1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright 2011-2014 Autronica Fire and Security AS 3 * 4 * Author(s): 5 * 2011-2014 Arvid Brodin, arvid.brodin@alten.se 6 */ 7 8 #include "hsr_forward.h" 9 #include <linux/types.h> 10 #include <linux/skbuff.h> 11 #include <linux/etherdevice.h> 12 #include <linux/if_vlan.h> 13 #include "hsr_main.h" 14 #include "hsr_framereg.h" 15 16 struct hsr_node; 17 18 struct hsr_frame_info { 19 struct sk_buff *skb_std; 20 struct sk_buff *skb_hsr; 21 struct hsr_port *port_rcv; 22 struct hsr_node *node_src; 23 u16 sequence_nr; 24 bool is_supervision; 25 bool is_vlan; 26 bool is_local_dest; 27 bool is_local_exclusive; 28 }; 29 30 /* The uses I can see for these HSR supervision frames are: 31 * 1) Use the frames that are sent after node initialization ("HSR_TLV.Type = 32 * 22") to reset any sequence_nr counters belonging to that node. Useful if 33 * the other node's counter has been reset for some reason. 34 * -- 35 * Or not - resetting the counter and bridging the frame would create a 36 * loop, unfortunately. 37 * 38 * 2) Use the LifeCheck frames to detect ring breaks. I.e. if no LifeCheck 39 * frame is received from a particular node, we know something is wrong. 40 * We just register these (as with normal frames) and throw them away. 41 * 42 * 3) Allow different MAC addresses for the two slave interfaces, using the 43 * MacAddressA field. 44 */ 45 static bool is_supervision_frame(struct hsr_priv *hsr, struct sk_buff *skb) 46 { 47 struct ethhdr *eth_hdr; 48 struct hsr_sup_tag *hsr_sup_tag; 49 struct hsrv1_ethhdr_sp *hsr_V1_hdr; 50 51 WARN_ON_ONCE(!skb_mac_header_was_set(skb)); 52 eth_hdr = (struct ethhdr *)skb_mac_header(skb); 53 54 /* Correct addr? */ 55 if (!ether_addr_equal(eth_hdr->h_dest, 56 hsr->sup_multicast_addr)) 57 return false; 58 59 /* Correct ether type?. */ 60 if (!(eth_hdr->h_proto == htons(ETH_P_PRP) || 61 eth_hdr->h_proto == htons(ETH_P_HSR))) 62 return false; 63 64 /* Get the supervision header from correct location. */ 65 if (eth_hdr->h_proto == htons(ETH_P_HSR)) { /* Okay HSRv1. */ 66 hsr_V1_hdr = (struct hsrv1_ethhdr_sp *)skb_mac_header(skb); 67 if (hsr_V1_hdr->hsr.encap_proto != htons(ETH_P_PRP)) 68 return false; 69 70 hsr_sup_tag = &hsr_V1_hdr->hsr_sup; 71 } else { 72 hsr_sup_tag = 73 &((struct hsrv0_ethhdr_sp *)skb_mac_header(skb))->hsr_sup; 74 } 75 76 if (hsr_sup_tag->HSR_TLV_type != HSR_TLV_ANNOUNCE && 77 hsr_sup_tag->HSR_TLV_type != HSR_TLV_LIFE_CHECK) 78 return false; 79 if (hsr_sup_tag->HSR_TLV_length != 12 && 80 hsr_sup_tag->HSR_TLV_length != sizeof(struct hsr_sup_payload)) 81 return false; 82 83 return true; 84 } 85 86 static struct sk_buff *create_stripped_skb(struct sk_buff *skb_in, 87 struct hsr_frame_info *frame) 88 { 89 struct sk_buff *skb; 90 int copylen; 91 unsigned char *dst, *src; 92 93 skb_pull(skb_in, HSR_HLEN); 94 skb = __pskb_copy(skb_in, skb_headroom(skb_in) - HSR_HLEN, GFP_ATOMIC); 95 skb_push(skb_in, HSR_HLEN); 96 if (!skb) 97 return NULL; 98 99 skb_reset_mac_header(skb); 100 101 if (skb->ip_summed == CHECKSUM_PARTIAL) 102 skb->csum_start -= HSR_HLEN; 103 104 copylen = 2 * ETH_ALEN; 105 if (frame->is_vlan) 106 copylen += VLAN_HLEN; 107 src = skb_mac_header(skb_in); 108 dst = skb_mac_header(skb); 109 memcpy(dst, src, copylen); 110 111 skb->protocol = eth_hdr(skb)->h_proto; 112 return skb; 113 } 114 115 static struct sk_buff *frame_get_stripped_skb(struct hsr_frame_info *frame, 116 struct hsr_port *port) 117 { 118 if (!frame->skb_std) 119 frame->skb_std = create_stripped_skb(frame->skb_hsr, frame); 120 return skb_clone(frame->skb_std, GFP_ATOMIC); 121 } 122 123 static void hsr_fill_tag(struct sk_buff *skb, struct hsr_frame_info *frame, 124 struct hsr_port *port, u8 proto_version) 125 { 126 struct hsr_ethhdr *hsr_ethhdr; 127 int lane_id; 128 int lsdu_size; 129 130 if (port->type == HSR_PT_SLAVE_A) 131 lane_id = 0; 132 else 133 lane_id = 1; 134 135 lsdu_size = skb->len - 14; 136 if (frame->is_vlan) 137 lsdu_size -= 4; 138 139 hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb); 140 141 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id); 142 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size); 143 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr); 144 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto; 145 hsr_ethhdr->ethhdr.h_proto = htons(proto_version ? 