diff options
Diffstat (limited to 'pfinet/linux-inet/arp.c')
| -rw-r--r-- | pfinet/linux-inet/arp.c | 1295 |
1 files changed, 0 insertions, 1295 deletions
diff --git a/pfinet/linux-inet/arp.c b/pfinet/linux-inet/arp.c deleted file mode 100644 index 5e00caf7..00000000 --- a/pfinet/linux-inet/arp.c +++ /dev/null @@ -1,1295 +0,0 @@ -/* linux/net/inet/arp.c - * - * 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). - * - * FIXME: - * Experiment with better retransmit timers - * Clean up the timer deletions - * If you create a proxy entry set your interface address to the address - * and then delete it, proxies may get out of sync with reality - check this - * - * 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! - */ - -#include <linux/types.h> -#include <linux/string.h> -#include <linux/kernel.h> -#include <linux/sched.h> -#include <linux/config.h> -#include <linux/socket.h> -#include <linux/sockios.h> -#include <linux/errno.h> -#include <linux/if_arp.h> -#include <linux/in.h> -#include <linux/mm.h> -#include <asm/system.h> -#include <asm/segment.h> -#include <stdarg.h> -#include <linux/inet.h> -#include <linux/netdevice.h> -#include <linux/etherdevice.h> -#include "ip.h" -#include "route.h" -#include "protocol.h" -#include "tcp.h" -#include <linux/skbuff.h> -#include "sock.h" -#include "arp.h" -#ifdef CONFIG_AX25 -#include "ax25.h" -#endif - - -/* - * This structure defines the ARP mapping cache. As long as we make changes - * in this structure, we keep interrupts of. But normally we can copy the - * hardware address and the device pointer in a local variable and then make - * any "long calls" to send a packet out. - */ - -struct arp_table -{ - struct arp_table *next; /* Linked entry list */ - unsigned long last_used; /* For expiry */ - unsigned int flags; /* Control status */ - unsigned long ip; /* ip address of entry */ - unsigned long mask; /* netmask - used for generalised proxy arps (tridge) */ - unsigned char ha[MAX_ADDR_LEN]; /* Hardware address */ - unsigned char hlen; /* Length of hardware address */ - unsigned short htype; /* Type of hardware in use */ - struct device *dev; /* Device the entry is tied to */ - - /* - * The following entries are only used for unresolved hw addresses. - */ - - struct timer_list timer; /* expire timer */ - int retries; /* remaining retries */ - struct sk_buff_head skb; /* list of queued packets */ -}; - - -/* - * Configurable Parameters (don't touch unless you know what you are doing - */ - -/* - * If an arp request is send, ARP_RES_TIME is the timeout value until the - * next request is send. - */ - -#define ARP_RES_TIME (250*(HZ/10)) - -/* - * The number of times an arp request is send, until the host is - * considered unreachable. - */ - -#define ARP_MAX_TRIES 3 - -/* - * After that time, an unused entry is deleted from the arp table. - */ - -#define ARP_TIMEOUT (600*HZ) - -/* - * How often is the function 'arp_check_retries' called. - * An entry is invalidated in the time between ARP_TIMEOUT and - * (ARP_TIMEOUT+ARP_CHECK_INTERVAL). - */ - -#define ARP_CHECK_INTERVAL (60 * HZ) - -enum proxy { - PROXY_EXACT=0, - PROXY_ANY, - PROXY_NONE, -}; - -/* Forward declarations. */ -static void arp_check_expire (unsigned long); -static struct arp_table *arp_lookup(unsigned long paddr, enum proxy proxy); - - -static struct