tftp: optional tftp-hpa compat

[oweals/busybox.git] / coreutils / cksum.c

diff --git a/coreutils/cksum.c b/coreutils/cksum.c
index 8e65b1ca3b35b84093056c74857cd0eaaade6018..633322bc7eb015bc52e7d44b1021b4cf4365c127 100644 (file)
--- a/coreutils/cksum.c
+++ b/coreutils/cksum.c
@@ -4,19 +4,34 @@
  *
  * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
  *
- * 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.
  */
+//config:config CKSUM
+//config:      bool "cksum (4.1 kb)"
+//config:      default y
+//config:      help
+//config:      cksum is used to calculate the CRC32 checksum of a file.
+
+//applet:IF_CKSUM(APPLET_NOEXEC(cksum, cksum, BB_DIR_USR_BIN, BB_SUID_DROP, cksum))
+/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
+
+//kbuild:lib-$(CONFIG_CKSUM) += cksum.o
+
+//usage:#define cksum_trivial_usage
+//usage:       "FILE..."
+//usage:#define cksum_full_usage "\n\n"
+//usage:       "Calculate the CRC32 checksums of FILEs"
+
 #include "libbb.h"
+#include "common_bufsiz.h"
+
+/* This is a NOEXEC applet. Be very careful! */
 
 int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int cksum_main(int argc UNUSED_PARAM, char **argv)
 {
        uint32_t *crc32_table = crc32_filltable(NULL, 1);
-       uint32_t crc;
-       off_t length, filesize;
-       int bytes_read;
        int exit_code = EXIT_SUCCESS;
-       uint8_t *cp;
 
 #if ENABLE_DESKTOP
        getopt32(argv, ""); /* coreutils 6.9 compat */
@@ -25,42 +40,44 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
        argv++;
 #endif
 
+       setup_common_bufsiz();
        do {
+               uint32_t crc;
+               off_t filesize;
                int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
 
                if (fd < 0) {
                        exit_code = EXIT_FAILURE;
                        continue;
                }
-               crc = 0;
-               length = 0;
 
+               crc = 0;
+               filesize = 0;
 #define read_buf bb_common_bufsiz1
-               while ((bytes_read = safe_read(fd, read_buf, sizeof(read_buf))) > 0) {
-                       cp = (uint8_t *) read_buf;
-                       length += bytes_read;
-                       do {
-                               crc = (crc << 8) ^ crc32_table[(crc >> 24) ^ *cp++];
-                       } while (--bytes_read);
+               for (;;) {
+                       uoff_t t;
+                       int bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE);
+                       if (bytes_read > 0) {
+                               filesize += bytes_read;
+                       } else {
+                               /* Checksum filesize bytes, LSB first, and exit */
+                               close(fd);
+                               fd = -1; /* break flag */
+                               t = filesize;
+                               bytes_read = 0;
+                               while (t != 0) {
+                                       read_buf[bytes_read++] = (uint8_t)t;
+                                       t >>= 8;
+                               }
+                       }
+                       crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table);
+                       if (fd < 0)
+                               break;
                }
-               close(fd);
-
-               filesize = length;
 
-               while (length) {
-                       crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
-                       /* must ensure that shift is unsigned! */
-                       if (sizeof(length) <= sizeof(unsigned))
-                               length = (unsigned)length >> 8;
-                       else if (sizeof(length) <= sizeof(unsigned long))
-                               length = (unsigned long)length >> 8;
-                       else
-                               length = (unsigned long long)length >> 8;
-               }
                crc = ~crc;
-
-               printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"),
-                               crc, filesize, *argv);
+               printf((*argv ? "%u %"OFF_FMT"u %s\n" : "%u %"OFF_FMT"u\n"),
+                               (unsigned)crc, filesize, *argv);
        } while (*argv && *++argv);
 
        fflush_stdout_and_exit(exit_code);