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Diffstat (limited to 'net/ipv4/ipconfig.c')
-rw-r--r--net/ipv4/ipconfig.c150
1 files changed, 139 insertions, 11 deletions
diff --git a/net/ipv4/ipconfig.c b/net/ipv4/ipconfig.c
index bbcbcc113d19..88212615bf4c 100644
--- a/net/ipv4/ipconfig.c
+++ b/net/ipv4/ipconfig.c
@@ -28,6 +28,9 @@
*
* Multiple Nameservers in /proc/net/pnp
* -- Josef Siemes <jsiemes@web.de>, Aug 2002
+ *
+ * NTP servers in /proc/net/ipconfig/ntp_servers
+ * -- Chris Novakovic <chris@chrisn.me.uk>, April 2018
*/
#include <linux/types.h>
@@ -93,6 +96,7 @@
#define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */
#define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
- '3' from resolv.h */
+#define CONF_NTP_SERVERS_MAX 3 /* Maximum number of NTP servers */
#define NONE cpu_to_be32(INADDR_NONE)
#define ANY cpu_to_be32(INADDR_ANY)
@@ -152,6 +156,7 @@ static int ic_proto_used; /* Protocol used, if any */
#define ic_proto_used 0
#endif
static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
+static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
static u8 ic_domain[64]; /* DNS (not NIS) domain name */
/*
@@ -576,6 +581,15 @@ static inline void __init ic_nameservers_predef(void)
ic_nameservers[i] = NONE;
}
+/* Predefine NTP servers */
+static inline void __init ic_ntp_servers_predef(void)
+{
+ int i;
+
+ for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
+ ic_ntp_servers[i] = NONE;
+}
+
/*
* DHCP/BOOTP support.
*/
@@ -671,6 +685,7 @@ ic_dhcp_init_options(u8 *options, struct ic_device *d)
17, /* Boot path */
26, /* MTU */
40, /* NIS domain name */
+ 42, /* NTP servers */
};
*e++ = 55; /* Parameter request list */
@@ -721,9 +736,11 @@ static void __init ic_bootp_init_ext(u8 *e)
*e++ = 3; /* Default gateway request */
*e++ = 4;
e += 4;
- *e++ = 5; /* Name server request */
- *e++ = 8;
- e += 8;
+#if CONF_NAMESERVERS_MAX > 0
+ *e++ = 6; /* (DNS) name server request */
+ *e++ = 4 * CONF_NAMESERVERS_MAX;
+ e += 4 * CONF_NAMESERVERS_MAX;
+#endif
*e++ = 12; /* Host name request */
*e++ = 32;
e += 32;
@@ -748,7 +765,13 @@ static void __init ic_bootp_init_ext(u8 *e)
*/
static inline void __init ic_bootp_init(void)
{
+ /* Re-initialise all name servers and NTP servers to NONE, in case any
+ * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
+ * any IP addresses specified there will already have been decoded but
+ * are no longer needed
+ */
ic_nameservers_predef();
+ ic_ntp_servers_predef();
dev_add_pack(&bootp_packet_type);
}
@@ -912,6 +935,15 @@ static void __init ic_do_bootp_ext(u8 *ext)
ic_bootp_string(utsname()->domainname, ext+1, *ext,
__NEW_UTS_LEN);
break;
+ case 42: /* NTP servers */
+ servers = *ext / 4;
+ if (servers > CONF_NTP_SERVERS_MAX)
+ servers = CONF_NTP_SERVERS_MAX;
+ for (i = 0; i < servers; i++) {
+ if (ic_ntp_servers[i] == NONE)
+ memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
+ }
+ break;
}
}
@@ -1257,7 +1289,10 @@ static int __init ic_dynamic(void)
#endif /* IPCONFIG_DYNAMIC */
#ifdef CONFIG_PROC_FS
+/* proc_dir_entry for /proc/net/ipconfig */
+static struct proc_dir_entry *ipconfig_dir;
+/* Name servers: */
static int pnp_seq_show(struct seq_file *seq, void *v)
{
int i;
@@ -1282,6 +1317,62 @@ static int pnp_seq_show(struct seq_file *seq, void *v)
&ic_servaddr);
return 0;
}
+
+/* Create the /proc/net/ipconfig directory */
+static int __init ipconfig_proc_net_init(void)
