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                struct {
  42                        u64     tid;
  43                        u16     flow;
  44                } v0;
  45                struct {
  46                        u32     i_tei;
  47                        u32     o_tei;
  48                } v1;
  49        } u;
  50        u8                      gtp_version;
  51        u16                     af;
  52
  53        struct in_addr          ms_addr_ip4;
  54        struct in_addr          peer_addr_ip4;
  55
  56        struct sock             *sk;
  57        struct net_device       *dev;
  58
  59        atomic_t                tx_seq;
  60        struct rcu_head         rcu_head;
  61};
  62
  63/* One instance of the GTP device. */
  64struct gtp_dev {
  65        struct list_head        list;
  66
  67        struct sock             *sk0;
  68        struct sock             *sk1u;
  69
  70        struct net_device       *dev;
  71
  72        unsigned int            role;
  73        unsigned int            hash_size;
  74        struct hlist_head       *tid_hash;
  75        struct hlist_head       *addr_hash;
  76};
  77
  78static unsigned int gtp_net_id __read_mostly;
  79
  80struct gtp_net {
  81        struct list_head gtp_dev_list;
  82};
  83
  84static u32 gtp_h_initval;
  85
  86static void pdp_context_delete(struct pdp_ctx *pctx);
  87
  88static inline u32 gtp0_hashfn(u64 tid)
  89{
  90        u32 *tid32 = (u32 *) &tid;
  91        return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
  92}
  93
  94static inline u32 gtp1u_hashfn(u32 tid)
  95{
  96        return jhash_1word(tid, gtp_h_initval);
  97}
  98
  99static inline u32 ipv4_hashfn(__be32 ip)
 100{
 101        return jhash_1word((__force u32)ip, gtp_h_initval);
 102}
 103
 104/* Resolve a PDP context structure based on the 64bit TID. */
 105static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
 106{
 107        struct hlist_head *head;
 108        struct pdp_ctx *pdp;
 109
 110        head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
 111
 112        hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
 113                if (pdp->gtp_version == GTP_V0 &&
 114                    pdp->u.v0.tid == tid)
 115                        return pdp;
 116        }
 117        return NULL;
 118}
 119
 120/* Resolve a PDP context structure based on the 32bit TEI. */
 121static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
 122{
 123        struct hlist_head *head;
 124        struct pdp_ctx *pdp;
 125
 126        head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
 127
 128        hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
 129                if (pdp->gtp_version == GTP_V1 &&
 130                    pdp->u.v1.i_tei == tid)
 131                        return pdp;
 132        }
 133        return NULL;
 134}
 135
 136/* Resolve a PDP context based on IPv4 address of MS. */
 137static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
 138{
 139        struct hlist_head *head;
 140        struct pdp_ctx *pdp;
 141
 142        head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
 143
 144        hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
 145                if (pdp->af == AF_INET &&
 146                    pdp->ms_addr_ip4.s_addr == ms_addr)
 147                        return pdp;
 148        }
 149
 150        return NULL;
 151}
 152
 153static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
 154                                  unsigned int hdrlen, unsigned int role)
 155{
 156        struct iphdr *iph;
 157
 158        if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
 159                return false;
 160
 161        iph = (struct iphdr *)(skb->data + hdrlen);
 162
 163        if (role == GTP_ROLE_SGSN)
 164                return iph->daddr == pctx->ms_addr_ip4.s_addr;
 165        else
 166                return iph->saddr == pctx->ms_addr_ip4.s_addr;
 167}
 168
 169/* Check if the inner IP address in this packet is assigned to any
 170 * existing mobile subscriber.
 171 */
 172static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
 173                             unsigned int hdrlen, unsigned int role)
 174{
 175        switch (ntohs(skb->protocol)) {
 176        case ETH_P_IP:
 177                return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
 178        }
 179        return false;
 180}
 181
 182static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
 183                        unsigned int hdrlen, unsigned int role)
 184{
 185        if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
 186                netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
 187                return 1;
 188        }
 189
 190        /* Get rid of the GTP + UDP headers. */
 191        if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
 192                         !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
 193                pctx->dev->stats.rx_length_errors++;
 194                goto err;
 195        }
 196
 197        netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
 198
 199        /* Now that the UDP and the GTP header have been removed, set up the
 200         * new network header. This is required by the upper layer to
 201         * calculate the transport header.
 202         */
 203        skb_reset_network_header(skb);
 204        skb_reset_mac_header(skb);
 205
 206        skb->dev = pctx->dev;
 207
 208        dev_sw_netstats_rx_add(pctx->dev, skb->len);
 209
 210        netif_rx(skb);
 211        return 0;
 212
 213err:
 214        pctx->dev->stats.rx_dropped++;
 215        return -1;
 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        lock_sock(sk);
 293        gtp = sk->sk_user_data;
 294        if (gtp) {
 295                if (gtp->sk0 == sk)
 296                        gtp->sk0 = NULL;
 297                else
 298                        gtp->sk1u = NULL;
 299                udp_sk(sk)->encap_type = 0;
 300                rcu_assign_sk_user_data(sk, NULL);
 301                sock_put(sk);
 302        }
 303        release_sock(sk);
 304}
 305
 306static void gtp_encap_destroy(struct sock *sk)
 307{
 308        rtnl_lock();
 309        __gtp_encap_destroy(sk);
 310        rtnl_unlock();
 311}
 312
 313static void gtp_encap_disable_sock(struct sock *sk)
 314{
 315        if (!sk)
 316                return;
 317
 318        __gtp_encap_destroy(sk);
 319}
 320
 321static void gtp_encap_disable(struct gtp_dev *gtp)
 322{
 323        gtp_encap_disable_sock(gtp->sk0);
 324        gtp_encap_disable_sock(gtp->sk1u);
 325}
 326
 327/* UDP encapsulation receive handler. See net/ipv4/udp.c.
