2 * $Id: ipconfig.c,v 1.46 2002/02/01 22:01:04 davem Exp $
4 * Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
5 * user-supplied information to configure own IP address and routes.
7 * Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
9 * Derived from network configuration code in fs/nfs/nfsroot.c,
10 * originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
12 * BOOTP rewritten to construct and analyse packets itself instead
13 * of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
14 * -- MJ, December 1998
16 * Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
17 * initialization scheme.
18 * - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
20 * DHCP support added. To users this looks like a whole separate
21 * protocol, but we know it's just a bag on the side of BOOTP.
22 * -- Chip Salzenberg <chip@valinux.com>, May 2000
24 * Ported DHCP support from 2.2.16 to 2.4.0-test4
25 * -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
27 * Merged changes from 2.2.19 into 2.4.3
28 * -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
30 * Multiple Nameservers in /proc/net/pnp
31 * -- Josef Siemes <jsiemes@web.de>, Aug 2002
34 #include <linux/types.h>
35 #include <linux/string.h>
36 #include <linux/kernel.h>
37 #include <linux/jiffies.h>
38 #include <linux/random.h>
39 #include <linux/init.h>
40 #include <linux/utsname.h>
43 #include <linux/inet.h>
44 #include <linux/inetdevice.h>
45 #include <linux/netdevice.h>
46 #include <linux/if_arp.h>
47 #include <linux/skbuff.h>
49 #include <linux/socket.h>
50 #include <linux/route.h>
51 #include <linux/udp.h>
52 #include <linux/proc_fs.h>
53 #include <linux/seq_file.h>
54 #include <linux/major.h>
55 #include <linux/root_dev.h>
56 #include <linux/delay.h>
57 #include <linux/nfs_fs.h>
58 #include <net/net_namespace.h>
61 #include <net/ipconfig.h>
62 #include <net/route.h>
64 #include <asm/uaccess.h>
65 #include <net/checksum.h>
66 #include <asm/processor.h>
68 /* Define this to allow debugging output */
72 #define DBG(x) printk x
74 #define DBG(x) do { } while(0)
77 #if defined(CONFIG_IP_PNP_DHCP)
80 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
81 #define IPCONFIG_BOOTP
83 #if defined(CONFIG_IP_PNP_RARP)
86 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
87 #define IPCONFIG_DYNAMIC
90 /* Define the friendly delay before and after opening net devices */
91 #define CONF_PRE_OPEN 500 /* Before opening: 1/2 second */
92 #define CONF_POST_OPEN 1 /* After opening: 1 second */
94 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
95 #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
96 #define CONF_SEND_RETRIES 6 /* Send six requests per open */
97 #define CONF_INTER_TIMEOUT (HZ/2) /* Inter-device timeout: 1/2 second */
98 #define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */
99 #define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */
100 #define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */
101 #define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */
102 #define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
103 - '3' from resolv.h */
105 #define NONE __constant_htonl(INADDR_NONE)
106 #define ANY __constant_htonl(INADDR_ANY)
109 * Public IP configuration
112 /* This is used by platforms which might be able to set the ipconfig
113 * variables using firmware environment vars. If this is set, it will
114 * ignore such firmware variables.
