/* * $Id: ipconfig.c,v 1.46 2002/02/01 22:01:04 davem Exp $ * * Automatic Configuration of IP -- use DHCP, BOOTP, RARP, or * user-supplied information to configure own IP address and routes. * * Copyright (C) 1996-1998 Martin Mares <mj@atrey.karlin.mff.cuni.cz> * * Derived from network configuration code in fs/nfs/nfsroot.c, * originally Copyright (C) 1995, 1996 Gero Kuhlmann and me. * * BOOTP rewritten to construct and analyse packets itself instead * of misusing the IP layer. num_bugs_causing_wrong_arp_replies--; * -- MJ, December 1998 * * Fixed ip_auto_config_setup calling at startup in the new "Linker Magic" * initialization scheme. * - Arnaldo Carvalho de Melo <acme@conectiva.com.br>, 08/11/1999 * * DHCP support added. To users this looks like a whole separate * protocol, but we know it's just a bag on the side of BOOTP. * -- Chip Salzenberg <chip@valinux.com>, May 2000 * * Ported DHCP support from 2.2.16 to 2.4.0-test4 * -- Eric Biederman <ebiederman@lnxi.com>, 30 Aug 2000 * * Merged changes from 2.2.19 into 2.4.3 * -- Eric Biederman <ebiederman@lnxi.com>, 22 April Aug 2001 * * Multiple Nameservers in /proc/net/pnp * -- Josef Siemes <jsiemes@web.de>, Aug 2002 */ #include <linux/config.h> #include <linux/types.h> #include <linux/string.h> #include <linux/kernel.h> #include <linux/jiffies.h> #include <linux/random.h> #include <linux/init.h> #include <linux/utsname.h> #include <linux/in.h> #include <linux/if.h> #include <linux/inet.h> #include <linux/netdevice.h> #include <linux/if_arp.h> #include <linux/skbuff.h> #include <linux/ip.h> #include <linux/socket.h> #include <linux/route.h> #include <linux/udp.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/major.h> #include <linux/root_dev.h> #include <linux/delay.h> #include <net/arp.h> #include <net/ip.h> #include <net/ipconfig.h> #include <asm/uaccess.h> #include <net/checksum.h> #include <asm/processor.h> /* Define this to allow debugging output */ #undef IPCONFIG_DEBUG #ifdef IPCONFIG_DEBUG #define DBG(x) printk x #else #define DBG(x) do { } while(0) #endif #if defined(CONFIG_IP_PNP_DHCP) #define IPCONFIG_DHCP #endif #if defined(CONFIG_IP_PNP_BOOTP) || defined(CONFIG_IP_PNP_DHCP) #define IPCONFIG_BOOTP #endif #if defined(CONFIG_IP_PNP_RARP) #define IPCONFIG_RARP #endif #if defined(IPCONFIG_BOOTP) || defined(IPCONFIG_RARP) #define IPCONFIG_DYNAMIC #endif /* Define the friendly delay before and after opening net devices */ #define CONF_PRE_OPEN 500 /* Before opening: 1/2 second */ #define CONF_POST_OPEN 1 /* After opening: 1 second */ /* Define the timeout for waiting for a DHCP/BOOTP/RARP reply */ #define CONF_OPEN_RETRIES 2 /* (Re)open devices twice */ #define CONF_SEND_RETRIES 6 /* Send six requests per open */ #define CONF_INTER_TIMEOUT (HZ/2) /* Inter-device timeout: 1/2 second */ #define CONF_BASE_TIMEOUT (HZ*2) /* Initial timeout: 2 seconds */ #define CONF_TIMEOUT_RANDOM (HZ) /* Maximum amount of randomization */ #define CONF_TIMEOUT_MULT *7/4 /* Rate of timeout growth */ #define CONF_TIMEOUT_MAX (HZ*30) /* Maximum allowed timeout */ #define CONF_NAMESERVERS_MAX 3 /* Maximum number of nameservers - '3' from resolv.h */ /* * Public IP configuration */ /* This is used by platforms which might be able to set the ipconfig * variables using firmware environment vars. If this is set, it will * ignore such firmware variables. */ int ic_set_manually __initdata = 0; /* IPconfig parameters set manually */ static int ic_enable __initdata = 0; /* IP config enabled? */ /* Protocol choice */ int ic_proto_enabled __initdata = 0 #ifdef IPCONFIG_BOOTP | IC_BOOTP #endif #ifdef CONFIG_IP_PNP_DHCP | IC_USE_DHCP #endif #ifdef IPCONFIG_RARP | IC_RARP #endif ; static int ic_host_name_set __initdata = 0; /* Host name set by us? */ u32 ic_myaddr = INADDR_NONE; /* My IP address */ static u32 ic_netmask = INADDR_NONE; /* Netmask for local subnet */ u32 ic_gateway = INADDR_NONE; /* Gateway IP address */ u32 ic_servaddr = INADDR_NONE; /* Boot server IP address */ u32 root_server_addr = INADDR_NONE; /* Address of NFS server */ u8 root_server_path[256] = { 0, }; /* Path to mount as root */ /* Persistent data: */ static int ic_proto_used; /* Protocol used, if any */ static u32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */ static u8 ic_domain[64]; /* DNS (not NIS) domain name */ /* * Private state. */ /* Name of user-selected boot device */ static char user_dev_name[IFNAMSIZ] __initdata = { 0, }; /* Protocols supported by available interfaces */ static int ic_proto_have_if __initdata = 0; #ifdef IPCONFIG_DYNAMIC static DEFINE_SPINLOCK(ic_recv_lock); static volatile int ic_got_reply __initdata = 0; /* Proto(s) that replied */ #endif #ifdef IPCONFIG_DHCP static int ic_dhcp_msgtype __initdata = 0; /* DHCP msg type received */ #endif /* * Network devices */ struct ic_device { struct ic_device *next; struct net_device *dev; unsigned short flags; short able; u32 xid; }; static struct ic_device *ic_first_dev __initdata = NULL;/* List of open device */ static struct net_device *ic_dev __initdata = NULL; /* Selected device */ static int __init ic_open_devs(void) { struct ic_device *d, **last; struct net_device *dev; unsigned short oflags; last = &ic_first_dev; rtnl_shlock(); /* bring loopback device up first */ if (dev_change_flags(&loopback_dev, loopback_dev.flags | IFF_UP) < 0) printk(KERN_ERR "IP-Config: Failed to open %s\n", loopback_dev.name); for (dev = dev_base; dev; dev = dev->next) { if (dev == &loopback_dev) continue; if (user_dev_name[0] ? !strcmp(dev->name, user_dev_name) : (!(dev->flags & IFF_LOOPBACK) && (dev->flags & (IFF_POINTOPOINT|IFF_BROADCAST)) && strncmp(dev->name, "dummy", 5))) { int able = 0; if (dev->mtu >= 364) able |= IC_BOOTP; else printk(KERN_WARNING "DHCP/BOOTP: Ignoring device %s, MTU %d too small", dev->name, dev->mtu); if (!(dev->flags & IFF_NOARP)) able |= IC_RARP; able &= ic_proto_enabled; if (ic_proto_enabled && !able) continue; oflags = dev->flags; if (dev_change_flags(dev, oflags | IFF_UP) < 0) { printk(KERN_ERR "IP-Config: Failed to open %s\n", dev->name); continue; } if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) { rtnl_shunlock(); return -1; } d->dev = dev; *last = d; last = &d->next; d->flags = oflags; d->able = able; if (able & IC_BOOTP) get_random_bytes(&d->xid, sizeof(u32)); else d->xid = 0; ic_proto_have_if |= able; DBG(("IP-Config: %s UP (able=%d, xid=%08x)\n", dev->name, able, d->xid)); } } rtnl_shunlock(); *last = NULL; if (!ic_first_dev) { if (user_dev_name[0]) printk(KERN_ERR "IP-Config: Device `%s' not found.\n", user_dev_name); else printk(KERN_ERR "IP-Config: No network devices available.\n"); return -1; } return 0; } static void __init ic_close_devs(void) { struct ic_device *d, *next; struct net_device *dev; rtnl_shlock(); next = ic_first_dev; while ((d = next)) { next = d->next; dev = d->dev; if (dev != ic_dev) { DBG(("IP-Config: Downing %s\n", dev->name)); dev_change_flags(dev, d->flags); } kfree(d); } rtnl_shunlock(); } /* * Interface to various network functions. */ static inline void set_sockaddr(struct sockaddr_in *sin, u32 addr, u16 port) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = addr; sin->sin_port = port; } static int __init ic_dev_ioctl(unsigned int cmd, struct ifreq *arg) { int res; mm_segment_t oldfs = get_fs(); set_fs(get_ds()); res = devinet_ioctl(cmd, (struct ifreq __user *) arg); set_fs(oldfs); return res; } static int __init ic_route_ioctl(unsigned int cmd, struct rtentry *arg) { int res; mm_segment_t oldfs = get_fs(); set_fs(get_ds()); res = ip_rt_ioctl(cmd, (void __user *) arg); set_fs(oldfs); return res; } /* * Set up interface addresses and routes. */ static int __init ic_setup_if(void) { struct ifreq ir; struct sockaddr_in *sin = (void *) &ir.ifr_ifru.ifru_addr; int err; memset(&ir, 0, sizeof(ir)); strcpy(ir.ifr_ifrn.ifrn_name, ic_dev->name); set_sockaddr(sin, ic_myaddr, 0); if ((err = ic_dev_ioctl(SIOCSIFADDR, &ir)) < 0) { printk(KERN_ERR "IP-Config: Unable to set interface address (%d).\n", err); return -1; } set_sockaddr(sin, ic_netmask, 0); if ((err = ic_dev_ioctl(SIOCSIFNETMASK, &ir)) < 0) { printk(KERN_ERR "IP-Config: Unable to set interface netmask (%d).\n", err); return -1; } set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0); if ((err = ic_dev_ioctl(SIOCSIFBRDADDR, &ir)) < 0) { printk(KERN_ERR "IP-Config: Unable to set interface broadcast address (%d).