 328 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
 329 */
 330static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
 331{
 332        struct gtp_dev *gtp;
 333        int ret = 0;
 334
 335        gtp = rcu_dereference_sk_user_data(sk);
 336        if (!gtp)
 337                return 1;
 338
 339        netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
 340
 341        switch (udp_sk(sk)->encap_type) {
 342        case UDP_ENCAP_GTP0:
 343                netdev_dbg(gtp->dev, "received GTP0 packet\n");
 344                ret = gtp0_udp_encap_recv(gtp, skb);
 345                break;
 346        case UDP_ENCAP_GTP1U:
 347                netdev_dbg(gtp->dev, "received GTP1U packet\n");
 348                ret = gtp1u_udp_encap_recv(gtp, skb);
 349                break;
 350        default:
 351                ret = -1; /* Shouldn't happen. */
 352        }
 353
 354        switch (ret) {
 355        case 1:
 356                netdev_dbg(gtp->dev, "pass up to the process\n");
 357                break;
 358        case 0:
 359                break;
 360        case -1:
 361                netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
 362                kfree_skb(skb);
 363                ret = 0;
 364                break;
 365        }
 366
 367        return ret;
 368}
 369
 370static int gtp_dev_init(struct net_device *dev)
 371{
 372        struct gtp_dev *gtp = netdev_priv(dev);
 373
 374        gtp->dev = dev;
 375
 376        dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 377        if (!dev->tstats)
 378                return -ENOMEM;
 379
 380        return 0;
 381}
 382
 383static void gtp_dev_uninit(struct net_device *dev)
 384{
 385        struct gtp_dev *gtp = netdev_priv(dev);
 386
 387        gtp_encap_disable(gtp);
 388        free_percpu(dev->tstats);
 389}
 390
 391static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
 392                                           const struct sock *sk,
 393                                           __be32 daddr)
 394{
 395        memset(fl4, 0, sizeof(*fl4));
 396        fl4->flowi4_oif         = sk->sk_bound_dev_if;
 397        fl4->daddr              = daddr;
 398        fl4->saddr              = inet_sk(sk)->inet_saddr;
 399        fl4->flowi4_tos         = RT_CONN_FLAGS(sk);
 400        fl4->flowi4_proto       = sk->sk_protocol;
 401
 402        return ip_route_output_key(sock_net(sk), fl4);
 403}
 404
 405static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 406{
 407        int payload_len = skb->len;
 408        struct gtp0_header *gtp0;
 409
 410        gtp0 = skb_push(skb, sizeof(*gtp0));
 411
 412        gtp0->flags     = 0x1e; /* v0, GTP-non-prime. */
 413        gtp0->type      = GTP_TPDU;
 414        gtp0->length    = htons(payload_len);
 415        gtp0->seq       = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
 416        gtp0->flow      = htons(pctx->u.v0.flow);
 417        gtp0->number    = 0xff;
 418        gtp0->spare[0]  = gtp0->spare[1] = gtp0->spare[2] = 0xff;
 419        gtp0->tid       = cpu_to_be64(pctx->u.v0.tid);
 420}
 421
 422static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
 423{
 424        int payload_len = skb->len;
 425        struct gtp1_header *gtp1;
 426
 427        gtp1 = skb_push(skb, sizeof(*gtp1));
 428
 429        /* Bits    8  7  6  5  4  3  2  1
 430         *        +--+--+--+--+--+--+--+--+
 431         *        |version |PT| 0| E| S|PN|
 432         *        +--+--+--+--+--+--+--+--+
 433         *          0  0  1  1  1  0  0  0
 434         */
 435        gtp1->flags     = 0x30; /* v1, GTP-non-prime. */
 436        gtp1->type      = GTP_TPDU;
 437        gtp1->length    = htons(payload_len);
 438        gtp1->tid       = htonl(pctx->u.v1.o_tei);
 439
 440        /* TODO: Support for extension header, sequence number and N-PDU.
 441         *       Update the length field if any of them is available.
