cregit-Linux how code gets into the kernel

Release 4.14 net/ipv4/ipconfig.c

Directory: net/ipv4
// SPDX-License-Identifier: GPL-2.0
/*
 *  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 <linux/slab.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/arp.h>
#include <net/dsa.h>
#include <net/ip.h>
#include <net/ipconfig.h>
#include <net/route.h>

#include <linux/uaccess.h>
#include <net/checksum.h>
#include <asm/processor.h>

#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_POST_OPEN		10	
/* After opening: 10 msecs */

#define CONF_CARRIER_TIMEOUT	120000	
/* Wait for carrier timeout */

/* 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_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 cpu_to_be32(INADDR_NONE)

#define ANY cpu_to_be32(INADDR_ANY)

/*
 * 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;		
/* 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;	
/* 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 */

#ifdef IPCONFIG_DYNAMIC

static __be32 ic_addrservaddr = NONE;	
/* IP Address of the IP addresses'server */
#endif


__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;

#if defined(CONFIG_IP_PNP_DHCP)

static char dhcp_client_identifier[253] __initdata;
#endif

/* Persistent data: */

#ifdef IPCONFIG_DYNAMIC

static int ic_proto_used;			
/* Protocol used, if any */
#else

#define ic_proto_used 0
#endif

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;

/* MTU for boot device */

static int ic_dev_mtu __initdata;

#ifdef IPCONFIG_DYNAMIC
static DEFINE_SPINLOCK(ic_recv_lock);

static volatile int ic_got_reply __initdata;    
/* Proto(s) that replied */
#endif
#ifdef IPCONFIG_DHCP

static int ic_dhcp_msgtype __initdata;	
/* 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;	
/* List of open device */

static struct ic_device *ic_dev __initdata;		
/* Selected device */




static bool __init ic_is_init_dev(struct net_device *dev)
{
	if (dev->flags & IFF_LOOPBACK)
		return false;
	return 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));
}


Contributors
PersonTokensPropCommitsCommitProp
David S. Miller6284.93%150.00%


Micha Nelissen1115.07%150.00%


Total73100.00%2100.00%






static int __init ic_open_devs(void)
{
	struct ic_device *d, **last;
	struct net_device *dev;
	unsigned short oflags;
	unsigned long start, next_msg;

	last = &ic_first_dev;
	rtnl_lock();

	/* bring loopback and DSA master network devices up first */
	for_each_netdev(&init_net, dev) {
		if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
			continue;
		if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
			pr_err("IP-Config: Failed to open %s\n", dev->name);
	}

	for_each_netdev(&init_net, dev) {
		if (ic_is_init_dev(dev)) {
			int able = 0;
			if (dev->mtu >= 364)
				able |= IC_BOOTP;
			else
				pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
					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) {
				pr_err("IP-Config: Failed to open %s\n",
				       dev->name);
				continue;
			}
			if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
				rtnl_unlock();
				return -ENOMEM;
			}
			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;
			pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
				 dev->name, able, d->xid);
		}
	}

	/* no point in waiting if we could not bring up at least one device */
	if (!ic_first_dev)
		goto have_carrier;

	/* wait for a carrier on at least one device */
	start = jiffies;
	next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
	while (time_before(jiffies, start +
			   msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
		int wait, elapsed;

		for_each_netdev(&init_net, dev)
			if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
				goto have_carrier;

		msleep(1);

		if (time_before(jiffies, next_msg))
			continue;

		elapsed = jiffies_to_msecs(jiffies - start);
		wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
		pr_info("Waiting up to %d more seconds for network.\n", wait);
		next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
	}
have_carrier:
	rtnl_unlock();

	*last = NULL;

	if (!ic_first_dev) {
		if (user_dev_name[0])
			pr_err("IP-Config: Device `%s' not found\n",
			       user_dev_name);
		else
			pr_err("IP-Config: No network devices available\n");
		return -ENODEV;
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)22849.03%521.74%


Paul Gortmaker6213.33%14.35%


Micha Nelissen4910.54%14.35%


Linus Torvalds337.10%28.70%


Eric W. Biedermann255.38%28.70%


Hideaki Yoshifuji / 吉藤英明183.87%14.35%


Gerlando Falauto91.94%14.35%


Joe Perches71.51%14.35%


Florian Fainelli71.51%14.35%


Bastian Stender51.08%14.35%


François-Xavier Le Bail51.08%14.35%


Himangi Saraogi51.08%14.35%


Pavel Emelyanov40.86%14.35%


Stephen Hemminger30.65%14.35%


David S. Miller20.43%14.35%


Daniel Lezcano20.43%14.35%


Al Viro10.22%14.35%


Total465100.00%23100.00%






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 (d != ic_dev && !netdev_uses_dsa(dev)) {
			pr_debug("IP-Config: Downing %s\n", dev->name);
			dev_change_flags(dev, d->flags);
		}
		kfree(d);
	}
	rtnl_unlock();
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)8087.91%555.56%


Florian Fainelli66.59%111.11%


Stephen Hemminger22.20%111.11%


Bastian Stender22.20%111.11%


Mark Rutland11.10%111.11%


Total91100.00%9100.00%



/*
 *      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;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)3694.74%150.00%


Al Viro25.26%150.00%


Total38100.00%2100.00%






static int __init ic_devinet_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;
}


Contributors
PersonTokensPropCommitsCommitProp
Chris Friesen57100.00%1100.00%


Total57100.00%1100.00%






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 = dev_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
	set_fs(oldfs);
	return res;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4782.46%240.00%


Stephen Hemminger610.53%120.00%


Denis V. Lunev35.26%120.00%


Chris Friesen11.75%120.00%


Total57100.00%5100.00%






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;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4885.71%250.00%


