1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com> 3 * 4 * This module is not a complete tagger implementation. It only provides 5 * primitives for taggers that rely on 802.1Q VLAN tags to use. The 6 * dsa_8021q_netdev_ops is registered for API compliance and not used 7 * directly by callers. 8 */ 9 #include <linux/if_vlan.h> 10 #include <linux/dsa/8021q.h> 11 12 #include "dsa_priv.h" 13 14 /* Binary structure of the fake 12-bit VID field (when the TPID is 15 * ETH_P_DSA_8021Q): 16 * 17 * | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 18 * +-----------+-----+-----------------+-----------+-----------------------+ 19 * | DIR | VBID| SWITCH_ID | VBID | PORT | 20 * +-----------+-----+-----------------+-----------+-----------------------+ 21 * 22 * DIR - VID[11:10]: 23 * Direction flags. 24 * * 1 (0b01) for RX VLAN, 25 * * 2 (0b10) for TX VLAN. 26 * These values make the special VIDs of 0, 1 and 4095 to be left 27 * unused by this coding scheme. 28 * 29 * SWITCH_ID - VID[8:6]: 30 * Index of switch within DSA tree. Must be between 0 and 7. 31 * 32 * VBID - { VID[9], VID[5:4] }: 33 * Virtual bridge ID. If between 1 and 7, packet targets the broadcast 34 * domain of a bridge. If transmitted as zero, packet targets a single 35 * port. Field only valid on transmit, must be ignored on receive. 36 * 37 * PORT - VID[3:0]: 38 * Index of switch port. Must be between 0 and 15. 39 */ 40 41 #define DSA_8021Q_DIR_SHIFT 10 42 #define DSA_8021Q_DIR_MASK GENMASK(11, 10) 43 #define DSA_8021Q_DIR(x) (((x) << DSA_8021Q_DIR_SHIFT) & \ 44 DSA_8021Q_DIR_MASK) 45 #define DSA_8021Q_DIR_RX DSA_8021Q_DIR(1) 46 #define DSA_8021Q_DIR_TX DSA_8021Q_DIR(2) 47 48 #define DSA_8021Q_SWITCH_ID_SHIFT 6 49 #define DSA_8021Q_SWITCH_ID_MASK GENMASK(8, 6) 50 #define DSA_8021Q_SWITCH_ID(x) (((x) << DSA_8021Q_SWITCH_ID_SHIFT) & \ 51 DSA_8021Q_SWITCH_ID_MASK) 52 53 #define DSA_8021Q_VBID_HI_SHIFT 9 54 #define DSA_8021Q_VBID_HI_MASK GENMASK(9, 9) 55 #define DSA_8021Q_VBID_LO_SHIFT 4 56 #define DSA_8021Q_VBID_LO_MASK GENMASK(5, 4) 57 #define DSA_8021Q_VBID_HI(x) (((x) & GENMASK(2, 2)) >> 2) 58 #define DSA_8021Q_VBID_LO(x) ((x) & GENMASK(1, 0)) 59 #define DSA_8021Q_VBID(x) \ 60 (((DSA_8021Q_VBID_LO(x) << DSA_8021Q_VBID_LO_SHIFT) & \ 61 DSA_8021Q_VBID_LO_MASK) | \ 62 ((DSA_8021Q_VBID_HI(x) << DSA_8021Q_VBID_HI_SHIFT) & \ 63 DSA_8021Q_VBID_HI_MASK)) 64 65 #define DSA_8021Q_PORT_SHIFT 0 66 #define DSA_8021Q_PORT_MASK GENMASK(3, 0) 67 #define DSA_8021Q_PORT(x) (((x) << DSA_8021Q_PORT_SHIFT) & \ 68 DSA_8021Q_PORT_MASK) 69 70 u16 dsa_8021q_bridge_tx_fwd_offload_vid(int bridge_num) 71 { 72 /* The VBID value of 0 is reserved for precise TX */ 73 return DSA_8021Q_DIR_TX | DSA_8021Q_VBID(bridge_num + 1); 74 } 75 EXPORT_SYMBOL_GPL(dsa_8021q_bridge_tx_fwd_offload_vid); 76 77 /* Returns the VID to be inserted into the frame from xmit for switch steering 78 * instructions on egress. Encodes switch ID and port ID. 79 */ 80 u16 dsa_tag_8021q_tx_vid(const struct dsa_port *dp) 81 { 82 return DSA_8021Q_DIR_TX | DSA_8021Q_SWITCH_ID(dp->ds->index) | 83 DSA_8021Q_PORT(dp->index); 84 } 85 EXPORT_SYMBOL_GPL(dsa_tag_8021q_tx_vid); 86 87 /* Returns the VID that will be installed as pvid for this switch port, sent as 88 * tagged egress towards the CPU port and decoded by the rcv function. 