Back out the previous fix to deal with kernels that don't support IPv6,

and implement a far more subtle and correct fix.

The reason behind the infinite loop was that ppp was trying to make up
initial IPv6 numbers and wasn't giving up when it failed unexpectedly to
assign the addresses it just fabricated to it's interface (thinking that
the reason was because another interface was using the same address).
It now attempts this up to 100 times before just failing and trying to
muddle along (in reality, this should never happen more than a couple
of times unless our random number generator doesn't work).

Also, when IPv6 is not available, don't even try to assign the IPv6
interface address in the first place...

6 files changed, 44 insertions, 69 deletions

diff --git a/usr.sbin/ppp/bundle.c b/usr.sbin/ppp/bundle.c
index 8f0863f..adf5257 100644
--- a/usr.sbin/ppp/bundle.c
+++ b/usr.sbin/ppp/bundle.c
@@ -555,7 +555,7 @@ bundle_DescriptorRead(struct fdescriptor *d, struct bundle *bundle,
       }
       af = ntohl(tun.header.family);
 #ifndef NOINET6
-      if (af != AF_INET && (!probe.ipv6_available || af != AF_INET6))
+      if (af != AF_INET && af != AF_INET6)
 #else
       if (af != AF_INET)
 #endif
diff --git a/usr.sbin/ppp/command.c b/usr.sbin/ppp/command.c
index d8515c0..2c79b89 100644
--- a/usr.sbin/ppp/command.c
+++ b/usr.sbin/ppp/command.c
@@ -460,17 +460,15 @@ command_Expand(char **nargv, int argc, char const *const *oargv,
     nargv[arg] = subst(nargv[arg], "HISADDR",
                        inet_ntoa(bundle->ncp.ipcp.peer_ip));
 #ifndef NOINET6
-    if (probe.ipv6_available)
-      nargv[arg] = subst(nargv[arg], "HISADDR6",
-                         ncpaddr_ntoa(&bundle->ncp.ipv6cp.hisaddr));
+    nargv[arg] = subst(nargv[arg], "HISADDR6",
+                       ncpaddr_ntoa(&bundle->ncp.ipv6cp.hisaddr));
 #endif
     nargv[arg] = subst(nargv[arg], "AUTHNAME", bundle->cfg.auth.name);
     nargv[arg] = subst(nargv[arg], "INTERFACE", bundle->iface->name);
     nargv[arg] = subst(nargv[arg], "MYADDR", inet_ntoa(bundle->ncp.ipcp.my_ip));
 #ifndef NOINET6
-    if (probe.ipv6_available)
-      nargv[arg] = subst(nargv[arg], "MYADDR6",
-                         ncpaddr_ntoa(&bundle->ncp.ipv6cp.myaddr));
+    nargv[arg] = subst(nargv[arg], "MYADDR6",
+                       ncpaddr_ntoa(&bundle->ncp.ipv6cp.myaddr));
 #endif
     nargv[arg] = subst(nargv[arg], "USER", bundle->ncp.mp.peer.authname);
     nargv[arg] = subst(nargv[arg], "PEER_ENDDISC",
