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linux/net/ipv4/ipconfig.c
Pavel Emelyanov 988b705077 [ARP]: Introduce the arp_hdr_len helper. 
There are some place, that calculate the ARP header length. These
calculations are correct, but 
 a) some operate with "magic" constants,
 b) enlarge the code length (sometimes at the cost of coding style),
 c) are not informative from the first glance.

The proposal is to introduce a helper, that includes all the good
sides of these calculations.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-03 12:20:57 -08:00

1539 lines
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/*
* $Id: ipconfig.c,v 1.46 2002/02/01 22:01:04 davem Exp $
*
* Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
* user-supplied information to configure own IP address and routes.
*
* Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
*
* Derived from network configuration code in fs/nfs/nfsroot.c,
* originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
*
* BOOTP rewritten to construct and analyse packets itself instead
* of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
* -- MJ, December 1998
*
* Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
* initialization scheme.
* - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
*
* DHCP support added. To users this looks like a whole separate
* protocol, but we know it's just a bag on the side of BOOTP.
* -- Chip Salzenberg <chip@valinux.com>, May 2000
*
* Ported DHCP support from 2.2.16 to 2.4.0-test4
* -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
*
* Merged changes from 2.2.19 into 2.4.3
* -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
*
* Multiple Nameservers in /proc/net/pnp
* -- Josef Siemes <jsiemes@web.de>, Aug 2002
*/
#include <linux/types.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/utsname.h>
#include <linux/in.h>
#include <linux/if.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/netdevice.h>
#include <linux/if_arp.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/socket.h>
#include <linux/route.h>
#include <linux/udp.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/major.h>
#include <linux/root_dev.h>
#include <linux/delay.h>
#include <linux/nfs_fs.h>
#include <net/net_namespace.h>
#include <net/arp.h>
#include <net/ip.h>
#include <net/ipconfig.h>
#include <net/route.h>
#include <asm/uaccess.h>
#include <net/checksum.h>
#include <asm/processor.h>
/* Define this to allow debugging output */
#undef IPCONFIG_DEBUG
#ifdef IPCONFIG_DEBUG
#define DBG(x) printk x
#else
#define DBG(x) do { } while(0)
#endif
#if defined(CONFIG_IP_PNP_DHCP)
#define IPCONFIG_DHCP
#endif
#if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
#define IPCONFIG_BOOTP
#endif
#if defined(CONFIG_IP_PNP_RARP)
#define IPCONFIG_RARP
#endif
#if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
#define IPCONFIG_DYNAMIC
#endif
/* Define the friendly delay before and after opening net devices */
#define CONF_PRE_OPEN 500 /* Before opening: 1/2 second */
#define CONF_POST_OPEN 1 /* After opening: 1 second */
/* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
#define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
#define CONF_SEND_RETRIES 6 /* Send six requests per open */
#define CONF_INTER_TIMEOUT (HZ/2) /* Inter-device timeout: 1/2 second */
#define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */
#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 */
#define NONE __constant_htonl(INADDR_NONE)
/*
* Public IP configuration
*/
/* This is used by platforms which might be able to set the ipconfig
* variables using firmware environment vars. If this is set, it will
* ignore such firmware variables.
*/
int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
static int ic_enable __initdata = 0; /* IP config enabled? */
/* Protocol choice */
int ic_proto_enabled __initdata = 0
#ifdef IPCONFIG_BOOTP
| IC_BOOTP
#endif
#ifdef CONFIG_IP_PNP_DHCP
| IC_USE_DHCP
#endif
#ifdef IPCONFIG_RARP
| IC_RARP
#endif
;
static int ic_host_name_set __initdata = 0; /* Host name set by us? */
__be32 ic_myaddr = NONE; /* My IP address */
static __be32 ic_netmask = NONE; /* Netmask for local subnet */
__be32 ic_gateway = NONE; /* Gateway IP address */
__be32 ic_servaddr = NONE; /* Boot server IP address */
__be32 root_server_addr = NONE; /* Address of NFS server */
u8 root_server_path[256] = { 0, }; /* Path to mount as root */
/* vendor class identifier */
static char vendor_class_identifier[253] __initdata;
/* Persistent data: */
static int ic_proto_used; /* Protocol used, if any */
static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
static u8 ic_domain[64]; /* DNS (not NIS) domain name */
/*
* Private state.
