#include "u.h"#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "io.h" #include "ip.h" extern int debugload; uchar broadcast[Eaddrlen] = {	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,}; static ushort tftpport = 5000;static int Id = 1;static Netaddr myaddr;static Netaddr server; typedef struct {	uchar	header[4];	uchar	data[Segsize];} Tftp;static Tftp tftpb; static voidhnputs(uchar *ptr, ushort val){	ptr[0] = val>>8;	ptr[1] = val;} static voidhnputl(uchar *ptr, ulong val){	ptr[0] = val>>24;	ptr[1] = val>>16;	ptr[2] = val>>8;	ptr[3] = val;} static ulongnhgetl(uchar *ptr){	return ((ptr[0]<<24) | (ptr[1]<<16) | (ptr[2]<<8) | ptr[3]);} static ushortnhgets(uchar *ptr){	return ((ptr[0]<<8) | ptr[1]);} static	short	endian	= 1;static	char*	aendian	= (char*)&endian;#define	LITTLE	*aendian static ushortptcl_csum(void *a, int len){	uchar *addr;	ulong t1, t2;	ulong losum, hisum, mdsum, x; 	addr = a;	losum = 0;	hisum = 0;	mdsum = 0; 	x = 0;	if((ulong)addr & 1) {		if(len) {			hisum += addr[0];			len--;			addr++;		}		x = 1;	}	while(len >= 16) {		t1 = *(ushort*)(addr+0);		t2 = *(ushort*)(addr+2);	mdsum += t1;		t1 = *(ushort*)(addr+4);	mdsum += t2;		t2 = *(ushort*)(addr+6);	mdsum += t1;		t1 = *(ushort*)(addr+8);	mdsum += t2;		t2 = *(ushort*)(addr+10);	mdsum += t1;		t1 = *(ushort*)(addr+12);	mdsum += t2;		t2 = *(ushort*)(addr+14);	mdsum += t1;		mdsum += t2;		len -= 16;		addr += 16;	}	while(len >= 2) {		mdsum += *(ushort*)addr;		len -= 2;		addr += 2;	}	if(x) {		if(len)			losum += addr[0];		if(LITTLE)			losum += mdsum;		else			hisum += mdsum;	} else {		if(len)			hisum += addr[0];		if(LITTLE)			hisum += mdsum;		else			losum += mdsum;	} 	losum += hisum >> 8;	losum += (hisum & 0xff) << 8;	while(hisum = losum>>16)		losum = hisum + (losum & 0xffff); 	return ~losum;} static ushortip_csum(uchar *addr){	int len;	ulong sum = 0; 	len = (addr[0]&0xf)<<2; 	while(len > 0) {		sum += addr[0]<<8 | addr[1] ;		len -= 2;		addr += 2;	} 	sum = (sum & 0xffff) + (sum >> 16);	sum = (sum & 0xffff) + (sum >> 16);	return (sum^0xffff);} enum {	/* this is only true of IPv4, but we're not doing v6 yet */	Min_udp_payload = ETHERMINTU - ETHERHDRSIZE - UDP_HDRSIZE,}; static voidudpsend(int ctlrno, Netaddr *a, void *data, int dlen){	char payload[ETHERMAXTU];	Udphdr *uh;	Etherhdr *ip;	Etherpkt pkt;	int len, ptcllen; 	/*	 * if packet is too short, make it longer rather than relying	 * on ethernet interface or lower layers to pad it.	 */	if (dlen < Min_udp_payload) {		memmove(payload, data, dlen);		data = payload;		dlen = Min_udp_payload;	} 	uh = (Udphdr*)&pkt; 	memset(uh, 0, sizeof(Etherpkt));	memmove(uh->udpcksum+sizeof(uh->udpcksum), data, dlen); 	/*	 * UDP portion	 */	ptcllen = dlen + (UDP_HDRSIZE-UDP_PHDRSIZE);	uh->ttl = 0;	uh->udpproto = IP_UDPPROTO;	uh->frag[0] = 0;	uh->frag[1] = 0;	hnputs(uh->udpplen, ptcllen);	hnputl(uh->udpsrc, myaddr.ip);	hnputs(uh->udpsport, myaddr.port);	hnputl(uh->udpdst, a->ip);	hnputs(uh->udpdport, a->port);	hnputs(uh->udplen, ptcllen);	uh->udpcksum[0] = 0;	uh->udpcksum[1] = 0;	dlen = (dlen+1)&~1;	hnputs(uh->udpcksum, ptcl_csum(&uh->ttl, dlen+UDP_HDRSIZE)); 	/*	 * IP portion	 */	ip = (Etherhdr*)&pkt;	