1 files changed, 123 insertions, 0 deletions
diff --git a/libcli/dns/resolvconf.c b/libcli/dns/resolvconf.c
new file mode 100644
index 0000000..5cf8b4e
--- /dev/null
+++ b/libcli/dns/resolvconf.c
@@ -0,0 +1,123 @@
+/*
+ *  Unix SMB/CIFS implementation.
+ *  Internal DNS query structures
+ *  Copyright (C) Volker Lendecke 2018
+ *
+ *  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/>.
+ */
+
+#include "replace.h"
+#include <stdio.h>
+#include <errno.h>
+#include "libcli/dns/resolvconf.h"
+#include "lib/util/memory.h"
+
+int parse_resolvconf_fp(
+	FILE *fp,
+	TALLOC_CTX *mem_ctx,
+	char ***pnameservers,
+	size_t *pnum_nameservers)
+{
+	char *line = NULL;
+	size_t len = 0;
+	char **nameservers = NULL;
+	size_t num_nameservers = 0;
+	int ret = 0;
+
+	while (true) {
+		char *saveptr = NULL, *option = NULL, *ns = NULL;
+		char **tmp = NULL;
+		ssize_t n = 0;
+
+		n = getline(&line, &len, fp);
+		if (n < 0) {
+			if (!feof(fp)) {
+				/* real error */
+				ret = errno;
+			}
+			break;
+		}
+		if ((n > 0) && (line[n-1] == '\n')) {
+			line[n-1] = '\0';
+		}
+
+		if ((line[0] == '#') || (line[0] == ';')) {
+			continue;
+		}
+
+		option = strtok_r(line, " \t", &saveptr);
+		if (option == NULL) {
+			continue;
+		}
+
+		if (strcmp(option, "nameserver") != 0) {
+			continue;
+		}
+
+		ns = strtok_r(NULL, " \t", &saveptr);
+		if (ns == NULL) {
+			continue;
+		}
+
+		tmp = talloc_realloc(
+			mem_ctx,
+			nameservers,
+			char *,
+			num_nameservers+1);
+		if (tmp == NULL) {
+			ret = ENOMEM;
+			break;
+		}
+		nameservers = tmp;
+
+		nameservers[num_nameservers] = talloc_strdup(nameservers, ns);
+		if (nameservers[num_nameservers] == NULL) {
+			ret = ENOMEM;
+			break;
+		}
+		num_nameservers += 1;
+	}
+
+	SAFE_FREE(line);
+
+	if (ret == 0) {
+		*pnameservers = nameservers;
+		*pnum_nameservers = num_nameservers;
+	} else {
+		TALLOC_FREE(nameservers);
+	}
+
+	return ret;
+}
+
+int parse_resolvconf(
+	const char *resolvconf,
+	TALLOC_CTX *mem_ctx,
+	char ***pnameservers,
+	size_t *pnum_nameservers)
+{
+	FILE *fp;
+	int ret;
+
+	fp = fopen(resolvconf ? resolvconf : "/etc/resolv.conf", "r");
+	if (fp == NULL) {
+		return errno;
+	}
+
+	ret = parse_resolvconf_fp(fp, mem_ctx, pnameservers, pnum_nameservers);
+
+	fclose(fp);
+
+	return ret;
+}