* correctly handle empty domain names (i.e. the root zone)

* fix memory initialization error in wide-area.c
* make server_add_xx() functions atomic, i.e. clean up half-created entries on failure
* add some more validity checking macros and change everything to make use of them
* clean up avahi_server_add_address()
* change some functions from domain.[ch] to work on a stack buffer instead of malloced memory
* update avahi-test.c a little
* replace avahi_reverse_lookup_name_{ipv4,ipv6}() with a single function avahi_reverse_lookup_name()
* remove avahi_server_add_dns_server_name() from public API


git-svn-id: file:///home/lennart/svn/public/avahi/trunk@845 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

4 files changed, 70 insertions, 60 deletions

diff --git a/avahi-common/address.c b/avahi-common/address.c
index f3f3a67..d02d997 100644
--- a/avahi-common/address.c
+++ b/avahi-common/address.c
@@ -29,6 +29,7 @@
 #include <arpa/inet.h>
 #include <string.h>
 #include <assert.h>
+#include <stdio.h>
 
 #include "address.h"
 #include "malloc.h"
@@ -65,48 +66,42 @@ char *avahi_address_snprint(char *s, size_t length, const AvahiAddress *a) {
     return s;
 }
 
-char* avahi_reverse_lookup_name_ipv4(const AvahiIPv4Address *a) {
-    uint32_t n = ntohl(a->address);
+char* avahi_reverse_lookup_name(char *ret_s, size_t length, const AvahiAddress *a) {
+    assert(ret_s);
+    assert(length > 0);
     assert(a);
 
-    return avahi_strdup_printf("%u.%u.%u.%u.in-addr.arpa", n & 0xFF, (n >> 8) & 0xFF, (n >> 16) & 0xFF, n >> 24);
-}
+    if (a->proto == AVAHI_PROTO_INET) {
+        uint32_t n = ntohl(a->data.ipv4.address);
+        snprintf(
+            ret_s, length,
+            "%u.%u.%u.%u.in-addr.arpa",
+            n & 0xFF, (n >> 8) & 0xFF, (n >> 16) & 0xFF, n >> 24);
+    } else {
+        assert(a->proto == AVAHI_PROTO_INET6);
+
+        snprintf(
+            ret_s, length,
+            "%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.arpa",
+            a->data.ipv6.address[15] & 0xF, a->data.ipv6.address[15] >> 4,
+            a->data.ipv6.address[14] & 0xF, a->data.ipv6.address[14] >> 4,
+            a->data.ipv6.address[13] & 0xF, a->data.ipv6.address[13] >> 4,
+            a->data.ipv6.address[12] & 0xF, a->data.ipv6.address[12] >> 4,
+            a->data.ipv6.address[11] & 0xF, a->data.ipv6.address[11] >> 4,
+            a->data.ipv6.address[10] & 0xF, a->data.ipv6.address[10] >> 4,
+            a->data.ipv6.address[ 9] & 0xF, a->data.ipv6.address[ 9] >> 4,
+            a->data.ipv6.address[ 8] & 0xF, a->data.ipv6.address[ 8] >> 4,
+            a->data.ipv6.address[ 7] & 0xF, a->data.ipv6.address[ 7] >> 4,
+            a->data.ipv6.address[ 6] & 0xF, a->data.ipv6.address[ 6] >> 4,
+            a->data.ipv6.address[ 5] & 0xF, a->data.ipv6.address[ 5] >> 4,
+            a->data.ipv6.address[ 4] & 0xF, a->data.ipv6.address[ 4] >> 4,
+            a->data.ipv6.address[ 3] & 0xF, a->data.ipv6.address[ 3] >> 4,
+            a->data.ipv6.address[ 2] & 0xF, a->data.ipv6.address[ 2] >> 4,
+            a->data.ipv6.address[ 1] & 0xF, a->data.ipv6.address[ 1] >> 4,
+            a->data.ipv6.address[ 0] & 0xF, a->data.ipv6.address[ 0] >> 4);
+    }
 
-char *avahi_reverse_lookup_name_ipv6(const AvahiIPv6Address *a) {
-    
-    return avahi_strdup_printf("%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.%x.ip6.arpa",
-                           a->address[15] & 0xF,
-                           a->address[15] >> 4,
-                           a->address[14] & 0xF,
-                           a->address[14] >> 4,
-                           a->address[13] & 0xF,
-                           a->address[13] >> 4,
-                           a->address[12] & 0xF,
-                           a->address[12] >> 4,
-                           a->address[11] & 0xF,
-                           a->address[11] >> 4,
-                           a->address[10] & 0xF,
-                           a->address[10] >> 4,
-                           a->address[9] & 0xF,
-                           a->address[9] >> 4,
-                           a->address[8] & 0xF,
-                           a->address[8] >> 4,
-                           a->address[7] & 0xF,
-                           a->address[7] >> 4,
-                           a->address[6] & 0xF,
-                           a->address[6] >> 4,
-                           a->address[5] & 0xF,
-                           a->address[5] >> 4,
-                           a->address[4] & 0xF,
-                           a->address[4] >> 4,
-                           a->address[3] & 0xF,
-                           a->address[3] >> 4,
-                           a->address[2] & 0xF,
-                           a->address[2] >> 4,
-                           a->address[1] & 0xF,
-                           a->address[1] >> 4,
-                           a->address[0] & 0xF,
-                           a->address[0] >> 4);
+    return ret_s;
 }
 
