*
* Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
*
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
-#if BUFSIZ < 4096
-#undef BUFSIZ
-#define BUFSIZ 4096
-#endif
-
-/* Used by NOFORK applets (e.g. cat) - must be very careful
- * when calling xfuncs, allocating memory, with signals, termios, etc... */
-
+/* Used by NOFORK applets (e.g. cat) - must not use xmalloc.
+ * size < 0 means "ignore write errors", used by tar --to-command
+ * size = 0 means "copy till EOF"
+ */
static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
{
int status = -1;
off_t total = 0;
- RESERVE_CONFIG_BUFFER(buffer, BUFSIZ);
+ bool continue_on_write_error = 0;
+#if CONFIG_FEATURE_COPYBUF_KB <= 4
+ char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
+ enum { buffer_size = sizeof(buffer) };
+#else
+ char *buffer;
+ int buffer_size;
+#endif
+
+ if (size < 0) {
+ size = -size;
+ continue_on_write_error = 1;
+ }
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (size > 0 && size <= 4 * 1024)
+ goto use_small_buf;
+ /* We want page-aligned buffer, just in case kernel is clever
+ * and can do page-aligned io more efficiently */
+ buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
+ PROT_READ | PROT_WRITE,
+ MAP_PRIVATE | MAP_ANON,
+ /* ignored: */ -1, 0);
+ buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
+ if (buffer == MAP_FAILED) {
+ use_small_buf:
+ buffer = alloca(4 * 1024);
+ buffer_size = 4 * 1024;
+ }
+#endif
if (src_fd < 0)
goto out;
if (!size) {
- size = BUFSIZ;
+ size = buffer_size;
status = 1; /* copy until eof */
}
while (1) {
ssize_t rd;
- rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size);
+ rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size);
if (!rd) { /* eof - all done */
status = 0;
if (dst_fd >= 0) {
ssize_t wr = full_write(dst_fd, buffer, rd);
if (wr < rd) {
- bb_perror_msg(bb_msg_write_error);
- break;
+ if (!continue_on_write_error) {
+ bb_perror_msg(bb_msg_write_error);
+ break;
+ }
+ dst_fd = -1;
}
}
total += rd;
}
}
out:
- RELEASE_CONFIG_BUFFER(buffer);
+
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (buffer_size != 4 * 1024)
+ munmap(buffer, buffer_size);
+#endif
return status ? -1 : total;
}
#if 0
-void complain_copyfd_and_die(off_t sz)
+void FAST_FUNC complain_copyfd_and_die(off_t sz)
{
if (sz != -1)
bb_error_msg_and_die("short read");
}
#endif
-off_t bb_copyfd_size(int fd1, int fd2, off_t size)
+off_t FAST_FUNC bb_copyfd_size(int fd1, int fd2, off_t size)
{
if (size) {
return bb_full_fd_action(fd1, fd2, size);
return 0;
}
-void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
+void FAST_FUNC bb_copyfd_exact_size(int fd1, int fd2, off_t size)
{
off_t sz = bb_copyfd_size(fd1, fd2, size);
- if (sz == size)
+ if (sz == (size >= 0 ? size : -size))
return;
if (sz != -1)
bb_error_msg_and_die("short read");
xfunc_die();
}
-off_t bb_copyfd_eof(int fd1, int fd2)
+off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
{
return bb_full_fd_action(fd1, fd2, 0);
}