usr.sbin/ppp/ipv6cp.c

/*-
 * Copyright (c) 2001 Brian Somers <brian@Awfulhak.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD: head/usr.sbin/ppp/ipv6cp.c 81888 2001-08-18 13:04:52Z brian $
 */

#include <sys/param.h>
#include <netinet/in_systm.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <sys/socket.h>
#include <net/route.h>
#include <net/if.h>
#include <sys/un.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <termios.h>

#include "layer.h"
#include "defs.h"
#include "mbuf.h"
#include "timer.h"
#include "fsm.h"
#include "iplist.h"
#include "throughput.h"
#include "slcompress.h"
#include "lqr.h"
#include "hdlc.h"
#include "lcp.h"
#include "ncpaddr.h"
#include "ip.h"
#include "ipcp.h"
#include "ipv6cp.h"
#include "filter.h"
#include "descriptor.h"
#include "ccp.h"
#include "link.h"
#include "mp.h"
#ifndef NORADIUS
#include "radius.h"
#endif
#include "ncp.h"
#include "bundle.h"
#include "route.h"
#include "iface.h"
#include "log.h"
#include "proto.h"
#include "command.h"
#include "prompt.h"
#include "async.h"
#include "physical.h"
#include "probe.h"


#ifndef NOINET6
static int ipv6cp_LayerUp(struct fsm *);
static void ipv6cp_LayerDown(struct fsm *);
static void ipv6cp_LayerStart(struct fsm *);
static void ipv6cp_LayerFinish(struct fsm *);
static void ipv6cp_InitRestartCounter(struct fsm *, int);
static void ipv6cp_SendConfigReq(struct fsm *);
static void ipv6cp_SentTerminateReq(struct fsm *);
static void ipv6cp_SendTerminateAck(struct fsm *, u_char);
static void ipv6cp_DecodeConfig(struct fsm *, u_char *, int, int,
                                struct fsm_decode *);

static struct fsm_callbacks ipv6cp_Callbacks = {
  ipv6cp_LayerUp,
  ipv6cp_LayerDown,
  ipv6cp_LayerStart,
  ipv6cp_LayerFinish,
  ipv6cp_InitRestartCounter,
  ipv6cp_SendConfigReq,
  ipv6cp_SentTerminateReq,
  ipv6cp_SendTerminateAck,
  ipv6cp_DecodeConfig,
  fsm_NullRecvResetReq,
  fsm_NullRecvResetAck
};

static u_int32_t
GenerateToken(void)
{
  /* Generate random number which will be used as negotiation token */
  randinit();

  return random() + 1;
}

static int
ipcp_SetIPv6address(struct ipv6cp *ipv6cp, u_int32_t mytok, u_int32_t histok)
{
  struct bundle *bundle = ipv6cp->fsm.bundle;
  struct in6_addr myaddr, hisaddr;
  struct ncprange myrange;
  struct sockaddr_storage ssdst, ssgw, ssmask;
  struct sockaddr *sadst, *sagw, *samask;

  sadst = (struct sockaddr *)&ssdst;
  sagw = (struct sockaddr *)&ssgw;
  samask = (struct sockaddr *)&ssmask;

  memset(&myaddr, '\0', sizeof myaddr);
  memset(&hisaddr, '\0', sizeof hisaddr);

  myaddr.s6_addr[0] = 0xfe;
  myaddr.s6_addr[1] = 0x80;
  *(u_int32_t *)(myaddr.s6_addr + 12) = htonl(mytok);

  hisaddr.s6_addr[0] = 0xfe;
  hisaddr.s6_addr[1] = 0x80;
  *(u_int32_t *)(hisaddr.s6_addr + 12) = htonl(histok);

  ncpaddr_setip6(&ipv6cp->myaddr, &myaddr);
  ncpaddr_setip6(&ipv6cp->hisaddr, &hisaddr);
  ncprange_sethost(&myrange, &ipv6cp->myaddr);

  if (!iface_Add(bundle->iface, &bundle->ncp, &myrange, &ipv6cp->hisaddr,
                 IFACE_ADD_FIRST|IFACE_FORCE_ADD|IFACE_SYSTEM))
    return 0;

