// SPDX-License-Identifier: GPL-2.0 /* * 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 * * 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 , 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 , May 2000 * * Ported DHCP support from 2.2.16 to 2.4.0-test4 * -- Eric Biederman , 30 Aug 2000 * * Merged changes from 2.2.19 into 2.4.3 * -- Eric Biederman , 22 April Aug 2001 * * Multiple Nameservers in /proc/net/pnp * -- Josef Siemes , Aug 2002 * * NTP servers in /proc/net/ipconfig/ntp_servers * -- Chris Novakovic , April 2018 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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_POST_OPEN 10 /* After opening: 10 msecs */ /* 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_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 */ #define CONF_NTP_SERVERS_MAX 3 /* Maximum number of NTP servers */ #define NONE cpu_to_be32(INADDR_NONE) #define ANY cpu_to_be32(INADDR_ANY) /* Wait for carrier timeout default in seconds */ static unsigned int carrier_timeout = 120; /* * 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; /* 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; /* Host name set by us? */ __be32 ic_myaddr = NONE; /* My IP address */ static __be32 ic_netmask = NONE; /* Netmask for local subnet */ __be32 ic_gateway = NONE; /* Gateway IP address */ #ifdef IPCONFIG_DYNAMIC static __be32 ic_addrservaddr = NONE; /* IP Address of the IP addresses'server */ #endif __be32 ic_servaddr = NONE; /* Boot server IP address */ __be32 root_server_addr = NONE; /* Address of NFS server */ u8 root_server_path[256] = { 0, }; /* Path to mount as root */ /* vendor class identifier */ static char vendor_class_identifier[253] __initdata; #if defined(CONFIG_IP_PNP_DHCP) static char dhcp_client_identifier[253] __initdata; #endif /* Persistent data: */ #ifdef IPCONFIG_DYNAMIC static int ic_proto_used; /* Protocol used, if any */ #else #define ic_proto_used 0 #endif static __be32 ic_nameservers[CONF_NAMESERVERS_MAX]; /* DNS Server IP addresses */ static __be32 ic_ntp_servers[CONF_NTP_SERVERS_MAX]; /* NTP 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; /* MTU for boot device */ static int ic_dev_mtu __initdata; /* DHCPACK can overwrite DNS if fallback was set upon first BOOTP reply */ static int ic_nameservers_fallback __initdata; #ifdef IPCONFIG_DYNAMIC static DEFINE_SPINLOCK(ic_recv_lock); static volatile int ic_got_reply __initdata; /* Proto(s) that replied */ #endif #ifdef IPCONFIG_DHCP static int ic_dhcp_msgtype __initdata; /* DHCP msg type received */ #endif /* * Network devices */ struct ic_device { struct ic_device *next; struct net_device *dev; unsigned short flags; short able; __be32 xid; }; static struct ic_device *ic_first_dev __initdata; /* List of open device */ static struct ic_device *ic_dev __initdata; /* Selected device */ static bool __init ic_is_init_dev(struct net_device *dev) { if (dev->flags & IFF_LOOPBACK) return false; return 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)); } static int __init ic_open_devs(void) { struct ic_device *d, **last; struct net_device *dev; unsigned short oflags; unsigned long start, next_msg; last = &ic_first_dev; rtnl_lock(); /* bring loopback device up first */ for_each_netdev(&init_net, dev) { if (!(dev->flags & IFF_LOOPBACK)) continue; if (dev_change_flags(dev, dev->flags | IFF_UP, NULL) < 0) pr_err("IP-Config: Failed to open %s\n", dev->name); } for_each_netdev(&init_net, dev) { if (ic_is_init_dev(dev)) { int able = 0; if (dev->mtu >= 364) able |= IC_BOOTP; else pr_warn("DHCP/BOOTP: Ignoring device %s, MTU %d too small\n", 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, NULL) < 0) { pr_err("IP-Config: Failed to open %s\n", dev->name); continue; } if (!