89 */ 90 u16 dsa_tag_8021q_rx_vid(const struct dsa_port *dp) 91 { 92 return DSA_8021Q_DIR_RX | DSA_8021Q_SWITCH_ID(dp->ds->index) | 93 DSA_8021Q_PORT(dp->index); 94 } 95 EXPORT_SYMBOL_GPL(dsa_tag_8021q_rx_vid); 96 97 /* Returns the decoded switch ID from the RX VID. */ 98 int dsa_8021q_rx_switch_id(u16 vid) 99 { 100 return (vid & DSA_8021Q_SWITCH_ID_MASK) >> DSA_8021Q_SWITCH_ID_SHIFT; 101 } 102 EXPORT_SYMBOL_GPL(dsa_8021q_rx_switch_id); 103 104 /* Returns the decoded port ID from the RX VID. */ 105 int dsa_8021q_rx_source_port(u16 vid) 106 { 107 return (vid & DSA_8021Q_PORT_MASK) >> DSA_8021Q_PORT_SHIFT; 108 } 109 EXPORT_SYMBOL_GPL(dsa_8021q_rx_source_port); 110 111 bool vid_is_dsa_8021q_rxvlan(u16 vid) 112 { 113 return (vid & DSA_8021Q_DIR_MASK) == DSA_8021Q_DIR_RX; 114 } 115 EXPORT_SYMBOL_GPL(vid_is_dsa_8021q_rxvlan); 116 117 bool vid_is_dsa_8021q_txvlan(u16 vid) 118 { 119 return (vid & DSA_8021Q_DIR_MASK) == DSA_8021Q_DIR_TX; 120 } 121 EXPORT_SYMBOL_GPL(vid_is_dsa_8021q_txvlan); 122 123 bool vid_is_dsa_8021q(u16 vid) 124 { 125 return vid_is_dsa_8021q_rxvlan(vid) || vid_is_dsa_8021q_txvlan(vid); 126 } 127 EXPORT_SYMBOL_GPL(vid_is_dsa_8021q); 128 129 static struct dsa_tag_8021q_vlan * 130 dsa_tag_8021q_vlan_find(struct dsa_8021q_context *ctx, int port, u16 vid) 131 { 132 struct dsa_tag_8021q_vlan *v; 133 134 list_for_each_entry(v, &ctx->vlans, list) 135 if (v->vid == vid && v->port == port) 136 return v; 137 138 return NULL; 139 } 140 141 static int dsa_port_do_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid, 142 u16 flags) 143 { 144 struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx; 145 struct dsa_switch *ds = dp->ds; 146 struct dsa_tag_8021q_vlan *v; 147 int port = dp->index; 148 int err; 149 150 /* No need to bother with refcounting for user ports */ 151 if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) 152 return ds->ops->tag_8021q_vlan_add(ds, port, vid, flags); 153 154 v = dsa_tag_8021q_vlan_find(ctx, port, vid); 155 if (v) { 156 refcount_inc(&v->refcount); 157 return 0; 158 } 159 160 v = kzalloc(sizeof(*v), GFP_KERNEL); 161 if (!v) 162 return -ENOMEM; 163 164 err = ds->ops->tag_8021q_vlan_add(ds, port, vid, flags); 165 if (err) { 166 kfree(v); 167 return err; 168 } 169 170 v->vid = vid; 171 v->port = port; 172 refcount_set(&v->refcount, 1); 173 list_add_tail(&v->list, &ctx->vlans); 174 175 return 0; 176 } 177 178 static int dsa_port_do_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid) 179 { 180 struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx; 181 struct dsa_switch *ds = dp->ds; 182 struct dsa_tag_8021q_vlan *v; 183 int port = dp->index; 184 int err; 185 186 /* No need to bother with refcounting for user ports */ 187 if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))) 188 return ds->ops->tag_8021q_vlan_del(ds, port, vid); 189 190 v = dsa_tag_8021q_vlan_find(ctx, port, vid); 191 