1 /* 2 * f_eem.c -- USB CDC Ethernet (EEM) link function driver 3 * 4 * Copyright (C) 2003-2005,2008 David Brownell 5 * Copyright (C) 2008 Nokia Corporation 6 * Copyright (C) 2009 EF Johnson Technologies 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/device.h> 17 #include <linux/etherdevice.h> 18 #include <linux/crc32.h> 19 #include <linux/slab.h> 20 21 #include "u_ether.h" 22 #include "u_ether_configfs.h" 23 #include "u_eem.h" 24 25 #define EEM_HLEN 2 26 27 /* 28 * This function is a "CDC Ethernet Emulation Model" (CDC EEM) 29 * Ethernet link. 30 */ 31 32 struct f_eem { 33 struct gether port; 34 u8 ctrl_id; 35 }; 36 37 static inline struct f_eem *func_to_eem(struct usb_function *f) 38 { 39 return container_of(f, struct f_eem, port.func); 40 } 41 42 /*-------------------------------------------------------------------------*/ 43 44 /* interface descriptor: */ 45 46 static struct usb_interface_descriptor eem_intf = { 47 .bLength = sizeof eem_intf, 48 .bDescriptorType = USB_DT_INTERFACE, 49 50 /* .bInterfaceNumber = DYNAMIC */ 51 .bNumEndpoints = 2, 52 .bInterfaceClass = USB_CLASS_COMM, 53 .bInterfaceSubClass = USB_CDC_SUBCLASS_EEM, 54 .bInterfaceProtocol = USB_CDC_PROTO_EEM, 55 /* .iInterface = DYNAMIC */ 56 }; 57 58 /* full speed support: */ 59 60 static struct usb_endpoint_descriptor eem_fs_in_desc = { 61 .bLength = USB_DT_ENDPOINT_SIZE, 62 .bDescriptorType = USB_DT_ENDPOINT, 63 64 .bEndpointAddress = USB_DIR_IN, 65 .bmAttributes = USB_ENDPOINT_XFER_BULK, 66 }; 67 68 static struct usb_endpoint_descriptor eem_fs_out_desc = { 69 .bLength = USB_DT_ENDPOINT_SIZE, 70 .bDescriptorType = USB_DT_ENDPOINT, 71 72 .bEndpointAddress = USB_DIR_OUT, 73 .bmAttributes = USB_ENDPOINT_XFER_BULK, 74 }; 75 76 static struct usb_descriptor_header *eem_fs_function[] = { 77 /* CDC EEM control descriptors */ 78 (struct usb_descriptor_header *) &eem_intf, 79 (struct usb_descriptor_header *) &eem_fs_in_desc, 80 (struct usb_descriptor_header *) &eem_fs_out_desc, 81 NULL, 82 }; 83 84 /* high speed support: */ 85 86 static struct usb_endpoint_descriptor eem_hs_in_desc = { 87 .bLength = USB_DT_ENDPOINT_SIZE, 88 .bDescriptorType = USB_DT_ENDPOINT, 89 90 .bEndpointAddress = USB_DIR_IN, 91 .bmAttributes = USB_ENDPOINT_XFER_BULK, 92 .wMaxPacketSize = cpu_to_le16(512), 93 }; 94 95 static struct usb_endpoint_descriptor eem_hs_out_desc = { 96 .bLength = USB_DT_ENDPOINT_SIZE, 97 .bDescriptorType = USB_DT_ENDPOINT, 98 99 .bEndpointAddress = USB_DIR_OUT, 100 .bmAttributes = USB_ENDPOINT_XFER_BULK, 101 .wMaxPacketSize = cpu_to_le16(512), 102 }; 103 104 static struct usb_descriptor_header *eem_hs_function[] = { 105 /* CDC EEM control descriptors */ 106 (struct usb_descriptor_header *) &eem_intf, 107 (struct usb_descriptor_header *) &eem_hs_in_desc, 108 (struct usb_descriptor_header *) &eem_hs_out_desc, 109 NULL, 110 }; 111 112 /* super speed support: */ 113 114 static struct usb_endpoint_descriptor eem_ss_in_desc = { 115 .bLength = USB_DT_ENDPOINT_SIZE, 116 .bDescriptorType = USB_DT_ENDPOINT, 117 118 .bEndpointAddress = USB_DIR_IN, 119 .bmAttributes = USB_ENDPOINT_XFER_BULK, 120 .wMaxPacketSize = cpu_to_le16(1024), 121 }; 122 123 static struct usb_endpoint_descriptor eem_ss_out_desc = { 124 .bLength = USB_DT_ENDPOINT_SIZE, 125 .bDescriptorType = USB_DT_ENDPOINT, 126 127 .bEndpointAddress = USB_DIR_OUT, 128 .bmAttributes = USB_ENDPOINT_XFER_BULK, 129 .wMaxPacketSize = cpu_to_le16(1024), 130 }; 131 132 static struct usb_ss_ep_comp_descriptor eem_ss_bulk_comp_desc = { 133 .bLength = sizeof eem_ss_bulk_comp_desc, 134 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, 135 136 /* the following 2 values can be tweaked if necessary */ 137 /* .bMaxBurst = 0, */ 138 /* .bmAttributes = 0, */ 139 }; 140 141 static struct usb_descriptor_header *eem_ss_function[] = { 142 /* CDC EEM control descriptors */ 143 (struct usb_descriptor_header *) &eem_intf, 144 (struct usb_descriptor_header *) &eem_ss_in_desc, 145 (struct usb_descriptor_header *) &eem_ss_bulk_comp_desc, 146 (struct usb_descriptor_header *) &eem_ss_out_desc, 147 (struct usb_descriptor_header *) &eem_ss_bulk_comp_desc, 148 NULL, 149 }; 150 151 /* string descriptors: */ 152 153 static struct usb_string eem_string_defs[] = { 154 [0].s = "CDC Ethernet Emulation Model (EEM)", 155 { } /* end of list */ 156 }; 157 158 static struct usb_gadget_strings eem_string_table = { 159 .language = 0x0409, /* en-us */ 160 .strings = eem_string_defs, 161 }; 162 163 static struct usb_gadget_strings *eem_strings[] = { 164 &eem_string_table, 165 NULL, 166 }; 167 168 /*-------------------------------------------------------------------------*/ 169 170 static int eem_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) 171 { 172 struct usb_composite_dev *cdev = f->config->cdev; 173 int value = -EOPNOTSUPP; 174 u16 w_index = le16_to_cpu(ctrl->wIndex); 175 u16 w_value = le16_to_cpu(ctrl->wValue); 176 u16 w_length = le16_to_cpu(ctrl->wLength); 177 178 DBG(cdev, "invalid control req%02x.%02x v%04x i%04x l%d\n", 179 ctrl->bRequestType, ctrl->bRequest, 180 w_value, w_index, w_length); 181 182 /* device either stalls (value < 0) or reports success */ 183 return value; 184 } 185 186 187 static int eem_set_alt(struct usb_function *f, unsigned intf, unsigned alt) 188 { 189 struct f_eem *eem = func_to_eem(f); 190 struct usb_composite_dev *cdev = f->config->cdev; 191 struct net_device *net; 192 193 /* we know alt == 0, so this is an activation or a reset */ 194 if (alt != 0) 195 goto fail; 196 197 if (intf == eem->ctrl_id) { 198 199 if (eem->port.in_ep->driver_data) { 200 DBG(cdev, "reset eem\n"); 201 gether_disconnect(&eem->port); 202 } 203 204 if (!eem->port.in_ep->desc || !eem->port.out_ep->desc) { 205 DBG(cdev, "init eem\n"); 206 if (config_ep_by_speed(cdev->gadget, f, 207 eem->port.in_ep) || 208 config_ep_by_speed(cdev->gadget, f, 209 eem->port.out_ep)) { 210 eem->port.in_ep->desc = NULL; 211 eem->port.out_ep->desc = NULL; 212 goto fail; 213 } 214 } 215 216 /* zlps should not occur because