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 struct sk_buff *hsr_fill_tag(struct sk_buff *skb, 124 struct hsr_frame_info *frame, 125 struct hsr_port *port, u8 proto_version) 126 { 127 struct hsr_ethhdr *hsr_ethhdr; 128 int lane_id; 129 int lsdu_size; 130 131 /* pad to minimum packet size which is 60 + 6 (HSR tag) */ 132 if (skb_put_padto(skb, ETH_ZLEN + HSR_HLEN)) 133 return NULL; 134 135 if (port->type == HSR_PT_SLAVE_A) 136 lane_id = 0; 137 else 138 lane_id = 1; 139 140 lsdu_size = skb->len - 14; 141 if (frame->is_vlan) 142 lsdu_size -= 4; 143 144 hsr_ethhdr = (struct hsr_ethhdr *)skb_mac_header(skb); 145 146 set_hsr_tag_path(&hsr_ethhdr->hsr_tag, lane_id); 147 set_hsr_tag_LSDU_size(&hsr_ethhdr->hsr_tag, lsdu_size); 148 hsr_ethhdr->hsr_tag.sequence_nr = htons(frame->sequence_nr); 149 hsr_ethhdr->hsr_tag.encap_proto = hsr_ethhdr->ethhdr.h_proto; 150 hsr_ethhdr->ethhdr.h_proto = htons(proto_version ? 151 ETH_P_HSR : ETH_P_PRP); 152 153 return skb; 154 } 155 156 static struct sk_buff *create_tagged_skb(struct sk_buff *skb_o, 157 struct hsr_frame_info *frame, 158 struct hsr_port *port) 159 { 160 int movelen; 161 unsigned char *dst, *src; 162 struct sk_buff *skb; 163 164 /* Create the new skb with enough headroom to fit the HSR tag */ 165 skb = __pskb_copy(skb_o, skb_headroom(skb_o) + HSR_HLEN, GFP_ATOMIC); 166 if (!skb) 167 return NULL; 168 skb_reset_mac_header(skb); 169 170 if (skb->ip_summed == CHECKSUM_PARTIAL) 171 skb->csum_start += HSR_HLEN; 172 173 movelen = ETH_HLEN; 174 if (frame->is_vlan) 175 movelen += VLAN_HLEN; 176 177 src = skb_mac_header(skb); 178 dst = skb_push(skb, HSR_HLEN); 179 memmove(dst, src, movelen); 180 skb_reset_mac_header(skb); 181 182 /* skb_put_padto free skb on error and hsr_fill_tag returns NULL in 183 * that case 184 */ 185 return hsr_fill_tag(skb, frame, port, port->hsr->prot_version); 186 } 187 188 /* If the original frame was an HSR tagged frame, just clone it to be sent 189 * unchanged. Otherwise, create a private frame especially tagged for 'port'. 190 */ 191 static struct sk_buff *frame_get_tagged_skb(struct hsr_frame_info *frame, 192 struct hsr_port *port) 193 { 194 if (frame->skb_hsr) 195 return skb_clone(frame->skb_hsr, GFP_ATOMIC); 196 197 if (port->type != HSR_PT_SLAVE_A && port->type != HSR_PT_SLAVE_B) { 198 WARN_ONCE(1, "HSR: Bug: trying to create a tagged frame for a non-ring port"); 199 return NULL; 200 } 201 202 return create_tagged_skb(frame->skb_std, frame, port); 203 } 204 205 static void hsr_deliver_master(struct sk_buff *skb, struct net_device *dev, 206 struct hsr_node *node_src) 207 { 208 bool was_multicast_frame; 209 int res; 210 211 was_multicast_frame = (skb->pkt_type == PACKET_MULTICAST); 212 hsr_addr_subst_source(node_src, skb); 213 skb_pull(skb, ETH_HLEN); 214 res = netif_rx(skb); 215 if (res == NET_RX_DROP) { 216 dev->stats.rx_dropped++; 217 } else { 218 dev->stats.rx_packets++; 219 dev->stats.rx_bytes += skb->len; 220 if (was_multicast_frame) 221 dev->stats.multicast++; 222 } 223 } 224 225 static int hsr_xmit(struct sk_buff *skb, struct hsr_port *port, 226 struct hsr_frame_info *frame) 227 { 228 if (frame->port_rcv->type == HSR_PT_MASTER) { 229 hsr_addr_subst_dest(frame->node_src, skb, port); 230 231 /* Address substitution (IEC62439-3 pp 26, 50): replace mac 232 * address of outgoing frame with that of the outgoing slave's. 233 */ 234 ether_addr_copy(eth_hdr(skb)->h_source, port->dev->dev_addr); 235 } 236 return dev_queue_xmit(skb); 237 } 238 239 /* Forward the frame through all devices except: 240 * - Back through the receiving device 241 * - If it's a HSR frame: through a device where it has passed before 242 * - To the local HSR master only if the frame is directly addressed to it, or 243 * a non-supervision multicast or broadcast frame. 