1 files changed, 105 insertions, 0 deletions
diff --git a/resolve_host.c b/resolve_host.c
new file mode 100644
index 0000000..7687503
--- /dev/null
+++ b/resolve_host.c
@@ -0,0 +1,105 @@
+/*
+ * resolving DNS hostname routine
+ *
+ * Copyright (C) 2010 Jeff Layton (jlayton@samba.org)
+ * Copyright (C) 2010 Igor Druzhinin (jaxbrigs@gmail.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif /* HAVE_CONFIG_H */
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+#include "mount.h"
+#include "util.h"
+#include "resolve_host.h"
+
+/*
+ * resolve hostname to comma-separated list of address(es)
+ */
+int resolve_host(const char *host, char *addrstr)
+{
+	int rc;
+	/* 10 for max width of decimal scopeid */
+	char tmpbuf[NI_MAXHOST + 1 + 10 + 1];
+	const char *ipaddr;
+	size_t len;
+	struct addrinfo *addrlist, *addr;
+	struct sockaddr_in *sin;
+	struct sockaddr_in6 *sin6;
+
+	rc = getaddrinfo(host, NULL, NULL, &addrlist);
+	if (rc != 0)
+		return EX_USAGE;
+
+	addr = addrlist;
+	while (addr) {
+		/* skip non-TCP entries */
+		if (addr->ai_socktype != SOCK_STREAM ||
+		    addr->ai_protocol != IPPROTO_TCP) {
+			addr = addr->ai_next;
+			continue;
+		}
+
+		switch (addr->ai_addr->sa_family) {
+		case AF_INET6:
+			sin6 = (struct sockaddr_in6 *)addr->ai_addr;
+			ipaddr = inet_ntop(AF_INET6, &sin6->sin6_addr, tmpbuf,
+					   sizeof(tmpbuf));
+			if (!ipaddr) {
+				rc = EX_SYSERR;
+				goto resolve_host_out;
+			}
+
+			if (sin6->sin6_scope_id) {
+				len = strnlen(tmpbuf, sizeof(tmpbuf));
+				ipaddr = tmpbuf + len;
+				snprintf(tmpbuf, sizeof(tmpbuf) - len, "%%%u",
+					 sin6->sin6_scope_id);
+			}
+			break;
+		case AF_INET:
+			sin = (struct sockaddr_in *)addr->ai_addr;
+			ipaddr = inet_ntop(AF_INET, &sin->sin_addr, tmpbuf,
+					   sizeof(tmpbuf));
+			if (!ipaddr) {
+				rc = EX_SYSERR;
+				goto resolve_host_out;
+			}
+
+			break;
+		default:
+			addr = addr->ai_next;
+			continue;
+		}
+
+		if (addr == addrlist)
+			*addrstr = '\0';
+		else
+			strlcat(addrstr, ",", MAX_ADDR_LIST_LEN);
+
+		strlcat(addrstr, tmpbuf, MAX_ADDR_LIST_LEN);
+		addr = addr->ai_next;
+	}
+
+resolve_host_out:
+	freeaddrinfo(addrlist);
+	return rc;
+}