timer_list arp_timer = - { NULL, NULL, ARP_CHECK_INTERVAL, 0L, &arp_check_expire }; - -/* - * The default arp netmask is just 255.255.255.255 which means it's - * a single machine entry. Only proxy entries can have other netmasks - * -*/ - -#define DEF_ARP_NETMASK (~0) - - -/* - * The size of the hash table. Must be a power of two. - * Maybe we should remove hashing in the future for arp and concentrate - * on Patrick Schaaf's Host-Cache-Lookup... - */ - - -#define ARP_TABLE_SIZE 16 - -/* The ugly +1 here is to cater for proxy entries. They are put in their - own list for efficiency of lookup. If you don't want to find a proxy - entry then don't look in the last entry, otherwise do -*/ - -#define FULL_ARP_TABLE_SIZE (ARP_TABLE_SIZE+1) - -struct arp_table *arp_tables[FULL_ARP_TABLE_SIZE] = -{ - NULL, -}; - - -/* - * The last bits in the IP address are used for the cache lookup. - * A special entry is used for proxy arp entries - */ - -#define HASH(paddr) (htonl(paddr) & (ARP_TABLE_SIZE - 1)) -#define PROXY_HASH ARP_TABLE_SIZE - -/* - * Check if there are too old entries and remove them. If the ATF_PERM - * flag is set, they are always left in the arp cache (permanent entry). - * Note: Only fully resolved entries, which don't have any packets in - * the queue, can be deleted, since ARP_TIMEOUT is much greater than - * ARP_MAX_TRIES*ARP_RES_TIME. - */ - -static void arp_check_expire(unsigned long dummy) -{ - int i; - unsigned long now = jiffies; - unsigned long flags; - save_flags(flags); - cli(); - - for (i = 0; i < FULL_ARP_TABLE_SIZE; i++) - { - struct arp_table *entry; - struct arp_table **pentry = &arp_tables[i]; - - while ((entry = *pentry) != NULL) - { - if ((now - entry->last_used) > ARP_TIMEOUT - && !(entry->flags & ATF_PERM)) - { - *pentry = entry->next; /* remove from list */ - del_timer(&entry->timer); /* Paranoia */ - kfree_s(entry, sizeof(struct arp_table)); - } - else - pentry = &entry->next; /* go to next entry */ - } - } - restore_flags(flags); - - /* - * Set the timer again. - */ - - del_timer(&arp_timer); - arp_timer.expires = ARP_CHECK_INTERVAL; - add_timer(&arp_timer); -} - - -/* - * Release all linked skb's and the memory for this entry. - */ - -static void arp_release_entry(struct arp_table *entry) -{ - struct sk_buff *skb; - unsigned long flags; - - save_flags(flags); - cli(); - /* Release the list of `skb' pointers. */ - while ((skb = skb_dequeue(&entry->skb)) != NULL) - { - skb_device_lock(skb); - restore_flags(flags); - dev_kfree_skb(skb, FREE_WRITE); - } - restore_flags(flags); - del_timer(&entry->timer); - kfree_s(entry, sizeof(struct arp_table)); - return; -} - -/* - * Purge a device from the ARP queue - */ - -int arp_device_event(unsigned long event, void *ptr) -{ - struct device *dev=ptr; - int i; - unsigned long flags; - - if(event!=NETDEV_DOWN) - return NOTIFY_DONE; - /* - * This is a bit OTT - maybe we need some arp semaphores instead. - */ - - save_flags(flags); - cli(); - for (i = 0; i < FULL_ARP_TABLE_SIZE; i++) - { - struct arp_table *entry; - struct arp_table **pentry = &arp_tables[i]; - - while ((entry = *pentry) != NULL) - { - if(entry->dev==dev) - { - *pentry = entry->next; /* remove from list */ - del_timer(&entry->timer); /* Paranoia */ - kfree_s(entry, sizeof(struct arp_table)); - } - else - pentry = &entry->next; /* go