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/*
* NET3: Token ring device handling subroutines
*
* 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: 3 Feb 97 Paul Norton <pnorton@cts.com> Minor routing fixes.
* Added rif table to /proc/net/tr_rif and rif timeout to
* /proc/sys/net/token-ring/rif_timeout.
* 22 Jun 98 Paul Norton <p.norton@computer.org> Rearranged
* tr_header and tr_type_trans to handle passing IPX SNAP and
* 802.2 through the correct layers. Eliminated tr_reformat.
*
*/
#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <linux/trdevice.h>
#include <linux/skbuff.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/net.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <net/arp.h>
static void tr_source_route(struct sk_buff *skb, struct trh_hdr *trh, struct net_device *dev);
static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev);
static void rif_check_expire(unsigned long dummy);
#define TR_SR_DEBUG 0
typedef struct rif_cache_s *rif_cache;
/*
* Each RIF entry we learn is kept this way
*/
struct rif_cache_s {
unsigned char addr[TR_ALEN];
int iface;
__u16 rcf;
__u16 rseg[8];
rif_cache next;
unsigned long last_used;
unsigned char local_ring;
};
#define RIF_TABLE_SIZE 32
/*
* We hash the RIF cache 32 ways. We do after all have to look it
* up a lot.
*/
rif_cache rif_table[RIF_TABLE_SIZE]={ NULL, };
static spinlock_t rif_lock = SPIN_LOCK_UNLOCKED;
#define RIF_TIMEOUT 60*10*HZ
#define RIF_CHECK_INTERVAL 60*HZ
/*
* Garbage disposal timer.
*/
static struct timer_list rif_timer;
int sysctl_tr_rif_timeout = RIF_TIMEOUT;
/*
* Put the headers on a token ring packet. Token ring source routing
* makes this a little more exciting than on ethernet.
*/
int tr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type,
void *daddr, void *saddr, unsigned len)
{
struct trh_hdr *trh;
int hdr_len;
/*
* Add the 802.2 SNAP header if IP as the IPv4 code calls
* dev->hard_header directly.
*/
if (type == ETH_P_IP || type == ETH_P_ARP)
{
struct trllc *trllc=(struct trllc *)(trh+1);
hdr_len = sizeof(struct trh_hdr) + sizeof(struct trllc);
trh = (struct trh_hdr *)skb_push(skb, hdr_len);
trllc = (struct trllc *)(trh+1);
trllc->dsap = trllc->ssap = EXTENDED_SAP;
trllc->llc = UI_CMD;
trllc->protid[0] = trllc->protid[1] = trllc->protid[2] = 0x00;
trllc->ethertype = htons(type);
}
else
{
hdr_len = sizeof(struct trh_hdr);
trh = (struct trh_hdr *)skb_push(skb, hdr_len);
}
trh->ac=AC;
trh->fc=LLC_FRAME;
if(saddr)
memcpy(trh->saddr,saddr,dev->addr_len);
else
memcpy(trh->saddr,dev->dev_addr,dev->addr_len);
/*
* Build the destination and then source route the frame
*/
if(daddr)
{
memcpy(trh->daddr,daddr,dev->addr_len);
tr_source_route(skb,trh,dev);
return(hdr_len);
}
return -hdr_len;
}
/*
* A neighbour discovery of some species (eg arp) has completed. We
* can now send the packet.
*/
int tr_rebuild_header(struct sk_buff *skb)
{
struct trh_hdr *trh=(struct trh_hdr *)skb->data;
struct trllc *trllc=(struct trllc *)(skb->data+sizeof(struct trh_hdr));
struct net_device *dev = skb->dev;
/*
* FIXME: We don't yet support IPv6 over token rings
*/
if(trllc->ethertype != htons(ETH_P_IP)) {
printk("tr_rebuild_header: Don't know how to resolve type %04X addresses ?\n",(unsigned int)htons(trllc->ethertype));
return 0;
}
#ifdef CONFIG_INET
if(arp_find(trh->daddr, skb)) {
return 1;
}
else
#endif
{
tr_source_route(skb,trh,dev);
return 0;
}
}
/*
* Some of this is a bit hackish. We intercept RIF information
* used for source routing. We also grab IP directly and don't feed
* it via SNAP.
