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 */
89 /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */
90 #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */
91 #define CONF_SEND_RETRIES 6 /* Send six requests per open */
92 #define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */
93 #define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */
94 #define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */
95 #define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */
96 #define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers
97 - '3' from resolv.h */
98 #define CONF_NTP_SERVERS_MAX 3 /* Maximum number of NTP servers */
100 #define NONE cpu_to_be32(INADDR_NONE)
101 #define ANY cpu_to_be32(INADDR_ANY)
103 /* Wait for carrier timeout default in seconds */
104 static unsigned int carrier_timeout = 120;
107 * Public IP configuration
110 /* This is used by platforms which might be able to set the ipconfig
111 * variables using firmware environment vars. If this is set, it will
112 * ignore such firmware variables.
114 int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */
116 static int ic_enable __initdata; /* IP config enabled? */
118 /* Protocol choice */
119 int ic_proto_enabled __initdata = 0
120 #ifdef IPCONFIG_BOOTP
123 #ifdef CONFIG_IP_PNP_DHCP
131 static int ic_host_name_set __initdata; /* Host name set by us? */
133 __be32 ic_myaddr = NONE; /* My IP address */
134 static __be32 ic_netmask = NONE; /* Netmask for local subnet */
135 __be32 ic_gateway = NONE; /* Gateway IP address */
137 #ifdef IPCONFIG_DYNAMIC
138 static __be32 ic_addrservaddr = NONE; /* IP Address of the IP addresses'server */
141 __be32 ic_servaddr = NONE; /* Boot server IP address */
143 __be32 root_server_addr = NONE; /* Address of NFS server */
144 u8 root_server_path[256] = { 0, }; /* Path to mount as root */
146 /* vendor class identifier */
147 static char vendor_class_identifier[253] __initdata;
149 #if defined(CONFIG_IP_PNP_DHCP)
150 static char dhcp_client_identifier[253] __initdata;
153 /* Persistent data: */
155 #ifdef IPCONFIG_DYNAMIC
156 static int ic_proto_used; /* Protocol used, if any */
158 #define ic_proto_used 0
160 static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */
161 static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP server IP addresses */
162 static u8 ic_domain[64]; /* DNS (not NIS) domain name */
168 /* Name of user-selected boot device */
169 static char user_dev_name[IFNAMSIZ] __initdata = { 0, };
171 /* Protocols supported by available interfaces */
172 static int ic_proto_have_if __initdata;
174 /* MTU for boot device */
175 static int ic_dev_mtu __initdata;
177 #ifdef IPCONFIG_DYNAMIC
178 static DEFINE_SPINLOCK(ic_recv_lock);
179 static volatile int ic_got_reply __initdata; /* Proto(s) that replied */
182 static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */
191 struct ic_device *next;
192 struct net_device *dev;
193 unsigned short flags;
198 static struct ic_device *ic_first_dev __initdata; /* List of open device */
199 static struct ic_device *ic_dev __initdata; /* Selected device */
201 static bool __init ic_is_init_dev(struct net_device *dev)
203 if (dev->flags & IFF_LOOPBACK)
205 return user_dev_name[0] ? !strcmp(dev->name, user_dev_name) :
206 (!(dev->flags & IFF_LOOPBACK) &&
207 (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) &&
208 strncmp(dev->name, "dummy", 5));
211 static int __init ic_open_devs(void)
213 struct ic_device *d, **last;
214 struct net_device *dev;
215 unsigned short oflags;
216 unsigned long start, next_msg;
218 last = &ic_first_dev;
221 /* bring loopback and DSA master network devices up first */
222 for_each_netdev(&init_net, dev) {
223 if (!(dev->flags & IFF_LOOPBACK) && !netdev_uses_dsa(dev))
225 if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0)
226 pr_err("IP-Config: Failed to open %s\n", dev->name);
229 for_each_netdev(&init_net, dev) {
230 if (ic_is_init_dev(dev)) {
235 pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n",
236 dev->name, dev->mtu);
237 if (!(dev->flags & IFF_NOARP))
239 able &= ic_proto_enabled;
240 if (ic_proto_enabled && !able)
243 if (dev_change_flags(dev, oflags | IFF_UP, NULL) < 0) {
244 pr_err("IP-Config: Failed to open %s\n",
248 if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) {
258 get_random_bytes(&d->xid, sizeof(__be32));
261 ic_proto_have_if |= able;
262 pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n",
263 dev->name, able, d->xid);
267 /* no point in waiting if we could not bring up at least one device */
271 /* wait for a carrier on at least one device */
273 next_msg = start + msecs_to_jiffies(20000);
274 while (time_before(jiffies, start +
275 msecs_to_jiffies(carrier_timeout * 1000))) {
278 for_each_netdev(&init_net, dev)
279 if (ic_is_init_dev(dev) && netif_carrier_ok(dev))
284 if (time_before(jiffies, next_msg))
287 elapsed = jiffies_to_msecs(jiffies - start);
288 wait = (carrier_timeout * 1000 - elapsed + 500) / 1000;
289 pr_info("Waiting up to %d more seconds for network.\n", wait);
290 next_msg = jiffies + msecs_to_jiffies(20000);
298 if (user_dev_name[0])
299 pr_err("IP-Config: Device `%s' not found\n",
302 pr_err("IP-Config: No network devices available\n");
308 static void __init ic_close_devs(void)
310 struct ic_device *d, *next;
311 struct net_device *dev;
318 if (d != ic_dev && !netdev_uses_dsa(dev)) {
319 pr_debug("IP-Config: Downing %s\n", dev->name);
320 dev_change_flags(dev, d->flags, NULL);
328 * Interface to various network functions.