*/
/* Name of user-selected boot device */
static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
/* Protocols supported by available interfaces */
static int ic_proto_have_if __initdata = 0;
#ifdef IPCONFIG_DYNAMIC
static DEFINE_SPINLOCK(ic_recv_lock);
static volatile int ic_got_reply __initdata = 0; /* Proto(s) that replied */
#endif
#ifdef IPCONFIG_DHCP
static int ic_dhcp_msgtype __initdata = 0; /* DHCP msg type received */
#endif
/*
* Network devices
*/
struct ic_device {
struct ic_device *next;
struct net_device *dev;
unsigned short flags;
short able;
__be32 xid;
};
static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
static struct net_device *ic_dev __initdata = NULL; /* Selected device */
static int __init ic_open_devs(void)
{
struct ic_device *d, **last;
struct net_device *dev;
unsigned short oflags;
last = &ic_first_dev;
rtnl_lock();
/* bring loopback device up first */
for_each_netdev(&init_net, dev) {
if (!(dev->flags & IFF_LOOPBACK))
continue;
if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
}
for_each_netdev(&init_net, dev) {
if (dev->flags & IFF_LOOPBACK)
continue;
if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
(!(dev->flags & IFF_LOOPBACK) &&
(dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
strncmp(dev->name, "dummy", 5))) {
int able = 0;
if (dev->mtu >= 364)
able |= IC_BOOTP;
else
printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
if (!(dev->flags & IFF_NOARP))
able |= IC_RARP;
able &= ic_proto_enabled;
if (ic_proto_enabled && !able)
continue;
oflags = dev->flags;
if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
continue;
}
if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
rtnl_unlock();
return -1;
}
d->dev = dev;
*last = d;
last = &d->next;
d->flags = oflags;
d->able = able;
if (able & IC_BOOTP)
get_random_bytes(&d->xid, sizeof(__be32));
else
d->xid = 0;
ic_proto_have_if |= able;
DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
dev->name, able, d->xid));
}
}
rtnl_unlock();
*last = NULL;
if (!ic_first_dev) {
if (user_dev_name[0])
printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
else
printk(KERN_ERR "IP-Config: No network devices available.\n");
return -1;
}
return 0;
}
static void __init ic_close_devs(void)
{
struct ic_device *d, *next;
struct net_device *dev;
rtnl_lock();
next = ic_first_dev;
while ((d = next)) {
next = d->next;
dev = d->dev;
if (dev != ic_dev) {
DBG(("IP-Config: Downing %s\n", dev->name));
dev_change_flags(dev, d->flags);
}
kfree(d);
}
rtnl_unlock();
}
/*
* Interface to various network functions.
*/
static inline void
set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
{
sin->sin_family = AF_INET;
sin->sin_addr.s_addr = addr;
sin->sin_port = port;
}
static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
{
int res;
mm_segment_t oldfs = get_fs();
set_fs(get_ds());
res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
set_fs(oldfs);
return res;
}
static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
{
int res;
mm_segment_t oldfs = get_fs();
set_fs(get_ds());
res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
set_fs(oldfs);
return res;
}
/*
* Set up interface addresses and routes.
*/
static int __init ic_setup_if(void)
{
struct ifreq ir;
struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
int err;
memset(&ir, 0, sizeof(ir));
strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
set_sockaddr(sin, ic_myaddr, 0);
if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
return -1;
}
set_sockaddr(sin, ic_netmask, 0);
if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
return -1;
}
set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
return -1;
}
return 0;
}
static int __init ic_setup_routes(void)
{
/* No need to setup device routes, only the default route... */
if (ic_gateway != NONE) {
struct rtentry rm;
int err;
memset(&rm, 0, sizeof(rm));
if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
return -1;
}
set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
rm.rt_flags = RTF_UP | RTF_GATEWAY;
if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
return -1;
}
}
return 0;
}
/*
* Fill in default values for all missing parameters.
*/
static int __init ic_defaults(void)
{
/*
* At this point we have no userspace running so need not
* claim locks on system_utsname
*/
if (!ic_host_name_set)
sprintf(init_utsname()->nodename, "%u.%u.%u.%u", NIPQUAD(ic_myaddr));
if (root_server_addr == NONE)
root_server_addr = ic_servaddr;
if (ic_netmask == NONE) {
if (IN_CLASSA(ntohl(ic_myaddr)))
ic_netmask = htonl(IN_CLASSA_NET);
else if (IN_CLASSB(ntohl(ic_myaddr)))
ic_netmask = htonl(IN_CLASSB_NET);
else if (IN_CLASSC(ntohl(ic_myaddr)))
ic_netmask = htonl(IN_CLASSC_NET);
else {
printk(KERN_ERR "IP-Config: Unable to guess netmask for address %u.%u.%u.%u\n",
NIPQUAD(ic_myaddr));
return -1;
}
printk("IP-Config: Guessing netmask %u.%u.%u.%u\n", NIPQUAD(ic_netmask));
}
return 0;
}
/*
* RARP support.
