#include <libubox/uloop.h>
#include <libubox/usock.h>
+#include <libubox/utils.h>
#include "announce.h"
#include "util.h"
#include "dns.h"
+#include "cache.h"
+#include "service.h"
+#include "interface.h"
-char *rdata_buffer;
-static char *name_buffer;
+static char name_buffer[MAX_NAME_LEN + 1];
const char*
dns_type_string(uint16_t type)
}
void
-dns_send_question(struct uloop_fd *u, char *question, int type)
+dns_send_question(struct interface *iface, const char *question, int type)
{
- unsigned char buffer[MAX_NAME_LEN];
- struct dns_header h = { 0 };
- struct dns_question q = { 0 };
- struct msghdr m = { 0 };
- struct iovec iov[3] = { {0}, {0}, {0} };
- struct sockaddr_in a = { 0 };
+ static struct dns_header h = {
+ .questions = cpu_to_be16(1),
+ };
+ static struct dns_question q = {
+ .class = cpu_to_be16(1),
+ };
+ static struct iovec iov[] = {
+ {
+ .iov_base = &h,
+ .iov_len = sizeof(h),
+ },
+ {
+ .iov_base = name_buffer,
+ },
+ {
+ .iov_base = &q,
+ .iov_len = sizeof(q),
+ }
+ };
int len;
- a.sin_family = AF_INET;
- a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
- a.sin_port = htons(MCAST_PORT);
-
- h.questions = __cpu_to_be16(1);
q.type = __cpu_to_be16(type);
- q.class = __cpu_to_be16(1);
- len = dn_comp(question, buffer, MAX_NAME_LEN, NULL, NULL);
+ len = dn_comp(question, (void *) name_buffer, sizeof(name_buffer), NULL, NULL);
if (len < 1)
return;
- m.msg_name = &a;
- m.msg_namelen = sizeof(struct sockaddr_in);
- m.msg_iov = iov;
- m.msg_iovlen = 3;
-
- iov[0].iov_base = &h;
- iov[0].iov_len = sizeof(struct dns_header);
-
- iov[1].iov_base = buffer;
iov[1].iov_len = len;
- iov[2].iov_base = &q;
- iov[2].iov_len = sizeof(struct dns_question);
-
- if (sendmsg(u->fd, &m, 0) < 0)
+ if (interface_send_packet(iface, iov, ARRAY_SIZE(iov)) < 0)
fprintf(stderr, "failed to send question\n");
else
DBG(1, "Q <- %s %s\n", dns_type_string(type), question);
}
void
-dns_add_answer(int type, uint8_t *rdata, uint16_t rdlength)
+dns_add_answer(int type, const uint8_t *rdata, uint16_t rdlength)
{
struct dns_reply *a = &dns_reply[dns_answer_cnt];
if (dns_answer_cnt == MAX_ANSWER)
}
void
-dns_send_answer(struct uloop_fd *u, char *answer)
+dns_send_answer(struct interface *iface, const char *answer)
{
uint8_t buffer[256];
struct dns_header h = { 0 };
- struct msghdr m = { 0 };
struct iovec *iov;
- struct sockaddr_in in = { 0 };
int len, i;
if (!dns_answer_cnt)
return;
- in.sin_family = AF_INET;
- in.sin_addr.s_addr = inet_addr(MCAST_ADDR);
- in.sin_port = htons(MCAST_PORT);
-
h.answers = __cpu_to_be16(dns_answer_cnt);
h.flags = __cpu_to_be16(0x8400);
- iov = malloc(sizeof(struct iovec) * ((dns_answer_cnt * 3) + 1));
- if (!iov)
- return;
-
- m.msg_name = ∈
- m.msg_namelen = sizeof(struct sockaddr_in);
- m.msg_iov = iov;
- m.msg_iovlen = (dns_answer_cnt * 3) + 1;
-
+ iov = alloca(sizeof(struct iovec) * ((dns_answer_cnt * 3) + 1));
iov[0].iov_base = &h;
iov[0].iov_len = sizeof(struct dns_header);
DBG(1, "A <- %s %s\n", dns_type_string(dns_reply[i].type), answer);
}
- if (sendmsg(u->fd, &m, 0) < 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++) {
}
static int
-scan_name(uint8_t *buffer, int len)
+scan_name(const uint8_t *buffer, int len)
{
int offset = 0;
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*
-dns_consume_name(uint8_t *base, int blen, uint8_t **data, int *len)
+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;
}
-int
-dns_init(void)
+static int
+parse_answer(struct interface *iface, uint8_t *buffer, int len, uint8_t **b, int *rlen, int cache)
{
- name_buffer = malloc(MAX_NAME_LEN + 1);
- rdata_buffer = malloc(MAX_DATA_LEN + 1);
+ 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;
+ }
- if (!name_buffer || !rdata_buffer)
+ rdata = *b;
+ if (a->rdlength > *rlen) {
+ fprintf(stderr, "dropping: bad question\n");
return -1;
+ }
+
+ *rlen -= a->rdlength;
+ *b += a->rdlength;
- memset(name_buffer, 0, MAX_NAME_LEN + 1);
- memset(rdata_buffer, 0, MAX_NAME_LEN + 1);
+ 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_cleanup(void)
+dns_handle_packet(struct interface *iface, uint8_t *buffer, int len)
{
- free(name_buffer);
- free(rdata_buffer);
+ 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);
}