\n", err); return -1; } return 0; } static int __init ic_setup_routes(void) { /* No need to setup device routes, only the default route... */ if (ic_gateway != INADDR_NONE) { struct rtentry rm; int err; memset(&rm, 0, sizeof(rm)); if ((ic_gateway ^ ic_myaddr) & ic_netmask) { printk(KERN_ERR "IP-Config: Gateway not on directly connected network.\n"); return -1; } set_sockaddr((struct sockaddr_in *) &rm.rt_dst, 0, 0); set_sockaddr((struct sockaddr_in *) &rm.rt_genmask, 0, 0); set_sockaddr((struct sockaddr_in *) &rm.rt_gateway, ic_gateway, 0); rm.rt_flags = RTF_UP | RTF_GATEWAY; if ((err = ic_route_ioctl(SIOCADDRT, &rm)) < 0) { printk(KERN_ERR "IP-Config: Cannot add default route (%d).\n", err); return -1; } } return 0; } /* * Fill in default values for all missing parameters. */ static int __init ic_defaults(void) { /* * At this point we have no userspace running so need not * claim locks on system_utsname */ if (!ic_host_name_set) sprintf(system_utsname.nodename, "%u.%u.%u.%u", NIPQUAD(ic_myaddr)); if (root_server_addr == INADDR_NONE) root_server_addr = ic_servaddr; if (ic_netmask == INADDR_NONE) { if (IN_CLASSA(ntohl(ic_myaddr))) ic_netmask = htonl(IN_CLASSA_NET); else if (IN_CLASSB(ntohl(ic_myaddr))) ic_netmask = htonl(IN_CLASSB_NET); else if (IN_CLASSC(ntohl(ic_myaddr))) ic_netmask = htonl(IN_CLASSC_NET); else { printk(KERN_ERR "IP-Config: Unable to guess netmask for address %u.%u.%u.%u\n", NIPQUAD(ic_myaddr)); return -1; } printk("IP-Config: Guessing netmask %u.%u.%u.%u\n", NIPQUAD(ic_netmask)); } return 0; } /* * RARP support. */ #ifdef IPCONFIG_RARP static int ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); static struct packet_type rarp_packet_type __initdata = { .type = __constant_htons(ETH_P_RARP), .func = ic_rarp_recv, }; static inline void ic_rarp_init(void) { dev_add_pack(&rarp_packet_type); } static inline void ic_rarp_cleanup(void) { dev_remove_pack(&rarp_packet_type); } /* * Process received RARP packet. */ static int __init ic_rarp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct arphdr *rarp; unsigned char *rarp_ptr; unsigned long sip, tip; unsigned char *sha, *tha; /* s for "source", t for "target" */ struct ic_device *d; if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) return NET_RX_DROP; if (!pskb_may_pull(skb, sizeof(struct arphdr))) goto drop; /* Basic sanity checks can be done without the lock. */ rarp = (struct arphdr *)skb->h.raw; /* If this test doesn't pass, it's not IP, or we should * ignore it anyway. */ if (rarp->ar_hln != dev->addr_len || dev->type != ntohs(rarp->ar_hrd)) goto drop; /* If it's not a RARP reply, delete it. */ if (rarp->ar_op != htons(ARPOP_RREPLY)) goto drop; /* If it's not Ethernet, delete it. */ if (rarp->ar_pro != htons(ETH_P_IP)) goto drop; if (!pskb_may_pull(skb, sizeof(struct arphdr) + (2 * dev->addr_len) + (2 * 4))) goto drop; /* OK, it is all there and looks valid, process... */ rarp = (struct arphdr *)skb->h.raw; rarp_ptr = (unsigned char *) (rarp + 1); /* One reply at a time, please. */ spin_lock(&ic_recv_lock); /* If we already have a reply, just drop the packet */ if (ic_got_reply) goto drop_unlock; /* Find the ic_device that the packet arrived on */ d = ic_first_dev; while (d && d->dev != dev) d = d->next; if (!d) goto drop_unlock; /* should never happen */ /* Extract variable-width fields */ sha = rarp_ptr; rarp_ptr += dev->addr_len; memcpy(&sip, rarp_ptr, 4); rarp_ptr += 4; tha = rarp_ptr; rarp_ptr += dev->addr_len; memcpy(&tip, rarp_ptr, 4); /* Discard packets which are not meant for us. */ if (memcmp(tha, dev->dev_addr, dev->addr_len)) goto drop_unlock; /* Discard packets which are not from specified server. */ if (ic_servaddr != INADDR_NONE && ic_servaddr != sip) goto drop_unlock; /* We have a winner! */ ic_dev = dev; if (ic_myaddr == INADDR_NONE) ic_myaddr = tip; ic_servaddr = sip; ic_got_reply = IC_RARP; drop_unlock: /* Show's over. Nothing to see here. */ spin_unlock(&ic_recv_lock); drop: /* Throw the packet out. */ kfree_skb(skb); return 0; } /* * Send RARP request packet over a single interface. */ static void __init ic_rarp_send_if(struct ic_device *d) { struct net_device *dev = d->dev; arp_send(ARPOP_RREQUEST, ETH_P_RARP, 0, dev, 0, NULL, dev->dev_addr, dev->dev_addr); } #endif /* * DHCP/BOOTP support. */ #ifdef IPCONFIG_BOOTP struct