332 set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port)
334 sin->sin_family = AF_INET;
335 sin->sin_addr.s_addr = addr;
336 sin->sin_port = port;
340 * Set up interface addresses and routes.
343 static int __init ic_setup_if(void)
346 struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr;
349 memset(&ir, 0, sizeof(ir));
350 strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->dev->name);
351 set_sockaddr(sin, ic_myaddr, 0);
352 if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) {
353 pr_err("IP-Config: Unable to set interface address (%d)\n",
357 set_sockaddr(sin, ic_netmask, 0);
358 if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) {
359 pr_err("IP-Config: Unable to set interface netmask (%d)\n",
363 set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0);
364 if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) {
365 pr_err("IP-Config: Unable to set interface broadcast address (%d)\n",
369 /* Handle the case where we need non-standard MTU on the boot link (a network
370 * using jumbo frames, for instance). If we can't set the mtu, don't error
371 * out, we'll try to muddle along.
373 if (ic_dev_mtu != 0) {
375 if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0)
376 pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n",
383 static int __init ic_setup_routes(void)
385 /* No need to setup device routes, only the default route... */
387 if (ic_gateway != NONE) {
391 memset(&rm, 0, sizeof(rm));
392 if ((ic_gateway ^ ic_myaddr) & ic_netmask) {
393 pr_err("IP-Config: Gateway not on directly connected network\n");
396 set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0);
397 set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0);
398 set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0);
399 rm.rt_flags = RTF_UP | RTF_GATEWAY;
400 if ((err = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) {
401 pr_err("IP-Config: Cannot add default route (%d)\n",
411 * Fill in default values for all missing parameters.
414 static int __init ic_defaults(void)
417 * At this point we have no userspace running so need not
418 * claim locks on system_utsname
421 if (!ic_host_name_set)
422 sprintf(init_utsname()->nodename, "%pI4", &ic_myaddr);
424 if (root_server_addr == NONE)
425 root_server_addr = ic_servaddr;
427 if (ic_netmask == NONE) {
428 if (IN_CLASSA(ntohl(ic_myaddr)))
429 ic_netmask = htonl(IN_CLASSA_NET);
430 else if (IN_CLASSB(ntohl(ic_myaddr)))
431 ic_netmask = htonl(IN_CLASSB_NET);
432 else if (IN_CLASSC(ntohl(ic_myaddr)))
433 ic_netmask = htonl(IN_CLASSC_NET);
434 else if (IN_CLASSE(ntohl(ic_myaddr)))
435 ic_netmask = htonl(IN_CLASSE_NET);
437 pr_err("IP-Config: Unable to guess netmask for address %pI4\n",
441 pr_notice("IP-Config: Guessing netmask %pI4\n",
454 static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
456 static struct packet_type rarp_packet_type __initdata = {
457 .type = cpu_to_be16(ETH_P_RARP),
458 .func = ic_rarp_recv,
461 static inline void __init ic_rarp_init(void)
463 dev_add_pack(&rarp_packet_type);
466 static inline void __init ic_rarp_cleanup(void)
468 dev_remove_pack(&rarp_packet_type);
472 * Process received RARP packet.
