1 // SPDX-License-Identifier: GPL-2.0
3 * Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or
4 * user-supplied information to configure own IP address and routes.
6 * Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
8 * Derived from network configuration code in fs/nfs/nfsroot.c,
9 * originally Copyright (C) 1995, 1996 Gero Kuhlmann and me.
11 * BOOTP rewritten to construct and analyse packets itself instead
12 * of misusing the IP layer. num_bugs_causing_wrong_arp_replies--;
13 * -- MJ, December 1998
15 * Fixed ip_auto_config_setup calling at startup in the new "Linker Magic"
16 * initialization scheme.
17 * - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999
19 * DHCP support added. To users this looks like a whole separate
20 * protocol, but we know it's just a bag on the side of BOOTP.
21 * -- Chip Salzenberg <chip@valinux.com>, May 2000
23 * Ported DHCP support from 2.2.16 to 2.4.0-test4
24 * -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000
26 * Merged changes from 2.2.19 into 2.4.3
27 * -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001
29 * Multiple Nameservers in /proc/net/pnp
30 * -- Josef Siemes <jsiemes@web.de>, Aug 2002
33 #include <linux/types.h>
34 #include <linux/string.h>
35 #include <linux/kernel.h>
36 #include <linux/jiffies.h>
37 #include <linux/random.h>
38 #include <linux/init.h>
39 #include <linux/utsname.h>
42 #include <linux/inet.h>
43 #include <linux/inetdevice.h>
44 #include <linux/netdevice.h>
45 #include <linux/if_arp.h>
46 #include <linux/skbuff.h>
48 #include <linux/socket.h>
49 #include <linux/route.h>
50 #include <linux/udp.h>
51 #include <linux/proc_fs.h>
52 #include <linux/seq_file.h>
53 #include <linux/major.h>
54 #include <linux/root_dev.h>
55 #include <linux/delay.h>
56 #include <linux/nfs_fs.h>
57 #include <linux/slab.h>
58 #include <linux/export.h>
59 #include <net/net_namespace.h>
63 #include <net/ipconfig.h>
64 #include <net/route.h>
66 #include <linux/uaccess.h>
67 #include <net/checksum.h>
68 #include <asm/processor.h>
70 #if defined(CONFIG_IP_PNP_DHCP)
73 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
74 #define IPCONFIG_BOOTP
76 #if defined(CONFIG_IP_PNP_RARP)
79 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
80 #define IPCONFIG_DYNAMIC
83 /* Define the friendly delay before and after opening net devices */
84 #define CONF_POST_OPEN 10 /* After opening: 10 msecs */
85 #define CONF_CARRIER_TIMEOUT 120000 /* Wait for carrier timeout */
87 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
88 #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
89 #define CONF_SEND_RETRIES 6 /* Send six requests per open */
90 #define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */
91 #define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */
92 #define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */
93 #define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */
94 #define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
95 - '3' from resolv.h */
97 #define NONE cpu_to_be32(INADDR_NONE)
98 #define ANY cpu_to_be32(INADDR_ANY)
101 * Public IP configuration
104 /* This is used by platforms which might be able to set the ipconfig
105 * variables using firmware environment vars. If this is set, it will
106 * ignore such firmware variables.
