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 socket *sock; 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 }; 33 34 static void 35 pfcp_session_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 36 struct pfcp_metadata *md) 37 { 38 struct pfcphdr_session *unparsed = pfcp_hdr_session(skb); 39 40 md->seid = unparsed->seid; 41 md->type = PFCP_TYPE_SESSION; 42 } 43 44 static void 45 pfcp_node_recv(struct pfcp_dev *pfcp, struct sk_buff *skb, 46 struct pfcp_metadata *md) 47 { 48 md->type = PFCP_TYPE_NODE; 49 } 50 51 static int pfcp_encap_recv(struct sock *sk, struct sk_buff *skb) 52 { 53 IP_TUNNEL_DECLARE_FLAGS(flags) = { }; 54 struct metadata_dst *tun_dst; 55 struct pfcp_metadata *md; 56 struct pfcphdr *unparsed; 57 struct pfcp_dev *pfcp; 58 59 if (unlikely(!pskb_may_pull(skb, PFCP_HLEN))) 60 goto drop; 61 62 pfcp = rcu_dereference_sk_user_data(sk); 63 if (unlikely(!pfcp)) 64 goto drop; 65 66 unparsed = pfcp_hdr(skb); 67 68 ip_tunnel_flags_zero(flags); 69 tun_dst = udp_tun_rx_dst(skb, sk->sk_family, flags, 0, 70 sizeof(*md)); 71 if (unlikely(!tun_dst)) 72 goto drop; 73 74 md = ip_tunnel_info_opts(&tun_dst->u.tun_info); 75 if (unlikely(!md)) 76 goto drop; 77 78 if (unparsed->flags & PFCP_SEID_FLAG) 79 pfcp_session_recv(pfcp, skb, md); 80 else 81 pfcp_node_recv(pfcp, skb, md); 82 83 __set_bit(IP_TUNNEL_PFCP_OPT_BIT, tun_dst->u.tun_info.key.tun_flags); 84 tun_dst->u.tun_info.options_len = sizeof(*md); 85 86 if (unlikely(iptunnel_pull_header(skb, PFCP_HLEN, skb->protocol, 87 !net_eq(sock_net(sk), 88 dev_net(pfcp->dev))))) 89 goto drop; 90 91 skb_dst_set(skb, (struct dst_entry *)tun_dst); 92 93 skb_reset_network_header(skb); 94 skb_reset_mac_header(skb); 95 skb->dev = pfcp->dev; 96 97 gro_cells_receive(&pfcp->gro_cells, skb); 98 99 return 0; 100 drop: 101 kfree_skb(skb); 102 return 0; 103 } 104 105 static void pfcp_del_sock(struct pfcp_dev *pfcp) 106 { 107 udp_tunnel_sock_release(pfcp->sock); 108 pfcp->sock = NULL; 109 } 110 111 static void pfcp_dev_uninit(struct net_device *dev) 112 { 113 struct pfcp_dev *pfcp = netdev_priv(dev); 114 115 gro_cells_destroy(&pfcp->gro_cells); 116 pfcp_del_sock(pfcp); 117 } 118 119 static int pfcp_dev_init(struct net_device *dev) 120 { 121 struct pfcp_dev *pfcp = netdev_priv(dev); 122 123 pfcp->dev = dev; 124 125 return gro_cells_init(&pfcp->gro_cells, dev); 126 } 127 128 static const struct net_device_ops pfcp_netdev_ops = { 129 .ndo_init = pfcp_dev_init, 130 .ndo_uninit = pfcp_dev_uninit, 131 .ndo_get_stats64 = dev_get_tstats64, 132 }; 133 134 static const struct device_type pfcp_type = { 135 .name = "pfcp", 136 }; 137 138 static void pfcp_link_setup(struct net_device *dev) 139 { 140 dev->netdev_ops = &pfcp_netdev_ops; 141 dev->needs_free_netdev = true; 142 SET_NETDEV_DEVTYPE(dev, &pfcp_type); 143 144 dev->hard_header_len = 0; 145 dev->addr_len = 0; 146 147 dev->type = ARPHRD_NONE; 148 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 149 dev->priv_flags |= IFF_NO_QUEUE; 150 151 netif_keep_dst(dev); 152 } 153 154 static struct socket *pfcp_create_sock(struct pfcp_dev *pfcp) 155 { 156 struct udp_tunnel_sock_cfg tuncfg = {}; 157 struct udp_port_cfg udp_conf = { 158 .local_ip.s_addr = htonl(INADDR_ANY), 159 .family = AF_INET, 160 }; 161 struct net *net = pfcp->net; 162 struct socket *sock; 163 int err; 164 165 udp_conf.local_udp_port = htons(PFCP_PORT); 166 167 err = udp_sock_create(net, &udp_conf, &sock); 168 if (err) 169 return ERR_PTR(err); 170 171 tuncfg.sk_user_data = pfcp; 172 tuncfg.encap_rcv = pfcp_encap_recv; 173 tuncfg.encap_type = 1; 174 175 setup_udp_tunnel_sock(net, sock, &tuncfg); 176 177 return sock; 178 } 179 180 static int pfcp_add_sock(struct pfcp_dev *pfcp) 181 { 182 pfcp->sock = pfcp_create_sock(pfcp); 183 184 return PTR_ERR_OR_ZERO(pfcp->sock); 185 } 186 187 static int pfcp_newlink(struct net *net, struct net_device *dev, 188 struct nlattr *tb[], struct nlattr *data[], 189 struct netlink_ext_ack *extack) 190 { 191 struct pfcp_dev *pfcp = netdev_priv(dev); 192 struct pfcp_net *pn; 193 int err; 194 195 pfcp->net = net; 196 197 err = pfcp_add_sock(pfcp); 198 if (err) { 199 netdev_dbg(dev, "failed to add pfcp socket %d\n", err); 200 goto exit_err; 201 } 202 203 err = register_netdevice(dev); 204 if (err) { 205 netdev_dbg(dev, "failed to register pfcp netdev %d\n", err); 206 goto exit_del_pfcp_sock; 207 } 208 209 pn = net_generic(dev_net(dev), pfcp_net_id); 210 list_add_rcu(&pfcp->list, &pn->pfcp_dev_list); 211 212 netdev_dbg(dev, "registered new PFCP interface\n"); 213 214 return 0; 215 216 exit_del_pfcp_sock: 217 pfcp_del_sock(pfcp); 218 exit_err: 219 pfcp->net = NULL; 220 return err; 221 } 222 223 static void pfcp_dellink(struct net_device *dev, struct list_head *head) 224 { 225 struct pfcp_dev *pfcp = netdev_priv(dev); 226 227 list_del_rcu(&pfcp->list); 228 unregister_netdevice_queue(dev, head); 229 } 230 231 static struct rtnl_link_ops pfcp_link_ops __read_mostly = { 232 .kind = "pfcp", 233 .priv_size = sizeof(struct pfcp_dev), 234 .setup = pfcp_link_setup, 235 .newlink = pfcp_newlink, 236 .dellink = pfcp_dellink, 237 }; 238 239 static int __net_init pfcp_net_init(struct net *net) 240 { 241 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 242 243 INIT_LIST_HEAD(&pn->pfcp_dev_list); 244 return 0; 245 } 246 247 static void __net_exit pfcp_net_exit(struct net *net) 248 { 249 struct pfcp_net *pn = net_generic(net, pfcp_net_id); 250 struct pfcp_dev *pfcp; 251 LIST_HEAD(list); 252 253 rtnl_lock(); 254 list_for_each_entry(pfcp, &pn->pfcp_dev_list, list) 255 pfcp_dellink(pfcp->dev, &list); 256 257 unregister_netdevice_many(&list); 258 rtnl_unlock(); 259 } 260 261 static struct pernet_operations pfcp_net_ops = { 262 .init = pfcp_net_init, 263 .exit = pfcp_net_exit, 264 .id = &pfcp_net_id, 265 .size = sizeof(struct pfcp_net), 266 }; 267 268 static int __init pfcp_init(void) 269 { 270 int err; 271 272 err = register_pernet_subsys(&pfcp_net_ops); 273 if (err) 274 goto exit_err; 275 276 err = rtnl_link_register(&pfcp_link_ops); 277 if (err) 278 goto exit_unregister_subsys; 279 return 0; 280 281 exit_unregister_subsys: 282 unregister_pernet_subsys(&pfcp_net_ops); 283 exit_err: 284 pr_err("loading PFCP module failed: err %d\n", err); 285 return err; 286 } 287 late_initcall(pfcp_init); 288 289 static void __exit pfcp_exit(void) 290 { 291 rtnl_link_unregister(&pfcp_link_ops); 292 unregister_pernet_subsys(&pfcp_net_ops); 293 294 pr_info("PFCP module unloaded\n"); 295 } 296 module_exit(pfcp_exit); 297 298 MODULE_LICENSE("GPL"); 299 MODULE_AUTHOR("Wojciech Drewek <wojciech.drewek@intel.com>"); 300 MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic"); 301 MODULE_ALIAS_RTNL_LINK("pfcp"); 302