zero-length EEM packets 217 * will be inserted in those cases where they would occur 218 */ 219 eem->port.is_zlp_ok = 1; 220 eem->port.cdc_filter = DEFAULT_FILTER; 221 DBG(cdev, "activate eem\n"); 222 net = gether_connect(&eem->port); 223 if (IS_ERR(net)) 224 return PTR_ERR(net); 225 } else 226 goto fail; 227 228 return 0; 229 fail: 230 return -EINVAL; 231 } 232 233 static void eem_disable(struct usb_function *f) 234 { 235 struct f_eem *eem = func_to_eem(f); 236 struct usb_composite_dev *cdev = f->config->cdev; 237 238 DBG(cdev, "eem deactivated\n"); 239 240 if (eem->port.in_ep->driver_data) 241 gether_disconnect(&eem->port); 242 } 243 244 /*-------------------------------------------------------------------------*/ 245 246 /* EEM function driver setup/binding */ 247 248 static int eem_bind(struct usb_configuration *c, struct usb_function *f) 249 { 250 struct usb_composite_dev *cdev = c->cdev; 251 struct f_eem *eem = func_to_eem(f); 252 struct usb_string *us; 253 int status; 254 struct usb_ep *ep; 255 256 struct f_eem_opts *eem_opts; 257 258 eem_opts = container_of(f->fi, struct f_eem_opts, func_inst); 259 /* 260 * in drivers/usb/gadget/configfs.c:configfs_composite_bind() 261 * configurations are bound in sequence with list_for_each_entry, 262 * in each configuration its functions are bound in sequence 263 * with list_for_each_entry, so we assume no race condition 264 * with regard to eem_opts->bound access 265 */ 266 if (!eem_opts->bound) { 267 mutex_lock(&eem_opts->lock); 268 gether_set_gadget(eem_opts->net, cdev->gadget); 269 status = gether_register_netdev(eem_opts->net); 270 mutex_unlock(&eem_opts->lock); 271 if (status) 272 return status; 273 eem_opts->bound = true; 274 } 275 276 us = usb_gstrings_attach(cdev, eem_strings, 277 ARRAY_SIZE(eem_string_defs)); 278 if (IS_ERR(us)) 279 return PTR_ERR(us); 280 eem_intf.iInterface = us[0].id; 281 282 /* allocate instance-specific interface IDs */ 283 status = usb_interface_id(c, f); 284 if (status < 0) 285 goto fail; 286 eem->ctrl_id = status; 287 eem_intf.bInterfaceNumber = status; 288 289 status = -ENODEV; 290 291 /* allocate instance-specific endpoints */ 292 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_in_desc); 293 if (!ep) 294 goto fail; 295 eem->port.in_ep = ep; 296 ep->driver_data = cdev; /* claim */ 297 298 ep = usb_ep_autoconfig(cdev->gadget, &eem_fs_out_desc); 299 if (!ep) 300 goto fail; 301 eem->port.out_ep = ep; 302 ep->driver_data = cdev; /* claim */ 303 304 status = -ENOMEM; 305 306 /* support all relevant hardware speeds... we expect that when 307 * hardware is dual speed, all bulk-capable endpoints work at 308 * both speeds 309 */ 310 eem_hs_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress; 311 eem_hs_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress; 312 313 eem_ss_in_desc.bEndpointAddress = eem_fs_in_desc.bEndpointAddress; 314 eem_ss_out_desc.bEndpointAddress = eem_fs_out_desc.bEndpointAddress; 315 316 status = usb_assign_descriptors(f, eem_fs_function, eem_hs_function, 