linux/drivers/net/wan/hdlc_fr.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Generic HDLC support routines for Linux
   4 * Frame Relay support
   5 *
   6 * Copyright (C) 1999 - 2006 Krzysztof Halasa <khc@pm.waw.pl>
   7 *
   8
   9        Theory of PVC state
  10
  11 DCE mode:
  12
  13 (exist,new) -> 0,0 when "PVC create" or if "link unreliable"
  14         0,x -> 1,1 if "link reliable" when sending FULL STATUS
  15         1,1 -> 1,0 if received FULL STATUS ACK
  16
  17 (active)    -> 0 when "ifconfig PVC down" or "link unreliable" or "PVC create"
  18             -> 1 when "PVC up" and (exist,new) = 1,0
  19
  20 DTE mode:
  21 (exist,new,active) = FULL STATUS if "link reliable"
  22                    = 0, 0, 0 if "link unreliable"
  23 No LMI:
  24 active = open and "link reliable"
  25 exist = new = not used
  26
  27 CCITT LMI: ITU-T Q.933 Annex A
  28 ANSI LMI: ANSI T1.617 Annex D
  29 CISCO LMI: the original, aka "Gang of Four" LMI
  30
  31*/
  32
  33#include <linux/errno.h>
  34#include <linux/etherdevice.h>
  35#include <linux/hdlc.h>
  36#include <linux/if_arp.h>
  37#include <linux/inetdevice.h>
  38#include <linux/init.h>
  39#include <linux/kernel.h>
  40#include <linux/module.h>
  41#include <linux/pkt_sched.h>
  42#include <linux/poll.h>
  43#include <linux/rtnetlink.h>
  44#include <linux/skbuff.h>
  45#include <linux/slab.h>
  46
  47#undef DEBUG_PKT
  48#undef DEBUG_ECN
  49#undef DEBUG_LINK
  50#undef DEBUG_PROTO
  51#undef DEBUG_PVC
  52
  53#define FR_UI                   0x03
  54#define FR_PAD                  0x00
  55
  56#define NLPID_IP                0xCC
  57#define NLPID_IPV6              0x8E
  58#define NLPID_SNAP              0x80
  59#define NLPID_PAD               0x00
  60#define NLPID_CCITT_ANSI_LMI    0x08
  61#define NLPID_CISCO_LMI         0x09
  62
  63#define LMI_CCITT_ANSI_DLCI        0 /* LMI DLCI */
  64#define LMI_CISCO_DLCI          1023
  65
  66#define LMI_CALLREF             0x00 /* Call Reference */
  67#define LMI_ANSI_LOCKSHIFT      0x95 /* ANSI locking shift */
  68#define LMI_ANSI_CISCO_REPTYPE  0x01 /* report type */
  69#define LMI_CCITT_REPTYPE       0x51
  70#define LMI_ANSI_CISCO_ALIVE    0x03 /* keep alive */
  71#define LMI_CCITT_ALIVE         0x53
  72#define LMI_ANSI_CISCO_PVCSTAT  0x07 /* PVC status */
  73#define LMI_CCITT_PVCSTAT       0x57
  74
  75#define LMI_FULLREP             0x00 /* full report  */
  76#define LMI_INTEGRITY           0x01 /* link integrity report */
  77#define LMI_SINGLE              0x02 /* single PVC report */
  78
  79#define LMI_STATUS_ENQUIRY      0x75
  80#define LMI_STATUS              0x7D /* reply */
  81
  82#define LMI_REPT_LEN               1 /* report type element length */
  83#define LMI_INTEG_LEN              2 /* link integrity element length */
  84
  85#define LMI_CCITT_CISCO_LENGTH    13 /* LMI frame lengths */
  86#define LMI_ANSI_LENGTH           14
  87
  88struct fr_hdr {
  89#if defined(__LITTLE_ENDIAN_BITFIELD)
  90        unsigned ea1:   1;
  91        unsigned cr:    1;
  92        unsigned dlcih: 6;
  93
  94        unsigned ea2:   1;
  95        unsigned de:    1;
  96        unsigned becn:  1;
  97        unsigned fecn:  1;
  98        unsigned dlcil: 4;
  99#else
 100        unsigned dlcih: 6;
 101        unsigned cr:    1;
 102        unsigned ea1:   1;
 103
 104        unsigned dlcil: 4;
 105        unsigned fecn:  1;
 106        unsigned becn:  1;
 107        unsigned de:    1;
 108        unsigned ea2:   1;
 109#endif
 110} __packed;
 111
 112struct pvc_device {
 113        struct net_device *frad;
 114        struct net_device *main;
 115        struct net_device *ether;       /* bridged Ethernet interface   */
 116        struct pvc_device *next;        /* Sorted in ascending DLCI order */
 117        int dlci;
 118        int open_count;
 119
 120        struct {
 121                unsigned int new: 1;
 122                unsigned int active: 1;
 123                unsigned int exist: 1;
 124                unsigned int deleted: 1;
 125                unsigned int fecn: 1;
 126                unsigned int becn: 1;
 127                unsigned int bandwidth; /* Cisco LMI reporting only */
 128        } state;
 129};
 130
 131struct frad_state {
 132        fr_proto settings;
 133        struct pvc_device *first_pvc;
 134        int dce_pvc_count;
 135
 136        struct timer_list timer;
 137        struct net_device *dev;
 138        unsigned long last_poll;
 139        int reliable;
 140        int dce_changed;
 141        int request;
 142        int fullrep_sent;
 143        u32 last_errors; /* last errors bit list */
 144        u8 n391cnt;
 145        u8 txseq; /* TX sequence number */
 146        u8 rxseq; /* RX sequence number */
 147};
 148
 149static int fr_ioctl(struct net_device *dev, struct if_settings *ifs);
 150
 151static inline u16 q922_to_dlci(u8 *hdr)
 152{
 153        return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
 154}
 155
 156static inline void dlci_to_q922(u8 *hdr, u16 dlci)
 157{
 158        hdr[0] = (dlci >> 2) & 0xFC;
 159        hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
 160}
 161
 162static inline struct frad_state *state(hdlc_device *hdlc)
 163{
 164        return (struct frad_state *)(hdlc->state);
 165}
 166
 167static inline struct pvc_device *find_pvc(hdlc_device *hdlc, u16 dlci)
 168{
 169        struct pvc_device *pvc = state(hdlc)->first_pvc;
 170
 171        while (pvc) {
 172                if (pvc->dlci == dlci)
 173                        return pvc;
 174                if (pvc->dlci > dlci)
 175                        return NULL; /* the list is sorted */
 176                pvc = pvc->next;
 177        }
 178
 179        return NULL;
 180}
 181
 182static struct pvc_device *add_pvc(struct net_device *dev, u16 dlci)
 183{
 184        hdlc_device *hdlc = dev_to_hdlc(dev);
 185        struct pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
