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
  64#define LMI_CCITT_ANSI_DLCI        0 /* LMI DLCI */
  65#define LMI_CISCO_DLCI          1023
  66
  67#define LMI_CALLREF             0x00 /* Call Reference */
  68#define LMI_ANSI_LOCKSHIFT      0x95 /* ANSI locking shift */
  69#define LMI_ANSI_CISCO_REPTYPE  0x01 /* report type */
  70#define LMI_CCITT_REPTYPE       0x51
  71#define LMI_ANSI_CISCO_ALIVE    0x03 /* keep alive */
  72#define LMI_CCITT_ALIVE         0x53
  73#define LMI_ANSI_CISCO_PVCSTAT  0x07 /* PVC status */
  74#define LMI_CCITT_PVCSTAT       0x57
  75
  76#define LMI_FULLREP             0x00 /* full report  */
  77#define LMI_INTEGRITY           0x01 /* link integrity report */
  78#define LMI_SINGLE              0x02 /* single PVC report */
  79
  80#define LMI_STATUS_ENQUIRY      0x75
  81#define LMI_STATUS              0x7D /* reply */
  82
  83#define LMI_REPT_LEN               1 /* report type element length */
  84#define LMI_INTEG_LEN              2 /* link integrity element length */
  85
  86#define LMI_CCITT_CISCO_LENGTH    13 /* LMI frame lengths */
  87#define LMI_ANSI_LENGTH           14
  88
  89
  90struct fr_hdr {
  91#if defined(__LITTLE_ENDIAN_BITFIELD)
  92        unsigned ea1:   1;
  93        unsigned cr:    1;
  94        unsigned dlcih: 6;
  95
  96        unsigned ea2:   1;
  97        unsigned de:    1;
  98        unsigned becn:  1;
  99        unsigned fecn:  1;
 100        unsigned dlcil: 4;
 101#else
 102        unsigned dlcih: 6;
 103        unsigned cr:    1;
 104        unsigned ea1:   1;
 105
 106        unsigned dlcil: 4;
 107        unsigned fecn:  1;
 108        unsigned becn:  1;
 109        unsigned de:    1;
 110        unsigned ea2:   1;
 111#endif
 112} __packed;
 113
 114
 115struct pvc_device {
 116        struct net_device *frad;
 117        struct net_device *main;
 118        struct net_device *ether;       /* bridged Ethernet interface   */
 119        struct pvc_device *next;        /* Sorted in ascending DLCI order */
 120        int dlci;
 121        int open_count;
 122
 123        struct {
 124                unsigned int new: 1;
 125                unsigned int active: 1;
 126                unsigned int exist: 1;
 127                unsigned int deleted: 1;
 128                unsigned int fecn: 1;
 129                unsigned int becn: 1;
 130                unsigned int bandwidth; /* Cisco LMI reporting only */
 131        }state;
 132};
 133
 134struct frad_state {
 135        fr_proto settings;
 136        struct pvc_device *first_pvc;
 137        int dce_pvc_count;
 138
 139        struct timer_list timer;
 140        struct net_device *dev;
 141        unsigned long last_poll;
 142        int reliable;
 143        int dce_changed;
 144        int request;
 145        int fullrep_sent;
 146        u32 last_errors; /* last errors bit list */
 147        u8 n391cnt;
 148        u8 txseq; /* TX sequence number */
 149        u8 rxseq; /* RX sequence number */
 150};
 151
 152
 153static int fr_ioctl(struct net_device *dev, struct ifreq *ifr);
 154
 155
 156static inline u16 q922_to_dlci(u8 *hdr)
 157{
 158        return ((hdr[0] & 0xFC) << 2) | ((hdr[1] & 0xF0) >> 4);
 159}
 160
 161
 162static inline void dlci_to_q922(u8 *hdr, u16 dlci)
 163{
 164        hdr[0] = (dlci >> 2) & 0xFC;
 165        hdr[1] = ((dlci << 4) & 0xF0) | 0x01;
 166}
 167
 168
 169static inline struct frad_state* state(hdlc_device *hdlc)
 170{
 171        return(struct frad_state *)(hdlc->state);
 172}
 173
 174
 175static inline struct pvc_device *find_pvc(hdlc_device *hdlc, u16 dlci)
 176{
 177        struct pvc_device *pvc = state(hdlc)->first_pvc;
 178
 179        while (pvc) {
 180                if (pvc->dlci == dlci)
 181                        return pvc;
 182                if (pvc->dlci > dlci)
 183                        return NULL; /* the list is sorted */
 184                pvc = pvc->next;
 185        }
 186
 187        return NULL;
 188}
 189
 190
 191static struct pvc_device *add_pvc(struct net_device *dev, u16 dlci)
 192{
 193        hdlc_device *hdlc = dev_to_hdlc(dev);
 194        struct pvc_device *pvc, **pvc_p = &state(hdlc)->first_pvc;
 195
 196        while (*pvc_p) {
 197                if ((*pvc_p)->dlci == dlci)
 198                        return *pvc_p;
 199                if ((*pvc_p)->dlci > dlci)
 200                        break;  /* the list is sorted */
 201                pvc_p = &(*pvc_p)->next;
 202        }
 203
 204        pvc = kzalloc(sizeof(*pvc), GFP_ATOMIC);
 205#ifdef DEBUG_PVC
 206        printk(KERN_DEBUG "add_pvc: allocated pvc %p, frad %p\n", pvc, dev);
 207#endif
 208        if (!pvc)
 209                return NULL;
 210
 211        pvc->dlci = dlci;
 212        pvc->frad = dev;
 213        pvc->next = *pvc_p;     /* Put it in the chain */
 214        *pvc_p = pvc;
 215        return pvc;
 216}
 217
 218
 219static inline int pvc_is_used(struct pvc_device *pvc)
 220{
 221        return pvc->main || pvc->ether;
 222}
 223
 224
 225static inline void pvc_carrier(int on, struct pvc_device *pvc)
 226{
 227        if (on) {
 228                if (pvc->main)
 229                        if (!netif_carrier_ok(pvc->main))
 230                                netif_carrier_on(pvc->main);
 231                if (pvc->ether)
 232                        if (!netif_carrier_ok(pvc->ether))
 233                                netif_carrier_on(pvc->ether);
 234        } else {
 235                if (pvc->main)
 236                        if (netif_carrier_ok(pvc->main))
 237                                netif_carrier_off(pvc->main);
 238                if (pvc->ether)
