#include "announce.h"
#include "util.h"
#include "dns.h"
+#include "cache.h"
+#include "service.h"
#include "interface.h"
-char rdata_buffer[MAX_DATA_LEN + 1];
static char name_buffer[MAX_NAME_LEN + 1];
const char*
}
void
-dns_send_answer(struct uloop_fd *u, const char *answer)
+dns_send_answer(struct interface *iface, const char *answer)
{
uint8_t buffer[256];
struct dns_header h = { 0 };
DBG(1, "A <- %s %s\n", dns_type_string(dns_reply[i].type), answer);
}
- if (interface_send_packet(cur_iface, iov, (dns_answer_cnt * 3) + 1) < 0)
+ if (interface_send_packet(iface, iov, (dns_answer_cnt * 3) + 1) < 0)
fprintf(stderr, "failed to send question\n");
for (i = 0; i < dns_answer_cnt; i++) {
return offset + 1;
}
-struct dns_header*
+static struct dns_header*
dns_consume_header(uint8_t **data, int *len)
{
struct dns_header *h = (struct dns_header *) *data;
return h;
}
-struct dns_question*
+static struct dns_question*
dns_consume_question(uint8_t **data, int *len)
{
struct dns_question *q = (struct dns_question *) *data;
return q;
}
-struct dns_answer*
+static struct dns_answer*
dns_consume_answer(uint8_t **data, int *len)
{
struct dns_answer *a = (struct dns_answer *) *data;
return a;
}
-char*
+static char *
dns_consume_name(const uint8_t *base, int blen, uint8_t **data, int *len)
{
int nlen = scan_name(*data, *len);
return name_buffer;
}
+
+static int
+parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int *rlen, int cache)
+{
+ char *name = dns_consume_name(buffer, len, b, rlen);
+ struct dns_answer *a;
+ uint8_t *rdata;
+
+ if (!name) {
+ fprintf(stderr, "dropping: bad question\n");
+ return -1;
+ }
+
+ a = dns_consume_answer(b, rlen);
+ if (!a) {
+ fprintf(stderr, "dropping: bad question\n");
+ return -1;
+ }
+
+ rdata = *b;
+ if (a->rdlength > *rlen) {
+ fprintf(stderr, "dropping: bad question\n");
+ return -1;
+ }
+
+ *rlen -= a->rdlength;
+ *b += a->rdlength;
+
+ if (cache)
+ cache_answer(iface, buffer, len, name, a, rdata);
+
+ return 0;
+}
+
+static void
+parse_question(struct interface *iface, char *name, struct dns_question *q)
+{
+ char *host;
+
+ DBG(1, "Q -> %s %s\n", dns_type_string(q->type), name);
+
+ switch (q->type) {
+ case TYPE_ANY:
+ host = service_name("local");
+ if (!strcmp(name, host))
+ service_reply(iface, NULL);
+ break;
+
+ case TYPE_PTR:
+ service_announce_services(iface, name);
+ service_reply(iface, name);
+ break;
+
+ case TYPE_AAAA:
+ case TYPE_A:
+ host = strstr(name, ".local");
+ if (host)
+ *host = '\0';
+ if (!strcmp(hostname, name))
+ service_reply_a(iface, q->type);
+ break;
+ };
+}
+
+void
+dns_handle_packet(struct interface *iface, uint8_t *buffer, int len)
+{
+ struct dns_header *h;
+ uint8_t *b = buffer;
+ int rlen = len;
+
+ h = dns_consume_header(&b, &rlen);
+ if (!h) {
+ fprintf(stderr, "dropping: bad header\n");
+ return;
+ }
+
+ while (h->questions-- > 0) {
+ char *name = dns_consume_name(buffer, len, &b, &rlen);
+ struct dns_question *q;
+
+ if (!name) {
+ fprintf(stderr, "dropping: bad name\n");
+ return;
+ }
+
+ q = dns_consume_question(&b, &rlen);
+ if (!q) {
+ fprintf(stderr, "dropping: bad question\n");
+ return;
+ }
+
+ if (!(h->flags & FLAG_RESPONSE))
+ parse_question(iface, name, q);
+ }
+
+ if (!(h->flags & FLAG_RESPONSE))
+ return;
+
+ while (h->answers-- > 0)
+ parse_answer(iface, buffer, len, &b, &rlen, 1);
+
+ while (h->authority-- > 0)
+ parse_answer(iface, buffer, len, &b, &rlen, 0);
+
+ while (h->additional-- > 0)
+ parse_answer(iface, buffer, len, &b, &rlen, 1);
+}