116 int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
118 static int ic_enable __initdata = 0; /* IP config enabled? */
120 /* Protocol choice */
121 int ic_proto_enabled __initdata = 0
122 #ifdef IPCONFIG_BOOTP
125 #ifdef CONFIG_IP_PNP_DHCP
133 static int ic_host_name_set __initdata = 0; /* Host name set by us? */
135 __be32 ic_myaddr = NONE; /* My IP address */
136 static __be32 ic_netmask = NONE; /* Netmask for local subnet */
137 __be32 ic_gateway = NONE; /* Gateway IP address */
139 __be32 ic_servaddr = NONE; /* Boot server IP address */
141 __be32 root_server_addr = NONE; /* Address of NFS server */
142 u8 root_server_path[256] = { 0, }; /* Path to mount as root */
144 /* vendor class identifier */
145 static char vendor_class_identifier[253] __initdata;
147 /* Persistent data: */
149 static int ic_proto_used; /* Protocol used, if any */
150 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
151 static u8 ic_domain[64]; /* DNS (not NIS) domain name */
157 /* Name of user-selected boot device */
158 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
160 /* Protocols supported by available interfaces */
161 static int ic_proto_have_if __initdata = 0;
163 #ifdef IPCONFIG_DYNAMIC
164 static DEFINE_SPINLOCK(ic_recv_lock);
165 static volatile int ic_got_reply __initdata = 0; /* Proto(s) that replied */
168 static int ic_dhcp_msgtype __initdata = 0; /* DHCP msg type received */
177 struct ic_device *next;
178 struct net_device *dev;
179 unsigned short flags;
184 static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */
185 static struct net_device *ic_dev __initdata = NULL; /* Selected device */
187 static int __init ic_open_devs(void)
189 struct ic_device *d, **last;
190 struct net_device *dev;
191 unsigned short oflags;
193 last = &ic_first_dev;
196 /* bring loopback device up first */
197 for_each_netdev(&init_net, dev) {
198 if (!(dev->flags & IFF_LOOPBACK))
200 if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
201 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
204 for_each_netdev(&init_net, dev) {
205 if (dev->flags & IFF_LOOPBACK)
207 if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
208 (!(dev->flags & IFF_LOOPBACK) &&
209 (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
210 strncmp(dev->name, "dummy", 5))) {
215 printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu);
216 if (!(dev->flags & IFF_NOARP))
218 able &= ic_proto_enabled;
219 if (ic_proto_enabled && !able)
222 if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
223 printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name);
226 if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
236 get_random_bytes(&d->xid, sizeof(__be32));
239 ic_proto_have_if |= able;
240 DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n",
241 dev->name, able, d->xid));
249 if (user_dev_name[0])
250 printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name);
252 printk(KERN_ERR "IP-Config: No network devices available.\n");
258 static void __init ic_close_devs(void)
260 struct ic_device *d, *next;
261 struct net_device *dev;
269 DBG(("IP-Config: Downing %s\n", dev->name));
270 dev_change_flags(dev, d->flags);
278 * Interface to various network functions.
282 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
284 sin->sin_family = AF_INET;
285 sin->sin_addr.s_addr = addr;
286 sin->sin_port = port;
289 static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg)
293 mm_segment_t oldfs = get_fs();
295 res = devinet_ioctl(&init_net, cmd, (struct ifreq __user *) arg);
300 static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg)
304 mm_segment_t oldfs = get_fs();
306 res = ip_rt_ioctl(&init_net, cmd, (void __user *) arg);
312 * Set up interface addresses and routes.
315 static int __init ic_setup_if(void)
318 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
321 memset(&ir, 0, sizeof(ir));
322 strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name);
323 set_sockaddr(sin, ic_myaddr, 0);
324 if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) {
325 printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err);
328 set_sockaddr(sin, ic_netmask, 0);
329 if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) {
330 printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err);
333 set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
334 if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) {
335 printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err);
341 static int __init ic_setup_routes(void)
343 /* No need to setup device routes, only the default route... */
345 if (ic_gateway != NONE) {
349 memset(&rm, 0, sizeof(rm));
350 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
351 printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n");
354 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
355 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
356 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
357 rm.rt_flags = RTF_UP | RTF_GATEWAY;
358 if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) {
359 printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err);
368 * Fill in default values for all missing parameters.
