#include "dns.h"
-flxDnsPacket* flx_dns_packet_new(void) {
+flxDnsPacket* flx_dns_packet_new(guint max_size) {
flxDnsPacket *p;
- p = g_new(flxDnsPacket, 1);
- p->size = p->rindex = 2*6;
- memset(p->data, 0, p->size);
+
+ if (max_size <= 0)
+ max_size = FLX_DNS_PACKET_MAX_SIZE;
+ else if (max_size < FLX_DNS_PACKET_HEADER_SIZE)
+ max_size = FLX_DNS_PACKET_HEADER_SIZE;
+
+ p = g_malloc(sizeof(flxDnsPacket) + max_size);
+ p->size = p->rindex = FLX_DNS_PACKET_HEADER_SIZE;
+ p->max_size = max_size;
+
+ memset(FLX_DNS_PACKET_DATA(p), 0, p->size);
+ return p;
+}
+
+flxDnsPacket* flx_dns_packet_new_query(guint max_size) {
+ flxDnsPacket *p;
+
+ p = flx_dns_packet_new(max_size);
+ flx_dns_packet_set_field(p, DNS_FIELD_FLAGS, DNS_FLAGS(0, 0, 0, 0, 0, 0, 0, 0, 0, 0));
+ return p;
+}
+
+flxDnsPacket* flx_dns_packet_new_response(guint max_size) {
+ flxDnsPacket *p;
+
+ p = flx_dns_packet_new(max_size);
+ flx_dns_packet_set_field(p, DNS_FIELD_FLAGS, DNS_FLAGS(1, 0, 0, 0, 0, 0, 0, 0, 0, 0));
return p;
}
void flx_dns_packet_set_field(flxDnsPacket *p, guint index, guint16 v) {
g_assert(p);
- g_assert(index < 2*6);
+ g_assert(index < FLX_DNS_PACKET_HEADER_SIZE);
- ((guint16*) p->data)[index] = g_htons(v);
+ ((guint16*) FLX_DNS_PACKET_DATA(p))[index] = g_htons(v);
}
guint16 flx_dns_packet_get_field(flxDnsPacket *p, guint index) {
g_assert(p);
- g_assert(index < 2*6);
+ g_assert(index < FLX_DNS_PACKET_HEADER_SIZE);
- return g_ntohs(((guint16*) p->data)[index]);
+ return g_ntohs(((guint16*) FLX_DNS_PACKET_DATA(p))[index]);
}
guint8* flx_dns_packet_append_name(flxDnsPacket *p, const gchar *name) {
guint8 *d, *f = NULL;
+ guint saved_size;
g_assert(p);
g_assert(name);
+ saved_size = p->size;
+
for (;;) {
guint n = strcspn(name, ".");
if (!n || n > 63)
- return NULL;
+ goto fail;
- d = flx_dns_packet_extend(p, n+1);
+ if (!(d = flx_dns_packet_extend(p, n+1)))
+ goto fail;
+
if (!f)
f = d;
d[0] = n;
break;
}
- d = flx_dns_packet_extend(p, 1);
+ if (!(d = flx_dns_packet_extend(p, 1)))
+ goto fail;
+
d[0] = 0;
return f;
+
+fail:
+ p->size = saved_size;
+ return NULL;
}
guint8* flx_dns_packet_append_uint16(flxDnsPacket *p, guint16 v) {
guint8 *d;
-
g_assert(p);
- d = flx_dns_packet_extend(p, sizeof(guint16));
- *((guint16*) d) = g_htons(v);
+ if (!(d = flx_dns_packet_extend(p, sizeof(guint16))))
+ return NULL;
+ *((guint16*) d) = g_htons(v);
return d;
}
guint8 *flx_dns_packet_append_uint32(flxDnsPacket *p, guint32 v) {
guint8 *d;
-
g_assert(p);
- d = flx_dns_packet_extend(p, sizeof(guint32));
+
+ if (!(d = flx_dns_packet_extend(p, sizeof(guint32))))
+ return NULL;
+
*((guint32*) d) = g_htonl(v);
return d;
g_assert(b);
g_assert(l);
- d = flx_dns_packet_extend(p, l);
- g_assert(d);
- memcpy(d, b, l);
+ if (!(d = flx_dns_packet_extend(p, l)))
+ return NULL;
+ memcpy(d, b, l);
return d;
}
-
guint8 *flx_dns_packet_extend(flxDnsPacket *p, guint l) {
guint8 *d;
g_assert(p);
- g_assert(p->size+l <= sizeof(p->data));
- d = p->data + p->size;
+ if (p->size+l > p->max_size)
+ return NULL;
+
+ d = FLX_DNS_PACKET_DATA(p) + p->size;
p->size += l;
return d;
if (!prev)
return flx_dns_packet_append_name(p, name);
- k = prev - p->data;
+ k = prev - FLX_DNS_PACKET_DATA(p);
if (k < 0 || k >= 0x4000 || (guint) k >= p->size)
return flx_dns_packet_append_name(p, name);
- d = (guint16*) flx_dns_packet_extend(p, sizeof(guint16));
- *d = g_htons((0xC000 | k));
+ if (!(d = (guint16*) flx_dns_packet_extend(p, sizeof(guint16))))
+ return NULL;
+ *d = g_htons((0xC000 | k));
return prev;
}
if (index+1 > p->size)
return -1;
- n = p->data[index];
+ n = FLX_DNS_PACKET_DATA(p)[index];
if (!n) {
index++;
} else
first_label = 0;
- memcpy(ret_name, p->data + index, n);
+ memcpy(ret_name, FLX_DNS_PACKET_DATA(p) + index, n);
index += n;
ret_name += n;
l -= n;
if (index+2 > p->size)
return -1;
- index = ((guint) (p->data[index] & ~0xC0)) << 8 | p->data[index+1];
+ index = ((guint) (FLX_DNS_PACKET_DATA(p)[index] & ~0xC0)) << 8 | FLX_DNS_PACKET_DATA(p)[index+1];
if (!compressed)
ret += 2;
if (p->rindex + sizeof(guint16) > p->size)
return -1;
- *ret_v = g_ntohs(*((guint16*) (p->data + p->rindex)));
+ *ret_v = g_ntohs(*((guint16*) (FLX_DNS_PACKET_DATA(p) + p->rindex)));
p->rindex += sizeof(guint16);
return 0;
if (p->rindex + sizeof(guint32) > p->size)
return -1;
- *ret_v = g_ntohl(*((guint32*) (p->data + p->rindex)));
+ *ret_v = g_ntohl(*((guint32*) (FLX_DNS_PACKET_DATA(p) + p->rindex)));
p->rindex += sizeof(guint32);
return 0;
if (p->rindex + l > p->size)
return -1;
- memcpy(ret_data, p->data + p->rindex, l);
+ memcpy(ret_data, FLX_DNS_PACKET_DATA(p) + p->rindex, l);
p->rindex += l;
return 0;
if (p->rindex >= p->size)
return NULL;
- return p->data + p->rindex;
+ return FLX_DNS_PACKET_DATA(p) + p->rindex;
}
gint flx_dns_packet_skip(flxDnsPacket *p, guint length) {