*/
#ifdef IPCONFIG_RARP
static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
static struct packet_type rarp_packet_type __initdata = {
.type = __constant_htons(ETH_P_RARP),
.func = ic_rarp_recv,
};
static inline void ic_rarp_init(void)
{
dev_add_pack(&rarp_packet_type);
}
static inline void ic_rarp_cleanup(void)
{
dev_remove_pack(&rarp_packet_type);
}
/*
* Process received RARP packet.
*/
static int __init
ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
struct arphdr *rarp;
unsigned char *rarp_ptr;
__be32 sip, tip;
unsigned char *sha, *tha; /* s for "source", t for "target" */
struct ic_device *d;
if (dev->nd_net != &init_net)
goto drop;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
if (!pskb_may_pull(skb, sizeof(struct arphdr)))
goto drop;
/* Basic sanity checks can be done without the lock. */
rarp = (struct arphdr *)skb_transport_header(skb);
/* If this test doesn't pass, it's not IP, or we should
* ignore it anyway.
*/
if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
goto drop;
/* If it's not a RARP reply, delete it. */
if (rarp->ar_op != htons(ARPOP_RREPLY))
goto drop;
/* If it's not Ethernet, delete it. */
if (rarp->ar_pro != htons(ETH_P_IP))
goto drop;
if (!pskb_may_pull(skb, arp_hdr_len(dev)))
goto drop;
/* OK, it is all there and looks valid, process... */
rarp = (struct arphdr *)skb_transport_header(skb);
rarp_ptr = (unsigned char *) (rarp + 1);
/* One reply at a time, please. */
spin_lock(&ic_recv_lock);
/* If we already have a reply, just drop the packet */
if (ic_got_reply)
goto drop_unlock;
/* Find the ic_device that the packet arrived on */
d = ic_first_dev;
while (d && d->dev != dev)
d = d->next;
if (!d)
goto drop_unlock; /* should never happen */
/* Extract variable-width fields */
sha = rarp_ptr;
rarp_ptr += dev->addr_len;
memcpy(&sip, rarp_ptr, 4);
rarp_ptr += 4;
tha = rarp_ptr;
rarp_ptr += dev->addr_len;
memcpy(&tip, rarp_ptr, 4);
/* Discard packets which are not meant for us. */
if (memcmp(tha, dev->dev_addr, dev->addr_len))
goto drop_unlock;
/* Discard packets which are not from specified server. */
if (ic_servaddr != NONE && ic_servaddr != sip)
goto drop_unlock;
/* We have a winner! */
ic_dev = dev;
if (ic_myaddr == NONE)
ic_myaddr = tip;
ic_servaddr = sip;
ic_got_reply = IC_RARP;
drop_unlock:
/* Show's over. Nothing to see here. */
spin_unlock(&ic_recv_lock);
drop:
/* Throw the packet out. */
kfree_skb(skb);
return 0;
}
/*
* Send RARP request packet over a single interface.
*/
static void __init ic_rarp_send_if(struct ic_device *d)
{
struct net_device *dev = d->dev;
arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
dev->dev_addr, dev->dev_addr);
}
#endif
/*
* DHCP/BOOTP support.
*/
#ifdef IPCONFIG_BOOTP
struct bootp_pkt { /* BOOTP packet format */
struct iphdr iph; /* IP header */
struct udphdr udph; /* UDP header */
u8 op; /* 1=request, 2=reply */
u8 htype; /* HW address type */
u8 hlen; /* HW address length */
u8 hops; /* Used only by gateways */
__be32 xid; /* Transaction ID */
__be16 secs; /* Seconds since we started */
__be16 flags; /* Just what it says */
__be32 client_ip; /* Client's IP address if known */
__be32 your_ip; /* Assigned IP address */
__be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
__be32 relay_ip; /* IP address of BOOTP relay */
u8 hw_addr[16]; /* Client's HW address */
u8 serv_name[64]; /* Server host name */
u8 boot_file[128]; /* Name of boot file */
u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
};
/* packet ops */
#define BOOTP_REQUEST 1
#define BOOTP_REPLY 2
/* DHCP message types */
#define DHCPDISCOVER 1
#define DHCPOFFER 2
#define DHCPREQUEST 3
#define DHCPDECLINE 4
#define DHCPACK 5
#define DHCPNAK 6
#define DHCPRELEASE 7
#define DHCPINFORM 8
static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
static struct packet_type bootp_packet_type __initdata = {
.type = __constant_htons(ETH_P_IP),
.func = ic_bootp_recv,
};
/*
* Initialize DHCP/BOOTP extension fields in the request.