to next entry */ - } - } - restore_flags(flags); - return NOTIFY_DONE; -} - - -/* - * Create and send an arp packet. If (dest_hw == NULL), we create a broadcast - * message. - */ - -void arp_send(int type, int ptype, unsigned long dest_ip, - struct device *dev, unsigned long src_ip, - unsigned char *dest_hw, unsigned char *src_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, GFP_ATOMIC); - if (skb == NULL) - { - printk("ARP: no memory to send an arp packet\n"); - return; - } - skb->len = sizeof(struct arphdr) + dev->hard_header_len + 2*(dev->addr_len+4); - skb->arp = 1; - skb->dev = dev; - skb->free = 1; - - /* - * Fill the device header for the ARP frame - */ - - dev->hard_header(skb->data,dev,ptype,dest_hw?dest_hw:dev->broadcast,src_hw?src_hw:NULL,skb->len,skb); - - /* Fill out the arp protocol part. */ - arp = (struct arphdr *) (skb->data + dev->hard_header_len); - arp->ar_hrd = htons(dev->type); -#ifdef CONFIG_AX25 - arp->ar_pro = (dev->type != ARPHRD_AX25)? htons(ETH_P_IP) : htons(AX25_P_IP); -#else - arp->ar_pro = htons(ETH_P_IP); -#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 (dest_hw != NULL) - memcpy(arp_ptr, dest_hw, dev->addr_len); - else - memset(arp_ptr, 0, dev->addr_len); - arp_ptr+=dev->addr_len; - memcpy(arp_ptr, &dest_ip, 4); - - dev_queue_xmit(skb, dev, 0); -} - - -/* - * This function is called, if an entry is not resolved in ARP_RES_TIME. - * Either resend a request, or give it up and free the entry. - */ - -static void arp_expire_request (unsigned long arg) -{ - struct arp_table *entry = (struct arp_table *) arg; - struct arp_table **pentry; - unsigned long hash; - unsigned long flags; - - save_flags(flags); - cli(); - - /* - * Since all timeouts are handled with interrupts enabled, there is a - * small chance, that this entry has just been resolved by an incoming - * packet. This is the only race condition, but it is handled... - */ - - if (entry->flags & ATF_COM) - { - restore_flags(flags); - return; - } - - if (--entry->retries > 0) - { - unsigned long ip = entry->ip; - struct device *dev = entry->dev; - - /* Set new timer. */ - del_timer(&entry->timer); - entry->timer.expires = ARP_RES_TIME; - add_timer(&entry->timer); - restore_flags(flags); - arp_send(ARPOP_REQUEST, ETH_P_ARP, ip, dev, dev->pa_addr, - NULL, dev->dev_addr); - return; - } - - /* - * Arp request timed out. Delete entry and all waiting packets. - * If we give each entry a pointer to itself, we don't have to - * loop through everything again. Maybe hash is good enough, but - * I will look at it later. - */ - - hash = HASH(entry->ip); - - /* proxy entries shouldn't really time out so this is really - only here for completeness - */ - if (entry->flags & ATF_PUBL) - pentry = &arp_tables[PROXY_HASH]; - else - pentry = &arp_tables[hash]; - while (*pentry != NULL) - { - if (*pentry == entry) - { - *pentry = entry->next; /* delete from linked list */ - del_timer(&entry->timer); - restore_flags(flags); - arp_release_entry(entry); - return; - } - pentry = &(*pentry)->next; - } - restore_flags(flags); - printk("Possible ARP queue corruption.\n"); - /* - * We should never arrive here. - */ -} - - -/* - * This will try to retransmit everything on the queue. - */ - -static void arp_send_q(struct arp_table *entry, unsigned char *hw_dest) -{ - struct sk_buff *skb; - - unsigned long flags; - - /* - * Empty the entire queue, building its data up ready to send - */ - - if(!