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
32 * NTP servers in /proc/net/ipconfig/ntp_servers
33 * -- Chris Novakovic <chris@chrisn.me.uk>, April 2018
36 #include <linux/types.h>
37 #include <linux/string.h>
38 #include <linux/kernel.h>
39 #include <linux/jiffies.h>
40 #include <linux/random.h>
41 #include <linux/init.h>
42 #include <linux/utsname.h>
45 #include <linux/inet.h>
46 #include <linux/inetdevice.h>
47 #include <linux/netdevice.h>
48 #include <linux/if_arp.h>
49 #include <linux/skbuff.h>
51 #include <linux/socket.h>
52 #include <linux/route.h>
53 #include <linux/udp.h>
54 #include <linux/proc_fs.h>
55 #include <linux/seq_file.h>
56 #include <linux/major.h>
57 #include <linux/root_dev.h>
58 #include <linux/delay.h>
59 #include <linux/nfs_fs.h>
60 #include <linux/slab.h>
61 #include <linux/export.h>
62 #include <net/net_namespace.h>
66 #include <net/ipconfig.h>
67 #include <net/route.h>
69 #include <linux/uaccess.h>
70 #include <net/checksum.h>
71 #include <asm/processor.h>
73 #if defined(CONFIG_IP_PNP_DHCP)
76 #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP)
77 #define IPCONFIG_BOOTP
79 #if defined(CONFIG_IP_PNP_RARP)
82 #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP)
83 #define IPCONFIG_DYNAMIC
86 /* Define the friendly delay before and after opening net devices */
87 #define CONF_POST_OPEN 10 /* After opening: 10 msecs */
88 #define CONF_CARRIER_TIMEOUT 120000 /* Wait for carrier timeout */
90 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
91 #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
92 #define CONF_SEND_RETRIES 6 /* Send six requests per open */
93 #define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */
94 #define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */
95 #define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */
96 #define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */
97 #define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
98 - '3' from resolv.h */
99 #define CONF_NTP_SERVERS_MAX 3 /* Maximum number of NTP servers */
101 #define NONE cpu_to_be32(INADDR_NONE)
102 #define ANY cpu_to_be32(INADDR_ANY)
105 * Public IP configuration
108 /* This is used by platforms which might be able to set the ipconfig
109 * variables using firmware environment vars. If this is set, it will
110 * ignore such firmware variables.
112 int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
114 static int ic_enable __initdata; /* IP config enabled? */
116 /* Protocol choice */
117 int ic_proto_enabled __initdata = 0
118 #ifdef IPCONFIG_BOOTP
121 #ifdef CONFIG_IP_PNP_DHCP
129 static int ic_host_name_set __initdata; /* Host name set by us? */
131 __be32 ic_myaddr = NONE; /* My IP address */
132 static __be32 ic_netmask = NONE; /* Netmask for local subnet */
133 __be32 ic_gateway = NONE; /* Gateway IP address */
135 #ifdef IPCONFIG_DYNAMIC
136 static __be32 ic_addrservaddr = NONE; /* IP Address of the IP addresses'server */
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 #if defined(CONFIG_IP_PNP_DHCP)
148 static char dhcp_client_identifier[253] __initdata;
151 /* Persistent data: */
153 #ifdef IPCONFIG_DYNAMIC
154 static int ic_proto_used; /* Protocol used, if any */
156 #define ic_proto_used 0
158 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
159 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
160 static u8 ic_domain[64]; /* DNS (not NIS) domain name */
166 /* proc_dir_entry for /proc/net/ipconfig */
167 static struct proc_dir_entry *ipconfig_dir;
169 /* Name of user-selected boot device */
170 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
172 /* Protocols supported by available interfaces */
173 static int ic_proto_have_if __initdata;
175 /* MTU for boot device */
176 static int ic_dev_mtu __initdata;
178 #ifdef IPCONFIG_DYNAMIC
179 static DEFINE_SPINLOCK(ic_recv_lock);
180 static volatile int ic_got_reply __initdata; /* Proto(s) that replied */
183 static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */
192 struct ic_device *next;
193 struct net_device *dev;
194 unsigned short flags;
199 static struct ic_device *ic_first_dev __initdata; /* List of open device */
200 static struct ic_device *ic_dev __initdata; /* Selected device */
202 static bool __init ic_is_init_dev(struct net_device *dev)
204 if (dev->flags & IFF_LOOPBACK)
206 return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
207 (!(dev->flags & IFF_LOOPBACK) &&
208 (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
209 strncmp(dev->name, "dummy", 5));
212 static int __init ic_open_devs(void)
214 struct ic_device *d, **last;
215 struct net_device *dev;
216 unsigned short oflags;
217 unsigned long start, next_msg;
219 last = &ic_first_dev;
222 /* bring loopback and DSA master network devices up first */
223 for_each_netdev(&init_net, dev) {