+{
+ ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
+ if (!ipconfig_dir)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/* Create a new file under /proc/net/ipconfig */
+static int ipconfig_proc_net_create(const char *name,
+ const struct file_operations *fops)
+{
+ char *pname;
+ struct proc_dir_entry *p;
+
+ if (!ipconfig_dir)
+ return -ENOMEM;
+
+ pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
+ if (!pname)
+ return -ENOMEM;
+
+ p = proc_create(pname, 0444, init_net.proc_net, fops);
+ kfree(pname);
+ if (!p)
+ return -ENOMEM;
+
+ return 0;
+}
+
+/* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
+static int ntp_servers_seq_show(struct seq_file *seq, void *v)
+{
+ int i;
+
+ for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
+ if (ic_ntp_servers[i] != NONE)
+ seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
+ }
+ return 0;
+}
+
+static int ntp_servers_seq_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, ntp_servers_seq_show, NULL);
+}
+
+static const struct file_operations ntp_servers_seq_fops = {
+ .open = ntp_servers_seq_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
#endif /* CONFIG_PROC_FS */
/*
@@ -1356,8 +1447,20 @@ static int __init ip_auto_config(void)
int err;
unsigned int i;
+ /* Initialise all name servers and NTP servers to NONE (but only if the
+ * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
+ * otherwise we'll overwrite the IP addresses specified there)
+ */
+ if (ic_set_manually == 0) {
+ ic_nameservers_predef();
+ ic_ntp_servers_predef();
+ }
+
#ifdef CONFIG_PROC_FS
proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
+
+ if (ipconfig_proc_net_init() == 0)
+ ipconfig_proc_net_create("ntp_servers", &ntp_servers_seq_fops);
#endif /* CONFIG_PROC_FS */
if (!ic_enable)
@@ -1469,16 +1572,32 @@ 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);
- for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
+ /* Name servers (if any): */
+ for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
if (ic_nameservers[i] != NONE) {
- pr_cont(" nameserver%u=%pI4",
- i, &ic_nameservers[i]);
- break;
+ if (i == 0)
+ pr_info(" nameserver%u=%pI4",
+ i, &ic_nameservers[i]);
+ else
+ pr_cont(", nameserver%u=%pI4",
+ i, &ic_nameservers[i]);
}
- for (i++; i < CONF_NAMESERVERS_MAX; i++)
- if (ic_nameservers[i] != NONE)
- pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]);
- pr_cont("\n");
+ if (i + 1 == CONF_NAMESERVERS_MAX)
+ pr_cont("\n");
+ }
+ /* NTP servers (if any): */
+ for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
+ if (ic_ntp_servers[i] != NONE) {
+ if (i == 0)
+ pr_info(" ntpserver%u=%pI4",
+ i, &ic_ntp_servers[i]);
+ else
+ pr_cont(", ntpserver%u=%pI4",
+ i, &ic_ntp_servers[i]);
+ }
+ if (i + 1 == CONF_NTP_SERVERS_MAX)
+ pr_cont("\n");
+ }
#endif /* !SILENT */
/*
@@ -1576,7 +1695,9 @@ static int __init ip_auto_config_setup(char *addrs)
return 1;
}
+ /* Initialise all name servers and NTP servers to NONE */
ic_nameservers_predef();
+ ic_ntp_servers_predef();
/* Parse string for static IP assignment. */
ip = addrs;
@@ -1635,6 +1756,13 @@ static int __init ip_auto_config_setup(char *addrs)
ic_nameservers[1] = NONE;
}
break;
+ case 9:
+ if (CONF_NTP_SERVERS_MAX >= 1) {
+ ic_ntp_servers[0] = in_aton(ip);
+ if (ic_ntp_servers[0] == ANY)
+ ic_ntp_servers[0] = NONE;
+ }
+ break;
}
}
ip = cp;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.