initial commit of version 23fehQlibs-23

1 files changed, 236 insertions, 0 deletions

diff --git a/dnsstub/dns_ipq.c b/dnsstub/dns_ipq.c
new file mode 100644
index 0000000..26c3818
--- /dev/null
+++ b/dnsstub/dns_ipq.c
@@ -0,0 +1,236 @@
+#include "case.h"
+#include "byte.h"
+#include "str.h"
+#include "stralloc.h"
+#include "dnsresolv.h"
+#include "socket_if.h"
+#include "ip.h"
+
+/**
+	@file dns_ipq.c	
+	@author djb, feh
+	@source ucspi-tcp
+	@brief DNS hostname qualification for ipv4 and ipv6
+*/
+
+/** 
+  @fn int doit -> @return number of added chars to name 
+*/
+static int doit(stralloc *work,const char *rule)
+{
+  char ch;
+  unsigned int colon;
+  unsigned int prefixlen;
+
+  ch = *rule++;
+  if ((ch != '?') && (ch != '=') && (ch != '*') && (ch != '-')) return 1;
+  colon = str_chr((char *)rule,':');
+  if (!rule[colon]) return 1;
+
+  if (work->len < colon) return 1;
+  prefixlen = work->len - colon;
+  if ((ch == '=') && prefixlen) return 1;
+  if (case_diffb((char *)rule,colon,work->s + prefixlen)) return 1;
+  if (ch == '?') {
+    if (byte_chr(work->s,prefixlen,'.') < prefixlen) return 1;
+    if (byte_chr(work->s,prefixlen,'[') < prefixlen) return 1;
+    if (byte_chr(work->s,prefixlen,']') < prefixlen) return 1;
+  }
+
+  work->len = prefixlen;
+  if (ch == '-') work->len = 0;
+  return stralloc_cats(work,rule + colon + 1);
+}
+
+/** @fn  int dns_ip4_qualify_rules -> @return number of IPv4 addresss with rules */
+
+int dns_ip4_qualify_rules(stralloc *ipout,stralloc *fqdn,const stralloc *in,const stralloc *rules)
+{
+  unsigned int i;
+  unsigned int j;
+  unsigned int plus;
+  unsigned int fqdnlen;
+  int rc = 0;
+
+  if (!stralloc_copy(fqdn,(stralloc *)in)) return DNS_MEM;
+
+  for (j = i = 0; j < rules->len; ++j)
+    if (!rules->s[j]) {
+      if (!doit(fqdn,rules->s + i)) return DNS_INT;
+      i = j + 1;
+    }
+
+  fqdnlen = fqdn->len;
+  plus = byte_chr(fqdn->s,fqdnlen,'+');
+  if (plus >= fqdnlen)
+    return dns_ip4(ipout,fqdn);
+
+  i = plus + 1;
+  for (;;) {
+    j = byte_chr(fqdn->s + i,fqdnlen - i,'+');
+    byte_copy(fqdn->s + plus,j,fqdn->s + i);
+    fqdn->len = plus + j;
+    if (rc += dns_ip4(ipout,fqdn) < 0) return DNS_ERR;
+    i += j;
+    if (i >= fqdnlen) return rc;
+    ++i;
+  }
+  return 0;
+}
+
+/** @fn  int dns_ip4_qualify -> @return number of IPv4 addresss qualified */
+
+int dns_ip4_qualify(stralloc *ipout,stralloc *fqdn,const stralloc *in)
+{
+  int r;
+  static stralloc rules;
+
+  if ((r = dns_ip_qualify_localhost(ipout,fqdn,in)) > 0 ) return r; 
+  if (dns_resolvconfrewrite(&rules) < 0) return DNS_INT;
+  return dns_ip4_qualify_rules(ipout,fqdn,in,&rules);
+}
+
+/** @fn  int dns_ip4_qualify_rules -> @return number of IPv6 addresss with rules */
+
+int dns_ip6_qualify_rules(stralloc *ipout,stralloc *fqdn,const stralloc *in,const stralloc *rules)
+{
+  unsigned int i;
+  unsigned int j;
+  unsigned int plus;
+  unsigned int fqdnlen;
+  int rc = 0; 
+
+  if (!stralloc_copy(fqdn,(stralloc *)in)) return DNS_MEM;
+
+  for (j = i = 0; j < rules->len; ++j)
+    if (!rules->s[j]) {
+      if (!doit(fqdn,rules->s + i)) return DNS_INT;
+      i = j + 1;
+    }
+
+  fqdnlen = fqdn->len;
+  plus = byte_chr(fqdn->s,fqdnlen,'+');
+  if (plus >= fqdnlen)
+    return dns_ip6(ipout,fqdn);
+
+  i = plus + 1;
+  for (;;) {
+    j = byte_chr(fqdn->s + i,fqdnlen - i,'+');
+    byte_copy(fqdn->s + plus,j,fqdn->s + i);
+    fqdn->len = plus + j;
+    if ((rc += dns_ip6(ipout,fqdn)) < 0) return DNS_ERR;
+    i += j;
+    if (i >= fqdnlen) return rc;
