/* * 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/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/jiffies.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/seq_file.h> #include <linux/init.h> #include <net/arp.h> #include <net/net_namespace.h> 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 /* * Each RIF entry we learn is kept this way */ struct rif_cache { unsigned char addr[TR_ALEN]; int iface; __be16 rcf; __be16 rseg[8]; struct 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. */ static struct rif_cache *rif_table[RIF_TABLE_SIZE]; static DEFINE_SPINLOCK(rif_lock); /* * Garbage disposal timer. */ static struct timer_list rif_timer; int sysctl_tr_rif_timeout = 60*10*HZ; static inline unsigned long rif_hash(const unsigned char *addr) { unsigned long x; x = addr[0]; x = (x << 2) ^ addr[1]; x = (x << 2) ^ addr[2]; x = (x << 2) ^ addr[3]; x = (x << 2) ^ addr[4]; x = (x << 2) ^ addr[5]; x ^= x >> 8; return x & (RIF_TABLE_SIZE - 1); } /* * Put the headers on a token ring packet. Token ring source routing * makes this a little more exciting than on ethernet. */ static int tr_header(struct sk_buff *skb, struct net_device *dev, unsigned short type, const void *daddr, const void *saddr, unsigned len) { struct trh_hdr *trh; int hdr_len; /* * Add the 802.2 SNAP header if IP as the IPv4/IPv6 code calls * dev->hard_header directly. */ if (type == ETH_P_IP || type == ETH_P_IPV6 || type == ETH_P_ARP) { struct trllc *trllc; 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. */ static 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", ntohs(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. */ __be16 tr_type_trans(struct sk_buff *skb, struct net_device *dev) { struct trh_hdr *trh; struct trllc *trllc; unsigned riflen=0; skb->dev = dev; skb_reset_mac_header(skb); trh = tr_hdr(skb); 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 == htons(ETH_P_IP) || trllc->ethertype == htons(ETH_P_IPV6) || trllc->ethertype == htons(ETH_P_ARP))) { skb_pull(skb, sizeof(struct trllc)); return trllc->ethertype; } return htons(ETH_P_TR_802_2); } /* * We try to do source routing... */ void tr_source_route(struct sk_buff *skb,struct trh_hdr *trh, struct net_device *dev) { int slack; unsigned int hash; struct rif_cache *entry; unsigned char *olddata; unsigned long flags; static const unsigned char mcast_func_addr[] = {0xC0,0x00,0x00,0x04,0x00,0x00}; 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 { hash = rif_hash(trh->daddr); /* * 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 { DECLARE_MAC_BUF(mac); printk("source routing for %s\n",print_mac(mac, trh->daddr)); } #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) { unsigned int hash, rii_p = 0; unsigned long flags; struct rif_cache *entry; unsigned char saddr0; spin_lock_irqsave(&rif_lock, flags); saddr0 = trh->saddr[0]; /* * 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; } } hash = rif_hash(trh->saddr); 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 DECLARE_MAC_BUF(mac); printk("adding rif_entry: addr:%s rcf:%04X\n", print_mac(mac, trh->saddr), 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),GFP_ATOMIC); if(!entry) { printk(KERN_DEBUG "tr.c: Couldn't malloc rif cache entry !\n"); spin_unlock_irqrestore(&rif_lock, flags); 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; } 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 { DECLARE_MAC_BUF(mac); printk("updating rif_entry: addr:%s rcf:%04X\n", print_mac(mac, trh->saddr), 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; } trh->saddr[0]=saddr0; /* put the routing indicator back for tcpdump */ spin_unlock_irqrestore(&rif_lock, flags); } /* * 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 flags, next_interval = jiffies + sysctl_tr_rif_timeout/2; spin_lock_irqsave(&rif_lock, flags); for(i =0; i < RIF_TABLE_SIZE; i++) { struct rif_cache *entry, **pentry; pentry = rif_table+i; while((entry=*pentry) != NULL) { unsigned long expires = entry->last_used + sysctl_tr_rif_timeout; if (time_before_eq(expires, jiffies)) { *pentry = entry->next; kfree(entry); } else { pentry = &entry->next; if (time_before(expires, next_interval)) next_interval = expires; } } } spin_unlock_irqrestore(&rif_lock, flags); mod_timer(&rif_timer, next_interval); } /* * Generate the /proc/net information for the token ring RIF * routing. */ #ifdef CONFIG_PROC_FS static struct rif_cache *rif_get_idx(loff_t pos) { int i; struct rif_cache *entry; loff_t off = 0; for(i = 0; i < RIF_TABLE_SIZE; i++) for(entry = rif_table[i]; entry; entry = entry->next) { if (off == pos) return entry; ++off; } return NULL; } static void *rif_seq_start(struct seq_file *seq, loff_t *pos) { spin_lock_irq(&rif_lock); return *pos ? rif_get_idx(*pos - 1) : SEQ_START_TOKEN; } static void *rif_seq_next(struct seq_file *seq, void *v, loff_t *pos) { int i; struct rif_cache *ent = v; ++*pos; if (v == SEQ_START_TOKEN) { i = -1; goto scan; } if (ent->next) return ent->next; i = rif_hash(ent->addr); scan: while (++i < RIF_TABLE_SIZE) { if ((ent = rif_table[i]) != NULL) return ent; } return NULL; } static void rif_seq_stop(struct seq_file *seq, void *v) { spin_unlock_irq(&rif_lock); } static int rif_seq_show(struct seq_file *seq, void *v) { int j, rcf_len, segment, brdgnmb; struct rif_cache *entry = v; DECLARE_MAC_BUF(mac); if (v == SEQ_START_TOKEN) seq_puts(seq, "if TR address TTL rcf routing segments\n"); else { struct net_device *dev = dev_get_by_index(&init_net, entry->iface); long ttl = (long) (entry->last_used + sysctl_tr_rif_timeout) - (long) jiffies; seq_printf(seq, "%s %s %7li ", dev?dev->name:"?", print_mac(mac, entry->addr), ttl/HZ); if (entry->local_ring) seq_puts(seq, "local\n"); else { seq_printf(seq, "%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; seq_printf(seq," %03X",segment); } segment=ntohs(entry->rseg[j])>>4; brdgnmb=ntohs(entry->rseg[j-1])&0x00f; seq_printf(seq,"-%01X-%03X",brdgnmb,segment); } seq_putc(seq, '\n'); } } return 0; } static const struct seq_operations rif_seq_ops = { .start = rif_seq_start, .next = rif_seq_next, .stop = rif_seq_stop, .show = rif_seq_show, }; static int rif_seq_open(struct inode *inode, struct file *file) { return seq_open(file, &rif_seq_ops); } static const struct file_operations rif_seq_fops = { .owner = THIS_MODULE, .open = rif_seq_open, .read = seq_read, .llseek = seq_lseek, .release = seq_release, }; #endif static const struct header_ops tr_header_ops = { .create = tr_header, .rebuild= tr_rebuild_header, }; static void tr_setup(struct net_device *dev) { /* * Configure and register */ dev->header_ops = &tr_header_ops; dev->type = ARPHRD_IEEE802_TR; dev->hard_header_len = TR_HLEN; dev->mtu = 2000; dev->addr_len = TR_ALEN; dev->tx_queue_len = 100; /* Long queues on tr */ memset(dev->broadcast,0xFF, TR_ALEN); /* New-style flags. */ dev->flags = IFF_BROADCAST | IFF_MULTICAST ; } /** * alloc_trdev - Register token ring device * @sizeof_priv: Size of additional driver-private structure to be allocated * for this token ring device * * Fill in the fields of the device structure with token ring-generic values. * * Constructs a new net device, complete with a private data area of * size @sizeof_priv. A 32-byte (not bit) alignment is enforced for * this private data area. */ struct net_device *alloc_trdev(int sizeof_priv) { return alloc_netdev(sizeof_priv, "tr%d", tr_setup); } /* * Called during bootup. We don't actually have to initialise * too much for this. */ static int __init rif_init(void) { init_timer(&rif_timer); rif_timer.expires = sysctl_tr_rif_timeout; rif_timer.data = 0L; rif_timer.function = rif_check_expire; add_timer(&rif_timer); proc_net_fops_create(&init_net, "tr_rif", S_IRUGO, &rif_seq_fops); return 0; } module_init(rif_init); EXPORT_SYMBOL(tr_type_trans); EXPORT_SYMBOL(alloc_trdev);