proto.c

来自「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」· C语言 代码 · 共 1,658 行 · 第 1/2 页

int
createdir(Node *node)
{
	if(changedir(node->parent) < 0)
		return -1;
	
	sendrequest("MKD", node->d->name);
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success)
		return -1;
	return 0;
}

/*
 *  change to a remote directory.
 */
int
changedir(Node *node)
{
	Node *to;
	String *cdpath;

	to = node;
	if(to == remdir)
		return 0;

	/* build an absolute path */
	switch(os){
	case Tops:
	case VM:
		switch(node->depth){
		case 0:
			remdir = node;
			return 0;
		case 1:
			cdpath = s_clone(node->remname);
			break;
		default:
			return seterr(nosuchfile);
		}
		break;
	case VMS:
		switch(node->depth){
		case 0:
			remdir = node;
			return 0;
		default:
			cdpath = s_new();
			vmspath(node, cdpath);
		}
		break;
	case MVS:
		if(node->depth == 0)
			cdpath = s_clone(remrootpath);
		else{
			cdpath = s_new();
			mvspath(node, cdpath);
		}
		break;
	default:
		if(node->depth == 0)
			cdpath = s_clone(remrootpath);
		else{
			cdpath = s_new();
			unixpath(node, cdpath);
		}
		break;
	}

	uncachedir(remdir, 0);

	/*
	 *  connect, if we need a password (Incomplete)
	 *  act like it worked (best we can do).
	 */
	sendrequest("CWD", s_to_c(cdpath));
	s_free(cdpath);
	switch(getreply(&ctlin, msg, sizeof(msg), 0)){
	case Success:
	case Incomplete:
		remdir = node;
		return 0;
	default:
		return seterr(nosuchfile);
	}
}

/*
 *  read a remote file
 */
int
readfile1(Node *node)
{
	Biobuf *bp;
	char buf[4*1024];
	long off;
	int n;
	int tries;

	if(changedir(node->parent) < 0)
		return -1;

	for(tries = 0; tries < 4; tries++){
		switch(data(OREAD, &bp, "RETR", s_to_c(node->remname))){
		case Extra:
			break;
		case TempFail:
			continue;
		default:
			return seterr(nosuchfile);
		}
		off = 0;
		while((n = read(Bfildes(bp), buf, sizeof buf)) > 0){
			if(filewrite(node, buf, off, n) != n){
				off = -1;
				break;
			}
			off += n;
		}
		if(off < 0)
			return -1;

		/* make sure a file gets created even for a zero length file */
		if(off == 0)
			filewrite(node, buf, 0, 0);

		close(Bfildes(bp));
		switch(getreply(&ctlin, msg, sizeof(msg), 0)){
		case Success:
			return off;
		case TempFail:
			continue;
		default:
			return seterr(nosuchfile);
		}
	}
	return seterr(nosuchfile);
}

int
readfile(Node *node)
{
	int rv, inimage;

	switch(os){
	case MVS:
	case Plan9:
	case Tops:
	case TSO:
		inimage = 0;
		break;
	default:
		inimage = 1;
		image();
		break;
	}

	rv = readfile1(node);

	if(inimage)
		ascii();
	return rv;
}

/*
 *  write back a file
 */
int
createfile1(Node *node)
{
	Biobuf *bp;
	char buf[4*1024];
	long off;
	int n;

	if(changedir(node->parent) < 0)
		return -1;

	if(data(OWRITE, &bp, "STOR", s_to_c(node->remname)) != Extra)
		return -1;
	for(off = 0; ; off += n){
		n = fileread(node, buf, off, sizeof(buf));
		if(n <= 0)
			break;
		write(Bfildes(bp), buf, n);
	}
	close(Bfildes(bp));
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success)
		return -1;
	return off;
}

int
createfile(Node *node)
{
	int rv;

	switch(os){
	case Plan9:
	case Tops:
		break;
	default:
		image();
		break;
	}
	rv = createfile1(node);
	switch(os){
	case Plan9:
	case Tops:
		break;
	default:
		ascii();
		break;
	}
	return rv;
}

/*
 *  remove a remote file
 */
int
removefile(Node *node)
{
	if(changedir(node->parent) < 0)
		return -1;
	
	sendrequest("DELE", s_to_c(node->remname));
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success)
		return -1;
	return 0;
}

/*
 *  remove a remote directory
 */
int
removedir(Node *node)
{
	if(changedir(node->parent) < 0)
		return -1;
	
	sendrequest("RMD", s_to_c(node->remname));
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success)
		return -1;
	return 0;
}

/*
 *  tell remote that we're exiting and then do it
 */
void
quit(void)
{
	sendrequest("QUIT", nil);
	getreply(&ctlin, msg, sizeof(msg), 0);
	exits(0);
}

