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: Christoph Fritz <chf.fritz@xxxxxxxxxxxxxx> Tested-by: Jan Weitzel <j.weitzel@xxxxxxxxx> --- v2: - fix indent v3: - fix docu: add new arguments to option "ip=" --- Documentation/filesystems/nfs/nfsroot.txt | 10 ++++++- net/ipv4/ipconfig.c | 39 ++++++++++++++++++++++++++-- 2 files changed, 45 insertions(+), 4 deletions(-) diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt index ffdd9d8..2d66ed6 100644 --- a/Documentation/filesystems/nfs/nfsroot.txt +++ b/Documentation/filesystems/nfs/nfsroot.txt @@ -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 diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c index 67e8a6b..1c0e7e0 100644 --- a/net/ipv4/ipconfig.c +++ b/net/ipv4/ipconfig.c @@ -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; -- 1.7.2.5 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html