net/ipv4/ipconfig.c: Add support for multiple nameservers.

net/ipv4/ipconfig.c

@@ -26,6 +26,9 @@
  *
  *  Merged changes from 2.2.19 into 2.4.3
  *              -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
+ *
+ *  Multipe Nameservers in /proc/net/pnp
+ *              --  Josef Siemes <jsiemes@web.de>, Aug 2002
  */
 
 #include <linux/config.h>
@@ -91,6 +94,8 @@
 #define CONF_TIMEOUT_RANDOM	(HZ)	/* Maximum amount of randomization */
 #define CONF_TIMEOUT_MULT	*7/4	/* Rate of timeout growth */
 #define CONF_TIMEOUT_MAX	(HZ*30)	/* Maximum allowed timeout */
+#define CONF_NAMESERVERS_MAX   3       /* Maximum number of nameservers  
+                                           - '3' from resolv.h */
 
 
 /*
@@ -132,7 +137,7 @@ u8 root_server_path[256] __initdata = { 0, };	/* Path to mount as root */
 /* Persistent data: */
 
 int ic_proto_used;			/* Protocol used, if any */
-u32 ic_nameserver = INADDR_NONE;	/* DNS Server IP address */
+u32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
 u8 ic_domain[64];		/* DNS (not NIS) domain name */
 
 /*
@@ -625,6 +630,11 @@ static void __init ic_bootp_init_ext(u8 *e)
  */
 static inline void ic_bootp_init(void)
 {
+	int i;
+
+	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
+		ic_nameservers[i] = INADDR_NONE;
+
 	dev_add_pack(&bootp_packet_type);
 }
 
@@ -729,6 +739,9 @@ static int __init ic_bootp_string(char *dest, char *src, int len, int max)
  */
 static void __init ic_do_bootp_ext(u8 *ext)
 {
+       u8 servers;
+       int i;
+
 #ifdef IPCONFIG_DEBUG
 	u8 *c;
 
@@ -748,8 +761,13 @@ static void __init ic_do_bootp_ext(u8 *ext)
 				memcpy(&ic_gateway, ext+1, 4);
 			break;
 		case 6:		/* DNS server */
-			if (ic_nameserver == INADDR_NONE)
-				memcpy(&ic_nameserver, ext+1, 4);
+			servers= *ext/4;
+			if (servers > CONF_NAMESERVERS_MAX)
+				servers = CONF_NAMESERVERS_MAX;
+			for (i = 0; i < servers; i++) {
+				if (ic_nameservers[i] == INADDR_NONE)
+					memcpy(&ic_nameservers[i], ext+1+4*i, 4);
+			}
 			break;
 		case 12:	/* Host name */
 			ic_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN);
@@ -914,8 +932,8 @@ static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, str
 	ic_servaddr = b->server_ip;
 	if (ic_gateway == INADDR_NONE && b->relay_ip)
 		ic_gateway = b->relay_ip;
-	if (ic_nameserver == INADDR_NONE)
-		ic_nameserver = ic_servaddr;
+	if (ic_nameservers[0] == INADDR_NONE)
+		ic_nameservers[0] = ic_servaddr;
 	ic_got_reply = IC_BOOTP;
 
 drop:
@@ -1078,6 +1096,7 @@ static int pnp_get_info(char *buffer, char **start,
 			off_t offset, int length)
 {
 	int len;
+       int i;
 
 	if (ic_proto_used & IC_PROTO)
 	    sprintf(buffer, "#PROTO: %s\n",
@@ -1090,9 +1109,12 @@ static int pnp_get_info(char *buffer, char **start,
 	if (ic_domain[0])
 		len += sprintf(buffer + len,
 			       "domain %s\n", ic_domain);
-	if (ic_nameserver != INADDR_NONE)
-		len += sprintf(buffer + len,
-			       "nameserver %u.%u.%u.%u\n", NIPQUAD(ic_nameserver));
+	for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
+		if (ic_nameservers[i] != INADDR_NONE)
+			len += sprintf(buffer + len,
+				       "nameserver %u.%u.%u.%u\n",
+				       NIPQUAD(ic_nameservers[i]));
+	}
 
 	if (offset > len)
 		offset = len;