diff -r 262ce8533627 source/dietlibc/diet-qmail/qmail-103-oversize-dns.patch

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000

+++ b/source/dietlibc/diet-qmail/qmail-103-oversize-dns.patch	Fri May 04 20:46:20 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 u_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;

+ }

+