network: handle DNS config

If we have a dns config option, update resolv.conf

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

3 files changed, 61 insertions, 2 deletions

diff --git a/discover/network.c b/discover/network.c
index 910649e..3b01f9f 100644
--- a/discover/network.c
+++ b/discover/network.c
@@ -3,6 +3,7 @@
 #include <stdint.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 #include <sys/socket.h>
 #include <linux/if.h>
 #include <linux/netlink.h>
@@ -15,6 +16,7 @@
 #include <pb-config/pb-config.h>
 #include <system/system.h>
 
+#include "file.h"
 #include "network.h"
 
 #define HWADDR_SIZE	6
@@ -399,6 +401,59 @@ static int network_netlink_process(void *arg)
 	return 0;
 }
 
+static void network_init_dns(struct network *network)
+{
+	const struct config *config;
+	int i, rc, len;
+	bool modified;
+	char *buf;
+
+	if (network->dry_run)
+		return;
+
+	config = config_get();
+	if (!config || !config->network.n_dns_servers)
+		return;
+
+	rc = read_file(network, "/etc/resolv.conf", &buf, &len);
+
+	if (rc) {
+		buf = talloc_strdup(network, "");
+		len = 0;
+	}
+
+	modified = false;
+
+	for (i = 0; i < config->network.n_dns_servers; i++) {
+		int dns_conf_len;
+		char *dns_conf;
+
+		dns_conf = talloc_asprintf(network, "server %s\n",
+				config->network.dns_servers[i]);
+
+		if (strstr(buf, dns_conf)) {
+			talloc_free(dns_conf);
+			continue;
+		}
+
+		dns_conf_len = strlen(dns_conf);
+		buf = talloc_realloc(network, buf, char, len + dns_conf_len);
+		memcpy(buf + len, dns_conf, dns_conf_len);
+		len += dns_conf_len;
+		modified = true;
+	}
+
+	if (!modified)
+		return;
+
+	rc = replace_file("/etc/resolv.conf", buf, len);
+	if (rc) {
+		pb_log("error replacing resolv.conf: %s\n", strerror(errno));
+		return;
+	}
+
+}
+
 struct network *network_init(void *ctx, struct waitset *waitset, bool dry_run)
 {
 	struct network *network;
@@ -409,6 +464,8 @@ struct network *network_init(void *ctx, struct waitset *waitset, bool dry_run)
 	network->manual_config = false;
 	network->dry_run = dry_run;
 
+	network_init_dns(network);
+
 	rc = network_init_netlink(network);
 	if (rc)
 		goto err;
diff --git a/lib/pb-config/pb-config.c b/lib/pb-config/pb-config.c
index 5cd303b..315d990 100644
--- a/lib/pb-config/pb-config.c
+++ b/lib/pb-config/pb-config.c
@@ -26,7 +26,7 @@ static void dump_config(struct config *config)
 	pb_log(" autoboot: %s\n",
 			config->autoboot_enabled ? "enabled" : "disabled");
 
-	if (config->n_network_configs > 0)
+	if (config->network.n_interfaces || config->network.n_dns_servers)
 		pb_log(" network configuration:\n");
 
 	for (i = 0; i < config->network.n_interfaces; i++) {
@@ -53,6 +53,8 @@ static void dump_config(struct config *config)
 
 		}
 	}
+	for (i = 0; i < config->network.n_dns_servers; i++)
+		pb_log("  dns server %s\n", config->network.dns_servers[i]);
 }
 
 int config_init(void *ctx)
diff --git a/lib/pb-config/storage-powerpc-nvram.c b/lib/pb-config/storage-powerpc-nvram.c
index 734741e..3ed3c46 100644
--- a/lib/pb-config/storage-powerpc-nvram.c
+++ b/lib/pb-config/storage-powerpc-nvram.c
@@ -315,7 +315,7 @@ static void populate_network_config(struct powerpc_nvram_storage *nv,
 		if (!tok)
 			break;
 
-		if (strncmp(tok, "dns,", strlen("dns,")))
+		if (!strncasecmp(tok, "dns,", strlen("dns,")))
 			parse_one_dns_config(config, tok + strlen("dns,"));
 		else
 			parse_one_interface_config(config, tok);