*/
static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
#ifdef IPCONFIG_DHCP
static void __init
ic_dhcp_init_options(u8 *options)
{
u8 mt = ((ic_servaddr == NONE)
? DHCPDISCOVER : DHCPREQUEST);
u8 *e = options;
int len;
#ifdef IPCONFIG_DEBUG
printk("DHCP: Sending message type %d\n", mt);
#endif
memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
e += 4;
*e++ = 53; /* DHCP message type */
*e++ = 1;
*e++ = mt;
if (mt == DHCPREQUEST) {
*e++ = 54; /* Server ID (IP address) */
*e++ = 4;
memcpy(e, &ic_servaddr, 4);
e += 4;
*e++ = 50; /* Requested IP address */
*e++ = 4;
memcpy(e, &ic_myaddr, 4);
e += 4;
}
/* always? */
{
static const u8 ic_req_params[] = {
1, /* Subnet mask */
3, /* Default gateway */
6, /* DNS server */
12, /* Host name */
15, /* Domain name */
17, /* Boot path */
40, /* NIS domain name */
};
*e++ = 55; /* Parameter request list */
*e++ = sizeof(ic_req_params);
memcpy(e, ic_req_params, sizeof(ic_req_params));
e += sizeof(ic_req_params);
if (*vendor_class_identifier) {
printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
vendor_class_identifier);
*e++ = 60; /* Class-identifier */
len = strlen(vendor_class_identifier);
*e++ = len;
memcpy(e, vendor_class_identifier, len);
e += len;
}
}
*e++ = 255; /* End of the list */
}
#endif /* IPCONFIG_DHCP */
static void __init ic_bootp_init_ext(u8 *e)
{
memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
e += 4;
*e++ = 1; /* Subnet mask request */
*e++ = 4;
e += 4;
*e++ = 3; /* Default gateway request */
*e++ = 4;
e += 4;
*e++ = 5; /* Name server request */
*e++ = 8;
e += 8;
*e++ = 12; /* Host name request */
*e++ = 32;
e += 32;
*e++ = 40; /* NIS Domain name request */
*e++ = 32;
e += 32;
*e++ = 17; /* Boot path */
*e++ = 40;
e += 40;
*e++ = 57; /* set extension buffer size for reply */
*e++ = 2;
*e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
*e++ = 150;
*e++ = 255; /* End of the list */
}
/*
* Initialize the DHCP/BOOTP mechanism.
*/
static inline void ic_bootp_init(void)
{
int i;
for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
ic_nameservers[i] = NONE;
dev_add_pack(&bootp_packet_type);
}
/*
* DHCP/BOOTP cleanup.
*/
static inline void ic_bootp_cleanup(void)
{
dev_remove_pack(&bootp_packet_type);
}
/*
* Send DHCP/BOOTP request to single interface.
*/
static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
{
struct net_device *dev = d->dev;
struct sk_buff *skb;
struct bootp_pkt *b;
int hh_len = LL_RESERVED_SPACE(dev);
struct iphdr *h;
/* Allocate packet */
skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL);
if (!skb)
return;
skb_reserve(skb, hh_len);
b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
memset(b, 0, sizeof(struct bootp_pkt));
/* Construct IP header */
skb_reset_network_header(skb);
h = ip_hdr(skb);
h->version = 4;
h->ihl = 5;
h->tot_len = htons(sizeof(struct bootp_pkt));
h->frag_off = htons(IP_DF);
h->ttl = 64;
h->protocol = IPPROTO_UDP;
h->daddr = htonl(INADDR_BROADCAST);
h->check = ip_fast_csum((unsigned char *) h, h->ihl);
/* Construct UDP header */
b->udph.source = htons(68);
b->udph.dest = htons(67);
b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
/* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
/* Construct DHCP/BOOTP header */
b->op = BOOTP_REQUEST;
if (dev->type < 256) /* check for false types */
b->htype = dev->type;
else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
b->htype = ARPHRD_IEEE802;
else if (dev->type == ARPHRD_FDDI)
b->htype = ARPHRD_ETHER;
else {
printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
b->htype = dev->type; /* can cause undefined behavior */
}
b->hlen = dev->addr_len;
b->your_ip = NONE;
b->server_ip = NONE;
memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
b->secs = htons(jiffies_diff / HZ);
b->xid = d->xid;
/* add DHCP options or BOOTP extensions */
#ifdef IPCONFIG_DHCP
if (ic_proto_enabled & IC_USE_DHCP)
ic_dhcp_init_options(b->exten);
else
#endif
ic_bootp_init_ext(b->exten);
/* Chain packet down the line... */
skb->dev = dev;
skb->protocol = htons(ETH_P_IP);
if (dev_hard_header(skb, dev, ntohs(skb->protocol),
dev->broadcast, dev->dev_addr, skb->len) < 0 ||
dev_queue_xmit(skb) < 0)
printk("E");
}
/*
* Copy BOOTP-supplied string if not already set.
