {
 177        case ETH_P_IP:
 178                return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
 179        }
 180        return false;
 181}
 182
 183static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
 184                        unsigned int hdrlen, unsigned int role)
 185{
 186        struct pcpu_sw_netstats *stats;
 187
 188        if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
 189                netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
 190                return 1;
 191        }
 192
 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))))
 196                return -1;
 197
 198        netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
 199
 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.
 203         */
 204        skb_reset_network_header(skb);
 205
 206        skb->dev = pctx->dev;
 207
 208        stats = this_cpu_ptr(pctx->dev->tstats);
 209        u64_stats_update_begin(&stats->syncp);
 210        stats->rx_packets++;
 211        stats->rx_bytes += skb->len;
 212        u64_stats_update_end(&stats->syncp);
 213
 214        netif_rx(skb);
 215        return 0;
 216}
 217
 218/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
 219static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 220{
 221        unsigned int hdrlen = sizeof(struct udphdr) +
 222                              sizeof(struct gtp0_header);
 223        struct gtp0_header *gtp0;
 224        struct pdp_ctx *pctx;
 225
 226        if (!pskb_may_pull(skb, hdrlen))
 227                return -1;
 228
 229        gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
 230
 231        if ((gtp0->flags >> 5) != GTP_V0)
 232                return 1;
 233
 234        if (gtp0->type != GTP_TPDU)
 235                return 1;
 236
 237        pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
 238        if (!pctx) {
 239                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
 240                return 1;
 241        }
 242
 243        return gtp_rx(pctx, skb, hdrlen, gtp->role);
 244}
 245
 246static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
 247{
 248        unsigned int hdrlen = sizeof(struct udphdr) +
 249                              sizeof(struct gtp1_header);
 250        struct gtp1_header *gtp1;
 251        struct pdp_ctx *pctx;
 252
 253        if (!pskb_may_pull(skb, hdrlen))
 254                return -1;
 255
 256        gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 257
 258        if ((gtp1->flags >> 5) != GTP_V1)
 259                return 1;
 260
 261        if (gtp1->type != GTP_TPDU)
 262                return 1;
 263
 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.".
 266         *
 267         * If any of the bit is set, then the remaining ones also have to be
 268         * set.
 269         */
 270        if (gtp1->flags & GTP1_F_MASK)
 271                hdrlen += 4;
 272
 273        /* Make sure the header is larger enough, including extensions. */
 274        if (!pskb_may_pull(skb, hdrlen))
 275                return -1;
 276
 277        gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
 278
 279        pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
 280        if (!pctx) {
 281                netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
 282                return 1;
 283        }
 284
 285        return gtp_rx(pctx, skb, hdrlen, gtp->role);
 286}
 287
 288static void gtp_encap_destroy(struct sock *sk)
 289{
 290        struct gtp_dev *gtp;
 291
 292        gtp = rcu_dereference_sk_user_data(sk);
 293        if (gtp) {
 294                udp_sk(sk)->encap_type = 0;
 295                rcu_assign_sk_user_data(sk, NULL);
 296                sock_put(sk);
 297        }
 298}
 299
 300static void gtp_encap_disable_sock(struct sock *sk)
 301{
 302        if (!sk)
 303                return;
 304
 305        gtp_encap_destroy(sk);
 306}
 307
 308static void gtp_encap_disable(struct gtp_dev *gtp)
 309{
 310        gtp_encap_disable_sock(gtp->sk0);
 311        gtp_encap_disable_sock(gtp->sk1u);
 312}
 313
 314/* UDP encapsulation receive handler. See net/ipv4/udp.c.