371 static int __init ic_defaults(void)
374 * At this point we have no userspace running so need not
375 * claim locks on system_utsname
378 if (!ic_host_name_set)
379 sprintf(init_utsname()->nodename, NIPQUAD_FMT, NIPQUAD(ic_myaddr));
381 if (root_server_addr == NONE)
382 root_server_addr = ic_servaddr;
384 if (ic_netmask == NONE) {
385 if (IN_CLASSA(ntohl(ic_myaddr)))
386 ic_netmask = htonl(IN_CLASSA_NET);
387 else if (IN_CLASSB(ntohl(ic_myaddr)))
388 ic_netmask = htonl(IN_CLASSB_NET);
389 else if (IN_CLASSC(ntohl(ic_myaddr)))
390 ic_netmask = htonl(IN_CLASSC_NET);
392 printk(KERN_ERR "IP-Config: Unable to guess netmask for address " NIPQUAD_FMT "\n",
396 printk("IP-Config: Guessing netmask " NIPQUAD_FMT "\n", NIPQUAD(ic_netmask));
408 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
410 static struct packet_type rarp_packet_type __initdata = {
411 .type = __constant_htons(ETH_P_RARP),
412 .func = ic_rarp_recv,
415 static inline void __init ic_rarp_init(void)
417 dev_add_pack(&rarp_packet_type);
420 static inline void __init ic_rarp_cleanup(void)
422 dev_remove_pack(&rarp_packet_type);
426 * Process received RARP packet.
429 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
432 unsigned char *rarp_ptr;
434 unsigned char *sha, *tha; /* s for "source", t for "target" */
437 if (dev_net(dev) != &init_net)
440 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
443 if (!pskb_may_pull(skb, sizeof(struct arphdr)))
446 /* Basic sanity checks can be done without the lock. */
447 rarp = (struct arphdr *)skb_transport_header(skb);
449 /* If this test doesn't pass, it's not IP, or we should
452 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
455 /* If it's not a RARP reply, delete it. */
456 if (rarp->ar_op != htons(ARPOP_RREPLY))
459 /* If it's not Ethernet, delete it. */
460 if (rarp->ar_pro != htons(ETH_P_IP))
463 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
466 /* OK, it is all there and looks valid, process... */
467 rarp = (struct arphdr *)skb_transport_header(skb);
468 rarp_ptr = (unsigned char *) (rarp + 1);
470 /* One reply at a time, please. */
471 spin_lock(&ic_recv_lock);
473 /* If we already have a reply, just drop the packet */
477 /* Find the ic_device that the packet arrived on */
479 while (d && d->dev != dev)
482 goto drop_unlock; /* should never happen */
484 /* Extract variable-width fields */
486 rarp_ptr += dev->addr_len;
487 memcpy(&sip, rarp_ptr, 4);
490 rarp_ptr += dev->addr_len;
491 memcpy(&tip, rarp_ptr, 4);
493 /* Discard packets which are not meant for us. */
494 if (memcmp(tha, dev->dev_addr, dev->addr_len))
497 /* Discard packets which are not from specified server. */
498 if (ic_servaddr != NONE && ic_servaddr != sip)
501 /* We have a winner! */
503 if (ic_myaddr == NONE)
506 ic_got_reply = IC_RARP;
509 /* Show's over. Nothing to see here. */
510 spin_unlock(&ic_recv_lock);
513 /* Throw the packet out. */
520 * Send RARP request packet over a single interface.
522 static void __init ic_rarp_send_if(struct ic_device *d)
524 struct net_device *dev = d->dev;
525 arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
526 dev->dev_addr, dev->dev_addr);
531 * DHCP/BOOTP support.
534 #ifdef IPCONFIG_BOOTP
536 struct bootp_pkt { /* BOOTP packet format */
537 struct iphdr iph; /* IP header */
538 struct udphdr udph; /* UDP header */
539 u8 op; /* 1=request, 2=reply */
540 u8 htype; /* HW address type */
541 u8 hlen; /* HW address length */
542 u8 hops; /* Used only by gateways */
543 __be32 xid; /* Transaction ID */
544 __be16 secs; /* Seconds since we started */
545 __be16 flags; /* Just what it says */
546 __be32 client_ip; /* Client's IP address if known */
547 __be32 your_ip; /* Assigned IP address */
548 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
549 __be32 relay_ip; /* IP address of BOOTP relay */
550 u8 hw_addr[16]; /* Client's HW address */
551 u8 serv_name[64]; /* Server host name */
552 u8 boot_file[128]; /* Name of boot file */
553 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
557 #define BOOTP_REQUEST 1
558 #define BOOTP_REPLY 2
560 /* DHCP message types */
561 #define DHCPDISCOVER 1
563 #define DHCPREQUEST 3
564 #define DHCPDECLINE 4
567 #define DHCPRELEASE 7
570 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
572 static struct packet_type bootp_packet_type __initdata = {
573 .type = __constant_htons(ETH_P_IP),
574 .func = ic_bootp_recv,
579 * Initialize DHCP/BOOTP extension fields in the request.