*/
static int __init ic_bootp_string(char *dest, char *src, int len, int max)
{
if (!len)
return 0;
if (len > max-1)
len = max-1;
memcpy(dest, src, len);
dest[len] = '\0';
return 1;
}
/*
* Process BOOTP extensions.
*/
static void __init ic_do_bootp_ext(u8 *ext)
{
u8 servers;
int i;
#ifdef IPCONFIG_DEBUG
u8 *c;
printk("DHCP/BOOTP: Got extension %d:",*ext);
for (c=ext+2; c<ext+2+ext[1]; c++)
printk(" %02x", *c);
printk("\n");
#endif
switch (*ext++) {
case 1: /* Subnet mask */
if (ic_netmask == NONE)
memcpy(&ic_netmask, ext+1, 4);
break;
case 3: /* Default gateway */
if (ic_gateway == NONE)
memcpy(&ic_gateway, ext+1, 4);
break;
case 6: /* DNS server */
servers= *ext/4;
if (servers > CONF_NAMESERVERS_MAX)
servers = CONF_NAMESERVERS_MAX;
for (i = 0; i < servers; i++) {
if (ic_nameservers[i] == NONE)
memcpy(&ic_nameservers[i], ext+1+4*i, 4);
}
break;
case 12: /* Host name */
ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
ic_host_name_set = 1;
break;
case 15: /* Domain name (DNS) */
ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
break;
case 17: /* Root path */
if (!root_server_path[0])
ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
break;
case 40: /* NIS Domain name (_not_ DNS) */
ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
break;
}
}
/*
* Receive BOOTP reply.
*/
static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
{
struct bootp_pkt *b;
struct iphdr *h;
struct ic_device *d;
int len, ext_len;
if (dev->nd_net != &init_net)
goto drop;
/* Perform verifications before taking the lock. */
if (skb->pkt_type == PACKET_OTHERHOST)
goto drop;
if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
return NET_RX_DROP;
if (!pskb_may_pull(skb,
sizeof(struct iphdr) +
sizeof(struct udphdr)))
goto drop;
b = (struct bootp_pkt *)skb_network_header(skb);
h = &b->iph;
if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
goto drop;
/* Fragments are not supported */
if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
if (net_ratelimit())
printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
"reply.\n");
goto drop;
}
if (skb->len < ntohs(h->tot_len))
goto drop;
if (ip_fast_csum((char *) h, h->ihl))
goto drop;
if (b->udph.source != htons(67) || b->udph.dest != htons(68))
goto drop;
if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
goto drop;
len = ntohs(b->udph.len) - sizeof(struct udphdr);
ext_len = len - (sizeof(*b) -
sizeof(struct iphdr) -
sizeof(struct udphdr) -
sizeof(b->exten));
if (ext_len < 0)
goto drop;
/* Ok the front looks good, make sure we can get at the rest. */
if (!pskb_may_pull(skb, skb->len))
goto drop;
b = (struct bootp_pkt *)skb_network_header(skb);
h = &b->iph;
/* One reply at a time, please. */
spin_lock(&ic_recv_lock);
/* If we already have a reply, just drop the packet */
if (ic_got_reply)
goto drop_unlock;
/* Find the ic_device that the packet arrived on */
d = ic_first_dev;
while (d && d->dev != dev)
d = d->next;
if (!d)
goto drop_unlock; /* should never happen */
/* Is it a reply to our BOOTP request? */
if (b->op != BOOTP_REPLY ||
b->xid != d->xid) {
if (net_ratelimit())
printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
"op[%x] xid[%x]\n",
b->op, b->xid);
goto drop_unlock;
}
/* Parse extensions */
if (ext_len >= 4 &&
!memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
u8 *ext;
#ifdef IPCONFIG_DHCP
if (ic_proto_enabled & IC_USE_DHCP) {
__be32 server_id = NONE;
int mt = 0;
ext = &b->exten[4];
while (ext < end && *ext != 0xff) {
u8 *opt = ext++;
if (*opt == 0) /* Padding */
continue;
ext += *ext + 1;
if (ext >= end)
break;
switch (*opt) {
case 53: /* Message type */
if (opt[1])
mt = opt[2];
break;
case 54: /* Server ID (IP address) */
if (opt[1] >= 4)
memcpy(&server_id, opt + 2, 4);
break;
}
}
#ifdef IPCONFIG_DEBUG
printk("DHCP: Got message type %d\n", mt);
#endif
switch (mt) {
case DHCPOFFER:
/* While in the process of accepting one offer,
* ignore all others.
*/
if (ic_myaddr != NONE)
goto drop_unlock;
/* Let's accept that offer. */
ic_myaddr = b->your_ip;
ic_servaddr = server_id;
#ifdef IPCONFIG_DEBUG
printk("DHCP: Offered address %u.%u.%u.%u",
NIPQUAD(ic_myaddr));
printk(" by server %u.%u.%u.%u\n",
NIPQUAD(ic_servaddr));
#endif
/* The DHCP indicated server address takes
* precedence over the bootp header one if
* they are different.