 442         */
 443}
 444
 445struct gtp_pktinfo {
 446        struct sock             *sk;
 447        struct iphdr            *iph;
 448        struct flowi4           fl4;
 449        struct rtable           *rt;
 450        struct pdp_ctx          *pctx;
 451        struct net_device       *dev;
 452        __be16                  gtph_port;
 453};
 454
 455static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
 456{
 457        switch (pktinfo->pctx->gtp_version) {
 458        case GTP_V0:
 459                pktinfo->gtph_port = htons(GTP0_PORT);
 460                gtp0_push_header(skb, pktinfo->pctx);
 461                break;
 462        case GTP_V1:
 463                pktinfo->gtph_port = htons(GTP1U_PORT);
 464                gtp1_push_header(skb, pktinfo->pctx);
 465                break;
 466        }
 467}
 468
 469static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
 470                                        struct sock *sk, struct iphdr *iph,
 471                                        struct pdp_ctx *pctx, struct rtable *rt,
 472                                        struct flowi4 *fl4,
 473                                        struct net_device *dev)
 474{
 475        pktinfo->sk     = sk;
 476        pktinfo->iph    = iph;
 477        pktinfo->pctx   = pctx;
 478        pktinfo->rt     = rt;
 479        pktinfo->fl4    = *fl4;
 480        pktinfo->dev    = dev;
 481}
 482
 483static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
 484                             struct gtp_pktinfo *pktinfo)
 485{
 486        struct gtp_dev *gtp = netdev_priv(dev);
 487        struct pdp_ctx *pctx;
 488        struct rtable *rt;
 489        struct flowi4 fl4;
 490        struct iphdr *iph;
 491        __be16 df;
 492        int mtu;
 493
 494        /* Read the IP destination address and resolve the PDP context.
 495         * Prepend PDP header with TEI/TID from PDP ctx.
 496         */
 497        iph = ip_hdr(skb);
 498        if (gtp->role == GTP_ROLE_SGSN)
 499                pctx = ipv4_pdp_find(gtp, iph->saddr);
 500        else
 501                pctx = ipv4_pdp_find(gtp, iph->daddr);
 502
 503        if (!pctx) {
 504                netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
 505                           &iph->daddr);
 506                return -ENOENT;
 507        }
 508        netdev_dbg(dev, "found PDP context %p\n", pctx);
 509
 510        rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
 511        if (IS_ERR(rt)) {
 512                netdev_dbg(dev, "no route to SSGN %pI4\n",
 513                           &pctx->peer_addr_ip4.s_addr);
 514                dev->stats.tx_carrier_errors++;
 515                goto err;
 516        }
 517
 518        if (rt->dst.dev == dev) {
 519                netdev_dbg(dev, "circular route to SSGN %pI4\n",
 520                           &pctx->peer_addr_ip4.s_addr);
 521                dev->stats.collisions++;
 522                goto err_rt;
 523        }
 524
 525        /* This is similar to tnl_update_pmtu(). */
 526        df = iph->frag_off;
 527        if (df) {
 528                mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
 529                        sizeof(struct iphdr) - sizeof(struct udphdr);
 530                switch (pctx->gtp_version) {
 531                case GTP_V0:
 532                        mtu -= sizeof(struct gtp0_header);
 533                        break;
 534                case GTP_V1:
 535                        mtu -= sizeof(struct gtp1_header);
 536                        break;
 537                }
 538        } else {
 539                mtu = dst_mtu(&rt->dst);
 540        }
 541
 542        rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
 543
 544        if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
 545            mtu < ntohs(iph->tot_len)) {
 546                netdev_dbg(dev, "packet too big, fragmentation needed\n");
 547                icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 548                              htonl(mtu));
 549                goto err_rt;
 550        }
 551
 552        gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
 553        gtp_push_header(skb, pktinfo);
 554
 555        return 0;
 556err_rt:
 557        ip_rt_put(rt);
 558err:
 559        return -EBADMSG;
 560}
 561
 562static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 563{
 564        unsigned int proto = ntohs(skb->protocol);
 565        struct gtp_pktinfo pktinfo;
 566        int err;
 567
 568        /* Ensure there is sufficient headroom. */
 569        if (skb_cow_head(skb, dev->needed_headroom))
 570                goto tx_err;
 571
 572        skb_reset_inner_headers(skb);
 573
 574        /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
 575        rcu_read_lock();
 576        switch (proto) {
 577        case ETH_P_IP:
 578                err = gtp_build_skb_ip4(skb, dev, &pktinfo);
 579                break;
 580        default:
 581                err = -EOPNOTSUPP;
 582                break;
 583        }
 584        rcu_read_unlock();
 585
 586        if (err < 0)
 587                goto tx_err;
 588
 589        switch (proto) {
 590        case ETH_P_IP:
 591                netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
 592                           &pktinfo.iph->saddr, &pktinfo.iph->daddr);
 593                udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
 594                                    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
 595                                    pktinfo.iph->tos,