108 int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
110 static int ic_enable __initdata; /* IP config enabled? */
112 /* Protocol choice */
113 int ic_proto_enabled __initdata = 0
114 #ifdef IPCONFIG_BOOTP
117 #ifdef CONFIG_IP_PNP_DHCP
125 static int ic_host_name_set __initdata; /* Host name set by us? */
127 __be32 ic_myaddr = NONE; /* My IP address */
128 static __be32 ic_netmask = NONE; /* Netmask for local subnet */
129 __be32 ic_gateway = NONE; /* Gateway IP address */
131 #ifdef IPCONFIG_DYNAMIC
132 static __be32 ic_addrservaddr = NONE; /* IP Address of the IP addresses'server */
135 __be32 ic_servaddr = NONE; /* Boot server IP address */
137 __be32 root_server_addr = NONE; /* Address of NFS server */
138 u8 root_server_path[256] = { 0, }; /* Path to mount as root */
140 /* vendor class identifier */
141 static char vendor_class_identifier[253] __initdata;
143 #if defined(CONFIG_IP_PNP_DHCP)
144 static char dhcp_client_identifier[253] __initdata;
147 /* Persistent data: */
149 #ifdef IPCONFIG_DYNAMIC
150 static int ic_proto_used; /* Protocol used, if any */
152 #define ic_proto_used 0
154 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
155 static u8 ic_domain[64]; /* DNS (not NIS) domain name */
161 /* Name of user-selected boot device */
162 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
164 /* Protocols supported by available interfaces */
165 static int ic_proto_have_if __initdata;
167 /* MTU for boot device */
168 static int ic_dev_mtu __initdata;
170 #ifdef IPCONFIG_DYNAMIC
171 static DEFINE_SPINLOCK(ic_recv_lock);
172 static volatile int ic_got_reply __initdata; /* Proto(s) that replied */
175 static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */
184 struct ic_device *next;
185 struct net_device *dev;
186 unsigned short flags;
191 static struct ic_device *ic_first_dev __initdata; /* List of open device */
192 static struct ic_device *ic_dev __initdata; /* Selected device */
194 static bool __init ic_is_init_dev(struct net_device *dev)
196 if (dev->flags & IFF_LOOPBACK)
198 return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
199 (!(dev->flags & IFF_LOOPBACK) &&
200 (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
201 strncmp(dev->name, "dummy", 5));
204 static int __init ic_open_devs(void)
206 struct ic_device *d, **last;
207 struct net_device *dev;
208 unsigned short oflags;
209 unsigned long start, next_msg;
211 last = &ic_first_dev;
214 /* bring loopback and DSA master network devices up first */
215 for_each_netdev(&init_net, dev) {
216 if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
218 if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
219 pr_err("IP-Config: Failed to open %s\n", dev->name);
222 for_each_netdev(&init_net, dev) {
223 if (ic_is_init_dev(dev)) {
228 pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
229 dev->name, dev->mtu);
230 if (!(dev->flags & IFF_NOARP))
232 able &= ic_proto_enabled;
233 if (ic_proto_enabled && !able)
236 if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
237 pr_err("IP-Config: Failed to open %s\n",
241 if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
251 get_random_bytes(&d->xid, sizeof(__be32));
254 ic_proto_have_if |= able;
255 pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
256 dev->name, able, d->xid);
260 /* no point in waiting if we could not bring up at least one device */
264 /* wait for a carrier on at least one device */
266 next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
267 while (time_before(jiffies, start +
268 msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
271 for_each_netdev(&init_net, dev)
272 if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
277 if (time_before(jiffies, next_msg))
280 elapsed = jiffies_to_msecs(jiffies - start);
281 wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
282 pr_info("Waiting up to %d more seconds for network.\n", wait);
283 next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
291 if (user_dev_name[0])
292 pr_err("IP-Config: Device `%s' not found\n",
295 pr_err("IP-Config: No network devices available\n");
301 static void __init ic_close_devs(void)
303 struct ic_device *d, *next;
304 struct net_device *dev;
311 if (d != ic_dev && !netdev_uses_dsa(dev)) {
312 pr_debug("IP-Config: Downing %s\n", dev->name);
313 dev_change_flags(dev, d->flags);
321 * Interface to various network functions.
325 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
327 sin->sin_family = AF_INET;
328 sin->sin_addr.s_addr = addr;
329 sin->sin_port = port;
333 * Set up interface addresses and routes.
336 static int __init ic_setup_if(void)
339 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
342 memset(&ir, 0, sizeof(ir));
343 strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
344 set_sockaddr(sin, ic_myaddr, 0);
345 if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
346 pr_err("IP-Config: Unable to set interface address (%d)\n",
350 set_sockaddr(sin, ic_netmask, 0);
351 if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
352 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
356 set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
357 if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
358 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
362 /* Handle the case where we need non-standard MTU on the boot link (a network
363 * using jumbo frames, for instance). If we can't set the mtu, don't error
364 * out, we'll try to muddle along.
366 if (ic_dev_mtu != 0) {
368 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
369 pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
376 static int __init ic_setup_routes(void)
378 /* No need to setup device routes, only the default route... */
380 if (ic_gateway != NONE) {
384 memset(&rm, 0, sizeof(rm));
385 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
386 pr_err("IP-Config: Gateway not on directly connected network\n");
389 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
390 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
391 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
392 rm.rt_flags = RTF_UP | RTF_GATEWAY;
393 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
394 pr_err("IP-Config: Cannot add default route (%d)\n",
404 * Fill in default values for all missing parameters.