 186
 187        while (*pvc_p) {
 188                if ((*pvc_p)->dlci == dlci)
 189                        return *pvc_p;
 190                if ((*pvc_p)->dlci > dlci)
 191                        break;  /* the list is sorted */
 192                pvc_p = &(*pvc_p)->next;
 193        }
 194
 195        pvc = kzalloc(sizeof(*pvc), GFP_ATOMIC);
 196#ifdef DEBUG_PVC
 197        printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
 198#endif
 199        if (!pvc)
 200                return NULL;
 201
 202        pvc->dlci = dlci;
 203        pvc->frad = dev;
 204        pvc->next = *pvc_p;     /* Put it in the chain */
 205        *pvc_p = pvc;
 206        return pvc;
 207}
 208
 209static inline int pvc_is_used(struct pvc_device *pvc)
 210{
 211        return pvc->main || pvc->ether;
 212}
 213
 214static inline void pvc_carrier(int on, struct pvc_device *pvc)
 215{
 216        if (on) {
 217                if (pvc->main)
 218                        if (!netif_carrier_ok(pvc->main))
 219                                netif_carrier_on(pvc->main);
 220                if (pvc->ether)
 221                        if (!netif_carrier_ok(pvc->ether))
 222                                netif_carrier_on(pvc->ether);
 223        } else {
 224                if (pvc->main)
 225                        if (netif_carrier_ok(pvc->main))
 226                                netif_carrier_off(pvc->main);
 227                if (pvc->ether)
 228                        if (netif_carrier_ok(pvc->ether))
 229                                netif_carrier_off(pvc->ether);
 230        }
 231}
 232
 233static inline void delete_unused_pvcs(hdlc_device *hdlc)
 234{
 235        struct pvc_device **pvc_p = &state(hdlc)->first_pvc;
 236
 237        while (*pvc_p) {
 238                if (!pvc_is_used(*pvc_p)) {
 239                        struct pvc_device *pvc = *pvc_p;
 240#ifdef DEBUG_PVC
 241                        printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
 242#endif
 243                        *pvc_p = pvc->next;
 244                        kfree(pvc);
 245                        continue;
 246                }
 247                pvc_p = &(*pvc_p)->next;
 248        }
 249}
 250
 251static inline struct net_device **get_dev_p(struct pvc_device *pvc,
 252                                            int type)
 253{
 254        if (type == ARPHRD_ETHER)
 255                return &pvc->ether;
 256        else
 257                return &pvc->main;
 258}
 259
 260static int fr_hard_header(struct sk_buff *skb, u16 dlci)
 261{
 262        if (!skb->dev) { /* Control packets */
 263                switch (dlci) {
 264                case LMI_CCITT_ANSI_DLCI:
 265                        skb_push(skb, 4);
 266                        skb->data[3] = NLPID_CCITT_ANSI_LMI;
 267                        break;
 268
 269                case LMI_CISCO_DLCI:
 270                        skb_push(skb, 4);
 271                        skb->data[3] = NLPID_CISCO_LMI;
 272                        break;
 273
 274                default:
 275                        return -EINVAL;
 276                }
 277
 278        } else if (skb->dev->type == ARPHRD_DLCI) {
 279                switch (skb->protocol) {
 280                case htons(ETH_P_IP):
 281                        skb_push(skb, 4);
 282                        skb->data[3] = NLPID_IP;
 283                        break;
 284
 285                case htons(ETH_P_IPV6):
 286                        skb_push(skb, 4);
 287                        skb->data[3] = NLPID_IPV6;
 288                        break;
 289
 290                default:
 291                        skb_push(skb, 10);
 292                        skb->data[3] = FR_PAD;
 293                        skb->data[4] = NLPID_SNAP;
 294                        /* OUI 00-00-00 indicates an Ethertype follows */
 295                        skb->data[5] = 0x00;
 296                        skb->data[6] = 0x00;
 297                        skb->data[7] = 0x00;
 298                        /* This should be an Ethertype: */
 299                        *(__be16 *)(skb->data + 8) = skb->protocol;
 300                }
 301
 302        } else if (skb->dev->type == ARPHRD_ETHER) {
 303                skb_push(skb, 10);
 304                skb->data[3] = FR_PAD;
 305                skb->data[4] = NLPID_SNAP;
 306                /* OUI 00-80-C2 stands for the 802.1 organization */
 307                skb->data[5] = 0x00;
 308                skb->data[6] = 0x80;
 309                skb->data[7] = 0xC2;
 310                /* PID 00-07 stands for Ethernet frames without FCS */
 311                skb->data[8] = 0x00;
 312                skb->data[9] = 0x07;
 313
 314        } else {
 315                return -EINVAL;
 316        }
 317
 318        dlci_to_q922(skb->data, dlci);
 319        skb->data[2] = FR_UI;
 320        return 0;
 321}
 322
 323static int pvc_open(struct net_device *dev)
 324{
 325        struct pvc_device *pvc = dev->ml_priv;
 326
 327        if ((pvc->frad->flags & IFF_UP) == 0)
 328                return -EIO;  /* Frad must be UP in order to activate PVC */
 329
 330        if (pvc->open_count++ == 0) {
 331                hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
 332
 333                if (state(hdlc)->settings.lmi == LMI_NONE)
 334                        pvc->state.active = netif_carrier_ok(pvc->frad);
 335
 336                pvc_carrier(pvc->state.active, pvc);
 337                state(hdlc)->dce_changed = 1;
 338        }
 339        return 0;
 340}
 341
 342static int pvc_close(struct net_device *dev)
 343{
 344        struct pvc_device *pvc = dev->ml_priv;
 345
 346        if (--pvc->open_count == 0) {
 347                hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
 348
 349                if (state(hdlc)->settings.lmi == LMI_NONE)
 350                        pvc->state.active = 0;
 351
