src/patches/dnsmasq/015-Handle_v4-mapped_IPv6_addresses_sanely_for_--synth-domain.patch

   1 From 6d95099c56a926d672e0407d6017fef9714f40c4 Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Thu, 11 Aug 2016 23:38:54 +0100
   4 Subject: [PATCH] Handle v4-mapped IPv6 addresses sanely for --synth-domain.
   5
   6 ---
   7  CHANGELOG     |    7 ++++++-
   8  man/dnsmasq.8 |    2 ++
   9  src/domain.c  |   34 ++++++++++++++++++++++++----------
  10  3 files changed, 32 insertions(+), 11 deletions(-)
  11
  12 diff --git a/CHANGELOG b/CHANGELOG
  13 index 4f89799..2731cc4 100644
  14 --- a/CHANGELOG
  15 +++ b/CHANGELOG
  16 @@ -24,7 +24,12 @@ version 2.77
  17             Bump zone serial on reloading /etc/hosts and friends
  18             when providing authoritative DNS. Thanks to Harrald
  19             Dunkel for spotting this.
  20 -
  21 +
  22 +           Handle v4-mapped IPv6 addresses sanely in --synth-domain.
  23 +           These have standard representation like ::ffff:1.2.3.4
  24 +           and are now converted to names like
  25 +           <prefix>--ffff-1-2-3-4.<domain>
  26 +
  27
  28  version 2.76
  29              Include 0.0.0.0/8 in DNS rebind checks. This range
  30 diff --git a/man/dnsmasq.8 b/man/dnsmasq.8
  31 index 8910947..91fe672 100644
  32 --- a/man/dnsmasq.8
  33 +++ b/man/dnsmasq.8
  34 @@ -619,6 +619,8 @@ but IPv6 addresses may start with '::'
  35  but DNS labels may not start with '-' so in this case if no prefix is
  36  configured a zero is added in front of the label. ::1 becomes 0--1.
  37
  38 +V4 mapped IPv6 addresses, which have a representation like ::ffff:1.2.3.4 are handled specially, and become like 0--ffff-1-2-3-4
  39 +
  40  The address range can be of the form
  41  <ip address>,<ip address> or <ip address>/<netmask>
  42  .TP
  43 diff --git a/src/domain.c b/src/domain.c
  44 index 1dd5027..a007acd 100644
  45 --- a/src/domain.c
  46 +++ b/src/domain.c
  47 @@ -77,18 +77,31 @@ int is_name_synthetic(int flags, char *name, struct all_addr *addr)
  48
  49        *p = 0;
  50
  51 -      /* swap . or : for - */
  52 -      for (p = tail; *p; p++)
  53 -       if (*p == '-')
  54 -         {
  55 -           if (prot == AF_INET)
  56 + #ifdef HAVE_IPV6
  57 +      if (prot == AF_INET6 && strstr(tail, "--ffff-") == tail)
  58 +       {
  59 +         /* special hack for v4-mapped. */
  60 +         memcpy(tail, "::ffff:", 7);
  61 +         for (p = tail + 7; *p; p++)
  62 +           if (*p == '-')
  63               *p = '.';
  64 +       }
  65 +      else
  66 +#endif
  67 +       {
  68 +         /* swap . or : for - */
  69 +         for (p = tail; *p; p++)
  70 +           if (*p == '-')
  71 +             {
  72 +               if (prot == AF_INET)
  73 +                 *p = '.';
  74  #ifdef HAVE_IPV6
  75 -           else
  76 -             *p = ':';
  77 +               else
  78 +                 *p = ':';
  79  #endif
  80 -         }
  81 -
  82 +             }
  83 +       }
  84 +
  85        if (hostname_isequal(c->domain, p+1) && inet_pton(prot, tail, addr))
  86         {
  87           if (prot == AF_INET)
  88 @@ -169,8 +182,9 @@ int is_rev_synth(int flag, struct all_addr *addr, char *name)
  89            inet_ntop(AF_INET6, &addr->addr.addr6, name+1, ADDRSTRLEN);
  90          }
  91
  92 +       /* V4-mapped have periods.... */
  93         for (p = name; *p; p++)
  94 -        if (*p == ':')
  95 +        if (*p == ':' || *p == '.')
  96            *p = '-';
  97
  98         strncat(name, ".", MAXDNAME);
  99 --
 100 1.7.10.4
 101