(entry->flags&ATF_COM)) - { - printk("arp_send_q: incomplete entry for %s\n", - in_ntoa(entry->ip)); - return; - } - - save_flags(flags); - - cli(); - while((skb = skb_dequeue(&entry->skb)) != NULL) - { - IS_SKB(skb); - skb_device_lock(skb); - restore_flags(flags); - if(!skb->dev->rebuild_header(skb->data,skb->dev,skb->raddr,skb)) - { - skb->arp = 1; - if(skb->sk==NULL) - dev_queue_xmit(skb, skb->dev, 0); - else - dev_queue_xmit(skb,skb->dev,skb->sk->priority); - } - else - { - /* This routine is only ever called when 'entry' is - complete. Thus this can't fail. */ - printk("arp_send_q: The impossible occurred. Please notify Alan.\n"); - printk("arp_send_q: active entity %s\n",in_ntoa(entry->ip)); - printk("arp_send_q: failed to find %s\n",in_ntoa(skb->raddr)); - } - } - restore_flags(flags); -} - - -/* - * Delete an ARP mapping entry in the cache. - */ - -void arp_destroy(unsigned long ip_addr, int force) -{ - int checked_proxies = 0; - struct arp_table *entry; - struct arp_table **pentry; - unsigned long hash = HASH(ip_addr); - -ugly: - cli(); - pentry = &arp_tables[hash]; - if (! *pentry) /* also check proxy entries */ - pentry = &arp_tables[PROXY_HASH]; - - while ((entry = *pentry) != NULL) - { - if (entry->ip == ip_addr) - { - if ((entry->flags & ATF_PERM) && !force) - return; - *pentry = entry->next; - del_timer(&entry->timer); - sti(); - arp_release_entry(entry); - /* this would have to be cleaned up */ - goto ugly; - /* perhaps like this ? - cli(); - entry = *pentry; - */ - } - pentry = &entry->next; - if (!checked_proxies && ! *pentry) - { /* ugly. we have to make sure we check proxy - entries as well */ - checked_proxies = 1; - pentry = &arp_tables[PROXY_HASH]; - } - } - sti(); -} - - -/* - * Receive an arp request by the device layer. Maybe I rewrite it, to - * use the incoming packet for the reply. The time for the current - * "overhead" isn't that high... - */ - -int arp_rcv(struct sk_buff *skb, struct device *dev, struct packet_type *pt) -{ -/* - * We shouldn't use this type conversion. Check later. - */ - - struct arphdr *arp = (struct arphdr *)skb->h.raw; - unsigned char *arp_ptr= (unsigned char *)(arp+1); - struct arp_table *entry; - struct arp_table *proxy_entry; - int addr_hint,hlen,htype; - unsigned long hash; - unsigned char ha[MAX_ADDR_LEN]; /* So we can enable ints again. */ - long sip,tip; - unsigned char *sha,*tha; - -/* - * 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 (arp->ar_hln != dev->addr_len || - dev->type != ntohs(arp->ar_hrd) || - dev->flags & IFF_NOARP || - arp->ar_pln != 4) - { - kfree_skb(skb, FREE_READ); - return 0; - } - -/* - * Another test. - * The logic here is that the protocol being looked up by arp should - * match the protocol the device speaks. If it doesn't, there is a - * problem, so toss the packet. - */ - switch(dev->type) - { -#ifdef CONFIG_AX25 - case ARPHRD_AX25: - if(arp->ar_pro != htons(AX25_P_IP)) - { - kfree_skb(skb, FREE_READ); - return 0; - } - break; -#endif - case ARPHRD_ETHER: - case ARPHRD_ARCNET: - if(arp->ar_pro != htons(ETH_P_IP)) - { - kfree_skb(skb, FREE_READ); - return 0; - } - break; - - default: - printk("ARP: dev->type mangled!