1 files changed, 389 insertions, 0 deletions
diff --git a/source4/lib/util/xfile.c b/source4/lib/util/xfile.c
new file mode 100644
index 0000000000..a016031a77
--- /dev/null
+++ b/source4/lib/util/xfile.c
@@ -0,0 +1,389 @@
+/* 
+   Unix SMB/CIFS implementation.
+   stdio replacement
+   Copyright (C) Andrew Tridgell 2001
+   
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+   
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+   
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/**
+ * @file
+ * @brief scalable FILE replacement
+ */
+
+/*
+  stdio is very convenient, but on some systems the file descriptor
+  in FILE* is 8 bits, so it fails when more than 255 files are open. 
+
+  XFILE replaces stdio. It is less efficient, but at least it works
+  when you have lots of files open
+
+  The main restriction on XFILE is that it doesn't support seeking,
+  and doesn't support O_RDWR. That keeps the code simple.
+*/
+
+#include "includes.h"
+#include "system/filesys.h"
+
+#define XBUFSIZE BUFSIZ
+
+static XFILE _x_stdin =  { 0, NULL, NULL, XBUFSIZE, 0, O_RDONLY, X_IOFBF, 0 };
+static XFILE _x_stdout = { 1, NULL, NULL, XBUFSIZE, 0, O_WRONLY, X_IOLBF, 0 };
+static XFILE _x_stderr = { 2, NULL, NULL, 0, 0, O_WRONLY, X_IONBF, 0 };
+
+XFILE *x_stdin = &_x_stdin;
+XFILE *x_stdout = &_x_stdout;
+XFILE *x_stderr = &_x_stderr;
+
+#define X_FLAG_EOF 1
+#define X_FLAG_ERROR 2
+#define X_FLAG_EINVAL 3
+
+/** simulate setvbuf() */
+int x_setvbuf(XFILE *f, char *buf, int mode, size_t size)
+{
+	x_fflush(f);
+	if (f->bufused) return -1;
+
+	/* on files being read full buffering is the only option */
+	if ((f->open_flags & O_ACCMODE) == O_RDONLY) {
+		mode = X_IOFBF;
+	}
+
+	/* destroy any earlier buffer */
+	SAFE_FREE(f->buf);
+	f->buf = 0;
+	f->bufsize = 0;
+	f->next = NULL;
+	f->bufused = 0;
+	f->buftype = mode;
+
+	if (f->buftype == X_IONBF) return 0;
+
+	/* if buffering then we need some size */
+	if (size == 0) size = XBUFSIZE;
+
+	f->bufsize = size;
+	f->bufused = 0;
+
+	return 0;
+}
+
+/* allocate the buffer */
+static int x_allocate_buffer(XFILE *f)
+{
+	if (f->buf) return 1;
+	if (f->bufsize == 0) return 0;
+	f->buf = (char *)malloc(f->bufsize);
+	if (!f->buf) return 0;
+	f->next = f->buf;
+	return 1;
+}
+
+
+/** this looks more like open() than fopen(), but that is quite deliberate.
+   I want programmers to *think* about O_EXCL, O_CREAT etc not just
+   get them magically added 
+*/
+XFILE *x_fopen(const char *fname, int flags, mode_t mode)
+{
+	XFILE *ret;
+
+	ret = malloc_p(XFILE);
+	if (!ret) return NULL;
+
+	memset(ret, 0, sizeof(XFILE));
+
+	if ((flags & O_ACCMODE) == O_RDWR) {
+		/* we don't support RDWR in XFILE - use file 
+		   descriptors instead */
+		errno = EINVAL;
+		return NULL;
+	}
+
+	ret->open_flags = flags;
+
+	ret->fd = open(fname, flags, mode);
+	if (ret->fd == -1) {
+		SAFE_FREE(ret);
+		return NULL;
+	}
+
+	x_setvbuf(ret, NULL, X_IOFBF, XBUFSIZE);
+	
+	return ret;
+}
+
+/** simulate fclose() */
+int x_fclose(XFILE *f)
+{
+	int ret;
+
+	/* make sure we flush any buffered data */
+	x_fflush(f);
+
+	ret = close(f->fd);
+	f->fd = -1;
+	if (f->buf) {
+		/* make sure data can't leak into a later malloc */
+		memset(f->buf, 0, f->bufsize);
+		SAFE_FREE(f->buf);
+	}
+	/* check the file descriptor given to the function is NOT one of the static
+	 * descriptor of this libreary or we will free unallocated memory
+	 * --sss */
+	if (f != x_stdin && f != x_stdout && f != x_stderr) {
+		SAFE_FREE(f);
+	}
+	return ret;
+}
+
+/** simulate fwrite() */
+size_t x_fwrite(const void *p, size_t size, size_t nmemb, XFILE *f)
+{
+	ssize_t ret;
+	size_t total=0;
+
+	/* we might be writing unbuffered */
+	if (f->buftype == X_IONBF || 
+	    (!f->buf && !x_allocate_buffer(f))) {
+		ret = write(f->fd, p, size*nmemb);
+		if (ret == -1) return -1;
+		return ret/size;
+	} 
+
+
+	while (total < size*nmemb) {
+		size_t n = f->bufsize - f->bufused;
+		n = MIN(n, (size*nmemb)-total);
+
+		if (n == 0) {
+			/* it's full, flush it */
+			x_fflush(f);
+			continue;
+		}
+
+		memcpy(f->buf + f->bufused, total+(const char *)p, n);
+		f->bufused += n;
+		total += n;
+	}
+
+	/* when line buffered we need to flush at the last linefeed. This can
+	   flush a bit more than necessary, but that is harmless */
+	if (f->buftype == X_IOLBF && f->bufused) {
+		int i;
+		for (i=(size*nmemb)-1; i>=0; i--) {
+			if (*(i+(const char *)p) == '\n') {
+				x_fflush(f);
+				break;
+			}
+		}
+	}
+
+	return total/size;
+}
+
+/** thank goodness for asprintf() */
+ int x_vfprintf(XFILE *f, const char *format, va_list ap)
+{
+	char *p;
+	int len, ret;
+	va_list ap2;
+
+	va_copy(ap2, ap);
+	len = vasprintf(&p, format, ap2);
+	va_end(ap2);
+	if (len <= 0) return len;
+	ret = x_fwrite(p, 1, len, f);
+	SAFE_FREE(p);
+	return ret;
+}
+
+ int x_fprintf(XFILE *f, const char *format, ...)