 352                if (state(hdlc)->settings.dce) {
 353                        state(hdlc)->dce_changed = 1;
 354                        pvc->state.active = 0;
 355                }
 356        }
 357        return 0;
 358}
 359
 360static int pvc_ioctl(struct net_device *dev, struct if_settings *ifs)
 361{
 362        struct pvc_device *pvc = dev->ml_priv;
 363        fr_proto_pvc_info info;
 364
 365        if (ifs->type == IF_GET_PROTO) {
 366                if (dev->type == ARPHRD_ETHER)
 367                        ifs->type = IF_PROTO_FR_ETH_PVC;
 368                else
 369                        ifs->type = IF_PROTO_FR_PVC;
 370
 371                if (ifs->size < sizeof(info)) {
 372                        /* data size wanted */
 373                        ifs->size = sizeof(info);
 374                        return -ENOBUFS;
 375                }
 376
 377                info.dlci = pvc->dlci;
 378                memcpy(info.master, pvc->frad->name, IFNAMSIZ);
 379                if (copy_to_user(ifs->ifs_ifsu.fr_pvc_info,
 380                                 &info, sizeof(info)))
 381                        return -EFAULT;
 382                return 0;
 383        }
 384
 385        return -EINVAL;
 386}
 387
 388static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
 389{
 390        struct pvc_device *pvc = dev->ml_priv;
 391
 392        if (!pvc->state.active)
 393                goto drop;
 394
 395        if (dev->type == ARPHRD_ETHER) {
 396                int pad = ETH_ZLEN - skb->len;
 397
 398                if (pad > 0) { /* Pad the frame with zeros */
 399                        if (__skb_pad(skb, pad, false))
 400                                goto drop;
 401                        skb_put(skb, pad);
 402                }
 403        }
 404
 405        /* We already requested the header space with dev->needed_headroom.
 406         * So this is just a protection in case the upper layer didn't take
 407         * dev->needed_headroom into consideration.
 408         */
 409        if (skb_headroom(skb) < 10) {
 410                struct sk_buff *skb2 = skb_realloc_headroom(skb, 10);
 411
 412                if (!skb2)
 413                        goto drop;
 414                dev_kfree_skb(skb);
 415                skb = skb2;
 416        }
 417
 418        skb->dev = dev;
 419        if (fr_hard_header(skb, pvc->dlci))
 420                goto drop;
 421
 422        dev->stats.tx_bytes += skb->len;
 423        dev->stats.tx_packets++;
 424        if (pvc->state.fecn) /* TX Congestion counter */
 425                dev->stats.tx_compressed++;
 426        skb->dev = pvc->frad;
 427        skb->protocol = htons(ETH_P_HDLC);
 428        skb_reset_network_header(skb);
 429        dev_queue_xmit(skb);
 430        return NETDEV_TX_OK;
 431
 432drop:
 433        dev->stats.tx_dropped++;
 434        kfree_skb(skb);
 435        return NETDEV_TX_OK;
 436}
 437
 438static inline void fr_log_dlci_active(struct pvc_device *pvc)
 439{
 440        netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
 441                    pvc->dlci,
 442                    pvc->main ? pvc->main->name : "",
 443                    pvc->main && pvc->ether ? " " : "",
 444                    pvc->ether ? pvc->ether->name : "",
 445                    pvc->state.new ? " new" : "",
 446                    !pvc->state.exist ? "deleted" :
 447                    pvc->state.active ? "active" : "inactive");
 448}
 449
 450static inline u8 fr_lmi_nextseq(u8 x)
 451{
 452        x++;
 453        return x ? x : 1;
 454}
 455
 456static void fr_lmi_send(struct net_device *dev, int fullrep)
 457{
 458        hdlc_device *hdlc = dev_to_hdlc(dev);
 459        struct sk_buff *skb;
 460        struct pvc_device *pvc = state(hdlc)->first_pvc;
 461        int lmi = state(hdlc)->settings.lmi;
 462        int dce = state(hdlc)->settings.dce;
 463        int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
 464        int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
 465        u8 *data;
 466        int i = 0;
 467
 468        if (dce && fullrep) {
 469                len += state(hdlc)->dce_pvc_count * (2 + stat_len);
 470                if (len > HDLC_MAX_MRU) {
 471                        netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
 472                        return;
 473                }
 474        }
 475
 476        skb = dev_alloc_skb(len);
 477        if (!skb)
 478                return;
 479
 480        memset(skb->data, 0, len);
 481        skb_reserve(skb, 4);
 482        if (lmi == LMI_CISCO)
 483                fr_hard_header(skb, LMI_CISCO_DLCI);
 484        else
 485                fr_hard_header(skb, LMI_CCITT_ANSI_DLCI);
 486
 487        data = skb_tail_pointer(skb);
 488        data[i++] = LMI_CALLREF;
 489        data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
 490        if (lmi == LMI_ANSI)
 491                data[i++] = LMI_ANSI_LOCKSHIFT;
 492        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
 493                LMI_ANSI_CISCO_REPTYPE;
 494        data[i++] = LMI_REPT_LEN;
 495        data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
 496        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
 497        data[i++] = LMI_INTEG_LEN;
 498        data[i++] = state(hdlc)->txseq =
 499                fr_lmi_nextseq(state(hdlc)->txseq);
 500        data[i++] = state(hdlc)->rxseq;
 501
 502        if (dce && fullrep) {
 503                while (pvc) {
 504                        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
 505                                LMI_ANSI_CISCO_PVCSTAT;
 506                        data[i++] = stat_len;
 507
 508                        /* LMI start/restart */
 509                        if (state(hdlc)->reliable && !pvc->state.exist) {
 510                                pvc->state.exist = pvc->state.new = 1;
 511                                fr_log_dlci_active(pvc);