146 ETH_P_HSR : ETH_P_PRP); 147 } 148 149 static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o, 150 struct hsr_frame_info *frame, 151 struct hsr_port *port) 152 { 153 int movelen; 154 unsigned char *dst, *src; 155 struct sk_buff *skb; 156 157 /* Create the new skb with enough headroom to fit the HSR tag */ 158 skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC); 159 if (!skb) 160 return NULL; 161 skb_reset_mac_header(skb); 162 163 if (skb->ip_summed == CHECKSUM_PARTIAL) 164 skb->csum_start += HSR_HLEN; 165 166 movelen = ETH_HLEN; 167 if (frame->is_vlan) 168 movelen += VLAN_HLEN; 169 170 src = skb_mac_header(skb); 171 dst = skb_push(skb, HSR_HLEN); 172 memmove(dst, src, movelen); 173 skb_reset_mac_header(skb); 174 175 hsr_fill_tag(skb, frame, port, port->hsr->prot_version); 176 177 return skb; 178 } 179 180 /* If the original frame was an HSR tagged frame, just clone it to be sent 181 * unchanged. Otherwise, create a private frame especially tagged for 'port'. 182 */ 183 static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame, 184 struct hsr_port *port) 185 { 186 if (frame->skb_hsr) 187 return skb_clone(frame->skb_hsr, GFP_ATOMIC); 188 189 if (port->type != HSR_PT_SLAVE_A && port->type != HSR_PT_SLAVE_B) { 190 WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port"); 191 return NULL; 192 } 193 194 return create_tagged_skb(frame->skb_std, frame, port); 195 } 196 197 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, 198 struct hsr_node *node_src) 199 { 200 bool was_multicast_frame; 201 int res; 202 203 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); 204 hsr_addr_subst_source(node_src, skb); 205 skb_pull(skb, ETH_HLEN); 206 res = netif_rx(skb); 207 if (res == NET_RX_DROP) { 208 dev->stats.rx_dropped++; 209 } else { 210 dev->stats.rx_packets++; 211 dev->stats.rx_bytes += skb->len; 212 if (was_multicast_frame) 213 dev->stats.multicast++; 214 } 215 } 216 217 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, 218 struct hsr_frame_info *frame) 219 { 220 if (frame->port_rcv->type == HSR_PT_MASTER) { 221 hsr_addr_subst_dest(frame->node_src, skb, port); 222 223 /* Address substitution (IEC62439-3 pp 26, 50): replace mac 224 * address of outgoing frame with that of the outgoing slave's. 225 */ 226 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); 227 } 228 return dev_queue_xmit(skb); 229 } 230 231 /* Forward the frame through all devices except: 232 * - Back through the receiving device 233 * - If it's a HSR frame: through a device where it has passed before 234 * - To the local HSR master only if the frame is directly addressed to it, or 235 * a non-supervision multicast or broadcast frame. 