407 static int __init ic_defaults(void)
410 * At this point we have no userspace running so need not
411 * claim locks on system_utsname
414 if (!ic_host_name_set)
415 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
417 if (root_server_addr == NONE)
418 root_server_addr = ic_servaddr;
420 if (ic_netmask == NONE) {
421 if (IN_CLASSA(ntohl(ic_myaddr)))
422 ic_netmask = htonl(IN_CLASSA_NET);
423 else if (IN_CLASSB(ntohl(ic_myaddr)))
424 ic_netmask = htonl(IN_CLASSB_NET);
425 else if (IN_CLASSC(ntohl(ic_myaddr)))
426 ic_netmask = htonl(IN_CLASSC_NET);
428 pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
432 pr_notice("IP-Config: Guessing netmask %pI4\n",
445 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
447 static struct packet_type rarp_packet_type __initdata = {
448 .type = cpu_to_be16(ETH_P_RARP),
449 .func = ic_rarp_recv,
452 static inline void __init ic_rarp_init(void)
454 dev_add_pack(&rarp_packet_type);
457 static inline void __init ic_rarp_cleanup(void)
459 dev_remove_pack(&rarp_packet_type);
463 * Process received RARP packet.
466 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
469 unsigned char *rarp_ptr;
471 unsigned char *tha; /* t for "target" */
474 if (!net_eq(dev_net(dev), &init_net))
477 skb = skb_share_check(skb, GFP_ATOMIC);
481 if (!pskb_may_pull(skb, sizeof(struct arphdr)))
484 /* Basic sanity checks can be done without the lock. */
485 rarp = (struct arphdr *)skb_transport_header(skb);
487 /* If this test doesn't pass, it's not IP, or we should
490 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
493 /* If it's not a RARP reply, delete it. */
494 if (rarp->ar_op != htons(ARPOP_RREPLY))
497 /* If it's not Ethernet, delete it. */
498 if (rarp->ar_pro != htons(ETH_P_IP))
501 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
504 /* OK, it is all there and looks valid, process... */
505 rarp = (struct arphdr *)skb_transport_header(skb);
506 rarp_ptr = (unsigned char *) (rarp + 1);
508 /* One reply at a time, please. */
509 spin_lock(&ic_recv_lock);
511 /* If we already have a reply, just drop the packet */
515 /* Find the ic_device that the packet arrived on */
517 while (d && d->dev != dev)
520 goto drop_unlock; /* should never happen */
522 /* Extract variable-width fields */
523 rarp_ptr += dev->addr_len;
524 memcpy(&sip, rarp_ptr, 4);
527 rarp_ptr += dev->addr_len;
528 memcpy(&tip, rarp_ptr, 4);
530 /* Discard packets which are not meant for us. */
531 if (memcmp(tha, dev->dev_addr, dev->addr_len))
534 /* Discard packets which are not from specified server. */
535 if (ic_servaddr != NONE && ic_servaddr != sip)
538 /* We have a winner! */
540 if (ic_myaddr == NONE)
543 ic_addrservaddr = sip;
544 ic_got_reply = IC_RARP;
547 /* Show's over. Nothing to see here. */
548 spin_unlock(&ic_recv_lock);
551 /* Throw the packet out. */
558 * Send RARP request packet over a single interface.
560 static void __init ic_rarp_send_if(struct ic_device *d)
562 struct net_device *dev = d->dev;
563 arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
564 dev->dev_addr, dev->dev_addr);
569 * Predefine Nameservers
571 static inline void __init ic_nameservers_predef(void)
575 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
576 ic_nameservers[i] = NONE;
580 * DHCP/BOOTP support.
583 #ifdef IPCONFIG_BOOTP
585 struct bootp_pkt { /* BOOTP packet format */
586 struct iphdr iph; /* IP header */
587 struct udphdr udph; /* UDP header */
588 u8 op; /* 1=request, 2=reply */
589 u8 htype; /* HW address type */
590 u8 hlen; /* HW address length */
591 u8 hops; /* Used only by gateways */
592 __be32 xid; /* Transaction ID */
593 __be16 secs; /* Seconds since we started */
594 __be16 flags; /* Just what it says */
595 __be32 client_ip; /* Client's IP address if known */
596 __be32 your_ip; /* Assigned IP address */
597 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
598 __be32 relay_ip; /* IP address of BOOTP relay */
599 u8 hw_addr[16]; /* Client's HW address */
600 u8 serv_name[64]; /* Server host name */
601 u8 boot_file[128]; /* Name of boot file */
602 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
606 #define BOOTP_REQUEST 1
607 #define BOOTP_REPLY 2
609 /* DHCP message types */
610 #define DHCPDISCOVER 1
612 #define DHCPREQUEST 3
613 #define DHCPDECLINE 4
616 #define DHCPRELEASE 7
619 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
621 static struct packet_type bootp_packet_type __initdata = {
622 .type = cpu_to_be16(ETH_P_IP),
623 .func = ic_bootp_recv,
627 * Initialize DHCP/BOOTP extension fields in the request.