*/
if ((server_id != NONE) &&
(b->server_ip != server_id))
b->server_ip = ic_servaddr;
break;
case DHCPACK:
if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
goto drop_unlock;
/* Yeah! */
break;
default:
/* Urque. Forget it*/
ic_myaddr = NONE;
ic_servaddr = NONE;
goto drop_unlock;
}
ic_dhcp_msgtype = mt;
}
#endif /* IPCONFIG_DHCP */
ext = &b->exten[4];
while (ext < end && *ext != 0xff) {
u8 *opt = ext++;
if (*opt == 0) /* Padding */
continue;
ext += *ext + 1;
if (ext < end)
ic_do_bootp_ext(opt);
}
}
/* We have a winner! */
ic_dev = dev;
ic_myaddr = b->your_ip;
ic_servaddr = b->server_ip;
if (ic_gateway == NONE && b->relay_ip)
ic_gateway = b->relay_ip;
if (ic_nameservers[0] == NONE)
ic_nameservers[0] = ic_servaddr;
ic_got_reply = IC_BOOTP;
drop_unlock:
/* Show's over. Nothing to see here. */
spin_unlock(&ic_recv_lock);
drop:
/* Throw the packet out. */
kfree_skb(skb);
return 0;
}
#endif
/*
* Dynamic IP configuration -- DHCP, BOOTP, RARP.
*/
#ifdef IPCONFIG_DYNAMIC
static int __init ic_dynamic(void)
{
int retries;
struct ic_device *d;
unsigned long start_jiffies, timeout, jiff;
int do_bootp = ic_proto_have_if & IC_BOOTP;
int do_rarp = ic_proto_have_if & IC_RARP;
/*
* If none of DHCP/BOOTP/RARP was selected, return with an error.
* This routine gets only called when some pieces of information
* are missing, and without DHCP/BOOTP/RARP we are unable to get it.
*/
if (!ic_proto_enabled) {
printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
return -1;
}
#ifdef IPCONFIG_BOOTP
if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
#endif
#ifdef IPCONFIG_RARP
if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
printk(KERN_ERR "RARP: No suitable device found.\n");
#endif
if (!ic_proto_have_if)
/* Error message already printed */
return -1;
/*
* Setup protocols
*/
#ifdef IPCONFIG_BOOTP
if (do_bootp)
ic_bootp_init();
#endif
#ifdef IPCONFIG_RARP
if (do_rarp)
ic_rarp_init();
#endif
/*
* Send requests and wait, until we get an answer. This loop
* seems to be a terrible waste of CPU time, but actually there is
* only one process running at all, so we don't need to use any
* scheduler functions.
* [Actually we could now, but the nothing else running note still
* applies.. - AC]
*/
printk(KERN_NOTICE "Sending %s%s%s requests .",
do_bootp
? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
(do_bootp && do_rarp) ? " and " : "",
do_rarp ? "RARP" : "");
start_jiffies = jiffies;
d = ic_first_dev;
retries = CONF_SEND_RETRIES;
get_random_bytes(&timeout, sizeof(timeout));
timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
for (;;) {
#ifdef IPCONFIG_BOOTP
if (do_bootp && (d->able & IC_BOOTP))
ic_bootp_send_if(d, jiffies - start_jiffies);
#endif
#ifdef IPCONFIG_RARP
if (do_rarp && (d->able & IC_RARP))
ic_rarp_send_if(d);
#endif
jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
while (time_before(jiffies, jiff) && !ic_got_reply)
schedule_timeout_uninterruptible(1);
#ifdef IPCONFIG_DHCP
/* DHCP isn't done until we get a DHCPACK. */
if ((ic_got_reply & IC_BOOTP)
&& (ic_proto_enabled & IC_USE_DHCP)
&& ic_dhcp_msgtype != DHCPACK)
{
ic_got_reply = 0;
printk(",");
continue;
}
#endif /* IPCONFIG_DHCP */
if (ic_got_reply) {
printk(" OK\n");
break;
}
if ((d = d->next))
continue;
if (! --retries) {
printk(" timed out!\n");
break;
}
d = ic_first_dev;
timeout = timeout CONF_TIMEOUT_MULT;
if (timeout > CONF_TIMEOUT_MAX)
timeout = CONF_TIMEOUT_MAX;
printk(".");
}
#ifdef IPCONFIG_BOOTP
if (do_bootp)
ic_bootp_cleanup();
#endif
#ifdef IPCONFIG_RARP
if (do_rarp)
ic_rarp_cleanup();
#endif
if (!ic_got_reply) {
ic_myaddr = NONE;
return -1;
}
printk("IP-Config: Got %s answer from %u.%u.%u.%u, ",
((ic_got_reply & IC_RARP) ? "RARP"
: (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