(d = kmalloc(sizeof(struct ic_device), GFP_KERNEL))) { rtnl_unlock(); return -ENOMEM; } d->dev = dev; *last = d; last = &d->next; d->flags = oflags; d->able = able; if (able & IC_BOOTP) get_random_bytes(&d->xid, sizeof(__be32)); else d->xid = 0; ic_proto_have_if |= able; pr_debug("IP-Config: %s UP (able=%d, xid=%08x)\n", dev->name, able, d->xid); } } /* Devices with a complex topology like SFP ethernet interfaces needs * the rtnl_lock at init. The carrier wait-loop must therefore run * without holding it. */ rtnl_unlock(); /* no point in waiting if we could not bring up at least one device */ if (!ic_first_dev) goto have_carrier; /* wait for a carrier on at least one device */ start = jiffies; next_msg = start + msecs_to_jiffies(20000); while (time_before(jiffies, start + msecs_to_jiffies(carrier_timeout * 1000))) { int wait, elapsed; rtnl_lock(); for_each_netdev(&init_net, dev) if (ic_is_init_dev(dev) && netif_carrier_ok(dev)) { rtnl_unlock(); goto have_carrier; } rtnl_unlock(); msleep(1); if (time_before(jiffies, next_msg)) continue; elapsed = jiffies_to_msecs(jiffies - start); wait = (carrier_timeout * 1000 - elapsed + 500) / 1000; pr_info("Waiting up to %d more seconds for network.\n", wait); next_msg = jiffies + msecs_to_jiffies(20000); } have_carrier: *last = NULL; if (!ic_first_dev) { if (user_dev_name[0]) pr_err("IP-Config: Device `%s' not found\n", user_dev_name); else pr_err("IP-Config: No network devices available\n"); return -ENODEV; } return 0; } /* Close all network interfaces except the one we've autoconfigured, and its * lowers, in case it's a stacked virtual interface. */ static void __init ic_close_devs(void) { struct net_device *selected_dev = ic_dev ? ic_dev->dev : NULL; struct ic_device *d, *next; struct net_device *dev; rtnl_lock(); next = ic_first_dev; while ((d = next)) { bool bring_down = (d != ic_dev); struct net_device *lower; struct list_head *iter; next = d->next; dev = d->dev; if (selected_dev) { netdev_for_each_lower_dev(selected_dev, lower, iter) { if (dev == lower) { bring_down = false; break; } } } if (bring_down) { pr_debug("IP-Config: Downing %s\n", dev->name); dev_change_flags(dev, d->flags, NULL); } kfree(d); } rtnl_unlock(); } /* * Interface to various network functions. */ static inline void set_sockaddr(struct sockaddr_in *sin, __be32 addr, __be16 port) { sin->sin_family = AF_INET; sin->sin_addr.s_addr = addr; sin->sin_port = port; } /* * 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->dev->name); set_sockaddr(sin, ic_myaddr, 0); if ((err = devinet_ioctl(&init_net, SIOCSIFADDR, &ir)) < 0) { pr_err("IP-Config: Unable to set interface address (%d)\n", err); return -1; } set_sockaddr(sin, ic_netmask, 0); if ((err = devinet_ioctl(&init_net, SIOCSIFNETMASK, &ir)) < 0) { pr_err("IP-Config: Unable to set interface netmask (%d)\n", err); return -1; } set_sockaddr(sin, ic_myaddr | ~ic_netmask, 0); if ((err = devinet_ioctl(&init_net, SIOCSIFBRDADDR, &ir)) < 0) { pr_err("IP-Config: Unable to set interface broadcast address (%d)\n", err); return -1; } /* Handle the case where we need non-standard MTU on the boot link (a network * using jumbo frames, for instance). If we can't set the mtu, don't error * out, we'll try to muddle along. */ if (ic_dev_mtu != 0) { rtnl_lock(); if ((err = dev_set_mtu(ic_dev->dev, ic_dev_mtu)) < 0) pr_err("IP-Config: Unable to set interface mtu to %d (%d)\n", ic_dev_mtu, err); rtnl_unlock(); } return 0; } static int __init ic_setup_routes(void) { /* No need to setup device routes, only the default route... */ if (ic_gateway != NONE) { struct rtentry rm; int