317 eem_ss_function); 318 if (status) 319 goto fail; 320 321 DBG(cdev, "CDC Ethernet (EEM): %s speed IN/%s OUT/%s\n", 322 gadget_is_superspeed(c->cdev->gadget) ? "super" : 323 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", 324 eem->port.in_ep->name, eem->port.out_ep->name); 325 return 0; 326 327 fail: 328 usb_free_all_descriptors(f); 329 if (eem->port.out_ep) 330 eem->port.out_ep->driver_data = NULL; 331 if (eem->port.in_ep) 332 eem->port.in_ep->driver_data = NULL; 333 334 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); 335 336 return status; 337 } 338 339 static void eem_cmd_complete(struct usb_ep *ep, struct usb_request *req) 340 { 341 struct sk_buff *skb = (struct sk_buff *)req->context; 342 343 dev_kfree_skb_any(skb); 344 } 345 346 /* 347 * Add the EEM header and ethernet checksum. 348 * We currently do not attempt to put multiple ethernet frames 349 * into a single USB transfer 350 */ 351 static struct sk_buff *eem_wrap(struct gether *port, struct sk_buff *skb) 352 { 353 struct sk_buff *skb2 = NULL; 354 struct usb_ep *in = port->in_ep; 355 int padlen = 0; 356 u16 len = skb->len; 357 358 int headroom = skb_headroom(skb); 359 int tailroom = skb_tailroom(skb); 360 361 /* When (len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) is 0, 362 * stick two bytes of zero-length EEM packet on the end. 363 */ 364 if (((len + EEM_HLEN + ETH_FCS_LEN) % in->maxpacket) == 0) 365 padlen += 2; 366 367 if ((tailroom >= (ETH_FCS_LEN + padlen)) && 368 (headroom >= EEM_HLEN) && !skb_cloned(skb)) 369 goto done; 370 371 skb2 = skb_copy_expand(skb, EEM_HLEN, ETH_FCS_LEN + padlen, GFP_ATOMIC); 372 dev_kfree_skb_any(skb); 373 skb = skb2; 374 if (!skb) 375 return skb; 376 377 done: 378 /* use the "no CRC" option */ 379 put_unaligned_be32(0xdeadbeef, skb_put(skb, 4)); 380 381 /* EEM packet header format: 382 * b0..13: length of ethernet frame 383 * b14: bmCRC (0 == sentinel CRC) 384 * b15: bmType (0 == data) 385 */ 386 len = skb->len; 387 put_unaligned_le16(len & 0x3FFF, skb_push(skb, 2)); 388 389 /* add a zero-length EEM packet, if needed */ 390 if (padlen) 391 put_unaligned_le16(0, skb_put(skb, 2)); 392 393 return skb; 394 } 395 396 /* 397 * Remove the EEM header. Note that there can be many EEM packets in a single 398 * USB transfer, so we need to break them out and handle them independently. 399 */ 400 static int eem_unwrap(struct gether *port, 401 struct sk_buff *skb, 402 struct sk_buff_head *list) 403 { 404 struct usb_composite_dev *cdev = port->func.config->cdev; 405 int status = 0; 406 407 do { 408 struct sk_buff *skb2; 409 u16 header; 410 u16 len = 0; 411 412 if (skb->len < EEM_HLEN) { 413 status = -EINVAL; 414 DBG(cdev, "invalid EEM header\n"); 415 goto error; 416 } 417 418 /* remove the EEM header */ 419 header = get_unaligned_le16(skb->data); 420 skb_pull(skb, EEM_HLEN); 421 422 /* EEM packet header format: 423 * b0..14: EEM type dependent (data or command) 424 * b15: bmType (0 == data, 1 == command) 425 */ 426 if (header & BIT(15)) { 427 struct usb_request *req = cdev->req; 428 u16 bmEEMCmd; 429 430 /* EEM command packet format: 431 * b0..10: bmEEMCmdParam 432 * b11..13: bmEEMCmd 433 * b14: reserved (must be zero) 434 * b15: bmType (1 == command) 435 */ 436 if (header & BIT(14)) 437 continue; 438 439 bmEEMCmd = (header >> 11) & 0x7; 440 switch (bmEEMCmd) { 441 case 0: /* echo */ 442 len = header & 0x7FF; 443 if (skb->len < len) { 444 status = -EOVERFLOW; 445 goto error; 446 } 447 448 skb2 = skb_clone(skb, GFP_ATOMIC); 449 if (unlikely(!skb2)) { 450 DBG(cdev, "EEM echo response error\n"); 451 goto next; 452 } 453 skb_trim(skb2, len); 454 put_unaligned_le16(BIT(15) | BIT(11) | len, 455 skb_push(skb2, 2)); 456 skb_copy_bits(skb2, 0, req->buf, skb2->len); 457 req->length = skb2->len; 458 req->complete = eem_cmd_complete; 459 req->zero = 1; 460 req->context = skb2; 461 if (usb_ep_queue(port->in_ep, req, GFP_ATOMIC)) 462 DBG(cdev, "echo response queue fail\n"); 463 break; 464 465 case 1: /* echo response */ 466 case 2: /* suspend hint */ 467 case 3: /* response hint */ 468 case 4: /* response complete hint */ 469 case 5: /* tickle */ 470 default: /* reserved */ 471 continue; 472 } 473 } else { 474 u32 crc, crc2; 475 struct sk_buff *skb3; 476 477 /* check for zero-length EEM packet */ 478 if (header == 0) 479 continue; 480 481 /* EEM data packet format: 482 * b0..13: length of ethernet frame 483 * b14: bmCRC (0 == sentinel, 1 == calculated) 484 * b15: bmType (0 == data) 485 */ 486 len = header & 0x3FFF; 487 if ((skb->len < len) 488 || (len < (ETH_HLEN + ETH_FCS_LEN))) { 489 status = -EINVAL; 490 goto error; 491 } 492 493 /* validate CRC */ 494 if (header & BIT(14)) { 495 crc = get_unaligned_le32(skb->data + len 496 - ETH_FCS_LEN); 497 crc2 = ~crc32_le(~0, 498 skb->data, len - ETH_FCS_LEN); 499 } else { 500 crc = get_unaligned_be32(skb->data + len 501 - ETH_FCS_LEN); 502 crc2 = 0xdeadbeef; 503 } 504 if (crc != crc2) { 505 DBG(cdev, "invalid EEM CRC\n"); 506 goto next; 507 } 508 509 skb2 = skb_clone(skb, GFP_ATOMIC); 510 if (unlikely(!skb2)) { 511 DBG(cdev, "unable to unframe EEM packet\n"); 512 continue; 513 } 514 skb_trim(skb2, len - ETH_FCS_LEN); 515 516 skb3 = skb_copy_expand(skb2, 517 NET_IP_ALIGN, 518 0, 519 GFP_ATOMIC); 520 if (unlikely(!skb3)) { 521 DBG(cdev, "unable to realign EEM packet\n"); 522 dev_kfree_skb_any(skb2); 523 continue; 524 } 525 dev_kfree_skb_any(skb2); 526 skb_queue_tail(list, skb3); 527 } 528 next: 529 skb_pull(skb, len); 530 } while (skb->len); 531 532 error: 533 dev_kfree_skb_any(skb); 534 return status; 535 } 536 537 static inline struct f_eem_opts *to_f_eem_opts(struct config_item *item) 538 { 539 return container_of(to_config_group(item), struct f_eem_opts, 540 func_inst.group); 541 } 542 543 /* f_eem_item_ops */ 544 USB_ETHERNET_CONFIGFS_ITEM(eem); 545 546 /* f_eem_opts_dev_addr */ 547 USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(eem); 548 549 /* f_eem_opts_host_addr */ 550 USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(eem); 