630 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
635 ic_dhcp_init_options(u8 *options, struct ic_device *d)
637 u8 mt = ((ic_servaddr == NONE)
638 ? DHCPDISCOVER : DHCPREQUEST);
642 pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
644 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
647 *e++ = 53; /* DHCP message type */
651 if (mt == DHCPREQUEST) {
652 *e++ = 54; /* Server ID (IP address) */
654 memcpy(e, &ic_servaddr, 4);
657 *e++ = 50; /* Requested IP address */
659 memcpy(e, &ic_myaddr, 4);
665 static const u8 ic_req_params[] = {
667 3, /* Default gateway */
670 15, /* Domain name */
673 40, /* NIS domain name */
676 *e++ = 55; /* Parameter request list */
677 *e++ = sizeof(ic_req_params);
678 memcpy(e, ic_req_params, sizeof(ic_req_params));
679 e += sizeof(ic_req_params);
681 if (ic_host_name_set) {
682 *e++ = 12; /* host-name */
683 len = strlen(utsname()->nodename);
685 memcpy(e, utsname()->nodename, len);
688 if (*vendor_class_identifier) {
689 pr_info("DHCP: sending class identifier \"%s\"\n",
690 vendor_class_identifier);
691 *e++ = 60; /* Class-identifier */
692 len = strlen(vendor_class_identifier);
694 memcpy(e, vendor_class_identifier, len);
697 len = strlen(dhcp_client_identifier + 1);
698 /* the minimum length of identifier is 2, include 1 byte type,
699 * and can not be larger than the length of options
701 if (len >= 1 && len < 312 - (e - options) - 1) {
704 memcpy(e, dhcp_client_identifier, len + 1);
709 *e++ = 255; /* End of the list */
712 #endif /* IPCONFIG_DHCP */
714 static void __init ic_bootp_init_ext(u8 *e)
716 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
718 *e++ = 1; /* Subnet mask request */
721 *e++ = 3; /* Default gateway request */
724 *e++ = 5; /* Name server request */
727 *e++ = 12; /* Host name request */
730 *e++ = 40; /* NIS Domain name request */
733 *e++ = 17; /* Boot path */
737 *e++ = 57; /* set extension buffer size for reply */
739 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
742 *e++ = 255; /* End of the list */
747 * Initialize the DHCP/BOOTP mechanism.
749 static inline void __init ic_bootp_init(void)
751 ic_nameservers_predef();
753 dev_add_pack(&bootp_packet_type);
758 * DHCP/BOOTP cleanup.
760 static inline void __init ic_bootp_cleanup(void)
762 dev_remove_pack(&bootp_packet_type);
767 * Send DHCP/BOOTP request to single interface.
769 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
771 struct net_device *dev = d->dev;
775 int hlen = LL_RESERVED_SPACE(dev);
776 int tlen = dev->needed_tailroom;
778 /* Allocate packet */
779 skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
783 skb_reserve(skb, hlen);
784 b = skb_put_zero(skb, sizeof(struct bootp_pkt));
786 /* Construct IP header */
787 skb_reset_network_header(skb);
791 h->tot_len = htons(sizeof(struct bootp_pkt));
792 h->frag_off = htons(IP_DF);
794 h->protocol = IPPROTO_UDP;
795 h->daddr = htonl(INADDR_BROADCAST);
796 h->check = ip_fast_csum((unsigned char *) h, h->ihl);
798 /* Construct UDP header */
799 b->udph.source = htons(68);
800 b->udph.dest = htons(67);
801 b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
802 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
804 /* Construct DHCP/BOOTP header */
805 b->op = BOOTP_REQUEST;
806 if (dev->type < 256) /* check for false types */
807 b->htype = dev->type;
808 else if (dev->type == ARPHRD_FDDI)
809 b->htype = ARPHRD_ETHER;
811 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
813 b->htype = dev->type; /* can cause undefined behavior */
816 /* server_ip and your_ip address are both already zero per RFC2131 */
817 b->hlen = dev->addr_len;
818 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
819 b->secs = htons(jiffies_diff / HZ);
822 /* add DHCP options or BOOTP extensions */
824 if (ic_proto_enabled & IC_USE_DHCP)
825 ic_dhcp_init_options(b->exten, d);
828 ic_bootp_init_ext(b->exten);
830 /* Chain packet down the line... */
832 skb->protocol = htons(ETH_P_IP);
833 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
834 dev->broadcast, dev->dev_addr, skb->len) < 0) {
840 if (dev_queue_xmit(skb) < 0)
846 * Copy BOOTP-supplied string if not already set.