len = UDP_EHSIZE+UDP_HDRSIZE+dlen;		/* non-descriptive names */	ip->vihl = IP_VER|IP_HLEN;	ip->tos = 0;	ip->ttl = 255;	hnputs(ip->length, len-ETHER_HDR);	hnputs(ip->id, Id++);	ip->frag[0] = 0;	ip->frag[1] = 0;	ip->cksum[0] = 0;	ip->cksum[1] = 0;	hnputs(ip->cksum, ip_csum(&ip->vihl)); 	/*	 * Ethernet MAC portion	 */	hnputs(ip->type, ET_IP);	memmove(ip->d, a->ea, sizeof(ip->d)); if(debug) {	print("udpsend ");}	ethertxpkt(ctlrno, &pkt, len, Timeout);} static voidnak(int ctlrno, Netaddr *a, int code, char *msg, int report){	int n;	char buf[128]; 	buf[0] = 0;	buf[1] = Tftp_ERROR;	buf[2] = 0;	buf[3] = code;	strcpy(buf+4, msg);	n = strlen(msg) + 4 + 1;	udpsend(ctlrno, a, buf, n);	if(report)		print("\ntftp: error(%d): %s\n", code, msg);} static intudprecv(int ctlrno, Netaddr *a, void *data, int dlen){	int n, len;	ushort csm;	Udphdr *h;	ulong addr, timo;	Etherpkt pkt;	static int rxactive; 	if(rxactive == 0)		timo = 1000;	else		timo = Timeout;	timo += TK2MS(m->ticks);	while(timo > TK2MS(m->ticks)){		n = etherrxpkt(ctlrno, &pkt, timo-TK2MS(m->ticks));		if(n <= 0)			continue; 		h = (Udphdr*)&pkt;		if(debug)			print("udprecv %E to %E...\n", h->s, h->d); 		if(nhgets(h->type) != ET_IP) {			if(debug)				print("not ip...");			continue;		} 		if(ip_csum(&h->vihl)) {			print("ip chksum error\n");			continue;		}		if(h->vihl != (IP_VER|IP_HLEN)) {			print("ip bad vers/hlen\n");			continue;		} 		if(h->udpproto != IP_UDPPROTO) {			if(debug)				print("not udp (%d)...", h->udpproto);			continue;		} 		if(debug)			print("okay udp..."); 		h->ttl = 0;		len = nhgets(h->udplen);		hnputs(h->udpplen, len); 		if(nhgets(h->udpcksum)) {			csm = ptcl_csum(&h->ttl, len+UDP_PHDRSIZE);			if(csm != 0) {				print("udp chksum error csum #%4ux len %d\n",					csm, n);				break;			}		} 		if(a->port != 0 && nhgets(h->udpsport) != a->port) {			if(debug)				print("udpport %ux not %ux\n",					nhgets(h->udpsport), a->port);			continue;		} 		addr = nhgetl(h->udpsrc);		if(a->ip != Bcastip && a->ip != addr) {			if(debug)				print("bad ip %lux not %lux\n", addr, a->ip);			continue;		} 		len -= UDP_HDRSIZE-UDP_PHDRSIZE;		if(len > dlen) {			print("udp: packet too big: %d > %d; from addr %E\n",				len, dlen, h->udpsrc);			continue;		} 		memmove(data, h->udpcksum+sizeof(h->udpcksum), len);		a->ip = addr;		a->port = nhgets(h->udpsport);		memmove(a->ea, pkt.s, sizeof(a->ea)); 		rxactive = 1;		return len;	} 	return 0;} static int tftpblockno; /* * format of a request packet, from the RFC: *            2 bytes     string    1 byte     string   1 byte            ------------------------------------------------           | Opcode |  Filename  |   0  |    Mode    |   0  |            ------------------------------------------------ */static inttftpopen(int ctlrno, Netaddr *a, char *name, Tftp *tftp){	int i, len, rlen, oport;	char buf[Segsize+2]; 	buf[0] = 0;	buf[1] = Tftp_READ;	len = 2 + sprint(buf+2, "%s", name) + 1;	len += sprint(buf+len, "octet") + 1; 	oport = a->port;	for(i = 0; i < 5; i++){		a->port = oport;		udpsend(ctlrno, a, buf, len);		a->port = 0;		if((rlen = udprecv(ctlrno, a, tftp, sizeof(Tftp))) < sizeof(tftp->header))			continue; 		