config.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include	"all.h"
#include	"io.h"

static void	dowormcopy(void);
static int	dodevcopy(void);

/*
 * This is needed for IP configuration.
 */
#include	"../ip/ip.h"

struct
{
	char*	icharp;
	char*	charp;
	int	error;
	int	newconf;	/* clear befor start */
	int	modconf;	/* write back when done */
	int	nextiter;
	int	lastiter;
	int	diriter;
	int	ipauthset;
	Device*	lastcw;
	Device*	devlist;
} f;

static Device* confdev;
static int copyworm = 0, copydev = 0;
static char *src, *dest;

int
devcmpr(Device *d1, Device *d2)
{
	while (d1 != d2) {
		if(d1 == 0 || d2 == 0 || d1->type != d2->type)
			return 1;

		switch(d1->type) {
		default:
			print("can't compare dev: %Z\n", d1);
			panic("devcmp");
			return 1;

		case Devmcat:
		case Devmlev:
		case Devmirr:
			d1 = d1->cat.first;
			d2 = d2->cat.first;
			while(d1 && d2) {
				if(devcmpr(d1, d2))
					return 1;
				d1 = d1->link;
				d2 = d2->link;
			}
			break;

		case Devnone:
			return 0;

		case Devro:
			d1 = d1->ro.parent;
			d2 = d2->ro.parent;
			break;

		case Devjuke:
		case Devcw:
			if(devcmpr(d1->cw.c, d2->cw.c))
				return 1;
			d1 = d1->cw.w;
			d2 = d2->cw.w;
			break;

		case Devfworm:
			d1 = d1->fw.fw;
			d2 = d2->fw.fw;
			break;

		case Devwren:
		case Devworm:
		case Devlworm:
		case Devide:
		case Devmarvsata:
			if(d1->wren.ctrl == d2->wren.ctrl)
			if(d1->wren.targ == d2->wren.targ)
			if(d1->wren.lun == d2->wren.lun)
				return 0;
			return 1;

		case Devpart:
			if(d1->part.base == d2->part.base)
			if(d1->part.size == d2->part.size) {
				d1 = d1->part.d;
				d2 = d2->part.d;
				break;
			}
			return 1;
		}
	}
	return 0;
}

void
cdiag(char *s, int c1)
{

	f.charp--;
	if(f.error == 0) {
		print("config diag: %s -- <%c>\n", s, c1);
		f.error = 1;
	}
}

int
cnumb(void)
{
	int c, n;

	c = *f.charp++;
	if(c == '<') {
		n = f.nextiter;
		if(n >= 0) {
			f.nextiter = n+f.diriter;
			if(n == f.lastiter) {
				f.nextiter = -1;
				f.lastiter = -1;
			}
			do {
				c = *f.charp++;
			} while (c != '>');
			return n;
		}
		n = cnumb();
		if(*f.charp++ != '-') {
			cdiag("- expected", f.charp[-1]);
			return 0;
		}
		c = cnumb();
		if(*f.charp++ != '>') {
			cdiag("> expected", f.charp[-1]);
			return 0;
		}
		f.lastiter = c;
		f.diriter = 1;
		if(n > c)
			f.diriter = -1;
		f.nextiter = n+f.diriter;
		return n;
	}
	if(c < '0' || c > '9') {
		cdiag("number expected", c);
		return 0;
	}
	n = 0;
	while(c >= '0' && c <= '9') {
		n = n*10 + (c-'0');
		c = *f.charp++;
	}
	f.charp--;
	return n;
}

Device*
config1(int c)
{
	Device *d, *t;
	int m;

	d = ialloc(sizeof(Device), 0);
	for(;;) {
		t = config();
		if(d->cat.first == 0)
			d->cat.first = t;
		else
			d->cat.last->link = t;
		d->cat.last = t;
		if(f.error)
			return devnone;
		m = *f.charp;
		if(c == '(' && m == ')') {
			d->type = Devmcat;
			break;
		}
		if(c == '[' && m == ']') {
			d->type = Devmlev;
			break;
		}
		if(c == '{' && m == '}') {
			d->type = Devmirr;
			break;
		}
	}
	f.charp++;
	if(d->cat.first == d->cat.last)
		d = d->cat.first;
	return d;
}