/*
 *  send a request
 */
static void
sendrequest(char *a, char *b)
{
	char buf[2*1024];
	int n;

	n = strlen(a)+2+1;
	if(b != nil)
		n += strlen(b)+1;
	if(n >= sizeof(buf))
		fatal("proto request too long");
	strcpy(buf, a);
	if(b != nil){
		strcat(buf, " ");
		strcat(buf, b);
	}
	strcat(buf, "\r\n");
	n = strlen(buf);
	if(write(ctlfd, buf, n) != n)
		fatal("remote side hung up");
	if(debug)
		write(2, buf, n);
	lastsend = time(0);
}

/*
 *  replies codes are in the range [100, 999] and may contain multiple lines of
 *  continuation.
 */
static int
getreply(Biobuf *bp, char *msg, int len, int printreply)
{
	char *line;
	char *p;
	int rv;
	int i, n;

	while(line = Brdline(bp, '\n')){
		/* add line to message buffer, strip off \r */
		n = Blinelen(bp);
		if(n > 1 && line[n-2] == '\r'){
			n--;
			line[n-1] = '\n';
		}
		if(printreply && !quiet)
			write(1, line, n);
		else if(debug)
			write(2, line, n);
		if(n > len - 1)
			i = len - 1;
		else
			i = n;
		if(i > 0){
			memmove(msg, line, i);
			msg += i;
			len -= i;
			*msg = 0;
		}

		/* stop if not a continuation */
		rv = strtol(line, &p, 10);
		if(rv >= 100 && rv < 600 && p==line+3 && *p != '-')
			return rv/100;

		/* tell user about continuations */
		if(!debug && !quiet && !printreply)
			write(2, line, n);
	}

	fatal("remote side closed connection");
	return 0;
}

/*
 *  Announce on a local port and tell its address to the the remote side
 */
static int
port(void)
{
	char buf[256];
	int n, fd;
	char *ptr;
	uchar ipaddr[IPaddrlen];
	int port;

	/* get a channel to listen on, let kernel pick the port number */
	sprint(buf, "%s!*!0", net);
	listenfd = announce(buf, netdir);
	if(listenfd < 0)
		return seterr("can't announce");

	/* get the local address and port number */
	sprint(buf, "%s/local", netdir);
	fd = open(buf, OREAD);
	if(fd < 0)
		return seterr("opening %s: %r", buf);
	n = read(fd, buf, sizeof(buf)-1);
	close(fd);
	if(n <= 0)
		return seterr("opening %s/local: %r", netdir);
	buf[n] = 0;
	ptr = strchr(buf, ' ');
	if(ptr)
		*ptr = 0;
	ptr = strchr(buf, '!')+1;
	port = atoi(ptr);

	memset(ipaddr, 0, IPaddrlen);
	if (*net){
		strcpy(buf, net);
		ptr = strchr(buf +1, '/');
		if (ptr)
			*ptr = 0;
		myipaddr(ipaddr, buf);
	}

	/* tell remote side */
	sprint(buf, "PORT %d,%d,%d,%d,%d,%d", ipaddr[IPv4off+0], ipaddr[IPv4off+1],
		ipaddr[IPv4off+2], ipaddr[IPv4off+3], port>>8, port&0xff);
	sendrequest(buf, nil);
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success)
		return seterr(msg);
	return 0;
}

/*
 *  have server call back for a data connection
 */
static int
active(int mode, Biobuf **bpp, char *cmda, char *cmdb)
{
	int cfd, dfd, rv;
	char newdir[Maxpath];
	char datafile[Maxpath + 6];
	TLSconn conn;

	if(port() < 0)
		return TempFail;

	sendrequest(cmda, cmdb);

	rv = getreply(&ctlin, msg, sizeof(msg), 0);
	if(rv != Extra){
		close(listenfd);
		return rv;
	}

	/* wait for a new call */
	cfd = listen(netdir, newdir);
	if(cfd < 0)
		fatal("waiting for data connection");
	close(listenfd);

	/* open it's data connection and close the control connection */
	sprint(datafile, "%s/data", newdir);
	dfd = open(datafile, ORDWR);
	close(cfd);
	if(dfd < 0)
		fatal("opening data connection");

	if(usetls){
		memset(&conn, 0, sizeof(conn));
		dfd = tlsClient(dfd, &conn);
		if(dfd < 0)
			fatal("starting tls: %r");
		free(conn.cert);
	}

