/* GTP according to GSM TS 09.60 / 3GPP TS 29.060 * * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> * * Author: Harald Welte <hwelte@sysmocom.de> * Pablo Neira Ayuso <pablo@netfilter.org> * Andreas Schultz <aschultz@travelping.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/skbuff.h> #include <linux/udp.h> #include <linux/rculist.h> #include <linux/jhash.h> #include <linux/if_tunnel.h> #include <linux/net.h> #include <linux/file.h> #include <linux/gtp.h> #include <net/net_namespace.h> #include <net/protocol.h> #include <net/ip.h> #include <net/udp.h> #include <net/udp_tunnel.h> #include <net/icmp.h> #include <net/xfrm.h> #include <net/genetlink.h> #include <net/netns/generic.h> #include <net/gtp.h> /* An active session for the subscriber. */ struct pdp_ctx { struct hlist_node hlist_tid; struct hlist_node hlist_addr; union { u64 tid; struct { u64 tid; u16 flow; } v0; struct { u32 i_tei; u32 o_tei; } v1; } u; u8 gtp_version; u16 af; struct in_addr ms_addr_ip4; struct in_addr sgsn_addr_ip4; atomic_t tx_seq; struct rcu_head rcu_head; }; /* One instance of the GTP device. */ struct gtp_dev { struct list_head list; struct socket *sock0; struct socket *sock1u; struct net *net; struct net_device *dev; unsigned int hash_size; struct hlist_head *tid_hash; struct hlist_head *addr_hash; }; static int gtp_net_id __read_mostly; struct gtp_net { struct list_head gtp_dev_list; }; static u32 gtp_h_initval; static inline u32 gtp0_hashfn(u64 tid) { u32 *tid32 = (u32 *) &tid; return jhash_2words(tid32[0], tid32[1], gtp_h_initval); } static inline u32 gtp1u_hashfn(u32 tid) { return jhash_1word(tid, gtp_h_initval); } static inline u32 ipv4_hashfn(__be32 ip) { return jhash_1word((__force u32)ip, gtp_h_initval); } /* Resolve a PDP context structure based on the 64bit TID. */ static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_tid) { if (pdp->gtp_version == GTP_V0 && pdp->u.v0.tid == tid) return pdp; } return NULL; } /* Resolve a PDP context structure based on the 32bit TEI. */ static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_tid) { if (pdp->gtp_version == GTP_V1 && pdp->u.v1.i_tei == tid) return pdp; } return NULL; } /* Resolve a PDP context based on IPv4 address of MS. */ static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) { struct hlist_head *head; struct pdp_ctx *pdp; head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size]; hlist_for_each_entry_rcu(pdp, head, hlist_addr) { if (pdp->af == AF_INET && pdp->ms_addr_ip4.s_addr == ms_addr) return pdp; } return NULL; } static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, unsigned int hdrlen) { struct iphdr *iph; if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr))) return false; iph = (struct iphdr *)(skb->data + hdrlen + sizeof(struct iphdr)); return iph->saddr != pctx->ms_addr_ip4.s_addr; } /* Check if the inner IP source address in this packet is assigned to any * existing mobile subscriber. */ static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx, unsigned int hdrlen) { switch (ntohs(skb->protocol)) { case ETH_P_IP: return gtp_check_src_ms_ipv4(skb, pctx, hdrlen); } return false; } /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb, bool xnet) { unsigned int hdrlen = sizeof(struct udphdr) + sizeof(struct gtp0_header); struct gtp0_header *gtp0; struct pdp_ctx *pctx; int ret = 0; if (!pskb_may_pull(skb, hdrlen)) return -1; gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); if ((gtp0->flags >> 5) != GTP_V0) return 1; if (gtp0->type != GTP_TPDU) return 1; rcu_read_lock(); pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid)); if (!pctx) { netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); ret = -1; goto out_rcu; } if (!gtp_check_src_ms(skb, pctx, hdrlen)) { netdev_dbg(gtp->dev, "No PDP ctx for this MS\n"); ret = -1; goto out_rcu; } rcu_read_unlock(); /* Get rid of the GTP + UDP headers. */ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet); out_rcu: rcu_read_unlock(); return ret; } static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb, bool xnet) { unsigned int hdrlen = sizeof(struct udphdr) + sizeof(struct gtp1_header); struct gtp1_header *gtp1; struct pdp_ctx *pctx; int ret = 0; if (!pskb_may_pull(skb, hdrlen)) return -1; gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); if ((gtp1->flags >> 5) != GTP_V1) return 1; if (gtp1->type != GTP_TPDU) return 1; /* From 29.060: "This field shall be present if and only if any one or * more of the S, PN and E flags are set.". * * If any of the bit is set, then the remaining ones also have to be * set. */ if (gtp1->flags & GTP1_F_MASK) hdrlen += 4; /* Make sure the header is larger enough, including extensions. */ if (!pskb_may_pull(skb, hdrlen)) return -1; gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); rcu_read_lock(); pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid)); if (!pctx) { netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb); ret = -1; goto out_rcu; } if (!gtp_check_src_ms(skb, pctx, hdrlen)) { netdev_dbg(gtp->dev, "No PDP ctx for this MS\n"); ret = -1; goto out_rcu; } rcu_read_unlock(); /* Get rid of the GTP + UDP headers. */ return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet); out_rcu: rcu_read_unlock(); return ret; } static void gtp_encap_disable(struct gtp_dev *gtp) { if (gtp->sock0 && gtp->sock0->sk) { udp_sk(gtp->sock0->sk)->encap_type = 0; rcu_assign_sk_user_data(gtp->sock0->sk, NULL); } if (gtp->sock1u && gtp->sock1u->sk) { udp_sk(gtp->sock1u->sk)->encap_type = 0; rcu_assign_sk_user_data(gtp->sock1u->sk, NULL); } gtp->sock0 = NULL; gtp->sock1u = NULL; } static void gtp_encap_destroy(struct sock *sk) { struct gtp_dev *gtp; gtp = rcu_dereference_sk_user_data(sk); if (gtp) gtp_encap_disable(gtp); } /* UDP encapsulation receive handler. See net/ipv4/udp.c. * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. */ static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) { struct pcpu_sw_netstats *stats; struct gtp_dev *gtp; bool xnet; int ret; gtp = rcu_dereference_sk_user_data(sk); if (!gtp) return 1; netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk); xnet = !net_eq(gtp->net, dev_net(gtp->dev)); switch (udp_sk(sk)->encap_type) { case UDP_ENCAP_GTP0: netdev_dbg(gtp->dev, "received GTP0 packet\n"); ret = gtp0_udp_encap_recv(gtp, skb, xnet); break; case UDP_ENCAP_GTP1U: netdev_dbg(gtp->dev, "received GTP1U packet\n"); ret = gtp1u_udp_encap_recv(gtp, skb, xnet); break; default: ret = -1; /* Shouldn't happen. */ } switch (ret) { case 1: netdev_dbg(gtp->dev, "pass up to the process\n"); return 1; case 0: netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n"); break; case -1: netdev_dbg(gtp->dev, "GTP packet has been dropped\n"); kfree_skb(skb); return 0; } /* Now that the UDP and the GTP header have been removed, set up the * new network header. This is required by the upper layer to * calculate the transport header. */ skb_reset_network_header(skb); skb->dev = gtp->dev; stats = this_cpu_ptr(gtp->dev->tstats); u64_stats_update_begin(&stats->syncp); stats->rx_packets++; stats->rx_bytes += skb->len; u64_stats_update_end(&stats->syncp); netif_rx(skb); return 0; } static int gtp_dev_init(struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); gtp->dev = dev; dev->tstats = alloc_percpu(struct pcpu_sw_netstats); if (!dev->tstats) return -ENOMEM; return 0; } static void gtp_dev_uninit(struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); gtp_encap_disable(gtp); free_percpu(dev->tstats); } static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4, const struct sock *sk, __be32 daddr) { memset(fl4, 0, sizeof(*fl4)); fl4->flowi4_oif = sk->sk_bound_dev_if; fl4->daddr = daddr; fl4->saddr = inet_sk(sk)->inet_saddr; fl4->flowi4_tos = RT_CONN_FLAGS(sk); fl4->flowi4_proto = sk->sk_protocol; return ip_route_output_key(net, fl4); } static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) { int payload_len = skb->len; struct gtp0_header *gtp0; gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0)); gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ gtp0->type = GTP_TPDU; gtp0->length = htons(payload_len); gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); gtp0->flow = htons(pctx->u.v0.flow); gtp0->number = 0xff; gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; gtp0->tid = cpu_to_be64(pctx->u.v0.tid); } static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx) { int payload_len = skb->len; struct gtp1_header *gtp1; gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1)); /* Bits 8 7 6 5 4 3 2 1 * +--+--+--+--+--+--+--+--+ * |version |PT| 1| E| S|PN| * +--+--+--+--+--+--+--+--+ * 0 0 1 1 1 0 0 0 */ gtp1->flags = 0x38; /* v1, GTP-non-prime. */ gtp1->type = GTP_TPDU; gtp1->length = htons(payload_len); gtp1->tid = htonl(pctx->u.v1.o_tei); /* TODO: Suppport for extension header, sequence number and N-PDU. * Update the length field if any of them is available. */ } struct gtp_pktinfo { struct sock *sk; struct iphdr *iph; struct flowi4 fl4; struct rtable *rt; struct pdp_ctx *pctx; struct net_device *dev; __be16 gtph_port; }; static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo) { switch (pktinfo->pctx->gtp_version) { case GTP_V0: pktinfo->gtph_port = htons(GTP0_PORT); gtp0_push_header(skb, pktinfo->pctx); break; case GTP_V1: pktinfo->gtph_port = htons(GTP1U_PORT); gtp1_push_header(skb, pktinfo->pctx); break; } } static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, struct sock *sk, struct iphdr *iph, struct pdp_ctx *pctx, struct rtable *rt, struct flowi4 *fl4, struct net_device *dev) { pktinfo->sk = sk; pktinfo->iph = iph; pktinfo->pctx = pctx; pktinfo->rt = rt; pktinfo->fl4 = *fl4; pktinfo->dev = dev; } static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, struct gtp_pktinfo *pktinfo) { struct gtp_dev *gtp = netdev_priv(dev); struct pdp_ctx *pctx; struct rtable *rt; struct flowi4 fl4; struct iphdr *iph; struct sock *sk; __be16 df; int mtu; /* Read the IP destination address and resolve the PDP context. * Prepend PDP header with TEI/TID from PDP ctx. */ iph = ip_hdr(skb); pctx = ipv4_pdp_find(gtp, iph->daddr); if (!pctx) { netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n", &iph->daddr); return -ENOENT; } netdev_dbg(dev, "found PDP context %p\n", pctx); switch (pctx->gtp_version) { case GTP_V0: if (gtp->sock0) sk = gtp->sock0->sk; else sk = NULL; break; case GTP_V1: if (gtp->sock1u) sk = gtp->sock1u->sk; else sk = NULL; break; default: return -ENOENT; } if (!sk) { netdev_dbg(dev, "no userspace socket is available, skip\n"); return -ENOENT; } rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk, pctx->sgsn_addr_ip4.s_addr); if (IS_ERR(rt)) { netdev_dbg(dev, "no route to SSGN %pI4\n", &pctx->sgsn_addr_ip4.s_addr); dev->stats.tx_carrier_errors++; goto err; } if (rt->dst.dev == dev) { netdev_dbg(dev, "circular route to SSGN %pI4\n", &pctx->sgsn_addr_ip4.s_addr); dev->stats.collisions++; goto err_rt; } skb_dst_drop(skb); /* This is similar to tnl_update_pmtu(). */ df = iph->frag_off; if (df) { mtu = dst_mtu(&rt->dst) - dev->hard_header_len - sizeof(struct iphdr) - sizeof(struct udphdr); switch (pctx->gtp_version) { case GTP_V0: mtu -= sizeof(struct gtp0_header); break; case GTP_V1: mtu -= sizeof(struct gtp1_header); break; } } else { mtu = dst_mtu(&rt->dst); } rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu); if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) && mtu < ntohs(iph->tot_len)) { netdev_dbg(dev, "packet too big, fragmentation needed\n"); memset(IPCB(skb), 0, sizeof(*IPCB(skb))); icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, htonl(mtu)); goto err_rt; } gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev); gtp_push_header(skb, pktinfo); return 0; err_rt: ip_rt_put(rt); err: return -EBADMSG; } static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned int proto = ntohs(skb->protocol); struct gtp_pktinfo pktinfo; int err; /* Ensure there is sufficient headroom. */ if (skb_cow_head(skb, dev->needed_headroom)) goto tx_err; skb_reset_inner_headers(skb); /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ rcu_read_lock(); switch (proto) { case ETH_P_IP: err = gtp_build_skb_ip4(skb, dev, &pktinfo); break; default: err = -EOPNOTSUPP; break; } rcu_read_unlock(); if (err < 0) goto tx_err; switch (proto) { case ETH_P_IP: netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n", &pktinfo.iph->saddr, &pktinfo.iph->daddr); udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb, pktinfo.fl4.saddr, pktinfo.fl4.daddr, pktinfo.iph->tos, ip4_dst_hoplimit(&pktinfo.rt->dst), htons(IP_DF), pktinfo.gtph_port, pktinfo.gtph_port, true, false); break; } return NETDEV_TX_OK; tx_err: dev->stats.tx_errors++; dev_kfree_skb(skb); return NETDEV_TX_OK; } static const struct net_device_ops gtp_netdev_ops = { .ndo_init = gtp_dev_init, .ndo_uninit = gtp_dev_uninit, .ndo_start_xmit = gtp_dev_xmit, .ndo_get_stats64 = ip_tunnel_get_stats64, }; static void gtp_link_setup(struct net_device *dev) { dev->netdev_ops = >p_netdev_ops; dev->destructor = free_netdev; dev->hard_header_len = 0; dev->addr_len = 0; /* Zero header length. */ dev->type = ARPHRD_NONE; dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; dev->priv_flags |= IFF_NO_QUEUE; dev->features |= NETIF_F_LLTX; netif_keep_dst(dev); /* Assume largest header, ie. GTPv0. */ dev->needed_headroom = LL_MAX_HEADER + sizeof(struct iphdr) + sizeof(struct udphdr) + sizeof(struct gtp0_header); } static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); static void gtp_hashtable_free(struct gtp_dev *gtp); static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp, int fd_gtp0, int fd_gtp1, struct net *src_net); static int gtp_newlink(struct net *src_net, struct net_device *dev, struct nlattr *tb[], struct nlattr *data[]) { int hashsize, err, fd0, fd1; struct gtp_dev *gtp; struct gtp_net *gn; if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1]) return -EINVAL; gtp = netdev_priv(dev); fd0 = nla_get_u32(data[IFLA_GTP_FD0]); fd1 = nla_get_u32(data[IFLA_GTP_FD1]); err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net); if (err < 0) goto out_err; if (!data[IFLA_GTP_PDP_HASHSIZE]) hashsize = 1024; else hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]); err = gtp_hashtable_new(gtp, hashsize); if (err < 0) goto out_encap; err = register_netdevice(dev); if (err < 0) { netdev_dbg(dev, "failed to register new netdev %d\n", err); goto out_hashtable; } gn = net_generic(dev_net(dev), gtp_net_id); list_add_rcu(>p->list, &gn->gtp_dev_list); netdev_dbg(dev, "registered new GTP interface\n"); return 0; out_hashtable: gtp_hashtable_free(gtp); out_encap: gtp_encap_disable(gtp); out_err: return err; } static void gtp_dellink(struct net_device *dev, struct list_head *head) { struct gtp_dev *gtp = netdev_priv(dev); gtp_encap_disable(gtp); gtp_hashtable_free(gtp); list_del_rcu(>p->list); unregister_netdevice_queue(dev, head); } static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { [IFLA_GTP_FD0] = { .type = NLA_U32 }, [IFLA_GTP_FD1] = { .type = NLA_U32 }, [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, }; static int gtp_validate(struct nlattr *tb[], struct nlattr *data[]) { if (!data) return -EINVAL; return 0; } static size_t gtp_get_size(const struct net_device *dev) { return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */ } static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) { struct gtp_dev *gtp = netdev_priv(dev); if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size)) goto nla_put_failure; return 0; nla_put_failure: return -EMSGSIZE; } static struct rtnl_link_ops gtp_link_ops __read_mostly = { .kind = "gtp", .maxtype = IFLA_GTP_MAX, .policy = gtp_policy, .priv_size = sizeof(struct gtp_dev), .setup = gtp_link_setup, .validate = gtp_validate, .newlink = gtp_newlink, .dellink = gtp_dellink, .get_size = gtp_get_size, .fill_info = gtp_fill_info, }; static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[]) { struct net *net; /* Examine the link attributes and figure out which network namespace * we are talking about. */ if (tb[GTPA_NET_NS_FD]) net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD])); else net = get_net(src_net); return net; } static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) { int i; gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL); if (gtp->addr_hash == NULL) return -ENOMEM; gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL); if (gtp->tid_hash == NULL) goto err1; gtp->hash_size = hsize; for (i = 0; i < hsize; i++) { INIT_HLIST_HEAD(>p->addr_hash[i]); INIT_HLIST_HEAD(>p->tid_hash[i]); } return 0; err1: kfree(gtp->addr_hash); return -ENOMEM; } static void gtp_hashtable_free(struct gtp_dev *gtp) { struct pdp_ctx *pctx; int i; for (i = 0; i < gtp->hash_size; i++) { hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) { hlist_del_rcu(&pctx->hlist_tid); hlist_del_rcu(&pctx->hlist_addr); kfree_rcu(pctx, rcu_head); } } synchronize_rcu(); kfree(gtp->addr_hash); kfree(gtp->tid_hash); } static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp, int fd_gtp0, int fd_gtp1, struct net *src_net) { struct udp_tunnel_sock_cfg tuncfg = {NULL}; struct socket *sock0, *sock1u; int err; netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1); sock0 = sockfd_lookup(fd_gtp0, &err); if (sock0 == NULL) { netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0); return -ENOENT; } if (sock0->sk->sk_protocol != IPPROTO_UDP) { netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0); err = -EINVAL; goto err1; } sock1u = sockfd_lookup(fd_gtp1, &err); if (sock1u == NULL) { netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1); err = -ENOENT; goto err1; } if (sock1u->sk->sk_protocol != IPPROTO_UDP) { netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1); err = -EINVAL; goto err2; } netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u); gtp->sock0 = sock0; gtp->sock1u = sock1u; gtp->net = src_net; tuncfg.sk_user_data = gtp; tuncfg.encap_rcv = gtp_encap_recv; tuncfg.encap_destroy = gtp_encap_destroy; tuncfg.encap_type = UDP_ENCAP_GTP0; setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg); tuncfg.encap_type = UDP_ENCAP_GTP1U; setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg); err = 0; err2: sockfd_put(sock1u); err1: sockfd_put(sock0); return err; } static struct net_device *gtp_find_dev(struct net *net, int ifindex) { struct gtp_net *gn = net_generic(net, gtp_net_id); struct gtp_dev *gtp; list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { if (ifindex == gtp->dev->ifindex) return gtp->dev; } return NULL; } static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) { pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); pctx->af = AF_INET; pctx->sgsn_addr_ip4.s_addr = nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]); pctx->ms_addr_ip4.s_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); switch (pctx->gtp_version) { case GTP_V0: /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow * label needs to be the same for uplink and downlink packets, * so let's annotate this. */ pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]); pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]); break; case GTP_V1: pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]); pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]); break; default: break; } } static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info) { struct gtp_dev *gtp = netdev_priv(dev); u32 hash_ms, hash_tid = 0; struct pdp_ctx *pctx; bool found = false; __be32 ms_addr; ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size; hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) { if (pctx->ms_addr_ip4.s_addr == ms_addr) { found = true; break; } } if (found) { if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) return -EEXIST; if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) return -EOPNOTSUPP; ipv4_pdp_fill(pctx, info); if (pctx->gtp_version == GTP_V0) netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n", pctx->u.v0.tid, pctx); else if (pctx->gtp_version == GTP_V1) netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); return 0; } pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL); if (pctx == NULL) return -ENOMEM; ipv4_pdp_fill(pctx, info); atomic_set(&pctx->tx_seq, 0); switch (pctx->gtp_version) { case GTP_V0: /* TS 09.60: "The flow label identifies unambiguously a GTP * flow.". We use the tid for this instead, I cannot find a * situation in which this doesn't unambiguosly identify the * PDP context. */ hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size; break; case GTP_V1: hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size; break; } hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]); hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]); switch (pctx->gtp_version) { case GTP_V0: netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n", pctx->u.v0.tid, &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx); break; case GTP_V1: netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx); break; } return 0; } static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) { struct net_device *dev; struct net *net; if (!info->attrs[GTPA_VERSION] || !info->attrs[GTPA_LINK] || !info->attrs[GTPA_SGSN_ADDRESS] || !info->attrs[GTPA_MS_ADDRESS]) return -EINVAL; switch (nla_get_u32(info->attrs[GTPA_VERSION])) { case GTP_V0: if (!info->attrs[GTPA_TID] || !info->attrs[GTPA_FLOW]) return -EINVAL; break; case GTP_V1: if (!info->attrs[GTPA_I_TEI] || !info->attrs[GTPA_O_TEI]) return -EINVAL; break; default: return -EINVAL; } net = gtp_genl_get_net(sock_net(skb->sk), info->attrs); if (IS_ERR(net)) return PTR_ERR(net); /* Check if there's an existing gtpX device to configure */ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK])); if (dev == NULL) { put_net(net); return -ENODEV; } put_net(net); return ipv4_pdp_add(dev, info); } static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) { struct net_device *dev; struct pdp_ctx *pctx; struct gtp_dev *gtp; struct net *net; if (!info->attrs[GTPA_VERSION] || !info->attrs[GTPA_LINK]) return -EINVAL; net = gtp_genl_get_net(sock_net(skb->sk), info->attrs); if (IS_ERR(net)) return PTR_ERR(net); /* Check if there's an existing gtpX device to configure */ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK])); if (dev == NULL) { put_net(net); return -ENODEV; } put_net(net); gtp = netdev_priv(dev); switch (nla_get_u32(info->attrs[GTPA_VERSION])) { case GTP_V0: if (!info->attrs[GTPA_TID]) return -EINVAL; pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID])); break; case GTP_V1: if (!info->attrs[GTPA_I_TEI]) return -EINVAL; pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI])); break; default: return -EINVAL; } if (pctx == NULL) return -ENOENT; if (pctx->gtp_version == GTP_V0) netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n", pctx->u.v0.tid, pctx); else if (pctx->gtp_version == GTP_V1) netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n", pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); hlist_del_rcu(&pctx->hlist_tid); hlist_del_rcu(&pctx->hlist_addr); kfree_rcu(pctx, rcu_head); return 0; } static struct genl_family gtp_genl_family = { .id = GENL_ID_GENERATE, .name = "gtp", .version = 0, .hdrsize = 0, .maxattr = GTPA_MAX, .netnsok = true, }; static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, u32 type, struct pdp_ctx *pctx) { void *genlh; genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0, type); if (genlh == NULL) goto nlmsg_failure; if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) || nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) || nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr)) goto nla_put_failure; switch (pctx->gtp_version) { case GTP_V0: if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) || nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow)) goto nla_put_failure; break; case GTP_V1: if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) || nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei)) goto nla_put_failure; break; } genlmsg_end(skb, genlh); return 0; nlmsg_failure: nla_put_failure: genlmsg_cancel(skb, genlh); return -EMSGSIZE; } static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) { struct pdp_ctx *pctx = NULL; struct net_device *dev; struct sk_buff *skb2; struct gtp_dev *gtp; u32 gtp_version; struct net *net; int err; if (!info->attrs[GTPA_VERSION] || !info->attrs[GTPA_LINK]) return -EINVAL; gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]); switch (gtp_version) { case GTP_V0: case GTP_V1: break; default: return -EINVAL; } net = gtp_genl_get_net(sock_net(skb->sk), info->attrs); if (IS_ERR(net)) return PTR_ERR(net); /* Check if there's an existing gtpX device to configure */ dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK])); if (dev == NULL) { put_net(net); return -ENODEV; } put_net(net); gtp = netdev_priv(dev); rcu_read_lock(); if (gtp_version == GTP_V0 && info->attrs[GTPA_TID]) { u64 tid = nla_get_u64(info->attrs[GTPA_TID]); pctx = gtp0_pdp_find(gtp, tid); } else if (gtp_version == GTP_V1 && info->attrs[GTPA_I_TEI]) { u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]); pctx = gtp1_pdp_find(gtp, tid); } else if (info->attrs[GTPA_MS_ADDRESS]) { __be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]); pctx = ipv4_pdp_find(gtp, ip); } if (pctx == NULL) { err = -ENOENT; goto err_unlock; } skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); if (skb2 == NULL) { err = -ENOMEM; goto err_unlock; } err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq, info->nlhdr->nlmsg_type, pctx); if (err < 0) goto err_unlock_free; rcu_read_unlock(); return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid); err_unlock_free: kfree_skb(skb2); err_unlock: rcu_read_unlock(); return err; } static int gtp_genl_dump_pdp(struct sk_buff *skb, struct netlink_callback *cb) { struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; struct net *net = sock_net(skb->sk); struct gtp_net *gn = net_generic(net, gtp_net_id); unsigned long tid = cb->args[1]; int i, k = cb->args[0], ret; struct pdp_ctx *pctx; if (cb->args[4]) return 0; list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { if (last_gtp && last_gtp != gtp) continue; else last_gtp = NULL; for (i = k; i < gtp->hash_size; i++) { hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) { if (tid && tid != pctx->u.tid) continue; else tid = 0; ret = gtp_genl_fill_info(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, cb->nlh->nlmsg_type, pctx); if (ret < 0) { cb->args[0] = i; cb->args[1] = pctx->u.tid; cb->args[2] = (unsigned long)gtp; goto out; } } } } cb->args[4] = 1; out: return skb->len; } static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { [GTPA_LINK] = { .type = NLA_U32, }, [GTPA_VERSION] = { .type = NLA_U32, }, [GTPA_TID] = { .type = NLA_U64, }, [GTPA_SGSN_ADDRESS] = { .type = NLA_U32, }, [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, [GTPA_FLOW] = { .type = NLA_U16, }, [GTPA_NET_NS_FD] = { .type = NLA_U32, }, [GTPA_I_TEI] = { .type = NLA_U32, }, [GTPA_O_TEI] = { .type = NLA_U32, }, }; static const struct genl_ops gtp_genl_ops[] = { { .cmd = GTP_CMD_NEWPDP, .doit = gtp_genl_new_pdp, .policy = gtp_genl_policy, .flags = GENL_ADMIN_PERM, }, { .cmd = GTP_CMD_DELPDP, .doit = gtp_genl_del_pdp, .policy = gtp_genl_policy, .flags = GENL_ADMIN_PERM, }, { .cmd = GTP_CMD_GETPDP, .doit = gtp_genl_get_pdp, .dumpit = gtp_genl_dump_pdp, .policy = gtp_genl_policy, .flags = GENL_ADMIN_PERM, }, }; static int __net_init gtp_net_init(struct net *net) { struct gtp_net *gn = net_generic(net, gtp_net_id); INIT_LIST_HEAD(&gn->gtp_dev_list); return 0; } static void __net_exit gtp_net_exit(struct net *net) { struct gtp_net *gn = net_generic(net, gtp_net_id); struct gtp_dev *gtp; LIST_HEAD(list); rtnl_lock(); list_for_each_entry(gtp, &gn->gtp_dev_list, list) gtp_dellink(gtp->dev, &list); unregister_netdevice_many(&list); rtnl_unlock(); } static struct pernet_operations gtp_net_ops = { .init = gtp_net_init, .exit = gtp_net_exit, .id = >p_net_id, .size = sizeof(struct gtp_net), }; static int __init gtp_init(void) { int err; get_random_bytes(>p_h_initval, sizeof(gtp_h_initval)); err = rtnl_link_register(>p_link_ops); if (err < 0) goto error_out; err = genl_register_family_with_ops(>p_genl_family, gtp_genl_ops); if (err < 0) goto unreg_rtnl_link; err = register_pernet_subsys(>p_net_ops); if (err < 0) goto unreg_genl_family; pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n", sizeof(struct pdp_ctx)); return 0; unreg_genl_family: genl_unregister_family(>p_genl_family); unreg_rtnl_link: rtnl_link_unregister(>p_link_ops); error_out: pr_err("error loading GTP module loaded\n"); return err; } late_initcall(gtp_init); static void __exit gtp_fini(void) { unregister_pernet_subsys(>p_net_ops); genl_unregister_family(>p_genl_family); rtnl_link_unregister(>p_link_ops); pr_info("GTP module unloaded\n"); } module_exit(gtp_fini); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>"); MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic"); MODULE_ALIAS_RTNL_LINK("gtp");