err; memset(&rm, 0, sizeof(rm)); if ((ic_gateway ^ ic_myaddr) & ic_netmask) { pr_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 = ip_rt_ioctl(&init_net, SIOCADDRT, &rm)) < 0) { pr_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(init_utsname()->nodename, "%pI4", &ic_myaddr); if (root_server_addr == NONE) root_server_addr = ic_servaddr; if (ic_netmask == 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 if (IN_CLASSE(ntohl(ic_myaddr))) ic_netmask = htonl(IN_CLASSE_NET); else { pr_err("IP-Config: Unable to guess netmask for address %pI4\n", &ic_myaddr); return -1; } pr_notice("IP-Config: Guessing netmask %pI4\n", &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 = cpu_to_be16(ETH_P_RARP), .func = ic_rarp_recv, }; static inline void __init ic_rarp_init(void) { dev_add_pack(&rarp_packet_type); } static inline void __init 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; __be32 sip, tip; unsigned char *tha; /* t for "target" */ struct ic_device *d; if (!net_eq(dev_net(dev), &init_net)) goto drop; skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) 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_transport_header(skb); /* 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, arp_hdr_len(dev))) goto drop; /* OK, it is all there and looks valid, process... */ rarp = (struct arphdr *)skb_transport_header(skb); 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 */ 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 != NONE && ic_servaddr != sip) goto drop_unlock; /* We have a winner! */ ic_dev = d; if (ic_myaddr == NONE) ic_myaddr = tip; ic_servaddr = sip; ic_addrservaddr = 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 /* * Predefine Nameservers */ static inline void __init ic_nameservers_predef(void) { int i; for (i = 0; i < CONF_NAMESERVERS_MAX; i++) ic_nameservers[i] = NONE; } /* Predefine NTP servers */ static inline void __init ic_ntp_servers_predef(void) { int i; for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) ic_ntp_servers[i] = NONE; } /* * 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 */ __be32 xid; /* Transaction ID */ __be16 secs; /* Seconds since we started */ __be16 flags; /* Just what it says */ __be32 client_ip; /* Client's IP address if known */ __be32 your_ip; /* Assigned IP address */ __be32 server_ip; /* (Next, e.g. NFS) Server's IP address */ __be32 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 = cpu_to_be16(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, struct ic_device *d) { u8 mt = ((ic_servaddr == NONE) ? DHCPDISCOVER : DHCPREQUEST); u8 *e = options; int len; pr_debug("DHCP: Sending message type %d (%s)\n", mt, d->dev->name); 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 */ 26, /* MTU */ 40, /* NIS domain name */ 42, /* NTP servers */ }; *e++ = 55; /* Parameter request list */ *e++ = sizeof(ic_req_params); memcpy(e, ic_req_params, sizeof(ic_req_params)); e += sizeof(ic_req_params); if (ic_host_name_set) { *e++ = 12; /* host-name */ len = strlen(utsname()->nodename); *e++ = len; memcpy(e, utsname()->nodename, len); e += len; } if (*vendor_class_identifier) { pr_info("DHCP: sending class identifier \"%s\"\n", vendor_class_identifier); *e++ = 60; /* Class-identifier */ len = strlen(vendor_class_identifier); *e++ = len; memcpy(e, vendor_class_identifier, len); e += len; } len = strlen(dhcp_client_identifier + 1); /* the minimum length of identifier is 2, include 1 byte type, * and can not be larger than the length of options */ if (len >= 1 && len < 312 - (e - options) - 1) { *e++ = 61; *e++ = len + 1; memcpy(e, dhcp_client_identifier, len + 1); e += len + 1; } } *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; #if