	Binit(&dbuf, dfd, mode);
	*bpp = &dbuf;
	return Extra;
}

/*
 *  call out for a data connection
 */
static int
passive(int mode, Biobuf **bpp, char *cmda, char *cmdb)
{
	char msg[1024];
	char ds[1024];
	char *f[6];
	char *p;
	int x, fd;
	TLSconn conn;

	if(nopassive)
		return Impossible;

	sendrequest("PASV", nil);
	if(getreply(&ctlin, msg, sizeof(msg), 0) != Success){
		nopassive = 1;
		return Impossible;
	}

	/* get address and port number from reply, this is AI */
	p = strchr(msg, '(');
	if(p == 0){
		for(p = msg+3; *p; p++)
			if(isdigit(*p))
				break;
	} else
		p++;
	if(getfields(p, f, 6, 0, ",") < 6){
		if(debug)
			fprint(2, "passive mode protocol botch: %s\n", msg);
		werrstr("ftp protocol botch");
		nopassive = 1;
		return Impossible;
	}
	snprint(ds, sizeof(ds), "%s!%s.%s.%s.%s!%d", net,
		f[0], f[1], f[2], f[3],
		((atoi(f[4])&0xff)<<8) + (atoi(f[5])&0xff));

	/* open data connection */
	fd = dial(ds, 0, 0, 0);
	if(fd < 0){
		if(debug)
			fprint(2, "passive mode connect to %s failed: %r\n", ds);
		nopassive = 1;
		return TempFail;
	}

	/* tell remote to send a file */
	sendrequest(cmda, cmdb);
	x = getreply(&ctlin, msg, sizeof(msg), 0);
	if(x != Extra){
		close(fd);
		if(debug)
			fprint(2, "passive mode retrieve failed: %s\n", msg);
		werrstr(msg);
		return x;
	}

	if(usetls){
		memset(&conn, 0, sizeof(conn));
		fd = tlsClient(fd, &conn);
		if(fd < 0)
			fatal("starting tls: %r");
		free(conn.cert);
	}
	Binit(&dbuf, fd, mode);

	*bpp = &dbuf;
	return Extra;
}

static int
data(int mode, Biobuf **bpp, char* cmda, char *cmdb)
{
	int x;

	x = passive(mode, bpp, cmda, cmdb);
	if(x != Impossible)
		return x;
	return active(mode, bpp, cmda, cmdb);
}

/*
 *  used for keep alives
 */
void
nop(void)
{
	if(lastsend - time(0) < 15)
		return;
	sendrequest("PWD", nil);
	getreply(&ctlin, msg, sizeof(msg), 0);
}

/*
 *  turn a vms spec into a path
 */
static Node*
vmsextendpath(Node *np, char *name)
{
	np = extendpath(np, s_copy(name));
	if(!ISVALID(np)){
		np->d->qid.type = QTDIR;
		np->d->atime = time(0);
		np->d->mtime = np->d->atime;
		strcpy(np->d->uid, "who");
		strcpy(np->d->gid, "cares");
		np->d->mode = DMDIR|0777;
		np->d->length = 0;
		if(changedir(np) >= 0)
			VALID(np);
	}
	return np;
}
static Node*
vmsdir(char *name)
{
	char *cp;
	Node *np;
	char *oname;

	np = remroot;
	cp = strchr(name, '[');
	if(cp)
		strcpy(cp, cp+1);
	cp = strchr(name, ']');
	if(cp)
		*cp = 0;
	oname = name = strdup(name);
	if(name == 0)
		return 0;

	while(cp = strchr(name, '.')){
		*cp = 0;
		np = vmsextendpath(np, name);
		name = cp+1;
	}
	np = vmsextendpath(np, name);

	/*
	 *  walk back to first accessible directory
	 */
	for(; np->parent != np; np = np->parent)
		if(ISVALID(np)){
			CACHED(np->parent);
			break;
		}

	free(oname);
	return np;
}

/*
 *  walk up the tree building a VMS style path
 */
static void
vmspath(Node *node, String *path)
{
	char *p;
	int n;

	if(node->depth == 1){
		p = strchr(s_to_c(node->remname), ':');
		if(p){
			n = p - s_to_c(node->remname) + 1;
			s_nappend(path, s_to_c(node->remname), n);
			s_append(path, "[");
			s_append(path, p+1);
		} else {
			s_append(path, "[");
			s_append(path, s_to_c(node->remname));
		}
		s_append(path, "]");
		return;
	}
	vmspath(node->parent, path);
	s_append(path, ".");
	s_append(path, s_to_c(node->remname));
}

/*
 *  walk up the tree building a Unix style path
 */
static void
unixpath(Node *node, String *path)
{
	if(node == node->parent){
		s_append(path, s_to_c(remrootpath));
		return;
	}
	unixpath(node->parent, path);
	if(s_len(path) > 0 && strcmp(s_to_c(path), "/") != 0)
		s_append(path, "/");
	s_append(path, s_to_c(node->remname));
}