 596                                    ip4_dst_hoplimit(&pktinfo.rt->dst),
 597                                    0,
 598                                    pktinfo.gtph_port, pktinfo.gtph_port,
 599                                    !net_eq(sock_net(pktinfo.pctx->sk),
 600                                            dev_net(dev)),
 601                                    false);
 602                break;
 603        }
 604
 605        return NETDEV_TX_OK;
 606tx_err:
 607        dev->stats.tx_errors++;
 608        dev_kfree_skb(skb);
 609        return NETDEV_TX_OK;
 610}
 611
 612static const struct net_device_ops gtp_netdev_ops = {
 613        .ndo_init               = gtp_dev_init,
 614        .ndo_uninit             = gtp_dev_uninit,
 615        .ndo_start_xmit         = gtp_dev_xmit,
 616        .ndo_get_stats64        = dev_get_tstats64,
 617};
 618
 619static const struct device_type gtp_type = {
 620        .name = "gtp",
 621};
 622
 623static void gtp_link_setup(struct net_device *dev)
 624{
 625        unsigned int max_gtp_header_len = sizeof(struct iphdr) +
 626                                          sizeof(struct udphdr) +
 627                                          sizeof(struct gtp0_header);
 628
 629        dev->netdev_ops         = &gtp_netdev_ops;
 630        dev->needs_free_netdev  = true;
 631        SET_NETDEV_DEVTYPE(dev, &gtp_type);
 632
 633        dev->hard_header_len = 0;
 634        dev->addr_len = 0;
 635        dev->mtu = ETH_DATA_LEN - max_gtp_header_len;
 636
 637        /* Zero header length. */
 638        dev->type = ARPHRD_NONE;
 639        dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 640
 641        dev->priv_flags |= IFF_NO_QUEUE;
 642        dev->features   |= NETIF_F_LLTX;
 643        netif_keep_dst(dev);
 644
 645        dev->needed_headroom    = LL_MAX_HEADER + max_gtp_header_len;
 646}
 647
 648static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
 649static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
 650
 651static void gtp_destructor(struct net_device *dev)
 652{
 653        struct gtp_dev *gtp = netdev_priv(dev);
 654
 655        kfree(gtp->addr_hash);
 656        kfree(gtp->tid_hash);
 657}
 658
 659static int gtp_newlink(struct net *src_net, struct net_device *dev,
 660                       struct nlattr *tb[], struct nlattr *data[],
 661                       struct netlink_ext_ack *extack)
 662{
 663        struct gtp_dev *gtp;
 664        struct gtp_net *gn;
 665        int hashsize, err;
 666
 667        if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
 668                return -EINVAL;
 669
 670        gtp = netdev_priv(dev);
 671
 672        if (!data[IFLA_GTP_PDP_HASHSIZE]) {
 673                hashsize = 1024;
 674        } else {
 675                hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
 676                if (!hashsize)
 677                        hashsize = 1024;
 678        }
 679
 680        err = gtp_hashtable_new(gtp, hashsize);
 681        if (err < 0)
 682                return err;
 683
 684        err = gtp_encap_enable(gtp, data);
 685        if (err < 0)
 686                goto out_hashtable;
 687
 688        err = register_netdevice(dev);
 689        if (err < 0) {
 690                netdev_dbg(dev, "failed to register new netdev %d\n", err);
 691                goto out_encap;
 692        }
 693
 694        gn = net_generic(dev_net(dev), gtp_net_id);
 695        list_add_rcu(&gtp->list, &gn->gtp_dev_list);
 696        dev->priv_destructor = gtp_destructor;
 697
 698        netdev_dbg(dev, "registered new GTP interface\n");
 699
 700        return 0;
 701
 702out_encap:
 703        gtp_encap_disable(gtp);
 704out_hashtable:
 705        kfree(gtp->addr_hash);
 706        kfree(gtp->tid_hash);
 707        return err;
 708}
 709
 710static void gtp_dellink(struct net_device *dev, struct list_head *head)
 711{
 712        struct gtp_dev *gtp = netdev_priv(dev);
 713        struct pdp_ctx *pctx;
 714        int i;
 715
 716        for (i = 0; i < gtp->hash_size; i++)
 717                hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
 718                        pdp_context_delete(pctx);
 719
 720        list_del_rcu(&gtp->list);
 721        unregister_netdevice_queue(dev, head);
 722}
 723
 724static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
 725        [IFLA_GTP_FD0]                  = { .type = NLA_U32 },
 726        [IFLA_GTP_FD1]                  = { .type = NLA_U32 },
 727        [IFLA_GTP_PDP_HASHSIZE]         = { .type = NLA_U32 },
 728        [IFLA_GTP_ROLE]                 = { .type = NLA_U32 },
 729};
 730
 731static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
 732                        struct netlink_ext_ack *extack)
 733{
 734        if (!data)
 735                return -EINVAL;
 736
 737        return 0;
 738}
 739
 740static size_t gtp_get_size(const struct net_device *dev)
 741{
 742        return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
 743                nla_total_size(sizeof(__u32)); /* IFLA_GTP_ROLE */
 744}
 745
 746static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
 747{
 748        struct gtp_dev *gtp = netdev_priv(dev);
 749
 750        if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
 751                goto nla_put_failure;
 752        if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
 753                goto nla_put_failure;
 754
 755        return 0;
 756
 757nla_put_failure:
 758        return -EMSGSIZE;
 759}
 760
 761static struct rtnl_link_ops gtp_link_ops __read_mostly = {
 762        .kind           = "gtp",