  if (!Enabled(bundle, OPT_IFACEALIAS))
    iface_Clear(bundle->iface, &bundle->ncp, AF_INET6,
                IFACE_CLEAR_ALIASES|IFACE_SYSTEM);

  if (bundle->ncp.cfg.sendpipe > 0 || bundle->ncp.cfg.recvpipe > 0) {
    ncprange_getsa(&myrange, &ssgw, &ssmask);
    if (ncpaddr_isset(&ipv6cp->hisaddr))
      ncpaddr_getsa(&ipv6cp->hisaddr, &ssdst);
    else
      sadst = NULL;
    rt_Update(bundle, sadst, sagw, samask);
  }

  if (Enabled(bundle, OPT_SROUTES))
    route_Change(bundle, bundle->ncp.route, &ipv6cp->myaddr, &ipv6cp->hisaddr);

#ifndef NORADIUS
  if (bundle->radius.valid)
    route_Change(bundle, bundle->radius.routes, &ipv6cp->myaddr,
                 &ipv6cp->hisaddr);
#endif

  return 1;	/* Ok */
}

void
ipv6cp_Init(struct ipv6cp *ipv6cp, struct bundle *bundle, struct link *l,
                 const struct fsm_parent *parent)
{
  static const char * const timer_names[] =
    {"IPV6CP restart", "IPV6CP openmode", "IPV6CP stopped"};
  int n;

  fsm_Init(&ipv6cp->fsm, "IPV6CP", PROTO_IPV6CP, 1, IPV6CP_MAXCODE, LogIPV6CP,
           bundle, l, parent, &ipv6cp_Callbacks, timer_names);

  ipv6cp->cfg.fsm.timeout = DEF_FSMRETRY;
  ipv6cp->cfg.fsm.maxreq = DEF_FSMTRIES;
  ipv6cp->cfg.fsm.maxtrm = DEF_FSMTRIES;

  ipv6cp->my_token = GenerateToken();
  while ((ipv6cp->peer_token = GenerateToken()) == ipv6cp->my_token)
    ;

  n = 100;
  while (n &&
         !ipcp_SetIPv6address(ipv6cp, ipv6cp->my_token, ipv6cp->peer_token))
    while (n && (ipv6cp->my_token = GenerateToken()) == ipv6cp->peer_token)
      n--;

  throughput_init(&ipv6cp->throughput, SAMPLE_PERIOD);
  memset(ipv6cp->Queue, '\0', sizeof ipv6cp->Queue);
  ipv6cp_Setup(ipv6cp);
}

void
ipv6cp_Destroy(struct ipv6cp *ipv6cp)
{
  throughput_destroy(&ipv6cp->throughput);
}

void
ipv6cp_Setup(struct ipv6cp *ipv6cp)
{
  ncpaddr_init(&ipv6cp->myaddr);
  ncpaddr_init(&ipv6cp->hisaddr);

  ipv6cp->his_reject = 0;
  ipv6cp->my_reject = 0;
}

void
ipv6cp_SetLink(struct ipv6cp *ipv6cp, struct link *l)
{
  ipv6cp->fsm.link = l;
}

int
ipv6cp_Show(struct cmdargs const *arg)
{
  struct ipv6cp *ipv6cp = &arg->bundle->ncp.ipv6cp;

  if (!probe.ipv6_available) {
    prompt_Printf(arg->prompt, "ipv6 not available\n");
    return 0;
  }

  prompt_Printf(arg->prompt, "%s [%s]\n", ipv6cp->fsm.name,
                State2Nam(ipv6cp->fsm.state));
  if (ipv6cp->fsm.state == ST_OPENED) {
    prompt_Printf(arg->prompt, " His side:        %s\n",
	          ncpaddr_ntoa(&ipv6cp->hisaddr));
    prompt_Printf(arg->prompt, " My side:         %s\n",
	          ncpaddr_ntoa(&ipv6cp->myaddr));
    prompt_Printf(arg->prompt, " Queued packets:  %lu\n",
                  (unsigned long)ipv6cp_QueueLen(ipv6cp));
  }