 512                        }
 513
 514                        /* ifconfig PVC up */
 515                        if (pvc->open_count && !pvc->state.active &&
 516                            pvc->state.exist && !pvc->state.new) {
 517                                pvc_carrier(1, pvc);
 518                                pvc->state.active = 1;
 519                                fr_log_dlci_active(pvc);
 520                        }
 521
 522                        if (lmi == LMI_CISCO) {
 523                                data[i] = pvc->dlci >> 8;
 524                                data[i + 1] = pvc->dlci & 0xFF;
 525                        } else {
 526                                data[i] = (pvc->dlci >> 4) & 0x3F;
 527                                data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
 528                                data[i + 2] = 0x80;
 529                        }
 530
 531                        if (pvc->state.new)
 532                                data[i + 2] |= 0x08;
 533                        else if (pvc->state.active)
 534                                data[i + 2] |= 0x02;
 535
 536                        i += stat_len;
 537                        pvc = pvc->next;
 538                }
 539        }
 540
 541        skb_put(skb, i);
 542        skb->priority = TC_PRIO_CONTROL;
 543        skb->dev = dev;
 544        skb->protocol = htons(ETH_P_HDLC);
 545        skb_reset_network_header(skb);
 546
 547        dev_queue_xmit(skb);
 548}
 549
 550static void fr_set_link_state(int reliable, struct net_device *dev)
 551{
 552        hdlc_device *hdlc = dev_to_hdlc(dev);
 553        struct pvc_device *pvc = state(hdlc)->first_pvc;
 554
 555        state(hdlc)->reliable = reliable;
 556        if (reliable) {
 557                netif_dormant_off(dev);
 558                state(hdlc)->n391cnt = 0; /* Request full status */
 559                state(hdlc)->dce_changed = 1;
 560
 561                if (state(hdlc)->settings.lmi == LMI_NONE) {
 562                        while (pvc) {   /* Activate all PVCs */
 563                                pvc_carrier(1, pvc);
 564                                pvc->state.exist = pvc->state.active = 1;
 565                                pvc->state.new = 0;
 566                                pvc = pvc->next;
 567                        }
 568                }
 569        } else {
 570                netif_dormant_on(dev);
 571                while (pvc) {           /* Deactivate all PVCs */
 572                        pvc_carrier(0, pvc);
 573                        pvc->state.exist = pvc->state.active = 0;
 574                        pvc->state.new = 0;
 575                        if (!state(hdlc)->settings.dce)
 576                                pvc->state.bandwidth = 0;
 577                        pvc = pvc->next;
 578                }
 579        }
 580}
 581
 582static void fr_timer(struct timer_list *t)
 583{
 584        struct frad_state *st = from_timer(st, t, timer);
 585        struct net_device *dev = st->dev;
 586        hdlc_device *hdlc = dev_to_hdlc(dev);
 587        int i, cnt = 0, reliable;
 588        u32 list;
 589
 590        if (state(hdlc)->settings.dce) {
 591                reliable = state(hdlc)->request &&
 592                        time_before(jiffies, state(hdlc)->last_poll +
 593                                    state(hdlc)->settings.t392 * HZ);
 594                state(hdlc)->request = 0;
 595        } else {
 596                state(hdlc)->last_errors <<= 1; /* Shift the list */
 597                if (state(hdlc)->request) {
 598                        if (state(hdlc)->reliable)
 599                                netdev_info(dev, "No LMI status reply received\n");
 600                        state(hdlc)->last_errors |= 1;
 601                }
 602
 603                list = state(hdlc)->last_errors;
 604                for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
 605                        cnt += (list & 1);      /* errors count */
 606
 607                reliable = (cnt < state(hdlc)->settings.n392);
 608        }
 609
 610        if (state(hdlc)->reliable != reliable) {
 611                netdev_info(dev, "Link %sreliable\n", reliable ? "" : "un");
 612                fr_set_link_state(reliable, dev);
 613        }
 614
 615        if (state(hdlc)->settings.dce) {
 616                state(hdlc)->timer.expires = jiffies +
 617                        state(hdlc)->settings.t392 * HZ;
 618        } else {
 619                if (state(hdlc)->n391cnt)
 620                        state(hdlc)->n391cnt--;
 621
 622                fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
 623
 624                state(hdlc)->last_poll = jiffies;
 625                state(hdlc)->request = 1;
 626                state(hdlc)->timer.expires = jiffies +
 627                        state(hdlc)->settings.t391 * HZ;
 628        }
 629
 630        add_timer(&state(hdlc)->timer);
 631}
 632
 633static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
 634{
 635        hdlc_device *hdlc = dev_to_hdlc(dev);
 636        struct pvc_device *pvc;
 637        u8 rxseq, txseq;
 638        int lmi = state(hdlc)->settings.lmi;
 639        int dce = state(hdlc)->settings.dce;
 640        int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
 641
 642        if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
 643                        LMI_CCITT_CISCO_LENGTH)) {
 644                netdev_info(dev, "Short LMI frame\n");
 645                return 1;
 646        }
 647
 648        if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
 649                             NLPID_CCITT_ANSI_LMI)) {
 650                netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
 651                return 1;
 652        }
 653
 654        if (skb->data[4] != LMI_CALLREF) {