if (!v) 192 return -ENOENT; 193 194 if (!refcount_dec_and_test(&v->refcount)) 195 return 0; 196 197 err = ds->ops->tag_8021q_vlan_del(ds, port, vid); 198 if (err) { 199 refcount_inc(&v->refcount); 200 return err; 201 } 202 203 list_del(&v->list); 204 kfree(v); 205 206 return 0; 207 } 208 209 static bool 210 dsa_port_tag_8021q_vlan_match(struct dsa_port *dp, 211 struct dsa_notifier_tag_8021q_vlan_info *info) 212 { 213 struct dsa_switch *ds = dp->ds; 214 215 if (dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp)) 216 return true; 217 218 if (ds->dst->index == info->tree_index && ds->index == info->sw_index) 219 return dp->index == info->port; 220 221 return false; 222 } 223 224 int dsa_switch_tag_8021q_vlan_add(struct dsa_switch *ds, 225 struct dsa_notifier_tag_8021q_vlan_info *info) 226 { 227 struct dsa_port *dp; 228 int err; 229 230 /* Since we use dsa_broadcast(), there might be other switches in other 231 * trees which don't support tag_8021q, so don't return an error. 232 * Or they might even support tag_8021q but have not registered yet to 233 * use it (maybe they use another tagger currently). 234 */ 235 if (!ds->ops->tag_8021q_vlan_add || !ds->tag_8021q_ctx) 236 return 0; 237 238 dsa_switch_for_each_port(dp, ds) { 239 if (dsa_port_tag_8021q_vlan_match(dp, info)) { 240 u16 flags = 0; 241 242 if (dsa_port_is_user(dp)) 243 flags |= BRIDGE_VLAN_INFO_UNTAGGED; 244 245 if (vid_is_dsa_8021q_rxvlan(info->vid) && 246 dsa_8021q_rx_switch_id(info->vid) == ds->index && 247 dsa_8021q_rx_source_port(info->vid) == dp->index) 248 flags |= BRIDGE_VLAN_INFO_PVID; 249 250 err = dsa_port_do_tag_8021q_vlan_add(dp, info->vid, 251 flags); 252 if (err) 253 return err; 254 } 255 } 256 257 return 0; 258 } 259 260 int dsa_switch_tag_8021q_vlan_del(struct dsa_switch *ds, 261 struct dsa_notifier_tag_8021q_vlan_info *info) 262 { 263 struct dsa_port *dp; 264 int err; 265 266 if (!ds->ops->tag_8021q_vlan_del || !ds->tag_8021q_ctx) 267 return 0; 268 269 dsa_switch_for_each_port(dp, ds) { 270 if (dsa_port_tag_8021q_vlan_match(dp, info)) { 271 err = dsa_port_do_tag_8021q_vlan_del(dp, info->vid); 272 if (err) 273 return err; 274 } 275 } 276 277 return 0; 278 } 279 280 /* RX VLAN tagging (left) and TX VLAN tagging (right) setup shown for a single 281 * front-panel switch port (here swp0). 282 * 283 * Port identification through VLAN (802.1Q) tags has different requirements 284 * for it to work effectively: 285 * - On RX (ingress from network): each front-panel port must have a pvid 286 * that uniquely identifies it, and the egress of this pvid must be tagged 287 * towards the CPU port, so that software can recover the source port based 288 * on the VID in the frame. But this would only work for standalone ports; 289 * if bridged, this VLAN setup would break autonomous forwarding and would 290 * force all switched traffic to pass through the CPU. So we must also make 291 * the other front-panel ports members of this VID we're adding, albeit 292 * we're not making it their PVID (they'll still have their own). 293 * - On TX (ingress from CPU and towards network) we are faced with a problem. 