475 ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
478 unsigned char *rarp_ptr;
480 unsigned char *tha; /* t for "target" */
483 if (!net_eq(dev_net(dev), &init_net))
486 skb = skb_share_check(skb, GFP_ATOMIC);
490 if (!pskb_may_pull(skb, sizeof(struct arphdr)))
493 /* Basic sanity checks can be done without the lock. */
494 rarp = (struct arphdr *)skb_transport_header(skb);
496 /* If this test doesn't pass, it's not IP, or we should
499 if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd))
502 /* If it's not a RARP reply, delete it. */
503 if (rarp->ar_op != htons(ARPOP_RREPLY))
506 /* If it's not Ethernet, delete it. */
507 if (rarp->ar_pro != htons(ETH_P_IP))
510 if (!pskb_may_pull(skb, arp_hdr_len(dev)))
513 /* OK, it is all there and looks valid, process... */
514 rarp = (struct arphdr *)skb_transport_header(skb);
515 rarp_ptr = (unsigned char *) (rarp + 1);
517 /* One reply at a time, please. */
518 spin_lock(&ic_recv_lock);
520 /* If we already have a reply, just drop the packet */
524 /* Find the ic_device that the packet arrived on */
526 while (d && d->dev != dev)
529 goto drop_unlock; /* should never happen */
531 /* Extract variable-width fields */
532 rarp_ptr += dev->addr_len;
533 memcpy(&sip, rarp_ptr, 4);
536 rarp_ptr += dev->addr_len;
537 memcpy(&tip, rarp_ptr, 4);
539 /* Discard packets which are not meant for us. */
540 if (memcmp(tha, dev->dev_addr, dev->addr_len))
543 /* Discard packets which are not from specified server. */
544 if (ic_servaddr != NONE && ic_servaddr != sip)
547 /* We have a winner! */
549 if (ic_myaddr == NONE)
552 ic_addrservaddr = sip;
553 ic_got_reply = IC_RARP;
556 /* Show's over. Nothing to see here. */
557 spin_unlock(&ic_recv_lock);
560 /* Throw the packet out. */
567 * Send RARP request packet over a single interface.
569 static void __init ic_rarp_send_if(struct ic_device *d)
571 struct net_device *dev = d->dev;
572 arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL,
573 dev->dev_addr, dev->dev_addr);
578 * Predefine Nameservers
580 static inline void __init ic_nameservers_predef(void)
584 for (i = 0; i < CONF_NAMESERVERS_MAX; i++)
585 ic_nameservers[i] = NONE;
588 /* Predefine NTP servers */
589 static inline void __init ic_ntp_servers_predef(void)
593 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++)
594 ic_ntp_servers[i] = NONE;
598 * DHCP/BOOTP support.
601 #ifdef IPCONFIG_BOOTP
603 struct bootp_pkt { /* BOOTP packet format */
604 struct iphdr iph; /* IP header */
605 struct udphdr udph; /* UDP header */
606 u8 op; /* 1=request, 2=reply */
607 u8 htype; /* HW address type */
608 u8 hlen; /* HW address length */
609 u8 hops; /* Used only by gateways */
610 __be32 xid; /* Transaction ID */
611 __be16 secs; /* Seconds since we started */
612 __be16 flags; /* Just what it says */
613 __be32 client_ip; /* Client's IP address if known */
614 __be32 your_ip; /* Assigned IP address */
615 __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */
616 __be32 relay_ip; /* IP address of BOOTP relay */
617 u8 hw_addr[16]; /* Client's HW address */
618 u8 serv_name[64]; /* Server host name */
619 u8 boot_file[128]; /* Name of boot file */
620 u8 exten[312]; /* DHCP options / BOOTP vendor extensions */
624 #define BOOTP_REQUEST 1
625 #define BOOTP_REPLY 2
627 /* DHCP message types */
628 #define DHCPDISCOVER 1
630 #define DHCPREQUEST 3
631 #define DHCPDECLINE 4
634 #define DHCPRELEASE 7
637 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev);
639 static struct packet_type bootp_packet_type __initdata = {
640 .type = cpu_to_be16(ETH_P_IP),
641 .func = ic_bootp_recv,
645 * Initialize DHCP/BOOTP extension fields in the request.
648 static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 };
653 ic_dhcp_init_options(u8 *options, struct ic_device *d)
655 u8 mt = ((ic_servaddr == NONE)
656 ? DHCPDISCOVER : DHCPREQUEST);
660 pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name);
662 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
665 *e++ = 53; /* DHCP message type */
669 if (mt == DHCPREQUEST) {
670 *e++ = 54; /* Server ID (IP address) */
672 memcpy(e, &ic_servaddr, 4);
675 *e++ = 50; /* Requested IP address */
677 memcpy(e, &ic_myaddr, 4);
683 static const u8 ic_req_params[] = {
685 3, /* Default gateway */
688 15, /* Domain name */
691 40, /* NIS domain name */
692 42, /* NTP servers */
695 *e++ = 55; /* Parameter request list */
696 *e++ = sizeof(ic_req_params);
697 memcpy(e, ic_req_params, sizeof(ic_req_params));
698 e += sizeof(ic_req_params);
700 if (ic_host_name_set) {
701 *e++ = 12; /* host-name */
702 len = strlen(utsname()->nodename);
704 memcpy(e, utsname()->nodename, len);
707 if (*vendor_class_identifier) {
708 pr_info("DHCP: sending class identifier \"%s\"\n",
709 vendor_class_identifier);
710 *e++ = 60; /* Class-identifier */
711 len = strlen(vendor_class_identifier);
713 memcpy(e, vendor_class_identifier, len);
716 len = strlen(dhcp_client_identifier + 1);
717 /* the minimum length of identifier is 2, include 1 byte type,
718 * and can not be larger than the length of options
720 if (len >= 1 && len < 312 - (e - options) - 1) {
723 memcpy(e, dhcp_client_identifier, len + 1);
728 *e++ = 255; /* End of the list */
731 #endif /* IPCONFIG_DHCP */
733 static void __init ic_bootp_init_ext(u8 *e)
735 memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */
737 *e++ = 1; /* Subnet mask request */
740 *e++ = 3; /* Default gateway request */
743 #if CONF_NAMESERVERS_MAX > 0
744 *e++ = 6; /* (DNS) name server request */
745 *e++ = 4 * CONF_NAMESERVERS_MAX;
746 e += 4 * CONF_NAMESERVERS_MAX;
748 *e++ = 12; /* Host name request */
751 *e++ = 40; /* NIS Domain name request */
754 *e++ = 17; /* Boot path */
758 *e++ = 57; /* set extension buffer size for reply */
760 *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */
763 *e++ = 255; /* End of the list */
768 * Initialize the DHCP/BOOTP mechanism.