582 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
587 ic_dhcp_init_options(u8 *options)
589 u8 mt = ((ic_servaddr == NONE)
590 ? DHCPDISCOVER : DHCPREQUEST);
594 #ifdef IPCONFIG_DEBUG
595 printk("DHCP: Sending message type %d\n", mt);
598 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
601 *e++ = 53; /* DHCP message type */
605 if (mt == DHCPREQUEST) {
606 *e++ = 54; /* Server ID (IP address) */
608 memcpy(e, &ic_servaddr, 4);
611 *e++ = 50; /* Requested IP address */
613 memcpy(e, &ic_myaddr, 4);
619 static const u8 ic_req_params[] = {
621 3, /* Default gateway */
624 15, /* Domain name */
626 40, /* NIS domain name */
629 *e++ = 55; /* Parameter request list */
630 *e++ = sizeof(ic_req_params);
631 memcpy(e, ic_req_params, sizeof(ic_req_params));
632 e += sizeof(ic_req_params);
634 if (*vendor_class_identifier) {
635 printk(KERN_INFO "DHCP: sending class identifier \"%s\"\n",
636 vendor_class_identifier);
637 *e++ = 60; /* Class-identifier */
638 len = strlen(vendor_class_identifier);
640 memcpy(e, vendor_class_identifier, len);
645 *e++ = 255; /* End of the list */
648 #endif /* IPCONFIG_DHCP */
650 static void __init ic_bootp_init_ext(u8 *e)
652 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
654 *e++ = 1; /* Subnet mask request */
657 *e++ = 3; /* Default gateway request */
660 *e++ = 5; /* Name server request */
663 *e++ = 12; /* Host name request */
666 *e++ = 40; /* NIS Domain name request */
669 *e++ = 17; /* Boot path */
673 *e++ = 57; /* set extension buffer size for reply */
675 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
678 *e++ = 255; /* End of the list */
683 * Initialize the DHCP/BOOTP mechanism.
685 static inline void __init ic_bootp_init(void)
689 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
690 ic_nameservers[i] = NONE;
692 dev_add_pack(&bootp_packet_type);
697 * DHCP/BOOTP cleanup.
699 static inline void __init ic_bootp_cleanup(void)
701 dev_remove_pack(&bootp_packet_type);
706 * Send DHCP/BOOTP request to single interface.
708 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
710 struct net_device *dev = d->dev;
715 /* Allocate packet */
716 skb = alloc_skb(sizeof(struct bootp_pkt) + LL_ALLOCATED_SPACE(dev) + 15,
720 skb_reserve(skb, LL_RESERVED_SPACE(dev));
721 b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt));
722 memset(b, 0, sizeof(struct bootp_pkt));
724 /* Construct IP header */
725 skb_reset_network_header(skb);
729 h->tot_len = htons(sizeof(struct bootp_pkt));
730 h->frag_off = htons(IP_DF);
732 h->protocol = IPPROTO_UDP;
733 h->daddr = htonl(INADDR_BROADCAST);
734 h->check = ip_fast_csum((unsigned char *) h, h->ihl);
736 /* Construct UDP header */
737 b->udph.source = htons(68);
738 b->udph.dest = htons(67);
739 b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
740 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
742 /* Construct DHCP/BOOTP header */
743 b->op = BOOTP_REQUEST;
744 if (dev->type < 256) /* check for false types */
745 b->htype = dev->type;
746 else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */
747 b->htype = ARPHRD_IEEE802;
748 else if (dev->type == ARPHRD_FDDI)
749 b->htype = ARPHRD_ETHER;
751 printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name);
752 b->htype = dev->type; /* can cause undefined behavior */
755 /* server_ip and your_ip address are both already zero per RFC2131 */
756 b->hlen = dev->addr_len;
757 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
758 b->secs = htons(jiffies_diff / HZ);
761 /* add DHCP options or BOOTP extensions */
763 if (ic_proto_enabled & IC_USE_DHCP)
764 ic_dhcp_init_options(b->exten);
767 ic_bootp_init_ext(b->exten);
769 /* Chain packet down the line... */
771 skb->protocol = htons(ETH_P_IP);
772 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
773 dev->broadcast, dev->dev_addr, skb->len) < 0 ||
774 dev_queue_xmit(skb) < 0)
780 * Copy BOOTP-supplied string if not already set.