\n"); - kfree_skb(skb, FREE_READ); - return 0; - } - -/* - * Extract fields - */ - - hlen = dev->addr_len; - htype = dev->type; - - sha=arp_ptr; - arp_ptr+=hlen; - memcpy(&sip,arp_ptr,4); - arp_ptr+=4; - tha=arp_ptr; - arp_ptr+=hlen; - memcpy(&tip,arp_ptr,4); - -/* - * Check for bad requests for 127.0.0.1. If this is one such, delete it. - */ - if(tip == INADDR_LOOPBACK) - { - kfree_skb(skb, FREE_READ); - return 0; - } - -/* - * 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. - */ - - addr_hint = ip_chk_addr(tip); - - if(arp->ar_op == htons(ARPOP_REPLY)) - { - if(addr_hint!=IS_MYADDR) - { -/* - * Replies to other machines get tossed. - */ - kfree_skb(skb, FREE_READ); - return 0; - } -/* - * Fall through to code below that adds sender to cache. - */ - } - else - { -/* - * It is now an arp request - */ -/* - * Only reply for the real device address or when it's in our proxy tables - */ - if(tip!=dev->pa_addr) - { -/* - * To get in here, it is a request for someone else. We need to - * check if that someone else is one of our proxies. If it isn't, - * we can toss it. - */ - cli(); - for(proxy_entry=arp_tables[PROXY_HASH]; - proxy_entry; - proxy_entry = proxy_entry->next) - { - /* we will respond to a proxy arp request - if the masked arp table ip matches the masked - tip. This allows a single proxy arp table - entry to be used on a gateway machine to handle - all requests for a whole network, rather than - having to use a huge number of proxy arp entries - and having to keep them uptodate. - */ - if (proxy_entry->dev != dev && proxy_entry->htype == htype && - !((proxy_entry->ip^tip)&proxy_entry->mask)) - break; - - } - if (proxy_entry) - { - memcpy(ha, proxy_entry->ha, hlen); - sti(); - arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,ha); - kfree_skb(skb, FREE_READ); - return 0; - } - else - { - sti(); - kfree_skb(skb, FREE_READ); - return 0; - } - } - else - { -/* - * To get here, it must be an arp request for us. We need to reply. - */ - arp_send(ARPOP_REPLY,ETH_P_ARP,sip,dev,tip,sha,dev->dev_addr); - } - } - - -/* - * Now all replies are handled. Next, anything that falls through to here - * needs to be added to the arp cache, or have its entry updated if it is - * there. - */ - - hash = HASH(sip); - cli(); - for(entry=arp_tables[hash];entry;entry=entry->next) - if(entry->ip==sip && entry->htype==htype) - break; - - if(entry) - { -/* - * Entry found; update it. - */ - memcpy(entry->ha, sha, hlen); - entry->hlen = hlen; - entry->last_used = jiffies; - if (!(entry->flags & ATF_COM)) - { -/* - * This entry was incomplete. Delete the retransmit timer - * and switch to complete status. - */ - del_timer(&entry->timer); - entry->flags |= ATF_COM; - sti(); -/* - * Send out waiting packets. We might have problems, if someone is - * manually removing entries right now -- entry might become invalid - * underneath us. - */ - arp_send_q(entry, sha); - } - else - { - sti(); - } - } - else - { -/* - * No entry found. Need to add a new entry to the arp table. - */ - entry = (struct arp_table *)kmalloc(sizeof(struct arp_table),GFP_ATOMIC); - if(entry == NULL) - { - sti(); - printk("ARP: no memory for new arp entry\n"); - - kfree_skb(skb, FREE_READ); - return 0; - } - - entry->mask = DEF_ARP_NETMASK; - entry->ip = sip; - entry->hlen = hlen; - entry->htype = htype; - entry->flags = ATF_COM; - init_timer(&entry->timer); - memcpy(entry->ha, sha, hlen); - entry->last_used = jiffies; - entry->dev = skb->dev; - skb_queue_head_init(&entry->skb); - entry->next = arp_tables[hash]; - arp_tables[hash] = entry; - sti(); - } - -/* - * Replies have been sent, and entries have been added. All done. - */ - kfree_skb(skb, FREE_READ); - return 0; -} - - -/* - * Find an arp mapping in the cache. If not found, post a request. - */ - -int arp_find(unsigned char *haddr, unsigned long paddr, struct device *dev, - unsigned long saddr, struct sk_buff *skb) -{ - struct arp_table *entry; - unsigned long hash; -#ifdef CONFIG_IP_MULTICAST - unsigned long taddr; -#endif - - switch (ip_chk_addr(paddr)) - { - case IS_MYADDR: - printk("ARP: arp called for own IP address\n"); - memcpy(haddr, dev->dev_addr, dev->addr_len); - skb->arp = 1; - return 0; -#ifdef CONFIG_IP_MULTICAST - case IS_MULTICAST: - if(dev->type==ARPHRD_ETHER || dev->type==ARPHRD_IEEE802) - { - haddr[0]=0x01; - haddr[1]=0x00; - haddr[2]=0x5e; - taddr=ntohl(paddr); - haddr[5]=taddr&0xff; - taddr=taddr>>8; - haddr[4]=taddr&0xff; - taddr=taddr>>8; - haddr[3]=taddr&0x7f; - return 0; - } - /* - * If a device does not support multicast broadcast the stuff (eg AX.25 for now) - */ -#endif - - case IS_BROADCAST: - memcpy(haddr, dev->broadcast, dev->addr_len); - skb->arp = 1; - return 0; - } - - hash = HASH(paddr); - cli(); - - /* - * Find an entry - */ - entry = arp_lookup(paddr, PROXY_NONE); - - if (entry != NULL) /* It exists */ - { - if (!(entry->flags & ATF_COM)) - { - /* - * A request was already send, but no reply yet. Thus - * queue the packet with the previous attempt - */ - - if (skb != NULL) - { - skb_queue_tail(&entry->skb, skb); - skb_device_unlock(skb); - } - sti(); - return 1; - } - - /* - * Update the record - */ - - entry->last_used = jiffies; - memcpy(haddr, entry->ha, dev->addr_len); - if (skb) - skb->arp = 1; - sti(); - return 0; - } - - /* - * Create a new unresolved entry. - */ - - entry = (struct arp_table *) kmalloc(sizeof(struct arp_table), - GFP_ATOMIC); - if (entry != NULL) - { - entry->mask = DEF_ARP_NETMASK; - entry->ip = paddr; - entry->hlen = dev->addr_len; - entry->htype = dev->type; - entry->flags = 0; - memset(entry->ha, 0, dev->addr_len); - entry->dev = dev; - entry->last_used = jiffies; - init_timer(&entry->timer); - entry->timer.function = arp_expire_request; - entry->timer.data = (unsigned long)entry; - entry->timer.expires = ARP_RES_TIME; - entry->next = arp_tables[hash]; - arp_tables[hash] = entry; - add_timer(&entry->timer); - entry->retries = ARP_MAX_TRIES; - skb_queue_head_init(&entry->skb); - if (skb != NULL) - { - skb_queue_tail(&entry->skb, skb); - skb_device_unlock(skb); - } - } - else - { - if (skb != NULL && skb->free) - kfree_skb(skb, FREE_WRITE); - } - sti(); - - /* - * If we didn't find an entry, we will try to send an ARP packet. - */ - - arp_send(ARPOP_REQUEST, ETH_P_ARP, paddr, dev, saddr, NULL, - dev->dev_addr); - - return 1; -} - - -/* - * Write the contents of the ARP cache to a PROCfs file. - */ - -#define HBUFFERLEN 30 - -int arp_get_info(char *buffer, char **start, off_t offset, int length) -{ - int len=0; - off_t begin=0; - off_t pos=0; - int size; - struct arp_table *entry; - char hbuffer[HBUFFERLEN]; - int i,j,k; - const char hexbuf[] = "0123456789ABCDEF"; - - size = sprintf(buffer,"IP address HW type Flags HW address Mask\n"); - - pos+=size; - len+=size; - - cli(); - for(i=0; i<FULL_ARP_TABLE_SIZE; i++) - { - for(entry=arp_tables[i]; entry!