* add new core API functions avahi_rdata_serialize() and avahi_rdata_parse()

* add new definition AVAHI_DNS_RDATA_MAX
* update dns-test.c and add examples for avahi_rdata_{serialize,parse}()


git-svn-id: file:///home/lennart/svn/public/avahi/trunk@867 941a03a8-eaeb-0310-b9a0-b1bbd8fe43fe

4 files changed, 177 insertions, 86 deletions

diff --git a/avahi-core/dns-test.c b/avahi-core/dns-test.c
index e5369a9..2336f42 100644
--- a/avahi-core/dns-test.c
+++ b/avahi-core/dns-test.c
@@ -24,43 +24,77 @@
 #endif
 
 #include <assert.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
 
 #include <avahi-common/domain.h>
+#include <avahi-common/malloc.h>
 
 #include "dns.h"
 #include "log.h"
 #include "util.h"
 
 int main(int argc, char *argv[]) {
-    char t[256];
+    char t[AVAHI_DOMAIN_NAME_MAX];
     const char *a, *b, *c, *d;
     AvahiDnsPacket *p;
+    AvahiRecord *r, *r2;
+    uint8_t rdata[AVAHI_DNS_RDATA_MAX];
+    size_t l;
 
     p = avahi_dns_packet_new(0);
 
-    avahi_dns_packet_append_name(p, a = "hello.hello.hello.de.");
-    avahi_dns_packet_append_name(p, b = "this is a test.hello.de."); 
-    avahi_dns_packet_append_name(p, c = "this\\.is\\.a\\.test\\.with\\.dots.hello.de."); 
-    avahi_dns_packet_append_name(p, d = "this\\\\is another\\ \\test.hello.de."); 
+    assert(avahi_dns_packet_append_name(p, a = "Ahello.hello.hello.de."));
+    assert(avahi_dns_packet_append_name(p, b = "Bthis is a test.hello.de."));
+    assert(avahi_dns_packet_append_name(p, c = "Cthis\\.is\\.a\\.test\\.with\\.dots.hello.de."));
+    assert(avahi_dns_packet_append_name(p, d = "Dthis\\\\is another test.hello.de."));
 
     avahi_hexdump(AVAHI_DNS_PACKET_DATA(p), p->size);
 
-    avahi_dns_packet_consume_name(p, t, sizeof(t));
+    assert(avahi_dns_packet_consume_name(p, t, sizeof(t)) == 0);
     avahi_log_debug(">%s<", t);
     assert(avahi_domain_equal(a, t));
     
-    avahi_dns_packet_consume_name(p, t, sizeof(t));
+    assert(avahi_dns_packet_consume_name(p, t, sizeof(t)) == 0);
     avahi_log_debug(">%s<", t);
     assert(avahi_domain_equal(b, t));
 
-    avahi_dns_packet_consume_name(p, t, sizeof(t));
+    assert(avahi_dns_packet_consume_name(p, t, sizeof(t)) == 0);
     avahi_log_debug(">%s<", t);
     assert(avahi_domain_equal(c, t));
 
-    avahi_dns_packet_consume_name(p, t, sizeof(t));
+    assert(avahi_dns_packet_consume_name(p, t, sizeof(t)) == 0);
     avahi_log_debug(">%s<", t);
     assert(avahi_domain_equal(d, t));
     
     avahi_dns_packet_free(p);
+
+    /* RDATA PARSING AND SERIALIZATION */
+    
+    /* Create an AvahiRecord with some usful data */
+    r = avahi_record_new_full("foobar.local", AVAHI_DNS_CLASS_IN, AVAHI_DNS_TYPE_HINFO, AVAHI_DEFAULT_TTL);
+    assert(r);
+    r->data.hinfo.cpu = avahi_strdup("FOO");
+    r->data.hinfo.os = avahi_strdup("BAR");
+
+    /* Serialize it into a blob */
+    assert((l = avahi_rdata_serialize(r, rdata, sizeof(rdata))) != (size_t) -1);
+
+    /* Print it */
+    avahi_hexdump(rdata, l);
+
+    /* Create a new record and fill in the data from the blob */
+    r2 = avahi_record_new(r->key, AVAHI_DEFAULT_TTL);
+    assert(r2);
+    assert(avahi_rdata_parse(r2, rdata, l) >= 0);
+
+    /* Compare both versions */
+    assert(avahi_record_equal_no_ttl(r, r2));
+
+    /* Free the records */
+    avahi_record_unref(r);
+    avahi_record_unref(r2);
+    
     return 0;
 }
diff --git a/avahi-core/dns.c b/avahi-core/dns.c
index 8c8b42b..63ea8a0 100644
--- a/avahi-core/dns.c
+++ b/avahi-core/dns.c
@@ -56,6 +56,7 @@ AvahiDnsPacket* avahi_dns_packet_new(unsigned mtu) {
     p->size = p->rindex = AVAHI_DNS_PACKET_HEADER_SIZE;
     p->max_size = max_size;
     p->name_table = NULL;
+    p->data = NULL;
 
     memset(AVAHI_DNS_PACKET_DATA(p), 0, p->size);
     return p;
@@ -495,88 +496,58 @@ int avahi_dns_packet_skip(AvahiDnsPacket *p, size_t length) {
     return 0;
 }
 
-AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_flush) {
-    char name[257], buf[257];
-    uint16_t type, class;
-    uint32_t ttl;
-    uint16_t rdlength;
-    AvahiRecord *r = NULL;
+static int parse_rdata(AvahiDnsPacket *p, AvahiRecord *r, uint16_t rdlength) {
+    char buf[AVAHI_DOMAIN_NAME_MAX];
     const void* start;
-
+    
     assert(p);
+    assert(r);
 
-/*     avahi_log_debug("consume_record()"); */
-
-    if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 ||
-        avahi_dns_packet_consume_uint16(p, &type) < 0 ||
-        avahi_dns_packet_consume_uint16(p, &class) < 0 ||
-        avahi_dns_packet_consume_uint32(p, &ttl) < 0 ||
-        avahi_dns_packet_consume_uint16(p, &rdlength) < 0 ||
-        p->rindex + rdlength > p->size)
-        goto fail;
-
-/*     avahi_log_debug("name = %s, rdlength = %u", name, rdlength); */
-
-    if (ret_cache_flush)
-        *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH);
-    class &= ~AVAHI_DNS_CACHE_FLUSH;
-    
     start = avahi_dns_packet_get_rptr(p);
-    
-    if (!(r = avahi_record_new_full(name, class, type, ttl)))
-        return NULL;
-    
-    switch (type) {
+ 
+    switch (r->key->type) {
         case AVAHI_DNS_TYPE_PTR:
         case AVAHI_DNS_TYPE_CNAME:
         case AVAHI_DNS_TYPE_NS:
-
-/*             avahi_log_debug("ptr"); */
             
             if (avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0)
-                goto fail;
+                return -1;
 
             r->data.ptr.name = avahi_strdup(buf);
             break;
 
             
         case AVAHI_DNS_TYPE_SRV:
-
-/*             avahi_log_debug("srv"); */
             
             if (avahi_dns_packet_consume_uint16(p, &r->data.srv.priority) < 0 ||
                 avahi_dns_packet_consume_uint16(p, &r->data.srv.weight) < 0 ||
                 avahi_dns_packet_consume_uint16(p, &r->data.srv.port) < 0 ||
                 avahi_dns_packet_consume_name(p, buf, sizeof(buf)) < 0)
-                goto fail;
+                return -1;
             
             r->data.srv.name = avahi_strdup(buf);
             break;
 
         case AVAHI_DNS_TYPE_HINFO:
-            
-/*             avahi_log_debug("hinfo"); */
 
             if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0)
-                goto fail;
-
+                return -1;
+            
             r->data.hinfo.cpu = avahi_strdup(buf);
-
+            
             if (avahi_dns_packet_consume_string(p, buf, sizeof(buf)) < 0)
-                goto fail;
-
+                return -1;
+            
             r->data.hinfo.os = avahi_strdup(buf);
             break;
 
         case AVAHI_DNS_TYPE_TXT:
 
-/*             avahi_log_debug("txt"); */
-
             if (rdlength > 0) {
                 r->data.txt.string_list = avahi_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength);
                 
                 if (avahi_dns_packet_skip(p, rdlength) < 0)
-                    goto fail;
+                    return -1;
             } else
                 r->data.txt.string_list = NULL;
             
@@ -587,7 +558,7 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f
 /*             avahi_log_debug("A"); */
 
             if (avahi_dns_packet_consume_bytes(p, &r->data.a.address, sizeof(AvahiIPv4Address)) < 0)
-                goto fail;
+                return -1;
             
             break;
 
@@ -596,7 +567,7 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f
 /*             avahi_log_debug("aaaa"); */
             
             if (avahi_dns_packet_consume_bytes(p, &r->data.aaaa.address, sizeof(AvahiIPv6Address)) < 0)
-                goto fail;
+                return -1;
             
             break;
             