294 * If we were to tag traffic (from within DSA) with the port's pvid, all 295 * would be well, assuming the switch ports were standalone. Frames would 296 * have no choice but to be directed towards the correct front-panel port. 297 * But because we also want the RX VLAN to not break bridging, then 298 * inevitably that means that we have to give them a choice (of what 299 * front-panel port to go out on), and therefore we cannot steer traffic 300 * based on the RX VID. So what we do is simply install one more VID on the 301 * front-panel and CPU ports, and profit off of the fact that steering will 302 * work just by virtue of the fact that there is only one other port that's 303 * a member of the VID we're tagging the traffic with - the desired one. 304 * 305 * So at the end, each front-panel port will have one RX VID (also the PVID), 306 * the RX VID of all other front-panel ports that are in the same bridge, and 307 * one TX VID. Whereas the CPU port will have the RX and TX VIDs of all 308 * front-panel ports, and on top of that, is also tagged-input and 309 * tagged-output (VLAN trunk). 310 * 311 * CPU port CPU port 312 * +-------------+-----+-------------+ +-------------+-----+-------------+ 313 * | RX VID | | | | TX VID | | | 314 * | of swp0 | | | | of swp0 | | | 315 * | +-----+ | | +-----+ | 316 * | ^ T | | | Tagged | 317 * | | | | | ingress | 318 * | +-------+---+---+-------+ | | +-----------+ | 319 * | | | | | | | | Untagged | 320 * | | U v U v U v | | v egress | 321 * | +-----+ +-----+ +-----+ +-----+ | | +-----+ +-----+ +-----+ +-----+ | 322 * | | | | | | | | | | | | | | | | | | | | 323 * | |PVID | | | | | | | | | | | | | | | | | | 324 * +-+-----+-+-----+-+-----+-+-----+-+ +-+-----+-+-----+-+-----+-+-----+-+ 325 * swp0 swp1 swp2 swp3 swp0 swp1 swp2 swp3 326 */ 327 static bool 328 dsa_port_tag_8021q_bridge_match(struct dsa_port *dp, 329 struct dsa_notifier_bridge_info *info) 330 { 331 /* Don't match on self */ 332 if (dp->ds->dst->index == info->tree_index && 333 dp->ds->index == info->sw_index && 334 dp->index == info->port) 335 return false; 336 337 if (dsa_port_is_user(dp)) 338 return dp->bridge_dev == info->br; 339 340 return false; 341 } 342 343 int dsa_tag_8021q_bridge_join(struct dsa_switch *ds, 344 struct dsa_notifier_bridge_info *info) 345 { 346 struct dsa_switch *targeted_ds; 347 struct dsa_port *targeted_dp; 348 struct dsa_port *dp; 349 u16 targeted_rx_vid; 350 int err; 351 352 if (!ds->tag_8021q_ctx) 353 return 0; 354 355 targeted_ds = dsa_switch_find(info->tree_index, info->sw_index); 356 targeted_dp = dsa_to_port(targeted_ds, info->port); 357 targeted_rx_vid = dsa_tag_8021q_rx_vid(targeted_dp); 358 359 dsa_switch_for_each_port(dp, ds) { 360 u16 rx_vid = dsa_tag_8021q_rx_vid(dp); 361 362 if (!dsa_port_tag_8021q_bridge_match(dp, info)) 363 continue; 364 365 /* Install the RX VID of the targeted port in our VLAN table */ 366 err = dsa_port_tag_8021q_vlan_add(dp, targeted_rx_vid, true); 367 if (err) 368 return err; 369 370 /* Install our RX VID into the targeted port's VLAN