 315 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
 316 */
 317static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 318{
 319        struct gtp_dev *gtp;
 320        int ret = 0;
 321
 322        gtp = rcu_dereference_sk_user_data(sk);
 323        if (!gtp)
 324                return 1;
 325
 326        netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
 327
 328        switch (udp_sk(sk)->encap_type) {
 329        case UDP_ENCAP_GTP0:
 330                netdev_dbg(gtp->dev, "received GTP0 packet\n");
 331                ret = gtp0_udp_encap_recv(gtp, skb);
 332                break;
 333        case UDP_ENCAP_GTP1U:
 334                netdev_dbg(gtp->dev, "received GTP1U packet\n");
 335                ret = gtp1u_udp_encap_recv(gtp, skb);
 336                break;
 337        default:
 338                ret = -1; /* Shouldn't happen. */
 339        }
 340
 341        switch (ret) {
 342        case 1:
 343                netdev_dbg(gtp->dev, "pass up to the process\n");
 344                break;
 345        case 0:
 346                break;
 347        case -1:
 348                netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
 349                kfree_skb(skb);
 350                ret = 0;
 351                break;
 352        }
 353
 354        return ret;
 355}
 356
 357static int gtp_dev_init(struct net_device *dev)
 358{
 359        struct gtp_dev *gtp = netdev_priv(dev);
 360
 361        gtp->dev = dev;
 362
 363        dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 364        if (!dev->tstats)
 365                return -ENOMEM;
 366
 367        return 0;
 368}
 369
 370static void gtp_dev_uninit(struct net_device *dev)
 371{
 372        struct gtp_dev *gtp = netdev_priv(dev);
 373
 374        gtp_encap_disable(gtp);
 375        free_percpu(dev->tstats);
 376}
 377
 378static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
 379                                           const struct sock *sk,
 380                                           __be32 daddr)
 381{
 382        memset(fl4, 0, sizeof(*fl4));
 383        fl4->flowi4_oif         = sk->sk_bound_dev_if;
 384        fl4->daddr              = daddr;
 385        fl4->saddr              = inet_sk(sk)->inet_saddr;
 386        fl4->flowi4_tos         = RT_CONN_FLAGS(sk);
 387        fl4->flowi4_proto       = sk->sk_protocol;
 388
 389        return ip_route_output_key(sock_net(sk), fl4);
 390}
 391
 392static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 393{
 394        int payload_len = skb->len;
 395        struct gtp0_header *gtp0;
 396
 397        gtp0 = skb_push(skb, sizeof(*gtp0));
 398
 399        gtp0->flags     = 0x1e; /* v0, GTP-non-prime. */
 400        gtp0->type      = GTP_TPDU;
 401        gtp0->length    = htons(payload_len);
 402        gtp0->seq       = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
 403        gtp0->flow      = htons(pctx->u.v0.flow);
 404        gtp0->number    = 0xff;
 405        gtp0->spare[0]  = gtp0->spare[1] = gtp0->spare[2] = 0xff;
 406        gtp0->tid       = cpu_to_be64(pctx->u.v0.tid);
 407}
 408
 409static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 410{
 411        int payload_len = skb->len;
 412        struct gtp1_header *gtp1;
 413
 414        gtp1 = skb_push(skb, sizeof(*gtp1));
 415
 416        /* Bits    8  7  6  5  4  3  2  1
 417         *        +--+--+--+--+--+--+--+--+
 418         *        |version |PT| 0| E| S|PN|
 419         *        +--+--+--+--+--+--+--+--+
 420         *          0  0  1  1  1  0  0  0
 421         */
 422        gtp1->flags     = 0x30; /* v1, GTP-non-prime. */
 423        gtp1->type      = GTP_TPDU;
 424        gtp1->length    = htons(payload_len);
 425        gtp1->tid       = htonl(pctx->u.v1.o_tei);
 426
 427        /* TODO: Suppport for extension header, sequence number and N-PDU.
 428         *       Update the length field if any of them is available.
 429         */
 430}
 431
 432struct gtp_pktinfo {
 433        struct sock             *sk;
 434        struct iphdr            *iph;
 435        struct flowi4           fl4;
 436        struct rtable           *rt;
 437        struct pdp_ctx          *pctx;
 438        struct net_device       *dev;
 439        __be16                  gtph_port;
 440};
 441
 442static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
 443{
 444        switch (pktinfo->pctx->gtp_version) {
 445        case GTP_V0:
 446                pktinfo->gtph_port = htons(GTP0_PORT);
 447                gtp0_push_header(skb, pktinfo->pctx);
 448                break;
 449        case GTP_V1:
 450                pktinfo->gtph_port = htons(GTP1U_PORT);
 451                gtp1_push_header(skb, pktinfo->pctx);
 452                break;
 453        }
 454}
 455
 456static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
 457                                        struct sock *sk, struct iphdr *iph,
 458                                        struct pdp_ctx *pctx, struct rtable *rt,
 459                                        struct flowi4 *fl4,
 460                                        struct net_device *dev)
 461{
 462        pktinfo->sk     = sk;
 463        pktinfo->iph    = iph;
 464        pktinfo->pctx   = pctx;
 465        pktinfo->rt     = rt;
 466        pktinfo->fl4    = *fl4;
 467        pktinfo->dev    = dev;
 468}
 469
 470static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 471                             struct gtp_pktinfo *pktinfo)
 472{
 473        struct gtp_dev *gtp = netdev_priv(dev);
 474        struct pdp_ctx *pctx;
 475        struct rtable *rt;
 476        struct flowi4 fl4;
 477        struct iphdr *iph;
 478        __be16 df;
 479        int mtu;
 480
 481        /* Read the IP destination address and resolve the PDP context.