782 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
788 memcpy(dest, src, len);
795 * Process BOOTP extensions.
797 static void __init ic_do_bootp_ext(u8 *ext)
802 #ifdef IPCONFIG_DEBUG
805 printk("DHCP/BOOTP: Got extension %d:",*ext);
806 for (c=ext+2; c<ext+2+ext[1]; c++)
812 case 1: /* Subnet mask */
813 if (ic_netmask == NONE)
814 memcpy(&ic_netmask, ext+1, 4);
816 case 3: /* Default gateway */
817 if (ic_gateway == NONE)
818 memcpy(&ic_gateway, ext+1, 4);
820 case 6: /* DNS server */
822 if (servers > CONF_NAMESERVERS_MAX)
823 servers = CONF_NAMESERVERS_MAX;
824 for (i = 0; i < servers; i++) {
825 if (ic_nameservers[i] == NONE)
826 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
829 case 12: /* Host name */
830 ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN);
831 ic_host_name_set = 1;
833 case 15: /* Domain name (DNS) */
834 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
836 case 17: /* Root path */
837 if (!root_server_path[0])
838 ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path));
840 case 40: /* NIS Domain name (_not_ DNS) */
841 ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN);
848 * Receive BOOTP reply.
850 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
857 if (dev_net(dev) != &init_net)
860 /* Perform verifications before taking the lock. */
861 if (skb->pkt_type == PACKET_OTHERHOST)
864 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
867 if (!pskb_may_pull(skb,
868 sizeof(struct iphdr) +
869 sizeof(struct udphdr)))
872 b = (struct bootp_pkt *)skb_network_header(skb);
875 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
878 /* Fragments are not supported */
879 if (h->frag_off & htons(IP_OFFSET | IP_MF)) {
881 printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented "
886 if (skb->len < ntohs(h->tot_len))
889 if (ip_fast_csum((char *) h, h->ihl))
892 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
895 if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
898 len = ntohs(b->udph.len) - sizeof(struct udphdr);
899 ext_len = len - (sizeof(*b) -
900 sizeof(struct iphdr) -
901 sizeof(struct udphdr) -
906 /* Ok the front looks good, make sure we can get at the rest. */
907 if (!pskb_may_pull(skb, skb->len))
910 b = (struct bootp_pkt *)skb_network_header(skb);
913 /* One reply at a time, please. */
914 spin_lock(&ic_recv_lock);
916 /* If we already have a reply, just drop the packet */
920 /* Find the ic_device that the packet arrived on */
922 while (d && d->dev != dev)
925 goto drop_unlock; /* should never happen */
927 /* Is it a reply to our BOOTP request? */
928 if (b->op != BOOTP_REPLY ||
931 printk(KERN_ERR "DHCP/BOOTP: Reply not for us, "
937 /* Parse extensions */
939 !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
940 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
944 if (ic_proto_enabled & IC_USE_DHCP) {
945 __be32 server_id = NONE;
949 while (ext < end && *ext != 0xff) {
951 if (*opt == 0) /* Padding */
957 case 53: /* Message type */
961 case 54: /* Server ID (IP address) */
963 memcpy(&server_id, opt + 2, 4);
968 #ifdef IPCONFIG_DEBUG
969 printk("DHCP: Got message type %d\n", mt);
974 /* While in the process of accepting one offer,
977 if (ic_myaddr != NONE)
980 /* Let's accept that offer. */
981 ic_myaddr = b->your_ip;
982 ic_servaddr = server_id;
983 #ifdef IPCONFIG_DEBUG
984 printk("DHCP: Offered address " NIPQUAD_FMT,
986 printk(" by server " NIPQUAD_FMT "\n",
987 NIPQUAD(ic_servaddr));
989 /* The DHCP indicated server address takes
990 * precedence over the bootp header one if
991 * they are different.