table */ 371 err = dsa_port_tag_8021q_vlan_add(targeted_dp, rx_vid, true); 372 if (err) 373 return err; 374 } 375 376 return 0; 377 } 378 379 int dsa_tag_8021q_bridge_leave(struct dsa_switch *ds, 380 struct dsa_notifier_bridge_info *info) 381 { 382 struct dsa_switch *targeted_ds; 383 struct dsa_port *targeted_dp; 384 struct dsa_port *dp; 385 u16 targeted_rx_vid; 386 387 if (!ds->tag_8021q_ctx) 388 return 0; 389 390 targeted_ds = dsa_switch_find(info->tree_index, info->sw_index); 391 targeted_dp = dsa_to_port(targeted_ds, info->port); 392 targeted_rx_vid = dsa_tag_8021q_rx_vid(targeted_dp); 393 394 dsa_switch_for_each_port(dp, ds) { 395 u16 rx_vid = dsa_tag_8021q_rx_vid(dp); 396 397 if (!dsa_port_tag_8021q_bridge_match(dp, info)) 398 continue; 399 400 /* Remove the RX VID of the targeted port from our VLAN table */ 401 dsa_port_tag_8021q_vlan_del(dp, targeted_rx_vid, true); 402 403 /* Remove our RX VID from the targeted port's VLAN table */ 404 dsa_port_tag_8021q_vlan_del(targeted_dp, rx_vid, true); 405 } 406 407 return 0; 408 } 409 410 int dsa_tag_8021q_bridge_tx_fwd_offload(struct dsa_switch *ds, int port, 411 struct net_device *br, 412 int bridge_num) 413 { 414 u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num); 415 416 return dsa_port_tag_8021q_vlan_add(dsa_to_port(ds, port), tx_vid, 417 true); 418 } 419 EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_tx_fwd_offload); 420 421 void dsa_tag_8021q_bridge_tx_fwd_unoffload(struct dsa_switch *ds, int port, 422 struct net_device *br, 423 int bridge_num) 424 { 425 u16 tx_vid = dsa_8021q_bridge_tx_fwd_offload_vid(bridge_num); 426 427 dsa_port_tag_8021q_vlan_del(dsa_to_port(ds, port), tx_vid, true); 428 } 429 EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_tx_fwd_unoffload); 430 431 /* Set up a port's tag_8021q RX and TX VLAN for standalone mode operation */ 432 static int dsa_tag_8021q_port_setup(struct dsa_switch *ds, int port) 433 { 434 struct dsa_8021q_context *ctx = ds->tag_8021q_ctx; 435 struct dsa_port *dp = dsa_to_port(ds, port); 436 u16 rx_vid = dsa_tag_8021q_rx_vid(dp); 437 u16 tx_vid = dsa_tag_8021q_tx_vid(dp); 438 struct net_device *master; 439 int err; 440 441 /* The CPU port is implicitly configured by 442 * configuring the front-panel ports 443 */ 444 if (!dsa_port_is_user(dp)) 445 return 0; 446 447 master = dp->cpu_dp->master; 448 449 /* Add this user port's RX VID to the membership list of all others 450 * (including itself). This is so that bridging will not be hindered. 451 * L2 forwarding rules still take precedence when there are no VLAN 452 * restrictions, so there are no concerns about leaking traffic. 