*/
unsigned short tr_type_trans(struct sk_buff *skb, struct net_device *dev)
{
struct trh_hdr *trh=(struct trh_hdr *)skb->data;
struct trllc *trllc;
unsigned riflen=0;
skb->mac.raw = skb->data;
if(trh->saddr[0] & TR_RII)
riflen = (ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8;
trllc = (struct trllc *)(skb->data+sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
skb_pull(skb,sizeof(struct trh_hdr)-TR_MAXRIFLEN+riflen);
if(*trh->daddr & 0x80)
{
if(!memcmp(trh->daddr,dev->broadcast,TR_ALEN))
skb->pkt_type=PACKET_BROADCAST;
else
skb->pkt_type=PACKET_MULTICAST;
}
else if ( (trh->daddr[0] & 0x01) && (trh->daddr[1] & 0x00) && (trh->daddr[2] & 0x5E))
{
skb->pkt_type=PACKET_MULTICAST;
}
else if(dev->flags & IFF_PROMISC)
{
if(memcmp(trh->daddr, dev->dev_addr, TR_ALEN))
skb->pkt_type=PACKET_OTHERHOST;
}
if ((skb->pkt_type != PACKET_BROADCAST) &&
(skb->pkt_type != PACKET_MULTICAST))
tr_add_rif_info(trh,dev) ;
/*
* Strip the SNAP header from ARP packets since we don't
* pass them through to the 802.2/SNAP layers.
*/
if (trllc->dsap == EXTENDED_SAP &&
(trllc->ethertype == ntohs(ETH_P_IP) ||
trllc->ethertype == ntohs(ETH_P_ARP)))
{
skb_pull(skb, sizeof(struct trllc));
return trllc->ethertype;
}
return ntohs(ETH_P_802_2);
}
/*
* We try to do source routing...
*/
static void tr_source_route(struct sk_buff *skb,struct trh_hdr *trh,struct net_device *dev)
{
int i, slack;
unsigned int hash;
rif_cache entry;
unsigned char *olddata;
unsigned char mcast_func_addr[] = {0xC0,0x00,0x00,0x04,0x00,0x00};
unsigned long flags ;
spin_lock_irqsave(&rif_lock,flags);
/*
* Broadcasts are single route as stated in RFC 1042
*/
if( (!memcmp(&(trh->daddr[0]),&(dev->broadcast[0]),TR_ALEN)) ||
(!memcmp(&(trh->daddr[0]),&(mcast_func_addr[0]), TR_ALEN)) )
{
trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
| TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
trh->saddr[0]|=TR_RII;
}
else
{
for(i=0,hash=0;i<TR_ALEN;hash+=trh->daddr[i++]);
hash&=RIF_TABLE_SIZE-1;
/*
* Walk the hash table and look for an entry
*/
for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->daddr[0]),TR_ALEN);entry=entry->next);
/*
* If we found an entry we can route the frame.
*/
if(entry)
{
#if TR_SR_DEBUG
printk("source routing for %02X:%02X:%02X:%02X:%02X:%02X\n",trh->daddr[0],
trh->daddr[1],trh->daddr[2],trh->daddr[3],trh->daddr[4],trh->daddr[5]);
#endif
if(!entry->local_ring && (ntohs(entry->rcf) & TR_RCF_LEN_MASK) >> 8)
{
trh->rcf=entry->rcf;
memcpy(&trh->rseg[0],&entry->rseg[0],8*sizeof(unsigned short));
trh->rcf^=htons(TR_RCF_DIR_BIT);
trh->rcf&=htons(0x1fff); /* Issam Chehab <ichehab@madge1.demon.co.uk> */
trh->saddr[0]|=TR_RII;
#if TR_SR_DEBUG
printk("entry found with rcf %04x\n", entry->rcf);
}
else
{
printk("entry found but without rcf length, local=%02x\n", entry->local_ring);
#endif
}
entry->last_used=jiffies;
}
else
{
/*
* Without the information we simply have to shout
* on the wire. The replies should rapidly clean this
* situation up.