 655                netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
 656                            skb->data[4]);
 657                return 1;
 658        }
 659
 660        if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
 661                netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
 662                            skb->data[5]);
 663                return 1;
 664        }
 665
 666        if (lmi == LMI_ANSI) {
 667                if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
 668                        netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
 669                                    skb->data[6]);
 670                        return 1;
 671                }
 672                i = 7;
 673        } else {
 674                i = 6;
 675        }
 676
 677        if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
 678                             LMI_ANSI_CISCO_REPTYPE)) {
 679                netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
 680                            skb->data[i]);
 681                return 1;
 682        }
 683
 684        if (skb->data[++i] != LMI_REPT_LEN) {
 685                netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
 686                            skb->data[i]);
 687                return 1;
 688        }
 689
 690        reptype = skb->data[++i];
 691        if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
 692                netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
 693                            reptype);
 694                return 1;
 695        }
 696
 697        if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
 698                               LMI_ANSI_CISCO_ALIVE)) {
 699                netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
 700                            skb->data[i]);
 701                return 1;
 702        }
 703
 704        if (skb->data[++i] != LMI_INTEG_LEN) {
 705                netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
 706                            skb->data[i]);
 707                return 1;
 708        }
 709        i++;
 710
 711        state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
 712        rxseq = skb->data[i++]; /* Should confirm our sequence */
 713
 714        txseq = state(hdlc)->txseq;
 715
 716        if (dce)
 717                state(hdlc)->last_poll = jiffies;
 718
 719        error = 0;
 720        if (!state(hdlc)->reliable)
 721                error = 1;
 722
 723        if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
 724                state(hdlc)->n391cnt = 0;
 725                error = 1;
 726        }
 727
 728        if (dce) {
 729                if (state(hdlc)->fullrep_sent && !error) {
 730/* Stop sending full report - the last one has been confirmed by DTE */
 731                        state(hdlc)->fullrep_sent = 0;
 732                        pvc = state(hdlc)->first_pvc;
 733                        while (pvc) {
 734                                if (pvc->state.new) {
 735                                        pvc->state.new = 0;
 736
 737/* Tell DTE that new PVC is now active */
 738                                        state(hdlc)->dce_changed = 1;
 739                                }
 740                                pvc = pvc->next;
 741                        }
 742                }
 743
 744                if (state(hdlc)->dce_changed) {
 745                        reptype = LMI_FULLREP;
 746                        state(hdlc)->fullrep_sent = 1;
 747                        state(hdlc)->dce_changed = 0;
 748                }
 749
 750                state(hdlc)->request = 1; /* got request */
 751                fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
 752                return 0;
 753        }
 754
 755        /* DTE */
 756
 757        state(hdlc)->request = 0; /* got response, no request pending */
 758
 759        if (error)
 760                return 0;
 761
 762        if (reptype != LMI_FULLREP)
 763                return 0;
 764
 765        pvc = state(hdlc)->first_pvc;
 766
 767        while (pvc) {
 768                pvc->state.deleted = 1;
 769                pvc = pvc->next;
 770        }
 771
 772        no_ram = 0;
 773        while (skb->len >= i + 2 + stat_len) {
 774                u16 dlci;
 775                u32 bw;
 776                unsigned int active, new;
 777
 778                if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
 779                                       LMI_ANSI_CISCO_PVCSTAT)) {
 780                        netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
 781                                    skb->data[i]);
 782                        return 1;
 783                }
 784
 785                if (skb->data[++i] != stat_len) {
 786                        netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
 787                                    skb->data[i]);
 788                        return 1;
 789                }
 790                i++;
 791
 792                new = !!(skb->data[i + 2] & 0x08);
 793                active = !!(skb->data[i + 2] & 0x02);
 794                if (lmi == LMI_CISCO) {
 795                        dlci = (skb->data[i] << 8) | skb->data[i + 1];
 796                        bw = (skb->data[i + 3] << 16) |
 797                                (skb->data[i + 4] << 8) |
 798                                (skb->data[i + 5]);
 799                } else {
 800                        dlci = ((skb->data[i] & 0x3F) << 4) |
 801                                ((skb->data[i + 1] & 0x78) >> 3);
 802                        bw = 0;
 803                }
 804
 805                pvc = add_pvc(dev, dlci);
 806
 807                if (!pvc && !no_ram) {
 808                        netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
 809                        no_ram = 1;
 810                }
 811
 812                if (pvc) {