NIPQUAD(ic_servaddr));
printk("my address is %u.%u.%u.%u\n", NIPQUAD(ic_myaddr));
return 0;
}
#endif /* IPCONFIG_DYNAMIC */
#ifdef CONFIG_PROC_FS
static int pnp_seq_show(struct seq_file *seq, void *v)
{
int i;
if (ic_proto_used & IC_PROTO)
seq_printf(seq, "#PROTO: %s\n",
(ic_proto_used & IC_RARP) ? "RARP"
: (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
else
seq_puts(seq, "#MANUAL\n");
if (ic_domain[0])
seq_printf(seq,
"domain %s\n", ic_domain);
for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
if (ic_nameservers[i] != NONE)
seq_printf(seq,
"nameserver %u.%u.%u.%u\n",
NIPQUAD(ic_nameservers[i]));
}
if (ic_servaddr != NONE)
seq_printf(seq,
"bootserver %u.%u.%u.%u\n",
NIPQUAD(ic_servaddr));
return 0;
}
static int pnp_seq_open(struct inode *indoe, struct file *file)
{
return single_open(file, pnp_seq_show, NULL);
}
static const struct file_operations pnp_seq_fops = {
.owner = THIS_MODULE,
.open = pnp_seq_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
#endif /* CONFIG_PROC_FS */
/*
* Extract IP address from the parameter string if needed. Note that we
* need to have root_server_addr set _before_ IPConfig gets called as it
* can override it.
*/
__be32 __init root_nfs_parse_addr(char *name)
{
__be32 addr;
int octets = 0;
char *cp, *cq;
cp = cq = name;
while (octets < 4) {
while (*cp >= '0' && *cp <= '9')
cp++;
if (cp == cq || cp - cq > 3)
break;
if (*cp == '.' || octets == 3)
octets++;
if (octets < 4)
cp++;
cq = cp;
}
if (octets == 4 && (*cp == ':' || *cp == '\0')) {
if (*cp == ':')
*cp++ = '\0';
addr = in_aton(name);
memmove(name, cp, strlen(cp) + 1);
} else
addr = NONE;
return addr;
}
/*
* IP Autoconfig dispatcher.
*/
static int __init ip_auto_config(void)
{
__be32 addr;
#ifdef CONFIG_PROC_FS
proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
#endif /* CONFIG_PROC_FS */
if (!ic_enable)
return 0;
DBG(("IP-Config: Entered.\n"));
#ifdef IPCONFIG_DYNAMIC
try_try_again:
#endif
/* Give hardware a chance to settle */
msleep(CONF_PRE_OPEN);
/* Setup all network devices */
if (ic_open_devs() < 0)
return -1;
/* Give drivers a chance to settle */
ssleep(CONF_POST_OPEN);
/*
* If the config information is insufficient (e.g., our IP address or
* IP address of the boot server is missing or we have multiple network
* interfaces and no default was set), use BOOTP or RARP to get the
* missing values.
*/
if (ic_myaddr == NONE ||
#ifdef CONFIG_ROOT_NFS
(root_server_addr == NONE
&& ic_servaddr == NONE
&& ROOT_DEV == Root_NFS) ||
#endif
ic_first_dev->next) {
#ifdef IPCONFIG_DYNAMIC
int retries = CONF_OPEN_RETRIES;
if (ic_dynamic() < 0) {
ic_close_devs();
/*
* I don't know why, but sometimes the
* eepro100 driver (at least) gets upset and
* doesn't work the first time it's opened.
* But then if you close it and reopen it, it
* works just fine. So we need to try that at
* least once before giving up.
*
* Also, if the root will be NFS-mounted, we
* have nowhere to go if DHCP fails. So we
* just have to keep trying forever.
*
* -- Chip
*/
#ifdef CONFIG_ROOT_NFS
if (ROOT_DEV == Root_NFS) {
printk(KERN_ERR
"IP-Config: Retrying forever (NFS root)...\n");
goto try_try_again;
}
#endif
if (--retries) {
printk(KERN_ERR
"IP-Config: Reopening network devices...\n");
goto try_try_again;
}
/* Oh, well. At least we tried. */
printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
return -1;
}
#else /* !DYNAMIC */
printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
ic_close_devs();
return -1;
#endif /* IPCONFIG_DYNAMIC */
} else {
/* Device selected manually or only one device -> use it */
ic_dev = ic_first_dev->dev;
}
addr = root_nfs_parse_addr(root_server_path);
if (root_server_addr == NONE)
root_server_addr = addr;
/*
* Use defaults whereever applicable.
