qmail/sme7/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	--- 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