 813                        pvc->state.exist = 1;
 814                        pvc->state.deleted = 0;
 815                        if (active != pvc->state.active ||
 816                            new != pvc->state.new ||
 817                            bw != pvc->state.bandwidth ||
 818                            !pvc->state.exist) {
 819                                pvc->state.new = new;
 820                                pvc->state.active = active;
 821                                pvc->state.bandwidth = bw;
 822                                pvc_carrier(active, pvc);
 823                                fr_log_dlci_active(pvc);
 824                        }
 825                }
 826
 827                i += stat_len;
 828        }
 829
 830        pvc = state(hdlc)->first_pvc;
 831
 832        while (pvc) {
 833                if (pvc->state.deleted && pvc->state.exist) {
 834                        pvc_carrier(0, pvc);
 835                        pvc->state.active = pvc->state.new = 0;
 836                        pvc->state.exist = 0;
 837                        pvc->state.bandwidth = 0;
 838                        fr_log_dlci_active(pvc);
 839                }
 840                pvc = pvc->next;
 841        }
 842
 843        /* Next full report after N391 polls */
 844        state(hdlc)->n391cnt = state(hdlc)->settings.n391;
 845
 846        return 0;
 847}
 848
 849static int fr_snap_parse(struct sk_buff *skb, struct pvc_device *pvc)
 850{
 851        /* OUI 00-00-00 indicates an Ethertype follows */
 852        if (skb->data[0] == 0x00 &&
 853            skb->data[1] == 0x00 &&
 854            skb->data[2] == 0x00) {
 855                if (!pvc->main)
 856                        return -1;
 857                skb->dev = pvc->main;
 858                skb->protocol = *(__be16 *)(skb->data + 3); /* Ethertype */
 859                skb_pull(skb, 5);
 860                skb_reset_mac_header(skb);
 861                return 0;
 862
 863        /* OUI 00-80-C2 stands for the 802.1 organization */
 864        } else if (skb->data[0] == 0x00 &&
 865                   skb->data[1] == 0x80 &&
 866                   skb->data[2] == 0xC2) {
 867                /* PID 00-07 stands for Ethernet frames without FCS */
 868                if (skb->data[3] == 0x00 &&
 869                    skb->data[4] == 0x07) {
 870                        if (!pvc->ether)
 871                                return -1;
 872                        skb_pull(skb, 5);
 873                        if (skb->len < ETH_HLEN)
 874                                return -1;
 875                        skb->protocol = eth_type_trans(skb, pvc->ether);
 876                        return 0;
 877
 878                /* PID unsupported */
 879                } else {
 880                        return -1;
 881                }
 882
 883        /* OUI unsupported */
 884        } else {
 885                return -1;
 886        }
 887}
 888
 889static int fr_rx(struct sk_buff *skb)
 890{
 891        struct net_device *frad = skb->dev;
 892        hdlc_device *hdlc = dev_to_hdlc(frad);
 893        struct fr_hdr *fh = (struct fr_hdr *)skb->data;
 894        u8 *data = skb->data;
 895        u16 dlci;
 896        struct pvc_device *pvc;
 897        struct net_device *dev;
 898
 899        if (skb->len < 4 || fh->ea1 || !fh->ea2 || data[2] != FR_UI)
 900                goto rx_error;
 901
 902        dlci = q922_to_dlci(skb->data);
 903
 904        if ((dlci == LMI_CCITT_ANSI_DLCI &&
 905             (state(hdlc)->settings.lmi == LMI_ANSI ||
 906              state(hdlc)->settings.lmi == LMI_CCITT)) ||
 907            (dlci == LMI_CISCO_DLCI &&
 908             state(hdlc)->settings.lmi == LMI_CISCO)) {
 909                if (fr_lmi_recv(frad, skb))
 910                        goto rx_error;
 911                dev_kfree_skb_any(skb);
 912                return NET_RX_SUCCESS;
 913        }
 914
 915        pvc = find_pvc(hdlc, dlci);
 916        if (!pvc) {
 917#ifdef DEBUG_PKT
 918                netdev_info(frad, "No PVC for received frame's DLCI %d\n",
 919                            dlci);
 920#endif
 921                goto rx_drop;
 922        }
 923
 924        if (pvc->state.fecn != fh->fecn) {
 925#ifdef DEBUG_ECN
 926                printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
 927                       dlci, fh->fecn ? "N" : "FF");
 928#endif
 929                pvc->state.fecn ^= 1;
 930        }
 931
 932        if (pvc->state.becn != fh->becn) {
 933#ifdef DEBUG_ECN
 934                printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
 935                       dlci, fh->becn ? "N" : "FF");
 936#endif
 937                pvc->state.becn ^= 1;
 938        }
 939
 940        skb = skb_share_check(skb, GFP_ATOMIC);
 941        if (!skb) {
 942                frad->stats.rx_dropped++;
 943                return NET_RX_DROP;
 944        }
 945
 946        if (data[3] == NLPID_IP) {
 947                if (!pvc->main)
 948                        goto rx_drop;
 949                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
 950                skb->dev = pvc->main;
 951                skb->protocol = htons(ETH_P_IP);
 952                skb_reset_mac_header(skb);
 953
 954        } else if (data[3] == NLPID_IPV6) {
 955                if (!pvc->main)
 956                        goto rx_drop;
 957                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
 958                skb->dev = pvc->main;
 959                skb->protocol = htons(ETH_P_IPV6);
 960                skb_reset_mac_header(skb);
 961
 962        } else if (data[3] == FR_PAD) {
 963                if (skb->len < 5)
 964                        goto rx_error;
 965                if (data[4] == NLPID_SNAP) { /* A SNAP header follows */
 966                        skb_pull(skb, 5);
 967                        if (skb->len < 5) /* Incomplete SNAP header */