770 static inline void __init ic_bootp_init(void)
772 /* Re-initialise all name servers and NTP servers to NONE, in case any
773 * were set via the "ip=" or "nfsaddrs=" kernel command line parameters:
774 * any IP addresses specified there will already have been decoded but
775 * are no longer needed
777 ic_nameservers_predef();
778 ic_ntp_servers_predef();
780 dev_add_pack(&bootp_packet_type);
785 * DHCP/BOOTP cleanup.
787 static inline void __init ic_bootp_cleanup(void)
789 dev_remove_pack(&bootp_packet_type);
794 * Send DHCP/BOOTP request to single interface.
796 static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff)
798 struct net_device *dev = d->dev;
802 int hlen = LL_RESERVED_SPACE(dev);
803 int tlen = dev->needed_tailroom;
805 /* Allocate packet */
806 skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15,
810 skb_reserve(skb, hlen);
811 b = skb_put_zero(skb, sizeof(struct bootp_pkt));
813 /* Construct IP header */
814 skb_reset_network_header(skb);
818 h->tot_len = htons(sizeof(struct bootp_pkt));
819 h->frag_off = htons(IP_DF);
821 h->protocol = IPPROTO_UDP;
822 h->daddr = htonl(INADDR_BROADCAST);
823 h->check = ip_fast_csum((unsigned char *) h, h->ihl);
825 /* Construct UDP header */
826 b->udph.source = htons(68);
827 b->udph.dest = htons(67);
828 b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr));
829 /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */
831 /* Construct DHCP/BOOTP header */
832 b->op = BOOTP_REQUEST;
833 if (dev->type < 256) /* check for false types */
834 b->htype = dev->type;
835 else if (dev->type == ARPHRD_FDDI)
836 b->htype = ARPHRD_ETHER;
838 pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type,
840 b->htype = dev->type; /* can cause undefined behavior */
843 /* server_ip and your_ip address are both already zero per RFC2131 */
844 b->hlen = dev->addr_len;
845 memcpy(b->hw_addr, dev->dev_addr, dev->addr_len);
846 b->secs = htons(jiffies_diff / HZ);
849 /* add DHCP options or BOOTP extensions */
851 if (ic_proto_enabled & IC_USE_DHCP)
852 ic_dhcp_init_options(b->exten, d);
855 ic_bootp_init_ext(b->exten);
857 /* Chain packet down the line... */
859 skb->protocol = htons(ETH_P_IP);
860 if (dev_hard_header(skb, dev, ntohs(skb->protocol),
861 dev->broadcast, dev->dev_addr, skb->len) < 0) {
867 if (dev_queue_xmit(skb) < 0)
873 * Copy BOOTP-supplied string
875 static int __init ic_bootp_string(char *dest, char *src, int len, int max)
881 memcpy(dest, src, len);
888 * Process BOOTP extensions.
890 static void __init ic_do_bootp_ext(u8 *ext)
898 pr_debug("DHCP/BOOTP: Got extension %d:", *ext);
899 for (c=ext+2; c<ext+2+ext[1]; c++)
900 pr_debug(" %02x", *c);
904 case 1: /* Subnet mask */
905 if (ic_netmask == NONE)
906 memcpy(&ic_netmask, ext+1, 4);
908 case 3: /* Default gateway */
909 if (ic_gateway == NONE)
910 memcpy(&ic_gateway, ext+1, 4);
912 case 6: /* DNS server */
914 if (servers > CONF_NAMESERVERS_MAX)
915 servers = CONF_NAMESERVERS_MAX;
916 for (i = 0; i < servers; i++) {
917 if (ic_nameservers[i] == NONE)
918 memcpy(&ic_nameservers[i], ext+1+4*i, 4);
921 case 12: /* Host name */
922 if (!ic_host_name_set) {
923 ic_bootp_string(utsname()->nodename, ext+1, *ext,
925 ic_host_name_set = 1;
928 case 15: /* Domain name (DNS) */
930 ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain));
932 case 17: /* Root path */
933 if (!root_server_path[0])
934 ic_bootp_string(root_server_path, ext+1, *ext,
935 sizeof(root_server_path));
937 case 26: /* Interface MTU */
938 memcpy(&mtu, ext+1, sizeof(mtu));
939 ic_dev_mtu = ntohs(mtu);
941 case 40: /* NIS Domain name (_not_ DNS) */
942 ic_bootp_string(utsname()->domainname, ext+1, *ext,
945 case 42: /* NTP servers */
947 if (servers > CONF_NTP_SERVERS_MAX)
948 servers = CONF_NTP_SERVERS_MAX;
949 for (i = 0; i < servers; i++) {
950 if (ic_ntp_servers[i] == NONE)
951 memcpy(&ic_ntp_servers[i], ext+1+4*i, 4);
959 * Receive BOOTP reply.