 239                        if (netif_carrier_ok(pvc->ether))
 240                                netif_carrier_off(pvc->ether);
 241        }
 242}
 243
 244
 245static inline void delete_unused_pvcs(hdlc_device *hdlc)
 246{
 247        struct pvc_device **pvc_p = &state(hdlc)->first_pvc;
 248
 249        while (*pvc_p) {
 250                if (!pvc_is_used(*pvc_p)) {
 251                        struct pvc_device *pvc = *pvc_p;
 252#ifdef DEBUG_PVC
 253                        printk(KERN_DEBUG "freeing unused pvc: %p\n", pvc);
 254#endif
 255                        *pvc_p = pvc->next;
 256                        kfree(pvc);
 257                        continue;
 258                }
 259                pvc_p = &(*pvc_p)->next;
 260        }
 261}
 262
 263
 264static inline struct net_device **get_dev_p(struct pvc_device *pvc,
 265                                            int type)
 266{
 267        if (type == ARPHRD_ETHER)
 268                return &pvc->ether;
 269        else
 270                return &pvc->main;
 271}
 272
 273
 274static int fr_hard_header(struct sk_buff **skb_p, u16 dlci)
 275{
 276        u16 head_len;
 277        struct sk_buff *skb = *skb_p;
 278
 279        switch (skb->protocol) {
 280        case cpu_to_be16(NLPID_CCITT_ANSI_LMI):
 281                head_len = 4;
 282                skb_push(skb, head_len);
 283                skb->data[3] = NLPID_CCITT_ANSI_LMI;
 284                break;
 285
 286        case cpu_to_be16(NLPID_CISCO_LMI):
 287                head_len = 4;
 288                skb_push(skb, head_len);
 289                skb->data[3] = NLPID_CISCO_LMI;
 290                break;
 291
 292        case cpu_to_be16(ETH_P_IP):
 293                head_len = 4;
 294                skb_push(skb, head_len);
 295                skb->data[3] = NLPID_IP;
 296                break;
 297
 298        case cpu_to_be16(ETH_P_IPV6):
 299                head_len = 4;
 300                skb_push(skb, head_len);
 301                skb->data[3] = NLPID_IPV6;
 302                break;
 303
 304        case cpu_to_be16(ETH_P_802_3):
 305                head_len = 10;
 306                if (skb_headroom(skb) < head_len) {
 307                        struct sk_buff *skb2 = skb_realloc_headroom(skb,
 308                                                                    head_len);
 309                        if (!skb2)
 310                                return -ENOBUFS;
 311                        dev_kfree_skb(skb);
 312                        skb = *skb_p = skb2;
 313                }
 314                skb_push(skb, head_len);
 315                skb->data[3] = FR_PAD;
 316                skb->data[4] = NLPID_SNAP;
 317                skb->data[5] = FR_PAD;
 318                skb->data[6] = 0x80;
 319                skb->data[7] = 0xC2;
 320                skb->data[8] = 0x00;
 321                skb->data[9] = 0x07; /* bridged Ethernet frame w/out FCS */
 322                break;
 323
 324        default:
 325                head_len = 10;
 326                skb_push(skb, head_len);
 327                skb->data[3] = FR_PAD;
 328                skb->data[4] = NLPID_SNAP;
 329                skb->data[5] = FR_PAD;
 330                skb->data[6] = FR_PAD;
 331                skb->data[7] = FR_PAD;
 332                *(__be16*)(skb->data + 8) = skb->protocol;
 333        }
 334
 335        dlci_to_q922(skb->data, dlci);
 336        skb->data[2] = FR_UI;
 337        return 0;
 338}
 339
 340
 341
 342static int pvc_open(struct net_device *dev)
 343{
 344        struct pvc_device *pvc = dev->ml_priv;
 345
 346        if ((pvc->frad->flags & IFF_UP) == 0)
 347                return -EIO;  /* Frad must be UP in order to activate PVC */
 348
 349        if (pvc->open_count++ == 0) {
 350                hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
 351                if (state(hdlc)->settings.lmi == LMI_NONE)
 352                        pvc->state.active = netif_carrier_ok(pvc->frad);
 353
 354                pvc_carrier(pvc->state.active, pvc);
 355                state(hdlc)->dce_changed = 1;
 356        }
 357        return 0;
 358}
 359
 360
 361
 362static int pvc_close(struct net_device *dev)
 363{
 364        struct pvc_device *pvc = dev->ml_priv;
 365
 366        if (--pvc->open_count == 0) {
 367                hdlc_device *hdlc = dev_to_hdlc(pvc->frad);
 368                if (state(hdlc)->settings.lmi == LMI_NONE)
 369                        pvc->state.active = 0;
 370
 371                if (state(hdlc)->settings.dce) {
 372                        state(hdlc)->dce_changed = 1;
 373                        pvc->state.active = 0;
 374                }
 375        }
 376        return 0;
 377}
 378
 379
 380
 381static int pvc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 382{
 383        struct pvc_device *pvc = dev->ml_priv;
 384        fr_proto_pvc_info info;
 385
 386        if (ifr->ifr_settings.type == IF_GET_PROTO) {
 387                if (dev->type == ARPHRD_ETHER)
 388                        ifr->ifr_settings.type = IF_PROTO_FR_ETH_PVC;
 389                else
 390                        ifr->ifr_settings.type = IF_PROTO_FR_PVC;
 391
 392                if (ifr->ifr_settings.size < sizeof(info)) {
 393                        /* data size wanted */
 394                        ifr->ifr_settings.size = sizeof(info);
 395                        return -ENOBUFS;
 396                }
 397
 398                info.dlci = pvc->dlci;
 399                memcpy(info.master, pvc->frad->name, IFNAMSIZ);
 400                if (copy_to_user(ifr->ifr_settings.ifs_ifsu.fr_pvc_info,
 401                                 &info, sizeof(info)))
