From 9fd51e9b0ad33a89a83fdbbb66bd20d85f7893fb Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Fri, 4 Feb 2000 03:21:18 +0000 Subject: Import of Linux 2.2.12 subset (ipv4 stack and related) --- pfinet/linux-src/net/ipv4/arp.c | 1154 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 1154 insertions(+) create mode 100644 pfinet/linux-src/net/ipv4/arp.c (limited to 'pfinet/linux-src/net/ipv4/arp.c') diff --git a/pfinet/linux-src/net/ipv4/arp.c b/pfinet/linux-src/net/ipv4/arp.c new file mode 100644 index 00000000..27d2f802 --- /dev/null +++ b/pfinet/linux-src/net/ipv4/arp.c @@ -0,0 +1,1154 @@ +/* linux/net/inet/arp.c + * + * Version: $Id: arp.c,v 1.77.2.1 1999/06/28 10:39:23 davem Exp $ + * + * Copyright (C) 1994 by Florian La Roche + * + * This module implements the Address Resolution Protocol ARP (RFC 826), + * which is used to convert IP addresses (or in the future maybe other + * high-level addresses) into a low-level hardware address (like an Ethernet + * address). + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + * Fixes: + * Alan Cox : Removed the Ethernet assumptions in + * Florian's code + * Alan Cox : Fixed some small errors in the ARP + * logic + * Alan Cox : Allow >4K in /proc + * Alan Cox : Make ARP add its own protocol entry + * Ross Martin : Rewrote arp_rcv() and arp_get_info() + * Stephen Henson : Add AX25 support to arp_get_info() + * Alan Cox : Drop data when a device is downed. + * Alan Cox : Use init_timer(). + * Alan Cox : Double lock fixes. + * Martin Seine : Move the arphdr structure + * to if_arp.h for compatibility. + * with BSD based programs. + * Andrew Tridgell : Added ARP netmask code and + * re-arranged proxy handling. + * Alan Cox : Changed to use notifiers. + * Niibe Yutaka : Reply for this device or proxies only. + * Alan Cox : Don't proxy across hardware types! + * Jonathan Naylor : Added support for NET/ROM. + * Mike Shaver : RFC1122 checks. + * Jonathan Naylor : Only lookup the hardware address for + * the correct hardware type. + * Germano Caronni : Assorted subtle races. + * Craig Schlenter : Don't modify permanent entry + * during arp_rcv. + * Russ Nelson : Tidied up a few bits. + * Alexey Kuznetsov: Major changes to caching and behaviour, + * eg intelligent arp probing and + * generation + * of host down events. + * Alan Cox : Missing unlock in device events. + * Eckes : ARP ioctl control errors. + * Alexey Kuznetsov: Arp free fix. + * Manuel Rodriguez: Gratuitous ARP. + * Jonathan Layes : Added arpd support through kerneld + * message queue (960314) + * Mike Shaver : /proc/sys/net/ipv4/arp_* support + * Mike McLagan : Routing by source + * Stuart Cheshire : Metricom and grat arp fixes + * *** FOR 2.1 clean this up *** + * Lawrence V. Stefani: (08/12/96) Added FDDI support. + * Alan Cox : Took the AP1000 nasty FDDI hack and + * folded into the mainstream FDDI code. + * Ack spit, Linus how did you allow that + * one in... + * Jes Sorensen : Make FDDI work again in 2.1.x and + * clean up the APFDDI & gen. FDDI bits. + * Alexey Kuznetsov: new arp state machine; + * now it is in net/core/neighbour.c. + */ + +/* RFC1122 Status: + 2.3.2.1 (ARP Cache Validation): + MUST provide mechanism to flush stale cache entries (OK) + SHOULD be able to configure cache timeout (OK) + MUST throttle ARP retransmits (OK) + 2.3.2.2 (ARP Packet Queue): + SHOULD save at least one packet from each "conversation" with an + unresolved IP address. (OK) + 950727 -- MS +*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_SYSCTL +#include +#endif + +#include +#include +#include +#include +#include +#include +#include +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) +#include +#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) +#include +#endif +#endif + +#include +#include + +/* + * Interface to generic neighbour cache. + */ +static int arp_constructor(struct neighbour *neigh); +static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb); +static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb); +static void parp_redo(struct sk_buff *skb); + +static struct neigh_ops arp_generic_ops = +{ + AF_INET, + NULL, + arp_solicit, + arp_error_report, + neigh_resolve_output, + neigh_connected_output, + dev_queue_xmit, + dev_queue_xmit +}; + +static struct neigh_ops arp_hh_ops = +{ + AF_INET, + NULL, + arp_solicit, + arp_error_report, + neigh_resolve_output, + neigh_resolve_output, + dev_queue_xmit, + dev_queue_xmit +}; + +static struct neigh_ops arp_direct_ops = +{ + AF_INET, + NULL, + NULL, + NULL, + dev_queue_xmit, + dev_queue_xmit, + dev_queue_xmit, + dev_queue_xmit +}; + +struct neigh_ops arp_broken_ops = +{ + AF_INET, + NULL, + arp_solicit, + arp_error_report, + neigh_compat_output, + neigh_compat_output, + dev_queue_xmit, + dev_queue_xmit, +}; + +struct neigh_table arp_tbl = +{ + NULL, + AF_INET, + sizeof(struct neighbour) + 4, + 4, + arp_constructor, + NULL, + NULL, + parp_redo, + { NULL, NULL, &arp_tbl, 0, NULL, NULL, + 30*HZ, 1*HZ, 60*HZ, 30*HZ, 5*HZ, 3, 3, 0, 3, 1*HZ, (8*HZ)/10, 64, 1*HZ }, + 30*HZ, 128, 512, 1024, +}; + +int arp_mc_map(u32 addr, u8 *haddr, struct device *dev, int dir) +{ + switch (dev->type) { + case ARPHRD_ETHER: + case ARPHRD_IEEE802: + case ARPHRD_FDDI: + ip_eth_mc_map(addr, haddr); + return 0; + default: + if (dir) { + memcpy(haddr, dev->broadcast, dev->addr_len); + return 0; + } + } + return -EINVAL; +} + + + +static int arp_constructor(struct neighbour *neigh) +{ + u32 addr = *(u32*)neigh->primary_key; + struct device *dev = neigh->dev; + struct in_device *in_dev = dev->ip_ptr; + + if (in_dev == NULL) + return -EINVAL; + + neigh->type = inet_addr_type(addr); + if (in_dev->arp_parms) + neigh->parms = in_dev->arp_parms; + + if (dev->hard_header == NULL) { + neigh->nud_state = NUD_NOARP; + neigh->ops = &arp_direct_ops; + neigh->output = neigh->ops->queue_xmit; + } else { + /* Good devices (checked by reading texts, but only Ethernet is + tested) + + ARPHRD_ETHER: (ethernet, apfddi) + ARPHRD_FDDI: (fddi) + ARPHRD_IEEE802: (tr) + ARPHRD_METRICOM: (strip) + ARPHRD_ARCNET: + etc. etc. etc. + + ARPHRD_IPDDP will also work, if author repairs it. + I did not it, because this driver does not work even + in old paradigm. + */ + +#if 1 + /* So... these "amateur" devices are hopeless. + The only thing, that I can say now: + It is very sad that we need to keep ugly obsolete + code to make them happy. + + They should be moved to more reasonable state, now + they use rebuild_header INSTEAD OF hard_start_xmit!!! + Besides that, they are sort of out of date + (a lot of redundant clones/copies, useless in 2.1), + I wonder why people believe that they work. + */ + switch (dev->type) { + default: + break; + case ARPHRD_ROSE: +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) + case ARPHRD_AX25: +#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) + case ARPHRD_NETROM: +#endif + neigh->ops = &arp_broken_ops; + neigh->output = neigh->ops->output; + return 