453 */ 454 err = dsa_port_tag_8021q_vlan_add(dp, rx_vid, false); 455 if (err) { 456 dev_err(ds->dev, 457 "Failed to apply RX VID %d to port %d: %pe\n", 458 rx_vid, port, ERR_PTR(err)); 459 return err; 460 } 461 462 /* Add @rx_vid to the master's RX filter. */ 463 vlan_vid_add(master, ctx->proto, rx_vid); 464 465 /* Finally apply the TX VID on this port and on the CPU port */ 466 err = dsa_port_tag_8021q_vlan_add(dp, tx_vid, false); 467 if (err) { 468 dev_err(ds->dev, 469 "Failed to apply TX VID %d on port %d: %pe\n", 470 tx_vid, port, ERR_PTR(err)); 471 return err; 472 } 473 474 return err; 475 } 476 477 static void dsa_tag_8021q_port_teardown(struct dsa_switch *ds, int port) 478 { 479 struct dsa_8021q_context *ctx = ds->tag_8021q_ctx; 480 struct dsa_port *dp = dsa_to_port(ds, port); 481 u16 rx_vid = dsa_tag_8021q_rx_vid(dp); 482 u16 tx_vid = dsa_tag_8021q_tx_vid(dp); 483 struct net_device *master; 484 485 /* The CPU port is implicitly configured by 486 * configuring the front-panel ports 487 */ 488 if (!dsa_port_is_user(dp)) 489 return; 490 491 master = dp->cpu_dp->master; 492 493 dsa_port_tag_8021q_vlan_del(dp, rx_vid, false); 494 495 vlan_vid_del(master, ctx->proto, rx_vid); 496 497 dsa_port_tag_8021q_vlan_del(dp, tx_vid, false); 498 } 499 500 static int dsa_tag_8021q_setup(struct dsa_switch *ds) 501 { 502 int err, port; 503 504 ASSERT_RTNL(); 505 506 for (port = 0; port < ds->num_ports; port++) { 507 err = dsa_tag_8021q_port_setup(ds, port); 508 if (err < 0) { 509 dev_err(ds->dev, 510 "Failed to setup VLAN tagging for port %d: %pe\n", 511 port, ERR_PTR(err)); 512 return err; 513 } 514 } 515 516 return 0; 517 } 518 519 static void dsa_tag_8021q_teardown(struct dsa_switch *ds) 520 { 521 int port; 522 523 ASSERT_RTNL(); 524 525 for (port = 0; port < ds->num_ports; port++) 526 dsa_tag_8021q_port_teardown(ds, port); 527 } 528 529 int dsa_tag_8021q_register(struct dsa_switch *ds, __be16 proto) 530 { 531 struct dsa_8021q_context *ctx; 532 533 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); 534 if (!ctx) 535 return -ENOMEM; 536 537 ctx->proto = proto; 538 ctx->ds = ds; 539 540 INIT_LIST_HEAD(&ctx->vlans); 541 542 ds->tag_8021q_ctx = ctx; 543 544 return dsa_tag_8021q_setup(ds); 545 } 546 EXPORT_SYMBOL_GPL(dsa_tag_8021q_register); 547 548 void dsa_tag_8021q_unregister(struct dsa_switch *ds) 549 { 550 struct dsa_8021q_context *ctx = ds->tag_8021q_ctx; 551 struct dsa_tag_8021q_vlan *v, *n; 552 553 dsa_tag_8021q_teardown(ds); 554 555 list_for_each_entry_safe(v, n, &ctx->vlans, list) { 556 list_del(&v->list); 557 kfree(v); 558 } 559 560 ds->tag_8021q_ctx = NULL; 561 562 kfree(ctx); 563 } 564 EXPORT_SYMBOL_GPL(dsa_tag_8021q_unregister); 565 566 struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev, 567 u16 tpid, u16 tci) 568 { 569 /* skb->data points at skb_mac_header, which 570 * is fine for vlan_insert_tag. 571 */ 572 return vlan_insert_tag(skb, htons(tpid), tci); 573 } 574 EXPORT_SYMBOL_GPL(dsa_8021q_xmit); 575 576 void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id) 577 { 578 u16 vid, tci; 579 580 skb_push_rcsum(skb, ETH_HLEN); 581 if (skb_vlan_tag_present(skb)) { 582 tci = skb_vlan_tag_get(skb); 583 __vlan_hwaccel_clear_tag(skb); 584 } else { 585 __skb_vlan_pop(skb, &tci); 586 } 587 skb_pull_rcsum(skb, ETH_HLEN); 588 589 vid = tci & VLAN_VID_MASK; 590 591 *source_port = dsa_8021q_rx_source_port(vid); 592 *switch_id = dsa_8021q_rx_switch_id(vid); 593 skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; 594 } 595 EXPORT_SYMBOL_GPL(dsa_8021q_rcv); 596