smbcomopen.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 "headers.h"

static void
smblogprintattr(int cmd, ushort attr)
{
	if (attr & SMB_ATTR_READ_ONLY)
		smblogprint(cmd, " readonly");
	if (attr & SMB_ATTR_HIDDEN)
		smblogprint(cmd, " hidden");
	if (attr & SMB_ATTR_SYSTEM)
		smblogprint(cmd, " system");
	if (attr & SMB_ATTR_DIRECTORY)
		smblogprint(cmd, " directory");
	if (attr & SMB_ATTR_ARCHIVE)
		smblogprint(cmd, " archive");
}

static SmbFile *
openfile(SmbSession *s, SmbTree *t, char *path, ushort mode, ushort attr, ushort ofun, ulong createoptions, uvlong createsize,
	ushort *fidp, Dir **dp, ushort *actionp)
{
	int p9mode;
	int share;
	Dir *d = nil;
	int fd = -1;
	ushort action;
	SmbFile *f = nil;
	SmbSharedFile *sf = nil;
	char *fullpath = nil;
	int diropen = 0;

	p9mode = (mode >> SMB_OPEN_MODE_ACCESS_SHIFT) & SMB_OPEN_MODE_ACCESS_MASK;	
	share = (mode >> SMB_OPEN_MODE_SHARE_SHIFT) & SMB_OPEN_MODE_SHARE_MASK;	
	if (share == SMB_OPEN_MODE_SHARE_COMPATIBILITY) {
	badshare:
		smbseterror(s, ERRDOS, ERRbadshare);
		goto done;
	}
	smbstringprint(&fullpath, "%s%s", t->serv->path, path);
	d = dirstat(fullpath);
	if (d) {
		/* file exists */
		int ofunexist;
		if (d->mode & DMDIR) {
			if (createoptions & SMB_CO_FILE) {
				smbseterror(s, ERRDOS, ERRnoaccess);
				goto done;
			}
		}
		else if (createoptions & SMB_CO_DIRECTORY) {
			smbseterror(s, ERRDOS, ERRnoaccess);
			goto done;
		}
			
		sf = smbsharedfileget(d, p9mode, &share);
		if (sf == nil)
			goto badshare;
		action = 1;
		ofunexist = (ofun >> SMB_OFUN_EXIST_SHIFT) & SMB_OFUN_EXIST_MASK;
		if (ofunexist == SMB_OFUN_EXIST_FAIL) {
			smbseterror(s, ERRDOS, ERRfilexists);
			goto done;
		}
		else if (ofunexist == SMB_OFUN_EXIST_TRUNCATE) {
			if ((d->mode & DMDIR) || (p9mode != OWRITE && p9mode != ORDWR)) {
				smbseterror(s, ERRDOS, ERRbadaccess);
				goto done;
			}
			p9mode |= OTRUNC;
			action = 3;
		}
		else if (ofunexist != SMB_OFUN_EXIST_OPEN) {
			smbseterror(s, ERRDOS, ERRbadaccess);
			goto done;
		}
		if (d->mode & DMDIR)
			diropen = 1;
		else
			fd = open(fullpath, p9mode);
	}
	else {
		/* file does not exist */
		ulong p9attr;
		action = 3;
		if ((ofun & SMB_OFUN_NOEXIST_CREATE) == 0) {
			smbseterror(s, ERRDOS, ERRbadfile);
			goto done;
		}
		if (createsize != 0) {
			smbseterror(s, ERRDOS, ERRunsup);
			goto done;
		}
//smblogprint(-1, "creating: attr 0x%.4ux co 0x%.8lux\n", attr, createoptions);
		if (createoptions & SMB_CO_FILE) {
			attr &= SMB_ATTR_DIRECTORY;
			if (attr == 0)
				attr = SMB_ATTR_NORMAL;
		}
		else if (createoptions & SMB_CO_DIRECTORY) {
			attr &= ~SMB_ATTR_NORMAL;
			attr |= SMB_ATTR_DIRECTORY;
		}
//smblogprint(-1, "creating: before conversion attr 0x%.4ux\n", attr);
		p9attr = smbdosattr2plan9mode(attr);
//smblogprint(-1, "creating: after conversion p9attr 0%.uo\n", p9attr);
		fd = create(fullpath, p9mode, p9attr);
		if (fd >= 0) {
			d = dirfstat(fd);
			sf = smbsharedfileget(d, p9mode, &share);
			if (sf == nil) {
				close(fd);
				remove(path);
				goto badshare;
			}
		}
	}
	if (!diropen && fd < 0) {
		smbseterror(s, ERRSRV, ERRaccess);
		goto done;
	}
	f = smbemalloc(sizeof(SmbFile));
	if (diropen) {
		f->ioallowed = 0;
		f->fd = -1;
	}
	else {
		f->ioallowed = 1;
		f->fd = fd;
	}
	f->name = smbestrdup(path);
	f->sf = sf;
	sf = nil;
	f->share = share;
	f->p9mode = p9mode;
	f->t = t;
	if (s->fidmap == nil)
		s->fidmap = smbidmapnew();
	*fidp = smbidmapadd(s->fidmap, f);
	smblogprintif(smbglobals.log.fids, "openfile: 0x%.4ux/0x%.4ux %s\n", t->id, *fidp, path);
	if (actionp)
		*actionp = action;
	if (dp) {
		*dp = d;
		d = nil;
	}
done:
	if (sf)
		smbsharedfileput(nil, sf, share);
	free(d);
	free(fullpath);
	return f;
}