CONF_NAMESERVERS_MAX > 0 *e++ = 6; /* (DNS) name server request */ *e++ = 4 * CONF_NAMESERVERS_MAX; e += 4 * CONF_NAMESERVERS_MAX; #endif *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 __init ic_bootp_init(void) { /* Re-initialise all name servers and NTP servers to NONE, in case any * were set via the "ip=" or "nfsaddrs=" kernel command line parameters: * any IP addresses specified there will already have been decoded but * are no longer needed */ ic_nameservers_predef(); ic_ntp_servers_predef(); dev_add_pack(&bootp_packet_type); } /* * DHCP/BOOTP cleanup. */ static inline void __init 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; struct iphdr *h; int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; /* Allocate packet */ skb = alloc_skb(sizeof(struct bootp_pkt) + hlen + tlen + 15, GFP_KERNEL); if (!skb) return; skb_reserve(skb, hlen); b = skb_put_zero(skb, sizeof(struct bootp_pkt)); /* Construct IP header */ skb_reset_network_header(skb); h = ip_hdr(skb); 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 = htonl(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_FDDI) b->htype = ARPHRD_ETHER; else { pr_warn("Unknown ARP type 0x%04x for device %s\n", dev->type, dev->name); b->htype = dev->type; /* can cause undefined behavior */ } /* server_ip and your_ip address are both already zero per RFC2131 */ b->hlen = dev->addr_len; 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, d); 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(skb, dev, ntohs(skb->protocol), dev->broadcast, dev->dev_addr, skb->len) < 0) { kfree_skb(skb); printk("E"); return; } if (dev_queue_xmit(skb) < 0) printk("E"); } /* * Copy BOOTP-supplied string */ 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; __be16 mtu; u8 *c; pr_debug("DHCP/BOOTP: Got extension %d:", *ext); for (c=ext+2; c CONF_NAMESERVERS_MAX) servers = CONF_NAMESERVERS_MAX; for (i = 0; i < servers; i++) { if (ic_nameservers[i] == NONE || ic_nameservers_fallback) memcpy(&ic_nameservers[i], ext+1+4*i, 4); } break; case 12: /* Host name */ if (!ic_host_name_set) { ic_bootp_string(utsname()->nodename, ext+1, *ext, __NEW_UTS_LEN); ic_host_name_set = 1; } break; case 15: /* Domain name (DNS) */ if (!ic_domain[0]) 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 26: /* Interface MTU */ memcpy(&mtu, ext+1, sizeof(mtu)); ic_dev_mtu = ntohs(mtu); break; case 40: /* NIS Domain name (_not_ DNS) */ ic_bootp_string(utsname()->domainname, ext+1, *ext, __NEW_UTS_LEN); break; case 42: /* NTP servers */ servers = *ext / 4; if (servers > CONF_NTP_SERVERS_MAX) servers = CONF_NTP_SERVERS_MAX; for (i = 0; i < servers; i++) { if (ic_ntp_servers[i] == NONE) memcpy(&ic_ntp_servers[i], ext+1+4*i, 4); } 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; if (!net_eq(dev_net(dev), &init_net)) goto drop; /* Perform verifications before taking the lock. */ if (skb->pkt_type == PACKET_OTHERHOST) goto drop; skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) return NET_RX_DROP; if (!pskb_may_pull(skb, sizeof(struct iphdr) + sizeof(struct udphdr))) goto drop; b = (struct bootp_pkt *)skb_network_header(skb); h = &b->iph; if (h->ihl != 5 || h->version != 4 || h->protocol != IPPROTO_UDP) goto drop; /* Fragments are not supported */ if (ip_is_fragment(h)) { net_err_ratelimited("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_network_header(skb); 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) { net_err_ratelimited("DHCP/BOOTP: Reply not for us on %s, op[%x] xid[%x]\n", d->dev->name, 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) { __be32 server_id = 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; } } pr_debug("DHCP: Got message type %d (%s)\n", mt, d->dev->name); switch (mt) { case DHCPOFFER: /* While in the process of accepting one offer, * ignore all others. */ if (ic_myaddr != NONE) goto drop_unlock; /* Let's accept that offer. */ ic_myaddr = b->your_ip; ic_servaddr = server_id; pr_debug("DHCP: Offered address %pI4 by server %pI4\n", &ic_myaddr, &b->iph.saddr); /* The DHCP indicated server address takes * precedence over the bootp header one if * they are different. */ if ((server_id != 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 = NONE; ic_servaddr = 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 = d; ic_myaddr = b->your_ip; ic_servaddr = b->server_ip; ic_addrservaddr = b->iph.saddr; if (ic_gateway == NONE && b->relay_ip) ic_gateway = b->relay_ip; if (ic_nameservers[0] == NONE) { ic_nameservers[0] = ic_servaddr; ic_nameservers_fallback = 1; } 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) { pr_err("IP-Config: Incomplete network configuration information\n"); return -1; } #ifdef IPCONFIG_BOOTP if ((ic_proto_enabled ^ ic_proto_have_if) & IC_BOOTP) pr_err("DHCP/BOOTP: No suitable device found\n"); #endif #ifdef IPCONFIG_RARP if ((ic_proto_enabled ^ ic_proto_have_if) & IC_RARP) pr_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] */ pr_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 int) 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 if (!d->next) { jiff = jiffies + timeout; while (time_before(jiffies, jiff) && !ic_got_reply) schedule_timeout_uninterruptible(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; /* continue on device that got the reply */ d = ic_dev; pr_cont(","); continue; } #endif /* IPCONFIG_DHCP */ if (ic_got_reply) { pr_cont(" OK\n"); break; } if ((d = d->next)) continue; if (! --retries) { pr_cont(" timed out!\n"); break; } d = ic_first_dev; timeout = timeout CONF_TIMEOUT_MULT; if (timeout > CONF_TIMEOUT_MAX) timeout = CONF_TIMEOUT_MAX; pr_cont("."); } #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 = NONE; return -1; } pr_info("IP-Config: Got %s answer from %pI4, my address is %pI4\n", ((ic_got_reply & IC_RARP) ? "RARP" : (ic_proto_enabled & IC_USE_DHCP) ? "DHCP" : "BOOTP"), &ic_addrservaddr, &ic_myaddr); return 0; } #endif /* IPCONFIG_DYNAMIC */ #ifdef CONFIG_PROC_FS /* proc_dir_entry for /proc/net/ipconfig */ static struct proc_dir_entry *ipconfig_dir; /* Name servers: */ 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] != NONE) seq_printf(seq, "nameserver %pI4\n", &ic_nameservers[i]); } if (ic_servaddr != NONE) seq_printf(seq, "bootserver %pI4\n", &ic_servaddr); return 0; } /* Create the /proc/net/ipconfig directory */ static int __init ipconfig_proc_net_init(void) { ipconfig_dir = proc_net_mkdir(&init_net, "ipconfig", init_net.proc_net); if (!ipconfig_dir) return -ENOMEM; return 0; } /* Create a new file under /proc/net/ipconfig */ static int ipconfig_proc_net_create(const char *name, const struct proc_ops *proc_ops) { char *pname; struct proc_dir_entry *p; if (!ipconfig_dir) return -ENOMEM; pname = kasprintf(GFP_KERNEL, "%s%s", "ipconfig/", name); if (!pname) return -ENOMEM; p = proc_create(pname, 0444, init_net.proc_net, proc_ops); kfree(pname); if (!p) return -ENOMEM; return 0; } /* Write NTP server IP addresses to /proc/net/ipconfig/ntp_servers */ static int ntp_servers_show(struct seq_file *seq, void *v) { int i; for (i = 0; i < CONF_NTP_SERVERS_MAX; i++) { if (ic_ntp_servers[i] != NONE) seq_printf(seq, "%pI4\n", &ic_ntp_servers[i]); } return 0; } DEFINE_PROC_SHOW_ATTRIBUTE(ntp_servers); #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. */ __be32 __init root_nfs_parse_addr(char *name) { __be32 