848 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
854 memcpy(dest, src, len);
861 * Process BOOTP extensions.
863 static void __init ic_do_bootp_ext(u8 *ext)
871 pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
872 for (c=ext+2; c<ext+2+ext[1]; c++)
873 pr_debug(" %02x", *c);
877 case 1: /* Subnet mask */
878 if (ic_netmask == NONE)
879 memcpy(&ic_netmask, ext+1, 4);
881 case 3: /* Default gateway */
882 if (ic_gateway == NONE)
883 memcpy(&ic_gateway, ext+1, 4);
885 case 6: /* DNS server */
887 if (servers > CONF_NAMESERVERS_MAX)
888 servers = CONF_NAMESERVERS_MAX;
889 for (i = 0; i < servers; i++) {
890 if (ic_nameservers[i] == NONE)
891 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
894 case 12: /* Host name */
895 ic_bootp_string(utsname()->nodename, ext+1, *ext,
897 ic_host_name_set = 1;
899 case 15: /* Domain name (DNS) */
900 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
902 case 17: /* Root path */
903 if (!root_server_path[0])
904 ic_bootp_string(root_server_path, ext+1, *ext,
905 sizeof(root_server_path));
907 case 26: /* Interface MTU */
908 memcpy(&mtu, ext+1, sizeof(mtu));
909 ic_dev_mtu = ntohs(mtu);
911 case 40: /* NIS Domain name (_not_ DNS) */
912 ic_bootp_string(utsname()->domainname, ext+1, *ext,
920 * Receive BOOTP reply.
922 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
929 if (!net_eq(dev_net(dev), &init_net))
932 /* Perform verifications before taking the lock. */
933 if (skb->pkt_type == PACKET_OTHERHOST)
936 skb = skb_share_check(skb, GFP_ATOMIC);
940 if (!pskb_may_pull(skb,
941 sizeof(struct iphdr) +
942 sizeof(struct udphdr)))
945 b = (struct bootp_pkt *)skb_network_header(skb);
948 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
951 /* Fragments are not supported */
952 if (ip_is_fragment(h)) {
953 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
957 if (skb->len < ntohs(h->tot_len))
960 if (ip_fast_csum((char *) h, h->ihl))
963 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
966 if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
969 len = ntohs(b->udph.len) - sizeof(struct udphdr);
970 ext_len = len - (sizeof(*b) -
971 sizeof(struct iphdr) -
972 sizeof(struct udphdr) -
977 /* Ok the front looks good, make sure we can get at the rest. */
978 if (!pskb_may_pull(skb, skb->len))
981 b = (struct bootp_pkt *)skb_network_header(skb);
984 /* One reply at a time, please. */
985 spin_lock(&ic_recv_lock);
987 /* If we already have a reply, just drop the packet */
991 /* Find the ic_device that the packet arrived on */
993 while (d && d->dev != dev)
996 goto drop_unlock; /* should never happen */
998 /* Is it a reply to our BOOTP request? */
999 if (b->op != BOOTP_REPLY ||
1001 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1002 d->dev->name, b->op, b->xid);
1006 /* Parse extensions */
1008 !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1009 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1012 #ifdef IPCONFIG_DHCP
1013 if (ic_proto_enabled & IC_USE_DHCP) {
1014 __be32 server_id = NONE;
1018 while (ext < end && *ext != 0xff) {
1020 if (*opt == 0) /* Padding */
1026 case 53: /* Message type */
1030 case 54: /* Server ID (IP address) */
1032 memcpy(&server_id, opt + 2, 4);
1037 pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1041 /* While in the process of accepting one offer,
1042 * ignore all others.
1044 if (ic_myaddr != NONE)
1047 /* Let's accept that offer. */
1048 ic_myaddr = b->your_ip;
1049 ic_servaddr = server_id;
1050 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1051 &ic_myaddr, &b->iph.saddr);
1052 /* The DHCP indicated server address takes
1053 * precedence over the bootp header one if
1054 * they are different.
