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; 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; 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: 102 kfree_skb(skb); 103 return 0; 104 } 105 106 static void pfcp_del_sock(struct pfcp_dev *pfcp) 107 { 108 if (!pfcp->sk) 109 return; 110 111 udp_tunnel_sock_release(pfcp->sk); 112 pfcp->sk = NULL; 113 } 114 115 static void pfcp_dev_uninit(struct net_device *dev) 116 { 117 struct pfcp_dev *pfcp = netdev_priv(dev); 118 119 gro_cells_destroy(&pfcp->gro_cells); 120 pfcp_del_sock(pfcp); 121 } 122 123 static int pfcp_dev_init(struct net_device *dev) 124 { 125 struct pfcp_dev *pfcp = netdev_priv(dev); 126 127 pfcp->dev = dev; 128 129 return gro_cells_init(&pfcp->gro_cells, dev); 130 } 131 132 static const struct net_device_ops pfcp_netdev_ops = { 133 .ndo_init = pfcp_dev_init, 134 .ndo_uninit = pfcp_dev_uninit, 135 .ndo_get_stats64 = dev_get_tstats64, 136 }; 137 138 static const struct device_type pfcp_type = { 139 .name = "pfcp", 140 }; 141 142 static void pfcp_link_setup(struct net_device *dev) 143 { 144 dev->netdev_ops = &pfcp_netdev_ops; 145 dev->needs_free_netdev = true; 146 SET_NETDEV_DEVTYPE(dev, &pfcp_type); 147 148 dev->hard_header_len = 0; 149 dev->addr_len = 0; 150 151 dev->type = ARPHRD_NONE; 152 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 153 dev->priv_flags |= IFF_NO_QUEUE; 154 155 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; 156 netif_keep_dst(dev); 157 } 158 159 static struct sock *pfcp_create_sock(struct pfcp_dev *pfcp) 160 { 161 struct udp_tunnel_sock_cfg tuncfg = {}; 162 struct udp_port_cfg udp_conf = { 163 .local_ip.s_addr = htonl(INADDR_ANY), 164 .family = AF_INET, 165 }; 166 struct net *net = pfcp->net; 167 struct socket *sock; 168 int err; 169 170 udp_conf.local_udp_port = htons(PFCP_PORT); 171 172 err = udp_sock_create(net, &udp_conf, &sock); 173 if (err) 174 return ERR_PTR(err); 175 176 tuncfg.sk_user_data = pfcp; 177 tuncfg.encap_rcv = pfcp_encap_recv; 178 tuncfg.encap_type = 1; 179 180 setup_udp_tunnel_sock(net, sock->sk, &tuncfg); 181 182 return sock->sk; 183 } 184 185 static int pfcp_add_sock(struct pfcp_dev *pfcp) 186 { 187 pfcp->sk = pfcp_create_sock(pfcp); 188 189 return PTR_ERR_OR_ZERO(pfcp->sk); 190 } 191 192 static int pfcp_newlink(struct net_device *dev, 193 struct rtnl_newlink_params *params, 194 struct netlink_ext_ack *extack) 195 { 196 struct net *link_net = rtnl_newlink_link_net(params); 197 struct pfcp_dev *pfcp = netdev_priv(dev); 198 struct pfcp_net *pn; 199 int err; 200 201 pfcp->net = link_net; 202 203 err = pfcp_add_sock(pfcp); 204 if (err) { 205 netdev_dbg(dev, "failed to add pfcp socket %d\n", err); 206 goto exit_err; 207 } 208 209 err = register_netdevice(dev); 210 if (err) { 211 netdev_dbg(dev, "failed to register pfcp netdev %d\n", err); 212 goto exit_del_pfcp_sock; 213 } 214 215 pn = net_generic(link_net, pfcp_net_id); 216 217 mutex_lock(&pn->lock); 218 list_add(&pfcp->list, &pn->pfcp_dev_list); 219 mutex_unlock(&pn->lock); 220 221 netdev_dbg(dev, "registered new PFCP interface\n"); 222 223 return 0; 224 225 exit_del_pfcp_sock: 226 pfcp_del_sock(pfcp); 227 synchronize_rcu(); 228 exit_err: 229 pfcp->net = NULL; 230 return err; 231 } 232 233 static void __pfcp_dellink(struct net *net, struct net_device *dev, 234 struct list_head *head) 235 { 236 struct pfcp_dev *pfcp = netdev_priv(dev); 237 238 list_del_init(&pfcp->list); 239 unregister_netdevice_queue_net(net, dev, head); 240 } 241 242 static void pfcp_dellink(struct net_device *dev, struct list_head *head) 243 { 244 struct pfcp_dev *pfcp = netdev_priv(dev); 245 struct pfcp_net *pn; 246 247 pn = net_generic(pfcp->net, pfcp_net_id); 248 249 mutex_lock(&pn->lock); 250 if (!list_empty(&pfcp->list)) 251 __pfcp_dellink(dev_net(dev), dev, head); 252 mutex_unlock(&pn->lock); 253 } 254 255 static struct rtnl_link_ops pfcp_link_ops __read_mostly = { 256 .kind = "pfcp", 257 .priv_size = sizeof(struct pfcp_dev), 258 .setup = pfcp_link_setup, 259 .newlink = pfcp_newlink, 260 .dellink = pfcp_dellink, 261 }; 262 263 static int __net_init pfcp_net_init(struct net *net) 264 { 265 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 266 267 INIT_LIST_HEAD(&pn->pfcp_dev_list); 268 mutex_init(&pn->lock); 269 270 return 0; 271 } 272 273 static void __net_exit pfcp_net_exit_rtnl(struct net *net, 274 struct list_head *dev_to_kill) 275 { 276 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 277 struct pfcp_dev *pfcp, *pfcp_next; 278 279 mutex_lock(&pn->lock); 280 281 list_for_each_entry_safe(pfcp, pfcp_next, &pn->pfcp_dev_list, list) 282 __pfcp_dellink(net, pfcp->dev, dev_to_kill); 283 284 mutex_unlock(&pn->lock); 285 } 286 287 static struct pernet_operations pfcp_net_ops = { 288 .init = pfcp_net_init, 289 .exit_rtnl = pfcp_net_exit_rtnl, 290 .id = &pfcp_net_id, 291 .size = sizeof(struct pfcp_net), 292 }; 293 294 static int __init pfcp_init(void) 295 { 296 int err; 297 298 err = register_pernet_subsys(&pfcp_net_ops); 299 if (err) 300 goto exit_err; 301 302 err = rtnl_link_register(&pfcp_link_ops); 303 if (err) 304 goto exit_unregister_subsys; 305 return 0; 306 307 exit_unregister_subsys: 308 unregister_pernet_subsys(&pfcp_net_ops); 309 exit_err: 310 pr_err("loading PFCP module failed: err %d\n", err); 311 return err; 312 } 313 late_initcall(pfcp_init); 314 315 static void __exit pfcp_exit(void) 316 { 317 rtnl_link_unregister(&pfcp_link_ops); 318 unregister_pernet_subsys(&pfcp_net_ops); 319 320 pr_info("PFCP module unloaded\n"); 321 } 322 module_exit(pfcp_exit); 323 324 MODULE_LICENSE("GPL"); 325 MODULE_AUTHOR("Wojciech Drewek <wojciech.drewek@intel.com>"); 326 MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic"); 327 MODULE_ALIAS_RTNL_LINK("pfcp"); 328