 AvahiAddress *avahi_address_parse(const char *s, AvahiProtocol proto, AvahiAddress *ret_addr) {
diff --git a/avahi-common/address.h b/avahi-common/address.h
index f1ac428..c383250 100644
--- a/avahi-common/address.h
+++ b/avahi-common/address.h
@@ -102,11 +102,8 @@ AvahiAddress *avahi_address_from_sockaddr(const struct sockaddr* sa, AvahiAddres
 /** Return the port number of a sockaddr structure (either IPv4 or IPv6) */
 uint16_t avahi_port_from_sockaddr(const struct sockaddr* sa);
 
-/** Generate the DNS reverse lookup name for an IPv4 address. avahi_free() the result! */
-char* avahi_reverse_lookup_name_ipv4(const AvahiIPv4Address *a);
-
-/** Generate the modern DNS reverse lookup name for an IPv6 address, ending in ipv6.arpa. avahi_free() the result! */
-char* avahi_reverse_lookup_name_ipv6(const AvahiIPv6Address *a);
+/** Generate the DNS reverse lookup name for an IPv4 or IPv6 address. */
+char* avahi_reverse_lookup_name(char *ret_s, size_t length, const AvahiAddress *a);
 
 /** Check whether the specified IPv6 address is in fact an
  * encapsulated IPv4 address, returns 1 if yes, 0 otherwise */
diff --git a/avahi-common/domain-test.c b/avahi-common/domain-test.c
index f1313cb..279be72 100644
--- a/avahi-common/domain-test.c
+++ b/avahi-common/domain-test.c
@@ -110,5 +110,12 @@ int main(int argc, char *argv[]) {
     assert(avahi_is_valid_host_name("sfooo."));
     assert(avahi_is_valid_host_name("sfooo"));
 
+    assert(avahi_is_valid_domain_name("."));
+    assert(avahi_is_valid_domain_name(""));
+
+    assert(avahi_normalize_name(".", t, sizeof(t)));
+    assert(avahi_normalize_name("", t, sizeof(t)));
+
+    
     return 0;
 }
diff --git a/avahi-common/domain.c b/avahi-common/domain.c
index 988ba7e..7d954de 100644
--- a/avahi-common/domain.c
+++ b/avahi-common/domain.c
@@ -206,31 +206,35 @@ char *avahi_normalize_name(const char *s, char *ret_s, size_t size) {
     assert(size > 0);
 
     r = ret_s;
+    *ret_s = 0;
+
     while (*s) {
         char label[AVAHI_LABEL_MAX];
 
         if (!(avahi_unescape_label(&s, label, sizeof(label))))
             return NULL;
 
-        if (strlen(label) > 0) {
-
-            if (!empty) {
-                if (size < 1)
-                    return NULL;
+        if (label[0] == 0) {
 
-                *(r++) = '.';
-                size--;
+            if (*s == 0 && empty)
+                return ret_s;
 
-            } else
-                empty = 0;
-            
-            avahi_escape_label(label, strlen(label), &r, &size);
+            return NULL;
         }
+        
+        if (!empty) {
+            if (size < 1)
+                return NULL;
+            
+            *(r++) = '.';
+            size--;
+            
+        } else
+            empty = 0;
+            
+        avahi_escape_label(label, strlen(label), &r, &size);
     }
 
-    if (empty)
-        return NULL;
-    
     return ret_s;
 }
 
@@ -409,9 +413,10 @@ int avahi_is_valid_service_subtype(const char *t) {
 }
 
 int avahi_is_valid_domain_name(const char *t) {
+    int is_first = 1;
     assert(t);
 
-    if (strlen(t) >= AVAHI_DOMAIN_NAME_MAX || !*t)
+    if (strlen(t) >= AVAHI_DOMAIN_NAME_MAX)
         return 0;
 
     do {
@@ -420,7 +425,13 @@ int avahi_is_valid_domain_name(const char *t) {
         if (!(avahi_unescape_label(&t, label, sizeof(label))))
             return 0;
 
-        if (strlen(label) < 1)
+        /* Explicitly allow the root domain name */
+        if (is_first && label[0] == 0 && *t == 0)
+            return 1;
+        
+        is_first = 0;
+        
+        if (label[0] == 0)
             return 0;
         
     } while (*t);