1056 if ((server_id != NONE) &&
1057 (b->server_ip != server_id))
1058 b->server_ip = ic_servaddr;
1062 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1069 /* Urque. Forget it*/
1075 ic_dhcp_msgtype = mt;
1078 #endif /* IPCONFIG_DHCP */
1081 while (ext < end && *ext != 0xff) {
1083 if (*opt == 0) /* Padding */
1087 ic_do_bootp_ext(opt);
1091 /* We have a winner! */
1093 ic_myaddr = b->your_ip;
1094 ic_servaddr = b->server_ip;
1095 ic_addrservaddr = b->iph.saddr;
1096 if (ic_gateway == NONE && b->relay_ip)
1097 ic_gateway = b->relay_ip;
1098 if (ic_nameservers[0] == NONE)
1099 ic_nameservers[0] = ic_servaddr;
1100 ic_got_reply = IC_BOOTP;
1103 /* Show's over. Nothing to see here. */
1104 spin_unlock(&ic_recv_lock);
1107 /* Throw the packet out. */
1118 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1121 #ifdef IPCONFIG_DYNAMIC
1123 static int __init ic_dynamic(void)
1126 struct ic_device *d;
1127 unsigned long start_jiffies, timeout, jiff;
1128 int do_bootp = ic_proto_have_if & IC_BOOTP;
1129 int do_rarp = ic_proto_have_if & IC_RARP;
1132 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1133 * This routine gets only called when some pieces of information
1134 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1136 if (!ic_proto_enabled) {
1137 pr_err("IP-Config: Incomplete network configuration information\n");
1141 #ifdef IPCONFIG_BOOTP
1142 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1143 pr_err("DHCP/BOOTP: No suitable device found\n");
1145 #ifdef IPCONFIG_RARP
1146 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1147 pr_err("RARP: No suitable device found\n");
1150 if (!ic_proto_have_if)
1151 /* Error message already printed */
1157 #ifdef IPCONFIG_BOOTP
1161 #ifdef IPCONFIG_RARP
1167 * Send requests and wait, until we get an answer. This loop
1168 * seems to be a terrible waste of CPU time, but actually there is
1169 * only one process running at all, so we don't need to use any
1170 * scheduler functions.
1171 * [Actually we could now, but the nothing else running note still
1174 pr_notice("Sending %s%s%s requests .",
1176 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1177 (do_bootp && do_rarp) ? " and " : "",
1178 do_rarp ? "RARP" : "");
1180 start_jiffies = jiffies;
1182 retries = CONF_SEND_RETRIES;
1183 get_random_bytes(&timeout, sizeof(timeout));
1184 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1186 #ifdef IPCONFIG_BOOTP
1187 if (do_bootp && (d->able & IC_BOOTP))
1188 ic_bootp_send_if(d, jiffies - start_jiffies);
1190 #ifdef IPCONFIG_RARP
1191 if (do_rarp && (d->able & IC_RARP))
1196 jiff = jiffies + timeout;
1197 while (time_before(jiffies, jiff) && !ic_got_reply)
1198 schedule_timeout_uninterruptible(1);
1200 #ifdef IPCONFIG_DHCP
1201 /* DHCP isn't done until we get a DHCPACK. */
1202 if ((ic_got_reply & IC_BOOTP) &&
1203 (ic_proto_enabled & IC_USE_DHCP) &&
1204 ic_dhcp_msgtype != DHCPACK) {
1206 /* continue on device that got the reply */
1211 #endif /* IPCONFIG_DHCP */
1222 pr_cont(" timed out!\n");
1228 timeout = timeout CONF_TIMEOUT_MULT;
1229 if (timeout > CONF_TIMEOUT_MAX)
1230 timeout = CONF_TIMEOUT_MAX;
1235 #ifdef IPCONFIG_BOOTP
1239 #ifdef IPCONFIG_RARP
1244 if (!ic_got_reply) {
1249 pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1250 ((ic_got_reply & IC_RARP) ? "RARP"
1251 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1252 &ic_addrservaddr, &ic_myaddr);
1257 #endif /* IPCONFIG_DYNAMIC */
1259 #ifdef CONFIG_PROC_FS
1261 static int pnp_seq_show(struct seq_file *seq, void *v)
1265 if (ic_proto_used & IC_PROTO)
1266 seq_printf(seq, "#PROTO: %s\n",
1267 (ic_proto_used & IC_RARP) ? "RARP"
