1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * PFCP according to 3GPP TS 29.244 4 * 5 * Copyright (C) 2022, Intel Corporation. 6 */ 7 8 #include <linux/module.h> 9 #include <linux/netdevice.h> 10 #include <linux/rculist.h> 11 #include <linux/skbuff.h> 12 #include <linux/types.h> 13 14 #include <net/udp.h> 15 #include <net/udp_tunnel.h> 16 #include <net/pfcp.h> 17 18 struct pfcp_dev { 19 struct list_head list; 20 21 struct sock *sk; 22 struct net_device *dev; 23 struct net *net; 24 25 struct gro_cells gro_cells; 26 }; 27 28 static unsigned int pfcp_net_id __read_mostly; 29 30 struct pfcp_net { 31 struct list_head pfcp_dev_list; 32 struct mutex lock; 33 }; 34 35 static void 36 pfcp_session_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 37 struct pfcp_metadata *md) 38 { 39 struct pfcphdr_session *unparsed = pfcp_hdr_session(skb); 40 41 md->seid = unparsed->seid; 42 md->type = PFCP_TYPE_SESSION; 43 } 44 45 static void 46 pfcp_node_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 47 struct pfcp_metadata *md) 48 { 49 md->type = PFCP_TYPE_NODE; 50 } 51 52 static int pfcp_encap_recv(struct sock *sk, struct sk_buff *skb) 53 { 54 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 55 struct metadata_dst *tun_dst; 56 struct pfcp_metadata *md; 57 struct pfcphdr *unparsed; 58 struct pfcp_dev *pfcp; 59 60 if (unlikely(!pskb_may_pull(skb, PFCP_HLEN))) 61 goto drop; 62 63 pfcp = rcu_dereference_sk_user_data(sk); 64 if (unlikely(!pfcp)) 65 goto drop; 66 67 unparsed = pfcp_hdr(skb); 68 69 ip_tunnel_flags_zero(flags); 70 tun_dst = udp_tun_rx_dst(skb, sk->sk_family, flags, 0, 71 sizeof(*md)); 72 if (unlikely(!tun_dst)) 73 goto drop; 74 75 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 76 if (unlikely(!md)) 77 goto drop_dst; 78 79 if (unparsed->flags & PFCP_SEID_FLAG) 80 pfcp_session_recv(pfcp, skb, md); 81 else 82 pfcp_node_recv(pfcp, skb, md); 83 84 __set_bit(IP_TUNNEL_PFCP_OPT_BIT, tun_dst->u.tun_info.key.tun_flags); 85 tun_dst->u.tun_info.options_len = sizeof(*md); 86 87 if (unlikely(iptunnel_pull_header(skb, PFCP_HLEN, skb->protocol, 88 !net_eq(sock_net(sk), 89 dev_net(pfcp->dev))))) 90 goto drop_dst; 91 92 skb_dst_set(skb, (struct dst_entry *)tun_dst); 93 94 skb_reset_network_header(skb); 95 skb_reset_mac_header(skb); 96 skb->dev = pfcp->dev; 97 98 gro_cells_receive(&pfcp->gro_cells, skb); 99 100 return 0; 101 drop_dst: 102 dst_release(&tun_dst->dst); 103 drop: 104 kfree_skb(skb); 105 return 0; 106 } 107 108 static void pfcp_del_sock(struct pfcp_dev *pfcp) 109 { 110 if (!pfcp->sk) 111 return; 112 113 udp_tunnel_sock_release(pfcp->sk); 114 pfcp->sk = NULL; 115 } 116 117 static void pfcp_dev_uninit(struct net_device *dev) 118 { 119 struct pfcp_dev *pfcp = netdev_priv(dev); 120 121 gro_cells_destroy(&pfcp->gro_cells); 122 pfcp_del_sock(pfcp); 123 } 124 125 static int pfcp_dev_init(struct net_device *dev) 126 { 127 struct pfcp_dev *pfcp = netdev_priv(dev); 128 129 pfcp->dev = dev; 130 131 return gro_cells_init(&pfcp->gro_cells, dev); 132 } 133 134 static const struct net_device_ops pfcp_netdev_ops = { 135 .ndo_init = pfcp_dev_init, 136 .ndo_uninit = pfcp_dev_uninit, 137 .ndo_get_stats64 = dev_get_tstats64, 138 }; 139 140 static const struct device_type pfcp_type = { 141 .name = "pfcp", 142 }; 143 144 static void pfcp_link_setup(struct net_device *dev) 145 { 146 dev->netdev_ops = &pfcp_netdev_ops; 147 dev->needs_free_netdev = true; 148 SET_NETDEV_DEVTYPE(dev, &pfcp_type); 149 150 dev->hard_header_len = 0; 151 dev->addr_len = 0; 152 153 dev->type = ARPHRD_NONE; 154 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 155 dev->priv_flags |= IFF_NO_QUEUE; 156 157 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 158 netif_keep_dst(dev); 159 } 160 161 static struct sock *pfcp_create_sock(struct pfcp_dev *pfcp) 162 { 163 struct udp_tunnel_sock_cfg tuncfg = {}; 164 struct udp_port_cfg udp_conf = { 165 .local_ip.s_addr = htonl(INADDR_ANY), 166 .family = AF_INET, 167 }; 168 struct net *net = pfcp->net; 169 