Stephen Hemminger58.93%125.00%


Denis V. Lunev35.36%125.00%


Total56100.00%4100.00%



/*
 *      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->dev->name);
	set_sockaddr(sin, ic_myaddr, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFADDR, &ir)) < 0) {
		pr_err("IP-Config: Unable to set interface address (%d)\n",
		       err);
		return -1;
	}
	set_sockaddr(sin, ic_netmask, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
		pr_err("IP-Config: Unable to set interface netmask (%d)\n",
		       err);
		return -1;
	}
	set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
	if ((err = ic_devinet_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
		pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
		       err);
		return -1;
	}
	/* Handle the case where we need non-standard MTU on the boot link (a network
         * using jumbo frames, for instance).  If we can't set the mtu, don't error
         * out, we'll try to muddle along.
         */
	if (ic_dev_mtu != 0) {
		strcpy(ir.ifr_name, ic_dev->dev->name);
		ir.ifr_mtu = ic_dev_mtu;
		if ((err = ic_dev_ioctl(SIOCSIFMTU, &ir)) < 0)
			pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
			       ic_dev_mtu, err);
	}
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)16972.53%240.00%


Chris Friesen5222.32%120.00%


Joe Perches83.43%120.00%


Uwe Kleine-König41.72%120.00%


Total233100.00%5100.00%






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) {
			pr_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) {
			pr_err("IP-Config: Cannot add default route (%d)\n",
			       err);
			return -1;
		}
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)14596.67%250.00%


Joe Perches42.67%125.00%


Al Viro10.67%125.00%


Total150100.00%4100.00%



/*
 *      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, "%pI4", &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 {
			pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
			       &ic_myaddr);
			return -1;
		}
		pr_notice("IP-Config: Guessing netmask %pI4\n",
			  &ic_netmask);
	}

	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)10785.60%436.36%


Harvey Harrison64.80%19.09%


Hideaki Yoshifuji / 吉藤英明32.40%19.09%


Serge E. Hallyn32.40%19.09%


Al Viro21.60%19.09%


Linus Torvalds21.60%19.09%


Joe Perches10.80%19.09%


Bastian Stender10.80%19.09%


Total125100.00%11100.00%



/*
 *      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 =	cpu_to_be16(ETH_P_RARP),
	.func =	ic_rarp_recv,
};




static inline void __init ic_rarp_init(void)
{
	dev_add_pack(&rarp_packet_type);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1593.75%266.67%


Sam Ravnborg16.25%133.33%


Total16100.00%3100.00%






static inline void __init ic_rarp_cleanup(void)
{
	dev_remove_pack(&rarp_packet_type);
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)1593.75%266.67%


Sam Ravnborg16.25%133.33%


Total16100.00%3100.00%



/*
 *  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 *tha;		/* t for "target" */
	struct ic_device *d;

	if (!net_eq(dev_net(dev), &init_net))
		goto drop;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (!skb)
		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 */
	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 = d;
	if (ic_myaddr == NONE)
		ic_myaddr = tip;
	ic_servaddr = sip;
	ic_addrservaddr = 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;
}



Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)19551.32%420.00%


David S. Miller12532.89%315.00%


Linus Torvalds215.53%210.00%


Hideaki Yoshifuji / 吉藤英明102.63%315.00%


Eric W. Biedermann71.84%15.00%


Arnaldo Carvalho de Melo61.58%15.00%


Ian Morris51.32%15.00%


Philippe De Muyter41.05%15.00%


Al Viro30.79%15.00%


Pavel Emelyanov20.53%15.00%


Fabian Frederick10.26%15.00%


Uwe Kleine-König10.26%15.00%


Total380100.00%20100.00%



/*
 *  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);
}

Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds (pre-git)4295.45%375.00%


Linus Torvalds24.55%125.00%


Total44100.00%4100.00%



#endif

/*
 *  Predefine Nameservers
 */



static inline void __init ic_nameservers_predef(void)
{
	int i;

	for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
		ic_nameservers[i] = NONE;
}


Contributors
PersonTokensPropCommitsCommitProp
Andy Shevchenko33100.00%1100.00%


Total33100.00%1100.00%



/*
 *      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 =	cpu_to_be16(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, struct ic_device *d)
{
	u8 mt = ((ic_servaddr == NONE)
		 ? DHCPDISCOVER : DHCPREQUEST);
	u8 *e = options;
	int len;

	pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);

	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 */
			26,	/* MTU */
			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 (ic_host_name_set) {
			*e++ = 12;	/* host-name */
			len = strlen(utsname()->nodename);
			*e++ = len;
			memcpy(e, utsname()->nodename, len);
			e += len;
		}
		if (*vendor_class_identifier) {
			pr_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;
		}
		len = strlen(dhcp_client_identifier + 1);
		/* the minimum length of identifier is 2, include 1 byte type,
                 * and can not be larger than the length of options
                 */
		if (len >= 1 && len < 312 - (e - options) - 1) {
			*e++ = 61;
			*e++ = len + 1;
			memcpy(e, dhcp_client_identifier, len + 1);
			e += len + 1;
		}
	}

	*e++ = 255;	/* End of the list */
}


Contributors
PersonTokensPropCommitsCommitProp
Linus Torvalds17947.23%19.09%


Li RongQing6116.09%19.09%


Rainer Jochem4912.93%19.09%


Fengguang Wu4511.87%19.09%


Linus Torvalds (pre-git)277.12%218.18%


Uwe Kleine-König123.17%19.09%


Chris Friesen30.79%19.09%


Joe Perches10.26%19.09%


Al Viro10.26%19.09%


Bastian Stender10.26%19.09%


Total379100.00%11100.00%



#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;