@@ -609,18 +580,46 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f
                 r->data.generic.data = avahi_memdup(avahi_dns_packet_get_rptr(p), rdlength);
                 
                 if (avahi_dns_packet_skip(p, rdlength) < 0)
-                    goto fail;
+                    return -1;
             }
 
             break;
     }
 
-/*     avahi_log_debug("%i == %u ?", (uint8_t*) avahi_dns_packet_get_rptr(p) - (uint8_t*) start, rdlength); */
-    
     /* Check if we read enough data */
     if ((const uint8_t*) avahi_dns_packet_get_rptr(p) - (const uint8_t*) start != rdlength)
+        return -1;
+    
+    return 0;
+}
+
+AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_flush) {
+    char name[AVAHI_DOMAIN_NAME_MAX];
+    uint16_t type, class;
+    uint32_t ttl;
+    uint16_t rdlength;
+    AvahiRecord *r = NULL;
+
+    assert(p);
+
+    if (avahi_dns_packet_consume_name(p, name, sizeof(name)) < 0 ||
+        avahi_dns_packet_consume_uint16(p, &type) < 0 ||
+        avahi_dns_packet_consume_uint16(p, &class) < 0 ||
+        avahi_dns_packet_consume_uint32(p, &ttl) < 0 ||
+        avahi_dns_packet_consume_uint16(p, &rdlength) < 0 ||
+        p->rindex + rdlength > p->size)
         goto fail;
 
+    if (ret_cache_flush)
+        *ret_cache_flush = !!(class & AVAHI_DNS_CACHE_FLUSH);
+    class &= ~AVAHI_DNS_CACHE_FLUSH;
+    
+    if (!(r = avahi_record_new_full(name, class, type, ttl)))
+        goto fail;
+    
+    if (parse_rdata(p, r, rdlength) < 0)
+        goto fail;
+    
     return r;
 
 fail:
@@ -668,24 +667,10 @@ uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast
     return t;
 }
 
-uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int cache_flush, unsigned max_ttl) {
-    uint8_t *t, *l, *start;
-    size_t size;
-
+static int append_rdata(AvahiDnsPacket *p, AvahiRecord *r) {
     assert(p);
     assert(r);
-
-    size = p->size;
-
-    if (!(t = avahi_dns_packet_append_name(p, r->key->name)) ||
-        !avahi_dns_packet_append_uint16(p, r->key->type) ||
-        !avahi_dns_packet_append_uint16(p, cache_flush ? (r->key->clazz | AVAHI_DNS_CACHE_FLUSH) : (r->key->clazz &~ AVAHI_DNS_CACHE_FLUSH)) ||
-        !avahi_dns_packet_append_uint32(p, (max_ttl && r->ttl > max_ttl) ? max_ttl : r->ttl) ||
-        !(l = avahi_dns_packet_append_uint16(p, 0)))
-        goto fail;
-
-    start = avahi_dns_packet_extend(p, 0);
-
+    
     switch (r->key->type) {
         
         case AVAHI_DNS_TYPE_PTR:
@@ -693,7 +678,7 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c
         case AVAHI_DNS_TYPE_NS:
             
             if (!(avahi_dns_packet_append_name(p, r->data.ptr.name)))
-                goto fail;
+                return -1;
             
             break;
 
@@ -703,14 +688,14 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c
                 !avahi_dns_packet_append_uint16(p, r->data.srv.weight) ||
                 !avahi_dns_packet_append_uint16(p, r->data.srv.port) ||
                 !avahi_dns_packet_append_name(p, r->data.srv.name))
-                goto fail;
+                return -1;
 
             break;
 
         case AVAHI_DNS_TYPE_HINFO:
             if (!avahi_dns_packet_append_string(p, r->data.hinfo.cpu) ||
                 !avahi_dns_packet_append_string(p, r->data.hinfo.os))
-                goto fail;
+                return -1;
 
             break;
 
@@ -721,10 +706,8 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c
 
             n = avahi_string_list_serialize(r->data.txt.string_list, NULL, 0);
 
-/*             avahi_log_debug("appending string: %u %p", n, r->data.txt.string_list); */
-
             if (!(data = avahi_dns_packet_extend(p, n)))
-                goto fail;
+                return -1;
 
             avahi_string_list_serialize(r->data.txt.string_list, data, n);
             break;
@@ -734,28 +717,50 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c
         case AVAHI_DNS_TYPE_A:
 
             if (!avahi_dns_packet_append_bytes(p, &r->data.a.address, sizeof(r->data.a.address)))
-                goto fail;
+                return -1;
             
             break;
 
         case AVAHI_DNS_TYPE_AAAA:
             
             if (!avahi_dns_packet_append_bytes(p, &r->data.aaaa.address, sizeof(r->data.aaaa.address)))
-                goto fail;
+                return -1;
             
             break;
             
         default:
 
