clean up hostname handling, make service_name() static

[project/mdnsd.git] / dns.c

diff --git a/dns.c b/dns.c
index a646024..c8d2100 100644 (file)
--- a/dns.c
+++ b/dns.c
@@ -35,9 +35,10 @@
 #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*
@@ -136,7 +137,7 @@ dns_add_answer(int type, const uint8_t *rdata, uint16_t rdlength)
 }
 
 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 };
@@ -179,7 +180,7 @@ dns_send_answer(struct uloop_fd *u, const char *answer)
                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++) {
@@ -211,7 +212,7 @@ scan_name(const uint8_t *buffer, int len)
        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;
@@ -232,7 +233,7 @@ dns_consume_header(uint8_t **data, int *len)
        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;
@@ -253,7 +254,7 @@ dns_consume_question(uint8_t **data, int *len)
        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;
@@ -272,7 +273,7 @@ dns_consume_answer(uint8_t **data, int *len)
        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);
@@ -290,3 +291,110 @@ dns_consume_name(const uint8_t *base, int blen, uint8_t **data, int *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:
+               if (!strcmp(name, mdns_hostname_local))
+                       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(mdns_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);
+}