*/
trh->rcf=htons((((sizeof(trh->rcf)) << 8) & TR_RCF_LEN_MASK)
| TR_RCF_FRAME2K | TR_RCF_LIMITED_BROADCAST);
trh->saddr[0]|=TR_RII;
#if TR_SR_DEBUG
printk("no entry in rif table found - broadcasting frame\n");
#endif
}
}
/* Compress the RIF here so we don't have to do it in the driver(s) */
if (!(trh->saddr[0] & 0x80))
slack = 18;
else
slack = 18 - ((ntohs(trh->rcf) & TR_RCF_LEN_MASK)>>8);
olddata = skb->data;
spin_unlock_irqrestore(&rif_lock,flags);
skb_pull(skb, slack);
memmove(skb->data, olddata, sizeof(struct trh_hdr) - slack);
}
/*
* We have learned some new RIF information for our source
* routing.
*/
static void tr_add_rif_info(struct trh_hdr *trh, struct net_device *dev)
{
int i;
unsigned int hash, rii_p = 0;
rif_cache entry;
spin_lock_bh(&rif_lock);
/*
* Firstly see if the entry exists
*/
if(trh->saddr[0] & TR_RII)
{
trh->saddr[0]&=0x7f;
if (((ntohs(trh->rcf) & TR_RCF_LEN_MASK) >> 8) > 2)
{
rii_p = 1;
}
}
for(i=0,hash=0;i<TR_ALEN;hash+=trh->saddr[i++]);
hash&=RIF_TABLE_SIZE-1;
for(entry=rif_table[hash];entry && memcmp(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);entry=entry->next);
if(entry==NULL)
{
#if TR_SR_DEBUG
printk("adding rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n",
trh->saddr[0],trh->saddr[1],trh->saddr[2],
trh->saddr[3],trh->saddr[4],trh->saddr[5],
ntohs(trh->rcf));
#endif
/*
* Allocate our new entry. A failure to allocate loses
* use the information. This is harmless.
*
* FIXME: We ought to keep some kind of cache size
* limiting and adjust the timers to suit.
*/
entry=kmalloc(sizeof(struct rif_cache_s),GFP_ATOMIC);
if(!entry)
{
printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n");
spin_unlock_bh(&rif_lock);
return;
}
memcpy(&(entry->addr[0]),&(trh->saddr[0]),TR_ALEN);
entry->iface = dev->ifindex;
entry->next=rif_table[hash];
entry->last_used=jiffies;
rif_table[hash]=entry;
if (rii_p)
{
entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
entry->local_ring = 0;
trh->saddr[0]|=TR_RII; /* put the routing indicator back for tcpdump */
}
else
{
entry->local_ring = 1;
}
}
else /* Y. Tahara added */
{
/*
* Update existing entries
*/
if (!entry->local_ring)
if (entry->rcf != (trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK)) &&
!(trh->rcf & htons(TR_RCF_BROADCAST_MASK)))
{
#if TR_SR_DEBUG
printk("updating rif_entry: addr:%02X:%02X:%02X:%02X:%02X:%02X rcf:%04X\n",
trh->saddr[0],trh->saddr[1],trh->saddr[2],
trh->saddr[3],trh->saddr[4],trh->saddr[5],
ntohs(trh->rcf));
#endif
entry->rcf = trh->rcf & htons((unsigned short)~TR_RCF_BROADCAST_MASK);
memcpy(&(entry->rseg[0]),&(trh->rseg[0]),8*sizeof(unsigned short));
}
entry->last_used=jiffies;
}
spin_unlock_bh(&rif_lock);
}
/*
* Scan the cache with a timer and see what we need to throw out.