struct socket *sock; 170 int err; 171 172 udp_conf.local_udp_port = htons(PFCP_PORT); 173 174 err = udp_sock_create(net, &udp_conf, &sock); 175 if (err) 176 return ERR_PTR(err); 177 178 tuncfg.sk_user_data = pfcp; 179 tuncfg.encap_rcv = pfcp_encap_recv; 180 tuncfg.encap_type = 1; 181 182 setup_udp_tunnel_sock(net, sock->sk, &tuncfg); 183 184 return sock->sk; 185 } 186 187 static int pfcp_add_sock(struct pfcp_dev *pfcp) 188 { 189 pfcp->sk = pfcp_create_sock(pfcp); 190 191 return PTR_ERR_OR_ZERO(pfcp->sk); 192 } 193 194 static int pfcp_newlink(struct net_device *dev, 195 struct rtnl_newlink_params *params, 196 struct netlink_ext_ack *extack) 197 { 198 struct net *link_net = rtnl_newlink_link_net(params); 199 struct pfcp_dev *pfcp = netdev_priv(dev); 200 struct pfcp_net *pn; 201 int err; 202 203 pfcp->net = link_net; 204 205 err = pfcp_add_sock(pfcp); 206 if (err) { 207 netdev_dbg(dev, "failed to add pfcp socket %d\n", err); 208 goto exit_err; 209 } 210 211 err = register_netdevice(dev); 212 if (err) { 213 netdev_dbg(dev, "failed to register pfcp netdev %d\n", err); 214 goto exit_del_pfcp_sock; 215 } 216 217 pn = net_generic(link_net, pfcp_net_id); 218 219 mutex_lock(&pn->lock); 220 list_add(&pfcp->list, &pn->pfcp_dev_list); 221 mutex_unlock(&pn->lock); 222 223 netdev_dbg(dev, "registered new PFCP interface\n"); 224 225 return 0; 226 227 exit_del_pfcp_sock: 228 pfcp_del_sock(pfcp); 229 synchronize_rcu(); 230 exit_err: 231 pfcp->net = NULL; 232 return err; 233 } 234 235 static void __pfcp_dellink(struct net *net, struct net_device *dev, 236 struct list_head *head) 237 { 238 struct pfcp_dev *pfcp = netdev_priv(dev); 239 240 list_del_init(&pfcp->list); 241 unregister_netdevice_queue_net(net, dev, head); 242 } 243 244 static void pfcp_dellink(struct net_device *dev, struct list_head *head) 245 { 246 struct pfcp_dev *pfcp = netdev_priv(dev); 247 struct pfcp_net *pn; 248 249 pn = net_generic(pfcp->net, pfcp_net_id); 250 251 mutex_lock(&pn->lock); 252 if (!list_empty(&pfcp->list)) 253 __pfcp_dellink(dev_net(dev), dev, head); 254 mutex_unlock(&pn->lock); 255 } 256 257 static struct rtnl_link_ops pfcp_link_ops __read_mostly = { 258 .kind = "pfcp", 259 .priv_size = sizeof(struct pfcp_dev), 260 .setup = pfcp_link_setup, 261 .newlink = pfcp_newlink, 262 .dellink = pfcp_dellink, 263 }; 264 265 static int __net_init pfcp_net_init(struct net *net) 266 { 267 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 268 269 INIT_LIST_HEAD(&pn->pfcp_dev_list); 270 mutex_init(&pn->lock); 271 272 return 0; 273 } 274 275 static void __net_exit pfcp_net_exit_rtnl(struct net *net, 276 struct list_head *dev_to_kill) 277 { 278 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 279 struct pfcp_dev *pfcp, *pfcp_next; 280 281 mutex_lock(&pn->lock); 282 283 list_for_each_entry_safe(pfcp, pfcp_next, &pn->pfcp_dev_list, list) 284 __pfcp_dellink(net, pfcp->dev, dev_to_kill); 285 286 mutex_unlock(&pn->lock); 287 } 288 289 static struct pernet_operations pfcp_net_ops = { 290 .init = pfcp_net_init, 291 .exit_rtnl = pfcp_net_exit_rtnl, 292 .id = &pfcp_net_id, 293 .size = sizeof(struct pfcp_net), 294 }; 295 296 static int __init pfcp_init(void) 297 { 298 int err; 299 300 err = register_pernet_subsys(&pfcp_net_ops); 301 if (err) 302 goto exit_err; 303 304 err = rtnl_link_register(&pfcp_link_ops); 305 if (err) 306 goto exit_unregister_subsys; 307 return 0; 308 309 exit_unregister_subsys: 310 unregister_pernet_subsys(&pfcp_net_ops); 311 exit_err: 312 pr_err("loading PFCP module failed: err %d\n", err); 313 return err; 314 } 315 late_initcall(pfcp_init); 316 317 static void __exit pfcp_exit(void) 318 { 319 rtnl_link_unregister(&pfcp_link_ops); 320 unregister_pernet_subsys(&pfcp_net_ops); 321 322 pr_info("PFCP module unloaded\n"); 323 } 324 module_exit(pfcp_exit); 325 326 MODULE_LICENSE("GPL"); 327 MODULE_AUTHOR("Wojciech Drewek <wojciech.drewek@intel.com>"); 328 MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic"); 329 MODULE_ALIAS_RTNL_LINK("pfcp"); 330