Bump to version 1.22.1

[platform/upstream/busybox.git] / libbb / copyfd.c

diff --git a/libbb/copyfd.c b/libbb/copyfd.c
index 87126eb..eda2747 100644 (file)
--- a/libbb/copyfd.c
+++ b/libbb/copyfd.c
@@ -4,63 +4,113 @@
  *
  * 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 (size < 0) {
+               size = -size;
+               continue_on_write_error = 1;
+       }
 
-       if (src_fd < 0) goto out;
-       while (!size || total < size) {
-               ssize_t wr, rd;
+#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 = buffer_size;
+               status = 1; /* copy until eof */
+       }
 
-               rd = safe_read(src_fd, buffer,
-                               (!size || size - total > BUFSIZ) ? BUFSIZ : size - total);
+       while (1) {
+               ssize_t rd;
 
-               if (rd > 0) {
-                       /* A -1 dst_fd means we need to fake it... */
-                       wr = (dst_fd < 0) ? rd : full_write(dst_fd, buffer, rd);
+               rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size);
+
+               if (!rd) { /* eof - all done */
+                       status = 0;
+                       break;
+               }
+               if (rd < 0) {
+                       bb_perror_msg(bb_msg_read_error);
+                       break;
+               }
+               /* dst_fd == -1 is a fake, else... */
+               if (dst_fd >= 0) {
+                       ssize_t wr = full_write(dst_fd, buffer, rd);
                        if (wr < rd) {
-                               bb_perror_msg(bb_msg_write_error);
+                               if (!continue_on_write_error) {
+                                       bb_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;
                        }
-                       total += wr;
-                       if (total == size) status = 0;
-               } else if (rd < 0) {
-                       bb_perror_msg(bb_msg_read_error);
-                       break;
-               } else if (rd == 0) {
-                       /* All done. */
-                       status = 0;
-                       break;
                }
        }
+ out:
 
-out:
-       RELEASE_CONFIG_BUFFER(buffer);
-
-       return status ? status : total;
+#if CONFIG_FEATURE_COPYBUF_KB > 4
+       if (buffer_size != 4 * 1024)
+               munmap(buffer, buffer_size);
+#endif
+       return status ? -1 : total;
 }
 
 
-off_t bb_copyfd_size(int fd1, int fd2, 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);
@@ -68,7 +118,18 @@ off_t bb_copyfd_size(int fd1, int fd2, off_t size)
        return 0;
 }
 
-off_t bb_copyfd_eof(int fd1, int fd2)
+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_error_msg_and_die("short read");
+       /* if sz == -1, bb_copyfd_XX already complained */
+       xfunc_die();
+}
+
+off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
 {
        return bb_full_fd_action(fd1, fd2, 0);
 }