1 files changed, 52 insertions, 0 deletions
diff --git a/src/clients/s6-dnsip4-filter.c b/src/clients/s6-dnsip4-filter.c
new file mode 100644
index 0000000..6d6862e
--- /dev/null
+++ b/src/clients/s6-dnsip4-filter.c
@@ -0,0 +1,52 @@
+/* ISC license. */
+
+#include <skalibs/bytestr.h>
+#include <skalibs/fmtscan.h>
+#include <skalibs/strerr2.h>
+#include <skalibs/stralloc.h>
+#include <s6-dns/s6dns-constants.h>
+#include <s6-dns/s6dns-message.h>
+#include "s6dns-generic-filter.h"
+
+#define USAGE "s6-dnsip4-filter [ -l lines ] [ -c concurrency ] [ -t timeout ] [ -f format ] [ -e errorformat ]"
+
+typedef struct s6dns_a1_s s6dns_a1_t, *s6dns_a1_t_ref ;
+struct s6dns_a1_s
+{
+  char ip[4] ;
+  unsigned int got : 1 ;
+} ;
+
+static int s6dns_message_parse_answer_a1 (s6dns_message_rr_t const *rr, char const *packet, unsigned int packetlen, unsigned int pos, unsigned int section, void *stuff)
+{
+  if ((section == 2) && (rr->rtype == S6DNS_T_A) && (rr->rdlength == 4))
+  {
+    s6dns_a1_t *data = stuff ;
+    if (data->got) return 1 ;
+    byte_copy(data->ip, 4, packet+pos) ;
+    data->got = 1 ;
+  }
+  (void)packetlen ;
+  return 1 ;
+}
+
+static int ipformatter (stralloc *sa, char const *packet, unsigned int packetlen)
+{
+  s6dns_a1_t data ;
+  s6dns_message_header_t h ;
+  register int r ;
+  data.got = 0 ;
+  r = s6dns_message_parse(&h, packet, packetlen, &s6dns_message_parse_answer_a1, &data) ;
+  if (r <= 0) return r ;
+  if (!data.got) return 1 ;
+  if (!stralloc_readyplus(sa, IP4_FMT)) return -1 ;
+  sa->len += ip4_fmt(sa->s + sa->len, data.ip) ;
+  stralloc_0(sa) ;
+  return 1 ;
+}
+
+int main (int argc, char const *const *argv, char const *const *envp)
+{
+  PROG = "s6-dnsip4-filter" ;
+  return s6dns_generic_filter_main(argc, argv, envp, S6DNS_T_A, &s6dns_namescanner, &ipformatter, USAGE) ;
+}