236 * 237 * HSR slave devices should insert a HSR tag into the frame, or forward the 238 * frame unchanged if it's already tagged. Interlink devices should strip HSR 239 * tags if they're of the non-HSR type (but only after duplicate discard). The 240 * master device always strips HSR tags. 241 */ 242 static void hsr_forward_do(struct hsr_frame_info *frame) 243 { 244 struct hsr_port *port; 245 struct sk_buff *skb; 246 247 hsr_for_each_port(frame->port_rcv->hsr, port) { 248 /* Don't send frame back the way it came */ 249 if (port == frame->port_rcv) 250 continue; 251 252 /* Don't deliver locally unless we should */ 253 if (port->type == HSR_PT_MASTER && !frame->is_local_dest) 254 continue; 255 256 /* Deliver frames directly addressed to us to master only */ 257 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive) 258 continue; 259 260 /* Don't send frame over port where it has been sent before */ 261 if (hsr_register_frame_out(port, frame->node_src, 262 frame->sequence_nr)) 263 continue; 264 265 if (frame->is_supervision && port->type == HSR_PT_MASTER) { 266 hsr_handle_sup_frame(frame->skb_hsr, 267 frame->node_src, 268 frame->port_rcv); 269 continue; 270 } 271 272 if (port->type != HSR_PT_MASTER) 273 skb = frame_get_tagged_skb(frame, port); 274 else 275 skb = frame_get_stripped_skb(frame, port); 276 if (!skb) { 277 /* FIXME: Record the dropped frame? */ 278 continue; 279 } 280 281 skb->dev = port->dev; 282 if (port->type == HSR_PT_MASTER) 283 hsr_deliver_master(skb, port->dev, frame->node_src); 284 else 285 hsr_xmit(skb, port, frame); 286 } 287 } 288 289 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, 290 struct hsr_frame_info *frame) 291 { 292 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { 293 frame->is_local_exclusive = true; 294 skb->pkt_type = PACKET_HOST; 295 } else { 296 frame->is_local_exclusive = false; 297 } 298 299 if (skb->pkt_type == PACKET_HOST || 300 skb->pkt_type == PACKET_MULTICAST || 301 skb->pkt_type == PACKET_BROADCAST) { 302 frame->is_local_dest = true; 303 } else { 304 frame->is_local_dest = false; 305 } 306 } 307 308 static int hsr_fill_frame_info(struct hsr_frame_info *frame, 309 struct sk_buff *skb, struct hsr_port *port) 310 { 311 struct ethhdr *ethhdr; 312 unsigned long irqflags; 313 314 frame->is_supervision = is_supervision_frame(port->hsr, skb); 315 frame->node_src = hsr_get_node(port, skb, frame->is_supervision); 316 if (!frame->node_src) 317 return -1; /* Unknown node and !is_supervision, or no mem */ 318 319 ethhdr = (struct ethhdr *)skb_mac_header(skb); 320 frame->is_vlan = false; 321 if (ethhdr->h_proto == htons(ETH_P_8021Q)) { 322 frame->is_vlan = true; 323 /* FIXME: */ 324 netdev_warn_once(skb->dev, "VLAN not yet supported"); 325 } 326 if (ethhdr->h_proto == htons(ETH_P_PRP) || 327 ethhdr->h_proto == htons(ETH_P_HSR)) { 328 frame->skb_std = NULL; 329 frame->skb_hsr = skb; 330 frame->sequence_nr = hsr_get_skb_sequence_nr(skb); 331 } else { 332 frame->skb_std = skb; 333 frame->skb_hsr = NULL; 334 /* Sequence nr for the master node */ 335 spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags); 336 frame->sequence_nr = port->hsr->sequence_nr; 337 port->hsr->sequence_nr++; 338 spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags); 339 } 340 341 frame->port_rcv = port; 342 check_local_dest(port->hsr, skb, frame); 343 344 return 0; 345 } 346 347 /* Must be called holding rcu read lock (because of the port parameter) */ 348 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) 349 { 350 struct hsr_frame_info frame; 351 352 if (skb_mac_header(skb) != skb->data) { 353 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n", 354 __FILE__, __LINE__, port->dev->name); 355 goto out_drop; 356 } 357 358 if (hsr_fill_frame_info(&frame, skb, port) < 0) 359 goto out_drop; 360 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); 361 hsr_forward_do(&frame); 362 /* Gets called for ingress frames as well as egress from master port. 363 * So check and increment stats for master port only here. 364 */ 365 if (port->type == HSR_PT_MASTER) { 366 port->dev->stats.tx_packets++; 367 port->dev->stats.tx_bytes += skb->len; 368 } 369 370 if (frame.skb_hsr) 371 kfree_skb(frame.skb_hsr); 372 if (frame.skb_std) 373 kfree_skb(frame.skb_std); 374 return; 375 376 out_drop: 377 port->dev->stats.tx_dropped++; 378 kfree_skb(skb); 379 } 380