 402                        return -EFAULT;
 403                return 0;
 404        }
 405
 406        return -EINVAL;
 407}
 408
 409static netdev_tx_t pvc_xmit(struct sk_buff *skb, struct net_device *dev)
 410{
 411        struct pvc_device *pvc = dev->ml_priv;
 412
 413        if (pvc->state.active) {
 414                if (dev->type == ARPHRD_ETHER) {
 415                        int pad = ETH_ZLEN - skb->len;
 416                        if (pad > 0) { /* Pad the frame with zeros */
 417                                int len = skb->len;
 418                                if (skb_tailroom(skb) < pad)
 419                                        if (pskb_expand_head(skb, 0, pad,
 420                                                             GFP_ATOMIC)) {
 421                                                dev->stats.tx_dropped++;
 422                                                dev_kfree_skb(skb);
 423                                                return NETDEV_TX_OK;
 424                                        }
 425                                skb_put(skb, pad);
 426                                memset(skb->data + len, 0, pad);
 427                        }
 428                        skb->protocol = cpu_to_be16(ETH_P_802_3);
 429                }
 430                if (!fr_hard_header(&skb, pvc->dlci)) {
 431                        dev->stats.tx_bytes += skb->len;
 432                        dev->stats.tx_packets++;
 433                        if (pvc->state.fecn) /* TX Congestion counter */
 434                                dev->stats.tx_compressed++;
 435                        skb->dev = pvc->frad;
 436                        dev_queue_xmit(skb);
 437                        return NETDEV_TX_OK;
 438                }
 439        }
 440
 441        dev->stats.tx_dropped++;
 442        dev_kfree_skb(skb);
 443        return NETDEV_TX_OK;
 444}
 445
 446static inline void fr_log_dlci_active(struct pvc_device *pvc)
 447{
 448        netdev_info(pvc->frad, "DLCI %d [%s%s%s]%s %s\n",
 449                    pvc->dlci,
 450                    pvc->main ? pvc->main->name : "",
 451                    pvc->main && pvc->ether ? " " : "",
 452                    pvc->ether ? pvc->ether->name : "",
 453                    pvc->state.new ? " new" : "",
 454                    !pvc->state.exist ? "deleted" :
 455                    pvc->state.active ? "active" : "inactive");
 456}
 457
 458
 459
 460static inline u8 fr_lmi_nextseq(u8 x)
 461{
 462        x++;
 463        return x ? x : 1;
 464}
 465
 466
 467static void fr_lmi_send(struct net_device *dev, int fullrep)
 468{
 469        hdlc_device *hdlc = dev_to_hdlc(dev);
 470        struct sk_buff *skb;
 471        struct pvc_device *pvc = state(hdlc)->first_pvc;
 472        int lmi = state(hdlc)->settings.lmi;
 473        int dce = state(hdlc)->settings.dce;
 474        int len = lmi == LMI_ANSI ? LMI_ANSI_LENGTH : LMI_CCITT_CISCO_LENGTH;
 475        int stat_len = (lmi == LMI_CISCO) ? 6 : 3;
 476        u8 *data;
 477        int i = 0;
 478
 479        if (dce && fullrep) {
 480                len += state(hdlc)->dce_pvc_count * (2 + stat_len);
 481                if (len > HDLC_MAX_MRU) {
 482                        netdev_warn(dev, "Too many PVCs while sending LMI full report\n");
 483                        return;
 484                }
 485        }
 486
 487        skb = dev_alloc_skb(len);
 488        if (!skb) {
 489                netdev_warn(dev, "Memory squeeze on fr_lmi_send()\n");
 490                return;
 491        }
 492        memset(skb->data, 0, len);
 493        skb_reserve(skb, 4);
 494        if (lmi == LMI_CISCO) {
 495                skb->protocol = cpu_to_be16(NLPID_CISCO_LMI);
 496                fr_hard_header(&skb, LMI_CISCO_DLCI);
 497        } else {
 498                skb->protocol = cpu_to_be16(NLPID_CCITT_ANSI_LMI);
 499                fr_hard_header(&skb, LMI_CCITT_ANSI_DLCI);
 500        }
 501        data = skb_tail_pointer(skb);
 502        data[i++] = LMI_CALLREF;
 503        data[i++] = dce ? LMI_STATUS : LMI_STATUS_ENQUIRY;
 504        if (lmi == LMI_ANSI)
 505                data[i++] = LMI_ANSI_LOCKSHIFT;
 506        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
 507                LMI_ANSI_CISCO_REPTYPE;
 508        data[i++] = LMI_REPT_LEN;
 509        data[i++] = fullrep ? LMI_FULLREP : LMI_INTEGRITY;
 510        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_ALIVE : LMI_ANSI_CISCO_ALIVE;
 511        data[i++] = LMI_INTEG_LEN;
 512        data[i++] = state(hdlc)->txseq =
 513                fr_lmi_nextseq(state(hdlc)->txseq);
 514        data[i++] = state(hdlc)->rxseq;
 515
 516        if (dce && fullrep) {
 517                while (pvc) {
 518                        data[i++] = lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
 519                                LMI_ANSI_CISCO_PVCSTAT;
 520                        data[i++] = stat_len;
 521
 522                        /* LMI start/restart */
 523                        if (state(hdlc)->reliable && !pvc->state.exist) {
 524                                pvc->state.exist = pvc->state.new = 1;
 525                                fr_log_dlci_active(pvc);
 526                        }
 527
 528                        /* ifconfig PVC up */
 529                        if (pvc->open_count && !pvc->state.active &&
 530                            pvc->state.exist && !pvc->state.new) {
 531                                pvc_carrier(1, pvc);
 532                                pvc->state.active = 1;
 533                                fr_log_dlci_active(pvc);
 534                        }
 535