993 if ((server_id != NONE) &&
994 (b->server_ip != server_id))
995 b->server_ip = ic_servaddr;
999 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1006 /* Urque. Forget it*/
1012 ic_dhcp_msgtype = mt;
1015 #endif /* IPCONFIG_DHCP */
1018 while (ext < end && *ext != 0xff) {
1020 if (*opt == 0) /* Padding */
1024 ic_do_bootp_ext(opt);
1028 /* We have a winner! */
1030 ic_myaddr = b->your_ip;
1031 ic_servaddr = b->server_ip;
1032 if (ic_gateway == NONE && b->relay_ip)
1033 ic_gateway = b->relay_ip;
1034 if (ic_nameservers[0] == NONE)
1035 ic_nameservers[0] = ic_servaddr;
1036 ic_got_reply = IC_BOOTP;
1039 /* Show's over. Nothing to see here. */
1040 spin_unlock(&ic_recv_lock);
1043 /* Throw the packet out. */
1054 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1057 #ifdef IPCONFIG_DYNAMIC
1059 static int __init ic_dynamic(void)
1062 struct ic_device *d;
1063 unsigned long start_jiffies, timeout, jiff;
1064 int do_bootp = ic_proto_have_if & IC_BOOTP;
1065 int do_rarp = ic_proto_have_if & IC_RARP;
1068 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1069 * This routine gets only called when some pieces of information
1070 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1072 if (!ic_proto_enabled) {
1073 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1077 #ifdef IPCONFIG_BOOTP
1078 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1079 printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n");
1081 #ifdef IPCONFIG_RARP
1082 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1083 printk(KERN_ERR "RARP: No suitable device found.\n");
1086 if (!ic_proto_have_if)
1087 /* Error message already printed */
1093 #ifdef IPCONFIG_BOOTP
1097 #ifdef IPCONFIG_RARP
1103 * Send requests and wait, until we get an answer. This loop
1104 * seems to be a terrible waste of CPU time, but actually there is
1105 * only one process running at all, so we don't need to use any
1106 * scheduler functions.
1107 * [Actually we could now, but the nothing else running note still
1110 printk(KERN_NOTICE "Sending %s%s%s requests .",
1112 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1113 (do_bootp && do_rarp) ? " and " : "",
1114 do_rarp ? "RARP" : "");
1116 start_jiffies = jiffies;
1118 retries = CONF_SEND_RETRIES;
1119 get_random_bytes(&timeout, sizeof(timeout));
1120 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM);
1122 #ifdef IPCONFIG_BOOTP
1123 if (do_bootp && (d->able & IC_BOOTP))
1124 ic_bootp_send_if(d, jiffies - start_jiffies);
1126 #ifdef IPCONFIG_RARP
1127 if (do_rarp && (d->able & IC_RARP))
1131 jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout);
1132 while (time_before(jiffies, jiff) && !ic_got_reply)
1133 schedule_timeout_uninterruptible(1);
1134 #ifdef IPCONFIG_DHCP
1135 /* DHCP isn't done until we get a DHCPACK. */
1136 if ((ic_got_reply & IC_BOOTP)
1137 && (ic_proto_enabled & IC_USE_DHCP)
1138 && ic_dhcp_msgtype != DHCPACK)
1144 #endif /* IPCONFIG_DHCP */
1155 printk(" timed out!\n");
1161 timeout = timeout CONF_TIMEOUT_MULT;
1162 if (timeout > CONF_TIMEOUT_MAX)
1163 timeout = CONF_TIMEOUT_MAX;
1168 #ifdef IPCONFIG_BOOTP
1172 #ifdef IPCONFIG_RARP
1177 if (!ic_got_reply) {
1182 printk("IP-Config: Got %s answer from " NIPQUAD_FMT ", ",
1183 ((ic_got_reply & IC_RARP) ? "RARP"
1184 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1185 NIPQUAD(ic_servaddr));
1186 printk("my address is " NIPQUAD_FMT "\n", NIPQUAD(ic_myaddr));