*/
static void rif_check_expire(unsigned long dummy)
{
int i;
unsigned long now=jiffies;
unsigned long flags ;
spin_lock_irqsave(&rif_lock,flags);
for(i=0; i < RIF_TABLE_SIZE;i++)
{
rif_cache entry, *pentry=rif_table+i;
while((entry=*pentry))
{
/*
* Out it goes
*/
if((now-entry->last_used) > sysctl_tr_rif_timeout)
{
*pentry=entry->next;
kfree(entry);
}
else
pentry=&entry->next;
}
}
spin_unlock_irqrestore(&rif_lock,flags);
/*
* Reset the timer
*/
mod_timer(&rif_timer, jiffies+sysctl_tr_rif_timeout);
}
/*
* Generate the /proc/net information for the token ring RIF
* routing.
*/
#ifndef CONFIG_PROC_FS
static int rif_get_info(char *buffer,char **start, off_t offset, int length) { return 0;}
#else
static int rif_get_info(char *buffer,char **start, off_t offset, int length)
{
int len=0;
off_t begin=0;
off_t pos=0;
int size,i,j,rcf_len,segment,brdgnmb;
unsigned long now=jiffies;
rif_cache entry;
size=sprintf(buffer,
"if TR address TTL rcf routing segments\n");
pos+=size;
len+=size;
spin_lock_bh(&rif_lock);
for(i=0;i < RIF_TABLE_SIZE;i++)
{
for(entry=rif_table[i];entry;entry=entry->next) {
struct net_device *dev = __dev_get_by_index(entry->iface);
size=sprintf(buffer+len,"%s %02X:%02X:%02X:%02X:%02X:%02X %7li ",
dev?dev->name:"?",entry->addr[0],entry->addr[1],entry->addr[2],entry->addr[3],entry->addr[4],entry->addr[5],
sysctl_tr_rif_timeout-(now-entry->last_used));
len+=size;
pos=begin+len;
if (entry->local_ring)
size=sprintf(buffer+len,"local\n");
else {
size=sprintf(buffer+len,"%04X", ntohs(entry->rcf));
rcf_len = ((ntohs(entry->rcf) & TR_RCF_LEN_MASK)>>8)-2;
if (rcf_len)
rcf_len >>= 1;
for(j = 1; j < rcf_len; j++) {
if(j==1) {
segment=ntohs(entry->rseg[j-1])>>4;
len+=size;
pos=begin+len;
size=sprintf(buffer+len," %03X",segment);
};
segment=ntohs(entry->rseg[j])>>4;
brdgnmb=ntohs(entry->rseg[j-1])&0x00f;
len+=size;
pos=begin+len;
size=sprintf(buffer+len,"-%01X-%03X",brdgnmb,segment);
}
len+=size;
pos=begin+len;
size=sprintf(buffer+len,"\n");
}
len+=size;
pos=begin+len;
if(pos<offset)
{
len=0;
begin=pos;
}
if(pos>offset+length)
break;
}
if(pos>offset+length)
break;
}
spin_unlock_bh(&rif_lock);
*start=buffer+(offset-begin); /* Start of wanted data */
len-=(offset-begin); /* Start slop */
if(len>length)
len=length; /* Ending slop */
if (len<0)
len=0;
return len;
}
#endif
/*
* Called during bootup. We don't actually have to initialise
* too much for this.
*/
static int __init rif_init(void)
{
rif_timer.expires = RIF_TIMEOUT;
rif_timer.data = 0L;
rif_timer.function = rif_check_expire;
init_timer(&rif_timer);
add_timer(&rif_timer);
proc_net_create("tr_rif",0,rif_get_info);
return 0;
}
module_init(rif_init);
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