1268 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1270 seq_puts(seq, "#MANUAL\n");
1274 "domain %s\n", ic_domain);
1275 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1276 if (ic_nameservers[i] != NONE)
1277 seq_printf(seq, "nameserver %pI4\n",
1278 &ic_nameservers[i]);
1280 if (ic_servaddr != NONE)
1281 seq_printf(seq, "bootserver %pI4\n",
1286 static int pnp_seq_open(struct inode *indoe, struct file *file)
1288 return single_open(file, pnp_seq_show, NULL);
1291 static const struct file_operations pnp_seq_fops = {
1292 .open = pnp_seq_open,
1294 .llseek = seq_lseek,
1295 .release = single_release,
1297 #endif /* CONFIG_PROC_FS */
1300 * Extract IP address from the parameter string if needed. Note that we
1301 * need to have root_server_addr set _before_ IPConfig gets called as it
1304 __be32 __init root_nfs_parse_addr(char *name)
1311 while (octets < 4) {
1312 while (*cp >= '0' && *cp <= '9')
1314 if (cp == cq || cp - cq > 3)
1316 if (*cp == '.' || octets == 3)
1322 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1325 addr = in_aton(name);
1326 memmove(name, cp, strlen(cp) + 1);
1333 #define DEVICE_WAIT_MAX 12 /* 12 seconds */
1335 static int __init wait_for_devices(void)
1339 for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1340 struct net_device *dev;
1344 for_each_netdev(&init_net, dev) {
1345 if (ic_is_init_dev(dev)) {
1359 * IP Autoconfig dispatcher.
1362 static int __init ip_auto_config(void)
1365 #ifdef IPCONFIG_DYNAMIC
1366 int retries = CONF_OPEN_RETRIES;
1371 #ifdef CONFIG_PROC_FS
1372 proc_create("pnp", 0444, init_net.proc_net, &pnp_seq_fops);
1373 #endif /* CONFIG_PROC_FS */
1378 pr_debug("IP-Config: Entered.\n");
1379 #ifdef IPCONFIG_DYNAMIC
1382 /* Wait for devices to appear */
1383 err = wait_for_devices();
1387 /* Setup all network devices */
1388 err = ic_open_devs();
1392 /* Give drivers a chance to settle */
1393 msleep(CONF_POST_OPEN);
1396 * If the config information is insufficient (e.g., our IP address or
1397 * IP address of the boot server is missing or we have multiple network
1398 * interfaces and no default was set), use BOOTP or RARP to get the
1401 if (ic_myaddr == NONE ||
1402 #ifdef CONFIG_ROOT_NFS
1403 (root_server_addr == NONE &&
1404 ic_servaddr == NONE &&
1405 ROOT_DEV == Root_NFS) ||
1407 ic_first_dev->next) {
1408 #ifdef IPCONFIG_DYNAMIC
1409 if (ic_dynamic() < 0) {
1413 * I don't know why, but sometimes the
1414 * eepro100 driver (at least) gets upset and
1415 * doesn't work the first time it's opened.
1416 * But then if you close it and reopen it, it
1417 * works just fine. So we need to try that at
1418 * least once before giving up.
1420 * Also, if the root will be NFS-mounted, we
1421 * have nowhere to go if DHCP fails. So we
1422 * just have to keep trying forever.
1426 #ifdef CONFIG_ROOT_NFS
1427 if (ROOT_DEV == Root_NFS) {
1428 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1434 pr_err("IP-Config: Reopening network devices...\n");
1438 /* Oh, well. At least we tried. */
1439 pr_err("IP-Config: Auto-configuration of network failed\n");
1442 #else /* !DYNAMIC */
1443 pr_err("IP-Config: Incomplete network configuration information\n");
1446 #endif /* IPCONFIG_DYNAMIC */
1448 /* Device selected manually or only one device -> use it */
1449 ic_dev = ic_first_dev;
1452 addr = root_nfs_parse_addr(root_server_path);
1453 if (root_server_addr == NONE)
1454 root_server_addr = addr;
1457 * Use defaults wherever applicable.
1459 if (ic_defaults() < 0)
1463 * Record which protocol was actually used.
1465 #ifdef IPCONFIG_DYNAMIC
1466 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1469 #ifndef IPCONFIG_SILENT
1471 * Clue in the operator.
