LXR busybox/coreutils/cksum.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * cksum - calculate the CRC32 checksum of a file
   4 *
   5 * Copyright (C) 2006 by Rob Sullivan, with ideas from code by Walter Harms
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8 */
   9//config:config CKSUM
  10//config:       bool "cksum (4.1 kb)"
  11//config:       default y
  12//config:
  13//config:config CRC32
  14//config:       bool "crc32 (4.1 kb)"
  15//config:       default y
  16
  17//                APPLET_NOEXEC:name   main   location        suid_type     help
  18//applet:IF_CKSUM(APPLET_NOEXEC(cksum, cksum, BB_DIR_USR_BIN, BB_SUID_DROP, cksum))
  19//applet:IF_CRC32(APPLET_NOEXEC(crc32, cksum, BB_DIR_USR_BIN, BB_SUID_DROP, cksum))
  20/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
  21
  22//kbuild:lib-$(CONFIG_CKSUM) += cksum.o
  23//kbuild:lib-$(CONFIG_CRC32) += cksum.o
  24
  25//usage:#define cksum_trivial_usage
  26//usage:       "FILE..."
  27//usage:#define cksum_full_usage "\n\n"
  28//usage:       "Calculate CRC32 checksum of FILEs"
  29
  30#include "libbb.h"
  31#include "common_bufsiz.h"
  32
  33/* This is a NOEXEC applet. Be very careful! */
  34
  35#define IS_CKSUM (ENABLE_CKSUM && (!ENABLE_CRC32 || applet_name[1] == 'k'))
  36#define IS_CRC32 (ENABLE_CRC32 && (!ENABLE_CKSUM || applet_name[1] == 'r'))
  37
  38int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  39int cksum_main(int argc UNUSED_PARAM, char **argv)
  40{
  41        uint32_t *crc32_table = crc32_filltable(NULL, IS_CKSUM);
  42        int exit_code = EXIT_SUCCESS;
  43
  44#if ENABLE_DESKTOP
  45        getopt32(argv, ""); /* cksum coreutils 6.9 compat */
  46        argv += optind;
  47#else
  48        argv++;
  49#endif
  50
  51        setup_common_bufsiz();
  52        do {
  53                uint32_t crc;
  54                IF_CKSUM(off_t filesize;)
  55                const char *fname = *argv ? *argv : bb_msg_standard_input;
  56                int fd = open_or_warn_stdin(fname);
  57
  58                if (fd < 0) {
  59                        exit_code = EXIT_FAILURE;
  60                        continue;
  61                }
  62
  63                crc = IS_CKSUM ? 0 : 0xffffffff;
  64                IF_CKSUM(filesize = 0;)
  65#define read_buf bb_common_bufsiz1
  66                for (;;) {
  67                        int bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE);
  68                        if (bytes_read < 0)
  69                                bb_simple_perror_msg_and_die(fname);
  70                        if (bytes_read > 0) {
  71                                IF_CKSUM(filesize += bytes_read;)
  72                        } else {
  73                                IF_CKSUM(uoff_t t;)
  74
  75                                close(fd);
  76                                if (IS_CRC32)
  77                                        break;
  78#if ENABLE_CKSUM
  79                                fd = -1; /* break flag */
  80                                /* Checksum filesize bytes, LSB first */
  81                                t = filesize;
  82                                /*bytes_read = 0; - already is */
  83                                while (t != 0) {
  84                                        read_buf[bytes_read++] = (uint8_t)t;
  85                                        t >>= 8;
  86                                }
  87#endif
  88                        }
  89                        crc = (IS_CKSUM ? crc32_block_endian1 : crc32_block_endian0)(crc, read_buf, bytes_read, crc32_table);
  90                        if (ENABLE_CKSUM && fd < 0)
  91                                break;
  92                }
  93
  94                crc = ~crc;
  95#if ENABLE_CKSUM
  96                if (IS_CKSUM)
  97                        printf((*argv ? "%u %"OFF_FMT"u %s\n" : "%u %"OFF_FMT"u\n"),
  98                                (unsigned)crc, filesize, *argv);
  99                else
 100#endif
 101                        printf((*argv ? "%08x %s\n" : "%08x\n"),
 102                                (unsigned)crc, *argv);
 103        } while (*argv && *++argv);
 104
 105        fflush_stdout_and_exit(exit_code);
 106}
 107