@@ -2342,8 +2340,7 @@ AddCommand(struct cmdargs const *arg)
     ncpaddr_setip4(&gw, arg->bundle->ncp.ipcp.peer_ip);
     addrs |= ROUTE_GWHISADDR;
 #ifndef NOINET6
-  } else if (probe.ipv6_available &&
-             strcasecmp(arg->argv[arg->argn + gw_arg], "HISADDR6") == 0) {
+  } else if (strcasecmp(arg->argv[arg->argn + gw_arg], "HISADDR6") == 0) {
     ncpaddr_copy(&gw, &arg->bundle->ncp.ipv6cp.hisaddr);
     addrs |= ROUTE_GWHISADDR6;
 #endif
@@ -2382,8 +2379,7 @@ DeleteCommand(struct cmdargs const *arg)
         ncprange_setip4host(&dest, arg->bundle->ncp.ipcp.my_ip);
         addrs = ROUTE_DSTMYADDR;
 #ifndef NOINET6
-      } else if (probe.ipv6_available &&
-                 strcasecmp(arg->argv[arg->argn], "MYADDR6") == 0) {
+      } else if (strcasecmp(arg->argv[arg->argn], "MYADDR6") == 0) {
         ncprange_sethost(&dest, &arg->bundle->ncp.ipv6cp.myaddr);
         addrs = ROUTE_DSTMYADDR6;
 #endif
@@ -2391,8 +2387,7 @@ DeleteCommand(struct cmdargs const *arg)
         ncprange_setip4host(&dest, arg->bundle->ncp.ipcp.peer_ip);
         addrs = ROUTE_DSTHISADDR;
 #ifndef NOINET6
-      } else if (probe.ipv6_available &&
-                 strcasecmp(arg->argv[arg->argn], "HISADDR6") == 0) {
+      } else if (strcasecmp(arg->argv[arg->argn], "HISADDR6") == 0) {
         ncprange_sethost(&dest, &arg->bundle->ncp.ipv6cp.hisaddr);
         addrs = ROUTE_DSTHISADDR6;
 #endif
@@ -2877,11 +2872,8 @@ ClearCommand(struct cmdargs const *arg)
   } else if (strcasecmp(arg->argv[arg->argn], "ipcp") == 0)
     t = &arg->bundle->ncp.ipcp.throughput;
 #ifndef NOINET6
-  else if (strcasecmp(arg->argv[arg->argn], "ipv6cp") == 0) {
-    if (!probe.ipv6_available)
-      return 0;
+  else if (strcasecmp(arg->argv[arg->argn], "ipv6cp") == 0)
     t = &arg->bundle->ncp.ipv6cp.throughput;
-  }
 #endif
   else
     return -1;
@@ -3027,11 +3019,8 @@ IfaceClearCommand(struct cmdargs const *arg)
     if (strcasecmp(arg->argv[arg->argn], "inet") == 0)
       family = AF_INET;
 #ifndef NOINET6
-    else if (strcasecmp(arg->argv[arg->argn], "inet6") == 0) {
-      if (!probe.ipv6_available)
-        return 0;
+    else if (strcasecmp(arg->argv[arg->argn], "inet6") == 0)
       family = AF_INET6;
-    }
 #endif
     else
       return -1;
diff --git a/usr.sbin/ppp/fsm.c b/usr.sbin/ppp/fsm.c
index 9f4cc0c..47bcd68 100644
--- a/usr.sbin/ppp/fsm.c
+++ b/usr.sbin/ppp/fsm.c
@@ -68,7 +68,6 @@
 #include "async.h"
 #include "physical.h"
 #include "proto.h"
-#include "probe.h"
 