 968                                goto rx_error;
 969                        if (fr_snap_parse(skb, pvc))
 970                                goto rx_drop;
 971                } else {
 972                        goto rx_drop;
 973                }
 974
 975        } else {
 976                netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
 977                            data[3], skb->len);
 978                goto rx_drop;
 979        }
 980
 981        dev = skb->dev;
 982        dev->stats.rx_packets++; /* PVC traffic */
 983        dev->stats.rx_bytes += skb->len;
 984        if (pvc->state.becn)
 985                dev->stats.rx_compressed++;
 986        netif_rx(skb);
 987        return NET_RX_SUCCESS;
 988
 989rx_error:
 990        frad->stats.rx_errors++; /* Mark error */
 991rx_drop:
 992        dev_kfree_skb_any(skb);
 993        return NET_RX_DROP;
 994}
 995
 996static void fr_start(struct net_device *dev)
 997{
 998        hdlc_device *hdlc = dev_to_hdlc(dev);
 999#ifdef DEBUG_LINK
1000        printk(KERN_DEBUG "fr_start\n");
1001#endif
1002        if (state(hdlc)->settings.lmi != LMI_NONE) {
1003                state(hdlc)->reliable = 0;
1004                state(hdlc)->dce_changed = 1;
1005                state(hdlc)->request = 0;
1006                state(hdlc)->fullrep_sent = 0;
1007                state(hdlc)->last_errors = 0xFFFFFFFF;
1008                state(hdlc)->n391cnt = 0;
1009                state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1010
1011                state(hdlc)->dev = dev;
1012                timer_setup(&state(hdlc)->timer, fr_timer, 0);
1013                /* First poll after 1 s */
1014                state(hdlc)->timer.expires = jiffies + HZ;
1015                add_timer(&state(hdlc)->timer);
1016        } else {
1017                fr_set_link_state(1, dev);
1018        }
1019}
1020
1021static void fr_stop(struct net_device *dev)
1022{
1023        hdlc_device *hdlc = dev_to_hdlc(dev);
1024#ifdef DEBUG_LINK
1025        printk(KERN_DEBUG "fr_stop\n");
1026#endif
1027        if (state(hdlc)->settings.lmi != LMI_NONE)
1028                del_timer_sync(&state(hdlc)->timer);
1029        fr_set_link_state(0, dev);
1030}
1031
1032static void fr_close(struct net_device *dev)
1033{
1034        hdlc_device *hdlc = dev_to_hdlc(dev);
1035        struct pvc_device *pvc = state(hdlc)->first_pvc;
1036
1037        while (pvc) {           /* Shutdown all PVCs for this FRAD */
1038                if (pvc->main)
1039                        dev_close(pvc->main);
1040                if (pvc->ether)
1041                        dev_close(pvc->ether);
1042                pvc = pvc->next;
1043        }
1044}
1045
1046static void pvc_setup(struct net_device *dev)
1047{
1048        dev->type = ARPHRD_DLCI;
1049        dev->flags = IFF_POINTOPOINT;
1050        dev->hard_header_len = 0;
1051        dev->addr_len = 2;
1052        netif_keep_dst(dev);
1053}
1054
1055static const struct net_device_ops pvc_ops = {
1056        .ndo_open       = pvc_open,
1057        .ndo_stop       = pvc_close,
1058        .ndo_start_xmit = pvc_xmit,
1059        .ndo_siocwandev = pvc_ioctl,
1060};
1061
1062static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1063{
1064        hdlc_device *hdlc = dev_to_hdlc(frad);
1065        struct pvc_device *pvc;
1066        struct net_device *dev;
1067        int used;
1068
1069        pvc = add_pvc(frad, dlci);
1070        if (!pvc) {
1071                netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1072                return -ENOBUFS;
1073        }
1074
1075        if (*get_dev_p(pvc, type))
1076                return -EEXIST;
1077
1078        used = pvc_is_used(pvc);
1079
1080        if (type == ARPHRD_ETHER)
1081                dev = alloc_netdev(0, "pvceth%d", NET_NAME_UNKNOWN,
1082                                   ether_setup);
1083        else
1084                dev = alloc_netdev(0, "pvc%d", NET_NAME_UNKNOWN, pvc_setup);
1085
1086        if (!dev) {
1087                netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1088                delete_unused_pvcs(hdlc);
1089                return -ENOBUFS;
1090        }
1091
1092        if (type == ARPHRD_ETHER) {
1093                dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1094                eth_hw_addr_random(dev);
1095        } else {
1096                __be16 addr = htons(dlci);
1097
1098                dev_addr_set(dev, (u8 *)&addr);
1099                dlci_to_q922(dev->broadcast, dlci);
1100        }
1101        dev->netdev_ops = &pvc_ops;
1102        dev->mtu = HDLC_MAX_MTU;
1103        dev->min_mtu = 68;
1104        dev->max_mtu = HDLC_MAX_MTU;
1105        dev->needed_headroom = 10;
1106        dev->priv_flags |= IFF_NO_QUEUE;
1107        dev->ml_priv = pvc;
1108
1109        if (register_netdevice(dev) != 0) {
1110                free_netdev(dev);
1111                delete_unused_pvcs(hdlc);
1112                return -EIO;
1113        }
1114
1115        dev->needs_free_netdev = true;
1116        *get_dev_p(pvc, type) = dev;
1117        if (!used) {
1118                state(hdlc)->dce_changed = 1;
1119                state(hdlc)->dce_pvc_count++;
1120        }
1121        return 0;
1122}
1123
1124static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1125{
1126        struct pvc_device *pvc;
1127        struct net_device *dev;
1128
1129        pvc = find_pvc(hdlc, dlci);
1130        if (!pvc)
1131                return -ENOENT;
1132
1133        dev = *get_dev_p(pvc, type);
1134        if (!dev)
1135                return -ENOENT;
1136
1137        if (dev->flags & IFF_UP)
1138                return -EBUSY;          /* PVC in use */
1139
1140        unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1141        *get_dev_p(pvc, type) = NULL;
1142
1143        if (!pvc_is_used(pvc)) {
1144                state(hdlc)->dce_pvc_count--;
1145                state(hdlc)->dce_changed = 1;