1191 #endif /* IPCONFIG_DYNAMIC */
1193 #ifdef CONFIG_PROC_FS
1195 static int pnp_seq_show(struct seq_file *seq, void *v)
1199 if (ic_proto_used & IC_PROTO)
1200 seq_printf(seq, "#PROTO: %s\n",
1201 (ic_proto_used & IC_RARP) ? "RARP"
1202 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1204 seq_puts(seq, "#MANUAL\n");
1208 "domain %s\n", ic_domain);
1209 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1210 if (ic_nameservers[i] != NONE)
1212 "nameserver " NIPQUAD_FMT "\n",
1213 NIPQUAD(ic_nameservers[i]));
1215 if (ic_servaddr != NONE)
1217 "bootserver " NIPQUAD_FMT "\n",
1218 NIPQUAD(ic_servaddr));
1222 static int pnp_seq_open(struct inode *indoe, struct file *file)
1224 return single_open(file, pnp_seq_show, NULL);
1227 static const struct file_operations pnp_seq_fops = {
1228 .owner = THIS_MODULE,
1229 .open = pnp_seq_open,
1231 .llseek = seq_lseek,
1232 .release = single_release,
1234 #endif /* CONFIG_PROC_FS */
1237 * Extract IP address from the parameter string if needed. Note that we
1238 * need to have root_server_addr set _before_ IPConfig gets called as it
1241 __be32 __init root_nfs_parse_addr(char *name)
1248 while (octets < 4) {
1249 while (*cp >= '0' && *cp <= '9')
1251 if (cp == cq || cp - cq > 3)
1253 if (*cp == '.' || octets == 3)
1259 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1262 addr = in_aton(name);
1263 memmove(name, cp, strlen(cp) + 1);
1271 * IP Autoconfig dispatcher.
1274 static int __init ip_auto_config(void)
1278 #ifdef CONFIG_PROC_FS
1279 proc_net_fops_create(&init_net, "pnp", S_IRUGO, &pnp_seq_fops);
1280 #endif /* CONFIG_PROC_FS */
1285 DBG(("IP-Config: Entered.\n"));
1286 #ifdef IPCONFIG_DYNAMIC
1289 /* Give hardware a chance to settle */
1290 msleep(CONF_PRE_OPEN);
1292 /* Setup all network devices */
1293 if (ic_open_devs() < 0)
1296 /* Give drivers a chance to settle */
1297 ssleep(CONF_POST_OPEN);
1300 * If the config information is insufficient (e.g., our IP address or
1301 * IP address of the boot server is missing or we have multiple network
1302 * interfaces and no default was set), use BOOTP or RARP to get the
1305 if (ic_myaddr == NONE ||
1306 #ifdef CONFIG_ROOT_NFS
1307 (root_server_addr == NONE
1308 && ic_servaddr == NONE
1309 && ROOT_DEV == Root_NFS) ||
1311 ic_first_dev->next) {
1312 #ifdef IPCONFIG_DYNAMIC
1314 int retries = CONF_OPEN_RETRIES;
1316 if (ic_dynamic() < 0) {
1320 * I don't know why, but sometimes the
1321 * eepro100 driver (at least) gets upset and
1322 * doesn't work the first time it's opened.
1323 * But then if you close it and reopen it, it
1324 * works just fine. So we need to try that at
1325 * least once before giving up.
1327 * Also, if the root will be NFS-mounted, we
1328 * have nowhere to go if DHCP fails. So we
1329 * just have to keep trying forever.
1333 #ifdef CONFIG_ROOT_NFS
1334 if (ROOT_DEV == Root_NFS) {
1336 "IP-Config: Retrying forever (NFS root)...\n");
1343 "IP-Config: Reopening network devices...\n");
1347 /* Oh, well. At least we tried. */
1348 printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n");
1351 #else /* !DYNAMIC */
1352 printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n");
1355 #endif /* IPCONFIG_DYNAMIC */
1357 /* Device selected manually or only one device -> use it */
1358 ic_dev = ic_first_dev->dev;
1361 addr = root_nfs_parse_addr(root_server_path);
1362 if (root_server_addr == NONE)
1363 root_server_addr = addr;
1366 * Use defaults whereever applicable.