 static void FsmSendConfigReq(struct fsm *);
 static void FsmSendTerminateReq(struct fsm *);
@@ -897,7 +896,7 @@ FsmRecvProtoRej(struct fsm *fp, struct fsmheader *lhp, struct mbuf *bp)
     break;
 #ifndef NOINET6
   case PROTO_IPV6CP:
-    if (probe.ipv6_available && fp->proto == PROTO_LCP) {
+    if (fp->proto == PROTO_LCP) {
       log_Printf(LogPHASE, "%s: IPV6CP protocol reject closes IPV6CP !\n",
                 fp->link->name);
       fsm_Close(&fp->bundle->ncp.ipv6cp.fsm);
diff --git a/usr.sbin/ppp/ip.c b/usr.sbin/ppp/ip.c
index 38f5ed2..30b6cb6 100644
--- a/usr.sbin/ppp/ip.c
+++ b/usr.sbin/ppp/ip.c
@@ -79,7 +79,6 @@
 #include "ncp.h"
 #include "bundle.h"
 #include "tun.h"
-#include "probe.h"
 
 
 #define OPCODE_QUERY	0
@@ -942,7 +941,7 @@ ipv6_Input(struct bundle *bundle, struct link *l, struct mbuf *bp)
 {
   int nb;
 
-  if (!probe.ipv6_available || bundle->ncp.ipv6cp.fsm.state != ST_OPENED) {
+  if (bundle->ncp.ipv6cp.fsm.state != ST_OPENED) {
     log_Printf(LogWARN, "ipv6_Input: IPV6CP not open - packet dropped\n");
     m_freem(bp);
     return NULL;
diff --git a/usr.sbin/ppp/ipv6cp.c b/usr.sbin/ppp/ipv6cp.c
index 5067997..9a8c2e8 100644
--- a/usr.sbin/ppp/ipv6cp.c
+++ b/usr.sbin/ppp/ipv6cp.c
@@ -187,11 +187,15 @@ ipv6cp_Init(struct ipv6cp *ipv6cp, struct bundle *bundle, struct link *l,
   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)
+  if (probe.ipv6_available) {
+    n = 100;
+    while (n &&
+           !ipcp_SetIPv6address(ipv6cp, ipv6cp->my_token, ipv6cp->peer_token)) {
       n--;
+      while (n && (ipv6cp->my_token = GenerateToken()) == ipv6cp->peer_token)
+        n--;
+    }
+  }
 
   throughput_init(&ipv6cp->throughput, SAMPLE_PERIOD);
   memset(ipv6cp->Queue, '\0', sizeof ipv6cp->Queue);
@@ -225,11 +229,6 @@ 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) {
@@ -257,7 +256,7 @@ 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)
+  if (bundle_Phase(bundle) == PHASE_NETWORK)
     fsm_Input(&bundle->ncp.ipv6cp.fsm, bp);
   else {
     if (bundle_Phase(bundle) < PHASE_NETWORK)
@@ -555,9 +554,11 @@ ipv6cp_DecodeConfig(struct fsm *fp, u_char *cp, int plen, int mode_type,
                     "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 && !ipcp_SetIPv6address(ipv6cp, token, ipv6cp->peer_token)) {
+            n--;
             while (n && (token = GenerateToken()) == ipv6cp->peer_token)
               n--;
+          }
 
           if (n == 0) {
 	    log_Printf(log_IsKept(LogIPV6CP) ? LogIPV6CP : LogPHASE,
diff --git a/usr.sbin/ppp/ncp.c b/usr.sbin/ppp/ncp.c
index 8a88800..a68c91f 100644
--- a/usr.sbin/ppp/ncp.c
+++ b/usr.sbin/ppp/ncp.c
@@ -90,7 +90,6 @@
 #include "pap.h"
 #include "cbcp.h"
 #include "datalink.h"
-#include "probe.h"
 
 
 static u_short default_urgent_tcp_ports[] = {
@@ -134,9 +133,8 @@ ncp_Init(struct ncp *ncp, struct bundle *bundle)
   ipcp_Init(&ncp->ipcp, bundle, &bundle->links->physical->link,
             &bundle->fsm);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    ipv6cp_Init(&ncp->ipv6cp, bundle, &bundle->links->physical->link,
-                &bundle->fsm);
+  ipv6cp_Init(&ncp->ipv6cp, bundle, &bundle->links->physical->link,
+              &bundle->fsm);
 #endif
 }
 
@@ -145,8 +143,7 @@ ncp_Destroy(struct ncp *ncp)
 {
   ipcp_Destroy(&ncp->ipcp);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    ipv6cp_Destroy(&ncp->ipv6cp);
+  ipv6cp_Destroy(&ncp->ipv6cp);
 #endif
 
   if (ncp->cfg.urgent.tcp.maxports) {
@@ -175,7 +172,7 @@ ncp_fsmStart(struct ncp *ncp, struct bundle *bundle)
 #ifndef NOINET6
   }
 
-  if (probe.ipv6_available && Enabled(bundle, OPT_IPV6CP)) {
+  if (Enabled(bundle, OPT_IPV6CP)) {
     fsm_Up(&ncp->ipv6cp.fsm);
     fsm_Open(&ncp->ipv6cp.fsm);
     res++;
@@ -212,8 +209,7 @@ ncp_SetLink(struct ncp *ncp, struct link *l)
 {
   ipcp_SetLink(&ncp->ipcp, l);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    ipv6cp_SetLink(&ncp->ipv6cp, l);
+  ipv6cp_SetLink(&ncp->ipv6cp, l);
 #endif
 }
 