*/
if (ic_defaults() < 0)
return -1;
/*
* Close all network devices except the device we've
* autoconfigured and set up routes.
*/
ic_close_devs();
if (ic_setup_if() < 0 || ic_setup_routes() < 0)
return -1;
/*
* Record which protocol was actually used.
*/
#ifdef IPCONFIG_DYNAMIC
ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
#endif
#ifndef IPCONFIG_SILENT
/*
* Clue in the operator.
*/
printk("IP-Config: Complete:");
printk("\n device=%s", ic_dev->name);
printk(", addr=%u.%u.%u.%u", NIPQUAD(ic_myaddr));
printk(", mask=%u.%u.%u.%u", NIPQUAD(ic_netmask));
printk(", gw=%u.%u.%u.%u", NIPQUAD(ic_gateway));
printk(",\n host=%s, domain=%s, nis-domain=%s",
utsname()->nodename, ic_domain, utsname()->domainname);
printk(",\n bootserver=%u.%u.%u.%u", NIPQUAD(ic_servaddr));
printk(", rootserver=%u.%u.%u.%u", NIPQUAD(root_server_addr));
printk(", rootpath=%s", root_server_path);
printk("\n");
#endif /* !SILENT */
return 0;
}
late_initcall(ip_auto_config);
/*
* Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
* command line parameter. See Documentation/nfsroot.txt.
*/
static int __init ic_proto_name(char *name)
{
if (!strcmp(name, "on") || !strcmp(name, "any")) {
return 1;
}
if (!strcmp(name, "off") || !strcmp(name, "none")) {
return 0;
}
#ifdef CONFIG_IP_PNP_DHCP
else if (!strcmp(name, "dhcp")) {
ic_proto_enabled &= ~IC_RARP;
return 1;
}
#endif
#ifdef CONFIG_IP_PNP_BOOTP
else if (!strcmp(name, "bootp")) {
ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
return 1;
}
#endif
#ifdef CONFIG_IP_PNP_RARP
else if (!strcmp(name, "rarp")) {
ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
return 1;
}
#endif
#ifdef IPCONFIG_DYNAMIC
else if (!strcmp(name, "both")) {
ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
return 1;
}
#endif
return 0;
}
static int __init ip_auto_config_setup(char *addrs)
{
char *cp, *ip, *dp;
int num = 0;
ic_set_manually = 1;
ic_enable = 1;
/*
* If any dhcp, bootp etc options are set, leave autoconfig on
* and skip the below static IP processing.
*/
if (ic_proto_name(addrs))
return 1;
/* If no static IP is given, turn off autoconfig and bail. */
if (*addrs == 0 ||
strcmp(addrs, "off") == 0 ||
strcmp(addrs, "none") == 0) {
ic_enable = 0;
return 1;
}
/* Parse string for static IP assignment. */
ip = addrs;
while (ip && *ip) {
if ((cp = strchr(ip, ':')))
*cp++ = '\0';
if (strlen(ip) > 0) {
DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
switch (num) {
case 0:
if ((ic_myaddr = in_aton(ip)) == INADDR_ANY)
ic_myaddr = NONE;
break;
case 1:
if ((ic_servaddr = in_aton(ip)) == INADDR_ANY)
ic_servaddr = NONE;
break;
case 2:
if ((ic_gateway = in_aton(ip)) == INADDR_ANY)
ic_gateway = NONE;
break;
case 3:
if ((ic_netmask = in_aton(ip)) == INADDR_ANY)
ic_netmask = NONE;
break;
case 4:
if ((dp = strchr(ip, '.'))) {
*dp++ = '\0';
strlcpy(utsname()->domainname, dp,
sizeof(utsname()->domainname));
}
strlcpy(utsname()->nodename, ip,
sizeof(utsname()->nodename));
ic_host_name_set = 1;
break;
case 5:
strlcpy(user_dev_name, ip, sizeof(user_dev_name));
break;
case 6:
if (ic_proto_name(ip) == 0 &&
ic_myaddr == NONE) {
ic_enable = 0;
}
break;
}
}
ip = cp;
num++;
}
return 1;
}
static int __init nfsaddrs_config_setup(char *addrs)
{
return ip_auto_config_setup(addrs);
}
static int __init vendor_class_identifier_setup(char *addrs)
{
if (strlcpy(vendor_class_identifier, addrs,
sizeof(vendor_class_identifier))
>= sizeof(vendor_class_identifier))
printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
vendor_class_identifier);
return 1;
}
__setup("ip=", ip_auto_config_setup);
__setup("nfsaddrs=", nfsaddrs_config_setup);
__setup("dhcpclass=", vendor_class_identifier_setup);
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