 482         * Prepend PDP header with TEI/TID from PDP ctx.
 483         */
 484        iph = ip_hdr(skb);
 485        if (gtp->role == GTP_ROLE_SGSN)
 486                pctx = ipv4_pdp_find(gtp, iph->saddr);
 487        else
 488                pctx = ipv4_pdp_find(gtp, iph->daddr);
 489
 490        if (!pctx) {
 491                netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
 492                           &iph->daddr);
 493                return -ENOENT;
 494        }
 495        netdev_dbg(dev, "found PDP context %p\n", pctx);
 496
 497        rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
 498        if (IS_ERR(rt)) {
 499                netdev_dbg(dev, "no route to SSGN %pI4\n",
 500                           &pctx->peer_addr_ip4.s_addr);
 501                dev->stats.tx_carrier_errors++;
 502                goto err;
 503        }
 504
 505        if (rt->dst.dev == dev) {
 506                netdev_dbg(dev, "circular route to SSGN %pI4\n",
 507                           &pctx->peer_addr_ip4.s_addr);
 508                dev->stats.collisions++;
 509                goto err_rt;
 510        }
 511
 512        skb_dst_drop(skb);
 513
 514        /* This is similar to tnl_update_pmtu(). */
 515        df = iph->frag_off;
 516        if (df) {
 517                mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
 518                        sizeof(struct iphdr) - sizeof(struct udphdr);
 519                switch (pctx->gtp_version) {
 520                case GTP_V0:
 521                        mtu -= sizeof(struct gtp0_header);
 522                        break;
 523                case GTP_V1:
 524                        mtu -= sizeof(struct gtp1_header);
 525                        break;
 526                }
 527        } else {
 528                mtu = dst_mtu(&rt->dst);
 529        }
 530
 531        rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
 532
 533        if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
 534            mtu < ntohs(iph->tot_len)) {
 535                netdev_dbg(dev, "packet too big, fragmentation needed\n");
 536                memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 537                icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 538                          htonl(mtu));
 539                goto err_rt;
 540        }
 541
 542        gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
 543        gtp_push_header(skb, pktinfo);
 544
 545        return 0;
 546err_rt:
 547        ip_rt_put(rt);
 548err:
 549        return -EBADMSG;
 550}
 551
 552static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 553{
 554        unsigned int proto = ntohs(skb->protocol);
 555        struct gtp_pktinfo pktinfo;
 556        int err;
 557
 558        /* Ensure there is sufficient headroom. */
 559        if (skb_cow_head(skb, dev->needed_headroom))
 560                goto tx_err;
 561
 562        skb_reset_inner_headers(skb);
 563
 564        /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
 565        rcu_read_lock();
 566        switch (proto) {
 567        case ETH_P_IP:
 568                err = gtp_build_skb_ip4(skb, dev, &pktinfo);
 569                break;
 570        default:
 571                err = -EOPNOTSUPP;
 572                break;
 573        }
 574        rcu_read_unlock();
 575
 576        if (err < 0)
 577                goto tx_err;
 578
 579        switch (proto) {
 580        case ETH_P_IP:
 581                netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
 582                           &pktinfo.iph->saddr, &pktinfo.iph->daddr);
 583                udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
 584                                    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
 585                                    pktinfo.iph->tos,
 586                                    ip4_dst_hoplimit(&pktinfo.rt->dst),
 587                                    0,
 588                                    pktinfo.gtph_port, pktinfo.gtph_port,
 589                                    true, false);
 590                break;
 591        }
 592
 593        return NETDEV_TX_OK;
 594tx_err:
 595        dev->stats.tx_errors++;
 596        dev_kfree_skb(skb);
 597        return NETDEV_TX_OK;
 598}
 599
 600static const struct net_device_ops gtp_netdev_ops = {
 601        .ndo_init               = gtp_dev_init,
 602        .ndo_uninit             = gtp_dev_uninit,
 603        .ndo_start_xmit         = gtp_dev_xmit,
 604        .ndo_get_stats64        = ip_tunnel_get_stats64,
 605};
 606
 607static void gtp_link_setup(struct net_device *dev)
 608{
 609        dev->netdev_ops         = &gtp_netdev_ops;
 610        dev->needs_free_netdev  = true;