SmbProcessResult
smbcomopenandx(SmbSession *s, SmbHeader *h, uchar *pdata, SmbBuffer *b)
{
	uchar andxcommand;
	ushort andxoffset, flags, mode, sattr, attr;
	ulong createtime;	
	ushort ofun;
	ulong createsize, timeout;
	char *path = nil;
	ulong andxoffsetfixupoffset;
	SmbProcessResult pr;
	ushort action;
	Dir *d = nil;
	SmbFile *f;
	SmbTree *t;
	ushort fid;

	if (!smbcheckwordcount("comopenandx", h, 15))
		return SmbProcessResultFormat;

	andxcommand = *pdata++;
	pdata++;
	andxoffset = smbnhgets(pdata); pdata += 2;
	flags = smbnhgets(pdata); pdata += 2;
	mode = smbnhgets(pdata); pdata += 2;
	sattr = smbnhgets(pdata); pdata += 2;
	attr = smbnhgets(pdata); pdata += 2;
	createtime = smbnhgetl(pdata); pdata += 4;
	ofun = smbnhgets(pdata); pdata += 2;
	createsize = smbnhgetl(pdata); pdata += 4;
	timeout = smbnhgetl(pdata); pdata += 4;
	pdata += 4;
	USED(pdata);
	if (!smbbuffergetstring(b, h, SMB_STRING_PATH, &path)) {
		pr = SmbProcessResultFormat;
		goto done;
	}