bootp_pkt { /* BOOTP packet format */ struct iphdr iph; /* IP header */ struct udphdr udph; /* UDP header */ u8 op; /* 1=request, 2=reply */ u8 htype; /* HW address type */ u8 hlen; /* HW address length */ u8 hops; /* Used only by gateways */ u32 xid; /* Transaction ID */ u16 secs; /* Seconds since we started */ u16 flags; /* Just what it says */ u32 client_ip; /* Client's IP address if known */ u32 your_ip; /* Assigned IP address */ u32 server_ip; /* (Next, e.g. NFS) Server's IP address */ u32 relay_ip; /* IP address of BOOTP relay */ u8 hw_addr[16]; /* Client's HW address */ u8 serv_name[64]; /* Server host name */ u8 boot_file[128]; /* Name of boot file */ u8 exten[312]; /* DHCP options / BOOTP vendor extensions */ }; /* packet ops */ #define BOOTP_REQUEST 1 #define BOOTP_REPLY 2 /* DHCP message types */ #define DHCPDISCOVER 1 #define DHCPOFFER 2 #define DHCPREQUEST 3 #define DHCPDECLINE 4 #define DHCPACK 5 #define DHCPNAK 6 #define DHCPRELEASE 7 #define DHCPINFORM 8 static int ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev); static struct packet_type bootp_packet_type __initdata = { .type = __constant_htons(ETH_P_IP), .func = ic_bootp_recv, }; /* * Initialize DHCP/BOOTP extension fields in the request. */ static const u8 ic_bootp_cookie[4] = { 99, 130, 83, 99 }; #ifdef IPCONFIG_DHCP static void __init ic_dhcp_init_options(u8 *options) { u8 mt = ((ic_servaddr == INADDR_NONE) ? DHCPDISCOVER : DHCPREQUEST); u8 *e = options; #ifdef IPCONFIG_DEBUG printk("DHCP: Sending message type %d\n", mt); #endif memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */ e += 4; *e++ = 53; /* DHCP message type */ *e++ = 1; *e++ = mt; if (mt == DHCPREQUEST) { *e++ = 54; /* Server ID (IP address) */ *e++ = 4; memcpy(e, &ic_servaddr, 4); e += 4; *e++ = 50; /* Requested IP address */ *e++ = 4; memcpy(e, &ic_myaddr, 4); e += 4; } /* always? */ { static const u8 ic_req_params[] = { 1, /* Subnet mask */ 3, /* Default gateway */ 6, /* DNS server */ 12, /* Host name */ 15, /* Domain name */ 17, /* Boot path */ 40, /* NIS domain name */ }; *e++ = 55; /* Parameter request list */ *e++ = sizeof(ic_req_params); memcpy(e, ic_req_params, sizeof(ic_req_params)); e += sizeof(ic_req_params); } *e++ = 255; /* End of the list */ } #endif /* IPCONFIG_DHCP */ static void __init ic_bootp_init_ext(u8 *e) { memcpy(e, ic_bootp_cookie, 4); /* RFC1048 Magic Cookie */ e += 4; *e++ = 1; /* Subnet mask request */ *e++ = 4; e += 4; *e++ = 3; /* Default gateway request */ *e++ = 4; e += 4; *e++ = 5; /* Name server request */ *e++ = 8; e += 8; *e++ = 12; /* Host name request */ *e++ = 32; e += 32; *e++ = 40; /* NIS Domain name request */ *e++ = 32; e += 32; *e++ = 17; /* Boot path */ *e++ = 40; e += 40; *e++ = 57; /* set extension buffer size for reply */ *e++ = 2; *e++ = 1; /* 128+236+8+20+14, see dhcpd sources */ *e++ = 150; *e++ = 255; /* End of the list */ } /* * Initialize the DHCP/BOOTP mechanism. */ static inline void ic_bootp_init(void) { int i; for (i = 0; i < CONF_NAMESERVERS_MAX; i++) ic_nameservers[i] = INADDR_NONE; dev_add_pack(&bootp_packet_type); } /* * DHCP/BOOTP cleanup. */ static inline void ic_bootp_cleanup(void) { dev_remove_pack(&bootp_packet_type); } /* * Send DHCP/BOOTP request to single interface. */ static void __init ic_bootp_send_if(struct ic_device *d, unsigned long jiffies_diff) { struct net_device *dev = d->dev; struct sk_buff *skb; struct bootp_pkt *b; int hh_len = LL_RESERVED_SPACE(dev); struct iphdr *h; /* Allocate packet */ skb = alloc_skb(sizeof(struct bootp_pkt) + hh_len + 15, GFP_KERNEL); if (!skb) return; skb_reserve(skb, hh_len); b = (struct bootp_pkt *) skb_put(skb, sizeof(struct bootp_pkt)); memset(b, 0, sizeof(struct bootp_pkt)); /* Construct IP header */ skb->nh.iph = h = &b->iph; h->version = 4; h->ihl = 5; h->tot_len = htons(sizeof(struct bootp_pkt)); h->frag_off = htons(IP_DF); h->ttl = 64; h->protocol = IPPROTO_UDP; h->daddr = INADDR_BROADCAST; h->check = ip_fast_csum((unsigned char *) h, h->ihl); /* Construct UDP header */ b->udph.source = htons(68); b->udph.dest = htons(67); b->udph.len = htons(sizeof(struct bootp_pkt) - sizeof(struct iphdr)); /* UDP checksum not calculated -- explicitly allowed in BOOTP RFC */ /* Construct DHCP/BOOTP