 536                        if (lmi == LMI_CISCO) {
 537                                data[i] = pvc->dlci >> 8;
 538                                data[i + 1] = pvc->dlci & 0xFF;
 539                        } else {
 540                                data[i] = (pvc->dlci >> 4) & 0x3F;
 541                                data[i + 1] = ((pvc->dlci << 3) & 0x78) | 0x80;
 542                                data[i + 2] = 0x80;
 543                        }
 544
 545                        if (pvc->state.new)
 546                                data[i + 2] |= 0x08;
 547                        else if (pvc->state.active)
 548                                data[i + 2] |= 0x02;
 549
 550                        i += stat_len;
 551                        pvc = pvc->next;
 552                }
 553        }
 554
 555        skb_put(skb, i);
 556        skb->priority = TC_PRIO_CONTROL;
 557        skb->dev = dev;
 558        skb_reset_network_header(skb);
 559
 560        dev_queue_xmit(skb);
 561}
 562
 563
 564
 565static void fr_set_link_state(int reliable, struct net_device *dev)
 566{
 567        hdlc_device *hdlc = dev_to_hdlc(dev);
 568        struct pvc_device *pvc = state(hdlc)->first_pvc;
 569
 570        state(hdlc)->reliable = reliable;
 571        if (reliable) {
 572                netif_dormant_off(dev);
 573                state(hdlc)->n391cnt = 0; /* Request full status */
 574                state(hdlc)->dce_changed = 1;
 575
 576                if (state(hdlc)->settings.lmi == LMI_NONE) {
 577                        while (pvc) {   /* Activate all PVCs */
 578                                pvc_carrier(1, pvc);
 579                                pvc->state.exist = pvc->state.active = 1;
 580                                pvc->state.new = 0;
 581                                pvc = pvc->next;
 582                        }
 583                }
 584        } else {
 585                netif_dormant_on(dev);
 586                while (pvc) {           /* Deactivate all PVCs */
 587                        pvc_carrier(0, pvc);
 588                        pvc->state.exist = pvc->state.active = 0;
 589                        pvc->state.new = 0;
 590                        if (!state(hdlc)->settings.dce)
 591                                pvc->state.bandwidth = 0;
 592                        pvc = pvc->next;
 593                }
 594        }
 595}
 596
 597
 598static void fr_timer(struct timer_list *t)
 599{
 600        struct frad_state *st = from_timer(st, t, timer);
 601        struct net_device *dev = st->dev;
 602        hdlc_device *hdlc = dev_to_hdlc(dev);
 603        int i, cnt = 0, reliable;
 604        u32 list;
 605
 606        if (state(hdlc)->settings.dce) {
 607                reliable = state(hdlc)->request &&
 608                        time_before(jiffies, state(hdlc)->last_poll +
 609                                    state(hdlc)->settings.t392 * HZ);
 610                state(hdlc)->request = 0;
 611        } else {
 612                state(hdlc)->last_errors <<= 1; /* Shift the list */
 613                if (state(hdlc)->request) {
 614                        if (state(hdlc)->reliable)
 615                                netdev_info(dev, "No LMI status reply received\n");
 616                        state(hdlc)->last_errors |= 1;
 617                }
 618
 619                list = state(hdlc)->last_errors;
 620                for (i = 0; i < state(hdlc)->settings.n393; i++, list >>= 1)
 621                        cnt += (list & 1);      /* errors count */
 622
 623                reliable = (cnt < state(hdlc)->settings.n392);
 624        }
 625
 626        if (state(hdlc)->reliable != reliable) {
 627                netdev_info(dev, "Link %sreliable\n", reliable ? "" : "un");
 628                fr_set_link_state(reliable, dev);
 629        }
 630
 631        if (state(hdlc)->settings.dce)
 632                state(hdlc)->timer.expires = jiffies +
 633                        state(hdlc)->settings.t392 * HZ;
 634        else {
 635                if (state(hdlc)->n391cnt)
 636                        state(hdlc)->n391cnt--;
 637
 638                fr_lmi_send(dev, state(hdlc)->n391cnt == 0);
 639
 640                state(hdlc)->last_poll = jiffies;
 641                state(hdlc)->request = 1;
 642                state(hdlc)->timer.expires = jiffies +
 643                        state(hdlc)->settings.t391 * HZ;
 644        }
 645
 646        add_timer(&state(hdlc)->timer);
 647}
 648
 649
 650static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb)
 651{
 652        hdlc_device *hdlc = dev_to_hdlc(dev);
 653        struct pvc_device *pvc;
 654        u8 rxseq, txseq;
 655        int lmi = state(hdlc)->settings.lmi;
 656        int dce = state(hdlc)->settings.dce;
 657        int stat_len = (lmi == LMI_CISCO) ? 6 : 3, reptype, error, no_ram, i;
 658
 659        if (skb->len < (lmi == LMI_ANSI ? LMI_ANSI_LENGTH :
 660                        LMI_CCITT_CISCO_LENGTH)) {
 661                netdev_info(dev, "Short LMI frame\n");
 662                return 1;
 663        }
 664
 665        if (skb->data[3] != (lmi == LMI_CISCO ? NLPID_CISCO_LMI :
 666                             NLPID_CCITT_ANSI_LMI)) {
 667                netdev_info(dev, "Received non-LMI frame with LMI DLCI\n");
 668                return 1;
 669        }
 670
 671        if (skb->data[4] != LMI_CALLREF) {
 672                netdev_info(dev, "Invalid LMI Call reference (0x%02X)\n",
 673                            skb->data[4]);
 674                return 1;
 675        }
 676
 677        if (skb->data[5] != (dce ? LMI_STATUS_ENQUIRY : LMI_STATUS)) {
 678                netdev_info(dev, "Invalid LMI Message type (0x%02X)\n",