 611
 612        dev->hard_header_len = 0;
 613        dev->addr_len = 0;
 614
 615        /* Zero header length. */
 616        dev->type = ARPHRD_NONE;
 617        dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 618
 619        dev->priv_flags |= IFF_NO_QUEUE;
 620        dev->features   |= NETIF_F_LLTX;
 621        netif_keep_dst(dev);
 622
 623        /* Assume largest header, ie. GTPv0. */
 624        dev->needed_headroom    = LL_MAX_HEADER +
 625                                  sizeof(struct iphdr) +
 626                                  sizeof(struct udphdr) +
 627                                  sizeof(struct gtp0_header);
 628}
 629
 630static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
 631static void gtp_hashtable_free(struct gtp_dev *gtp);
 632static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
 633
 634static int gtp_newlink(struct net *src_net, struct net_device *dev,
 635                       struct nlattr *tb[], struct nlattr *data[],
 636                       struct netlink_ext_ack *extack)
 637{
 638        struct gtp_dev *gtp;
 639        struct gtp_net *gn;
 640        int hashsize, err;
 641
 642        if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
 643                return -EINVAL;
 644
 645        gtp = netdev_priv(dev);
 646
 647        err = gtp_encap_enable(gtp, data);
 648        if (err < 0)
 649                return err;
 650
 651        if (!data[IFLA_GTP_PDP_HASHSIZE])
 652                hashsize = 1024;
 653        else
 654                hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
 655
 656        err = gtp_hashtable_new(gtp, hashsize);
 657        if (err < 0)
 658                goto out_encap;
 659
 660        err = register_netdevice(dev);
 661        if (err < 0) {
 662                netdev_dbg(dev, "failed to register new netdev %d\n", err);
 663                goto out_hashtable;
 664        }
 665
 666        gn = net_generic(dev_net(dev), gtp_net_id);
 667        list_add_rcu(&gtp->list, &gn->gtp_dev_list);
 668
 669        netdev_dbg(dev, "registered new GTP interface\n");
 670
 671        return 0;
 672
 673out_hashtable:
 674        gtp_hashtable_free(gtp);
 675out_encap:
 676        gtp_encap_disable(gtp);
 677        return err;
 678}
 679
 680static void gtp_dellink(struct net_device *dev, struct list_head *head)
 681{
 682        struct gtp_dev *gtp = netdev_priv(dev);
 683
 684        gtp_encap_disable(gtp);
 685        gtp_hashtable_free(gtp);
 686        list_del_rcu(&gtp->list);
 687        unregister_netdevice_queue(dev, head);
 688}
 689
 690static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
 691        [IFLA_GTP_FD0]                  = { .type = NLA_U32 },
 692        [IFLA_GTP_FD1]                  = { .type = NLA_U32 },
 693        [IFLA_GTP_PDP_HASHSIZE]         = { .type = NLA_U32 },
 694        [IFLA_GTP_ROLE]                 = { .type = NLA_U32 },
 695};
 696
 697static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
 698                        struct netlink_ext_ack *extack)
 699{
 700        if (!data)
 701                return -EINVAL;
 702
 703        return 0;
 704}
 705
 706static size_t gtp_get_size(const struct net_device *dev)
 707{
 708        return nla_total_size(sizeof(__u32));   /* IFLA_GTP_PDP_HASHSIZE */
 709}
 710
 711static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 712{
 713        struct gtp_dev *gtp = netdev_priv(dev);
 714
 715        if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
 716                goto nla_put_failure;
 717
 718        return 0;
 719
 720nla_put_failure:
 721        return -EMSGSIZE;
 722}
 723
 724static struct rtnl_link_ops gtp_link_ops __read_mostly = {
 725        .kind           = "gtp",
 726        .maxtype        = IFLA_GTP_MAX,
 727        .policy         = gtp_policy,
 728        .priv_size      = sizeof(struct gtp_dev),
 729        .setup          = gtp_link_setup,
 730        .validate       = gtp_validate,
 731        .newlink        = gtp_newlink,
 732        .dellink        = gtp_dellink,
 733        .get_size       = gtp_get_size,
 734        .fill_info      = gtp_fill_info,
 735};
 736
 737static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
 738{
 739        int i;
 740
 741        gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
 742                                       GFP_KERNEL);
 743        if (gtp->addr_hash == NULL)
 744                return -ENOMEM;
 745
 746        gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
 747                                      GFP_KERNEL);
 748        if (gtp->tid_hash == NULL)
 749                goto err1;
 750
 751        gtp->hash_size = hsize;
 752
 753        for (i = 0; i < hsize; i++) {