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 = NONE; return addr; } #define DEVICE_WAIT_MAX 12 /* 12 seconds */ static int __init wait_for_devices(void) { int i; bool try_init_devs = true; for (i = 0; i < DEVICE_WAIT_MAX; i++) { struct net_device *dev; int found = 0; /* make sure deferred device probes are finished */ wait_for_device_probe(); rtnl_lock(); for_each_netdev(&init_net, dev) { if (ic_is_init_dev(dev)) { found = 1; break; } } rtnl_unlock(); if (found) return 0; if (try_init_devs && (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) { try_init_devs = false; wait_for_init_devices_probe(); } ssleep(1); } return -ENODEV; } /* * IP Autoconfig dispatcher. */ static int __init ip_auto_config(void) { __be32 addr; #ifdef IPCONFIG_DYNAMIC int retries = CONF_OPEN_RETRIES; #endif int err; unsigned int i, count; /* Initialise all name servers and NTP servers to NONE (but only if the * "ip=" or "nfsaddrs=" kernel command line parameters weren't decoded, * otherwise we'll overwrite the IP addresses specified there) */ if (ic_set_manually == 0) { ic_nameservers_predef(); ic_ntp_servers_predef(); } #ifdef CONFIG_PROC_FS proc_create_single("pnp", 0444, init_net.proc_net, pnp_seq_show); if (ipconfig_proc_net_init() == 0) ipconfig_proc_net_create("ntp_servers", &ntp_servers_proc_ops); #endif /* CONFIG_PROC_FS */ if (!ic_enable) return 0; pr_debug("IP-Config: Entered.\n"); #ifdef IPCONFIG_DYNAMIC try_try_again: #endif /* Wait for devices to appear */ err = wait_for_devices(); if (err) return err; /* Setup all network devices */ err = ic_open_devs(); if (err) return err; /* Give drivers a chance to settle */ msleep(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 == NONE || #if defined(CONFIG_ROOT_NFS) || defined(CONFIG_CIFS_ROOT) (root_server_addr == NONE && ic_servaddr == NONE && (ROOT_DEV == Root_NFS || ROOT_DEV == Root_CIFS)) || #endif ic_first_dev->next) { #ifdef IPCONFIG_DYNAMIC 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) { pr_err("IP-Config: Retrying forever (NFS root)...\n"); goto try_try_again; } #endif #ifdef CONFIG_CIFS_ROOT if (ROOT_DEV == Root_CIFS) { pr_err("IP-Config: Retrying forever (CIFS root)...\n"); goto try_try_again; } #endif if (--retries) { pr_err("IP-Config: Reopening network devices...\n"); goto try_try_again; } /* Oh, well. At least we tried. */ pr_err("IP-Config: Auto-configuration of network failed\n"); return -1; } #else /* !DYNAMIC */ pr_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; } addr = root_nfs_parse_addr(root_server_path); if (root_server_addr == NONE) root_server_addr = addr; /* * Use defaults wherever applicable. */ if (ic_defaults() < 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. */ pr_info("IP-Config: Complete:\n"); pr_info(" device=%s, hwaddr=%*phC, ipaddr=%pI4, mask=%pI4, gw=%pI4\n", ic_dev->dev->name, ic_dev->dev->addr_len, ic_dev->dev->dev_addr, &ic_myaddr, &ic_netmask, &ic_gateway); pr_info(" host=%s, domain=%s, nis-domain=%s\n", utsname()->nodename, ic_domain, utsname()->domainname); pr_info(" bootserver=%pI4, rootserver=%pI4, rootpath=%s", &ic_servaddr, &root_server_addr, root_server_path); if (ic_dev_mtu) pr_cont(", mtu=%d", ic_dev_mtu); /* Name servers (if any): */ for (i = 0, count = 0; i < CONF_NAMESERVERS_MAX; i++) { if (ic_nameservers[i] != NONE) { if (i == 0) pr_info(" nameserver%u=%pI4", i, &ic_nameservers[i]); else pr_cont(", nameserver%u=%pI4", i, &ic_nameservers[i]); count++; } if ((i + 1 == CONF_NAMESERVERS_MAX) && count > 0) pr_cont("\n"); } /* NTP servers (if any): */ for (i = 0, count = 0; i < CONF_NTP_SERVERS_MAX; i++) { if (ic_ntp_servers[i] != NONE) { if (i == 0) pr_info(" ntpserver%u=%pI4", i, &ic_ntp_servers[i]); else