switch((tftp->header[0]<<8)|tftp->header[1]){ 		case Tftp_ERROR:			print("tftpopen: error (%d): %s\n",				(tftp->header[2]<<8)|tftp->header[3], (char*)tftp->data);			return -1; 		case Tftp_DATA:			tftpblockno = 1;			len = (tftp->header[2]<<8)|tftp->header[3];			if(len != tftpblockno){				print("tftpopen: block error: %d\n", len);				nak(ctlrno, a, 1, "block error", 0);				return -1;			}			rlen -= sizeof(tftp->header);			if(rlen < Segsize){				/* ACK now, in case we don't later */				buf[0] = 0;				buf[1] = Tftp_ACK;				buf[2] = tftpblockno>>8;				buf[3] = tftpblockno;				udpsend(ctlrno, a, buf, sizeof(tftp->header));			}			return rlen;		}	} 	print("tftpopen: failed to connect to server\n");	return -1;} static inttftpread(int ctlrno, Netaddr *a, Tftp *tftp, int dlen){	uchar buf[4];	int try, blockno, len; 	dlen += sizeof(tftp->header); 	for(try = 0; try < 10; try++) {		buf[0] = 0;		buf[1] = Tftp_ACK;		buf[2] = tftpblockno>>8;		buf[3] = tftpblockno; 		udpsend(ctlrno, a, buf, sizeof(buf));		len = udprecv(ctlrno, a, tftp, dlen);		if(len <= sizeof(tftp->header)){			if(debug)				print("tftpread: too short %d <= %d\n",					len, sizeof(tftp->header));			continue;		}		blockno = (tftp->header[2]<<8)|tftp->header[3];		if(blockno <= tftpblockno){			if(debug)				print("tftpread: blkno %d <= %d\n",					blockno, tftpblockno);			continue;		} 		if(blockno == tftpblockno+1) {			tftpblockno++;			if(len < dlen) {	/* last packet; send final ack */				tftpblockno++;				buf[0] = 0;				buf[1] = Tftp_ACK;				buf[2] = tftpblockno>>8;				buf[3] = tftpblockno;				udpsend(ctlrno, a, buf, sizeof(buf));			}			return len-sizeof(tftp->header);		}		print("tftpread: block error: %d, expected %d\n",			blockno, tftpblockno+1);	} 	return -1;} static intbootpopen(int ctlrno, char *file, Bootp *rep, int dotftpopen){	Bootp req;	int i, n;	uchar *ea;	char name[128], *filename, *sysname; 	if (debugload)		print("bootpopen: ether%d!%s...", ctlrno, file);	if((ea = etheraddr(ctlrno)) == 0){		print("invalid ctlrno %d\n", ctlrno);		return -1;	} 	filename = 0;	sysname = 0;	if(file && *file){		strcpy(name, file);		if(filename = strchr(name, '!')){			sysname = name;			*filename++ = 0;		}		else			filename = name;	} 	memset(&req, 0, sizeof(req));	req.op = Bootrequest;	req.htype = 1;			/* ethernet */	req.hlen = Eaddrlen;		/* ethernet */	memmove(req.chaddr, ea, Eaddrlen);	if(filename != nil)		strncpy(req.file, filename, sizeof(req.file));	if(sysname != nil)		strncpy(req.sname, sysname, sizeof(req.sname)); 	myaddr.ip = 0;	myaddr.port = BPportsrc;	memmove(myaddr.ea, ea, Eaddrlen); 	etherrxflush(ctlrno);	for(i = 0; i < 10; i++) {		server.ip = Bcastip;		server.port = BPportdst;		memmove(server.ea, broadcast, sizeof(server.ea));		udpsend(ctlrno, &server, &req, sizeof(req));		if(udprecv(ctlrno, &server, rep, sizeof(*rep)) <= 0)			continue;		if(memcmp(req.chaddr, rep->chaddr, Eaddrlen))			continue;		if(rep->htype != 1 || rep->hlen != Eaddrlen)			continue;		if(sysname == 0 || strcmp(sysname, rep->sname) == 0)			break;	}	if(i >= 10) {		print("bootp timed out\n");		return -1;	} 	if(!dotftpopen)		return 0;

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