header */ b->op = BOOTP_REQUEST; if (dev->type < 256) /* check for false types */ b->htype = dev->type; else if (dev->type == ARPHRD_IEEE802_TR) /* fix for token ring */ b->htype = ARPHRD_IEEE802; else if (dev->type == ARPHRD_FDDI) b->htype = ARPHRD_ETHER; else { printk("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name); b->htype = dev->type; /* can cause undefined behavior */ } b->hlen = dev->addr_len; b->your_ip = INADDR_NONE; b->server_ip = INADDR_NONE; memcpy(b->hw_addr, dev->dev_addr, dev->addr_len); b->secs = htons(jiffies_diff / HZ); b->xid = d->xid; /* add DHCP options or BOOTP extensions */ #ifdef IPCONFIG_DHCP if (ic_proto_enabled & IC_USE_DHCP) ic_dhcp_init_options(b->exten); else #endif ic_bootp_init_ext(b->exten); /* Chain packet down the line... */ skb->dev = dev; skb->protocol = htons(ETH_P_IP); if ((dev->hard_header && dev->hard_header(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) || dev_queue_xmit(skb) < 0) printk("E"); } /* * Copy BOOTP-supplied string if not already set. */ static int __init ic_bootp_string(char *dest, char *src, int len, int max) { if (!len) return 0; if (len > max-1) len = max-1; memcpy(dest, src, len); dest[len] = '\0'; return 1; } /* * Process BOOTP extensions. */ static void __init ic_do_bootp_ext(u8 *ext) { u8 servers; int i; #ifdef IPCONFIG_DEBUG u8 *c; printk("DHCP/BOOTP: Got extension %d:",*ext); for(c=ext+2; c<ext+2+ext[1]; c++) printk(" %02x", *c); printk("\n"); #endif switch (*ext++) { case 1: /* Subnet mask */ if (ic_netmask == INADDR_NONE) memcpy(&ic_netmask, ext+1, 4); break; case 3: /* Default gateway */ if (ic_gateway == INADDR_NONE) memcpy(&ic_gateway, ext+1, 4); break; case 6: /* DNS server */ servers= *ext/4; if (servers > CONF_NAMESERVERS_MAX) servers = CONF_NAMESERVERS_MAX; for (i = 0; i < servers; i++) { if (ic_nameservers[i] == INADDR_NONE) memcpy(&ic_nameservers[i], ext+1+4*i, 4); } break; case 12: /* Host name */ ic_bootp_string(system_utsname.nodename, ext+1, *ext, __NEW_UTS_LEN); ic_host_name_set = 1; break; case 15: /* Domain name (DNS) */ ic_bootp_string(ic_domain, ext+1, *ext, sizeof(ic_domain)); break; case 17: /* Root path */ if (!root_server_path[0]) ic_bootp_string(root_server_path, ext+1, *ext, sizeof(root_server_path)); break; case 40: /* NIS Domain name (_not_ DNS) */ ic_bootp_string(system_utsname.domainname, ext+1, *ext, __NEW_UTS_LEN); break; } } /* * Receive BOOTP reply. */ static int __init ic_bootp_recv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct bootp_pkt *b; struct iphdr *h; struct ic_device *d; int len, ext_len; /* Perform verifications before taking the lock. */ if (skb->pkt_type == PACKET_OTHERHOST) goto drop; if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) return NET_RX_DROP; if (!pskb_may_pull(skb, sizeof(struct iphdr) + sizeof(struct udphdr))) goto drop; b = (struct bootp_pkt *) skb->nh.iph; h = &b->iph; if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP) goto drop; /* Fragments are not supported */ if (h->frag_off & htons(IP_OFFSET | IP_MF)) { if (net_ratelimit()) printk(KERN_ERR "DHCP/BOOTP: Ignoring fragmented " "reply.\n"); goto drop; } if (skb->len < ntohs(h->tot_len)) goto drop; if (ip_fast_csum((char *) h, h->ihl)) goto drop; if (b->udph.source != htons(67) || b->udph.dest != htons(68)) goto drop; if (ntohs(h->tot_len) < ntohs(b->udph.len) + sizeof(struct iphdr)) goto drop; len = ntohs(b->udph.len) - sizeof(struct udphdr); ext_len = len - (sizeof(*b) - sizeof(struct iphdr) - sizeof(struct udphdr) - sizeof(b->exten)); if (ext_len < 0) goto drop; /* Ok the front looks good, make sure we can get at the rest. */ if (!pskb_may_pull(skb, skb->len)) goto drop; b = (struct bootp_pkt *) skb->nh.iph; h = &b->iph; /* One reply at a time, please. */ spin_lock(&ic_recv_lock); /* If we already have a reply, just drop the packet */ if (ic_got_reply) goto drop_unlock; /* Find the ic_device that the packet arrived on */ d = ic_first_dev; while (d && d->dev != dev) d = d->next; if (!d) goto drop_unlock; /* should never happen */ /* Is it a reply to our BOOTP request? */ if (b->op != BOOTP_REPLY || b->xid != d->xid) { if (net_ratelimit()) printk(KERN_ERR "DHCP/BOOTP: Reply not for us, " "op[%x] xid[%x]\n", b->op, b->xid); goto