=NULL; entry=entry->next) - { -/* - * Convert hardware address to XX:XX:XX:XX ... form. - */ -#ifdef CONFIG_AX25 - - if(entry->htype==ARPHRD_AX25) - strcpy(hbuffer,ax2asc((ax25_address *)entry->ha)); - else { -#endif - - for(k=0,j=0;k<HBUFFERLEN-3 && j<entry->hlen;j++) - { - hbuffer[k++]=hexbuf[ (entry->ha[j]>>4)&15 ]; - hbuffer[k++]=hexbuf[ entry->ha[j]&15 ]; - hbuffer[k++]=':'; - } - hbuffer[--k]=0; - -#ifdef CONFIG_AX25 - } -#endif - size = sprintf(buffer+len, - "%-17s0x%-10x0x%-10x%s", - in_ntoa(entry->ip), - (unsigned int)entry->htype, - entry->flags, - hbuffer); - size += sprintf(buffer+len+size, - " %-17s\n", - entry->mask==DEF_ARP_NETMASK? - "*":in_ntoa(entry->mask)); - - len+=size; - pos=begin+len; - - if(pos<offset) - { - len=0; - begin=pos; - } - if(pos>offset+length) - break; - } - } - sti(); - - *start=buffer+(offset-begin); /* Start of wanted data */ - len-=(offset-begin); /* Start slop */ - if(len>length) - len=length; /* Ending slop */ - return len; -} - - -/* - * This will find an entry in the ARP table by looking at the IP address. - * If proxy is PROXY_EXACT then only exact IP matches will be allowed - * for proxy entries, otherwise the netmask will be used - */ - -static struct arp_table *arp_lookup(unsigned long paddr, enum proxy proxy) -{ - struct arp_table *entry; - unsigned long hash = HASH(paddr); - - for (entry = arp_tables[hash]; entry != NULL; entry = entry->next) - if (entry->ip == paddr) break; - - /* it's possibly a proxy entry (with a netmask) */ - if (!entry && proxy != PROXY_NONE) - for (entry=arp_tables[PROXY_HASH]; entry != NULL; entry = entry->next) - if ((proxy==PROXY_EXACT) ? (entry->ip==paddr) - : !((entry->ip^paddr)&entry->mask)) - break; - - return entry; -} - - -/* - * Set (create) an ARP cache entry. - */ - -static int arp_req_set(struct arpreq *req) -{ - struct arpreq r; - struct arp_table *entry; - struct sockaddr_in *si; - int htype, hlen; - unsigned long ip; - struct rtable *rt; - - memcpy_fromfs(&r, req, sizeof(r)); - - /* We only understand about IP addresses... */ - if (r.arp_pa.sa_family != AF_INET) - return -EPFNOSUPPORT; - - /* - * Find out about the hardware type. - * We have to be compatible with BSD UNIX, so we have to - * assume that a "not set" value (i.e. 0) means Ethernet. - */ - - switch (r.arp_ha.sa_family) { - case ARPHRD_ETHER: - htype = ARPHRD_ETHER; - hlen = ETH_ALEN; - break; - - case ARPHRD_ARCNET: - htype = ARPHRD_ARCNET; - hlen = 1; /* length of arcnet addresses */ - break; - -#ifdef CONFIG_AX25 - case ARPHRD_AX25: - htype = ARPHRD_AX25; - hlen = 7; - break; -#endif - default: - return -EPFNOSUPPORT; - } - - si = (struct sockaddr_in *) &r.arp_pa; - ip = si->sin_addr.s_addr; - if (ip == 0) - { - printk("ARP: SETARP: requested PA is 0.0.0.0 !