 754                INIT_HLIST_HEAD(&gtp->addr_hash[i]);
 755                INIT_HLIST_HEAD(&gtp->tid_hash[i]);
 756        }
 757        return 0;
 758err1:
 759        kfree(gtp->addr_hash);
 760        return -ENOMEM;
 761}
 762
 763static void gtp_hashtable_free(struct gtp_dev *gtp)
 764{
 765        struct pdp_ctx *pctx;
 766        int i;
 767
 768        for (i = 0; i < gtp->hash_size; i++)
 769                hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
 770                        pdp_context_delete(pctx);
 771
 772        synchronize_rcu();
 773        kfree(gtp->addr_hash);
 774        kfree(gtp->tid_hash);
 775}
 776
 777static struct sock *gtp_encap_enable_socket(int fd, int type,
 778                                            struct gtp_dev *gtp)
 779{
 780        struct udp_tunnel_sock_cfg tuncfg = {NULL};
 781        struct socket *sock;
 782        struct sock *sk;
 783        int err;
 784
 785        pr_debug("enable gtp on %d, %d\n", fd, type);
 786
 787        sock = sockfd_lookup(fd, &err);
 788        if (!sock) {
 789                pr_debug("gtp socket fd=%d not found\n", fd);
 790                return NULL;
 791        }
 792
 793        if (sock->sk->sk_protocol != IPPROTO_UDP) {
 794                pr_debug("socket fd=%d not UDP\n", fd);
 795                sk = ERR_PTR(-EINVAL);
 796                goto out_sock;
 797        }
 798
 799        if (rcu_dereference_sk_user_data(sock->sk)) {
 800                sk = ERR_PTR(-EBUSY);
 801                goto out_sock;
 802        }
 803
 804        sk = sock->sk;
 805        sock_hold(sk);
 806
 807        tuncfg.sk_user_data = gtp;
 808        tuncfg.encap_type = type;
 809        tuncfg.encap_rcv = gtp_encap_recv;
 810        tuncfg.encap_destroy = gtp_encap_destroy;
 811
 812        setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
 813
 814out_sock:
 815        sockfd_put(sock);
 816        return sk;
 817}
 818
 819static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
 820{
 821        struct sock *sk1u = NULL;
 822        struct sock *sk0 = NULL;
 823        unsigned int role = GTP_ROLE_GGSN;
 824
 825        if (data[IFLA_GTP_FD0]) {
 826                u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
 827
 828                sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
 829                if (IS_ERR(sk0))
 830                        return PTR_ERR(sk0);
 831        }
 832
 833        if (data[IFLA_GTP_FD1]) {
 834                u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
 835
 836                sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
 837                if (IS_ERR(sk1u)) {
 838                        if (sk0)
 839                                gtp_encap_disable_sock(sk0);
 840                        return PTR_ERR(sk1u);
 841                }
 842        }
 843
 844        if (data[IFLA_GTP_ROLE]) {
 845                role = nla_get_u32(data[IFLA_GTP_ROLE]);
 846                if (role > GTP_ROLE_SGSN)
 847                        return -EINVAL;
 848        }
 849
 850        gtp->sk0 = sk0;
 851        gtp->sk1u = sk1u;
 852        gtp->role = role;
 853
 854        return 0;
 855}
 856
 857static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
 858{
 859        struct gtp_dev *gtp = NULL;
 860        struct net_device *dev;
 861        struct net *net;
 862
 863        /* Examine the link attributes and figure out which network namespace
 864         * we are talking about.
 865         */
 866        if (nla[GTPA_NET_NS_FD])
 867                net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
 868        else
 869                net = get_net(src_net);
 870
 871        if (IS_ERR(net))
 872                return NULL;
 873
 874        /* Check if there's an existing gtpX device to configure */
 875        dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
 876        if (dev && dev->netdev_ops == &gtp_netdev_ops)
 877                gtp = netdev_priv(dev);
 878
 879        put_net(net);
 880        return gtp;
 881}
 882
 883static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
 884{
 885        pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
 886        pctx->af = AF_INET;
 887        pctx->peer_addr_ip4.s_addr =
 888                nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
 889        pctx->ms_addr_ip4.s_addr =
 890                nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
 891
 892        switch (pctx->gtp_version) {
 893        case GTP_V0:
 894                /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
 895                 * label needs to be the same for uplink and downlink packets,
 896                 * so let's annotate this.