961 static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev)
968 if (!net_eq(dev_net(dev), &init_net))
971 /* Perform verifications before taking the lock. */
972 if (skb->pkt_type == PACKET_OTHERHOST)
975 skb = skb_share_check(skb, GFP_ATOMIC);
979 if (!pskb_may_pull(skb,
980 sizeof(struct iphdr) +
981 sizeof(struct udphdr)))
984 b = (struct bootp_pkt *)skb_network_header(skb);
987 if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP)
990 /* Fragments are not supported */
991 if (ip_is_fragment(h)) {
992 net_err_ratelimited("DHCP/BOOTP: Ignoring fragmented reply\n");
996 if (skb->len < ntohs(h->tot_len))
999 if (ip_fast_csum((char *) h, h->ihl))
1002 if (b->udph.source != htons(67) || b->udph.dest != htons(68))
1005 if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr))
1008 len = ntohs(b->udph.len) - sizeof(struct udphdr);
1009 ext_len = len - (sizeof(*b) -
1010 sizeof(struct iphdr) -
1011 sizeof(struct udphdr) -
1016 /* Ok the front looks good, make sure we can get at the rest. */
1017 if (!pskb_may_pull(skb, skb->len))
1020 b = (struct bootp_pkt *)skb_network_header(skb);
1023 /* One reply at a time, please. */
1024 spin_lock(&ic_recv_lock);
1026 /* If we already have a reply, just drop the packet */
1030 /* Find the ic_device that the packet arrived on */
1032 while (d && d->dev != dev)
1035 goto drop_unlock; /* should never happen */
1037 /* Is it a reply to our BOOTP request? */
1038 if (b->op != BOOTP_REPLY ||
1040 net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n",
1041 d->dev->name, b->op, b->xid);
1045 /* Parse extensions */
1047 !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */
1048 u8 *end = (u8 *) b + ntohs(b->iph.tot_len);
1051 #ifdef IPCONFIG_DHCP
1052 if (ic_proto_enabled & IC_USE_DHCP) {
1053 __be32 server_id = NONE;
1057 while (ext < end && *ext != 0xff) {
1059 if (*opt == 0) /* Padding */
1065 case 53: /* Message type */
1069 case 54: /* Server ID (IP address) */
1071 memcpy(&server_id, opt + 2, 4);
1076 pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name);
1080 /* While in the process of accepting one offer,
1081 * ignore all others.
1083 if (ic_myaddr != NONE)
1086 /* Let's accept that offer. */
1087 ic_myaddr = b->your_ip;
1088 ic_servaddr = server_id;
1089 pr_debug("DHCP: Offered address %pI4 by server %pI4\n",
1090 &ic_myaddr, &b->iph.saddr);
1091 /* The DHCP indicated server address takes
1092 * precedence over the bootp header one if
1093 * they are different.
1095 if ((server_id != NONE) &&
1096 (b->server_ip != server_id))
1097 b->server_ip = ic_servaddr;
1101 if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0)
1108 /* Urque. Forget it*/
1114 ic_dhcp_msgtype = mt;
1117 #endif /* IPCONFIG_DHCP */
1120 while (ext < end && *ext != 0xff) {
1122 if (*opt == 0) /* Padding */
1126 ic_do_bootp_ext(opt);
1130 /* We have a winner! */
1132 ic_myaddr = b->your_ip;
1133 ic_servaddr = b->server_ip;
1134 ic_addrservaddr = b->iph.saddr;
1135 if (ic_gateway == NONE && b->relay_ip)
1136 ic_gateway = b->relay_ip;
1137 if (ic_nameservers[0] == NONE)
1138 ic_nameservers[0] = ic_servaddr;
1139 ic_got_reply = IC_BOOTP;
1142 /* Show's over. Nothing to see here. */
1143 spin_unlock(&ic_recv_lock);
1146 /* Throw the packet out. */
1157 * Dynamic IP configuration -- DHCP, BOOTP, RARP.