0; +#endif + } +#endif + if (neigh->type == RTN_MULTICAST) { + neigh->nud_state = NUD_NOARP; + arp_mc_map(addr, neigh->ha, dev, 1); + } else if (dev->flags&(IFF_NOARP|IFF_LOOPBACK)) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->dev_addr, dev->addr_len); + } else if (neigh->type == RTN_BROADCAST || dev->flags&IFF_POINTOPOINT) { + neigh->nud_state = NUD_NOARP; + memcpy(neigh->ha, dev->broadcast, dev->addr_len); + } + if (dev->hard_header_cache) + neigh->ops = &arp_hh_ops; + else + neigh->ops = &arp_generic_ops; + if (neigh->nud_state&NUD_VALID) + neigh->output = neigh->ops->connected_output; + else + neigh->output = neigh->ops->output; + } + + return 0; +} + +static void arp_error_report(struct neighbour *neigh, struct sk_buff *skb) +{ + dst_link_failure(skb); + kfree_skb(skb); +} + +static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb) +{ + u32 saddr; + u8 *dst_ha = NULL; + struct device *dev = neigh->dev; + u32 target = *(u32*)neigh->primary_key; + int probes = neigh->probes; + + if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) + saddr = skb->nh.iph->saddr; + else + saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); + + if ((probes -= neigh->parms->ucast_probes) < 0) { + if (!(neigh->nud_state&NUD_VALID)) + printk(KERN_DEBUG "trying to ucast probe in NUD_INVALID\n"); + dst_ha = neigh->ha; + } else if ((probes -= neigh->parms->app_probes) < 0) { +#ifdef CONFIG_ARPD + neigh_app_ns(neigh); +#endif + return; + } + + arp_send(ARPOP_REQUEST, ETH_P_ARP, target, dev, saddr, + dst_ha, dev->dev_addr, NULL); +} + +/* OBSOLETE FUNCTIONS */ + +/* + * Find an arp mapping in the cache. If not found, post a request. + * + * It is very UGLY routine: it DOES NOT use skb->dst->neighbour, + * even if it exists. It is supposed that skb->dev was mangled + * by a virtual device (eql, shaper). Nobody but broken devices + * is allowed to use this function, it is scheduled to be removed. --ANK + */ + +static int arp_set_predefined(int addr_hint, unsigned char * haddr, u32 paddr, struct device * dev) +{ + switch (addr_hint) { + case RTN_LOCAL: + printk(KERN_DEBUG "ARP: arp called for own IP address\n"); + memcpy(haddr, dev->dev_addr, dev->addr_len); + return 1; + case RTN_MULTICAST: + arp_mc_map(paddr, haddr, dev, 1); + return 1; + case RTN_BROADCAST: + memcpy(haddr, dev->broadcast, dev->addr_len); + return 1; + } + return 0; +} + + +int arp_find(unsigned char *haddr, struct sk_buff *skb) +{ + struct device *dev = skb->dev; + u32 paddr; + struct neighbour *n; + + if (!skb->dst) { + printk(KERN_DEBUG "arp_find is called with dst==NULL\n"); + kfree_skb(skb); + return 1; + } + + paddr = ((struct rtable*)skb->dst)->rt_gateway; + + if (arp_set_predefined(inet_addr_type(paddr), haddr, paddr, dev)) + return 0; + + start_bh_atomic(); + n = __neigh_lookup(&arp_tbl, &paddr, dev, 1); + + if (n) { + n->used = jiffies; + if (n->nud_state&NUD_VALID || neigh_event_send(n, skb) == 0) { + memcpy(haddr, n->ha, dev->addr_len); + neigh_release(n); + end_bh_atomic(); + return 0; + } + neigh_release(n); + } else + kfree_skb(skb); + end_bh_atomic(); + return 1; +} + +/* END OF OBSOLETE FUNCTIONS */ + +/* + * Note: requires bh_atomic locking. + */ +int arp_bind_neighbour(struct dst_entry *dst) +{ + struct device *dev = dst->dev; + + if (dev == NULL) + return 0; + if (dst->neighbour == NULL) { + u32 nexthop = ((struct rtable*)dst)->rt_gateway; + if (dev->flags&(IFF_LOOPBACK|IFF_POINTOPOINT)) + nexthop = 0; + dst->neighbour = __neigh_lookup(&arp_tbl, &nexthop, dev, 1); + } + return (dst->neighbour != NULL); +} + +/* + * Interface to link layer: send routine and receive handler. + */ + +/* + * Create and send an arp packet. If (dest_hw == NULL), we create a broadcast + * message. + */ + +void arp_send(int type, int ptype, u32 dest_ip, + struct device *dev, u32 src_ip, + unsigned char *dest_hw, unsigned char *src_hw, + unsigned char *target_hw) +{ + struct sk_buff *skb; + struct arphdr *arp; + unsigned char *arp_ptr; + + /* + * No arp on this interface. + */ + + if (dev->flags&IFF_NOARP) + return; + + /* + * Allocate a buffer + */ + + skb = alloc_skb(sizeof(struct arphdr)+ 2*(dev->addr_len+4) + + dev->hard_header_len + 15, GFP_ATOMIC); + if (skb == NULL) + return; + + skb_reserve(skb, (dev->hard_header_len+15)&~15); + skb->nh.raw = skb->data; + arp = (struct arphdr *) skb_put(skb,sizeof(struct arphdr) + 2*(dev->addr_len+4)); + skb->dev = dev; + skb->protocol = __constant_htons (ETH_P_ARP); + if (src_hw == NULL) + src_hw = dev->dev_addr; + if (dest_hw == NULL) + dest_hw = dev->broadcast; + + /* + * Fill the device header for the ARP frame + */ + dev->hard_header(skb,dev,ptype,dest_hw,src_hw,skb->len); + + /* + * Fill out the arp protocol part. + * + * The arp hardware type should match the device type, except for FDDI, + * which (according to RFC 1390) should always equal 1 (Ethernet). + */ + /* + * Exceptions everywhere. AX.25 uses the AX.25 PID value not the + * DIX code for the protocol. Make these device structure fields. + */ + switch (dev->type) { + default: + arp->ar_hrd = htons(dev->type); + arp->ar_pro = __constant_htons(ETH_P_IP); + break; + +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) + case ARPHRD_AX25: + arp->ar_hrd = __constant_htons(ARPHRD_AX25); + arp->ar_pro = __constant_htons(AX25_P_IP); + break; + +#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) + case ARPHRD_NETROM: + arp->ar_hrd = __constant_htons(ARPHRD_NETROM); + arp->ar_pro = __constant_htons(AX25_P_IP); + break; +#endif +#endif + +#ifdef CONFIG_FDDI + case ARPHRD_FDDI: + arp->ar_hrd = __constant_htons(ARPHRD_ETHER); + arp->ar_pro = __constant_htons(ETH_P_IP); + break; +#endif + } + + arp->ar_hln = dev->addr_len; + arp->ar_pln = 4; + arp->ar_op = htons(type); + + arp_ptr=(unsigned char *)(arp+1); + + memcpy(arp_ptr, src_hw, dev->addr_len); + arp_ptr+=dev->addr_len; + memcpy(arp_ptr, &src_ip,4); + arp_ptr+=4; + if (target_hw != NULL) + memcpy(arp_ptr, target_hw, dev->addr_len); + else + memset(arp_ptr, 0, dev->addr_len); + arp_ptr+=dev->addr_len; + memcpy(arp_ptr, &dest_ip, 4); + skb->dev = dev; + + dev_queue_xmit(skb); +} + +static void parp_redo(struct sk_buff *skb) +{ + arp_rcv(skb, skb->dev, NULL); +} + +/* + * Receive an arp request by the device layer. + */ + +int arp_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt) +{ + struct arphdr *arp = skb->nh.arph; + unsigned char *arp_ptr= (unsigned char *)(arp+1); + struct rtable *rt; + unsigned char *sha, *tha; + u32 sip, tip; + u16 dev_type = dev->type; + int addr_type; + struct in_device *in_dev = dev->ip_ptr; + struct neighbour *n; + +/* + * The hardware length of the packet should match the hardware length + * of the device. Similarly, the hardware types should match. The + * device should be ARP-able. Also, if pln is not 4, then the lookup + * is not from an IP number. We can't currently handle this, so toss + * it. + */ + if (in_dev == NULL || + arp->ar_hln != dev->addr_len || + dev->flags & IFF_NOARP || + skb->pkt_type == PACKET_OTHERHOST || + skb->pkt_type == PACKET_LOOPBACK || + arp->ar_pln != 4) + goto out; + + switch (dev_type) { + default: + if (arp->ar_pro != __constant_htons(ETH_P_IP)) + goto out; + if (htons(dev_type) != arp->ar_hrd) + goto out; + break; +#ifdef CONFIG_NET_ETHERNET + case ARPHRD_ETHER: + /* + * ETHERNET devices will accept ARP hardware types of either + * 1 (Ethernet) or 6 (IEEE 802.2). + */ + if (arp->ar_hrd != __constant_htons(ARPHRD_ETHER) && + arp->ar_hrd != __constant_htons(ARPHRD_IEEE802)) + goto out; + if (arp->ar_pro != __constant_htons(ETH_P_IP)) + goto out; + break; +#endif +#ifdef CONFIG_FDDI + case ARPHRD_FDDI: + /* + * According to RFC 1390, FDDI devices should accept ARP hardware types + * of 1 (Ethernet). However, to be more robust, we'll accept hardware + * types of either 1 (Ethernet) or 6 (IEEE 802.2). + */ + if (arp->ar_hrd != __constant_htons(ARPHRD_ETHER) && + arp->ar_hrd != __constant_htons(ARPHRD_IEEE802)) + goto out; + if (arp->ar_pro != __constant_htons(ETH_P_IP)) + goto out; + break; +#endif +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) + case ARPHRD_AX25: + if (arp->ar_pro != __constant_htons(AX25_P_IP)) + goto out; + if (arp->ar_hrd != __constant_htons(ARPHRD_AX25)) + goto out; + break; +#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE) + case ARPHRD_NETROM: + if (arp->ar_pro != __constant_htons(AX25_P_IP)) + goto out; + if (arp->ar_hrd != __constant_htons(ARPHRD_NETROM)) + goto out; + break; +#endif +#endif + } + + /* Undertsand only these message types */ + + if (arp->ar_op != __constant_htons(ARPOP_REPLY) && + arp->ar_op != __constant_htons(ARPOP_REQUEST)) + goto out; + +/* + * Extract fields + */ + sha=arp_ptr; + arp_ptr += dev->addr_len; + memcpy(&sip, arp_ptr, 4); + arp_ptr += 4; + tha=arp_ptr; + arp_ptr += dev->addr_len; + memcpy(&tip, arp_ptr, 4); +/* + * Check for bad requests for 127.x.x.x and requests for multicast + * addresses. If this is one such, delete it. + */ + if (LOOPBACK(tip) || MULTICAST(tip)) + goto out; + +/* + * Process entry. The idea here is we want to send a reply if it is a + * request for us or if it is a request for someone else that we hold + * a proxy for. We want to add an entry to our cache if it is a reply + * to us or if it is a request for our address. + * (The assumption for this last is that if someone is requesting our + * address, they are probably intending to talk to us, so it saves time + * if we cache their address. Their address is also probably not in + * our cache, since ours is not in their cache.) + * + * Putting this another way, we only care about replies if they are to + * us, in which case we add them to the cache. For requests, we care + * about those for us and those for our proxies. We reply to both, + * and in the case of requests for us we add the requester to the arp + * cache. + */ + + /* Special case: IPv4 duplicate address detection packet (RFC2131) */ + if (sip == 0) { + if (arp->ar_op == __constant_htons(ARPOP_REQUEST) && + inet_addr_type(tip) == RTN_LOCAL) + arp_send(ARPOP_REPLY,ETH_P_ARP,tip,dev,tip,sha,dev->dev_addr,dev->dev_addr); + goto out; + } + + if (arp->ar_op == __constant_htons(ARPOP_REQUEST) && + ip_route_input(skb, tip, sip, 0, dev) == 0) { + + rt = (struct rtable*)skb->dst; + addr_type = rt->rt_type; + + if (addr_type == RTN_LOCAL) { + n = neigh_event_ns(&arp_tbl, sha, &sip, dev); + if (n) { + arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); + neigh_release(n); + } + goto out; + } else if (IN_DEV_FORWARD(in_dev)) { + if ((rt->rt_flags&RTCF_DNAT) || + (addr_type == RTN_UNICAST && rt->u.dst.dev != dev && + (IN_DEV_PROXY_ARP(in_dev) || pneigh_lookup(&arp_tbl, &tip, dev, 0)))) { + n = neigh_event_ns(&arp_tbl, sha, &sip, dev); + neigh_release(n); + + if (skb->stamp.tv_sec == 0 || + skb->pkt_type == PACKET_HOST || + in_dev->arp_parms->proxy_delay == 0) { + arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr,sha); + } else { + pneigh_enqueue(&arp_tbl, in_dev->arp_parms, skb); + return 0; + } + goto out; + } + } + } + + /* Update our ARP tables */ + + n = __neigh_lookup(&arp_tbl, &sip, dev, 0); + +#ifdef CONFIG_IP_ACCEPT_UNSOLICITED_ARP + /* Unsolicited ARP is not accepted by default. + It is possible, that this option should be enabled for some + devices (strip is candidate) + */ + if (n == NULL && + arp->ar_op == __constant_htons(ARPOP_REPLY) && + inet_addr_type(sip) == RTN_UNICAST) + n = __neigh_lookup(&arp_tbl, &sip, dev, -1); +#endif + + if (n) { + int state = NUD_REACHABLE; + int override = 0; + + /* If several different ARP replies follows back-to-back, + use the FIRST one. It is possible, if several proxy + agents are active. Taking the first reply prevents + arp trashing and chooses the fastest router. + */ + if (jiffies - n->updated >= n->parms->locktime) + override = 1; + + /* Broadcast replies and request packets + do not assert neighbour reachability. + */ + if (arp->ar_op != __constant_htons(ARPOP_REPLY) || + skb->pkt_type != PACKET_HOST) + state = NUD_STALE; + neigh_update(n, sha, state, override, 1); + neigh_release(n); + } + +out: + kfree_skb(skb); + return 0; +} + + + +/* + * User level interface (ioctl, /proc) + */ + +/* + * Set (create) an ARP cache entry. + */ + +int arp_req_set(struct arpreq *r, struct device * dev) +{ + u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; + struct neighbour *neigh; + int err; + + if (r->arp_flags&ATF_PUBL) { + u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; + if (mask && mask != 0xFFFFFFFF) + return -EINVAL; + if (!dev && (r->arp_flags & ATF_COM)) { + dev = dev_getbyhwaddr(r->arp_ha.sa_family, r->arp_ha.sa_data); + if (!dev) + return -ENODEV; + } + if (mask) { + if (pneigh_lookup(&arp_tbl, &ip, dev, 1) == NULL) + return -ENOBUFS; + return 0; + } + if (dev == NULL) { + ipv4_devconf.proxy_arp = 1; + return 0; + } + if (dev->ip_ptr) { + ((struct in_device*)dev->ip_ptr)->cnf.proxy_arp = 1; + return 0; + } + return -ENXIO; + } + + if (r->arp_flags & ATF_PERM) + r->arp_flags |= ATF_COM; + if (dev == NULL) { + struct rtable * rt; + if ((err = ip_route_output(&rt, ip, 0, RTO_ONLINK, 0)) != 0) + return err; + dev = rt->u.dst.dev; + ip_rt_put(rt); + if (!dev) + return -EINVAL; + } + if (r->arp_ha.sa_family != dev->type) + return -EINVAL; + + err = -ENOBUFS; + start_bh_atomic(); + neigh = __neigh_lookup(&arp_tbl, &ip, dev, 1); + if (neigh) { + unsigned state = NUD_STALE; + if (r->arp_flags & ATF_PERM) + state = NUD_PERMANENT; + err = neigh_update(neigh, (r->arp_flags&ATF_COM) ? + r->arp_ha.sa_data : NULL, state, 1, 0); + neigh_release(neigh); + } + end_bh_atomic(); + return err; +} + +static unsigned arp_state_to_flags(struct neighbour *neigh) +{ + unsigned flags = 0; + if (neigh->nud_state&NUD_PERMANENT) + flags = ATF_PERM|ATF_COM; + else if (neigh->nud_state&NUD_VALID) + flags = ATF_COM; + return flags; +} + +/* + * Get an ARP cache entry. + */ + +static int