  prompt_Printf(arg->prompt, "\nDefaults:\n");
  prompt_Printf(arg->prompt, "  FSM retry = %us, max %u Config"
                " REQ%s, %u Term REQ%s\n\n", ipv6cp->cfg.fsm.timeout,
                ipv6cp->cfg.fsm.maxreq, ipv6cp->cfg.fsm.maxreq == 1 ? "" : "s",
                ipv6cp->cfg.fsm.maxtrm, ipv6cp->cfg.fsm.maxtrm == 1 ? "" : "s");

  throughput_disp(&ipv6cp->throughput, arg->prompt);

  return 0;
}

struct mbuf *
ipv6cp_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
{
  /* Got PROTO_IPV6CP from link */
  m_settype(bp, MB_IPV6CPIN);
  if (bundle_Phase(bundle) == PHASE_NETWORK && probe.ipv6_available)
    fsm_Input(&bundle->ncp.ipv6cp.fsm, bp);
  else {
    if (bundle_Phase(bundle) < PHASE_NETWORK)
      log_Printf(LogIPV6CP, "%s: Error: Unexpected IPV6CP in phase %s"
                 " (ignored)\n", l->name, bundle_PhaseName(bundle));
    m_freem(bp);
  }
  return NULL;
}

void
ipv6cp_AddInOctets(struct ipv6cp *ipv6cp, int n)
{
  throughput_addin(&ipv6cp->throughput, n);
}

void
ipv6cp_AddOutOctets(struct ipv6cp *ipv6cp, int n)
{
  throughput_addout(&ipv6cp->throughput, n);
}

void
ipv6cp_IfaceAddrAdded(struct ipv6cp *ipv6cp, const struct iface_addr *addr)
{
}

void
ipv6cp_IfaceAddrDeleted(struct ipv6cp *ipv6cp, const struct iface_addr *addr)
{
}

int
ipv6cp_InterfaceUp(struct ipv6cp *ipv6cp)
{
  if (!ipcp_SetIPv6address(ipv6cp, ipv6cp->my_token, ipv6cp->peer_token)) {
    log_Printf(LogERROR, "ipv6cp_InterfaceUp: unable to set ipv6 address\n");
    return 0;
  }

  if (!iface_SetFlags(ipv6cp->fsm.bundle->iface->name, IFF_UP)) {
    log_Printf(LogERROR, "ipv6cp_InterfaceUp: Can't set the IFF_UP"
               " flag on %s\n", ipv6cp->fsm.bundle->iface->name);
    return 0;
  }

  return 1;
}

size_t
ipv6cp_QueueLen(struct ipv6cp *ipv6cp)
{
  struct mqueue *q;
  size_t result;

  result = 0;
  for (q = ipv6cp->Queue; q < ipv6cp->Queue + IPV6CP_QUEUES(ipv6cp); q++)
    result += q->len;

  return result;
}

int
ipv6cp_PushPacket(struct ipv6cp *ipv6cp, struct link *l)
{
  struct bundle *bundle = ipv6cp->fsm.bundle;
  struct mqueue *queue;
  struct mbuf *bp;
  int m_len;
  u_int32_t secs = 0;
  unsigned alivesecs = 0;

  if (ipv6cp->fsm.state != ST_OPENED)
    return 0;

  /*
   * If ccp is not open but is required, do nothing.
   */
  if (l->ccp.fsm.state != ST_OPENED && ccp_Required(&l->ccp)) {
    log_Printf(LogPHASE, "%s: Not transmitting... waiting for CCP\n", l->name);
    return 0;
  }

  queue = ipv6cp->Queue + IPV6CP_QUEUES(ipv6cp) - 1;
  do {
    if (queue->top) {
      bp = m_dequeue(queue);
      bp = mbuf_Read(bp, &secs, sizeof secs);
      bp = m_pullup(bp);
      m_len = m_length(bp);
      if (!FilterCheck(MBUF_CTOP(bp), AF_INET6, &bundle->filter.alive,
                       &alivesecs)) {
        if (secs == 0)
          secs = alivesecs;
        bundle_StartIdleTimer(bundle, secs);
      }
      link_PushPacket(l, bp, bundle, 0, PROTO_IPV6);
      ipv6cp_AddOutOctets(ipv6cp, m_len);
      return 1;
    }
  } while (queue-- != ipv6cp->Queue);

  return 0;
}

static int
ipv6cp_LayerUp(struct fsm *fp)
{
  /* We're now up */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);
  char tbuff[40];

  log_Printf(LogIPV6CP, "%s: LayerUp.\n", fp->link->name);
  if (!ipv6cp_InterfaceUp(ipv6cp))
    return 0;

  snprintf(tbuff, sizeof tbuff, "%s", ncpaddr_ntoa(&ipv6cp->myaddr));
  log_Printf(LogIPV6CP, "myaddr %s hisaddr = %s\n",
             tbuff, ncpaddr_ntoa(&ipv6cp->hisaddr));