1160 #ifdef IPCONFIG_DYNAMIC
1162 static int __init ic_dynamic(void)
1165 struct ic_device *d;
1166 unsigned long start_jiffies, timeout, jiff;
1167 int do_bootp = ic_proto_have_if & IC_BOOTP;
1168 int do_rarp = ic_proto_have_if & IC_RARP;
1171 * If none of DHCP/BOOTP/RARP was selected, return with an error.
1172 * This routine gets only called when some pieces of information
1173 * are missing, and without DHCP/BOOTP/RARP we are unable to get it.
1175 if (!ic_proto_enabled) {
1176 pr_err("IP-Config: Incomplete network configuration information\n");
1180 #ifdef IPCONFIG_BOOTP
1181 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP)
1182 pr_err("DHCP/BOOTP: No suitable device found\n");
1184 #ifdef IPCONFIG_RARP
1185 if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP)
1186 pr_err("RARP: No suitable device found\n");
1189 if (!ic_proto_have_if)
1190 /* Error message already printed */
1196 #ifdef IPCONFIG_BOOTP
1200 #ifdef IPCONFIG_RARP
1206 * Send requests and wait, until we get an answer. This loop
1207 * seems to be a terrible waste of CPU time, but actually there is
1208 * only one process running at all, so we don't need to use any
1209 * scheduler functions.
1210 * [Actually we could now, but the nothing else running note still
1213 pr_notice("Sending %s%s%s requests .",
1215 ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "",
1216 (do_bootp && do_rarp) ? " and " : "",
1217 do_rarp ? "RARP" : "");
1219 start_jiffies = jiffies;
1221 retries = CONF_SEND_RETRIES;
1222 get_random_bytes(&timeout, sizeof(timeout));
1223 timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned int) CONF_TIMEOUT_RANDOM);
1225 #ifdef IPCONFIG_BOOTP
1226 if (do_bootp && (d->able & IC_BOOTP))
1227 ic_bootp_send_if(d, jiffies - start_jiffies);
1229 #ifdef IPCONFIG_RARP
1230 if (do_rarp && (d->able & IC_RARP))
1235 jiff = jiffies + timeout;
1236 while (time_before(jiffies, jiff) && !ic_got_reply)
1237 schedule_timeout_uninterruptible(1);
1239 #ifdef IPCONFIG_DHCP
1240 /* DHCP isn't done until we get a DHCPACK. */
1241 if ((ic_got_reply & IC_BOOTP) &&
1242 (ic_proto_enabled & IC_USE_DHCP) &&
1243 ic_dhcp_msgtype != DHCPACK) {
1245 /* continue on device that got the reply */
1250 #endif /* IPCONFIG_DHCP */
1261 pr_cont(" timed out!\n");
1267 timeout = timeout CONF_TIMEOUT_MULT;
1268 if (timeout > CONF_TIMEOUT_MAX)
1269 timeout = CONF_TIMEOUT_MAX;
1274 #ifdef IPCONFIG_BOOTP
1278 #ifdef IPCONFIG_RARP
1283 if (!ic_got_reply) {
1288 pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n",
1289 ((ic_got_reply & IC_RARP) ? "RARP"
1290 : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"),
1291 &ic_addrservaddr, &ic_myaddr);
1296 #endif /* IPCONFIG_DYNAMIC */
1298 #ifdef CONFIG_PROC_FS
1299 /* proc_dir_entry for /proc/net/ipconfig */
1300 static struct proc_dir_entry *ipconfig_dir;
1303 static int pnp_seq_show(struct seq_file *seq, void *v)
1307 if (ic_proto_used & IC_PROTO)
1308 seq_printf(seq, "#PROTO: %s\n",
1309 (ic_proto_used & IC_RARP) ? "RARP"
1310 : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP");
1312 seq_puts(seq, "#MANUAL\n");
1316 "domain %s\n", ic_domain);
1317 for (i = 0; i < CONF_NAMESERVERS_MAX; i++) {
1318 if (ic_nameservers[i] != NONE)
1319 seq_printf(seq, "nameserver %pI4\n",
1320 &ic_nameservers[i]);
1322 if (ic_servaddr != NONE)
1323 seq_printf(seq, "bootserver %pI4\n",
1328 /* Create the /proc/net/ipconfig directory */
1329 static int __init ipconfig_proc_net_init(void)
1331 ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net);
1338 /* Create a new file under /proc/net/ipconfig */
1339 static int ipconfig_proc_net_create(const char *name,
1340 const struct proc_ops *proc_ops)
1343 struct proc_dir_entry *p;
1348 pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name);
1352 p = proc_create(pname, 0444, init_net.proc_net, proc_ops);
1360 /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */
1361 static int ntp_servers_show(struct seq_file *seq, void *v)
1365 for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1366 if (ic_ntp_servers[i] != NONE)
1367 seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]);
1371 DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers);
1372 #endif /* CONFIG_PROC_FS */
1375 * Extract IP address from the parameter string if needed. Note that we
1376 * need to have root_server_addr set _before_ IPConfig gets called as it
1379 __be32 __init root_nfs_parse_addr(char *name)
1386 while (octets < 4) {
1387 while (*cp >= '0' && *cp <= '9')
1389 if (cp == cq || cp - cq > 3)
1391 if (*cp == '.' || octets == 3)
1397 if (octets == 4 && (*cp == ':' || *cp == '\0')) {
1400 addr = in_aton(name);
1401 memmove(name, cp, strlen(cp) + 1);
1408 #define DEVICE_WAIT_MAX 12 /* 12 seconds */
1410 static int __init wait_for_devices(void)
1414 for (i = 0; i < DEVICE_WAIT_MAX; i++) {
1415 struct net_device *dev;
1418 /* make sure deferred device probes are finished */
1419 wait_for_device_probe();
1422 for_each_netdev(&init_net, dev) {
1423 if (ic_is_init_dev(dev)) {
1437 * IP Autoconfig dispatcher.
