[PATCH v3] ipconfig: add nameserver IPs to kernel-parameter ip=
From: Christoph Fritz <hidden>
Date: 2012-09-21 18:31:36
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documentation, kernel nfsd, sunrpc, and lockd servers, networking [general], networking [ipv4/ipv6], nfs, sunrpc, and lockd clients, the rest · Maintainers:
Jonathan Corbet, Chuck Lever, Jeff Layton, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Trond Myklebust, Anna Schumaker, Linus Torvalds
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 <redacted> Tested-by: Jan Weitzel <redacted> --- 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