  /* XXX: Call radius_Account() and system_Select() */

  fp->more.reqs = fp->more.naks = fp->more.rejs = ipv6cp->cfg.fsm.maxreq * 3;
  log_DisplayPrompts();

  return 1;
}

static void
ipv6cp_LayerDown(struct fsm *fp)
{
  /* About to come down */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);
  static int recursing;
  char addr[40];

  if (!recursing++) {
    snprintf(addr, sizeof addr, "%s", ncpaddr_ntoa(&ipv6cp->myaddr));
    log_Printf(LogIPV6CP, "%s: LayerDown: %s\n", fp->link->name, addr);

    /* XXX: Call radius_Account() and system_Select() */

    ipv6cp_Setup(ipv6cp);
  }
  recursing--;
}

static void
ipv6cp_LayerStart(struct fsm *fp)
{
  /* We're about to start up ! */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);

  log_Printf(LogIPV6CP, "%s: LayerStart.\n", fp->link->name);
  throughput_start(&ipv6cp->throughput, "IPV6CP throughput",
                   Enabled(fp->bundle, OPT_THROUGHPUT));
  fp->more.reqs = fp->more.naks = fp->more.rejs = ipv6cp->cfg.fsm.maxreq * 3;
  ipv6cp->peer_tokenreq = 0;
}

static void
ipv6cp_LayerFinish(struct fsm *fp)
{
  /* We're now down */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);

  log_Printf(LogIPV6CP, "%s: LayerFinish.\n", fp->link->name);
  throughput_stop(&ipv6cp->throughput);
  throughput_log(&ipv6cp->throughput, LogIPV6CP, NULL);
}

static void
ipv6cp_InitRestartCounter(struct fsm *fp, int what)
{
  /* Set fsm timer load */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);

  fp->FsmTimer.load = ipv6cp->cfg.fsm.timeout * SECTICKS;
  switch (what) {
    case FSM_REQ_TIMER:
      fp->restart = ipv6cp->cfg.fsm.maxreq;
      break;
    case FSM_TRM_TIMER:
      fp->restart = ipv6cp->cfg.fsm.maxtrm;
      break;
    default:
      fp->restart = 1;
      break;
  }
}

static void
ipv6cp_SendConfigReq(struct fsm *fp)
{
  /* Send config REQ please */
  struct physical *p = link2physical(fp->link);
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);
  u_char buff[6];
  struct lcp_opt *o;

  o = (struct lcp_opt *)buff;

  if ((p && !physical_IsSync(p)) || !REJECTED(ipv6cp, TY_TOKEN)) {
    memcpy(o->data, &ipv6cp->my_token, 4);
    INC_LCP_OPT(TY_TOKEN, 6, o);
  }

  fsm_Output(fp, CODE_CONFIGREQ, fp->reqid, buff, (u_char *)o - buff,
             MB_IPV6CPOUT);
}

static void
ipv6cp_SentTerminateReq(struct fsm *fp)
{
  /* Term REQ just sent by FSM */
}

static void
ipv6cp_SendTerminateAck(struct fsm *fp, u_char id)
{
  /* Send Term ACK please */
  fsm_Output(fp, CODE_TERMACK, id, NULL, 0, MB_IPV6CPOUT);
}

static const char *
protoname(int proto)
{
  static const char *cftypes[] = { "TOKEN", "COMPPROTO" };

  if (proto > 0 && proto <= sizeof cftypes / sizeof *cftypes)
    return cftypes[proto - 1];

  return NumStr(proto, NULL, 0);
}

static void
ipv6cp_ValidateToken(struct ipv6cp *ipv6cp, u_int32_t token,
                     struct fsm_decode *dec)
{
  if (token != 0 && token != ipv6cp->my_token)
    ipv6cp->peer_token = token;