	smbloglock();
	smblogprint(h->command, "flags 0x%.4ux", flags);
	if (flags & SMB_OPEN_FLAGS_ADDITIONAL)
		smblogprint(h->command, " additional");
	if (flags & SMB_OPEN_FLAGS_OPLOCK)
		smblogprint(h->command, " oplock");
	if (flags & SMB_OPEN_FLAGS_OPBATCH)
		smblogprint(h->command, " opbatch");
	smblogprint(h->command, "\n");
	smblogprint(h->command, "mode 0x%.4ux", mode);
	switch ((mode >> SMB_OPEN_MODE_ACCESS_SHIFT) & SMB_OPEN_MODE_ACCESS_MASK) {
	case OREAD:
		smblogprint(h->command, " OREAD");
		break;
	case OWRITE:
		smblogprint(h->command, " OWRITE");
		break;
	case ORDWR:
		smblogprint(h->command, " ORDWR");
		break;
	case OEXEC:
		smblogprint(h->command, " OEXEC");
		break;
	}
	switch ((mode >> SMB_OPEN_MODE_SHARE_SHIFT) & SMB_OPEN_MODE_SHARE_MASK) {
	case SMB_OPEN_MODE_SHARE_COMPATIBILITY:
		smblogprint(h->command, " compatinility");
		break;
	case SMB_OPEN_MODE_SHARE_EXCLUSIVE:
		smblogprint(h->command, " exclusive");
		break;
	case SMB_OPEN_MODE_SHARE_DENY_WRITE:
		smblogprint(h->command, " deny write");
		break;
	case SMB_OPEN_MODE_SHARE_DENY_READOREXEC:
		smblogprint(h->command, " deny readorxec");
		break;
	case SMB_OPEN_MODE_SHARE_DENY_NONE:
		smblogprint(h->command, " deny none");
		break;
	}
	if (mode & SMB_OPEN_MODE_WRITE_THROUGH)
		smblogprint(h->command, " write through");
	smblogprint(h->command, "\n");
	smblogprint(h->command, "sattr 0x%.4ux", sattr);
	smblogprintattr(h->command, sattr);
	smblogprint(h->command, "\n");
	smblogprint(h->command, "attr 0x%.4ux", attr);
	smblogprintattr(h->command, attr);
	smblogprint(h->command, "\n");
	smblogprint(h->command, "createtime 0x%.8lux\n", createtime);
	smblogprint(h->command, "ofun 0x%.4ux", ofun);
	if (ofun & SMB_OFUN_NOEXIST_CREATE)
		smblogprint(h->command, " noexistscreate");
	else
		smblogprint(h->command, " noexistfail");
	switch ((ofun >> SMB_OFUN_EXIST_SHIFT) & SMB_OFUN_EXIST_MASK) {
	case SMB_OFUN_EXIST_FAIL:
		smblogprint(h->command, " existfail");
		break;
	case SMB_OFUN_EXIST_OPEN:
		smblogprint(h->command, " existopen");
		break;
	case SMB_OFUN_EXIST_TRUNCATE:
		smblogprint(h->command, " existtruncate");
		break;
	}
	smblogprint(h->command, "\n");
	smblogprint(h->command, "createsize 0x%.8lux\n", createsize);
	smblogprint(h->command, "timeout 0x%.8lux\n", timeout);
	smblogprint(h->command, "path %s\n", path);
	smblogunlock();

	t = smbidmapfind(s->tidmap, h->tid);
	if (t == nil) {
		smbseterror(s, ERRSRV, ERRinvtid);
		goto errordone;
	}

	f = openfile(s, t, path, mode, attr, ofun, 0, createsize, &fid, &d, &action);
	if (f == nil) {
		pr = SmbProcessResultError;
		goto done;
	}
	h->wordcount = 15;
	if (!smbbufferputandxheader(s->response, h, &s->peerinfo, andxcommand, &andxoffsetfixupoffset)
		|| !smbbufferputs(s->response, fid)
		|| !smbbufferputs(s->response, smbplan9mode2dosattr(d->mode))
		|| !smbbufferputl(s->response, smbplan9time2utime(d->mtime, s->tzoff))
		|| !smbbufferputl(s->response, smbplan9length2size32(d->length))
		|| !smbbufferputs(s->response, smbplan9mode2dosattr(d->mode)) // probbaly bogus
		|| !smbbufferputs(s->response, 0)	// all files are files
		|| !smbbufferputs(s->response, 0)	// pipe state
		|| !smbbufferputs(s->response, action)
		|| !smbbufferputl(s->response, 0)	// fileID
		|| !smbbufferputs(s->response, 0)
		|| !smbbufferputs(s->response, 0)) {	// bytecount 0
		smbfileclose(s, f);
		pr = SmbProcessResultMisc;
		goto done;
	}
	if (andxcommand != SMB_COM_NO_ANDX_COMMAND)
		pr = smbchaincommand(s, h, andxoffsetfixupoffset, andxcommand, andxoffset, b);
	else
		pr = SmbProcessResultReply;
	goto done;	
errordone:
	pr = SmbProcessResultError;
done:
	free(path);
	free(d);
	return pr;
}

SmbProcessResult
smbcomopen(SmbSession *s, SmbHeader *h, uchar *pdata, SmbBuffer *b)
{
	uchar fmt;