 763        .maxtype        = IFLA_GTP_MAX,
 764        .policy         = gtp_policy,
 765        .priv_size      = sizeof(struct gtp_dev),
 766        .setup          = gtp_link_setup,
 767        .validate       = gtp_validate,
 768        .newlink        = gtp_newlink,
 769        .dellink        = gtp_dellink,
 770        .get_size       = gtp_get_size,
 771        .fill_info      = gtp_fill_info,
 772};
 773
 774static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
 775{
 776        int i;
 777
 778        gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
 779                                       GFP_KERNEL | __GFP_NOWARN);
 780        if (gtp->addr_hash == NULL)
 781                return -ENOMEM;
 782
 783        gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
 784                                      GFP_KERNEL | __GFP_NOWARN);
 785        if (gtp->tid_hash == NULL)
 786                goto err1;
 787
 788        gtp->hash_size = hsize;
 789
 790        for (i = 0; i < hsize; i++) {
 791                INIT_HLIST_HEAD(&gtp->addr_hash[i]);
 792                INIT_HLIST_HEAD(&gtp->tid_hash[i]);
 793        }
 794        return 0;
 795err1:
 796        kfree(gtp->addr_hash);
 797        return -ENOMEM;
 798}
 799
 800static struct sock *gtp_encap_enable_socket(int fd, int type,
 801                                            struct gtp_dev *gtp)
 802{
 803        struct udp_tunnel_sock_cfg tuncfg = {NULL};
 804        struct socket *sock;
 805        struct sock *sk;
 806        int err;
 807
 808        pr_debug("enable gtp on %d, %d\n", fd, type);
 809
 810        sock = sockfd_lookup(fd, &err);
 811        if (!sock) {
 812                pr_debug("gtp socket fd=%d not found\n", fd);
 813                return NULL;
 814        }
 815
 816        sk = sock->sk;
 817        if (sk->sk_protocol != IPPROTO_UDP ||
 818            sk->sk_type != SOCK_DGRAM ||
 819            (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
 820                pr_debug("socket fd=%d not UDP\n", fd);
 821                sk = ERR_PTR(-EINVAL);
 822                goto out_sock;
 823        }
 824
 825        lock_sock(sk);
 826        if (sk->sk_user_data) {
 827                sk = ERR_PTR(-EBUSY);
 828                goto out_rel_sock;
 829        }
 830
 831        sock_hold(sk);
 832
 833        tuncfg.sk_user_data = gtp;
 834        tuncfg.encap_type = type;
 835        tuncfg.encap_rcv = gtp_encap_recv;
 836        tuncfg.encap_destroy = gtp_encap_destroy;
 837
 838        setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
 839
 840out_rel_sock:
 841        release_sock(sock->sk);
 842out_sock:
 843        sockfd_put(sock);
 844        return sk;
 845}
 846
 847static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
 848{
 849        struct sock *sk1u = NULL;
 850        struct sock *sk0 = NULL;
 851        unsigned int role = GTP_ROLE_GGSN;
 852
 853        if (data[IFLA_GTP_FD0]) {
 854                u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
 855
 856                sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
 857                if (IS_ERR(sk0))
 858                        return PTR_ERR(sk0);
 859        }
 860
 861        if (data[IFLA_GTP_FD1]) {
 862                u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
 863
 864                sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
 865                if (IS_ERR(sk1u)) {
 866                        gtp_encap_disable_sock(sk0);
 867                        return PTR_ERR(sk1u);
 868                }
 869        }
 870
 871        if (data[IFLA_GTP_ROLE]) {
 872                role = nla_get_u32(data[IFLA_GTP_ROLE]);
 873                if (role > GTP_ROLE_SGSN) {
 874                        gtp_encap_disable_sock(sk0);
 875                        gtp_encap_disable_sock(sk1u);
 876                        return -EINVAL;
 877                }
 878        }
 879
 880        gtp->sk0 = sk0;
 881        gtp->sk1u = sk1u;
 882        gtp->role = role;
 883
 884        return 0;
 885}
 886
 887static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
 888{
 889        struct gtp_dev *gtp = NULL;
 890        struct net_device *dev;
 891        struct net *net;
 892
 893        /* Examine the link attributes and figure out which network namespace
 894         * we are talking about.
 895         */
 896        if (nla[GTPA_NET_NS_FD])
 897                net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
 898        else
 899                net = get_net(src_net);
 900
 901        if (IS_ERR(net))
 902                return NULL;
 903
 904        /* Check if there's an existing gtpX device to configure */
 905        dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
 906        if (dev && dev->netdev_ops == &gtp_netdev_ops)
 907                gtp = netdev_priv(dev);
 908
 909        put_net(net);
 910        return gtp;
 911}
 912
 913static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
 914{
 915        pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
 916        pctx->af = AF_INET;
 917        pctx->peer_addr_ip4.s_addr =
 918                nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
 919        pctx->ms_addr_ip4.s_addr =
 920                nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
 921
 922        switch (pctx->gtp_version) {
 923        case GTP_V0:
 924                /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
 925                 * label needs to be the same for uplink and downlink packets,
 926                 * so let's annotate this.