 679                            skb->data[5]);
 680                return 1;
 681        }
 682
 683        if (lmi == LMI_ANSI) {
 684                if (skb->data[6] != LMI_ANSI_LOCKSHIFT) {
 685                        netdev_info(dev, "Not ANSI locking shift in LMI message (0x%02X)\n",
 686                                    skb->data[6]);
 687                        return 1;
 688                }
 689                i = 7;
 690        } else
 691                i = 6;
 692
 693        if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_REPTYPE :
 694                             LMI_ANSI_CISCO_REPTYPE)) {
 695                netdev_info(dev, "Not an LMI Report type IE (0x%02X)\n",
 696                            skb->data[i]);
 697                return 1;
 698        }
 699
 700        if (skb->data[++i] != LMI_REPT_LEN) {
 701                netdev_info(dev, "Invalid LMI Report type IE length (%u)\n",
 702                            skb->data[i]);
 703                return 1;
 704        }
 705
 706        reptype = skb->data[++i];
 707        if (reptype != LMI_INTEGRITY && reptype != LMI_FULLREP) {
 708                netdev_info(dev, "Unsupported LMI Report type (0x%02X)\n",
 709                            reptype);
 710                return 1;
 711        }
 712
 713        if (skb->data[++i] != (lmi == LMI_CCITT ? LMI_CCITT_ALIVE :
 714                               LMI_ANSI_CISCO_ALIVE)) {
 715                netdev_info(dev, "Not an LMI Link integrity verification IE (0x%02X)\n",
 716                            skb->data[i]);
 717                return 1;
 718        }
 719
 720        if (skb->data[++i] != LMI_INTEG_LEN) {
 721                netdev_info(dev, "Invalid LMI Link integrity verification IE length (%u)\n",
 722                            skb->data[i]);
 723                return 1;
 724        }
 725        i++;
 726
 727        state(hdlc)->rxseq = skb->data[i++]; /* TX sequence from peer */
 728        rxseq = skb->data[i++]; /* Should confirm our sequence */
 729
 730        txseq = state(hdlc)->txseq;
 731
 732        if (dce)
 733                state(hdlc)->last_poll = jiffies;
 734
 735        error = 0;
 736        if (!state(hdlc)->reliable)
 737                error = 1;
 738
 739        if (rxseq == 0 || rxseq != txseq) { /* Ask for full report next time */
 740                state(hdlc)->n391cnt = 0;
 741                error = 1;
 742        }
 743
 744        if (dce) {
 745                if (state(hdlc)->fullrep_sent && !error) {
 746/* Stop sending full report - the last one has been confirmed by DTE */
 747                        state(hdlc)->fullrep_sent = 0;
 748                        pvc = state(hdlc)->first_pvc;
 749                        while (pvc) {
 750                                if (pvc->state.new) {
 751                                        pvc->state.new = 0;
 752
 753/* Tell DTE that new PVC is now active */
 754                                        state(hdlc)->dce_changed = 1;
 755                                }
 756                                pvc = pvc->next;
 757                        }
 758                }
 759
 760                if (state(hdlc)->dce_changed) {
 761                        reptype = LMI_FULLREP;
 762                        state(hdlc)->fullrep_sent = 1;
 763                        state(hdlc)->dce_changed = 0;
 764                }
 765
 766                state(hdlc)->request = 1; /* got request */
 767                fr_lmi_send(dev, reptype == LMI_FULLREP ? 1 : 0);
 768                return 0;
 769        }
 770
 771        /* DTE */
 772
 773        state(hdlc)->request = 0; /* got response, no request pending */
 774
 775        if (error)
 776                return 0;
 777
 778        if (reptype != LMI_FULLREP)
 779                return 0;
 780
 781        pvc = state(hdlc)->first_pvc;
 782
 783        while (pvc) {
 784                pvc->state.deleted = 1;
 785                pvc = pvc->next;
 786        }
 787
 788        no_ram = 0;
 789        while (skb->len >= i + 2 + stat_len) {
 790                u16 dlci;
 791                u32 bw;
 792                unsigned int active, new;
 793
 794                if (skb->data[i] != (lmi == LMI_CCITT ? LMI_CCITT_PVCSTAT :
 795                                       LMI_ANSI_CISCO_PVCSTAT)) {
 796                        netdev_info(dev, "Not an LMI PVC status IE (0x%02X)\n",
 797                                    skb->data[i]);
 798                        return 1;
 799                }
 800
 801                if (skb->data[++i] != stat_len) {
 802                        netdev_info(dev, "Invalid LMI PVC status IE length (%u)\n",
 803                                    skb->data[i]);
 804                        return 1;
 805                }
 806                i++;
 807
 808                new = !! (skb->data[i + 2] & 0x08);
 809                active = !! (skb->data[i + 2] & 0x02);
 810                if (lmi == LMI_CISCO) {
 811                        dlci = (skb->data[i] << 8) | skb->data[i + 1];
 812                        bw = (skb->data[i + 3] << 16) |
 813                                (skb->data[i + 4] << 8) |
 814                                (skb->data[i + 5]);
 815                } else {
 816                        dlci = ((skb->data[i] & 0x3F) << 4) |
 817                                ((skb->data[i + 1] & 0x78) >> 3);
 818                        bw = 0;
 819                }
 820
 821                pvc = add_pvc(dev, dlci);
 822
 823                if (!pvc && !no_ram) {
 824                        netdev_warn(dev, "Memory squeeze on fr_lmi_recv()\n");