1146        }
1147        delete_unused_pvcs(hdlc);
1148        return 0;
1149}
1150
1151static void fr_destroy(struct net_device *frad)
1152{
1153        hdlc_device *hdlc = dev_to_hdlc(frad);
1154        struct pvc_device *pvc = state(hdlc)->first_pvc;
1155
1156        state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1157        state(hdlc)->dce_pvc_count = 0;
1158        state(hdlc)->dce_changed = 1;
1159
1160        while (pvc) {
1161                struct pvc_device *next = pvc->next;
1162                /* destructors will free_netdev() main and ether */
1163                if (pvc->main)
1164                        unregister_netdevice(pvc->main);
1165
1166                if (pvc->ether)
1167                        unregister_netdevice(pvc->ether);
1168
1169                kfree(pvc);
1170                pvc = next;
1171        }
1172}
1173
1174static struct hdlc_proto proto = {
1175        .close          = fr_close,
1176        .start          = fr_start,
1177        .stop           = fr_stop,
1178        .detach         = fr_destroy,
1179        .ioctl          = fr_ioctl,
1180        .netif_rx       = fr_rx,
1181        .module         = THIS_MODULE,
1182};
1183
1184static int fr_ioctl(struct net_device *dev, struct if_settings *ifs)
1185{
1186        fr_proto __user *fr_s = ifs->ifs_ifsu.fr;
1187        const size_t size = sizeof(fr_proto);
1188        fr_proto new_settings;
1189        hdlc_device *hdlc = dev_to_hdlc(dev);
1190        fr_proto_pvc pvc;
1191        int result;
1192
1193        switch (ifs->type) {
1194        case IF_GET_PROTO:
1195                if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1196                        return -EINVAL;
1197                ifs->type = IF_PROTO_FR;
1198                if (ifs->size < size) {
1199                        ifs->size = size; /* data size wanted */
1200                        return -ENOBUFS;
1201                }
1202                if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1203                        return -EFAULT;
1204                return 0;
1205
1206        case IF_PROTO_FR:
1207                if (!capable(CAP_NET_ADMIN))
1208                        return -EPERM;
1209
1210                if (dev->flags & IFF_UP)
1211                        return -EBUSY;
1212
1213                if (copy_from_user(&new_settings, fr_s, size))
1214                        return -EFAULT;
1215
1216                if (new_settings.lmi == LMI_DEFAULT)
1217                        new_settings.lmi = LMI_ANSI;
1218
1219                if ((new_settings.lmi != LMI_NONE &&
1220                     new_settings.lmi != LMI_ANSI &&
1221                     new_settings.lmi != LMI_CCITT &&
1222                     new_settings.lmi != LMI_CISCO) ||
1223                    new_settings.t391 < 1 ||
1224                    new_settings.t392 < 2 ||
1225                    new_settings.n391 < 1 ||
1226                    new_settings.n392 < 1 ||
1227                    new_settings.n393 < new_settings.n392 ||
1228                    new_settings.n393 > 32 ||
1229                    (new_settings.dce != 0 &&
1230                     new_settings.dce != 1))
1231                        return -EINVAL;
1232
1233                result = hdlc->attach(dev, ENCODING_NRZ,
1234                                      PARITY_CRC16_PR1_CCITT);
1235                if (result)
1236                        return result;
1237
1238                if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1239                        result = attach_hdlc_protocol(dev, &proto,
1240                                                      sizeof(struct frad_state));
1241                        if (result)
1242                                return result;
1243                        state(hdlc)->first_pvc = NULL;
1244                        state(hdlc)->dce_pvc_count = 0;
1245                }
1246                memcpy(&state(hdlc)->settings, &new_settings, size);
1247                dev->type = ARPHRD_FRAD;
1248                call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1249                return 0;
1250
1251        case IF_PROTO_FR_ADD_PVC:
1252        case IF_PROTO_FR_DEL_PVC:
1253        case IF_PROTO_FR_ADD_ETH_PVC:
1254        case IF_PROTO_FR_DEL_ETH_PVC:
1255                if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1256                        return -EINVAL;
1257
1258                if (!capable(CAP_NET_ADMIN))
1259                        return -EPERM;
1260
1261                if (copy_from_user(&pvc, ifs->ifs_ifsu.fr_pvc,
1262                                   sizeof(fr_proto_pvc)))
1263                        return -EFAULT;
1264
1265                if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1266                        return -EINVAL; /* Only 10 bits, DLCI 0 reserved */
1267
1268                if (ifs->type == IF_PROTO_FR_ADD_ETH_PVC ||
1269                    ifs->type == IF_PROTO_FR_DEL_ETH_PVC)
1270                        result = ARPHRD_ETHER; /* bridged Ethernet device */
1271                else
1272                        result = ARPHRD_DLCI;
1273
1274                if (ifs->type == IF_PROTO_FR_ADD_PVC ||
1275                    ifs->type == IF_PROTO_FR_ADD_ETH_PVC)
1276                        return fr_add_pvc(dev, pvc.dlci, result);
1277                else
1278                        return fr_del_pvc(hdlc, pvc.dlci, result);
1279        }
1280
1281        return -EINVAL;
1282}
1283
1284static int __init hdlc_fr_init(void)
1285{
1286        register_hdlc_protocol(&proto);
1287        return 0;
1288}
1289
1290static void __exit hdlc_fr_exit(void)
1291{
1292        unregister_hdlc_protocol(&proto);
1293}
1294
1295module_init(hdlc_fr_init);
1296module_exit(hdlc_fr_exit);
1297
1298MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1299MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1300MODULE_LICENSE("GPL v2");
1301