1 files changed, 136 insertions, 0 deletions
diff --git a/usr.sbin/pkg/dns_utils.c b/usr.sbin/pkg/dns_utils.c
new file mode 100644
index 0000000..e88bf98
--- /dev/null
+++ b/usr.sbin/pkg/dns_utils.c
@@ -0,0 +1,136 @@
+/*-
+ * Copyright (c) 2012 Baptiste Daroussin <bapt@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification, immediately at the beginning of the file.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <stdlib.h>
+#include <string.h>
+#include <netinet/in.h>
+#include <resolv.h>
+
+#include "dns_utils.h"
+
+typedef union {
+	HEADER hdr;
+	unsigned char buf[1024];
+} dns_query;
+
+struct dns_srvinfo *
+dns_getsrvinfo(const char *zone)
+{
+	struct dns_srvinfo **res, *first;
+	unsigned char *end, *p;
+	char host[MAXHOSTNAMELEN];
+	dns_query q;
+	int len, qdcount, ancount, n, i;
+	unsigned int type, class, ttl, priority, weight, port;
+
+	if ((len = res_query(zone, C_IN, T_SRV, q.buf, sizeof(q.buf))) == -1 ||
+	    len < (int)sizeof(HEADER))
+		return (NULL);
+
+	qdcount = ntohs(q.hdr.qdcount);
+	ancount = ntohs(q.hdr.ancount);
+
+	end = q.buf + len;
+	p = q.buf + sizeof(HEADER);
+
+	while(qdcount > 0 && p < end) {
+		qdcount--;
+		if((len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN)) < 0)
+			return (NULL);
+		p += len + NS_QFIXEDSZ;
+	}
+
+	res = malloc(sizeof(struct dns_srvinfo) * ancount);
+	if (res == NULL)
+		return (NULL);
+	memset(res, 0, sizeof(struct dns_srvinfo) * ancount);
+
+	n = 0;
+	while (ancount > 0 && p < end) {
+		ancount--;
+		len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN);
+		if (len < 0) {
+			for (i = 0; i < n; i++)
+				free(res[i]);
+			free(res);
+			return NULL;
+		}
+
+		p += len;
+
+		NS_GET16(type, p);
+		NS_GET16(class, p);
+		NS_GET32(ttl, p);
+		NS_GET16(len, p);
+
+		if (type != T_SRV) {
+			p += len;
+			continue;
+		}
+
+		NS_GET16(priority, p);
+		NS_GET16(weight, p);
+		NS_GET16(port, p);
+
+		len = dn_expand(q.buf, end, p, host, MAXHOSTNAMELEN);
+		if (len < 0) {
+			for (i = 0; i < n; i++)
+				free(res[i]);
+			free(res);
+			return (NULL);
+		}
+
+		res[n] = malloc(sizeof(struct dns_srvinfo));
+		if (res[n] == NULL) {
+			for (i = 0; i < n; i++)
+				free(res[i]);
+			free(res);
+			return (NULL);
+		}
+		res[n]->type = type;
+		res[n]->class = class;
+		res[n]->ttl = ttl;
+		res[n]->priority = priority;
+		res[n]->weight = weight;
+		res[n]->port = port;
+		res[n]->next = NULL;
+		strlcpy(res[n]->host, host, MAXHOSTNAMELEN);
+
+		p += len;
+		n++;
+	}
+
+	for (i = 0; i < n - 1; i++)
+		res[i]->next = res[i + 1];
+
+	first = res[0];
+	free(res);
+
+	return (first);
+}