X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=libbb%2Fcopyfd.c;h=eda2747f991b0253b8fe3596d79035a5c373dff3;hb=b2320370be14811459718b9fe418efed75ea3615;hp=17bf4fbc2e505cad068aa5b3191534c518d7a245;hpb=714701c890b5f03253c5ecdb7367c4258ce78715;p=oweals%2Fbusybox.git

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index 17bf4fbc2..eda2747f9 100644
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -4,40 +4,62 @@
  *
  * 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 <errno.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
-
 #include "libbb.h"
 
-
-#if BUFSIZ < 4096
-#undef BUFSIZ
-#define BUFSIZ 4096
-#endif
-
-
+/* 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 (src_fd < 0) goto out;
+	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;
@@ -51,8 +73,11 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
 		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;
@@ -60,28 +85,32 @@ static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
 			size -= rd;
 			if (!size) {
 				/* 'size' bytes copied - all done */
-				status = 0; 
+				status = 0;
 				break;
 			}
 		}
 	}
  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");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	exit(xfunc_error_retval);
+	xfunc_die();
 }
 #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);
@@ -89,18 +118,18 @@ off_t bb_copyfd_size(int fd1, int fd2, off_t 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");
 	/* if sz == -1, bb_copyfd_XX already complained */
-	exit(xfunc_error_retval);
+	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);
 }