@@ -281,8 +277,7 @@ ncp_QueueLen(struct ncp *ncp)
 
   result = ipcp_QueueLen(&ncp->ipcp);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    result += ipv6cp_QueueLen(&ncp->ipv6cp);
+  result += ipv6cp_QueueLen(&ncp->ipv6cp);
 #endif
   result += mp_QueueLen(&ncp->mp);	/* Usually empty */
 
@@ -309,10 +304,9 @@ ncp_DeleteQueues(struct ncp *ncp)
       m_freem(m_dequeue(q));
 
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    for (q = ipv6cp->Queue; q < ipv6cp->Queue + IPV6CP_QUEUES(ipv6cp); q++)
-      while (q->top)
-        m_freem(m_dequeue(q));
+  for (q = ipv6cp->Queue; q < ipv6cp->Queue + IPV6CP_QUEUES(ipv6cp); q++)
+    while (q->top)
+      m_freem(m_dequeue(q));
 #endif
 
   link_DeleteQueue(&mp->link);	/* Usually empty anyway */
@@ -358,9 +352,7 @@ ncp_PushPacket(struct ncp *ncp, int *af, struct link *l)
   int res;
 
 #ifndef NOINET6
-  if (!probe.ipv6_available)
-    res = ipcp_PushPacket(&bundle->ncp.ipcp, l);
-  else if (*af == AF_INET) {
+  if (*af == AF_INET) {
     if ((res = ipcp_PushPacket(&bundle->ncp.ipcp, l)))
       *af = AF_INET6;
     else
@@ -456,9 +448,8 @@ ncp_Show(struct cmdargs const *arg)
   int p;
 
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    prompt_Printf(arg->prompt, "Next queued AF: %s\n",
-                  ncp->afq == AF_INET6 ? "inet6" : "inet");
+  prompt_Printf(arg->prompt, "Next queued AF: %s\n",
+                ncp->afq == AF_INET6 ? "inet6" : "inet");
 #endif
 
   if (ncp->route) {
@@ -511,8 +502,7 @@ ncp_LayersOpen(struct ncp *ncp)
 
   n = !!(ncp->ipcp.fsm.state == ST_OPENED);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    n += !!(ncp->ipv6cp.fsm.state == ST_OPENED);
+  n += !!(ncp->ipv6cp.fsm.state == ST_OPENED);
 #endif
 
   return n;
@@ -528,10 +518,9 @@ ncp_LayersUnfinished(struct ncp *ncp)
     n++;
 
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    if (ncp->ipv6cp.fsm.state > ST_CLOSED ||
-        ncp->ipv6cp.fsm.state == ST_STARTING)
-      n++;
+  if (ncp->ipv6cp.fsm.state > ST_CLOSED ||
+      ncp->ipv6cp.fsm.state == ST_STARTING)
+    n++;
 #endif
 
   return n;
@@ -545,10 +534,9 @@ ncp_Close(struct ncp *ncp)
     fsm_Close(&ncp->ipcp.fsm);
 
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    if (ncp->ipv6cp.fsm.state > ST_CLOSED ||
-        ncp->ipv6cp.fsm.state == ST_STARTING)
-      fsm_Close(&ncp->ipv6cp.fsm);
+  if (ncp->ipv6cp.fsm.state > ST_CLOSED ||
+      ncp->ipv6cp.fsm.state == ST_STARTING)
+    fsm_Close(&ncp->ipv6cp.fsm);
 #endif
 }
 
@@ -557,7 +545,6 @@ ncp2initial(struct ncp *ncp)
 {
   fsm2initial(&ncp->ipcp.fsm);
 #ifndef NOINET6
-  if (probe.ipv6_available)
-    fsm2initial(&ncp->ipv6cp.fsm);
+  fsm2initial(&ncp->ipv6cp.fsm);
 #endif
 }