551 552 /* f_eem_opts_qmult */ 553 USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(eem); 554 555 /* f_eem_opts_ifname */ 556 USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(eem); 557 558 static struct configfs_attribute *eem_attrs[] = { 559 &f_eem_opts_dev_addr.attr, 560 &f_eem_opts_host_addr.attr, 561 &f_eem_opts_qmult.attr, 562 &f_eem_opts_ifname.attr, 563 NULL, 564 }; 565 566 static struct config_item_type eem_func_type = { 567 .ct_item_ops = &eem_item_ops, 568 .ct_attrs = eem_attrs, 569 .ct_owner = THIS_MODULE, 570 }; 571 572 static void eem_free_inst(struct usb_function_instance *f) 573 { 574 struct f_eem_opts *opts; 575 576 opts = container_of(f, struct f_eem_opts, func_inst); 577 if (opts->bound) 578 gether_cleanup(netdev_priv(opts->net)); 579 else 580 free_netdev(opts->net); 581 kfree(opts); 582 } 583 584 static struct usb_function_instance *eem_alloc_inst(void) 585 { 586 struct f_eem_opts *opts; 587 588 opts = kzalloc(sizeof(*opts), GFP_KERNEL); 589 if (!opts) 590 return ERR_PTR(-ENOMEM); 591 mutex_init(&opts->lock); 592 opts->func_inst.free_func_inst = eem_free_inst; 593 opts->net = gether_setup_default(); 594 if (IS_ERR(opts->net)) { 595 struct net_device *net = opts->net; 596 kfree(opts); 597 return ERR_CAST(net); 598 } 599 600 config_group_init_type_name(&opts->func_inst.group, "", &eem_func_type); 601 602 return &opts->func_inst; 603 } 604 605 static void eem_free(struct usb_function *f) 606 { 607 struct f_eem *eem; 608 struct f_eem_opts *opts; 609 610 eem = func_to_eem(f); 611 opts = container_of(f->fi, struct f_eem_opts, func_inst); 612 kfree(eem); 613 mutex_lock(&opts->lock); 614 opts->refcnt--; 615 mutex_unlock(&opts->lock); 616 } 617 618 static void eem_unbind(struct usb_configuration *c, struct usb_function *f) 619 { 620 DBG(c->cdev, "eem unbind\n"); 621 622 usb_free_all_descriptors(f); 623 } 624 625 static struct usb_function *eem_alloc(struct usb_function_instance *fi) 626 { 627 struct f_eem *eem; 628 struct f_eem_opts *opts; 629 630 /* allocate and initialize one new instance */ 631 eem = kzalloc(sizeof(*eem), GFP_KERNEL); 632 if (!eem) 633 return ERR_PTR(-ENOMEM); 634 635 opts = container_of(fi, struct f_eem_opts, func_inst); 636 mutex_lock(&opts->lock); 637 opts->refcnt++; 638 639 eem->port.ioport = netdev_priv(opts->net); 640 mutex_unlock(&opts->lock); 641 eem->port.cdc_filter = DEFAULT_FILTER; 642 643 eem->port.func.name = "cdc_eem"; 644 /* descriptors are per-instance copies */ 645 eem->port.func.bind = eem_bind; 646 eem->port.func.unbind = eem_unbind; 647 eem->port.func.set_alt = eem_set_alt; 648 eem->port.func.setup = eem_setup; 649 eem->port.func.disable = eem_disable; 650 eem->port.func.free_func = eem_free; 651 eem->port.wrap = eem_wrap; 652 eem->port.unwrap = eem_unwrap; 653 eem->port.header_len = EEM_HLEN; 654 655 return &eem->port.func; 656 } 657 658 DECLARE_USB_FUNCTION_INIT(eem, eem_alloc_inst, eem_alloc); 659 MODULE_LICENSE("GPL"); 660 MODULE_AUTHOR("David Brownell"); 661