drop_unlock; } /* Parse extensions */ if (ext_len >= 4 && !memcmp(b->exten, ic_bootp_cookie, 4)) { /* Check magic cookie */ u8 *end = (u8 *) b + ntohs(b->iph.tot_len); u8 *ext; #ifdef IPCONFIG_DHCP if (ic_proto_enabled & IC_USE_DHCP) { u32 server_id = INADDR_NONE; int mt = 0; ext = &b->exten[4]; while (ext < end && *ext != 0xff) { u8 *opt = ext++; if (*opt == 0) /* Padding */ continue; ext += *ext + 1; if (ext >= end) break; switch (*opt) { case 53: /* Message type */ if (opt[1]) mt = opt[2]; break; case 54: /* Server ID (IP address) */ if (opt[1] >= 4) memcpy(&server_id, opt + 2, 4); break; }; } #ifdef IPCONFIG_DEBUG printk("DHCP: Got message type %d\n", mt); #endif switch (mt) { case DHCPOFFER: /* While in the process of accepting one offer, * ignore all others. */ if (ic_myaddr != INADDR_NONE) goto drop_unlock; /* Let's accept that offer. */ ic_myaddr = b->your_ip; ic_servaddr = server_id; #ifdef IPCONFIG_DEBUG printk("DHCP: Offered address %u.%u.%u.%u", NIPQUAD(ic_myaddr)); printk(" by server %u.%u.%u.%u\n", NIPQUAD(ic_servaddr)); #endif /* The DHCP indicated server address takes * precedence over the bootp header one if * they are different. */ if ((server_id != INADDR_NONE) && (b->server_ip != server_id)) b->server_ip = ic_servaddr; break; case DHCPACK: if (memcmp(dev->dev_addr, b->hw_addr, dev->addr_len) != 0) goto drop_unlock; /* Yeah! */ break; default: /* Urque. Forget it*/ ic_myaddr = INADDR_NONE; ic_servaddr = INADDR_NONE; goto drop_unlock; }; ic_dhcp_msgtype = mt; } #endif /* IPCONFIG_DHCP */ ext = &b->exten[4]; while (ext < end && *ext != 0xff) { u8 *opt = ext++; if (*opt == 0) /* Padding */ continue; ext += *ext + 1; if (ext < end) ic_do_bootp_ext(opt); } } /* We have a winner! */ ic_dev = dev; ic_myaddr = b->your_ip; ic_servaddr = b->server_ip; if (ic_gateway == INADDR_NONE && b->relay_ip) ic_gateway = b->relay_ip; if (ic_nameservers[0] == INADDR_NONE) ic_nameservers[0] = ic_servaddr; ic_got_reply = IC_BOOTP; drop_unlock: /* Show's over. Nothing to see here. */ spin_unlock(&ic_recv_lock); drop: /* Throw the packet out. */ kfree_skb(skb); return 0; } #endif /* * Dynamic IP configuration -- DHCP, BOOTP, RARP. */ #ifdef IPCONFIG_DYNAMIC static int __init ic_dynamic(void) { int retries; struct ic_device *d; unsigned long start_jiffies, timeout, jiff; int do_bootp = ic_proto_have_if & IC_BOOTP; int do_rarp = ic_proto_have_if & IC_RARP; /* * If none of DHCP/BOOTP/RARP was selected, return with an error. * This routine gets only called when some pieces of information * are missing, and without DHCP/BOOTP/RARP we are unable to get it. */ if (!ic_proto_enabled) { printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n"); return -1; } #ifdef IPCONFIG_BOOTP if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP) printk(KERN_ERR "DHCP/BOOTP: No suitable device found.\n"); #endif #ifdef IPCONFIG_RARP if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP) printk(KERN_ERR "RARP: No suitable device found.\n"); #endif if (!ic_proto_have_if) /* Error message already printed */ return -1; /* * Setup protocols */ #ifdef IPCONFIG_BOOTP if (do_bootp) ic_bootp_init(); #endif #ifdef IPCONFIG_RARP if (do_rarp) ic_rarp_init(); #endif /* * Send requests and wait, until we get an answer. This loop * seems to be a terrible waste of CPU time, but actually there is * only one process running at all, so we don't need to use any * scheduler functions. * [Actually we could now, but the nothing else running note still * applies.. - AC] */ printk(KERN_NOTICE "Sending %s%s%s requests .", do_bootp ? ((ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP") : "", (do_bootp && do_rarp) ? " and " : "", do_rarp ? "RARP" : ""); start_jiffies = jiffies; d = ic_first_dev; retries = CONF_SEND_RETRIES; get_random_bytes(&timeout, sizeof(timeout)); timeout = CONF_BASE_TIMEOUT + (timeout % (unsigned) CONF_TIMEOUT_RANDOM); for(;;) { #ifdef IPCONFIG_BOOTP if (do_bootp && (d->able & IC_BOOTP)) ic_bootp_send_if(d, jiffies - start_jiffies); #endif #ifdef IPCONFIG_RARP if (do_rarp && (d->able & IC_RARP)) ic_rarp_send_if(d); #endif jiff = jiffies + (d->next ? CONF_INTER_TIMEOUT : timeout); while (time_before(jiffies, jiff) && !ic_got_reply) { set_current_state(TASK_UNINTERRUPTIBLE); schedule_timeout(1); } #ifdef IPCONFIG_DHCP /* DHCP isn't done until we get a DHCPACK. */ if ((ic_got_reply & IC_BOOTP) && (ic_proto_enabled & IC_USE_DHCP) && ic_dhcp_msgtype != DHCPACK) { ic_got_reply = 0; printk(","); continue; } #endif /* IPCONFIG_DHCP */ if (ic_got_reply) { printk(" OK\n"); break; } if ((d = d->next)) continue; if (! --retries) { printk(" timed out!