+{
+	va_list ap;
+	int ret;
+
+	va_start(ap, format);
+	ret = x_vfprintf(f, format, ap);
+	va_end(ap);
+	return ret;
+}
+
+/* at least fileno() is simple! */
+int x_fileno(XFILE *f)
+{
+	return f->fd;
+}
+
+/** simulate fflush() */
+int x_fflush(XFILE *f)
+{
+	int ret;
+
+	if (f->flags & X_FLAG_ERROR) return -1;
+
+	if ((f->open_flags & O_ACCMODE) != O_WRONLY) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	if (f->bufused == 0) return 0;
+
+	ret = write(f->fd, f->buf, f->bufused);
+	if (ret == -1) return -1;
+	
+	f->bufused -= ret;
+	if (f->bufused > 0) {
+		f->flags |= X_FLAG_ERROR;
+		memmove(f->buf, ret + (char *)f->buf, f->bufused);
+		return -1;
+	}
+
+	return 0;
+}
+
+/** simulate setbuffer() */
+void x_setbuffer(XFILE *f, char *buf, size_t size)
+{
+	x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, size);
+}
+
+/** simulate setbuf() */
+void x_setbuf(XFILE *f, char *buf)
+{
+	x_setvbuf(f, buf, buf?X_IOFBF:X_IONBF, XBUFSIZE);
+}
+
+/** simulate setlinebuf() */
+void x_setlinebuf(XFILE *f)
+{
+	x_setvbuf(f, NULL, X_IOLBF, 0);
+}
+
+
+/** simulate feof() */
+int x_feof(XFILE *f)
+{
+	if (f->flags & X_FLAG_EOF) return 1;
+	return 0;
+}
+
+/** simulate ferror() */
+int x_ferror(XFILE *f)
+{
+	if (f->flags & X_FLAG_ERROR) return 1;
+	return 0;
+}
+
+/* fill the read buffer */
+static void x_fillbuf(XFILE *f)
+{
+	int n;
+
+	if (f->bufused) return;
+
+	if (!f->buf && !x_allocate_buffer(f)) return;
+
+	n = read(f->fd, f->buf, f->bufsize);
+	if (n <= 0) return;
+	f->bufused = n;
+	f->next = f->buf;
+}
+
+/** simulate fgetc() */
+int x_fgetc(XFILE *f)
+{
+	int ret;
+
+	if (f->flags & (X_FLAG_EOF | X_FLAG_ERROR)) return EOF;
+	
+	if (f->bufused == 0) x_fillbuf(f);
+
+	if (f->bufused == 0) {
+		f->flags |= X_FLAG_EOF;
+		return EOF;
+	}
+
+	ret = *(uint8_t *)(f->next);
+	f->next++;
+	f->bufused--;
+	return ret;
+}
+
+/** simulate fread */
+size_t x_fread(void *p, size_t size, size_t nmemb, XFILE *f)
+{
+	size_t total = 0;
+	while (total < size*nmemb) {
+		int c = x_fgetc(f);
+		if (c == EOF) break;
+		(total+(char *)p)[0] = (char)c;
+		total++;
+	}
+	return total/size;
+}
+
+/** simulate fgets() */
+char *x_fgets(char *s, int size, XFILE *stream) 
+{
+	char *s0 = s;
+	int l = size;
+	while (l>1) {
+		int c = x_fgetc(stream);
+		if (c == EOF) break;
+		*s++ = (char)c;
+		l--;
+		if (c == '\n') break;
+	}
+	if (l==size || x_ferror(stream)) {
+		return 0;
+	}
+	*s = 0;
+	return s0;
+}
+
+/** 
+ * trivial seek, works only for SEEK_SET and SEEK_END if SEEK_CUR is
+ * set then an error is returned */
+off_t x_tseek(XFILE *f, off_t offset, int whence)
+{
+	if (f->flags & X_FLAG_ERROR)
+		return -1;
+
+	/* only SEEK_SET and SEEK_END are supported */
+	/* SEEK_CUR needs internal offset counter */
+	if (whence != SEEK_SET && whence != SEEK_END) {
+		f->flags |= X_FLAG_EINVAL;
+		errno = EINVAL;
+		return -1;
+	}
+
+	/* empty the buffer */
+	switch (f->open_flags & O_ACCMODE) {
+	case O_RDONLY:
+		f->bufused = 0;
+		break;
+	case O_WRONLY:
+		if (x_fflush(f) != 0)
+			return -1;
+		break;
+	default:
+		errno = EINVAL;
+		return -1;
+	}
+
+	f->flags &= ~X_FLAG_EOF;
+	return lseek(f->fd, offset, whence);
+}