224 if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
226 if (dev_change_flags(dev, dev->flags | IFF_UP) < 0)
227 pr_err("IP-Config: Failed to open %s\n", dev->name);
230 for_each_netdev(&init_net, dev) {
231 if (ic_is_init_dev(dev)) {
236 pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
237 dev->name, dev->mtu);
238 if (!(dev->flags & IFF_NOARP))
240 able &= ic_proto_enabled;
241 if (ic_proto_enabled && !able)
244 if (dev_change_flags(dev, oflags | IFF_UP) < 0) {
245 pr_err("IP-Config: Failed to open %s\n",
249 if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
259 get_random_bytes(&d->xid, sizeof(__be32));
262 ic_proto_have_if |= able;
263 pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
264 dev->name, able, d->xid);
268 /* no point in waiting if we could not bring up at least one device */
272 /* wait for a carrier on at least one device */
274 next_msg = start + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
275 while (time_before(jiffies, start +
276 msecs_to_jiffies(CONF_CARRIER_TIMEOUT))) {
279 for_each_netdev(&init_net, dev)
280 if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
285 if (time_before(jiffies, next_msg))
288 elapsed = jiffies_to_msecs(jiffies - start);
289 wait = (CONF_CARRIER_TIMEOUT - elapsed + 500)/1000;
290 pr_info("Waiting up to %d more seconds for network.\n", wait);
291 next_msg = jiffies + msecs_to_jiffies(CONF_CARRIER_TIMEOUT/12);
299 if (user_dev_name[0])
300 pr_err("IP-Config: Device `%s' not found\n",
303 pr_err("IP-Config: No network devices available\n");
309 static void __init ic_close_devs(void)
311 struct ic_device *d, *next;
312 struct net_device *dev;
319 if (d != ic_dev && !netdev_uses_dsa(dev)) {
320 pr_debug("IP-Config: Downing %s\n", dev->name);
321 dev_change_flags(dev, d->flags);
329 * Interface to various network functions.
333 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
335 sin->sin_family = AF_INET;
336 sin->sin_addr.s_addr = addr;
337 sin->sin_port = port;
341 * Set up interface addresses and routes.
344 static int __init ic_setup_if(void)
347 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
350 memset(&ir, 0, sizeof(ir));
351 strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
352 set_sockaddr(sin, ic_myaddr, 0);
353 if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
354 pr_err("IP-Config: Unable to set interface address (%d)\n",
358 set_sockaddr(sin, ic_netmask, 0);
359 if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
360 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
364 set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
365 if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
366 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
370 /* Handle the case where we need non-standard MTU on the boot link (a network
371 * using jumbo frames, for instance). If we can't set the mtu, don't error
372 * out, we'll try to muddle along.
374 if (ic_dev_mtu != 0) {
376 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
377 pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
384 static int __init ic_setup_routes(void)
386 /* No need to setup device routes, only the default route... */
388 if (ic_gateway != NONE) {
392 memset(&rm, 0, sizeof(rm));
393 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
394 pr_err("IP-Config: Gateway not on directly connected network\n");
397 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
398 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
399 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
400 rm.rt_flags = RTF_UP | RTF_GATEWAY;
401 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
402 pr_err("IP-Config: Cannot add default route (%d)\n",
412 * Fill in default values for all missing parameters.
415 static int __init ic_defaults(void)
418 * At this point we have no userspace running so need not
419 * claim locks on system_utsname
422 if (!ic_host_name_set)
423 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
425 if (root_server_addr == NONE)
426 root_server_addr = ic_servaddr;
428 if (ic_netmask == NONE) {
429 if (IN_CLASSA(ntohl(ic_myaddr)))
430 ic_netmask = htonl(IN_CLASSA_NET);
431 else if (IN_CLASSB(ntohl(ic_myaddr)))
432 ic_netmask = htonl(IN_CLASSB_NET);
433 else if (IN_CLASSC(ntohl(ic_myaddr)))
434 ic_netmask = htonl(IN_CLASSC_NET);
436 pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
440 pr_notice("IP-Config: Guessing netmask %pI4\n",
453 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
455 static struct packet_type rarp_packet_type __initdata = {
456 .type = cpu_to_be16(ETH_P_RARP),
457 .func = ic_rarp_recv,
460 static inline void __init ic_rarp_init(void)
462 dev_add_pack(&rarp_packet_type);
465 static inline void __init ic_rarp_cleanup(void)
467 dev_remove_pack(&rarp_packet_type);
471 * Process received RARP packet.
