djbdns/sme9/240-tinydns-alias-chain-truncation.patch

--- a/tdlookup.c
+++ b/tdlookup.c
@@ -103,12 +103,13 @@ static int doname(void)
   return response_addname(d1);
 }
 
-static int doit(char *q,char qtype[2])
+static int doit1(char **pqname,char qtype[2])
 {
   unsigned int bpos;
   unsigned int anpos;
   unsigned int aupos;
   unsigned int arpos;
+  char *q;
   char *control;
   char *wild;
   int flaggavesoa;
@@ -122,6 +123,12 @@ static int doit(char *q,char qtype[2])
   int addrnum;
   uint32 addrttl;
   int i;
+  int loop = 0 ;
+
+RESTART:
+  if (loop++ >= 100) return 0 ;
+
+  q = *pqname ;
 
   anpos = response_len;
 
@@ -136,7 +143,14 @@ static int doit(char *q,char qtype[2])
       if (byte_equal(type,2,DNS_T_NS)) flagns = 1;
     }
     if (flagns) break;
-    if (!*control) return 0; /* q is not within our bailiwick */
+    if (!*control) { /* q is not within our bailiwick */
+      if (loop <= 1)
+        return 0 ;
+      else {
+        response[2] &= ~4;
+        goto DONE; /* The administrator has issued contradictory instructions */
+      }
+    }
     control += *control;
     control += 1;
   }
@@ -172,9 +186,17 @@ static int doit(char *q,char qtype[2])
        continue;
       }
       if (!response_rstart(q,type,ttl)) return 0;
-      if (byte_equal(type,2,DNS_T_NS) || byte_equal(type,2,DNS_T_CNAME) || byte_equal(type,2,DNS_T_PTR)) {
+      if (byte_equal(type,2,DNS_T_NS) || byte_equal(type,2,DNS_T_PTR)) {
        if (!doname()) return 0;
       }
+      else if (byte_equal(type,2,DNS_T_CNAME)) {
+       if (!doname()) return 0;
+        if (byte_diff(type,2,qtype)) {
+         response_rfinish(RESPONSE_ANSWER);
+         if (!dns_domain_copy(pqname,d1)) return 0 ;
+         goto RESTART ;
+       }
+      }
       else if (byte_equal(type,2,DNS_T_MX)) {
        if (!dobytes(2)) return 0;
        if (!doname()) return 0;
@@ -275,9 +297,21 @@ static int doit(char *q,char qtype[2])
     }
   }
 
+DONE:
   return 1;
 }
 
+static int doit(char *qname,char qtype[2])
+{
+  int r ;
+  char * q = 0 ;
+
+  if (!dns_domain_copy(&q, qname)) return 0 ;
+  r = doit1(&q, qtype) ;
+  dns_domain_free(&q) ;
+  return r ;
+}
+
 int respond(char *q,char qtype[2],char ip[4])
 {
   static struct tai cdb_valid = { 0 };
1	--- a/tdlookup.c
2	+++ b/tdlookup.c
3	@@ -103,12 +103,13 @@ static int doname(void)
4	return response_addname(d1);
5	}
6
7	-static int doit(char *q,char qtype[2])
8	+static int doit1(char **pqname,char qtype[2])
9	{
10	unsigned int bpos;
11	unsigned int anpos;
12	unsigned int aupos;
13	unsigned int arpos;
14	+ char *q;
15	char *control;
16	char *wild;
17	int flaggavesoa;
18	@@ -122,6 +123,12 @@ static int doit(char *q,char qtype[2])
19	int addrnum;
20	uint32 addrttl;
21	int i;
22	+ int loop = 0 ;
23	+
24	+RESTART:
25	+ if (loop++ >= 100) return 0 ;
26	+
27	+ q = *pqname ;
28
29	anpos = response_len;
30
31	@@ -136,7 +143,14 @@ static int doit(char *q,char qtype[2])
32	if (byte_equal(type,2,DNS_T_NS)) flagns = 1;
33	}
34	if (flagns) break;
35	- if (!control) return 0; / q is not within our bailiwick */
36	+ if (!control) { / q is not within our bailiwick */
37	+ if (loop <= 1)
38	+ return 0 ;
39	+ else {
40	+ response[2] &= ~4;
41	+ goto DONE; /* The administrator has issued contradictory instructions */
42	+ }
43	+ }
44	control += *control;
45	control += 1;
46	}
47	@@ -172,9 +186,17 @@ static int doit(char *q,char qtype[2])
48	continue;
49	}
50	if (!response_rstart(q,type,ttl)) return 0;
51	- if (byte_equal(type,2,DNS_T_NS) \|\| byte_equal(type,2,DNS_T_CNAME) \|\| byte_equal(type,2,DNS_T_PTR)) {
52	+ if (byte_equal(type,2,DNS_T_NS) \|\| byte_equal(type,2,DNS_T_PTR)) {
53	if (!doname()) return 0;
54	}
55	+ else if (byte_equal(type,2,DNS_T_CNAME)) {
56	+ if (!doname()) return 0;
57	+ if (byte_diff(type,2,qtype)) {
58	+ response_rfinish(RESPONSE_ANSWER);
59	+ if (!dns_domain_copy(pqname,d1)) return 0 ;
60	+ goto RESTART ;
61	+ }
62	+ }
63	else if (byte_equal(type,2,DNS_T_MX)) {
64	if (!dobytes(2)) return 0;
65	if (!doname()) return 0;
66	@@ -275,9 +297,21 @@ static int doit(char *q,char qtype[2])
67	}
68	}
69
70	+DONE:
71	return 1;
72	}
73
74	+static int doit(char *qname,char qtype[2])
75	+{
76	+ int r ;
77	+ char * q = 0 ;
78	+
79	+ if (!dns_domain_copy(&q, qname)) return 0 ;
80	+ r = doit1(&q, qtype) ;
81	+ dns_domain_free(&q) ;
82	+ return r ;
83	+}
84	+
85	int respond(char *q,char qtype[2],char ip[4])
86	{
87	static struct tai cdb_valid = { 0 };