 825                        no_ram = 1;
 826                }
 827
 828                if (pvc) {
 829                        pvc->state.exist = 1;
 830                        pvc->state.deleted = 0;
 831                        if (active != pvc->state.active ||
 832                            new != pvc->state.new ||
 833                            bw != pvc->state.bandwidth ||
 834                            !pvc->state.exist) {
 835                                pvc->state.new = new;
 836                                pvc->state.active = active;
 837                                pvc->state.bandwidth = bw;
 838                                pvc_carrier(active, pvc);
 839                                fr_log_dlci_active(pvc);
 840                        }
 841                }
 842
 843                i += stat_len;
 844        }
 845
 846        pvc = state(hdlc)->first_pvc;
 847
 848        while (pvc) {
 849                if (pvc->state.deleted && pvc->state.exist) {
 850                        pvc_carrier(0, pvc);
 851                        pvc->state.active = pvc->state.new = 0;
 852                        pvc->state.exist = 0;
 853                        pvc->state.bandwidth = 0;
 854                        fr_log_dlci_active(pvc);
 855                }
 856                pvc = pvc->next;
 857        }
 858
 859        /* Next full report after N391 polls */
 860        state(hdlc)->n391cnt = state(hdlc)->settings.n391;
 861
 862        return 0;
 863}
 864
 865
 866static int fr_rx(struct sk_buff *skb)
 867{
 868        struct net_device *frad = skb->dev;
 869        hdlc_device *hdlc = dev_to_hdlc(frad);
 870        struct fr_hdr *fh = (struct fr_hdr *)skb->data;
 871        u8 *data = skb->data;
 872        u16 dlci;
 873        struct pvc_device *pvc;
 874        struct net_device *dev = NULL;
 875
 876        if (skb->len <= 4 || fh->ea1 || data[2] != FR_UI)
 877                goto rx_error;
 878
 879        dlci = q922_to_dlci(skb->data);
 880
 881        if ((dlci == LMI_CCITT_ANSI_DLCI &&
 882             (state(hdlc)->settings.lmi == LMI_ANSI ||
 883              state(hdlc)->settings.lmi == LMI_CCITT)) ||
 884            (dlci == LMI_CISCO_DLCI &&
 885             state(hdlc)->settings.lmi == LMI_CISCO)) {
 886                if (fr_lmi_recv(frad, skb))
 887                        goto rx_error;
 888                dev_kfree_skb_any(skb);
 889                return NET_RX_SUCCESS;
 890        }
 891
 892        pvc = find_pvc(hdlc, dlci);
 893        if (!pvc) {
 894#ifdef DEBUG_PKT
 895                netdev_info(frad, "No PVC for received frame's DLCI %d\n",
 896                            dlci);
 897#endif
 898                dev_kfree_skb_any(skb);
 899                return NET_RX_DROP;
 900        }
 901
 902        if (pvc->state.fecn != fh->fecn) {
 903#ifdef DEBUG_ECN
 904                printk(KERN_DEBUG "%s: DLCI %d FECN O%s\n", frad->name,
 905                       dlci, fh->fecn ? "N" : "FF");
 906#endif
 907                pvc->state.fecn ^= 1;
 908        }
 909
 910        if (pvc->state.becn != fh->becn) {
 911#ifdef DEBUG_ECN
 912                printk(KERN_DEBUG "%s: DLCI %d BECN O%s\n", frad->name,
 913                       dlci, fh->becn ? "N" : "FF");
 914#endif
 915                pvc->state.becn ^= 1;
 916        }
 917
 918
 919        if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) {
 920                frad->stats.rx_dropped++;
 921                return NET_RX_DROP;
 922        }
 923
 924        if (data[3] == NLPID_IP) {
 925                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
 926                dev = pvc->main;
 927                skb->protocol = htons(ETH_P_IP);
 928
 929        } else if (data[3] == NLPID_IPV6) {
 930                skb_pull(skb, 4); /* Remove 4-byte header (hdr, UI, NLPID) */
 931                dev = pvc->main;
 932                skb->protocol = htons(ETH_P_IPV6);
 933
 934        } else if (skb->len > 10 && data[3] == FR_PAD &&
 935                   data[4] == NLPID_SNAP && data[5] == FR_PAD) {
 936                u16 oui = ntohs(*(__be16*)(data + 6));
 937                u16 pid = ntohs(*(__be16*)(data + 8));
 938                skb_pull(skb, 10);
 939
 940                switch ((((u32)oui) << 16) | pid) {
 941                case ETH_P_ARP: /* routed frame with SNAP */
 942                case ETH_P_IPX:
 943                case ETH_P_IP:  /* a long variant */
 944                case ETH_P_IPV6:
 945                        dev = pvc->main;
 946                        skb->protocol = htons(pid);
 947                        break;
 948
 949                case 0x80C20007: /* bridged Ethernet frame */
 950                        if ((dev = pvc->ether) != NULL)
 951                                skb->protocol = eth_type_trans(skb, dev);
 952                        break;
 953
 954                default:
 955                        netdev_info(frad, "Unsupported protocol, OUI=%x PID=%x\n",
 956                                    oui, pid);
 957                        dev_kfree_skb_any(skb);
 958                        return NET_RX_DROP;
 959                }
 960        } else {
 961                netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",
 962                            data[3], skb->len);
 963                dev_kfree_skb_any(skb);
 964                return NET_RX_DROP;
 965        }
 966
 967        if (dev) {
 968                dev->stats.rx_packets++; /* PVC traffic */
 969                dev->stats.rx_bytes += skb->len;
 970                if (pvc->state.becn)
 971                        dev->stats.rx_compressed++;
 972                skb->dev = dev;