474 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
477 unsigned char *rarp_ptr;
479 unsigned char *tha; /* t for "target" */
482 if (!net_eq(dev_net(dev), &init_net))
485 skb = skb_share_check(skb, GFP_ATOMIC);
489 if (!pskb_may_pull(skb, sizeof(struct arphdr)))
492 /* Basic sanity checks can be done without the lock. */
493 rarp = (struct arphdr *)skb_transport_header(skb);
495 /* If this test doesn't pass, it's not IP, or we should
498 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
501 /* If it's not a RARP reply, delete it. */
502 if (rarp->ar_op != htons(ARPOP_RREPLY))
505 /* If it's not Ethernet, delete it. */
506 if (rarp->ar_pro != htons(ETH_P_IP))
509 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
512 /* OK, it is all there and looks valid, process... */
513 rarp = (struct arphdr *)skb_transport_header(skb);
514 rarp_ptr = (unsigned char *) (rarp + 1);
516 /* One reply at a time, please. */
517 spin_lock(&ic_recv_lock);
519 /* If we already have a reply, just drop the packet */
523 /* Find the ic_device that the packet arrived on */
525 while (d && d->dev != dev)
528 goto drop_unlock; /* should never happen */
530 /* Extract variable-width fields */
531 rarp_ptr += dev->addr_len;
532 memcpy(&sip, rarp_ptr, 4);
535 rarp_ptr += dev->addr_len;
536 memcpy(&tip, rarp_ptr, 4);
538 /* Discard packets which are not meant for us. */
539 if (memcmp(tha, dev->dev_addr, dev->addr_len))
542 /* Discard packets which are not from specified server. */
543 if (ic_servaddr != NONE && ic_servaddr != sip)
546 /* We have a winner! */
548 if (ic_myaddr == NONE)
551 ic_addrservaddr = sip;
552 ic_got_reply = IC_RARP;
555 /* Show's over. Nothing to see here. */
556 spin_unlock(&ic_recv_lock);
559 /* Throw the packet out. */
566 * Send RARP request packet over a single interface.
568 static void __init ic_rarp_send_if(struct ic_device *d)
570 struct net_device *dev = d->dev;
571 arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
572 dev->dev_addr, dev->dev_addr);
577 * Predefine Nameservers
579 static inline void __init ic_nameservers_predef(void)
583 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
584 ic_nameservers[i] = NONE;
587 /* Predefine NTP servers */
588 static inline void __init ic_ntp_servers_predef(void)
592 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
593 ic_ntp_servers[i] = NONE;
597 * DHCP/BOOTP support.
600 #ifdef IPCONFIG_BOOTP
602 struct bootp_pkt { /* BOOTP packet format */
603 struct iphdr iph; /* IP header */
604 struct udphdr udph; /* UDP header */
605 u8 op; /* 1=request, 2=reply */
606 u8 htype; /* HW address type */
607 u8 hlen; /* HW address length */
608 u8 hops; /* Used only by gateways */
609 __be32 xid; /* Transaction ID */
610 __be16 secs; /* Seconds since we started */
611 __be16 flags; /* Just what it says */
612 __be32 client_ip; /* Client's IP address if known */
613 __be32 your_ip; /* Assigned IP address */
614 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
615 __be32 relay_ip; /* IP address of BOOTP relay */
616 u8 hw_addr[16]; /* Client's HW address */
617 u8 serv_name[64]; /* Server host name */
618 u8 boot_file[128]; /* Name of boot file */
619 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
623 #define BOOTP_REQUEST 1
624 #define BOOTP_REPLY 2
626 /* DHCP message types */
627 #define DHCPDISCOVER 1
629 #define DHCPREQUEST 3
630 #define DHCPDECLINE 4
633 #define DHCPRELEASE 7
636 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
638 static struct packet_type bootp_packet_type __initdata = {
639 .type = cpu_to_be16(ETH_P_IP),
640 .func = ic_bootp_recv,
644 * Initialize DHCP/BOOTP extension fields in the request.