\n"); - return -EINVAL; - } - - /* - * Is it reachable directly ? - */ - - rt = ip_rt_route(ip, NULL, NULL); - if (rt == NULL) - return -ENETUNREACH; - - /* - * Is there an existing entry for this address? - */ - - cli(); - - /* - * Find the entry - */ - entry = arp_lookup(ip, PROXY_EXACT); - if (entry && (entry->flags & ATF_PUBL) != (r.arp_flags & ATF_PUBL)) - { - sti(); - arp_destroy(ip,1); - cli(); - entry = NULL; - } - - /* - * Do we need to create a new entry - */ - - if (entry == NULL) - { - unsigned long hash = HASH(ip); - if (r.arp_flags & ATF_PUBL) - hash = PROXY_HASH; - - entry = (struct arp_table *) kmalloc(sizeof(struct arp_table), - GFP_ATOMIC); - if (entry == NULL) - { - sti(); - return -ENOMEM; - } - entry->ip = ip; - entry->hlen = hlen; - entry->htype = htype; - init_timer(&entry->timer); - entry->next = arp_tables[hash]; - arp_tables[hash] = entry; - skb_queue_head_init(&entry->skb); - } - /* - * We now have a pointer to an ARP entry. Update it! - */ - - memcpy(&entry->ha, &r.arp_ha.sa_data, hlen); - entry->last_used = jiffies; - entry->flags = r.arp_flags | ATF_COM; - if ((entry->flags & ATF_PUBL) && (entry->flags & ATF_NETMASK)) - { - si = (struct sockaddr_in *) &r.arp_netmask; - entry->mask = si->sin_addr.s_addr; - } - else - entry->mask = DEF_ARP_NETMASK; - entry->dev = rt->rt_dev; - sti(); - - return 0; -} - - -/* - * Get an ARP cache entry. - */ - -static int arp_req_get(struct arpreq *req) -{ - struct arpreq r; - struct arp_table *entry; - struct sockaddr_in *si; - - /* - * We only understand about IP addresses... - */ - - memcpy_fromfs(&r, req, sizeof(r)); - - if (r.arp_pa.sa_family != AF_INET) - return -EPFNOSUPPORT; - - /* - * Is there an existing entry for this address? - */ - - si = (struct sockaddr_in *) &r.arp_pa; - cli(); - entry = arp_lookup(si->sin_addr.s_addr,PROXY_ANY); - - if (entry == NULL) - { - sti(); - return -ENXIO; - } - - /* - * We found it; copy into structure. - */ - - memcpy(r.arp_ha.sa_data, &entry->ha, entry->hlen); - r.arp_ha.sa_family = entry->htype; - r.arp_flags = entry->flags; - sti(); - - /* - * Copy the information back - */ - - memcpy_tofs(req, &r, sizeof(r)); - return 0; -} - - -#ifndef _HURD_ -/* - * Handle an ARP layer I/O control request. - */ - -int arp_ioctl(unsigned int cmd, void *arg) -{ - struct arpreq r; - struct sockaddr_in *si; - int err; - - switch(cmd) - { - case SIOCDARP: - if (!suser()) - return -EPERM; - err = verify_area(VERIFY_READ, arg, sizeof(struct arpreq)); - if(err) - return err; - memcpy_fromfs(&r, arg, sizeof(r)); - if (r.arp_pa.sa_family != AF_INET) - return -EPFNOSUPPORT; - si = (struct sockaddr_in *) &r.arp_pa; - arp_destroy(si->sin_addr.s_addr, 1); - return 0; - case SIOCGARP: - err = verify_area(VERIFY_WRITE, arg, sizeof(struct arpreq)); - if(err) - return err; - return arp_req_get((struct arpreq *)arg); - case SIOCSARP: - if (!suser()) - return -EPERM; - err = verify_area(VERIFY_READ, arg, sizeof(struct arpreq)); - if(err) - return err; - return arp_req_set((struct arpreq *)arg); - default: - return -EINVAL; - } - /*NOTREACHED*/ - return 0; -} -#endif - -/* - * Called once on startup. - */ - -static struct packet_type arp_packet_type = -{ - 0, /* Should be: __constant_htons(ETH_P_ARP) - but this _doesn't_ come out constant! */ - NULL, /* All devices */ - arp_rcv, - NULL, - NULL -}; - -static struct notifier_block arp_dev_notifier={ - arp_device_event, - NULL, - 0 -}; - -void arp_init (void) -{ - /* Register the packet type */ - arp_packet_type.type=htons(ETH_P_ARP); - dev_add_pack(&arp_packet_type); - /* Start with the regular checks for expired arp entries. */ - add_timer(&arp_timer); - /* Register for device down reports */ - register_netdevice_notifier(&arp_dev_notifier); -} - |