1440 static int __init ip_auto_config(void)
1443 #ifdef IPCONFIG_DYNAMIC
1444 int retries = CONF_OPEN_RETRIES;
1447 unsigned int i, count;
1449 /* Initialise all name servers and NTP servers to NONE (but only if the
1450 * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded,
1451 * otherwise we'll overwrite the IP addresses specified there)
1453 if (ic_set_manually == 0) {
1454 ic_nameservers_predef();
1455 ic_ntp_servers_predef();
1458 #ifdef CONFIG_PROC_FS
1459 proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show);
1461 if (ipconfig_proc_net_init() == 0)
1462 ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops);
1463 #endif /* CONFIG_PROC_FS */
1468 pr_debug("IP-Config: Entered.\n");
1469 #ifdef IPCONFIG_DYNAMIC
1472 /* Wait for devices to appear */
1473 err = wait_for_devices();
1477 /* Setup all network devices */
1478 err = ic_open_devs();
1482 /* Give drivers a chance to settle */
1483 msleep(CONF_POST_OPEN);
1486 * If the config information is insufficient (e.g., our IP address or
1487 * IP address of the boot server is missing or we have multiple network
1488 * interfaces and no default was set), use BOOTP or RARP to get the
1491 if (ic_myaddr == NONE ||
1492 #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT)
1493 (root_server_addr == NONE &&
1494 ic_servaddr == NONE &&
1495 (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) ||
1497 ic_first_dev->next) {
1498 #ifdef IPCONFIG_DYNAMIC
1499 if (ic_dynamic() < 0) {
1503 * I don't know why, but sometimes the
1504 * eepro100 driver (at least) gets upset and
1505 * doesn't work the first time it's opened.
1506 * But then if you close it and reopen it, it
1507 * works just fine. So we need to try that at
1508 * least once before giving up.
1510 * Also, if the root will be NFS-mounted, we
1511 * have nowhere to go if DHCP fails. So we
1512 * just have to keep trying forever.
1516 #ifdef CONFIG_ROOT_NFS
1517 if (ROOT_DEV == Root_NFS) {
1518 pr_err("IP-Config: Retrying forever (NFS root)...\n");
1522 #ifdef CONFIG_CIFS_ROOT
1523 if (ROOT_DEV == Root_CIFS) {
1524 pr_err("IP-Config: Retrying forever (CIFS root)...\n");
1530 pr_err("IP-Config: Reopening network devices...\n");
1534 /* Oh, well. At least we tried. */
1535 pr_err("IP-Config: Auto-configuration of network failed\n");
1538 #else /* !DYNAMIC */
1539 pr_err("IP-Config: Incomplete network configuration information\n");
1542 #endif /* IPCONFIG_DYNAMIC */
1544 /* Device selected manually or only one device -> use it */
1545 ic_dev = ic_first_dev;
1548 addr = root_nfs_parse_addr(root_server_path);
1549 if (root_server_addr == NONE)
1550 root_server_addr = addr;
1553 * Use defaults wherever applicable.
1555 if (ic_defaults() < 0)
1559 * Record which protocol was actually used.
1561 #ifdef IPCONFIG_DYNAMIC
1562 ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP);
1565 #ifndef IPCONFIG_SILENT
1567 * Clue in the operator.
1569 pr_info("IP-Config: Complete:\n");
1571 pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n",
1572 ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr,
1573 &ic_myaddr, &ic_netmask, &ic_gateway);
1574 pr_info(" host=%s, domain=%s, nis-domain=%s\n",
1575 utsname()->nodename, ic_domain, utsname()->domainname);
1576 pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s",
1577 &ic_servaddr, &root_server_addr, root_server_path);
1579 pr_cont(", mtu=%d", ic_dev_mtu);
1580 /* Name servers (if any): */
1581 for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) {
1582 if (ic_nameservers[i] != NONE) {
1584 pr_info(" nameserver%u=%pI4",
1585 i, &ic_nameservers[i]);
1587 pr_cont(", nameserver%u=%pI4",
1588 i, &ic_nameservers[i]);
1592 if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0)
1595 /* NTP servers (if any): */
1596 for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) {
1597 if (ic_ntp_servers[i] != NONE) {
1599 pr_info(" ntpserver%u=%pI4",
1600 i, &ic_ntp_servers[i]);
1602 pr_cont(", ntpserver%u=%pI4",
1603 i, &ic_ntp_servers[i]);
1607 if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0)
1610 #endif /* !SILENT */
1613 * Close all network devices except the device we've
1614 * autoconfigured and set up routes.