647 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
652 ic_dhcp_init_options(u8 *options, struct ic_device *d)
654 u8 mt = ((ic_servaddr == NONE)
655 ? DHCPDISCOVER : DHCPREQUEST);
659 pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
661 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
664 *e++ = 53; /* DHCP message type */
668 if (mt == DHCPREQUEST) {
669 *e++ = 54; /* Server ID (IP address) */
671 memcpy(e, &ic_servaddr, 4);
674 *e++ = 50; /* Requested IP address */
676 memcpy(e, &ic_myaddr, 4);
682 static const u8 ic_req_params[] = {
684 3, /* Default gateway */
687 15, /* Domain name */
690 40, /* NIS domain name */
691 42, /* NTP servers */
694 *e++ = 55; /* Parameter request list */
695 *e++ = sizeof(ic_req_params);
696 memcpy(e, ic_req_params, sizeof(ic_req_params));
697 e += sizeof(ic_req_params);
699 if (ic_host_name_set) {
700 *e++ = 12; /* host-name */
701 len = strlen(utsname()->nodename);
703 memcpy(e, utsname()->nodename, len);
706 if (*vendor_class_identifier) {
707 pr_info("DHCP: sending class identifier \"%s\"\n",
708 vendor_class_identifier);
709 *e++ = 60; /* Class-identifier */
710 len = strlen(vendor_class_identifier);
712 memcpy(e, vendor_class_identifier, len);
715 len = strlen(dhcp_client_identifier + 1);
716 /* the minimum length of identifier is 2, include 1 byte type,
717 * and can not be larger than the length of options
719 if (len >= 1 && len < 312 - (e - options) - 1) {
722 memcpy(e, dhcp_client_identifier, len + 1);
727 *e++ = 255; /* End of the list */
730 #endif /* IPCONFIG_DHCP */
732 static void __init ic_bootp_init_ext(u8 *e)
734 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
736 *e++ = 1; /* Subnet mask request */
739 *e++ = 3; /* Default gateway request */
742 #if CONF_NAMESERVERS_MAX > 0
743 *e++ = 6; /* (DNS) name server request */
744 *e++ = 4 * CONF_NAMESERVERS_MAX;
745 e += 4 * CONF_NAMESERVERS_MAX;
747 *e++ = 12; /* Host name request */
750 *e++ = 40; /* NIS Domain name request */
753 *e++ = 17; /* Boot path */
757 *e++ = 57; /* set extension buffer size for reply */
759 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
762 *e++ = 255; /* End of the list */
767 * Initialize the DHCP/BOOTP mechanism.
769 static inline void __init ic_bootp_init(void)
771 /* Re-initialise all name servers and NTP servers to NONE, in case any
772 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
773 * any IP addresses specified there will already have been decoded but
774 * are no longer needed
776 ic_nameservers_predef();
777 ic_ntp_servers_predef();
779 dev_add_pack(&bootp_packet_type);
784 * DHCP/BOOTP cleanup.
786 static inline void __init ic_bootp_cleanup(void)
788 dev_remove_pack(&bootp_packet_type);
793 * Send DHCP/BOOTP request to single interface.
795 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
797 struct net_device *dev = d->dev;
801 int hlen = LL_RESERVED_SPACE(dev);
802 int tlen = dev->needed_tailroom;
804 /* Allocate packet */
805 skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
809 skb_reserve(skb, hlen);
810 b = skb_put_zero(skb, sizeof(struct bootp_pkt));
812 /* Construct IP header */
813 skb_reset_network_header(skb);
817 h->tot_len = htons(sizeof(struct bootp_pkt));
818 h->frag_off = htons(IP_DF);
820 h->protocol = IPPROTO_UDP;
821 h->daddr = htonl(INADDR_BROADCAST);
822 h->check = ip_fast_csum((unsigned char *) h, h->ihl);
824 /* Construct UDP header */
825 b->udph.source = htons(68);
826 b->udph.dest = htons(67);
827 b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
828 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
830 /* Construct DHCP/BOOTP header */
831 b->op = BOOTP_REQUEST;
832 if (dev->type < 256) /* check for false types */
833 b->htype = dev->type;
834 else if (dev->type == ARPHRD_FDDI)
835 b->htype = ARPHRD_ETHER;
837 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
839 b->htype = dev->type; /* can cause undefined behavior */
842 /* server_ip and your_ip address are both already zero per RFC2131 */
843 b->hlen = dev->addr_len;
844 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
845 b->secs = htons(jiffies_diff / HZ);
848 /* add DHCP options or BOOTP extensions */
850 if (ic_proto_enabled & IC_USE_DHCP)
851 ic_dhcp_init_options(b->exten, d);
854 ic_bootp_init_ext(b->exten);
856 /* Chain packet down the line... */
858 skb->protocol = htons(ETH_P_IP);
859 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
860 dev->broadcast, dev->dev_addr, skb->len) < 0) {
866 if (dev_queue_xmit(skb) < 0)
872 * Copy BOOTP-supplied string if not already set.
874 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
880 memcpy(dest, src, len);
887 * Process BOOTP extensions.