  if (token == ipv6cp->peer_token) {
    *dec->ackend++ = TY_TOKEN;
    *dec->ackend++ = 6;
    memcpy(dec->ackend, &ipv6cp->peer_token, 4);
    dec->ackend += 4;
  } else {
    *dec->nakend++ = TY_TOKEN;
    *dec->nakend++ = 6;
    memcpy(dec->nakend, &ipv6cp->peer_token, 4);
    dec->nakend += 4;
  }
}

static void
ipv6cp_DecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
                    struct fsm_decode *dec)
{
  /* Deal with incoming PROTO_IPV6CP */
  struct ipv6cp *ipv6cp = fsm2ipv6cp(fp);
  int type, length, n;
  char tbuff[100];
  u_int32_t token;

  while (plen >= sizeof(struct fsmconfig)) {
    type = *cp;
    length = cp[1];

    if (length == 0) {
      log_Printf(LogIPV6CP, "%s: IPV6CP size zero\n", fp->link->name);
      break;
    }

    snprintf(tbuff, sizeof tbuff, " %s[%d] ", protoname(type), length);

    switch (type) {
    case TY_TOKEN:
      memcpy(&token, cp + 2, 4);
      log_Printf(LogIPV6CP, "%s 0x%08lx\n", tbuff, (unsigned long)token);

      switch (mode_type) {
      case MODE_REQ:
        ipv6cp->peer_tokenreq = 1;
        ipv6cp_ValidateToken(ipv6cp, token, dec);
	break;

      case MODE_NAK:
        if (token == 0) {
	  log_Printf(log_IsKept(LogIPV6CP) ? LogIPV6CP : LogPHASE,
                     "0x00000000: Unacceptable token!\n");
          fsm_Close(&ipv6cp->fsm);
        } else if (token == ipv6cp->peer_token)
	  log_Printf(log_IsKept(LogIPV6CP) ? LogIPV6CP : LogPHASE,
                    "0x08lx: Unacceptable token!\n", (unsigned long)token);
        else if (token != ipv6cp->my_token) {
          n = 100;
          while (n && !ipcp_SetIPv6address(ipv6cp, token, ipv6cp->peer_token))
            while (n && (token = GenerateToken()) == ipv6cp->peer_token)
              n--;

          if (n == 0) {
	    log_Printf(log_IsKept(LogIPV6CP) ? LogIPV6CP : LogPHASE,
                       "0x00000000: Unacceptable token!\n");
            fsm_Close(&ipv6cp->fsm);
          } else {
	    log_Printf(LogIPV6CP, "%s changing token: 0x%08lx --> 0x%08lx\n",
                       tbuff, (unsigned long)ipv6cp->my_token,
                       (unsigned long)token);
            ipv6cp->my_token = token;
            bundle_AdjustFilters(fp->bundle, &ipv6cp->myaddr, NULL);
          }
        }
	break;

      case MODE_REJ:
	ipv6cp->his_reject |= (1 << type);
	break;
      }
      break;

    default:
      if (mode_type != MODE_NOP) {
        ipv6cp->my_reject |= (1 << type);
        memcpy(dec->rejend, cp, length);
        dec->rejend += length;
      }
      break;
    }
    plen -= length;
    cp += length;
  }

  if (mode_type != MODE_NOP) {
    if (mode_type == MODE_REQ && !ipv6cp->peer_tokenreq) {
      if (dec->rejend == dec->rej && dec->nakend == dec->nak) {
        /*
         * Pretend the peer has requested a TOKEN.
         * We do this to ensure that we only send one NAK if the only
         * reason for the NAK is because the peer isn't sending a
         * TY_TOKEN REQ.  This stops us from repeatedly trying to tell
         * the peer that we have to have an IP address on their end.
         */
        ipv6cp->peer_tokenreq = 1;
      }
      ipv6cp_ValidateToken(ipv6cp, 0, dec);
    }
    if (dec->rejend != dec->rej) {
      /* rejects are preferred */
      dec->ackend = dec->ack;
      dec->nakend = dec->nak;
    } else if (dec->nakend != dec->nak)
      /* then NAKs */
      dec->ackend = dec->ack;
  }
}
#endif