1473 pr_info("IP-Config: Complete:\n");
1475 pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1476 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1477 &ic_myaddr, &ic_netmask, &ic_gateway);
1478 pr_info(" host=%s, domain=%s, nis-domain=%s\n",
1479 utsname()->nodename, ic_domain, utsname()->domainname);
1480 pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1481 &ic_servaddr, &root_server_addr, root_server_path);
1483 pr_cont(", mtu=%d", ic_dev_mtu);
1484 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
1485 if (ic_nameservers[i] != NONE) {
1486 pr_cont(" nameserver%u=%pI4",
1487 i, &ic_nameservers[i]);
1490 for (i++; i < CONF_NAMESERVERS_MAX; i++)
1491 if (ic_nameservers[i] != NONE)
1492 pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]);
1494 #endif /* !SILENT */
1497 * Close all network devices except the device we've
1498 * autoconfigured and set up routes.
1500 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1510 late_initcall(ip_auto_config);
1514 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1515 * command line parameter. See Documentation/filesystems/nfs/nfsroot.txt.
1517 static int __init ic_proto_name(char *name)
1519 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1522 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1525 #ifdef CONFIG_IP_PNP_DHCP
1526 else if (!strncmp(name, "dhcp", 4)) {
1529 ic_proto_enabled &= ~IC_RARP;
1530 client_id = strstr(name, "dhcp,");
1534 client_id = client_id + 5;
1535 v = strchr(client_id, ',');
1539 if (kstrtou8(client_id, 0, dhcp_client_identifier))
1540 pr_debug("DHCP: Invalid client identifier type\n");
1541 strncpy(dhcp_client_identifier + 1, v + 1, 251);
1547 #ifdef CONFIG_IP_PNP_BOOTP
1548 else if (!strcmp(name, "bootp")) {
1549 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1553 #ifdef CONFIG_IP_PNP_RARP
1554 else if (!strcmp(name, "rarp")) {
1555 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1559 #ifdef IPCONFIG_DYNAMIC
1560 else if (!strcmp(name, "both")) {
1561 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1568 static int __init ip_auto_config_setup(char *addrs)
1573 ic_set_manually = 1;
1577 * If any dhcp, bootp etc options are set, leave autoconfig on
1578 * and skip the below static IP processing.
1580 if (ic_proto_name(addrs))
1583 /* If no static IP is given, turn off autoconfig and bail. */
1585 strcmp(addrs, "off") == 0 ||
1586 strcmp(addrs, "none") == 0) {
1591 ic_nameservers_predef();
1593 /* Parse string for static IP assignment. */
1596 if ((cp = strchr(ip, ':')))
1598 if (strlen(ip) > 0) {
1599 pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1602 if ((ic_myaddr = in_aton(ip)) == ANY)
1606 if ((ic_servaddr = in_aton(ip)) == ANY)
1610 if ((ic_gateway = in_aton(ip)) == ANY)
1614 if ((ic_netmask = in_aton(ip)) == ANY)
1618 if ((dp = strchr(ip, '.'))) {
1620 strlcpy(utsname()->domainname, dp,
1621 sizeof(utsname()->domainname));
1623 strlcpy(utsname()->nodename, ip,
1624 sizeof(utsname()->nodename));
1625 ic_host_name_set = 1;
1628 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1631 if (ic_proto_name(ip) == 0 &&
1632 ic_myaddr == NONE) {
1637 if (CONF_NAMESERVERS_MAX >= 1) {
1638 ic_nameservers[0] = in_aton(ip);
1639 if (ic_nameservers[0] == ANY)
1640 ic_nameservers[0] = NONE;
1644 if (CONF_NAMESERVERS_MAX >= 2) {
1645 ic_nameservers[1] = in_aton(ip);
1646 if (ic_nameservers[1] == ANY)
1647 ic_nameservers[1] = NONE;
1658 __setup("ip=", ip_auto_config_setup);
1660 static int __init nfsaddrs_config_setup(char *addrs)
1662 return ip_auto_config_setup(addrs);
1664 __setup("nfsaddrs=", nfsaddrs_config_setup);
1666 static int __init vendor_class_identifier_setup(char *addrs)
1668 if (strlcpy(vendor_class_identifier, addrs,
1669 sizeof(vendor_class_identifier))
1670 >= sizeof(vendor_class_identifier))
1671 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1672 vendor_class_identifier);
1675 __setup("dhcpclass=", vendor_class_identifier_setup);