Device*
config(void)
{
	int c, m;
	Device *d;
	char *icp;

	if(f.error)
		return devnone;
	d = ialloc(sizeof(Device), 0);

	c = *f.charp++;
	switch(c) {
	default:
		cdiag("unknown type", c);
		return devnone;

	case '(':	/* (d+) one or multiple cat */
	case '[':	/* [d+] one or multiple interleave */
	case '{':	/* {d+} a mirrored device and optional mirrors */
		return config1(c);

	case 'f':	/* fd fake worm */
		d->type = Devfworm;
		d->fw.fw = config();
		break;

	case 'n':
		d->type = Devnone;
		break;

	case 'w':	/* w[#.]#[.#] wren	[ctrl] unit [lun] */
	case 'h':	/* h[#.]# ide		[ctlr] unit */
	case 'm':	/* m[#.]# marvell sata	[ctlr] unit */
	case 'r':	/* r# worm side */
	case 'l':	/* l# labelled-worm side */
		icp = f.charp;
		if(c == 'm')
			d->type = Devmarvsata;
		else if(c == 'h')
			d->type = Devide;
		else
			d->type = Devwren;
		d->wren.ctrl = 0;
		d->wren.targ = cnumb();
		d->wren.lun = 0;
		m = *f.charp;
		if(m == '.') {
			f.charp++;
			d->wren.lun = cnumb();
			m = *f.charp;
			if(m == '.') {
				f.charp++;
				d->wren.ctrl = d->wren.targ;
				d->wren.targ = d->wren.lun;
				d->wren.lun = cnumb();
			}
		}
		if(f.nextiter >= 0)
			f.charp = icp-1;
		if(c == 'r') {	/* worms are virtual and not uniqued */
			d->type = Devworm;
			break;
		}
		if(c == 'l') {
			d->type = Devlworm;
			break;
		}
		break;

	case 'o':	/* o ro part of last cw */
		if(f.lastcw == 0) {
			cdiag("no cw to match", c);
			return devnone;
		}
		return f.lastcw->cw.ro;

	case 'j':	/* DD jukebox */
		d->type = Devjuke;
		d->j.j = config();
		d->j.m = config();
		break;

	case 'c':	/* cache/worm */
		d->type = Devcw;
		d->cw.c = config();
		d->cw.w = config();
		d->cw.ro = ialloc(sizeof(Device), 0);
		d->cw.ro->type = Devro;
		d->cw.ro->ro.parent = d;
		f.lastcw = d;
		break;

	case 'p':	/* pd#.# partition base% size% */
		d->type = Devpart;
		d->part.d = config();
		d->part.base = cnumb();
		c = *f.charp++;
		if(c != '.')
			cdiag("dot expected", c);
		d->part.size = cnumb();
		break;

	case 'x':	/* xD swab a device's metadata */
		d->type = Devswab;
		d->swab.d = config();
		break;
	}
	d->dlink = f.devlist;
	f.devlist = d;
	return d;
}

char*
strdup(char *s)
{
	int n;
	char *s1;

	n = strlen(s);
	s1 = ialloc(n+1, 0);
	strcpy(s1, s);
	return s1;
}

Device*
iconfig(char *s)
{
	Device *d;

	f.nextiter = -1;
	f.lastiter = -1;
	f.error = 0;
	f.icharp = s;
	f.charp = f.icharp;
	d = config();
	if(*f.charp) {
		cdiag("junk on end", *f.charp);
		f.error = 1;
	}
	return d;
}

int
testconfig(char *s)
{

	iconfig(s);
	return f.error;
}

int
astrcmp(char *a, char *b)
{
	int n, c;

	n = strlen(b);
	if(memcmp(a, b, n))
		return 1;
	c = a[n];
	if(c == 0) {
		aindex = 0;
		return 0;
	}
	if(a[n+1])
		return 1;
	if(c >= '0' && c <= '9') {
		aindex = c - '0';
		return 0;
	}
	return 1;
}

void
mergeconf(Iobuf *p)
{
	char word[Maxword+1];
	char *cp;
	Filsys *fs;

	for (cp = p->iobuf; ; cp++) {
		cp = getwd(word, cp);
		if(strcmp(word, "") == 0)
			return;
		else if(strcmp(word, "service") == 0) {
			cp = getwd(word, cp);
			if(service[0] == 0)
				strcpy(service, word);
		} else if(strcmp(word, "ipauth") == 0) {
			cp = getwd(word, cp);
			if(!f.ipauthset)
				if(chartoip(authip, word))
					goto bad;
		} else if(astrcmp(word, "ip") == 0) {
			cp = getwd(word, cp);
			if(!isvalidip(ipaddr[aindex].sysip))
				if(chartoip(ipaddr[aindex].sysip, word))
					goto bad;
		} else if(astrcmp(word, "ipgw") == 0) {
			cp = getwd(word, cp);
			if(!isvalidip(ipaddr[aindex].defgwip))
				if(chartoip(ipaddr[aindex].defgwip, word))
					goto bad;
		} else if(astrcmp(word, "ipsntp") == 0) {
			cp = getwd(word, cp);
			if (!isvalidip(sntpip))
				if (chartoip(sntpip, word))
					goto bad;
		} else if(astrcmp(word, "ipmask") == 0) {
			cp = getwd(word, cp);
			if(!isvalidip(ipaddr[aindex].defmask))
				if(chartoip(ipaddr[aindex].defmask, word))
					goto bad;
		} else if(strcmp(word, "filsys") == 0) {
			cp = getwd(word, cp);
			for(fs=filsys; fs->name; fs++)
				if(strcmp(fs->name, word) == 0) {
					if(fs->flags & FEDIT) {
						cp = getwd(word, cp);
						goto loop;
					}
					break;
				}
			fs->name = strdup(word);
			cp = getwd(word, cp);
			fs->conf = strdup(word);
		} else {
bad:
			putbuf(p);
			panic("unknown word in config block: %s", word);
		}
loop:
		if(*cp != '\n')
			goto bad;
	}
}