 927                 */
 928                pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
 929                pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
 930                break;
 931        case GTP_V1:
 932                pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
 933                pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
 934                break;
 935        default:
 936                break;
 937        }
 938}
 939
 940static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
 941                                   struct genl_info *info)
 942{
 943        struct pdp_ctx *pctx, *pctx_tid = NULL;
 944        struct net_device *dev = gtp->dev;
 945        u32 hash_ms, hash_tid = 0;
 946        unsigned int version;
 947        bool found = false;
 948        __be32 ms_addr;
 949
 950        ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
 951        hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
 952        version = nla_get_u32(info->attrs[GTPA_VERSION]);
 953
 954        pctx = ipv4_pdp_find(gtp, ms_addr);
 955        if (pctx)
 956                found = true;
 957        if (version == GTP_V0)
 958                pctx_tid = gtp0_pdp_find(gtp,
 959                                         nla_get_u64(info->attrs[GTPA_TID]));
 960        else if (version == GTP_V1)
 961                pctx_tid = gtp1_pdp_find(gtp,
 962                                         nla_get_u32(info->attrs[GTPA_I_TEI]));
 963        if (pctx_tid)
 964                found = true;
 965
 966        if (found) {
 967                if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
 968                        return ERR_PTR(-EEXIST);
 969                if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
 970                        return ERR_PTR(-EOPNOTSUPP);
 971
 972                if (pctx && pctx_tid)
 973                        return ERR_PTR(-EEXIST);
 974                if (!pctx)
 975                        pctx = pctx_tid;
 976
 977                ipv4_pdp_fill(pctx, info);
 978
 979                if (pctx->gtp_version == GTP_V0)
 980                        netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
 981                                   pctx->u.v0.tid, pctx);
 982                else if (pctx->gtp_version == GTP_V1)
 983                        netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
 984                                   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
 985
 986                return pctx;
 987
 988        }
 989
 990        pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
 991        if (pctx == NULL)
 992                return ERR_PTR(-ENOMEM);
 993
 994        sock_hold(sk);
 995        pctx->sk = sk;
 996        pctx->dev = gtp->dev;
 997        ipv4_pdp_fill(pctx, info);
 998        atomic_set(&pctx->tx_seq, 0);
 999
1000        switch (pctx->gtp_version) {
1001        case GTP_V0:
1002                /* TS 09.60: "The flow label identifies unambiguously a GTP
1003                 * flow.". We use the tid for this instead, I cannot find a
1004                 * situation in which this doesn't unambiguosly identify the
1005                 * PDP context.
1006                 */
1007                hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1008                break;
1009        case GTP_V1:
1010                hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1011                break;
1012        }
1013
1014        hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
1015        hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
1016
1017        switch (pctx->gtp_version) {
1018        case GTP_V0:
1019                netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1020                           pctx->u.v0.tid, &pctx->peer_addr_ip4,
1021                           &pctx->ms_addr_ip4, pctx);
1022                break;
1023        case GTP_V1:
1024                netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1025                           pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1026                           &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1027                break;
1028        }
1029
1030        return pctx;
1031}
1032
1033static void pdp_context_free(struct rcu_head *head)
1034{
1035        struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1036
1037        sock_put(pctx->sk);
1038        kfree(pctx);
1039}
1040
1041static void pdp_context_delete(struct pdp_ctx *pctx)
1042{
1043        hlist_del_rcu(&pctx->hlist_tid);
1044        hlist_del_rcu(&pctx->hlist_addr);
1045        call_rcu(&pctx->rcu_head, pdp_context_free);
1046}
1047
1048static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1049
1050static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1051{
1052        unsigned int version;
1053        struct pdp_ctx *pctx;
1054        struct gtp_dev *gtp;
1055        struct sock *sk;
1056        int err;
1057
1058        if (!info->attrs[GTPA_VERSION] ||
1059            !info->attrs[GTPA_LINK] ||
1060            !info->attrs[GTPA_PEER_ADDRESS] ||
1061            !info->attrs[GTPA_MS_ADDRESS])
1062                return -EINVAL;
1063
1064        version = nla_get_u32(info->attrs[GTPA_VERSION]);
1065
1066        switch (version) {
1067        case GTP_V0:
1068                if (!info->attrs[GTPA_TID] ||
1069                    !info->attrs[GTPA_FLOW])
1070                        return -EINVAL;
1071                break;
1072        case GTP_V1:
1073                if (!info->attrs[GTPA_I_TEI] ||
1074                    !info->attrs[GTPA_O_TEI])
1075                        return -EINVAL;
1076                break;
1077
1078        default:
1079                return -EINVAL;
1080        }
1081
1082        rtnl_lock();
1083
1084        gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1085        if (!gtp) {
1086                err = -ENODEV;
1087                goto out_unlock;
1088        }
1089
1090        if (version == GTP_V0)
1091                sk = gtp->sk0;
1092        else if (version == GTP_V1)
1093                sk = gtp->sk1u;
1094        else
1095                sk = NULL;
1096
1097        if (!sk) {
