/*  * This file is part of the UCB release of Plan 9. It is subject to the license * terms in the LICENSE file found in the top-level directory of this * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No * part of the UCB release of Plan 9, including this file, may be copied, * modified, propagated, or distributed except according to the terms contained * in the LICENSE file. */ /* RFC2136 DNS inform - necessary for Win2k3 DNS servers */#include <u.h>#include <libc.h>#include <bio.h>#include <ndb.h>#include <ip.h>#include "dns.h" enum {	FQDNMAX	= 255,}; char *errmsgs[] = {	[0]  "ok",	[1]  "request format error",	[2]  "internal server error",	[3]  "domain name does not exist",	[4]  "request not supported",	[5]  "permission denied",	[6]  "domain name already exists",	[7]  "resource record already exists",	[8]  "resource record does not exist",	[9]  "server not authoritative",	[10] "domain name not in zone",}; voidusage(void){	fprint(2, "usage: %s [-x netmtpt]\n", argv0);	exits("usage");} voidding(void *, char *msg){	if(strstr(msg, "alarm") != nil)		noted(NCONT);	noted(NDFLT);} intg16(uchar **p){	int n; 	n  = *(*p)++ << 8;	n |= *(*p)++;	return n;} voidp16(uchar **p, int n){	*(*p)++ = n >> 8;	*(*p)++ = n;} voidp32(uchar **p, int n){	*(*p)++ = n >> 24;	*(*p)++ = n >> 16;	*(*p)++ = n >> 8;	*(*p)++ = n;} voidpmem(uchar **p, void *v, int len){	memmove(*p, v, len);	*p += len;} voidpname(uchar **p, char *s){	uchar *len; 	while (*s){		len = (*p)++;		while(*s && *s != '.')			*(*p)++ = *s++;		*len = *p - len - 1;		if(*s == '.')			s++;	}	*(*p)++ = 0;} voidmain(int argc, char *argv[]){	int debug, len, fd;	uint err;	char *sysname, *dnsdomain, *dom, *inform, *ns, net[32];	uchar *p, buf[4096], addr[IPv4addrlen], v6addr[IPaddrlen];	ushort txid;	Ndb *db;	Ndbtuple *t, *tt;	static char *query[] = { "dom", "dnsdomain", "ns", "inform" }; 	fmtinstall('I', eipfmt);	fmtinstall('V', eipfmt);	setnetmtpt(net, sizeof net, nil); 	debug = 0;	ns = nil;	dom = nil;	inform = nil;	dnsdomain = nil;	ARGBEGIN{	case 'd':		debug = 1;		break;	case 'x':		setnetmtpt(net, sizeof net, EARGF(usage()));		break;	default:		usage();	}ARGEND; 	if(argc != 0)		usage(); 	if((sysname = getenv("sysname")) == nil)		sysfatal("$sysname not set"); 	if((db = ndbopen(nil)) == nil)		sysfatal("can't open ndb: %r");	tt = ndbipinfo(db, "sys", sysname, query, nelem(query));	for(t = tt; t; t = t->entry){		if(strcmp(t->attr, "ns") == 0)			ns = t->val;		else if(strcmp(t->attr, "dom") == 0)			dom = t->val;		else if(strcmp(t->attr, "dnsdomain") == 0)			dnsdomain = t->val;		else if(strcmp(t->attr, "inform") == 0)			inform = t->val;	} 	ndbfree(tt);	ndbclose(db); 	if(inform)		dom = inform;	if(!ns)		sysfatal("no relevant ns=");	if(!dom)		sysfatal("no relevant dom=");	if(!dnsdomain)		sysfatal("no relevant dnsdomain="); 	myipaddr(v6addr, net);	memmove(addr, v6addr + IPaddrlen - IPv4addrlen, IPv4addrlen); 	if(debug){		print("ip=%V\n", addr);		print("ns=%s\n", ns);		print("dnsdomain=%s\n", dnsdomain);		print("dom=%s\n", dom);	} 	if((fd = dial(netmkaddr(ns, "udp", "dns"), 0, 0, 0)) < 0)		sysfatal("can't dial %s: %r", ns); 	txid = time(nil) + getpid(); 	p = buf;	p16(&p, txid);		/* ID */	p16(&p, 5<<11);		/* flags */	p16(&p, 1);		/* # Zones */	p16(&p, 0);		/* # prerequisites */	p16(&p, 2);		/* # updates */	p16(&p, 0);		/* # additionals */         pname(&p, dnsdomain);	/* zone */	p16(&p, Tsoa);		/* zone type */	p16(&p, Cin);		/* zone class */ 	/* delete old name */        pname(&p, dom);		/* name */	p16(&p, Ta);		/* type: v4 addr */	p16(&p, Call);		/* class */	p32(&p, 0);		/* TTL */	p16(&p, 0);		/* data len */ 	/* add new A record */	pname(&p, dom);		/* name */	p16(&p, Ta);		/* type: v4 addr */	p16(&p, Cin);		/* class */	p32(&p, 60*60*25);	/* TTL (25 hours) */	p16(&p, IPv4addrlen);	/* data len */	pmem(&p, addr, IPv4addrlen);	/* v4 address */ 	len = p - buf;	if(write(fd, buf, len) != len)		sysfatal("write failed: %r"); 	notify(ding);	alarm(3000);	do{		if(read(fd, buf, sizeof buf) < 0)			sysfatal("timeout");		p = buf;	}while(g16(&p) != txid);	alarm(0); 	close(fd); 	err = g16(&p) & 7;	if(err != 0 && err != 7)	/* err==7 is just a "yes, I know" warning */		if(err < nelem(errmsgs))			sysfatal("%s", errmsgs[err]);		else			sysfatal("unknown dns server error %d", err);	exits(0);}