889 static void __init ic_do_bootp_ext(u8 *ext)
897 pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
898 for (c=ext+2; c<ext+2+ext[1]; c++)
899 pr_debug(" %02x", *c);
903 case 1: /* Subnet mask */
904 if (ic_netmask == NONE)
905 memcpy(&ic_netmask, ext+1, 4);
907 case 3: /* Default gateway */
908 if (ic_gateway == NONE)
909 memcpy(&ic_gateway, ext+1, 4);
911 case 6: /* DNS server */
913 if (servers > CONF_NAMESERVERS_MAX)
914 servers = CONF_NAMESERVERS_MAX;
915 for (i = 0; i < servers; i++) {
916 if (ic_nameservers[i] == NONE)
917 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
920 case 12: /* Host name */
921 ic_bootp_string(utsname()->nodename, ext+1, *ext,
923 ic_host_name_set = 1;
925 case 15: /* Domain name (DNS) */
926 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
928 case 17: /* Root path */
929 if (!root_server_path[0])
930 ic_bootp_string(root_server_path, ext+1, *ext,
931 sizeof(root_server_path));
933 case 26: /* Interface MTU */
934 memcpy(&mtu, ext+1, sizeof(mtu));
935 ic_dev_mtu = ntohs(mtu);
937 case 40: /* NIS Domain name (_not_ DNS) */
938 ic_bootp_string(utsname()->domainname, ext+1, *ext,
941 case 42: /* NTP servers */
943 if (servers > CONF_NTP_SERVERS_MAX)
944 servers = CONF_NTP_SERVERS_MAX;
945 for (i = 0; i < servers; i++) {
946 if (ic_ntp_servers[i] == NONE)
947 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
955 * Receive BOOTP reply.
957 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
964 if (!net_eq(dev_net(dev), &init_net))
967 /* Perform verifications before taking the lock. */
968 if (skb->pkt_type == PACKET_OTHERHOST)
971 skb = skb_share_check(skb, GFP_ATOMIC);
975 if (!pskb_may_pull(skb,
976 sizeof(struct iphdr) +
977 sizeof(struct udphdr)))
980 b = (struct bootp_pkt *)skb_network_header(skb);
983 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
986 /* Fragments are not supported */
987 if (ip_is_fragment(h)) {
988 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
992 if (skb->len < ntohs(h->tot_len))
995 if (ip_fast_csum((char *) h, h->ihl))
998 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1001 if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1004 len = ntohs(b->udph.len) - sizeof(struct udphdr);
1005 ext_len = len - (sizeof(*b) -
1006 sizeof(struct iphdr) -
1007 sizeof(struct udphdr) -
1012 /* Ok the front looks good, make sure we can get at the rest. */
1013 if (!pskb_may_pull(skb, skb->len))
1016 b = (struct bootp_pkt *)skb_network_header(skb);
1019 /* One reply at a time, please. */
1020 spin_lock(&ic_recv_lock);
1022 /* If we already have a reply, just drop the packet */
1026 /* Find the ic_device that the packet arrived on */
1028 while (d && d->dev != dev)
1031 goto drop_unlock; /* should never happen */
1033 /* Is it a reply to our BOOTP request? */
1034 if (b->op != BOOTP_REPLY ||
1036 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1037 d->dev->name, b->op, b->xid);
1041 /* Parse extensions */
1043 !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1044 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1047 #ifdef IPCONFIG_DHCP
1048 if (ic_proto_enabled & IC_USE_DHCP) {
1049 __be32 server_id = NONE;
1053 while (ext < end && *ext != 0xff) {
1055 if (*opt == 0) /* Padding */
1061 case 53: /* Message type */
1065 case 54: /* Server ID (IP address) */
1067 memcpy(&server_id, opt + 2, 4);
1072 pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1076 /* While in the process of accepting one offer,
1077 * ignore all others.
1079 if (ic_myaddr != NONE)
1082 /* Let's accept that offer. */
1083 ic_myaddr = b->your_ip;
1084 ic_servaddr = server_id;
1085 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1086 &ic_myaddr, &b->iph.saddr);
1087 /* The DHCP indicated server address takes
1088 * precedence over the bootp header one if
1089 * they are different.
