Imported pristine/qmail-103-oversize-dns.patch
authorTomas Zeman <tzeman@volny.cz>
Sun, 08 Jul 2012 12:20:20 +0200
changeset 4 454df9357b4b
parent 3 a7d3f30999ff
child 5 4c75df3b7bbb
Imported pristine/qmail-103-oversize-dns.patch
pristine/qmail-103-oversize-dns.patch
series
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/pristine/qmail-103-oversize-dns.patch	Sun Jul 08 12:20:20 2012 +0200
@@ -0,0 +1,71 @@
+http://www.ckdhr.com/ckd/qmail-103.patch
+
+Description from http://qmail.ruk.cuni.cz/top.html :
+Christopher K. Davis has a patch to accept oversize DNS packets which works on
+both qmail's dns.c and tcpserver's dns.c. If you don't want to patch qmail, you
+can ameliorate the problem somewhat using djbdns, which returns only the
+records you ask for, making for a smaller ANSWER section. 
+
+--- qmail-1.03/dns.c.103	Mon Aug 17 16:06:58 1998
++++ qmail-1.03/dns.c	Wed Aug 26 16:28:56 1998
+@@ -21,10 +21,12 @@
+ static unsigned short getshort(c) unsigned char *c;
+ { unsigned short u; u = c[0]; return (u << 8) + c[1]; }
+ 
+-static union { HEADER hdr; unsigned char buf[PACKETSZ]; } response;
++static struct { unsigned char *buf; } response;
++static int responsebuflen = 0;
+ static int responselen;
+ static unsigned char *responseend;
+ static unsigned char *responsepos;
++static unsigned long saveresoptions;
+ 
+ static int numanswers;
+ static char name[MAXDNAME];
+@@ -45,18 +47,33 @@
+  errno = 0;
+  if (!stralloc_copy(&glue,domain)) return DNS_MEM;
+  if (!stralloc_0(&glue)) return DNS_MEM;
+- responselen = lookup(glue.s,C_IN,type,response.buf,sizeof(response));
++ if (!responsebuflen)
++  if (response.buf = (unsigned char *)alloc(PACKETSZ+1))
++   responsebuflen = PACKETSZ+1;
++  else return DNS_MEM;
++
++ responselen = lookup(glue.s,C_IN,type,response.buf,responsebuflen);
++ if ((responselen >= responsebuflen) ||
++     (responselen > 0 && (((HEADER *)response.buf)->tc)))
++  {
++   if (responsebuflen < 65536)
++    if (alloc_re(&response.buf, responsebuflen, 65536))
++     responsebuflen = 65536;
++    else return DNS_MEM;
++    saveresoptions = _res.options;
++    _res.options |= RES_USEVC;
++    responselen = lookup(glue.s,C_IN,type,response.buf,responsebuflen);
++    _res.options = saveresoptions;
++  }
+  if (responselen <= 0)
+   {
+    if (errno == ECONNREFUSED) return DNS_SOFT;
+    if (h_errno == TRY_AGAIN) return DNS_SOFT;
+    return DNS_HARD;
+   }
+- if (responselen >= sizeof(response))
+-   responselen = sizeof(response);
+  responseend = response.buf + responselen;
+  responsepos = response.buf + sizeof(HEADER);
+- n = ntohs(response.hdr.qdcount);
++ n = ntohs(((HEADER *)response.buf)->qdcount);
+  while (n-- > 0)
+   {
+    i = dn_expand(response.buf,responseend,responsepos,name,MAXDNAME);
+@@ -66,7 +83,7 @@
+    if (i < QFIXEDSZ) return DNS_SOFT;
+    responsepos += QFIXEDSZ;
+   }
+- numanswers = ntohs(response.hdr.ancount);
++ numanswers = ntohs(((HEADER *)response.buf)->ancount);
+  return 0;
+ }
+ 
--- a/series	Thu Nov 01 16:57:27 2007 +0100
+++ b/series	Sun Jul 08 12:20:20 2012 +0200
@@ -4,4 +4,5 @@
 qregex-20060423-qmail.patch #+feature
 qmail-dietlibc.patch #+diet
 qmail-smtpd.spam.patch #+feature
+pristine/qmail-103-oversize-dns.patch
 pristine/qregex-20060423.patch #-pristine #+fail