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ipconfig.c
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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/config.h>
#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/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 <net/arp.h>
#include <net/ip.h>
#include <net/ipconfig.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 */
/*
* 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? */
u32 ic_myaddr = INADDR_NONE; /* My IP address */
static u32 ic_netmask = INADDR_NONE; /* Netmask for local subnet */
u32 ic_gateway = INADDR_NONE; /* Gateway IP address */
u32 ic_servaddr = INADDR_NONE; /* Boot server IP address */
u32 root_server_addr = INADDR_NONE; /* Address of NFS server */
u8 root_server_path[256] = { 0, }; /* Path to mount as root */
/* Persistent data: */
static int ic_proto_used; /* Protocol used, if any */
static u32 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;
u32 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_shlock();
/* bring loopback device up first */
if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0)
printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name);
for (dev = dev_base; dev; dev = dev->next) {
if (dev == &loopback_dev)
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_shunlock();
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(u32));
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_shunlock();
*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_shlock();
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_shunlock();
}
/*
* Interface to various network functions.
*/
static inline void
set_sockaddr(struct sockaddr_in *sin, u32 addr, u16 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(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(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 != INADDR_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(system_utsname.nodename, "%u.%u.%u.%u", NIPQUAD(ic_myaddr));
if (root_server_addr == INADDR_NONE)
root_server_addr = ic_servaddr;
if (ic_netmask == INADDR_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);
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 arphdr *rarp;
unsigned char *rarp_ptr;
unsigned long sip, tip;
unsigned char *sha, *tha; /* s for "source", t for "target" */
struct ic_device *d;
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->h.raw;
/* 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,
sizeof(struct arphdr) +
(2 * dev->addr_len) +
(2 * 4)))
goto drop;
/* OK, it is all there and looks valid, process... */
rarp = (struct arphdr *)skb->h.raw;
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 != INADDR_NONE && ic_servaddr != sip)
goto drop_unlock;
/* We have a winner! */
ic_dev = dev;
if (ic_myaddr == INADDR_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 */
u32 xid; /* Transaction ID */
u16 secs; /* Seconds since we started */
u16 flags; /* Just what it says */
u32 client_ip; /* Client's IP address if known */
u32 your_ip; /* Assigned IP address */
u32 server_ip; /* (Next, e.g. NFS) Server's IP address */
u32 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);
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 == INADDR_NONE)
? DHCPDISCOVER : DHCPREQUEST);
u8 *e = options;
#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);
}
*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] = INADDR_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->nh.iph = h = &b->iph;
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 = 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 = INADDR_NONE;
b->server_ip = INADDR_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 &&
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 == INADDR_NONE)
memcpy(&ic_netmask, ext+1, 4);
break;
case 3: /* Default gateway */
if (ic_gateway == INADDR_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] == INADDR_NONE)
memcpy(&ic_nameservers[i], ext+1+4*i, 4);
}
break;
case 12: /* Host name */
ic_bootp_string(system_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(system_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 bootp_pkt *b;
struct iphdr *h;
struct ic_device *d;
int len, ext_len;
/* 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->nh.iph;
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->nh.iph;
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) {
u32 server_id = INADDR_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 != INADDR_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 != INADDR_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 = INADDR_NONE;
ic_servaddr = INADDR_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);
}
}