X-Git-Url: https://git.archive.openwrt.org/?p=project%2Fmdnsd.git;a=blobdiff_plain;f=dns.c;h=5390fe6216097920b9ee08ad59b197950d1dcb8f;hp=5595384a544b0f86ba326629defd27a47c2a3b27;hb=4a10aa49f77351da34872b7c15c6debd13e42d2a;hpb=2ef1a8ff170ea2c81b3523283dfbc1567297a839

diff --git a/dns.c b/dns.c
index 5595384..5390fe6 100644
--- a/dns.c
+++ b/dns.c
@@ -65,10 +65,43 @@ dns_type_string(uint16_t type)
 	return "N/A";
 }
 
-void
-dns_send_question(struct uloop_fd *u, char *question, int type)
+static int
+dns_send_packet(int fd, struct iovec *iov, int iov_len)
 {
 	static size_t cmsg_data[( CMSG_SPACE(sizeof(struct in_pktinfo)) / sizeof(size_t)) + 1];
+	static struct sockaddr_in a = {
+		.sin_family = AF_INET,
+		.sin_port = htons(MCAST_PORT),
+	};
+	static struct msghdr m = {
+		.msg_name = (struct sockaddr *) &a,
+		.msg_namelen = sizeof(a),
+		.msg_control = cmsg_data,
+		.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
+	};
+	struct in_pktinfo *pkti;
+	struct cmsghdr *cmsg;
+
+	m.msg_iov = iov;
+	m.msg_iovlen = iov_len;
+
+	memset(cmsg_data, 0, sizeof(cmsg_data));
+	cmsg = CMSG_FIRSTHDR(&m);
+	cmsg->cmsg_len = m.msg_controllen;
+	cmsg->cmsg_level = IPPROTO_IP;
+	cmsg->cmsg_type = IP_PKTINFO;
+
+	pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
+	pkti->ipi_ifindex = iface_index;
+
+	a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
+
+	return sendmsg(fd, &m, 0);
+}
+
+void
+dns_send_question(struct uloop_fd *u, const char *question, int type)
+{
 	static struct dns_header h = {
 		.questions = cpu_to_be16(1),
 	};
@@ -88,23 +121,8 @@ dns_send_question(struct uloop_fd *u, char *question, int type)
 			.iov_len = sizeof(q),
 		}
 	};
-	static struct sockaddr_in a = {
-		.sin_family = AF_INET,
-		.sin_port = htons(MCAST_PORT),
-	};
-	static struct msghdr m = {
-		.msg_name = (struct sockaddr *) &a,
-		.msg_namelen = sizeof(a),
-		.msg_iov = iov,
-		.msg_iovlen = ARRAY_SIZE(iov),
-		.msg_control = cmsg_data,
-		.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo)),
-	};
-	struct in_pktinfo *pkti;
-	struct cmsghdr *cmsg;
 	int len;
 
-	a.sin_addr.s_addr = inet_addr(MCAST_ADDR);
 	q.type = __cpu_to_be16(type);
 
 	len = dn_comp(question, (void *) name_buffer, sizeof(name_buffer), NULL, NULL);
@@ -113,17 +131,7 @@ dns_send_question(struct uloop_fd *u, char *question, int type)
 
 	iov[1].iov_len = len;
 
-	memset(cmsg_data, 0, sizeof(cmsg_data));
-
-	cmsg = CMSG_FIRSTHDR(&m);
-	cmsg->cmsg_len = m.msg_controllen;
-	cmsg->cmsg_level = IPPROTO_IP;
-	cmsg->cmsg_type = IP_PKTINFO;
-
-	pkti = (struct in_pktinfo*) CMSG_DATA(cmsg);
-	pkti->ipi_ifindex = iface_index;
-
-	if (sendmsg(u->fd, &m, 0) < 0)
+	if (dns_send_packet(u->fd, iov, ARRAY_SIZE(iov)) < 0)
 		fprintf(stderr, "failed to send question\n");
 	else
 		DBG(1, "Q <- %s %s\n", dns_type_string(type), question);
@@ -149,7 +157,7 @@ dns_init_answer(void)
 }
 
 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)
@@ -161,34 +169,20 @@ dns_add_answer(int type, uint8_t *rdata, uint16_t rdlength)
 }
 
 void
-dns_send_answer(struct uloop_fd *u, char *answer)
+dns_send_answer(struct uloop_fd *u, 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 = &in;
-	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);
 
@@ -218,7 +212,7 @@ dns_send_answer(struct uloop_fd *u, char *answer)
 		DBG(1, "A <- %s %s\n", dns_type_string(dns_reply[i].type), answer);
 	}
 
-	if (sendmsg(u->fd, &m, 0) < 0)
+	if (dns_send_packet(u->fd, iov, (dns_answer_cnt * 3) + 1) < 0)
 		fprintf(stderr, "failed to send question\n");
 
 	for (i = 0; i < dns_answer_cnt; i++) {
@@ -229,7 +223,7 @@ dns_send_answer(struct uloop_fd *u, char *answer)
 }
 
 static int
-scan_name(uint8_t *buffer, int len)
+scan_name(const uint8_t *buffer, int len)
 {
 	int offset = 0;
 
@@ -312,7 +306,7 @@ dns_consume_answer(uint8_t **data, int *len)
 }
 
 char*
-dns_consume_name(uint8_t *base, int blen, uint8_t **data, int *len)
+dns_consume_name(const uint8_t *base, int blen, uint8_t **data, int *len)
 {
 	int nlen = scan_name(*data, *len);