1091 if ((server_id != NONE) &&
1092 (b->server_ip != server_id))
1093 b->server_ip = ic_servaddr;
1097 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1104 /* Urque. Forget it*/
1110 ic_dhcp_msgtype = mt;
1113 #endif /* IPCONFIG_DHCP */
1116 while (ext < end && *ext != 0xff) {
1118 if (*opt == 0) /* Padding */
1122 ic_do_bootp_ext(opt);
1126 /* We have a winner! */
1128 ic_myaddr = b->your_ip;
1129 ic_servaddr = b->server_ip;
1130 ic_addrservaddr = b->iph.saddr;
1131 if (ic_gateway == NONE && b->relay_ip)
1132 ic_gateway = b->relay_ip;
1133 if (ic_nameservers[0] == NONE)
1134 ic_nameservers[0] = ic_servaddr;
1135 ic_got_reply = IC_BOOTP;
1138 /* Show's over. Nothing to see here. */
1139 spin_unlock(&ic_recv_lock);
1142 /* Throw the packet out. */
1153 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1156 #ifdef IPCONFIG_DYNAMIC
1158 static int __init ic_dynamic(void)
1161 struct ic_device *d;
1162 unsigned long start_jiffies, timeout, jiff;
1163 int do_bootp = ic_proto_have_if & IC_BOOTP;
1164 int do_rarp = ic_proto_have_if & IC_RARP;
1167 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1168 * This routine gets only called when some pieces of information
1169 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1171 if (!ic_proto_enabled) {
1172 pr_err("IP-Config: Incomplete network configuration information\n");
1176 #ifdef IPCONFIG_BOOTP
1177 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1178 pr_err("DHCP/BOOTP: No suitable device found\n");
1180 #ifdef IPCONFIG_RARP
1181 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1182 pr_err("RARP: No suitable device found\n");
1185 if (!ic_proto_have_if)
1186 /* Error message already printed */
1192 #ifdef IPCONFIG_BOOTP
1196 #ifdef IPCONFIG_RARP
1202 * Send requests and wait, until we get an answer. This loop
1203 * seems to be a terrible waste of CPU time, but actually there is
1204 * only one process running at all, so we don't need to use any
1205 * scheduler functions.
1206 * [Actually we could now, but the nothing else running note still
1209 pr_notice("Sending %s%s%s requests .",
1211 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1212 (do_bootp && do_rarp) ? " and " : "",
1213 do_rarp ? "RARP" : "");
1215 start_jiffies = jiffies;
1217 retries = CONF_SEND_RETRIES;
1218 get_random_bytes(&timeout, sizeof(timeout));
1219 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1221 #ifdef IPCONFIG_BOOTP
1222 if (do_bootp && (d->able & IC_BOOTP))
1223 ic_bootp_send_if(d, jiffies - start_jiffies);
1225 #ifdef IPCONFIG_RARP
1226 if (do_rarp && (d->able & IC_RARP))
1231 jiff = jiffies + timeout;
1232 while (time_before(jiffies, jiff) && !ic_got_reply)
1233 schedule_timeout_uninterruptible(1);
1235 #ifdef IPCONFIG_DHCP
1236 /* DHCP isn't done until we get a DHCPACK. */
1237 if ((ic_got_reply & IC_BOOTP) &&
1238 (ic_proto_enabled & IC_USE_DHCP) &&
1239 ic_dhcp_msgtype != DHCPACK) {
1241 /* continue on device that got the reply */
1246 #endif /* IPCONFIG_DHCP */
1257 pr_cont(" timed out!\n");
1263 timeout = timeout CONF_TIMEOUT_MULT;
1264 if (timeout > CONF_TIMEOUT_MAX)
1265 timeout = CONF_TIMEOUT_MAX;
1270 #ifdef IPCONFIG_BOOTP
1274 #ifdef IPCONFIG_RARP
1279 if (!ic_got_reply) {
1284 pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1285 ((ic_got_reply & IC_RARP) ? "RARP"
1286 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1287 &ic_addrservaddr, &ic_myaddr);
1292 #endif /* IPCONFIG_DYNAMIC */
1294 #ifdef CONFIG_PROC_FS
1297 static int pnp_seq_show(struct seq_file *seq, void *v)
1301 if (ic_proto_used & IC_PROTO)
1302 seq_printf(seq, "#PROTO: %s\n",
1303 (ic_proto_used & IC_RARP) ? "RARP"
1304 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1306 seq_puts(seq, "#MANUAL\n");
1310 "domain %s\n", ic_domain);
1311 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1312 if (ic_nameservers[i] != NONE)
1313 seq_printf(seq, "nameserver %pI4\n",
1314 &ic_nameservers[i]);
1316 if (ic_servaddr != NONE)
1317 seq_printf(seq, "bootserver %pI4\n",
1322 static int pnp_seq_open(struct inode *indoe, struct file *file)
1324 return single_open(file, pnp_seq_show, NULL);
1327 static const struct file_operations pnp_seq_fops = {
1328 .open = pnp_seq_open,
1330 .llseek = seq_lseek,
1331 .release = single_release,
1334 /* Create the /proc/net/ipconfig directory */
1335 static int __init ipconfig_proc_net_init(void)
1337 ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1344 /* Create a new file under /proc/net/ipconfig */
1345 static int ipconfig_proc_net_create(const char *name,
1346 const struct file_operations *fops)
1349 struct proc_dir_entry *p;
1354 pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1358 p = proc_create(pname, 0444, init_net.proc_net, fops);
1366 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1367 static int ntp_servers_seq_show(struct seq_file *seq, void *v)
1371 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1372 if (ic_ntp_servers[i] != NONE)
1373 seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1378 static int ntp_servers_seq_open(struct inode *inode, struct file *file)
1380 return single_open(file, ntp_servers_seq_show, NULL);
1383 static const struct file_operations ntp_servers_seq_fops = {
1384 .open = ntp_servers_seq_open,
1386 .llseek = seq_lseek,
1387 .release = single_release,
1389 #endif /* CONFIG_PROC_FS */
1392 * Extract IP address from the parameter string if needed. Note that we
1393 * need to have root_server_addr set _before_ IPConfig gets called as it
1396 __be32 __init root_nfs_parse_addr(char *name)
1403 while (octets < 4) {
1404 while (*cp >= '0' && *cp <= '9')
1406 if (cp == cq || cp - cq > 3)
1408 if (*cp == '.' || octets == 3)
1414 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1417 addr = in_aton(name);
1418 memmove(name, cp, strlen(cp) + 1);
1425 #define DEVICE_WAIT_MAX 12 /* 12 seconds */
1427 static int __init wait_for_devices(void)
1431 for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1432 struct net_device *dev;
1436 for_each_netdev(&init_net, dev) {
1437 if (ic_is_init_dev(dev)) {
1451 * IP Autoconfig dispatcher.