\n"); break; } d = ic_first_dev; timeout = timeout CONF_TIMEOUT_MULT; if (timeout > CONF_TIMEOUT_MAX) timeout = CONF_TIMEOUT_MAX; printk("."); } #ifdef IPCONFIG_BOOTP if (do_bootp) ic_bootp_cleanup(); #endif #ifdef IPCONFIG_RARP if (do_rarp) ic_rarp_cleanup(); #endif if (!ic_got_reply) { ic_myaddr = INADDR_NONE; return -1; } printk("IP-Config: Got %s answer from %u.%u.%u.%u, ", ((ic_got_reply & IC_RARP) ? "RARP" : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"), NIPQUAD(ic_servaddr)); printk("my address is %u.%u.%u.%u\n", NIPQUAD(ic_myaddr)); return 0; } #endif /* IPCONFIG_DYNAMIC */ #ifdef CONFIG_PROC_FS static int pnp_seq_show(struct seq_file *seq, void *v) { int i; if (ic_proto_used & IC_PROTO) seq_printf(seq, "#PROTO: %s\n", (ic_proto_used & IC_RARP) ? "RARP" : (ic_proto_used & IC_USE_DHCP) ? "DHCP" : "BOOTP"); else seq_puts(seq, "#MANUAL\n"); if (ic_domain[0]) seq_printf(seq, "domain %s\n", ic_domain); for (i = 0; i < CONF_NAMESERVERS_MAX; i++) { if (ic_nameservers[i] != INADDR_NONE) seq_printf(seq, "nameserver %u.%u.%u.%u\n", NIPQUAD(ic_nameservers[i])); } if (ic_servaddr != INADDR_NONE) seq_printf(seq, "bootserver %u.%u.%u.%u\n", NIPQUAD(ic_servaddr)); return 0; } static int pnp_seq_open(struct inode *indoe, struct file *file) { return single_open(file, pnp_seq_show, NULL); } static struct file_operations pnp_seq_fops = { .owner = THIS_MODULE, .open = pnp_seq_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #endif /* CONFIG_PROC_FS */ /* * Extract IP address from the parameter string if needed. Note that we * need to have root_server_addr set _before_ IPConfig gets called as it * can override it. */ u32 __init root_nfs_parse_addr(char *name) { u32 addr; int octets = 0; char *cp, *cq; cp = cq = name; while (octets < 4) { while (*cp >= '0' && *cp <= '9') cp++; if (cp == cq || cp - cq > 3) break; if (*cp == '.' || octets == 3) octets++; if (octets < 4) cp++; cq = cp; } if (octets == 4 && (*cp == ':' || *cp == '\0')) { if (*cp == ':') *cp++ = '\0'; addr = in_aton(name); memmove(name, cp, strlen(cp) + 1); } else addr = INADDR_NONE; return addr; } /* * IP Autoconfig dispatcher. */ static int __init ip_auto_config(void) { u32 addr; #ifdef CONFIG_PROC_FS proc_net_fops_create("pnp", S_IRUGO, &pnp_seq_fops); #endif /* CONFIG_PROC_FS */ if (!ic_enable) return 0; DBG(("IP-Config: Entered.\n")); #ifdef IPCONFIG_DYNAMIC try_try_again: #endif /* Give hardware a chance to settle */ msleep(CONF_PRE_OPEN); /* Setup all network devices */ if (ic_open_devs() < 0) return -1; /* Give drivers a chance to settle */ ssleep(CONF_POST_OPEN); /* * If the config information is insufficient (e.g., our IP address or * IP address of the boot server is missing or we have multiple network * interfaces and no default was set), use BOOTP or RARP to get the * missing values. */ if (ic_myaddr == INADDR_NONE || #ifdef CONFIG_ROOT_NFS (MAJOR(ROOT_DEV) == UNNAMED_MAJOR && root_server_addr == INADDR_NONE && ic_servaddr == INADDR_NONE) || #endif ic_first_dev->next) { #ifdef IPCONFIG_DYNAMIC int retries = CONF_OPEN_RETRIES; if (ic_dynamic() < 0) { ic_close_devs(); /* * I don't know why, but sometimes the * eepro100 driver (at least) gets upset and * doesn't work the first time it's opened. * But then if you close it and reopen it, it * works just fine. So we need to try that at * least once before giving up. * * Also, if the root will be NFS-mounted, we * have nowhere to go if DHCP fails. So we * just have to keep trying forever. * * -- Chip */ #ifdef CONFIG_ROOT_NFS if (ROOT_DEV == Root_NFS) { printk(KERN_ERR "IP-Config: Retrying forever (NFS root)...\n"); goto try_try_again; } #endif if (--retries) { printk(KERN_ERR "IP-Config: Reopening network devices...\n"); goto try_try_again; } /* Oh, well. At least we tried. */ printk(KERN_ERR "IP-Config: Auto-configuration of network failed.