1368 if (ic_defaults() < 0)
1372 * Close all network devices except the device we've
1373 * autoconfigured and set up routes.
1376 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1380 * Record which protocol was actually used.
1382 #ifdef IPCONFIG_DYNAMIC
1383 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1386 #ifndef IPCONFIG_SILENT
1388 * Clue in the operator.
1390 printk("IP-Config: Complete:");
1391 printk("\n device=%s", ic_dev->name);
1392 printk(", addr=" NIPQUAD_FMT, NIPQUAD(ic_myaddr));
1393 printk(", mask=" NIPQUAD_FMT, NIPQUAD(ic_netmask));
1394 printk(", gw=" NIPQUAD_FMT, NIPQUAD(ic_gateway));
1395 printk(",\n host=%s, domain=%s, nis-domain=%s",
1396 utsname()->nodename, ic_domain, utsname()->domainname);
1397 printk(",\n bootserver=" NIPQUAD_FMT, NIPQUAD(ic_servaddr));
1398 printk(", rootserver=" NIPQUAD_FMT, NIPQUAD(root_server_addr));
1399 printk(", rootpath=%s", root_server_path);
1401 #endif /* !SILENT */
1406 late_initcall(ip_auto_config);
1410 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1411 * command line parameter. See Documentation/filesystems/nfsroot.txt.
1413 static int __init ic_proto_name(char *name)
1415 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1418 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1421 #ifdef CONFIG_IP_PNP_DHCP
1422 else if (!strcmp(name, "dhcp")) {
1423 ic_proto_enabled &= ~IC_RARP;
1427 #ifdef CONFIG_IP_PNP_BOOTP
1428 else if (!strcmp(name, "bootp")) {
1429 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1433 #ifdef CONFIG_IP_PNP_RARP
1434 else if (!strcmp(name, "rarp")) {
1435 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1439 #ifdef IPCONFIG_DYNAMIC
1440 else if (!strcmp(name, "both")) {
1441 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1448 static int __init ip_auto_config_setup(char *addrs)
1453 ic_set_manually = 1;
1457 * If any dhcp, bootp etc options are set, leave autoconfig on
1458 * and skip the below static IP processing.
1460 if (ic_proto_name(addrs))
1463 /* If no static IP is given, turn off autoconfig and bail. */
1465 strcmp(addrs, "off") == 0 ||
1466 strcmp(addrs, "none") == 0) {
1471 /* Parse string for static IP assignment. */
1474 if ((cp = strchr(ip, ':')))
1476 if (strlen(ip) > 0) {
1477 DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip));
1480 if ((ic_myaddr = in_aton(ip)) == ANY)
1484 if ((ic_servaddr = in_aton(ip)) == ANY)
1488 if ((ic_gateway = in_aton(ip)) == ANY)
1492 if ((ic_netmask = in_aton(ip)) == ANY)
1496 if ((dp = strchr(ip, '.'))) {
1498 strlcpy(utsname()->domainname, dp,
1499 sizeof(utsname()->domainname));
1501 strlcpy(utsname()->nodename, ip,
1502 sizeof(utsname()->nodename));
1503 ic_host_name_set = 1;
1506 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1509 if (ic_proto_name(ip) == 0 &&
1510 ic_myaddr == NONE) {
1523 static int __init nfsaddrs_config_setup(char *addrs)
1525 return ip_auto_config_setup(addrs);
1528 static int __init vendor_class_identifier_setup(char *addrs)
1530 if (strlcpy(vendor_class_identifier, addrs,
1531 sizeof(vendor_class_identifier))
1532 >= sizeof(vendor_class_identifier))
1533 printk(KERN_WARNING "DHCP: vendorclass too long, truncated to \"%s\"",
1534 vendor_class_identifier);
1538 __setup("ip=", ip_auto_config_setup);
1539 __setup("nfsaddrs=", nfsaddrs_config_setup);
1540 __setup("dhcpclass=", vendor_class_identifier_setup);