Initial commit

1 files changed, 173 insertions, 0 deletions

diff --git a/src/libs6dns/s6dns_rci_init.c b/src/libs6dns/s6dns_rci_init.c
new file mode 100644
index 0000000..a4f3fcf
--- /dev/null
+++ b/src/libs6dns/s6dns_rci_init.c
@@ -0,0 +1,173 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/bytestr.h>
+#include <skalibs/bitarray.h>
+#include <skalibs/fmtscan.h>
+#include <skalibs/tai.h>
+#include <skalibs/djbunix.h>
+#include <skalibs/stralloc.h>
+#include <skalibs/ip46.h>
+#include <s6-dns/s6dns-constants.h>
+#include <s6-dns/s6dns-rci.h>
+
+static unsigned int readit (char const *file, char *buf, unsigned int max)
+{
+  register int r = openreadnclose(file, buf, max - 1) ;
+  if (r < 0)
+  {
+    if (errno != ENOENT) return 0 ;
+    else r = 0 ;
+  }
+  buf[r++] = '\n' ;
+  return (unsigned int)r ;
+}
+
+static inline int s6dns_rci_init_servers (s6dns_rci_t *rci, char const *file, char *tmp, unsigned int max, unsigned int *size)
+{
+  ip46_t tmplist[S6DNS_MAX_SERVERS] ;
+  unsigned int num = 0 ;
+  char const *x = env_get("DNSCACHEIP") ;
+  if (x) ip46_scanlist(tmplist, S6DNS_MAX_SERVERS, x, &num) ;
+  if (!num)
+  {
+    unsigned int i = 0 ;
+    *size = readit(file, tmp, max) ;
+    if (!*size) return 0 ;
+    while ((i < *size) && (num < S6DNS_MAX_SERVERS))
+    {
+      register unsigned int j = byte_chr(tmp + i, *size - i, '\n') ;
+      if ((i + j < *size) && (j > 13U) && !byte_diff("nameserver", 10, tmp + i))
+      {
+        register unsigned int k = 0 ;
+        while ((tmp[i+10+k] == ' ') || (tmp[i+10+k] == '\t')) k++ ;
+        if (k && ip46_scan(tmp+i+10+k, tmplist + num)) num++ ;
+      }
+      i += j + 1 ;
+    }
+  }
+  if (!num)
+  {
+    num = 1 ;
+    byte_copy(tmplist[0].ip, SKALIBS_IP_SIZE, S6DNS_LOCALHOST_IP) ;
+#ifdef SKALIBS_IPV6_ENABLED
+    tmplist[0].is6 = 1 ;
+#endif
+  }
+
+  {
+    register unsigned int i = 0 ;
+    byte_zero(&rci->servers, sizeof(s6dns_ip46list_t)) ;
+    for (; i < num ; i++)
+    {
+      byte_copy(rci->servers.ip + SKALIBS_IP_SIZE * i, SKALIBS_IP_SIZE, tmplist[i].ip) ;
+#ifdef SKALIBS_IPV6_ENABLED
+      if (ip46_is6(tmplist+i)) bitarray_set(rci->servers.is6, i) ;
+#endif
+    }
+  }
+  return 1 ;
+}
+
+static inline int stringrules (stralloc *rules, char const *s, unsigned int *num)
+{
+  unsigned int n = 0 ;
+  int crunching = 1 ;
+  int wasnull = !rules->s ;
+  unsigned int base = rules->len ;
+  char c = ' ' ;
+  while (c)
+  {
+    c = *s++ ;
+    if (byte_chr(" \t\n\r", 5, c) < 5)
+    {
+      if (!crunching)
+      {
+        if ((rules->s[rules->len - 1] != '.') && !stralloc_catb(rules, ".", 1)) goto err ;
+        if (!stralloc_0(rules)) goto err ;
+        n++ ;
+        crunching = 1 ;
+      }
+    }
+    else
+    {
+      if (crunching) crunching = 0 ;
+      if (!stralloc_catb(rules, &c, 1)) goto err ;
+    }
+  }
+  *num += n ;
+  return 1 ;
+
+ err:
+  if (wasnull) stralloc_free(rules) ;
+  else rules->len = base ;
+  return 0 ;
+}
+
+static inline int s6dns_rci_init_rules (s6dns_rci_t_ref rci, char const *file, char *tmp, unsigned int max, unsigned int *size)
+{
+  unsigned int num = 0 ;
+  char const *x = env_get("DNSQUALIFY") ;
+  if (x)
+  {
+    if (!stringrules(&rci->rules, x, &num)) return 0 ;
+  }
+  else
+  {
+    unsigned int i = 0 ;
+    if (!*size)
+    {
+      *size = readit(file, tmp, max) ;
+      if (!*size) return 0 ;
+    }
+    while (i < *size)
+    {
+      register unsigned int j = byte_chr(tmp + i, *size - i, '\n') ;
+      if ((i + j < *size) && (j > 8U)
+       && (!byte_diff("domain", 6, tmp + i) || !byte_diff("search", 6, tmp + i))
+       && ((tmp[i+6] == ' ') || (tmp[i+6] == '\t') || (tmp[i+6] == '\r')))
+      {
+        unsigned int k = 0 ;
+        int copying = 0 ;
+        register int notsearching = (tmp[i] != 's') ;
+        if (!stralloc_readyplus(&rci->rules, j)) return 0 ;
+        for (; 6 + k < j ; k++)
+        {
+          char c = tmp[i+7+k] ;
+          if ((c == ' ') || (c == '\t') || (c == '\r') || (c == '\n'))
+          {
+            if (copying)
+            {
+              copying = 0 ;
+              if ((tmp[i+6+k] != '.') && !stralloc_catb(&rci->rules, ".", 1)) return 0 ;
+              if (!stralloc_0(&rci->rules)) return 0 ;
+              num++ ;
+              if (notsearching) break ;
+            }
+          }
+          else
+          {
+            copying = 1 ;
+            if (!stralloc_catb(&rci->rules, &c, 1)) return 0 ;
+          }
+        }
+      }
+      i += j + 1 ;
+    }
+  }
+  if (!stralloc_0(&rci->rules)) return 0 ; /* empty rule to finish */
+  num++ ;
+  rci->rulesnum = num ;
+  stralloc_shrink(&rci->rules) ;
+  return 1 ;
+}
+
+int s6dns_rci_init (s6dns_rci_t *rci, char const *file)
+{
+  char tmp[4096] ;
+  unsigned int size = 0 ;
+  if (!s6dns_rci_init_servers(rci, file, tmp, 4096, &size)) return 0 ;
+  if (!s6dns_rci_init_rules(rci, file, tmp, 4096, &size)) return 0 ;
+  return 1 ;
+}