Tighten DBC restrictions on message sections

dns_message_findname and dns_message_sectiontotext incorrectly accepted
DNS_SECTION_ANY.  If DNS_SECTION_ANY was passed the section array could
be incorrectly accessed at (-1).

dns_message_pseudosectiontotext and dns_message_pseudosectiontoyaml
incorrectly accepted DNS_PSEUDOSECTION_ANY.  These functions are
designed to process a single section.

diff --git a/lib/dns/include/dns/message.h b/lib/dns/include/dns/message.h
index a4246ee613ad8ccbf45473745d56938e54752b47..a6ec3b86da9d84037ab47a8416bf2e01522b4d4d 100644 (file)
--- a/lib/dns/include/dns/message.h
+++ b/lib/dns/include/dns/message.h
@@ -434,7 +434,7 @@ dns_message_pseudosectiontotext(dns_message_t *msg, dns_pseudosection_t section,
  *
  *\li  'target' is a valid buffer.
  *
- *\li  'section' is a valid section label.
+ *\li  'section' is a named section label.
  *
  * Ensures:
  *
@@ -806,7 +806,7 @@ dns_message_findname(dns_message_t *msg, dns_section_t section,
  * Requires:
  *\li  'msg' be valid.
  *
- *\li  'section' be a valid section.
+ *\li  'section' be a named section.
  *
  *\li  If a pointer to the name is desired, 'foundname' should be non-NULL.
  *     If it is non-NULL, '*foundname' MUST be NULL.

diff --git a/lib/dns/message.c b/lib/dns/message.c
index ccfd6b61e57d096a02a6cfb3b859d3c9db0eea9e..21ceaef0d361f302432d11231f9e187805969ae2 100644 (file)
--- a/lib/dns/message.c
+++ b/lib/dns/message.c
@@ -97,6 +97,8 @@ hexdump(const char *msg, const char *msg2, void *base, size_t len) {
                } else                                            \
                        isc_buffer_putstr(b, s);                  \
        }
+#define VALID_NAMED_PSEUDOSECTION(s) \
+       (((s) > DNS_PSEUDOSECTION_ANY) && ((s) < DNS_PSEUDOSECTION_MAX))
 #define VALID_PSEUDOSECTION(s) \
        (((s) >= DNS_PSEUDOSECTION_ANY) && ((s) < DNS_PSEUDOSECTION_MAX))
 
@@ -2452,7 +2454,7 @@ dns_message_findname(dns_message_t *msg, dns_section_t section,
         * to be filled in, that we can in fact fill it in.
         */
        REQUIRE(msg != NULL);
-       REQUIRE(VALID_SECTION(section));
+       REQUIRE(VALID_NAMED_SECTION(section));
        REQUIRE(target != NULL);
        REQUIRE(name == NULL || *name == NULL);
 
@@ -3302,7 +3304,7 @@ dns_message_sectiontotext(dns_message_t *msg, dns_section_t section,
 
        REQUIRE(DNS_MESSAGE_VALID(msg));
        REQUIRE(target != NULL);
-       REQUIRE(VALID_SECTION(section));
+       REQUIRE(VALID_NAMED_SECTION(section));
 
        saved_count = msg->indent.count;
 
@@ -3518,7 +3520,7 @@ dns_message_pseudosectiontoyaml(dns_message_t *msg, dns_pseudosection_t section,
 
        REQUIRE(DNS_MESSAGE_VALID(msg));
        REQUIRE(target != NULL);
-       REQUIRE(VALID_PSEUDOSECTION(section));
+       REQUIRE(VALID_NAMED_PSEUDOSECTION(section));
 
        saved_count = msg->indent.count;
 
@@ -3882,7 +3884,7 @@ dns_message_pseudosectiontotext(dns_message_t *msg, dns_pseudosection_t section,
 
        REQUIRE(DNS_MESSAGE_VALID(msg));
        REQUIRE(target != NULL);
-       REQUIRE(VALID_PSEUDOSECTION(section));
+       REQUIRE(VALID_NAMED_PSEUDOSECTION(section));
 
        if ((dns_master_styleflags(style) & DNS_STYLEFLAG_YAML) != 0) {
                return (dns_message_pseudosectiontoyaml(msg, section, style,