1454 static int __init ip_auto_config(void)
1457 #ifdef IPCONFIG_DYNAMIC
1458 int retries = CONF_OPEN_RETRIES;
1463 /* Initialise all name servers and NTP servers to NONE (but only if the
1464 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1465 * otherwise we'll overwrite the IP addresses specified there)
1467 if (ic_set_manually == 0) {
1468 ic_nameservers_predef();
1469 ic_ntp_servers_predef();
1472 #ifdef CONFIG_PROC_FS
1473 proc_create("pnp", 0444, init_net.proc_net, &pnp_seq_fops);
1475 if (ipconfig_proc_net_init() == 0)
1476 ipconfig_proc_net_create("ntp_servers", &ntp_servers_seq_fops);
1477 #endif /* CONFIG_PROC_FS */
1482 pr_debug("IP-Config: Entered.\n");
1483 #ifdef IPCONFIG_DYNAMIC
1486 /* Wait for devices to appear */
1487 err = wait_for_devices();
1491 /* Setup all network devices */
1492 err = ic_open_devs();
1496 /* Give drivers a chance to settle */
1497 msleep(CONF_POST_OPEN);
1500 * If the config information is insufficient (e.g., our IP address or
1501 * IP address of the boot server is missing or we have multiple network
1502 * interfaces and no default was set), use BOOTP or RARP to get the
1505 if (ic_myaddr == NONE ||
1506 #ifdef CONFIG_ROOT_NFS
1507 (root_server_addr == NONE &&
1508 ic_servaddr == NONE &&
1509 ROOT_DEV == Root_NFS) ||
1511 ic_first_dev->next) {
1512 #ifdef IPCONFIG_DYNAMIC
1513 if (ic_dynamic() < 0) {
1517 * I don't know why, but sometimes the
1518 * eepro100 driver (at least) gets upset and
1519 * doesn't work the first time it's opened.
1520 * But then if you close it and reopen it, it
1521 * works just fine. So we need to try that at
1522 * least once before giving up.
1524 * Also, if the root will be NFS-mounted, we
1525 * have nowhere to go if DHCP fails. So we
1526 * just have to keep trying forever.
1530 #ifdef CONFIG_ROOT_NFS
1531 if (ROOT_DEV == Root_NFS) {
1532 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1538 pr_err("IP-Config: Reopening network devices...\n");
1542 /* Oh, well. At least we tried. */
1543 pr_err("IP-Config: Auto-configuration of network failed\n");
1546 #else /* !DYNAMIC */
1547 pr_err("IP-Config: Incomplete network configuration information\n");
1550 #endif /* IPCONFIG_DYNAMIC */
1552 /* Device selected manually or only one device -> use it */
1553 ic_dev = ic_first_dev;
1556 addr = root_nfs_parse_addr(root_server_path);
1557 if (root_server_addr == NONE)
1558 root_server_addr = addr;
1561 * Use defaults wherever applicable.
1563 if (ic_defaults() < 0)
1567 * Record which protocol was actually used.
1569 #ifdef IPCONFIG_DYNAMIC
1570 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1573 #ifndef IPCONFIG_SILENT
1575 * Clue in the operator.
