Hi,

I don't think that adding a -4 option for ipv4 is a good idea.
This would collide with NFS Version 4, whenever we get it.

Bernd

On Tue, May 01, 2001 at 12:28:00PM -0700, adam@algroup.co.uk wrote:
> 
> >Number:         12802
> >Category:       bin
> >Synopsis:       mount_nfs forces ipv6 if interface is capable
> >Confidential:   no
> >Severity:       serious
> >Priority:       medium
> >Responsible:    bin-bug-people
> >State:          open
> >Class:          sw-bug
> >Submitter-Id:   net
> >Arrival-Date:   Tue May 01 12:28:00 PDT 2001
> >Closed-Date:
> >Last-Modified:
> >Originator:     Adam Laurie
> >Release:        1.5
> >Organization:
> A.L. Digital Ltd.
> >Environment:
> NetBSD gnugget 1.5U NetBSD 1.5U (GNUGGET) #16: Mon Apr 30 15:52:55 BST 2001     root@gnugget:/usr/src/sys/arch/hpcmips/compile/GNUGGET hpcmips
> 
> >Description:
> mount_nfs will choose ipv6 for the rpcbind request if the interface is 
> capable. this will cause it to fail for services that are only registered 
> for ipv4.
> >How-To-Repeat:
> build cfsd (with port 2049 option), run rpcbind, mountd and cfsd. 
> you then get the following behaviour:
> 
>   gnugget-root# /sbin/mount -o intr,-2 localhost:/null /crypt
>   mount_nfs: rpcbind on server: RPC: Program not registered
> 
> adding the option to specify ipv4 fixes it:
> 
>   gnugget-root# /sbin/mount -o intr,-2,-4 localhost:/null /crypt
>   gnugget-root# 
> 
> >Fix:
> apply the following patch:
> 
> --- sbin/mount_nfs/mount_nfs.c.orig     Mon Apr 30 14:38:55 2001
> +++ sbin/mount_nfs/mount_nfs.c  Mon Apr 30 14:46:27 2001
> @@ -168,6 +168,7 @@
>  int nfsproto = IPPROTO_UDP;
>  int force2 = 0;
>  int force3 = 0;
> +int inet4 = 0;
>  int mnttcp_ok = 1;
>  
>  #ifdef NFSKERB
> @@ -237,7 +238,7 @@
>         nfsargs = nfsdefargs;
>         nfsargsp = &nfsargs;
>         while ((c = getopt(argc, argv,
> -           "23a:bcCdD:g:I:iKL:lm:o:PpqR:r:sTt:w:x:UX")) != -1)
> +           "234a:bcCdD:g:I:iKL:lm:o:PpqR:r:sTt:w:x:UX")) != -1)
>                 switch (c) {
>                 case '3':
>                         if (force2)
> @@ -250,6 +251,9 @@
>                         force2 = 1;
>                         nfsargsp->flags &= ~NFSMNT_NFSV3;
>                         break;
> +               case '4':
> +                       inet4 = 1;
> +                       break;
>                 case 'a':
>                         num = strtol(optarg, &p, 10);
>                         if (*p || num < 0)
> @@ -672,12 +676,12 @@
>          * __rpc_*2nconf exist, maybe they should be exported.
>          */
>         if (nfsargsp->sotype == SOCK_STREAM) {
> -               if (ai->ai_family == AF_INET6)  
> +               if (ai->ai_family == AF_INET6 && ! inet4)       
>                         netid = "tcp6";
>                 else
>                         netid = "tcp";
>         } else {
> -               if (ai->ai_family == AF_INET6)
> +               if (ai->ai_family == AF_INET6 && ! inet4)
>                         netid = "udp6";
>                 else
>                         netid = "udp";
> @@ -857,7 +861,7 @@
>  usage()
>  {
>         (void)fprintf(stderr, "usage: mount_nfs %s\n%s\n%s\n%s\n%s\n",
> -"[-23bcCdiKlpPqsTUX] [-a maxreadahead] [-D deadthresh]",
> +"[-234bcCdiKlpPqsTUX] [-a maxreadahead] [-D deadthresh]",
>  "\t[-g maxgroups] [-I readdirsize] [-L leaseterm] [-m realm]",
>  "\t[-o options] [-R retrycnt] [-r readsize] [-t timeout]",
>  "\t[-w writesize] [-x retrans]",
> --- sbin/mount_nfs/mount_nfs.8.orig     Mon Apr 30 15:36:52 2001
> +++ sbin/mount_nfs/mount_nfs.8  Mon Apr 30 15:36:58 2001
> @@ -42,7 +42,7 @@
>  .Sh SYNOPSIS
>  .Nm ""
>  .Bk -words
> -.Op Fl 23KPTUbcCdilqs
> +.Op Fl 234KPTUbcCdilqs
>  .Ek
>  .Bk -words
>  .Op Fl D Ar deadthresh
> @@ -103,6 +103,8 @@
>  .It Fl 3
>  Use the NFS Version 3 protocol. The default is to try version 3 first, and
>  fall back to version 2 if the mount fails.
> +.It Fl 4
> +Use IPv4 transport. The default is to use IPv6 if the interface supports it.
>  .It Fl D
>  Used with NQNFS to set the
>  .Dq "dead server threshold"
> 
> >Release-Note:
> >Audit-Trail:
> >Unformatted:
>