git.openwrt.org Git - openwrt/openwrt.git/blob

   1 From 1f60a18ea1c64beb8b6cffa0650a2bfad95ac352 Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Fri, 11 May 2018 16:44:16 +0100
   4 Subject: [PATCH 07/17] Retry SERVFAIL DNSSEC queries to a different server, if
   5  possible.
   6
   7 Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
   8 ---
   9  src/forward.c | 53 ++++++++++++++++++++++++++++++++++++++++++-----------
  10  1 file changed, 42 insertions(+), 11 deletions(-)
  11
  12 --- a/src/forward.c
  13 +++ b/src/forward.c
  14 @@ -825,9 +825,12 @@ void reply_query(int fd, int family, tim
  15        size_t plen;
  16        int is_sign;
  17
  18 +#ifdef HAVE_DNSSEC
  19        /* For DNSSEC originated queries, just retry the query to the same server. */
  20        if (forward->flags & (FREC_DNSKEY_QUERY | FREC_DS_QUERY))
  21         {
  22 +         struct server *start;
  23 +
  24           blockdata_retrieve(forward->stash, forward->stash_len, (void *)header);
  25           plen = forward->stash_len;
  26
  27 @@ -839,26 +842,54 @@ void reply_query(int fd, int family, tim
  28           else
  29             log_query(F_NOEXTRA | F_DNSSEC | F_IPV6, "retry", (struct all_addr *)&forward->sentto->addr.in6.sin6_addr, "dnssec");
  30  #endif
  31 -
  32 -         if (forward->sentto->sfd)
  33 -           fd = forward->sentto->sfd->fd;
  34 +
  35 +         start = forward->sentto;
  36 +
  37 +         /* for non-domain specific servers, see if we can find another to try. */
  38 +         if ((forward->sentto->flags & SERV_TYPE) == 0)
  39 +           while (1)
  40 +             {
  41 +               if (!(start = start->next))
  42 +                 start = daemon->servers;
  43 +               if (start == forward->sentto)
  44 +                 break;
  45 +
  46 +               if ((start->flags & SERV_TYPE) == 0 &&
  47 +                   (start->flags & SERV_DO_DNSSEC))
  48 +                 break;
  49 +             }
  50 +
  51 +
  52 +         if (start->sfd)
  53 +           fd = start->sfd->fd;
  54           else
  55             {
  56  #ifdef HAVE_IPV6
  57 -             if (forward->sentto->addr.sa.sa_family == AF_INET6)
  58 -               fd = forward->rfd6->fd;
  59 +             if (start->addr.sa.sa_family == AF_INET6)
  60 +               {
  61 +                 /* may have changed family */
  62 +                 if (!forward->rfd6)
  63 +                   forward->rfd6 = allocate_rfd(AF_INET6);
  64 +                 fd = forward->rfd6->fd;
  65 +               }
  66               else
  67  #endif
  68 -               fd = forward->rfd4->fd;
  69 +               {
  70 +                 /* may have changed family */
  71 +                 if (!forward->rfd4)
  72 +                   forward->rfd4 = allocate_rfd(AF_INET);
  73 +                 fd = forward->rfd4->fd;
  74 +               }
  75             }
  76 -
  77 +
  78           while (retry_send(sendto(fd, (char *)header, plen, 0,
  79 -                                  &forward->sentto->addr.sa,
  80 -                                  sa_len(&forward->sentto->addr))));
  81 +                                  &start->addr.sa,
  82 +                                  sa_len(&start->addr))));
  83
  84           return;
  85         }
  86 -
  87 +#endif
  88 +
  89        /* In strict order mode, there must be a server later in the chain
  90          left to send to, otherwise without the forwardall mechanism,
  91          code further on will cycle around the list forwever if they
  92 @@ -1024,7 +1055,7 @@ void reply_query(int fd, int family, tim
  93                           while (1)
  94                             {
  95                               if (type == (start->flags & (SERV_TYPE | SERV_DO_DNSSEC)) &&
  96 -                                 (type != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) &&
  97 +                                 ((type & SERV_TYPE) != SERV_HAS_DOMAIN || hostname_isequal(domain, start->domain)) &&
  98                                   !(start->flags & (SERV_LITERAL_ADDRESS | SERV_LOOP)))
  99                                 {
 100                                   new_server = start;