arp_req_get(struct arpreq *r, struct device *dev) +{ + u32 ip = ((struct sockaddr_in *) &r->arp_pa)->sin_addr.s_addr; + struct neighbour *neigh; + int err = -ENXIO; + + start_bh_atomic(); + neigh = __neigh_lookup(&arp_tbl, &ip, dev, 0); + if (neigh) { + memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); + r->arp_ha.sa_family = dev->type; + strncpy(r->arp_dev, dev->name, sizeof(r->arp_dev)); + r->arp_flags = arp_state_to_flags(neigh); + neigh_release(neigh); + err = 0; + } + end_bh_atomic(); + return err; +} + +int arp_req_delete(struct arpreq *r, struct device * dev) +{ + int err; + u32 ip = ((struct sockaddr_in *)&r->arp_pa)->sin_addr.s_addr; + struct neighbour *neigh; + + if (r->arp_flags & ATF_PUBL) { + u32 mask = ((struct sockaddr_in *) &r->arp_netmask)->sin_addr.s_addr; + if (mask == 0xFFFFFFFF) + return pneigh_delete(&arp_tbl, &ip, dev); + if (mask == 0) { + if (dev == NULL) { + ipv4_devconf.proxy_arp = 0; + return 0; + } + if (dev->ip_ptr) { + ((struct in_device*)dev->ip_ptr)->cnf.proxy_arp = 0; + return 0; + } + return -ENXIO; + } + return -EINVAL; + } + + if (dev == NULL) { + struct rtable * rt; + if ((err = ip_route_output(&rt, ip, 0, RTO_ONLINK, 0)) != 0) + return err; + dev = rt->u.dst.dev; + ip_rt_put(rt); + if (!dev) + return -EINVAL; + } + err = -ENXIO; + start_bh_atomic(); + neigh = __neigh_lookup(&arp_tbl, &ip, dev, 0); + if (neigh) { + if (neigh->nud_state&~NUD_NOARP) + err = neigh_update(neigh, NULL, NUD_FAILED, 1, 0); + neigh_release(neigh); + } + end_bh_atomic(); + return err; +} + +/* + * Handle an ARP layer I/O control request. + */ + +int arp_ioctl(unsigned int cmd, void *arg) +{ + int err; + struct arpreq r; + struct device * dev = NULL; + + switch(cmd) { + case SIOCDARP: + case SIOCSARP: + if (!capable(CAP_NET_ADMIN)) + return -EPERM; + case SIOCGARP: + err = copy_from_user(&r, arg, sizeof(struct arpreq)); + if (err) + return -EFAULT; + break; + default: + return -EINVAL; + } + + if (r.arp_pa.sa_family != AF_INET) + return -EPFNOSUPPORT; + + if (!(r.arp_flags & ATF_PUBL) && + (r.arp_flags & (ATF_NETMASK|ATF_DONTPUB))) + return -EINVAL; + if (!(r.arp_flags & ATF_NETMASK)) + ((struct sockaddr_in *)&r.arp_netmask)->sin_addr.s_addr=__constant_htonl(0xFFFFFFFFUL); + + rtnl_lock(); + if (r.arp_dev[0]) { + err = -ENODEV; + if ((dev = dev_get(r.arp_dev)) == NULL) + goto out; + + /* Mmmm... It is wrong... ARPHRD_NETROM==0 */ + if (!r.arp_ha.sa_family) + r.arp_ha.sa_family = dev->type; + err = -EINVAL; + if ((r.arp_flags & ATF_COM) && r.arp_ha.sa_family != dev->type) + goto out; + } else if (cmd == SIOCGARP) { + err = -ENODEV; + goto out; + } + + switch(cmd) { + case SIOCDARP: + err = arp_req_delete(&r, dev); + break; + case SIOCSARP: + err = arp_req_set(&r, dev); + break; + case SIOCGARP: + err = arp_req_get(&r, dev); + if (!err && copy_to_user(arg, &r, sizeof(r))) + err = -EFAULT; + break; + } +out: + rtnl_unlock(); + return err; +} + +/* + * Write the contents of the ARP cache to a PROCfs file. + */ +#ifdef CONFIG_PROC_FS + +#define HBUFFERLEN 30 + +int arp_get_info(char *buffer, char **start, off_t offset, int length, int dummy) +{ + int len=0; + off_t pos=0; + int size; + char hbuffer[HBUFFERLEN]; + int i,j,k; + const char hexbuf[] = "0123456789ABCDEF"; + + size = sprintf(buffer,"IP address HW type Flags HW address Mask Device\n"); + + pos+=size; + len+=size; + + neigh_table_lock(&arp_tbl); + + for(i=0; i<=NEIGH_HASHMASK; i++) { + struct neighbour *n; + for (n=arp_tbl.hash_buckets[i]; n; n=n->next) { + struct device *dev = n->dev; + int hatype = dev->type; + + /* Do not confuse users "arp -a" with magic entries */ + if (!