qmail/sme9/qmail-103-dns_response_buffer.patch

--- 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;
 }
 
1	slords	1.1	--- qmail-1.03/dns.c.103 Mon Aug 17 16:06:58 1998
2			+++ qmail-1.03/dns.c Wed Aug 26 16:28:56 1998
3			@@ -21,10 +21,12 @@
4			static unsigned short getshort(c) unsigned char *c;
5			{ unsigned short u; u = c[0]; return (u << 8) + c[1]; }
6
7			-static union { HEADER hdr; unsigned char buf[PACKETSZ]; } response;
8			+static struct { unsigned char *buf; } response;
9			+static int responsebuflen = 0;
10			static int responselen;
11			static unsigned char *responseend;
12			static unsigned char *responsepos;
13			+static u_long saveresoptions;
14
15			static int numanswers;
16			static char name[MAXDNAME];
17			@@ -45,18 +47,33 @@
18			errno = 0;
19			if (!stralloc_copy(&glue,domain)) return DNS_MEM;
20			if (!stralloc_0(&glue)) return DNS_MEM;
21			- responselen = lookup(glue.s,C_IN,type,response.buf,sizeof(response));
22			+ if (!responsebuflen)
23			+ if (response.buf = (unsigned char *)alloc(PACKETSZ+1))
24			+ responsebuflen = PACKETSZ+1;
25			+ else return DNS_MEM;
26			+
27			+ responselen = lookup(glue.s,C_IN,type,response.buf,responsebuflen);
28			+ if ((responselen >= responsebuflen) \|\|
29			+ (responselen > 0 && (((HEADER *)response.buf)->tc)))
30			+ {
31			+ if (responsebuflen < 65536)
32			+ if (alloc_re(&response.buf, responsebuflen, 65536))
33			+ responsebuflen = 65536;
34			+ else return DNS_MEM;
35			+ saveresoptions = _res.options;
36			+ _res.options \|= RES_USEVC;
37			+ responselen = lookup(glue.s,C_IN,type,response.buf,responsebuflen);
38			+ _res.options = saveresoptions;
39			+ }
40			if (responselen <= 0)
41			{
42			if (errno == ECONNREFUSED) return DNS_SOFT;
43			if (h_errno == TRY_AGAIN) return DNS_SOFT;
44			return DNS_HARD;
45			}
46			- if (responselen >= sizeof(response))
47			- responselen = sizeof(response);
48			responseend = response.buf + responselen;
49			responsepos = response.buf + sizeof(HEADER);
50			- n = ntohs(response.hdr.qdcount);
51			+ n = ntohs(((HEADER *)response.buf)->qdcount);
52			while (n-- > 0)
53			{
54			i = dn_expand(response.buf,responseend,responsepos,name,MAXDNAME);
55			@@ -66,7 +83,7 @@
56			if (i < QFIXEDSZ) return DNS_SOFT;
57			responsepos += QFIXEDSZ;
58			}
59			- numanswers = ntohs(response.hdr.ancount);
60			+ numanswers = ntohs(((HEADER *)response.buf)->ancount);
61			return 0;
62			}
63