244 * 245 * HSR slave devices should insert a HSR tag into the frame, or forward the 246 * frame unchanged if it's already tagged. Interlink devices should strip HSR 247 * tags if they're of the non-HSR type (but only after duplicate discard). The 248 * master device always strips HSR tags. 249 */ 250 static void hsr_forward_do(struct hsr_frame_info *frame) 251 { 252 struct hsr_port *port; 253 struct sk_buff *skb; 254 255 hsr_for_each_port(frame->port_rcv->hsr, port) { 256 /* Don't send frame back the way it came */ 257 if (port == frame->port_rcv) 258 continue; 259 260 /* Don't deliver locally unless we should */ 261 if (port->type == HSR_PT_MASTER && !frame->is_local_dest) 262 continue; 263 264 /* Deliver frames directly addressed to us to master only */ 265 if (port->type != HSR_PT_MASTER && frame->is_local_exclusive) 266 continue; 267 268 /* Don't send frame over port where it has been sent before */ 269 if (hsr_register_frame_out(port, frame->node_src, 270 frame->sequence_nr)) 271 continue; 272 273 if (frame->is_supervision && port->type == HSR_PT_MASTER) { 274 hsr_handle_sup_frame(frame->skb_hsr, 275 frame->node_src, 276 frame->port_rcv); 277 continue; 278 } 279 280 if (port->type != HSR_PT_MASTER) 281 skb = frame_get_tagged_skb(frame, port); 282 else 283 skb = frame_get_stripped_skb(frame, port); 284 if (!skb) { 285 /* FIXME: Record the dropped frame? */ 286 continue; 287 } 288 289 skb->dev = port->dev; 290 if (port->type == HSR_PT_MASTER) 291 hsr_deliver_master(skb, port->dev, frame->node_src); 292 else 293 hsr_xmit(skb, port, frame); 294 } 295 } 296 297 static void check_local_dest(struct hsr_priv *hsr, struct sk_buff *skb, 298 struct hsr_frame_info *frame) 299 { 300 if (hsr_addr_is_self(hsr, eth_hdr(skb)->h_dest)) { 301 frame->is_local_exclusive = true; 302 skb->pkt_type = PACKET_HOST; 303 } else { 304 frame->is_local_exclusive = false; 305 } 306 307 if (skb->pkt_type == PACKET_HOST || 308 skb->pkt_type == PACKET_MULTICAST || 309 skb->pkt_type == PACKET_BROADCAST) { 310 frame->is_local_dest = true; 311 } else { 312 frame->is_local_dest = false; 313 } 314 } 315 316 static int hsr_fill_frame_info(struct hsr_frame_info *frame, 317 struct sk_buff *skb, struct hsr_port *port) 318 { 319 struct ethhdr *ethhdr; 320 unsigned long irqflags; 321 322 frame->is_supervision = is_supervision_frame(port->hsr, skb); 323 frame->node_src = hsr_get_node(port, skb, frame->is_supervision); 324 if (!frame->node_src) 325 return -1; /* Unknown node and !is_supervision, or no mem */ 326 327 ethhdr = (struct ethhdr *)skb_mac_header(skb); 328 frame->is_vlan = false; 329 if (ethhdr->h_proto == htons(ETH_P_8021Q)) { 330 frame->is_vlan = true; 331 /* FIXME: */ 332 netdev_warn_once(skb->dev, "VLAN not yet supported"); 333 } 334 if (ethhdr->h_proto == htons(ETH_P_PRP) || 335 ethhdr->h_proto == htons(ETH_P_HSR)) { 336 frame->skb_std = NULL; 337 frame->skb_hsr = skb; 338 frame->sequence_nr = hsr_get_skb_sequence_nr(skb); 339 } else { 340 frame->skb_std = skb; 341 frame->skb_hsr = NULL; 342 /* Sequence nr for the master node */ 343 spin_lock_irqsave(&port->hsr->seqnr_lock, irqflags); 344 frame->sequence_nr = port->hsr->sequence_nr; 345 port->hsr->sequence_nr++; 346 spin_unlock_irqrestore(&port->hsr->seqnr_lock, irqflags); 347 } 348 349 frame->port_rcv = port; 350 check_local_dest(port->hsr, skb, frame); 351 352 return 0; 353 } 354 355 /* Must be called holding rcu read lock (because of the port parameter) */ 356 void hsr_forward_skb(struct sk_buff *skb, struct hsr_port *port) 357 { 358 struct hsr_frame_info frame; 359 360 if (skb_mac_header(skb) != skb->data) { 361 WARN_ONCE(1, "%s:%d: Malformed frame (port_src %s)\n", 362 __FILE__, __LINE__, port->dev->name); 363 goto out_drop; 364 } 365 366 if (hsr_fill_frame_info(&frame, skb, port) < 0) 367 goto out_drop; 368 hsr_register_frame_in(frame.node_src, port, frame.sequence_nr); 369 hsr_forward_do(&frame); 370 /* Gets called for ingress frames as well as egress from master port. 371 * So check and increment stats for master port only here. 372 */ 373 if (port->type == HSR_PT_MASTER) { 374 port->dev->stats.tx_packets++; 375 port->dev->stats.tx_bytes += skb->len; 376 } 377 378 if (frame.skb_hsr) 379 kfree_skb(frame.skb_hsr); 380 if (frame.skb_std) 381 kfree_skb(frame.skb_std); 382 return; 383 384 out_drop: 385 port->dev->stats.tx_dropped++; 386 kfree_skb(skb); 387 } 388