pr_cont(", ntpserver%u=%pI4", i, &ic_ntp_servers[i]); count++; } if ((i + 1 == CONF_NTP_SERVERS_MAX) && count > 0) pr_cont("\n"); } #endif /* !SILENT */ /* * Close all network devices except the device we've * autoconfigured and set up routes. */ if (ic_setup_if() < 0 || ic_setup_routes() < 0) err = -1; else err = 0; ic_close_devs(); return err; } late_initcall(ip_auto_config); /* * Decode any IP configuration options in the "ip=" or "nfsaddrs=" kernel * command line parameter. See Documentation/admin-guide/nfs/nfsroot.rst. */ static int __init ic_proto_name(char *name) { if (!strcmp(name, "on") || !strcmp(name, "any")) { return 1; } if (!strcmp(name, "off") || !strcmp(name, "none")) { return 0; } #ifdef CONFIG_IP_PNP_DHCP else if (!strncmp(name, "dhcp", 4)) { char *client_id; ic_proto_enabled &= ~IC_RARP; client_id = strstr(name, "dhcp,"); if (client_id) { char *v; client_id = client_id + 5; v = strchr(client_id, ','); if (!v) return 1; *v = 0; if (kstrtou8(client_id, 0, dhcp_client_identifier)) pr_debug("DHCP: Invalid client identifier type\n"); strncpy(dhcp_client_identifier + 1, v + 1, 251); *v = ','; } 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 = 1; /* * If any dhcp, bootp etc options are set, leave autoconfig on * and skip the below static IP processing. */ if (ic_proto_name(addrs)) return 1; /* If no static IP is given, turn off autoconfig and bail. */ if (*addrs == 0 || strcmp(addrs, "off") == 0 || strcmp(addrs, "none") == 0) { ic_enable = 0; return 1; } /* Initialise all name servers and NTP servers to NONE */ ic_nameservers_predef(); ic_ntp_servers_predef(); /* Parse string for static IP assignment. */ ip = addrs; while (ip && *ip) { if ((cp = strchr(ip, ':'))) *cp++ = '\0'; if (strlen(ip) > 0) { pr_debug("IP-Config: Parameter #%d: `%s'\n", num, ip); switch (num) { case 0: if ((ic_myaddr = in_aton(ip)) == ANY) ic_myaddr = NONE; break; case 1: if ((ic_servaddr = in_aton(ip)) == ANY) ic_servaddr = NONE; break; case 2: if ((ic_gateway = in_aton(ip)) == ANY) ic_gateway = NONE; break; case 3: if ((ic_netmask = in_aton(ip)) == ANY) ic_netmask = NONE; break; case 4: if ((dp = strchr(ip, '.'))) { *dp++ = '\0'; strscpy(utsname()->domainname, dp, sizeof(utsname()->domainname)); } strscpy(utsname()->nodename, ip, sizeof(utsname()->nodename)); ic_host_name_set = 1; break; case 5: strscpy(user_dev_name, ip, sizeof(user_dev_name)); break; case 6: if (ic_proto_name(ip) == 0 && ic_myaddr == NONE) { ic_enable = 0; } break; case 7: if (CONF_NAMESERVERS_MAX >= 1) { ic_nameservers[0] = in_aton(ip); if (ic_nameservers[0] == ANY) ic_nameservers[0] = NONE; } break; case 8: if (CONF_NAMESERVERS_MAX >= 2) { ic_nameservers[1] = in_aton(ip); if (ic_nameservers[1] == ANY) ic_nameservers[1] = NONE; } break; case 9: if (CONF_NTP_SERVERS_MAX >= 1) { ic_ntp_servers[0] = in_aton(ip); if (ic_ntp_servers[0] == ANY) ic_ntp_servers[0] = NONE; } break; } } ip = cp; num++; } return 1; } __setup("ip=", ip_auto_config_setup); static int __init nfsaddrs_config_setup(char *addrs) { return ip_auto_config_setup(addrs); } __setup("nfsaddrs=", nfsaddrs_config_setup); static int __init vendor_class_identifier_setup(char *addrs) { if (strscpy(vendor_class_identifier, addrs, sizeof(vendor_class_identifier)) >= sizeof(vendor_class_identifier)) pr_warn("DHCP: vendorclass too long, truncated to \"%s\"\n", vendor_class_identifier); return 1; } __setup("dhcpclass=", vendor_class_identifier_setup); static int __init set_carrier_timeout(char *str) { ssize_t ret; if (!str) return 0; ret = kstrtouint(str, 0, &carrier_timeout); if (ret) return 0; return 1; } __setup("carrier_timeout=", set_carrier_timeout);