 897                 */
 898                pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
 899                pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
 900                break;
 901        case GTP_V1:
 902                pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
 903                pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
 904                break;
 905        default:
 906                break;
 907        }
 908}
 909
 910static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
 911                        struct genl_info *info)
 912{
 913        struct net_device *dev = gtp->dev;
 914        u32 hash_ms, hash_tid = 0;
 915        struct pdp_ctx *pctx;
 916        bool found = false;
 917        __be32 ms_addr;
 918
 919        ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
 920        hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
 921
 922        hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
 923                if (pctx->ms_addr_ip4.s_addr == ms_addr) {
 924                        found = true;
 925                        break;
 926                }
 927        }
 928
 929        if (found) {
 930                if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
 931                        return -EEXIST;
 932                if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
 933                        return -EOPNOTSUPP;
 934
 935                ipv4_pdp_fill(pctx, info);
 936
 937                if (pctx->gtp_version == GTP_V0)
 938                        netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
 939                                   pctx->u.v0.tid, pctx);
 940                else if (pctx->gtp_version == GTP_V1)
 941                        netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
 942                                   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
 943
 944                return 0;
 945
 946        }
 947
 948        pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
 949        if (pctx == NULL)
 950                return -ENOMEM;
 951
 952        sock_hold(sk);
 953        pctx->sk = sk;
 954        pctx->dev = gtp->dev;
 955        ipv4_pdp_fill(pctx, info);
 956        atomic_set(&pctx->tx_seq, 0);
 957
 958        switch (pctx->gtp_version) {
 959        case GTP_V0:
 960                /* TS 09.60: "The flow label identifies unambiguously a GTP
 961                 * flow.". We use the tid for this instead, I cannot find a
 962                 * situation in which this doesn't unambiguosly identify the
 963                 * PDP context.
 964                 */
 965                hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
 966                break;
 967        case GTP_V1:
 968                hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
 969                break;
 970        }
 971
 972        hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
 973        hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
 974
 975        switch (pctx->gtp_version) {
 976        case GTP_V0:
 977                netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
 978                           pctx->u.v0.tid, &pctx->peer_addr_ip4,
 979                           &pctx->ms_addr_ip4, pctx);
 980                break;
 981        case GTP_V1:
 982                netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
 983                           pctx->u.v1.i_tei, pctx->u.v1.o_tei,
 984                           &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
 985                break;
 986        }
 987
 988        return 0;
 989}
 990
 991static void pdp_context_free(struct rcu_head *head)
 992{
 993        struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
 994
 995        sock_put(pctx->sk);
 996        kfree(pctx);
 997}
 998
 999static void pdp_context_delete(struct pdp_ctx *pctx)
1000{
1001        hlist_del_rcu(&pctx->hlist_tid);
1002        hlist_del_rcu(&pctx->hlist_addr);
1003        call_rcu(&pctx->rcu_head, pdp_context_free);
1004}
1005
1006static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1007{
1008        unsigned int version;
1009        struct gtp_dev *gtp;
1010        struct sock *sk;
1011        int err;
1012
1013        if (!info->attrs[GTPA_VERSION] ||
1014            !info->attrs[GTPA_LINK] ||
1015            !info->attrs[GTPA_PEER_ADDRESS] ||
1016            !info->attrs[GTPA_MS_ADDRESS])
1017                return -EINVAL;
1018
1019        version = nla_get_u32(info->attrs[GTPA_VERSION]);
1020
1021        switch (version) {
1022        case GTP_V0:
1023                if (!info->attrs[GTPA_TID] ||
1024                    !info->attrs[GTPA_FLOW])
1025                        return -EINVAL;
1026                break;
1027        case GTP_V1:
1028                if (!info->attrs[GTPA_I_TEI] ||
1029                    !info->attrs[GTPA_O_TEI])
1030                        return -EINVAL;
1031                break;
1032
1033        default:
1034                return -EINVAL;
1035        }
1036
1037        rcu_read_lock();
1038
1039        gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1040        if (!gtp) {
1041                err = -ENODEV;
1042                goto out_unlock;
1043        }
1044
1045        if (version == GTP_V0)
1046                sk = gtp->sk0;
1047        else if (version == GTP_V1)
1048                sk = gtp->sk1u;
1049        else
1050                sk = NULL;
1051
1052        if (!sk) {
1053                err = -ENODEV;
