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-rw-r--r--lib/util/xfile.c416
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diff --git a/lib/util/xfile.c b/lib/util/xfile.c
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+++ b/lib/util/xfile.c
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+/*
+ 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"
+
+#if _SAMBA_BUILD_ == 3
+#undef malloc
+#endif
+
+#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 = (XFILE *)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(const 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);
+}
+
+XFILE *x_fdup(const XFILE *f)
+{
+ XFILE *ret;
+ int fd;
+
+ fd = dup(x_fileno(f));
+ if (fd < 0) {
+ return NULL;
+ }
+
+ ret = (XFILE *)malloc_p(XFILE);
+ if (!ret) {
+ close(fd);
+ return NULL;
+ }
+ memset(ret, 0, sizeof(XFILE));
+
+ ret->fd = fd;
+ ret->open_flags = f->open_flags;
+ x_setvbuf(ret, NULL, X_IOFBF, XBUFSIZE);
+ return ret;
+}