]> git.meshlink.io Git - catta/blobdiff - avahi-core/dns.c
2008-06-24 Dimitris Glezos <dimitris@glezos.com> (via glezos@fedoraproject.org)
[catta] / avahi-core / dns.c
index 8c8b42bcbb56317ef0cefd4ee36bfd9f379afdab..41ccc8f3503c689e93ae6e612d22100f3656b3b5 100644 (file)
 #include <config.h>
 #endif
 
-#include <netinet/in.h>
-
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <assert.h>
 
+#include <sys/types.h>
+#include <netinet/in.h>
+
+#include <avahi-common/defs.h>
 #include <avahi-common/domain.h>
 #include <avahi-common/malloc.h>
 
@@ -56,6 +58,7 @@ 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;
@@ -150,6 +153,19 @@ void avahi_dns_packet_inc_field(AvahiDnsPacket *p, unsigned idx) {
     avahi_dns_packet_set_field(p, idx, avahi_dns_packet_get_field(p, idx) + 1);
 }   
 
+
+static void name_table_cleanup(void *key, void *value, void *user_data) {
+    AvahiDnsPacket *p = user_data;
+    
+    if ((uint8_t*) value >= AVAHI_DNS_PACKET_DATA(p) + p->size)
+        avahi_hashmap_remove(p->name_table, key);
+}
+
+void avahi_dns_packet_cleanup_name_table(AvahiDnsPacket *p) {
+    if (p->name_table)
+        avahi_hashmap_foreach(p->name_table, name_table_cleanup, p);
+}
+
 uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) {
     uint8_t *d, *saved_ptr = NULL;
     size_t saved_size;
@@ -213,6 +229,8 @@ uint8_t* avahi_dns_packet_append_name(AvahiDnsPacket *p, const char *name) {
 
 fail:
     p->size = saved_size;
+    avahi_dns_packet_cleanup_name_table(p);
+
     return NULL;
 }
 
@@ -320,7 +338,6 @@ int avahi_dns_packet_check_valid_multicast(AvahiDnsPacket *p) {
     return 0;
 }
 
-
 int avahi_dns_packet_is_query(AvahiDnsPacket *p) {
     assert(p);
     
@@ -331,9 +348,11 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_
     int ret = 0;
     int compressed = 0;
     int first_label = 1;
+    unsigned label_ptr;
+    int i;
     assert(p && ret_name && l);
     
-    for (;;) {
+    for (i = 0; i < AVAHI_DNS_LABELS_MAX; i++) {
         uint8_t n;
 
         if (idx+1 > p->size)
@@ -383,7 +402,12 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_
             if (idx+2 > p->size)
                 return -1;
 
-            idx = ((unsigned) (AVAHI_DNS_PACKET_DATA(p)[idx] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[idx+1];
+            label_ptr = ((unsigned) (AVAHI_DNS_PACKET_DATA(p)[idx] & ~0xC0)) << 8 | AVAHI_DNS_PACKET_DATA(p)[idx+1];
+
+            if ((label_ptr < AVAHI_DNS_PACKET_HEADER_SIZE) || (label_ptr >= idx))
+                return -1;
+
+            idx = label_ptr;
 
             if (!compressed)
                 ret += 2;
@@ -392,6 +416,8 @@ static int consume_labels(AvahiDnsPacket *p, unsigned idx, char *ret_name, size_
         } else
             return -1;
     }
+
+    return -1;
 }
 
 int avahi_dns_packet_consume_name(AvahiDnsPacket *p, char *ret_name, size_t l) {
@@ -495,88 +521,59 @@ 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_string_list_parse(avahi_dns_packet_get_rptr(p), rdlength, &r->data.txt.string_list) < 0)
+                    return -1;
                 
                 if (avahi_dns_packet_skip(p, rdlength) < 0)
-                    goto fail;
+                    return -1;
             } else
                 r->data.txt.string_list = NULL;
             
@@ -587,7 +584,7 @@ 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 +593,7 @@ 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;
             
@@ -607,20 +604,52 @@ AvahiRecord* avahi_dns_packet_consume_record(AvahiDnsPacket *p, int *ret_cache_f
             if (rdlength > 0) {
 
                 r->data.generic.data = avahi_memdup(avahi_dns_packet_get_rptr(p), rdlength);
+                r->data.generic.size = 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;
 
+    if (!avahi_record_is_valid(r))
+        goto fail;
+    
     return r;
 
 fail:
@@ -633,6 +662,7 @@ fail:
 AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_response) {
     char name[256];
     uint16_t type, class;
+    AvahiKey *k;
 
     assert(p);
 
@@ -646,7 +676,15 @@ AvahiKey* avahi_dns_packet_consume_key(AvahiDnsPacket *p, int *ret_unicast_respo
 
     class &= ~AVAHI_DNS_UNICAST_RESPONSE;
     
-    return avahi_key_new(name, class, type);
+    if (!(k = avahi_key_new(name, class, type)))
+        return NULL;
+
+    if (!avahi_key_is_valid(k)) {
+        avahi_key_unref(k);
+        return NULL;
+    }
+
+    return k;
 }
 
 uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast_response) {
@@ -662,30 +700,18 @@ uint8_t* avahi_dns_packet_append_key(AvahiDnsPacket *p, AvahiKey *k, int unicast
         !avahi_dns_packet_append_uint16(p, k->type) ||
         !avahi_dns_packet_append_uint16(p, k->clazz | (unicast_response ? AVAHI_DNS_UNICAST_RESPONSE : 0))) {
         p->size = size;
+        avahi_dns_packet_cleanup_name_table(p);
+
         return NULL;
     }
 
     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 +719,7 @@ 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 +729,14 @@ 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 +747,8 @@ 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;
@@ -734,31 +758,53 @@ 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);
+    assert(size <= AVAHI_DNS_RDATA_MAX);
 
 /*     avahi_log_debug("appended %u", size); */
 
@@ -770,6 +816,8 @@ uint8_t* avahi_dns_packet_append_record(AvahiDnsPacket *p, AvahiRecord *r, int c
 
 fail:
     p->size = size;
+    avahi_dns_packet_cleanup_name_table(p);
+
     return NULL;
 }
 
@@ -786,3 +834,46 @@ 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;
+}