\n"); return -1; } #else /* !DYNAMIC */ printk(KERN_ERR "IP-Config: Incomplete network configuration information.\n"); ic_close_devs(); return -1; #endif /* IPCONFIG_DYNAMIC */ } else { /* Device selected manually or only one device -> use it */ ic_dev = ic_first_dev->dev; } addr = root_nfs_parse_addr(root_server_path); if (root_server_addr == INADDR_NONE) root_server_addr = addr; /* * Use defaults whereever applicable. */ if (ic_defaults() < 0) return -1; /* * Close all network devices except the device we've * autoconfigured and set up routes. */ ic_close_devs(); if (ic_setup_if() < 0 || ic_setup_routes() < 0) return -1; /* * Record which protocol was actually used. */ #ifdef IPCONFIG_DYNAMIC ic_proto_used = ic_got_reply | (ic_proto_enabled & IC_USE_DHCP); #endif #ifndef IPCONFIG_SILENT /* * Clue in the operator. */ printk("IP-Config: Complete:"); printk("\n device=%s", ic_dev->name); printk(", addr=%u.%u.%u.%u", NIPQUAD(ic_myaddr)); printk(", mask=%u.%u.%u.%u", NIPQUAD(ic_netmask)); printk(", gw=%u.%u.%u.%u", NIPQUAD(ic_gateway)); printk(",\n host=%s, domain=%s, nis-domain=%s", system_utsname.nodename, ic_domain, system_utsname.domainname); printk(",\n bootserver=%u.%u.%u.%u", NIPQUAD(ic_servaddr)); printk(", rootserver=%u.%u.%u.%u", NIPQUAD(root_server_addr)); printk(", rootpath=%s", root_server_path); printk("\n"); #endif /* !SILENT */ return 0; } late_initcall(ip_auto_config); /* * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel * command line parameter. It consists of option fields separated by colons in * the following order: * * <client-ip>:<server-ip>:<gw-ip>:<netmask>:<host name>:<device>:<PROTO> * * Any of the fields can be empty which means to use a default value: * <client-ip> - address given by BOOTP or RARP * <server-ip> - address of host returning BOOTP or RARP packet * <gw-ip> - none, or the address returned by BOOTP * <netmask> - automatically determined from <client-ip>, or the * one returned by BOOTP * <host name> - <client-ip> in ASCII notation, or the name returned * by BOOTP * <device> - use all available devices * <PROTO>: * off|none - don't do autoconfig at all (DEFAULT) * on|any - use any configured protocol * dhcp|bootp|rarp - use only the specified protocol * both - use both BOOTP and RARP (not DHCP) */ static int __init ic_proto_name(char *name) { if (!strcmp(name, "on") || !strcmp(name, "any")) { return 1; } #ifdef CONFIG_IP_PNP_DHCP else if (!strcmp(name, "dhcp")) { ic_proto_enabled &= ~IC_RARP; return 1; } #endif #ifdef CONFIG_IP_PNP_BOOTP else if (!strcmp(name, "bootp")) { ic_proto_enabled &= ~(IC_RARP | IC_USE_DHCP); return 1; } #endif #ifdef CONFIG_IP_PNP_RARP else if (!strcmp(name, "rarp")) { ic_proto_enabled &= ~(IC_BOOTP | IC_USE_DHCP); return 1; } #endif #ifdef IPCONFIG_DYNAMIC else if (!strcmp(name, "both")) { ic_proto_enabled &= ~IC_USE_DHCP; /* backward compat :-( */ return 1; } #endif return 0; } static int __init ip_auto_config_setup(char *addrs) { char *cp, *ip, *dp; int num = 0; ic_set_manually = 1; ic_enable = (*addrs && (strcmp(addrs, "off") != 0) && (strcmp(addrs, "none") != 0)); if (!ic_enable) return 1; if (ic_proto_name(addrs)) return 1; /* Parse the whole string */ ip = addrs; while (ip && *ip) { if ((cp = strchr(ip, ':'))) *cp++ = '\0'; if (strlen(ip) > 0) { DBG(("IP-Config: Parameter #%d: `%s'\n", num, ip)); switch (num) { case 0: if ((ic_myaddr = in_aton(ip)) == INADDR_ANY) ic_myaddr = INADDR_NONE; break; case 1: if ((ic_servaddr = in_aton(ip)) == INADDR_ANY) ic_servaddr = INADDR_NONE; break; case 2: if ((ic_gateway = in_aton(ip)) == INADDR_ANY) ic_gateway = INADDR_NONE; break; case 3: if ((ic_netmask = in_aton(ip)) == INADDR_ANY) ic_netmask = INADDR_NONE; break; case 4: if ((dp = strchr(ip, '.'))) { *dp++ = '\0'; strlcpy(system_utsname.domainname, dp, sizeof(system_utsname.domainname)); } strlcpy(system_utsname.nodename, ip, sizeof(system_utsname.nodename)); ic_host_name_set = 1; break; case 5: strlcpy(user_dev_name, ip, sizeof(user_dev_name)); break; case 6: ic_proto_name(ip); break; } } ip = cp; num++; } return 1; } static int __init nfsaddrs_config_setup(char *addrs) { return ip_auto_config_setup(addrs); } __setup("ip=", ip_auto_config_setup); __setup("nfsaddrs=", nfsaddrs_config_setup);