-            if (r->data.generic.size &&
-                avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size))
-                goto fail;
+            if (r->data.generic.size)
+                if (avahi_dns_packet_append_bytes(p, r->data.generic.data, r->data.generic.size))
+                    return -1;
 
             break;
     }
 
+    return 0;
+}
+
 
+uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int cache_flush, unsigned max_ttl) {
+    uint8_t *t, *l, *start;
+    size_t size;
+
+    assert(p);
+    assert(r);
+
+    size = p->size;
+
+    if (!(t = avahi_dns_packet_append_name(p, r->key->name)) ||
+        !avahi_dns_packet_append_uint16(p, r->key->type) ||
+        !avahi_dns_packet_append_uint16(p, cache_flush ? (r->key->clazz | AVAHI_DNS_CACHE_FLUSH) : (r->key->clazz &~ AVAHI_DNS_CACHE_FLUSH)) ||
+        !avahi_dns_packet_append_uint32(p, (max_ttl && r->ttl > max_ttl) ? max_ttl : r->ttl) ||
+        !(l = avahi_dns_packet_append_uint16(p, 0)))
+        goto fail;
+
+    start = avahi_dns_packet_extend(p, 0);
 
+    if (append_rdata(p, r) < 0)
+        goto fail;
     
     size = avahi_dns_packet_extend(p, 0) - start;
     assert(size <= 0xFFFF);
@@ -786,3 +791,46 @@ size_t avahi_dns_packet_space(AvahiDnsPacket *p) {
     
     return p->max_size - p->size;
 }
+
+int avahi_rdata_parse(AvahiRecord *record, const void* rdata, size_t size) {
+    int ret;
+    AvahiDnsPacket p;
+    
+    assert(record);
+    assert(rdata);
+    
+    p.data = (void*) rdata;
+    p.max_size = p.size = size;
+    p.rindex = 0;
+    p.name_table = NULL;
+
+    ret = parse_rdata(&p, record, size);
+
+    assert(!p.name_table);
+    
+    return ret;
+}
+
+size_t avahi_rdata_serialize(AvahiRecord *record, void *rdata, size_t max_size) {
+    int ret;
+    AvahiDnsPacket p;
+    
+    assert(record);
+    assert(rdata);
+    assert(max_size > 0);
+
+    p.data = (void*) rdata;
+    p.max_size = max_size;
+    p.size = p.rindex = 0;
+    p.name_table = NULL;
+
+    ret = append_rdata(&p, record);
+
+    if (p.name_table)
+         avahi_hashmap_free(p.name_table);
+
+    if (ret < 0)
+        return (size_t) -1;
+    
+    return p.size;
+}
diff --git a/avahi-core/dns.h b/avahi-core/dns.h
index 61ec189..4696e00 100644
--- a/avahi-core/dns.h
+++ b/avahi-core/dns.h
@@ -32,9 +32,10 @@
 typedef struct AvahiDnsPacket {
     size_t size, rindex, max_size;
     AvahiHashmap *name_table; /* for name compression */
+    uint8_t *data;
 } AvahiDnsPacket;
 
-#define AVAHI_DNS_PACKET_DATA(p) (((uint8_t*) p) + sizeof(AvahiDnsPacket))
+#define AVAHI_DNS_PACKET_DATA(p) ((p)->data ? (p)->data : ((uint8_t*) p) + sizeof(AvahiDnsPacket))
 
 AvahiDnsPacket* avahi_dns_packet_new(unsigned mtu);
 AvahiDnsPacket* avahi_dns_packet_new_query(unsigned mtu);
@@ -104,5 +105,7 @@ size_t avahi_dns_packet_space(AvahiDnsPacket *p);
 #define AVAHI_MDNS_SUFFIX_ADDR_IPV4 "254.169.in-addr.arpa"
 #define AVAHI_MDNS_SUFFIX_ADDR_IPV6 "0.8.e.f.ip6.arpa"
 
+#define AVAHI_DNS_RDATA_MAX 65535
+
 #endif
 
diff --git a/avahi-core/rr.h b/avahi-core/rr.h
index 7c00152..63dc18d 100644
--- a/avahi-core/rr.h
+++ b/avahi-core/rr.h
@@ -208,6 +208,12 @@ int avahi_key_is_valid(AvahiKey *k);
 /** Check whether the specified record is valid */
 int avahi_record_is_valid(AvahiRecord *r);
 
+/** Parse a binary rdata object and fill it into *record. This function is actually implemented in dns.c */
+int avahi_rdata_parse(AvahiRecord *record, const void* rdata, size_t size);
+
+/** Serialize an AvahiRecord object into binary rdata. This function is actually implemented in dns.c */
+size_t avahi_rdata_serialize(AvahiRecord *record, void *rdata, size_t max_size);
+
 AVAHI_C_DECL_END
 
 #endif