1616 if (ic_setup_if() < 0 || ic_setup_routes() < 0)
1626 late_initcall(ip_auto_config);
1630 * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel
1631 * command line parameter. See Documentation/admin-guide/nfs/nfsroot.rst.
1633 static int __init ic_proto_name(char *name)
1635 if (!strcmp(name, "on") || !strcmp(name, "any")) {
1638 if (!strcmp(name, "off") || !strcmp(name, "none")) {
1641 #ifdef CONFIG_IP_PNP_DHCP
1642 else if (!strncmp(name, "dhcp", 4)) {
1645 ic_proto_enabled &= ~IC_RARP;
1646 client_id = strstr(name, "dhcp,");
1650 client_id = client_id + 5;
1651 v = strchr(client_id, ',');
1655 if (kstrtou8(client_id, 0, dhcp_client_identifier))
1656 pr_debug("DHCP: Invalid client identifier type\n");
1657 strncpy(dhcp_client_identifier + 1, v + 1, 251);
1663 #ifdef CONFIG_IP_PNP_BOOTP
1664 else if (!strcmp(name, "bootp")) {
1665 ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP);
1669 #ifdef CONFIG_IP_PNP_RARP
1670 else if (!strcmp(name, "rarp")) {
1671 ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP);
1675 #ifdef IPCONFIG_DYNAMIC
1676 else if (!strcmp(name, "both")) {
1677 ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */
1684 static int __init ip_auto_config_setup(char *addrs)
1689 ic_set_manually = 1;
1693 * If any dhcp, bootp etc options are set, leave autoconfig on
1694 * and skip the below static IP processing.
1696 if (ic_proto_name(addrs))
1699 /* If no static IP is given, turn off autoconfig and bail. */
1701 strcmp(addrs, "off") == 0 ||
1702 strcmp(addrs, "none") == 0) {
1707 /* Initialise all name servers and NTP servers to NONE */
1708 ic_nameservers_predef();
1709 ic_ntp_servers_predef();
1711 /* Parse string for static IP assignment. */
1714 if ((cp = strchr(ip, ':')))
1716 if (strlen(ip) > 0) {
1717 pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip);
1720 if ((ic_myaddr = in_aton(ip)) == ANY)
1724 if ((ic_servaddr = in_aton(ip)) == ANY)
1728 if ((ic_gateway = in_aton(ip)) == ANY)
1732 if ((ic_netmask = in_aton(ip)) == ANY)
1736 if ((dp = strchr(ip, '.'))) {
1738 strlcpy(utsname()->domainname, dp,
1739 sizeof(utsname()->domainname));
1741 strlcpy(utsname()->nodename, ip,
1742 sizeof(utsname()->nodename));
1743 ic_host_name_set = 1;
1746 strlcpy(user_dev_name, ip, sizeof(user_dev_name));
1749 if (ic_proto_name(ip) == 0 &&
1750 ic_myaddr == NONE) {
1755 if (CONF_NAMESERVERS_MAX >= 1) {
1756 ic_nameservers[0] = in_aton(ip);
1757 if (ic_nameservers[0] == ANY)
1758 ic_nameservers[0] = NONE;
1762 if (CONF_NAMESERVERS_MAX >= 2) {
1763 ic_nameservers[1] = in_aton(ip);
1764 if (ic_nameservers[1] == ANY)
1765 ic_nameservers[1] = NONE;
1769 if (CONF_NTP_SERVERS_MAX >= 1) {
1770 ic_ntp_servers[0] = in_aton(ip);
1771 if (ic_ntp_servers[0] == ANY)
1772 ic_ntp_servers[0] = NONE;
1783 __setup("ip=", ip_auto_config_setup);
1785 static int __init nfsaddrs_config_setup(char *addrs)
1787 return ip_auto_config_setup(addrs);
1789 __setup("nfsaddrs=", nfsaddrs_config_setup);
1791 static int __init vendor_class_identifier_setup(char *addrs)
1793 if (strlcpy(vendor_class_identifier, addrs,
1794 sizeof(vendor_class_identifier))
1795 >= sizeof(vendor_class_identifier))
1796 pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n",
1797 vendor_class_identifier);
1800 __setup("dhcpclass=", vendor_class_identifier_setup);
1802 static int __init set_carrier_timeout(char *str)
1809 ret = kstrtouint(str, 0, &carrier_timeout);
1815 __setup("carrier_timeout=", set_carrier_timeout);