/*
* Utility routines.
*
- * Copyright (C) 1999-200
3 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 1999-200
5 by Erik Andersen <andersen@codepoet.org>
*
- * 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 2 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, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
+#include "libbb.h"
+#if ENABLE_FEATURE_USE_SENDFILE
+# include <sys/sendfile.h>
+#else
+# define sendfile(a,b,c,d) (-1)
+#endif
-#include <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
-#include "busybox.h"
-
+/*
+ * We were using 0x7fff0000 as sendfile chunk size, but it
+ * was seen to cause largish delays when user tries to ^C a file copy.
+ * Let's use a saner size.
+ * Note: needs to be >= max(CONFIG_FEATURE_COPYBUF_KB),
+ * or else "copy to eof" code will use needlesly short reads.
+ */
+#define SENDFILE_BIGBUF (16*1024*1024)
-#if BUFSIZ < 4096
-#undef BUFSIZ
-#define BUFSIZ 4096
+/* 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;
+ bool continue_on_write_error = 0;
+ ssize_t sendfile_sz;
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ char *buffer = buffer; /* for compiler */
+ int buffer_size = 0;
+#else
+ char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
+ enum { buffer_size = sizeof(buffer) };
#endif
+ if (size < 0) {
+ size = -size;
+ continue_on_write_error = 1;
+ }
-/* If size is 0 copy until EOF */
-static size_t bb_full_fd_action(int src_fd, int dst_fd, const size_t size)
-{
- size_t read_total = 0;
- RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
+ if (src_fd < 0)
+ goto out;
- while ((size == 0) || (read_total < size)) {
- size_t read_try;
- ssize_t read_actual;
+ sendfile_sz = !ENABLE_FEATURE_USE_SENDFILE
+ ? 0
+ : SENDFILE_BIGBUF;
+ if (!size) {
+ size = SENDFILE_BIGBUF;
+ status = 1; /* copy until eof */
+ }
- if ((size == 0) || (size - read_total > BUFSIZ)) {
- read_try = BUFSIZ;
- } else {
- read_try = size - read_total;
- }
+ while (1) {
+ ssize_t rd;
- read_actual = safe_read(src_fd, buffer, read_try);
- if ((read_actual > 0) && (dst_fd >= 0)) {
- if (bb_full_write(dst_fd, buffer, (size_t) read_actual) != read_actual) {
- bb_perror_msg(bb_msg_write_error); /* match Read error below */
- break;
+ if (sendfile_sz) {
+ /* dst_fd == -1 is a fake, else... */
+ if (dst_fd >= 0) {
+ rd = sendfile(dst_fd, src_fd, NULL,
+ size > sendfile_sz ? sendfile_sz : size);
+ if (rd >= 0)
+ goto read_ok;
}
+ sendfile_sz = 0; /* do not try sendfile anymore */
}
- else if (read_actual == 0) {
- if (size) {
- bb_error_msg("Unable to read all data");
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (buffer_size == 0) {
+ 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
+ rd = safe_read(src_fd, buffer,
+ size > buffer_size ? buffer_size : size);
+ if (rd < 0) {
+ bb_simple_perror_msg(bb_msg_read_error);
break;
- } else {
- /* read_actual < 0 */
- bb_perror_msg("Read error");
+ }
+ read_ok:
+ if (!rd) { /* eof - all done */
+ status = 0;
break;
}
-
- read_total += read_actual;
+ /* dst_fd == -1 is a fake, else... */
+ if (dst_fd >= 0 && !sendfile_sz) {
+ ssize_t wr = full_write(dst_fd, buffer, rd);
+ if (wr < rd) {
+ if (!continue_on_write_error) {
+ bb_simple_perror_msg(bb_msg_write_error);
+ break;
+ }
+ dst_fd = -1;
+ }
+ }
+ total += rd;
+ if (status < 0) { /* if we aren't copying till EOF... */
+ size -= rd;
+ if (!size) {
+ /* 'size' bytes copied - all done */
+ status = 0;
+ break;
+ }
+ }
}
+ out:
- RELEASE_CONFIG_BUFFER(buffer);
-
- return(read_total);
+/* some environments don't have munmap(), hide it in #if */
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+ if (buffer_size > 4 * 1024)
+ munmap(buffer, buffer_size);
+#endif
+ return status ? -1 : total;
}
-extern int bb_copyfd_size(int fd1, int fd2, const off_t size)
+#if 0
+void FAST_FUNC complain_copyfd_and_die(off_t sz)
+{
+ if (sz != -1)
+ bb_error_msg_and_die("short read");
+ /* if sz == -1, bb_copyfd_XX already complained */
+ xfunc_die();
+}
+#endif
+
+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 bb_full_fd_action(fd1, fd2, size);
}
- return(0);
+ return 0;
+}
+
+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 >= 0 ? size : -size))
+ return;
+ if (sz != -1)
+ bb_simple_error_msg_and_die("short read");
+ /* if sz == -1, bb_copyfd_XX already complained */
+ xfunc_die();
}
-extern int 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));
+ return bb_full_fd_action(fd1, fd2, 0);
}
projects / oweals / busybox.git / blobdiff