Commit 5e953778 authored by Christoph Fritz's avatar Christoph Fritz Committed by David S. Miller
Browse files

ipconfig: add nameserver IPs to kernel-parameter ip= 



On small systems (e.g. embedded ones) IP addresses are often configured
by bootloaders and get assigned to kernel via parameter "ip=".  If set to
"ip=dhcp", even nameserver entries from DHCP daemons are handled. These
entries exported in /proc/net/pnp are commonly linked by /etc/resolv.conf.

To configure nameservers for networks without DHCP, this patch adds option
<dns0-ip> and <dns1-ip> to kernel-parameter 'ip='.

Signed-off-by: default avatarChristoph Fritz <chf.fritz@googlemail.com>
Tested-by: default avatarJan Weitzel <j.weitzel@phytec.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 42d94dcb

Documentation/filesystems/nfs/nfsroot.txt

+9 −1
Original line number Diff line number Diff line
@@ -78,7 +78,8 @@ nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>] 
			flags		= hard, nointr, noposix, cto, ac





ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>

ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:

   <dns0-ip>:<dns1-ip>



  This parameter tells the kernel how to configure IP addresses of devices

  and also how to set up the IP routing table. It was originally called
@@ -158,6 +159,13 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf> 


                Default: any



  <dns0-ip>	IP address of first nameserver.

		Value gets exported by /proc/net/pnp which is often linked

		on embedded systems by /etc/resolv.conf.



  <dns1-ip>	IP address of secound nameserver.

		Same as above.





nfsrootdebug

net/ipv4/ipconfig.c

+36 −3
Original line number Diff line number Diff line
@@ -743,14 +743,22 @@ static void __init ic_bootp_init_ext(u8 *e) 




/*

 *  Initialize the DHCP/BOOTP mechanism.

 *  Predefine Nameservers

 */

static inline void __init ic_bootp_init(void)

static inline void __init ic_nameservers_predef(void)

{

	int i;



	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)

		ic_nameservers[i] = NONE;

}



/*

 *  Initialize the DHCP/BOOTP mechanism.

 */

static inline void __init ic_bootp_init(void)

{

	ic_nameservers_predef();



	dev_add_pack(&bootp_packet_type);

}
@@ -1379,6 +1387,7 @@ static int __init ip_auto_config(void) 
	int retries = CONF_OPEN_RETRIES;

#endif

	int err;

	unsigned int i;



#ifdef CONFIG_PROC_FS

	proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
@@ -1499,7 +1508,15 @@ static int __init ip_auto_config(void) 
		&ic_servaddr, &root_server_addr, root_server_path);

	if (ic_dev_mtu)

		pr_cont(", mtu=%d", ic_dev_mtu);

	pr_cont("\n");

	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)

		if (ic_nameservers[i] != NONE) {

			pr_info("     nameserver%u=%pI4",

				i, &ic_nameservers[i]);

			break;

		}

	for (i++; i < CONF_NAMESERVERS_MAX; i++)

		if (ic_nameservers[i] != NONE)

			pr_cont(", nameserver%u=%pI4\n", i, &ic_nameservers[i]);

#endif /* !SILENT */



	return 0;
@@ -1570,6 +1587,8 @@ static int __init ip_auto_config_setup(char *addrs) 
		return 1;

	}



	ic_nameservers_predef();



	/* Parse string for static IP assignment.  */

	ip = addrs;

	while (ip && *ip) {
@@ -1613,6 +1632,20 @@ static int __init ip_auto_config_setup(char *addrs) 
					ic_enable = 0;

				}

				break;

			case 7:

				if (CONF_NAMESERVERS_MAX >= 1) {

					ic_nameservers[0] = in_aton(ip);

					if (ic_nameservers[0] == ANY)

						ic_nameservers[0] = NONE;

				}

				break;

			case 8:

				if (CONF_NAMESERVERS_MAX >= 2) {

					ic_nameservers[1] = in_aton(ip);

					if (ic_nameservers[1] == ANY)

						ic_nameservers[1] = NONE;

				}

				break;

			}

		}

		ip = cp;

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