#include <u.h>#include <libc.h>#include <bio.h>#include <ndb.h>#include <ndbhf.h> /* *  look up the ip attributes 'list' for an entry that has the *  given 'attr=val' and a 'ip=' tuples. * *  return nil if not found. */Ndbtuple*csipinfo(char *netroot, char *attr, char *val, char **list, int n){	Ndbtuple *t, *first, *last;	int i;	char line[1024];	int fd;	char *p, *e; 	if(netroot)		snprint(line, sizeof(line), "%s/cs", netroot);	else		strcpy(line, "/net/cs");	fd = open(line, ORDWR);	if(fd < 0)		return 0;	seek(fd, 0, 0);	e = line + sizeof(line);	p = seprint(line, e, "!ipinfo %s=%s", attr, val);	for(i = 0; i < n; i++){		if(*list == nil)			break;		p = seprint(p, e, " %s", *list++);	}		if(write(fd, line, strlen(line)) < 0){		close(fd);		return 0;	}	seek(fd, 0, 0); 	first = last = 0;	for(;;){		n = read(fd, line, sizeof(line)-2);		if(n <= 0)			break;		line[n] = '\n';		line[n+1] = 0; 		t = _ndbparseline(line);		if(t == 0)			continue;		if(first)			last->entry = t;		else			first = t;		last = t; 		while(last->entry)			last = last->entry;	}	close(fd); 	ndbsetmalloctag(first, getcallerpc(&netroot));	return first;}