1054                goto out_unlock;
1055        }
1056
1057        err = ipv4_pdp_add(gtp, sk, info);
1058
1059out_unlock:
1060        rcu_read_unlock();
1061        return err;
1062}
1063
1064static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1065                                            struct nlattr *nla[])
1066{
1067        struct gtp_dev *gtp;
1068
1069        gtp = gtp_find_dev(net, nla);
1070        if (!gtp)
1071                return ERR_PTR(-ENODEV);
1072
1073        if (nla[GTPA_MS_ADDRESS]) {
1074                __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1075
1076                return ipv4_pdp_find(gtp, ip);
1077        } else if (nla[GTPA_VERSION]) {
1078                u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1079
1080                if (gtp_version == GTP_V0 && nla[GTPA_TID])
1081                        return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1082                else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1083                        return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1084        }
1085
1086        return ERR_PTR(-EINVAL);
1087}
1088
1089static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1090{
1091        struct pdp_ctx *pctx;
1092
1093        if (nla[GTPA_LINK])
1094                pctx = gtp_find_pdp_by_link(net, nla);
1095        else
1096                pctx = ERR_PTR(-EINVAL);
1097
1098        if (!pctx)
1099                pctx = ERR_PTR(-ENOENT);
1100
1101        return pctx;
1102}
1103
1104static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1105{
1106        struct pdp_ctx *pctx;
1107        int err = 0;
1108
1109        if (!info->attrs[GTPA_VERSION])
1110                return -EINVAL;
1111
1112        rcu_read_lock();
1113
1114        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1115        if (IS_ERR(pctx)) {
1116                err = PTR_ERR(pctx);
1117                goto out_unlock;
1118        }
1119
1120        if (pctx->gtp_version == GTP_V0)
1121                netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1122                           pctx->u.v0.tid, pctx);
1123        else if (pctx->gtp_version == GTP_V1)
1124                netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1125                           pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1126
1127        pdp_context_delete(pctx);
1128
1129out_unlock:
1130        rcu_read_unlock();
1131        return err;
1132}
1133
1134static struct genl_family gtp_genl_family;
1135
1136static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1137                              u32 type, struct pdp_ctx *pctx)
1138{
1139        void *genlh;
1140
1141        genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
1142                            type);
1143        if (genlh == NULL)
1144                goto nlmsg_failure;
1145
1146        if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1147            nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1148            nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1149                goto nla_put_failure;
1150
1151        switch (pctx->gtp_version) {
1152        case GTP_V0:
1153                if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1154                    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1155                        goto nla_put_failure;
1156                break;
1157        case GTP_V1:
1158                if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1159                    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1160                        goto nla_put_failure;
1161                break;
1162        }
1163        genlmsg_end(skb, genlh);
1164        return 0;
1165
1166nlmsg_failure:
1167nla_put_failure:
1168        genlmsg_cancel(skb, genlh);
1169        return -EMSGSIZE;
1170}
1171
1172static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1173{
1174        struct pdp_ctx *pctx = NULL;
1175        struct sk_buff *skb2;
1176        int err;
1177
1178        if (!info->attrs[GTPA_VERSION])
1179                return -EINVAL;
1180
1181        rcu_read_lock();
1182
1183        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1184        if (IS_ERR(pctx)) {
1185                err = PTR_ERR(pctx);
1186                goto err_unlock;
1187        }
1188
1189        skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1190        if (skb2 == NULL) {
1191                err = -ENOMEM;
1192                goto err_unlock;
1193        }
1194
1195        err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1196                                 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1197        if (err < 0)
1198                goto err_unlock_free;
1199
1200        rcu_read_unlock();
1201        return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1202
1203err_unlock_free:
1204        kfree_skb(skb2);
1205err_unlock:
1206        rcu_read_unlock();
1207        return err;
1208}
1209
1210static int gtp_genl_dump_pdp(struct sk_buff *skb,
1211                                struct netlink_callback *cb)
1212{
1213        struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1214        struct net *net = sock_net(skb->sk);
1215        struct gtp_net *gn = net_generic(net, gtp_net_id);
1216        unsigned long tid = cb->args[1];
1217        int i, k = cb->args[0], ret;
1218        struct pdp_ctx *pctx;
1219
1220        if (cb->args[4])
1221                return 0;
1222