1098                err = -ENODEV;
1099                goto out_unlock;
1100        }
1101
1102        pctx = gtp_pdp_add(gtp, sk, info);
1103        if (IS_ERR(pctx)) {
1104                err = PTR_ERR(pctx);
1105        } else {
1106                gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1107                err = 0;
1108        }
1109
1110out_unlock:
1111        rtnl_unlock();
1112        return err;
1113}
1114
1115static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1116                                            struct nlattr *nla[])
1117{
1118        struct gtp_dev *gtp;
1119
1120        gtp = gtp_find_dev(net, nla);
1121        if (!gtp)
1122                return ERR_PTR(-ENODEV);
1123
1124        if (nla[GTPA_MS_ADDRESS]) {
1125                __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1126
1127                return ipv4_pdp_find(gtp, ip);
1128        } else if (nla[GTPA_VERSION]) {
1129                u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1130
1131                if (gtp_version == GTP_V0 && nla[GTPA_TID])
1132                        return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1133                else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1134                        return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1135        }
1136
1137        return ERR_PTR(-EINVAL);
1138}
1139
1140static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1141{
1142        struct pdp_ctx *pctx;
1143
1144        if (nla[GTPA_LINK])
1145                pctx = gtp_find_pdp_by_link(net, nla);
1146        else
1147                pctx = ERR_PTR(-EINVAL);
1148
1149        if (!pctx)
1150                pctx = ERR_PTR(-ENOENT);
1151
1152        return pctx;
1153}
1154
1155static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1156{
1157        struct pdp_ctx *pctx;
1158        int err = 0;
1159
1160        if (!info->attrs[GTPA_VERSION])
1161                return -EINVAL;
1162
1163        rcu_read_lock();
1164
1165        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1166        if (IS_ERR(pctx)) {
1167                err = PTR_ERR(pctx);
1168                goto out_unlock;
1169        }
1170
1171        if (pctx->gtp_version == GTP_V0)
1172                netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1173                           pctx->u.v0.tid, pctx);
1174        else if (pctx->gtp_version == GTP_V1)
1175                netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1176                           pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1177
1178        gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1179        pdp_context_delete(pctx);
1180
1181out_unlock:
1182        rcu_read_unlock();
1183        return err;
1184}
1185
1186static struct genl_family gtp_genl_family;
1187
1188enum gtp_multicast_groups {
1189        GTP_GENL_MCGRP,
1190};
1191
1192static const struct genl_multicast_group gtp_genl_mcgrps[] = {
1193        [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
1194};
1195
1196static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1197                              int flags, u32 type, struct pdp_ctx *pctx)
1198{
1199        void *genlh;
1200
1201        genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
1202                            type);
1203        if (genlh == NULL)
1204                goto nlmsg_failure;
1205
1206        if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1207            nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1208            nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1209            nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1210                goto nla_put_failure;
1211
1212        switch (pctx->gtp_version) {
1213        case GTP_V0:
1214                if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1215                    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1216                        goto nla_put_failure;
1217                break;
1218        case GTP_V1:
1219                if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1220                    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1221                        goto nla_put_failure;
1222                break;
1223        }
1224        genlmsg_end(skb, genlh);
1225        return 0;
1226
1227nlmsg_failure:
1228nla_put_failure:
1229        genlmsg_cancel(skb, genlh);
1230        return -EMSGSIZE;
1231}
1232
1233static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1234{
1235        struct sk_buff *msg;
1236        int ret;
1237
1238        msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1239        if (!msg)
1240                return -ENOMEM;
1241
1242        ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1243        if (ret < 0) {
1244                nlmsg_free(msg);
1245                return ret;
1246        }
1247
1248        ret = genlmsg_multicast_netns(&gtp_genl_family, dev_net(pctx->dev), msg,
1249                                      0, GTP_GENL_MCGRP, GFP_ATOMIC);
1250        return ret;
1251}
1252
1253static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1254{
1255        struct pdp_ctx *pctx = NULL;
1256        struct sk_buff *skb2;
1257        int err;
1258
1259        if (!info->attrs[GTPA_VERSION])
1260                return -EINVAL;
1261
1262        rcu_read_lock();
1263
1264        pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1265        if (IS_ERR(pctx)) {
1266                err = PTR_ERR(pctx);
1267                goto err_unlock;
1268        }
1269
1270        skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1271        if (skb2 == NULL) {
1272                err = -ENOMEM;
1273                goto err_unlock;
1274        }
1275
1276        err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1277                                 0, info->nlhdr->nlmsg_type, pctx);
1278        if (err < 0)
1279                goto err_unlock_free;
1280
1281        rcu_read_unlock();
1282        return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1283
1284err_unlock_free:
1285        kfree_skb(skb2);
1286err_unlock:
1287        rcu_read_unlock();
1288        return err;
1289}
1290
