#include <u.h>#include <libc.h>#include <bio.h>#include <ip.h>#include <ndb.h>#include "arp.h"#include "bootp.h" int 	dbg;int	bootreq;int	bootctl;char	*sysname;Ipinfo	myiip;Ndb	*db;char	blog[] = "ipboot"; typedef struct Boottab Boottab;struct Boottab{	Ipinfo;	uchar	reply[4];		/* reply address */}; void		openlisten(void);void		fatal(int, char*, ...);void		warning(int, char*, ...);void		doreply(Bootp*, Boottab*);Boottab*	lookup(Bootp*, Udphdr*); #define TFTP "/lib/tftpd" voidmain(int argc, char **argv){	Bootp *boot;	Udphdr *up;	Boottab *f;	char *file;	char buf[2*1024];	uchar myip[4]; 	ARGBEGIN{	case 'd':		dbg++;		break;	default:		fprint(2, "usage: bootp [-d]\n");		exits("usage");	}ARGEND	USED(argc); USED(argv); 	fmtinstall('E', eipconv);	fmtinstall('I', eipconv); 	/* who am i? */	sysname = getenv("sysname");	if(sysname == 0)		fatal(0, "I must know my name!");	if(myipaddr(myip, "/net/udp") < 0)		fatal(0, "I must know my ip addr!"); 	/* get local info from the database */	db = ndbopen(0);	if(db == 0)		fatal(0, "can't open database\n");	sprint(buf, "%I", myip);	if(ipinfo(db, 0, buf, 0, &myiip) < 0)		fatal(0, "I'm not in network database!"); 	syslog(dbg, blog, "started"); 	switch(rfork(RFNOTEG|RFPROC|RFFDG)) {	case -1:		fatal(1, "fork");	case 0:		break;	default:		exits(0);	} 	openlisten();	chdir(TFTP); 	for(;;) {		read(bootreq, buf, sizeof(buf));		up = (Udphdr*)buf;		boot = (Bootp*)(buf+Udphdrsize);		if(boot->op != Bootrequest)			continue;		if(boot->htype != 1){			syslog(dbg, blog, "not ethernet %E\n", boot->chaddr);			continue;		} 		/*		 *  Answer the request if the client didn't specify another		 *  server and either we know the bootfile or the client		 *  specified one.		 */		if(boot->sname[0]==0 || strcmp(boot->sname, sysname)==0){			f = lookup(boot, up);			file = boot->file;			if(*file == 0 && f)				file = f->bootf; 			/*			 *  unless we're specificly targeted or have the			 *  boot file, don't answer			 */			if(boot->sname[0]==0 && (*file == 0 || access(file, 4) < 0))				continue; 			if(f && file[0]){				doreply(boot, f);			} else {				if(f)					syslog(dbg, blog, "no bootfile for %I %E",						f->ipaddr, f->etheraddr);				else					syslog(dbg, blog, "no entry for %I %E",						boot->ciaddr, boot->chaddr); 			}		}	}} /* *  lookup info about a client in the database.  The client may have supplied *  an hardware address or an ip adress and a hardware address. */Boottab*lookup(Bootp *b, Udphdr *up){	static Boottab bt;	char ether[32];	char ip[32];	uchar x[4], y[4], z[4];	Ndbtuple *t, *nt;	Ndbs s;	int i, isether; 	memset(&bt, 0, sizeof(Boottab)); 	isether = 0;	for(i = 0; i < sizeof(b->chaddr); i++)		isether |= b->chaddr[i];	sprint(ether, "%E", b->chaddr);	sprint(ip, "%I", b->ciaddr);	if(ipinfo(db, isether ? ether : 0, *b->ciaddr ? ip : 0, 0, &bt) < 0)		return 0; 	maskip(up->ipaddr, bt.ipmask, x);	if(*up->ipaddr != 0 && memcmp(x, bt.ipnet, sizeof(bt.ipnet)) != 0){		/*		 *  the request comes from a different net or subnet than		 *  the ip address we found, look for a different answer		 *  that matches both ether address and network.		 */		t = ndbsearch(db, &s, "ether", ether);		while(t){			for(nt = t; nt; nt = nt->entry){				if(strcmp(nt->attr, "ip") == 0){					parseip(y, nt->val);					maskip(y, bt.ipmask, z);					if(memcmp(x, z, sizeof(x)) == 0){						ipinfo(db, 0, nt->val, 0, &bt);						break;					}				}			}			ndbfree(t);			if(nt)				break;			t = ndbsnext(&s, "ether", ether);		}	}		 	/* it knows who it it, reply directly */	memmove(bt.reply, bt.ipaddr, sizeof(bt.reply)); 	return &bt;} voidarpenter(uchar *ip, uchar *ether){	Arpentry a;	int f; 	/* plan 9 */	f = open("#a/arp/data", OWRITE);	if(f >= 0){		memmove(a.etaddr, ether, sizeof(a.etaddr));		memmove(a.ipaddr, ip, sizeof(a.ipaddr));		if(write(f, &a, sizeof(a)) < 0)			syslog(dbg, blog, "write arp: %r\n");		close(f);		return;	} 	/* brazil */	f = open("/net/arp", OWRITE);	if(f >= 0){		fprint(f, "add %I %E", ip, ether);		close(f);		return;	} 	syslog(dbg, blog, "open arp: %r\n");} voiddoreply(Bootp *boot, Boottab *tab){	Udphdr *up;	Bootp *rp;	char buf[2*1024];	int i, n; 	up = (Udphdr*)buf;	rp = (Bootp*)(buf+Udphdrsize);	boot->sname[sizeof(boot->sname)-1] = '\0'; 	memmove(rp, boot, sizeof(Bootp));	rp->op = Bootreply; 	/* the client always best know his ether address */	n = 0;	for(i = 0; i < sizeof(boot->chaddr); i++)		n |= boot->chaddr[i];	if(n){		if(tab)			arpenter(tab->ipaddr, boot->chaddr); 		else			arpenter(boot->ciaddr, boot->chaddr);	} 	/* but we best know the ip addresses */	if(tab)		memmove(rp->yiaddr, tab->ipaddr, sizeof(tab->ipaddr));	else		memmove(rp->yiaddr, boot->ciaddr, sizeof(rp->yiaddr));	memmove(rp->siaddr, myiip.ipaddr, sizeof(myiip.ipaddr));	if(tab)		memmove(rp->giaddr, tab->gwip, sizeof(rp->giaddr));	else		memset(rp->giaddr, 0, sizeof(rp->giaddr)); 	strcpy(rp->sname, sysname);	if(boot->file[0] != '\0') {		if(boot->file[0] != '/')			sprint(rp->file, "%s/%s", TFTP, boot->file);	} else if(tab)		strcpy(rp->file, tab->bootf);	else		strcpy(rp->file, "no file"); 	if(tab && strncmp(rp->vend, "p9  ", 4) == 0)		sprint(rp->vend, "p9  %I %I %I %I", tab->ipmask, tab->fsip,			tab->auip, tab->gwip); 	syslog(dbg, blog, "reply to %I %E %s %s", rp->yiaddr, boot->chaddr,		rp->file, rp->vend); 	/*	 *  create reply address	 */	if(tab)		memmove(up->ipaddr, tab->reply, sizeof(up->ipaddr));	else		memmove(up->ipaddr, rp->yiaddr, sizeof(up->ipaddr));	up->port[0] = 0;	up->port[1] = 68; 	/*	 *  send the reply	 */	n = write(bootreq, buf, sizeof(Bootp)+Udphdrsize);	if(n < 0)		warning(1, "can't reply to %I", up->ipaddr);} voidopenlisten(void){	char data[128];	char devdir[40]; 	bootctl = announce("udp!*!bootp", devdir);	if(bootctl < 0)		fatal(1, "can't announce");	if(write(bootctl, "headers", sizeof("headers")) < 0)		fatal(1, "can't set header mode"); 	sprint(data, "%s/data", devdir); 	bootreq = open(data, ORDWR);	if(bootreq < 0)		fatal(1, "open udp data");} voidfatal(int syserr, char *fmt, ...){	char buf[ERRLEN], sysbuf[ERRLEN]; 	doprint(buf, buf+sizeof(buf), fmt, (&fmt+1));	if(syserr) {		errstr(sysbuf);		fprint(2, "bootp: %s: %s\n", buf, sysbuf);	}	else		fprint(2, "bootp: %s\n", buf);	exits(buf);} voidwarning(int syserr, char *fmt, ...){	char buf[ERRLEN], sysbuf[ERRLEN]; 	doprint(buf, buf+sizeof(buf), fmt, (&fmt+1));	if(syserr) {		errstr(sysbuf);		fprint(2, "bootp: %s: %s\n", buf, sysbuf);	}	else		fprint(2, "bootp: %s\n", buf);}