/*
 *  walk up the tree building a MVS style path
 */
static void
mvspath(Node *node, String *path)
{
	if(node == node->parent){
		s_append(path, s_to_c(remrootpath));
		return;
	}
	mvspath(node->parent, path);
	if(s_len(path) > 0)
		s_append(path, ".");
	s_append(path, s_to_c(node->remname));
}

static int
getpassword(char *buf, char *e)
{
	char *p;
	int c;
	int consctl, rv = 0;

	consctl = open("/dev/consctl", OWRITE);
	if(consctl >= 0)
		write(consctl, "rawon", 5);
	print("Password: ");
	e--;
	for(p = buf; p <= e; p++){
		c = Bgetc(&stdin);
		if(c < 0){
			rv = -1;
			goto out;
		}
		if(c == '\n' || c == '\r')
			break;
		*p = c;
	}
	*p = 0;
	print("\n");

out:
	if(consctl >= 0)
		close(consctl);
	return rv;
}

/*
 *  convert from latin1 to utf
 */
static char*
fromlatin1(char *from)
{
	char *p, *to;
	Rune r;

	if(os == Plan9)
		return nil;

	/* don't convert if we don't have to */
	for(p = from; *p; p++)
		if(*p & 0x80)
			break;
	if(*p == 0)
		return nil;

	to = malloc(3*strlen(from)+2);
	if(to == nil)
		return nil;
	for(p = to; *from; from++){
		r = (*from) & 0xff;
		p += runetochar(p, &r);
	}
	*p = 0;
	return to;
}

Dir*
reallocdir(Dir *d, int dofree)
{
	Dir *dp;
	char *p;
	int nn, ng, nu, nm;
	char *utf;

	if(d->name == nil)
		d->name = "?name?";
	if(d->uid == nil)
		d->uid = "?uid?";
	if(d->gid == nil)
		d->gid = d->uid;
	if(d->muid == nil)
		d->muid = d->uid;
	
	utf = fromlatin1(d->name);
	if(utf != nil)
		d->name = utf;

	nn = strlen(d->name)+1;
	nu = strlen(d->uid)+1;
	ng = strlen(d->gid)+1;
	nm = strlen(d->muid)+1;
	dp = malloc(sizeof(Dir)+nn+nu+ng+nm);
	if(dp == nil){
		if(dofree)
			free(d);
		if(utf != nil)
			free(utf);
		return nil;
	}
	*dp = *d;
	p = (char*)&dp[1];
	strcpy(p, d->name);
	dp->name = p;
	p += nn;
	strcpy(p, d->uid);
	dp->uid = p;
	p += nu;
	strcpy(p, d->gid);
	dp->gid = p;
	p += ng;
	strcpy(p, d->muid);
	dp->muid = p;
	if(dofree)
		free(d);
	if(utf != nil)
		free(utf);
	return dp;
}

Dir*
dir_change_name(Dir *d, char *name)
{
	if(d->name && strlen(d->name) >= strlen(name)){
		strcpy(d->name, name);
		return d;
	}
	d->name = name;
	return reallocdir(d, 1);
}

Dir*
dir_change_uid(Dir *d, char *name)
{
	if(d->uid && strlen(d->uid) >= strlen(name)){
		strcpy(d->name, name);
		return d;
	}
	d->uid = name;
	return reallocdir(d, 1);
}

Dir*
dir_change_gid(Dir *d, char *name)
{
	if(d->gid && strlen(d->gid) >= strlen(name)){
		strcpy(d->name, name);
		return d;
	}
	d->gid = name;
	return reallocdir(d, 1);
}

Dir*
dir_change_muid(Dir *d, char *name)
{
	if(d->muid && strlen(d->muid) >= strlen(name)){
		strcpy(d->name, name);
		return d;
	}
	d->muid = name;
	return reallocdir(d, 1);
}

static int
nw_mode(char dirlet, char *s)		/* NetWare file mode mapping */
{
	int mode = 0777;

	if(dirlet == 'd')
		mode |= DMDIR;

	if (strlen(s) >= 10 && s[0] != '[' || s[9] != ']')
		return(mode);

	if (s[1] == '-')					/* can't read file */
		mode &= ~0444;
	if (dirlet == 'd' && s[6] == '-')			/* cannot scan dir */
		mode &= ~0444;
	if (s[2] == '-')					/* can't write file */
		mode &= ~0222;
	if (dirlet == 'd' && s[7] == '-' && s[3] == '-')	/* cannot create in, or modify dir */
		mode &= ~0222;

	return(mode);
}