1291static int gtp_genl_dump_pdp(struct sk_buff *skb,
1292                                struct netlink_callback *cb)
1293{
1294        struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1295        int i, j, bucket = cb->args[0], skip = cb->args[1];
1296        struct net *net = sock_net(skb->sk);
1297        struct pdp_ctx *pctx;
1298        struct gtp_net *gn;
1299
1300        gn = net_generic(net, gtp_net_id);
1301
1302        if (cb->args[4])
1303                return 0;
1304
1305        rcu_read_lock();
1306        list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1307                if (last_gtp && last_gtp != gtp)
1308                        continue;
1309                else
1310                        last_gtp = NULL;
1311
1312                for (i = bucket; i < gtp->hash_size; i++) {
1313                        j = 0;
1314                        hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
1315                                                 hlist_tid) {
1316                                if (j >= skip &&
1317                                    gtp_genl_fill_info(skb,
1318                                            NETLINK_CB(cb->skb).portid,
1319                                            cb->nlh->nlmsg_seq,
1320                                            NLM_F_MULTI,
1321                                            cb->nlh->nlmsg_type, pctx)) {
1322                                        cb->args[0] = i;
1323                                        cb->args[1] = j;
1324                                        cb->args[2] = (unsigned long)gtp;
1325                                        goto out;
1326                                }
1327                                j++;
1328                        }
1329                        skip = 0;
1330                }
1331                bucket = 0;
1332        }
1333        cb->args[4] = 1;
1334out:
1335        rcu_read_unlock();
1336        return skb->len;
1337}
1338
1339static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1340        [GTPA_LINK]             = { .type = NLA_U32, },
1341        [GTPA_VERSION]          = { .type = NLA_U32, },
1342        [GTPA_TID]              = { .type = NLA_U64, },
1343        [GTPA_PEER_ADDRESS]     = { .type = NLA_U32, },
1344        [GTPA_MS_ADDRESS]       = { .type = NLA_U32, },
1345        [GTPA_FLOW]             = { .type = NLA_U16, },
1346        [GTPA_NET_NS_FD]        = { .type = NLA_U32, },
1347        [GTPA_I_TEI]            = { .type = NLA_U32, },
1348        [GTPA_O_TEI]            = { .type = NLA_U32, },
1349};
1350
1351static const struct genl_small_ops gtp_genl_ops[] = {
1352        {
1353                .cmd = GTP_CMD_NEWPDP,
1354                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1355                .doit = gtp_genl_new_pdp,
1356                .flags = GENL_ADMIN_PERM,
1357        },
1358        {
1359                .cmd = GTP_CMD_DELPDP,
1360                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1361                .doit = gtp_genl_del_pdp,
1362                .flags = GENL_ADMIN_PERM,
1363        },
1364        {
1365                .cmd = GTP_CMD_GETPDP,
1366                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1367                .doit = gtp_genl_get_pdp,
1368                .dumpit = gtp_genl_dump_pdp,
1369                .flags = GENL_ADMIN_PERM,
1370        },
1371};
1372
1373static struct genl_family gtp_genl_family __ro_after_init = {
1374        .name           = "gtp",
1375        .version        = 0,
1376        .hdrsize        = 0,
1377        .maxattr        = GTPA_MAX,
1378        .policy = gtp_genl_policy,
1379        .netnsok        = true,
1380        .module         = THIS_MODULE,
1381        .small_ops      = gtp_genl_ops,
1382        .n_small_ops    = ARRAY_SIZE(gtp_genl_ops),
1383        .mcgrps         = gtp_genl_mcgrps,
1384        .n_mcgrps       = ARRAY_SIZE(gtp_genl_mcgrps),
1385};
1386
1387static int __net_init gtp_net_init(struct net *net)
1388{
1389        struct gtp_net *gn = net_generic(net, gtp_net_id);
1390
1391        INIT_LIST_HEAD(&gn->gtp_dev_list);
1392        return 0;
1393}
1394
1395static void __net_exit gtp_net_exit(struct net *net)
1396{
1397        struct gtp_net *gn = net_generic(net, gtp_net_id);
1398        struct gtp_dev *gtp;
1399        LIST_HEAD(list);
1400
1401        rtnl_lock();
1402        list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1403                gtp_dellink(gtp->dev, &list);
1404
1405        unregister_netdevice_many(&list);
1406        rtnl_unlock();
1407}
1408
1409static struct pernet_operations gtp_net_ops = {
1410        .init   = gtp_net_init,
1411        .exit   = gtp_net_exit,
1412        .id     = &gtp_net_id,
1413        .size   = sizeof(struct gtp_net),
1414};
1415
1416static int __init gtp_init(void)
1417{
1418        int err;
1419
1420        get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1421
1422        err = rtnl_link_register(&gtp_link_ops);
1423        if (err < 0)
1424                goto error_out;
1425
1426        err = genl_register_family(&gtp_genl_family);
1427        if (err < 0)
1428                goto unreg_rtnl_link;
1429
1430        err = register_pernet_subsys(&gtp_net_ops);
1431        if (err < 0)
1432                goto unreg_genl_family;
1433
1434        pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1435                sizeof(struct pdp_ctx));
1436        return 0;
1437
1438unreg_genl_family:
1439        genl_unregister_family(&gtp_genl_family);
1440unreg_rtnl_link:
1441        rtnl_link_unregister(&gtp_link_ops);
1442error_out:
1443        pr_err("error loading GTP module loaded\n");
1444        return err;
1445}
1446late_initcall(gtp_init);
1447
1448static void __exit gtp_fini(void)
1449{
1450        genl_unregister_family(&gtp_genl_family);
1451        rtnl_link_unregister(&gtp_link_ops);
1452        unregister_pernet_subsys(&gtp_net_ops);
1453
1454        pr_info("GTP module unloaded\n");
1455}
1456module_exit(gtp_fini);
1457
1458MODULE_LICENSE("GPL");
1459MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1460MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1461MODULE_ALIAS_RTNL_LINK("gtp");
1462MODULE_ALIAS_GENL_FAMILY("gtp");
1463