Add s6dns_hosts reading functions

Signed-off-by: Laurent Bercot <ska@appnovation.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/src/libs6dns/s6dns_hosts_name.c b/src/libs6dns/s6dns_hosts_name.c
new file mode 100644
index 0000000..af2030b
--- /dev/null
+++ b/src/libs6dns/s6dns_hosts_name.c
@@ -0,0 +1,43 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <string.h>
+
+#include <skalibs/cdb.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/genalloc.h>
+
+#include <s6-dns/hosts.h>
+
+#include <skalibs/posixishard.h>
+
+int s6dns_hosts_name_r (cdb const *c, char const *ip, stralloc *sa, genalloc *ga, int is6)
+{
+  int r ;
+  cdb_data data ;
+  int sawn = !sa->s ;
+  int gawn = !genalloc_s(size_t, ga) ;
+  size_t sabase = sa->len ;
+  size_t gabase = genalloc_len(size_t, ga) ;
+  size_t i = sabase ;
+  char tmp[19] = "p4:" ;
+  if (!c->map) return 0 ;
+  if (is6) tmp[1] = '6' ;
+  memcpy(tmp + 3, ip, is6 ? 16 : 4) ;
+  r = cdb_find(c, &data, tmp, 7) ;
+  if (r <= 0) return r ;
+  if (!data.len) return 0 ;
+  if (data.s[data.len - 1]) return (errno = EPROTO, -1) ;
+  if (!stralloc_catb(sa, data.s, data.len)) return -1 ;
+  while (i < sa->len)
+  {
+    if (!genalloc_catb(size_t, ga, &i, 1)) goto err ;
+    i += strlen(sa->s + i) + 1 ;
+  }
+  return genalloc_len(size_t, ga) - gabase ;
+
+ err:
+  if (gawn) genalloc_free(size_t, ga) ; else genalloc_setlen(size_t, ga, 0) ;
+  if (sawn) stralloc_free(sa) ; else sa->len = 0 ;
+  return -1 ;
+}