 973                netif_rx(skb);
 974                return NET_RX_SUCCESS;
 975        } else {
 976                dev_kfree_skb_any(skb);
 977                return NET_RX_DROP;
 978        }
 979
 980 rx_error:
 981        frad->stats.rx_errors++; /* Mark error */
 982        dev_kfree_skb_any(skb);
 983        return NET_RX_DROP;
 984}
 985
 986
 987
 988static void fr_start(struct net_device *dev)
 989{
 990        hdlc_device *hdlc = dev_to_hdlc(dev);
 991#ifdef DEBUG_LINK
 992        printk(KERN_DEBUG "fr_start\n");
 993#endif
 994        if (state(hdlc)->settings.lmi != LMI_NONE) {
 995                state(hdlc)->reliable = 0;
 996                state(hdlc)->dce_changed = 1;
 997                state(hdlc)->request = 0;
 998                state(hdlc)->fullrep_sent = 0;
 999                state(hdlc)->last_errors = 0xFFFFFFFF;
1000                state(hdlc)->n391cnt = 0;
1001                state(hdlc)->txseq = state(hdlc)->rxseq = 0;
1002
1003                state(hdlc)->dev = dev;
1004                timer_setup(&state(hdlc)->timer, fr_timer, 0);
1005                /* First poll after 1 s */
1006                state(hdlc)->timer.expires = jiffies + HZ;
1007                add_timer(&state(hdlc)->timer);
1008        } else
1009                fr_set_link_state(1, dev);
1010}
1011
1012
1013static void fr_stop(struct net_device *dev)
1014{
1015        hdlc_device *hdlc = dev_to_hdlc(dev);
1016#ifdef DEBUG_LINK
1017        printk(KERN_DEBUG "fr_stop\n");
1018#endif
1019        if (state(hdlc)->settings.lmi != LMI_NONE)
1020                del_timer_sync(&state(hdlc)->timer);
1021        fr_set_link_state(0, dev);
1022}
1023
1024
1025static void fr_close(struct net_device *dev)
1026{
1027        hdlc_device *hdlc = dev_to_hdlc(dev);
1028        struct pvc_device *pvc = state(hdlc)->first_pvc;
1029
1030        while (pvc) {           /* Shutdown all PVCs for this FRAD */
1031                if (pvc->main)
1032                        dev_close(pvc->main);
1033                if (pvc->ether)
1034                        dev_close(pvc->ether);
1035                pvc = pvc->next;
1036        }
1037}
1038
1039
1040static void pvc_setup(struct net_device *dev)
1041{
1042        dev->type = ARPHRD_DLCI;
1043        dev->flags = IFF_POINTOPOINT;
1044        dev->hard_header_len = 10;
1045        dev->addr_len = 2;
1046        netif_keep_dst(dev);
1047}
1048
1049static const struct net_device_ops pvc_ops = {
1050        .ndo_open       = pvc_open,
1051        .ndo_stop       = pvc_close,
1052        .ndo_start_xmit = pvc_xmit,
1053        .ndo_do_ioctl   = pvc_ioctl,
1054};
1055
1056static int fr_add_pvc(struct net_device *frad, unsigned int dlci, int type)
1057{
1058        hdlc_device *hdlc = dev_to_hdlc(frad);
1059        struct pvc_device *pvc;
1060        struct net_device *dev;
1061        int used;
1062
1063        if ((pvc = add_pvc(frad, dlci)) == NULL) {
1064                netdev_warn(frad, "Memory squeeze on fr_add_pvc()\n");
1065                return -ENOBUFS;
1066        }
1067
1068        if (*get_dev_p(pvc, type))
1069                return -EEXIST;
1070
1071        used = pvc_is_used(pvc);
1072
1073        if (type == ARPHRD_ETHER)
1074                dev = alloc_netdev(0, "pvceth%d", NET_NAME_UNKNOWN,
1075                                   ether_setup);
1076        else
1077                dev = alloc_netdev(0, "pvc%d", NET_NAME_UNKNOWN, pvc_setup);
1078
1079        if (!dev) {
1080                netdev_warn(frad, "Memory squeeze on fr_pvc()\n");
1081                delete_unused_pvcs(hdlc);
1082                return -ENOBUFS;
1083        }
1084
1085        if (type == ARPHRD_ETHER) {
1086                dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1087                eth_hw_addr_random(dev);
1088        } else {
1089                *(__be16*)dev->dev_addr = htons(dlci);
1090                dlci_to_q922(dev->broadcast, dlci);
1091        }
1092        dev->netdev_ops = &pvc_ops;
1093        dev->mtu = HDLC_MAX_MTU;
1094        dev->min_mtu = 68;
1095        dev->max_mtu = HDLC_MAX_MTU;
1096        dev->priv_flags |= IFF_NO_QUEUE;
1097        dev->ml_priv = pvc;
1098
1099        if (register_netdevice(dev) != 0) {
1100                free_netdev(dev);
1101                delete_unused_pvcs(hdlc);
1102                return -EIO;
1103        }
1104
1105        dev->needs_free_netdev = true;
1106        *get_dev_p(pvc, type) = dev;
1107        if (!used) {
1108                state(hdlc)->dce_changed = 1;
1109                state(hdlc)->dce_pvc_count++;
1110        }
1111        return 0;
1112}
1113
1114
1115
1116static int fr_del_pvc(hdlc_device *hdlc, unsigned int dlci, int type)
1117{
1118        struct pvc_device *pvc;
1119        struct net_device *dev;
1120
1121        if ((pvc = find_pvc(hdlc, dlci)) == NULL)
1122                return -ENOENT;
1123
1124        if ((dev = *get_dev_p(pvc, type)) == NULL)
1125                return -ENOENT;
1126
1127        if (dev->flags & IFF_UP)
1128                return -EBUSY;          /* PVC in use */
1129
1130        unregister_netdevice(dev); /* the destructor will free_netdev(dev) */
1131        *get_dev_p(pvc, type) = NULL;
1132
1133        if (!pvc_is_used(pvc)) {
1134                state(hdlc)->dce_pvc_count--;
1135                state(hdlc)->dce_changed = 1;
1136        }
1137        delete_unused_pvcs(hdlc);
1138        return 0;
1139}
1140
1141
1142
1143static void fr_destroy(struct net_device *frad)
1144{
1145        hdlc_device *hdlc = dev_to_hdlc(frad);
1146        struct pvc_device *pvc = state(hdlc)->first_pvc;
1147        state(hdlc)->first_pvc = NULL; /* All PVCs destroyed */
1148        state(hdlc)->dce_pvc_count = 0;