1577 pr_info("IP-Config: Complete:\n");
1579 pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1580 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1581 &ic_myaddr, &ic_netmask, &ic_gateway);
1582 pr_info(" host=%s, domain=%s, nis-domain=%s\n",
1583 utsname()->nodename, ic_domain, utsname()->domainname);
1584 pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1585 &ic_servaddr, &root_server_addr, root_server_path);
1587 pr_cont(", mtu=%d", ic_dev_mtu);
1588 /* Name servers (if any): */
1589 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1590 if (ic_nameservers[i] != NONE) {
1592 pr_info(" nameserver%u=%pI4",
1593 i, &ic_nameservers[i]);
1595 pr_cont(", nameserver%u=%pI4",
1596 i, &ic_nameservers[i]);
1598 if (i + 1 == CONF_NAMESERVERS_MAX)
1601 /* NTP servers (if any): */
1602 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1603 if (ic_ntp_servers[i] != NONE) {
1605 pr_info(" ntpserver%u=%pI4",
1606 i, &ic_ntp_servers[i]);
1608 pr_cont(", ntpserver%u=%pI4",
1609 i, &ic_ntp_servers[i]);
1611 if (i + 1 == CONF_NTP_SERVERS_MAX)
1614 #endif /* !SILENT */
1617 * Close all network devices except the device we've
1618 * autoconfigured and set up routes.
1620 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1630 late_initcall(ip_auto_config);
1634 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1635 * command line parameter. See Documentation/filesystems/nfs/nfsroot.txt.
1637 static int __init ic_proto_name(char *name)
1639 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1642 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1645 #ifdef CONFIG_IP_PNP_DHCP
1646 else if (!strncmp(name, "dhcp", 4)) {
1649 ic_proto_enabled &= ~IC_RARP;
1650 client_id = strstr(name, "dhcp,");
1654 client_id = client_id + 5;
1655 v = strchr(client_id, ',');
1659 if (kstrtou8(client_id, 0, dhcp_client_identifier))
1660 pr_debug("DHCP: Invalid client identifier type\n");
1661 strncpy(dhcp_client_identifier + 1, v + 1, 251);
1667 #ifdef CONFIG_IP_PNP_BOOTP
1668 else if (!strcmp(name, "bootp")) {
1669 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1673 #ifdef CONFIG_IP_PNP_RARP
1674 else if (!strcmp(name, "rarp")) {
1675 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1679 #ifdef IPCONFIG_DYNAMIC
1680 else if (!strcmp(name, "both")) {
1681 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1688 static int __init ip_auto_config_setup(char *addrs)
1693 ic_set_manually = 1;
1697 * If any dhcp, bootp etc options are set, leave autoconfig on
1698 * and skip the below static IP processing.
1700 if (ic_proto_name(addrs))
1703 /* If no static IP is given, turn off autoconfig and bail. */
1705 strcmp(addrs, "off") == 0 ||
1706 strcmp(addrs, "none") == 0) {
1711 /* Initialise all name servers and NTP servers to NONE */
1712 ic_nameservers_predef();
1713 ic_ntp_servers_predef();
1715 /* Parse string for static IP assignment. */
1718 if ((cp = strchr(ip, ':')))
1720 if (strlen(ip) > 0) {
1721 pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1724 if ((ic_myaddr = in_aton(ip)) == ANY)
1728 if ((ic_servaddr = in_aton(ip)) == ANY)
1732 if ((ic_gateway = in_aton(ip)) == ANY)
1736 if ((ic_netmask = in_aton(ip)) == ANY)
1740 if ((dp = strchr(ip, '.'))) {
1742 strlcpy(utsname()->domainname, dp,
1743 sizeof(utsname()->domainname));
1745 strlcpy(utsname()->nodename, ip,
1746 sizeof(utsname()->nodename));
1747 ic_host_name_set = 1;
1750 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1753 if (ic_proto_name(ip) == 0 &&
1754 ic_myaddr == NONE) {
1759 if (CONF_NAMESERVERS_MAX >= 1) {
1760 ic_nameservers[0] = in_aton(ip);
1761 if (ic_nameservers[0] == ANY)
1762 ic_nameservers[0] = NONE;
1766 if (CONF_NAMESERVERS_MAX >= 2) {
1767 ic_nameservers[1] = in_aton(ip);
1768 if (ic_nameservers[1] == ANY)
1769 ic_nameservers[1] = NONE;
1773 if (CONF_NTP_SERVERS_MAX >= 1) {
1774 ic_ntp_servers[0] = in_aton(ip);
1775 if (ic_ntp_servers[0] == ANY)
1776 ic_ntp_servers[0] = NONE;
1787 __setup("ip=", ip_auto_config_setup);
1789 static int __init nfsaddrs_config_setup(char *addrs)
1791 return ip_auto_config_setup(addrs);
1793 __setup("nfsaddrs=", nfsaddrs_config_setup);
1795 static int __init vendor_class_identifier_setup(char *addrs)
1797 if (strlcpy(vendor_class_identifier, addrs,
1798 sizeof(vendor_class_identifier))
1799 >= sizeof(vendor_class_identifier))
1800 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1801 vendor_class_identifier);
1804 __setup("dhcpclass=", vendor_class_identifier_setup);