1223        list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1224                if (last_gtp && last_gtp != gtp)
1225                        continue;
1226                else
1227                        last_gtp = NULL;
1228
1229                for (i = k; i < gtp->hash_size; i++) {
1230                        hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
1231                                if (tid && tid != pctx->u.tid)
1232                                        continue;
1233                                else
1234                                        tid = 0;
1235
1236                                ret = gtp_genl_fill_info(skb,
1237                                                         NETLINK_CB(cb->skb).portid,
1238                                                         cb->nlh->nlmsg_seq,
1239                                                         cb->nlh->nlmsg_type, pctx);
1240                                if (ret < 0) {
1241                                        cb->args[0] = i;
1242                                        cb->args[1] = pctx->u.tid;
1243                                        cb->args[2] = (unsigned long)gtp;
1244                                        goto out;
1245                                }
1246                        }
1247                }
1248        }
1249        cb->args[4] = 1;
1250out:
1251        return skb->len;
1252}
1253
1254static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1255        [GTPA_LINK]             = { .type = NLA_U32, },
1256        [GTPA_VERSION]          = { .type = NLA_U32, },
1257        [GTPA_TID]              = { .type = NLA_U64, },
1258        [GTPA_PEER_ADDRESS]     = { .type = NLA_U32, },
1259        [GTPA_MS_ADDRESS]       = { .type = NLA_U32, },
1260        [GTPA_FLOW]             = { .type = NLA_U16, },
1261        [GTPA_NET_NS_FD]        = { .type = NLA_U32, },
1262        [GTPA_I_TEI]            = { .type = NLA_U32, },
1263        [GTPA_O_TEI]            = { .type = NLA_U32, },
1264};
1265
1266static const struct genl_ops gtp_genl_ops[] = {
1267        {
1268                .cmd = GTP_CMD_NEWPDP,
1269                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1270                .doit = gtp_genl_new_pdp,
1271                .flags = GENL_ADMIN_PERM,
1272        },
1273        {
1274                .cmd = GTP_CMD_DELPDP,
1275                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1276                .doit = gtp_genl_del_pdp,
1277                .flags = GENL_ADMIN_PERM,
1278        },
1279        {
1280                .cmd = GTP_CMD_GETPDP,
1281                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1282                .doit = gtp_genl_get_pdp,
1283                .dumpit = gtp_genl_dump_pdp,
1284                .flags = GENL_ADMIN_PERM,
1285        },
1286};
1287
1288static struct genl_family gtp_genl_family __ro_after_init = {
1289        .name           = "gtp",
1290        .version        = 0,
1291        .hdrsize        = 0,
1292        .maxattr        = GTPA_MAX,
1293        .policy = gtp_genl_policy,
1294        .netnsok        = true,
1295        .module         = THIS_MODULE,
1296        .ops            = gtp_genl_ops,
1297        .n_ops          = ARRAY_SIZE(gtp_genl_ops),
1298};
1299
1300static int __net_init gtp_net_init(struct net *net)
1301{
1302        struct gtp_net *gn = net_generic(net, gtp_net_id);
1303
1304        INIT_LIST_HEAD(&gn->gtp_dev_list);
1305        return 0;
1306}
1307
1308static void __net_exit gtp_net_exit(struct net *net)
1309{
1310        struct gtp_net *gn = net_generic(net, gtp_net_id);
1311        struct gtp_dev *gtp;
1312        LIST_HEAD(list);
1313
1314        rtnl_lock();
1315        list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1316                gtp_dellink(gtp->dev, &list);
1317
1318        unregister_netdevice_many(&list);
1319        rtnl_unlock();
1320}
1321
1322static struct pernet_operations gtp_net_ops = {
1323        .init   = gtp_net_init,
1324        .exit   = gtp_net_exit,
1325        .id     = &gtp_net_id,
1326        .size   = sizeof(struct gtp_net),
1327};
1328
1329static int __init gtp_init(void)
1330{
1331        int err;
1332
1333        get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1334
1335        err = rtnl_link_register(&gtp_link_ops);
1336        if (err < 0)
1337                goto error_out;
1338
1339        err = genl_register_family(&gtp_genl_family);
1340        if (err < 0)
1341                goto unreg_rtnl_link;
1342
1343        err = register_pernet_subsys(&gtp_net_ops);
1344        if (err < 0)
1345                goto unreg_genl_family;
1346
1347        pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1348                sizeof(struct pdp_ctx));
1349        return 0;
1350
1351unreg_genl_family:
1352        genl_unregister_family(&gtp_genl_family);
1353unreg_rtnl_link:
1354        rtnl_link_unregister(&gtp_link_ops);
1355error_out:
1356        pr_err("error loading GTP module loaded\n");
1357        return err;
1358}
1359late_initcall(gtp_init);
1360
1361static void __exit gtp_fini(void)
1362{
1363        unregister_pernet_subsys(&gtp_net_ops);
1364        genl_unregister_family(&gtp_genl_family);
1365        rtnl_link_unregister(&gtp_link_ops);
1366
1367        pr_info("GTP module unloaded\n");
1368}
1369module_exit(gtp_fini);
1370
1371MODULE_LICENSE("GPL");
1372MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1373MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1374MODULE_ALIAS_RTNL_LINK("gtp");
1375MODULE_ALIAS_GENL_FAMILY("gtp");
1376