+    ++i;
+  }
+  return 0;
+}
+
+/** @fn  int dns_ip6_qualify -> @return number of IPv6 addresss qualified */
+
+int dns_ip6_qualify(stralloc *ipout,stralloc *fqdn,const stralloc *in)
+{
+  int r; 
+  static stralloc rules;
+  
+  if ((r = dns_ip_qualify_localhost(ipout,fqdn,in)) > 0) return r;
+  if (dns_resolvconfrewrite(&rules) < 0) return DNS_INT;
+  return dns_ip6_qualify_rules(ipout,fqdn,in,&rules);
+}
+
+/** @fn  int dns_ip_qualify_rules -> @return number of IPv6+IPv4 addresss with rules */
+
+int dns_ip_qualify_rules(stralloc *ipout,stralloc *fqdn,const stralloc *in,const stralloc *rules)
+{
+  unsigned int i;
+  unsigned int j;
+  unsigned int k;
+  unsigned int plus;
+  unsigned int fqdnlen;
+  stralloc tmp = {0};
+  int rc = 0; 
+
+  if (!stralloc_copy(fqdn,(stralloc *)in)) return DNS_MEM;
+  if (!stralloc_copys(ipout,"")) return DNS_MEM;
+
+  for (j = i = 0; j < rules->len; ++j)
+    if (!rules->s[j]) {
+      if (!doit(fqdn,rules->s + i)) return DNS_INT;
+      i = j + 1;
+    }
+
+  fqdnlen = fqdn->len;
+  plus = byte_chr(fqdn->s,fqdnlen,'+');
+  if (plus >= fqdnlen) {
+    rc = dns_ip6(ipout,fqdn);
+    if (dns_ip4(&tmp,fqdn) > 0) {
+      for (k = 0; k < tmp.len; k += 4) {
+        if (!stralloc_catb(ipout,(const char *) V4mappedprefix,12)) return DNS_MEM;
+        if (!stralloc_catb(ipout,tmp.s + k,4)) return DNS_MEM;
+        rc++;
+      }
+    }
+    return rc;
+  }
+
+  i = plus + 1;
+  for (;;) {
+    j = byte_chr(fqdn->s + i,fqdnlen - i,'+');
+    byte_copy(fqdn->s + plus,j,fqdn->s + i);
+    fqdn->len = plus + j;
+    if (!stralloc_copys(ipout,"")) return DNS_MEM;
+    rc = dns_ip6(&tmp,fqdn); 
+    if (rc) if (!stralloc_cat(ipout,&tmp)) return DNS_MEM;
+    if (dns_ip4(&tmp,fqdn) > 0) {
+      for (k = 0; k < tmp.len; k += 4) {
+        if (!stralloc_catb(ipout,(const char *) V4mappedprefix,12)) return DNS_MEM;
+        if (!stralloc_catb(ipout,tmp.s + k,4)) return DNS_MEM;
+        rc++;
+      }
+    }
+    
+    if (rc < 0) return DNS_ERR;
+    i += j;
+    if (i >= fqdnlen) return rc;
+    ++i;
+  }
+  return 0;
+}
+
+/** @fn  int dns_ip_qualify_localhost -> @return number of IP addresss */
+
+int dns_ip_qualify_localhost(stralloc *ipout,stralloc *fqdn,const stralloc *in)
+{
+  if (!stralloc_copys(ipout,"")) return DNS_MEM;
+  if (!stralloc_copys(fqdn,"")) return DNS_MEM;
+  ipout->len = 0;
+
+  if (byte_equal(in->s,9,LOCALHOST)) {
+    if (!stralloc_copyb(ipout,(const char *) V6loopback,16)) return DNS_MEM;
+    if (!stralloc_catb(ipout,(const char *) V46loopback,16)) return DNS_MEM;
+    if (!stralloc_copys(fqdn,"localhost.localhost.")) return DNS_MEM;
+  }
+  if (byte_equal(in->s,13,IP4_LOOPBACK)) {
+    if (!stralloc_copyb(ipout,(const char *) V46loopback,16)) return DNS_MEM;
+    if (!stralloc_copys(fqdn,"ip4-loopback.localhost.")) return DNS_MEM;
+  }
+  if (byte_equal(in->s,13,IP6_LOOPBACK)) {
+    if (!stralloc_copyb(ipout,(const char *) V6loopback,16)) return DNS_MEM;
+    if (!stralloc_copys(fqdn,"ip6-loopback.localhost.")) return DNS_MEM;
+  }
+//  if (!stralloc_0(fqdn)) return DNS_MEM; // don't do it
+
+  return ipout->len ? ipout->len % 15 : 0;
+}
+
+/** @fn  int dns_ip_qualify -> @return number of IP addresss */
+
+int dns_ip_qualify(stralloc *ipout,stralloc *fqdn,const stralloc *in)
+{
+  int r;
+  static stralloc rules;
+
+  if ((r = dns_ip_qualify_localhost(ipout,fqdn,in)) > 0 ) return r; 
+  if (dns_resolvconfrewrite(&rules) < 0) return DNS_INT;
+  return dns_ip_qualify_rules(ipout,fqdn,in,&rules);
+}