1149        state(hdlc)->dce_changed = 1;
1150
1151        while (pvc) {
1152                struct pvc_device *next = pvc->next;
1153                /* destructors will free_netdev() main and ether */
1154                if (pvc->main)
1155                        unregister_netdevice(pvc->main);
1156
1157                if (pvc->ether)
1158                        unregister_netdevice(pvc->ether);
1159
1160                kfree(pvc);
1161                pvc = next;
1162        }
1163}
1164
1165
1166static struct hdlc_proto proto = {
1167        .close          = fr_close,
1168        .start          = fr_start,
1169        .stop           = fr_stop,
1170        .detach         = fr_destroy,
1171        .ioctl          = fr_ioctl,
1172        .netif_rx       = fr_rx,
1173        .module         = THIS_MODULE,
1174};
1175
1176
1177static int fr_ioctl(struct net_device *dev, struct ifreq *ifr)
1178{
1179        fr_proto __user *fr_s = ifr->ifr_settings.ifs_ifsu.fr;
1180        const size_t size = sizeof(fr_proto);
1181        fr_proto new_settings;
1182        hdlc_device *hdlc = dev_to_hdlc(dev);
1183        fr_proto_pvc pvc;
1184        int result;
1185
1186        switch (ifr->ifr_settings.type) {
1187        case IF_GET_PROTO:
1188                if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1189                        return -EINVAL;
1190                ifr->ifr_settings.type = IF_PROTO_FR;
1191                if (ifr->ifr_settings.size < size) {
1192                        ifr->ifr_settings.size = size; /* data size wanted */
1193                        return -ENOBUFS;
1194                }
1195                if (copy_to_user(fr_s, &state(hdlc)->settings, size))
1196                        return -EFAULT;
1197                return 0;
1198
1199        case IF_PROTO_FR:
1200                if (!capable(CAP_NET_ADMIN))
1201                        return -EPERM;
1202
1203                if (dev->flags & IFF_UP)
1204                        return -EBUSY;
1205
1206                if (copy_from_user(&new_settings, fr_s, size))
1207                        return -EFAULT;
1208
1209                if (new_settings.lmi == LMI_DEFAULT)
1210                        new_settings.lmi = LMI_ANSI;
1211
1212                if ((new_settings.lmi != LMI_NONE &&
1213                     new_settings.lmi != LMI_ANSI &&
1214                     new_settings.lmi != LMI_CCITT &&
1215                     new_settings.lmi != LMI_CISCO) ||
1216                    new_settings.t391 < 1 ||
1217                    new_settings.t392 < 2 ||
1218                    new_settings.n391 < 1 ||
1219                    new_settings.n392 < 1 ||
1220                    new_settings.n393 < new_settings.n392 ||
1221                    new_settings.n393 > 32 ||
1222                    (new_settings.dce != 0 &&
1223                     new_settings.dce != 1))
1224                        return -EINVAL;
1225
1226                result=hdlc->attach(dev, ENCODING_NRZ,PARITY_CRC16_PR1_CCITT);
1227                if (result)
1228                        return result;
1229
1230                if (dev_to_hdlc(dev)->proto != &proto) { /* Different proto */
1231                        result = attach_hdlc_protocol(dev, &proto,
1232                                                      sizeof(struct frad_state));
1233                        if (result)
1234                                return result;
1235                        state(hdlc)->first_pvc = NULL;
1236                        state(hdlc)->dce_pvc_count = 0;
1237                }
1238                memcpy(&state(hdlc)->settings, &new_settings, size);
1239                dev->type = ARPHRD_FRAD;
1240                call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
1241                return 0;
1242
1243        case IF_PROTO_FR_ADD_PVC:
1244        case IF_PROTO_FR_DEL_PVC:
1245        case IF_PROTO_FR_ADD_ETH_PVC:
1246        case IF_PROTO_FR_DEL_ETH_PVC:
1247                if (dev_to_hdlc(dev)->proto != &proto) /* Different proto */
1248                        return -EINVAL;
1249
1250                if (!capable(CAP_NET_ADMIN))
1251                        return -EPERM;
1252
1253                if (copy_from_user(&pvc, ifr->ifr_settings.ifs_ifsu.fr_pvc,
1254                                   sizeof(fr_proto_pvc)))
1255                        return -EFAULT;
1256
1257                if (pvc.dlci <= 0 || pvc.dlci >= 1024)
1258                        return -EINVAL; /* Only 10 bits, DLCI 0 reserved */
1259
1260                if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC ||
1261                    ifr->ifr_settings.type == IF_PROTO_FR_DEL_ETH_PVC)
1262                        result = ARPHRD_ETHER; /* bridged Ethernet device */
1263                else
1264                        result = ARPHRD_DLCI;
1265
1266                if (ifr->ifr_settings.type == IF_PROTO_FR_ADD_PVC ||
1267                    ifr->ifr_settings.type == IF_PROTO_FR_ADD_ETH_PVC)
1268                        return fr_add_pvc(dev, pvc.dlci, result);
1269                else
1270                        return fr_del_pvc(hdlc, pvc.dlci, result);
1271        }
1272
1273        return -EINVAL;
1274}
1275
1276
1277static int __init mod_init(void)
1278{
1279        register_hdlc_protocol(&proto);
1280        return 0;
1281}
1282
1283
1284static void __exit mod_exit(void)
1285{
1286        unregister_hdlc_protocol(&proto);
1287}
1288
1289
1290module_init(mod_init);
1291module_exit(mod_exit);
1292
1293MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
1294MODULE_DESCRIPTION("Frame-Relay protocol support for generic HDLC");
1295MODULE_LICENSE("GPL v2");
1296