(n->nud_state&~NUD_NOARP)) + continue; + + /* I'd get great pleasure deleting + this ugly code. Let's output it in hexadecimal format. + "arp" utility will eventually repaired --ANK + */ +#if 1 /* UGLY CODE */ +/* + * Convert hardware address to XX:XX:XX:XX ... form. + */ +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) + if (hatype == ARPHRD_AX25 || hatype == ARPHRD_NETROM) + strcpy(hbuffer,ax2asc((ax25_address *)n->ha)); + else { +#endif + for (k=0,j=0;kaddr_len;j++) { + hbuffer[k++]=hexbuf[(n->ha[j]>>4)&15 ]; + hbuffer[k++]=hexbuf[n->ha[j]&15 ]; + hbuffer[k++]=':'; + } + hbuffer[--k]=0; + +#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE) + } +#endif +#else + if ((neigh->nud_state&NUD_VALID) && dev->addr_len) { + int j; + for (j=0; j < dev->addr_len; j++) + sprintf(hbuffer+2*j, "%02x", neigh->ha[j]); + } else + sprintf(hbuffer, "0"); +#endif + + size = sprintf(buffer+len, + "%-17s0x%-10x0x%-10x%s", + in_ntoa(*(u32*)n->primary_key), + hatype, + arp_state_to_flags(n), + hbuffer); + size += sprintf(buffer+len+size, + " %-17s %s\n", + "*", dev->name); + + len += size; + pos += size; + + if (pos <= offset) + len=0; + if (pos >= offset+length) + goto done; + } + } + + for (i=0; i<=PNEIGH_HASHMASK; i++) { + struct pneigh_entry *n; + for (n=arp_tbl.phash_buckets[i]; n; n=n->next) { + struct device *dev = n->dev; + int hatype = dev ? dev->type : 0; + + size = sprintf(buffer+len, + "%-17s0x%-10x0x%-10x%s", + in_ntoa(*(u32*)n->key), + hatype, + ATF_PUBL|ATF_PERM, + "00:00:00:00:00:00"); + size += sprintf(buffer+len+size, + " %-17s %s\n", + "*", dev ? dev->name : "*"); + + len += size; + pos += size; + + if (pos <= offset) + len=0; + if (pos >= offset+length) + goto done; + } + } + +done: + neigh_table_unlock(&arp_tbl); + + *start = buffer+len-(pos-offset); /* Start of wanted data */ + len = pos-offset; /* Start slop */ + if (len>length) + len = length; /* Ending slop */ + if (len<0) + len = 0; + return len; +} +#endif + +/* Note, that it is not on notifier chain. + It is necessary, that this routine was called after route cache will be + flushed. + */ +void arp_ifdown(struct device *dev) +{ + neigh_ifdown(&arp_tbl, dev); +} + + +/* + * Called once on startup. + */ + +static struct packet_type arp_packet_type = +{ + __constant_htons(ETH_P_ARP), + NULL, /* All devices */ + arp_rcv, + NULL, + NULL +}; + +#ifdef CONFIG_PROC_FS +static struct proc_dir_entry proc_net_arp = { + PROC_NET_ARP, 3, "arp", + S_IFREG | S_IRUGO, 1, 0, 0, + 0, &proc_net_inode_operations, + arp_get_info +}; +#endif + +__initfunc(void arp_init (void)) +{ + neigh_table_init(&arp_tbl); + + dev_add_pack(&arp_packet_type); + +#ifdef CONFIG_PROC_FS + proc_net_register(&proc_net_arp); +#endif +#ifdef CONFIG_SYSCTL + neigh_sysctl_register(NULL, &arp_tbl.parms, NET_IPV4, NET_IPV4_NEIGH, "ipv4"); +#endif +} + + +#ifdef CONFIG_AX25_MODULE + +/* + * ax25 -> ASCII conversion + */ +char *ax2asc(ax25_address *a) +{ + static char buf[11]; + char c, *s; + int n; + + for (n = 0, s = buf; n < 6; n++) { + c = (a->ax25_call[n] >> 1) & 0x7F; + + if (c != ' ') *s++ = c; + } + + *s++ = '-'; + + if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) { + *s++ = '1'; + n -= 10; + } + + *s++ = n + '0'; + *s++ = '\0'; + + if (*buf == '\0' || *buf == '-') + return "*"; + + return buf; + +} + +#endif -- cgit v1.2.3