void
cmd_printconf(int, char *[])
{
	char *p, *s;
	Iobuf *iob;

	iob = getbuf(confdev, 0, Bread);
	if(iob == nil)
		return;
	if(checktag(iob, Tconfig, 0)){
		putbuf(iob);
		return;
	}

	print("config %s\n", nvrgetconfig());
	s = p = iob->iobuf;
	while(*p != 0 && p < iob->iobuf+BUFSIZE){
		if(*p++ != '\n')
			continue;
		print("%.*s", (int)(p-s), s);
		s = p;
	}
	if(p != s)
		print("%.*s", (int)(p-s), s);
	print("end\n");

	putbuf(iob);
}

extern void floppyhalt(void);

void
sysinit(void)
{
	Filsys *fs;
	int error, i;
	Device *d;
	Iobuf *p;
	char *cp;

	dofilter(u->time+0, C0a, C0b, 1);
	dofilter(u->time+1, C1a, C1b, 1);
	dofilter(u->time+2, C2a, C2b, 1);
	dofilter(cons.work+0, C0a, C0b, 1);
	dofilter(cons.work+1, C1a, C1b, 1);
	dofilter(cons.work+2, C2a, C2b, 1);
	dofilter(cons.rate+0, C0a, C0b, 1000);
	dofilter(cons.rate+1, C1a, C1b, 1000);
	dofilter(cons.rate+2, C2a, C2b, 1000);
	dofilter(cons.bhit+0, C0a, C0b, 1);
	dofilter(cons.bhit+1, C1a, C1b, 1);
	dofilter(cons.bhit+2, C2a, C2b, 1);
	dofilter(cons.bread+0, C0a, C0b, 1);
	dofilter(cons.bread+1, C1a, C1b, 1);
	dofilter(cons.bread+2, C2a, C2b, 1);
	dofilter(cons.brahead+0, C0a, C0b, 1);
	dofilter(cons.brahead+1, C1a, C1b, 1);
	dofilter(cons.brahead+2, C2a, C2b, 1);
	dofilter(cons.binit+0, C0a, C0b, 1);
	dofilter(cons.binit+1, C1a, C1b, 1);
	dofilter(cons.binit+2, C2a, C2b, 1);
	cons.chan = chaninit(Devcon, 1, 0);

start:
	/*
	 * part 1 -- read the config file
	 */
	devnone = iconfig("n");

	cp = nvrgetconfig();
	print("config %s\n", cp);

	confdev = d = iconfig(cp);
	devinit(d);
	if(f.newconf) {
		p = getbuf(d, 0, Bmod);
		memset(p->iobuf, 0, RBUFSIZE);
		settag(p, Tconfig, 0);
	} else
		p = getbuf(d, 0, Bread|Bmod);
	if(!p || checktag(p, Tconfig, 0))
		panic("config io");
	mergeconf(p);
	if(f.modconf) {
		memset(p->iobuf, 0, BUFSIZE);
		p->flags |= Bmod|Bimm;
		if(service[0])
			sprint(strchr(p->iobuf, 0), "service %s\n", service);
		for(fs=filsys; fs->name; fs++)
			if(fs->conf)
				sprint(strchr(p->iobuf, 0),
					"filsys %s %s\n", fs->name, fs->conf);
		sprint(strchr(p->iobuf, 0), "ipauth %I\n", authip);
		sprint(strchr(p->iobuf, 0), "ipsntp %I\n", sntpip);
		for(i=0; i<10; i++) {
			if(isvalidip(ipaddr[i].sysip))
				sprint(strchr(p->iobuf, 0),
					"ip%d %I\n", i, ipaddr[i].sysip);
			if(isvalidip(ipaddr[i].defgwip))
				sprint(strchr(p->iobuf, 0),
					"ipgw%d %I\n", i, ipaddr[i].defgwip);
			if(isvalidip(ipaddr[i].defmask))
				sprint(strchr(p->iobuf, 0),