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[/] [or1k/] [trunk/] [rc203soc/] [sw/] [uClinux/] [net/] [ethernet/] [eth.c] - Rev 1772
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/* * INET An implementation of the TCP/IP protocol suite for the LINUX * operating system. INET is implemented using the BSD Socket * interface as the means of communication with the user level. * * Ethernet-type device handling. * * Version: @(#)eth.c 1.0.7 05/25/93 * * Authors: Ross Biro, <bir7@leland.Stanford.Edu> * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG> * Mark Evans, <evansmp@uhura.aston.ac.uk> * Florian La Roche, <rzsfl@rz.uni-sb.de> * Alan Cox, <gw4pts@gw4pts.ampr.org> * * Fixes: * Mr Linux : Arp problems * Alan Cox : Generic queue tidyup (very tiny here) * Alan Cox : eth_header ntohs should be htons * Alan Cox : eth_rebuild_header missing an htons and * minor other things. * Tegge : Arp bug fixes. * Florian : Removed many unnecessary functions, code cleanup * and changes for new arp and skbuff. * Alan Cox : Redid header building to reflect new format. * Alan Cox : ARP only when compiled with CONFIG_INET * Greg Page : 802.2 and SNAP stuff. * Alan Cox : MAC layer pointers/new format. * Paul Gortmaker : eth_copy_and_sum shouldn't csum padding. * Alan Cox : Protect against forwarding explosions with * older network drivers and IFF_ALLMULTI. * Christer Weinigel : Better rebuild header message. * Russell King : eth_header_cache_bind and eth_header_cache_update * only compiled if CONFIG_INET is selected * * 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. */ #include <asm/segment.h> #include <asm/system.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/etherdevice.h> #include <linux/skbuff.h> #include <linux/errno.h> #include <linux/config.h> #include <net/arp.h> #include <net/sock.h> #include <asm/checksum.h> void eth_setup(char *str, int *ints) { struct device *d = dev_base; if (!str || !*str) return; while (d) { if (!strcmp(str,d->name)) { if (ints[0] > 0) d->irq=ints[1]; if (ints[0] > 1) d->base_addr=ints[2]; if (ints[0] > 2) d->mem_start=ints[3]; if (ints[0] > 3) d->mem_end=ints[4]; break; } d=d->next; } } /* * Create the Ethernet MAC header for an arbitrary protocol layer * * saddr=NULL means use device source address * daddr=NULL means leave destination address (eg unresolved arp) */ int eth_header(struct sk_buff *skb, struct device *dev, unsigned short type, void *daddr, void *saddr, unsigned len) { struct ethhdr *eth = (struct ethhdr *)skb_push(skb,ETH_HLEN); /* * Set the protocol type. For a packet of type ETH_P_802_3 we put the length * in here instead. It is up to the 802.2 layer to carry protocol information. */ if(type!=ETH_P_802_3) eth->h_proto = htons(type); else eth->h_proto = htons(len); /* * Set the source hardware address. */ if(saddr) memcpy(eth->h_source,saddr,dev->addr_len); else memcpy(eth->h_source,dev->dev_addr,dev->addr_len); /* * Anyway, the loopback-device should never use this function... */ if (dev->flags & IFF_LOOPBACK) { memset(eth->h_dest, 0, dev->addr_len); return(dev->hard_header_len); } if(daddr) { memcpy(eth->h_dest,daddr,dev->addr_len); return dev->hard_header_len; } return -dev->hard_header_len; } /* * Rebuild the Ethernet MAC header. This is called after an ARP * (or in future other address resolution) has completed on this * sk_buff. We now let ARP fill in the other fields. */ int eth_rebuild_header(void *buff, struct device *dev, unsigned long dst, struct sk_buff *skb) { struct ethhdr *eth = (struct ethhdr *)buff; /* * Only ARP/IP is currently supported */ if(eth->h_proto != htons(ETH_P_IP)) { printk(KERN_DEBUG "%s: unable to resolve type %X addresses.\n",dev->name,(int)eth->h_proto); memcpy(eth->h_source, dev->dev_addr, dev->addr_len); return 0; } /* * Try to get ARP to resolve the header. */ #ifdef CONFIG_INET return arp_find(eth->h_dest, dst, dev, dev->pa_addr, skb)? 1 : 0; #else return 0; #endif } /* * Determine the packet's protocol ID. The rule here is that we * assume 802.3 if the type field is short enough to be a length. * This is normal practice and works for any 'now in use' protocol. */ unsigned short eth_type_trans(struct sk_buff *skb, struct device *dev) { struct ethhdr *eth; unsigned char *rawp; skb->mac.raw=skb->data; skb_pull(skb,dev->hard_header_len); eth= skb->mac.ethernet; if(*eth->h_dest&1) { if(memcmp(eth->h_dest,dev->broadcast, ETH_ALEN)==0) skb->pkt_type=PACKET_BROADCAST; else skb->pkt_type=PACKET_MULTICAST; } /* * This ALLMULTI check should be redundant by 1.4 * so don't forget to remove it. */ else if(dev->flags&(IFF_PROMISC|IFF_ALLMULTI)) { if(memcmp(eth->h_dest,dev->dev_addr, ETH_ALEN)) skb->pkt_type=PACKET_OTHERHOST; } if (ntohs(eth->h_proto) >= 1536) return eth->h_proto; rawp = skb->data; /* * This is a magic hack to spot IPX packets. Older Novell breaks * the protocol design and runs IPX over 802.3 without an 802.2 LLC * layer. We look for FFFF which isn't a used 802.2 SSAP/DSAP. This * won't work for fault tolerant netware but does for the rest. */ if (*(unsigned short *)rawp == 0xFFFF) return htons(ETH_P_802_3); /* * Real 802.2 LLC */ return htons(ETH_P_802_2); } #ifdef CONFIG_INET /* * Upper level calls this function to bind hardware header cache entry. * If the call is successful, then corresponding Address Resolution Protocol * (maybe, not ARP) takes responsibility for updating cache content. */ void eth_header_cache_bind(struct hh_cache ** hhp, struct device *dev, unsigned short htype, __u32 daddr) { struct hh_cache *hh; if (htype != ETH_P_IP) { printk(KERN_DEBUG "eth_header_cache_bind: %04x cache is not implemented\n", htype); return; } if (arp_bind_cache(hhp, dev, htype, daddr)) return; if ((hh=*hhp) != NULL) { memcpy(hh->hh_data+6, dev->dev_addr, ETH_ALEN); hh->hh_data[12] = htype>>8; hh->hh_data[13] = htype&0xFF; } } /* * Called by Address Resolution module to notify changes in address. */ void eth_header_cache_update(struct hh_cache *hh, struct device *dev, unsigned char * haddr) { if (hh->hh_type != ETH_P_IP) { printk(KERN_DEBUG "eth_header_cache_update: %04x cache is not implemented\n", hh->hh_type); return; } memcpy(hh->hh_data, haddr, ETH_ALEN); hh->hh_uptodate = 1; } #endif /* * Copy from an ethernet device memory space to an sk_buff while checksumming if IP */ void eth_copy_and_sum(struct sk_buff *dest, unsigned char *src, int length, int base) { #ifdef CONFIG_IP_ROUTER memcpy(dest->data,src,length); #else struct ethhdr *eth; struct iphdr *iph; int ip_length; IS_SKB(dest); eth=(struct ethhdr *)src; if(eth->h_proto!=htons(ETH_P_IP)) { memcpy(dest->data,src,length); return; } /* * We have to watch for padded packets. The csum doesn't include the * padding, and there is no point in copying the padding anyway. * We have to use the smaller of length and ip_length because it * can happen that ip_length > length. */ memcpy(dest->data,src,sizeof(struct iphdr)+ETH_HLEN); /* ethernet is always >= 34 */ length -= sizeof(struct iphdr) + ETH_HLEN; iph=(struct iphdr*)(src+ETH_HLEN); ip_length = ntohs(iph->tot_len) - sizeof(struct iphdr); /* Also watch out for bogons - min IP size is 8 (rfc-1042) */ if ((ip_length <= length) && (ip_length > 7)) length=ip_length; dest->csum=csum_partial_copy(src+sizeof(struct iphdr)+ETH_HLEN,dest->data+sizeof(struct iphdr)+ETH_HLEN,length,base); dest->ip_summed=1; #endif }
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