hexdump.c

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/*
 * lib/hexdump.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 */

#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/kernel.h>
#include <linux/export.h>

const char hex_asc[] = "0123456789abcdef";
EXPORT_SYMBOL(hex_asc);

int hex_to_bin(char ch)
{
    if ((ch >= '0') && (ch <= '9'))
        return ch - '0';
    ch = tolower(ch);
    if ((ch >= 'a') && (ch <= 'f'))
        return ch - 'a' + 10;
    return -1;
}
EXPORT_SYMBOL(hex_to_bin);

int hex2bin(u8 *dst, const char *src, size_t count)
{
    while (count--) {
        int hi = hex_to_bin(*src++);
        int lo = hex_to_bin(*src++);

        if ((hi < 0) || (lo < 0))
            return -1;

        *dst++ = (hi << 4) | lo;
    }
    return 0;
}
EXPORT_SYMBOL(hex2bin);

void hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
            int groupsize, char *linebuf, size_t linebuflen,
            bool ascii)
{
    const u8 *ptr = buf;
    u8 ch;
    int j, lx = 0;
    int ascii_column;

    if (rowsize != 16 && rowsize != 32)
        rowsize = 16;

    if (!len)
        goto nil;
    if (len > rowsize)      /* limit to one line at a time */
        len = rowsize;
    if ((len % groupsize) != 0) /* no mixed size output */
        groupsize = 1;

    switch (groupsize) {
    case 8: {
        const u64 *ptr8 = buf;
        int ngroups = len / groupsize;

        for (j = 0; j < ngroups; j++)
            lx += scnprintf(linebuf + lx, linebuflen - lx,
                    "%s%16.16llx", j ? " " : "",
                    (unsigned long long)*(ptr8 + j));
        ascii_column = 17 * ngroups + 2;
        break;
    }

    case 4: {
        const u32 *ptr4 = buf;
        int ngroups = len / groupsize;

        for (j = 0; j < ngroups; j++)
            lx += scnprintf(linebuf + lx, linebuflen - lx,
                    "%s%8.8x", j ? " " : "", *(ptr4 + j));
        ascii_column = 9 * ngroups + 2;
        break;
    }

    case 2: {
        const u16 *ptr2 = buf;
        int ngroups = len / groupsize;

        for (j = 0; j < ngroups; j++)
            lx += scnprintf(linebuf + lx, linebuflen - lx,
                    "%s%4.4x", j ? " " : "", *(ptr2 + j));
        ascii_column = 5 * ngroups + 2;
        break;
    }

    default:
        for (j = 0; (j < len) && (lx + 3) <= linebuflen; j++) {
            ch = ptr[j];
            linebuf[lx++] = hex_asc_hi(ch);
            linebuf[lx++] = hex_asc_lo(ch);
            linebuf[lx++] = ' ';
        }
        if (j)
            lx--;

        ascii_column = 3 * rowsize + 2;
        break;
    }
    if (!ascii)
        goto nil;

    while (lx < (linebuflen - 1) && lx < (ascii_column - 1))
        linebuf[lx++] = ' ';
    for (j = 0; (j < len) && (lx + 2) < linebuflen; j++) {
        ch = ptr[j];
        linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
    }
nil:
    linebuf[lx++] = '\0';
}
EXPORT_SYMBOL(hex_dump_to_buffer);

#ifdef CONFIG_PRINTK

void print_hex_dump(const char *level, const char *prefix_str, int prefix_type,
            int rowsize, int groupsize,
            const void *buf, size_t len, bool ascii)
{
    const u8 *ptr = buf;
    int i, linelen, remaining = len;
    unsigned char linebuf[32 * 3 + 2 + 32 + 1];

    if (rowsize != 16 && rowsize != 32)
        rowsize = 16;

    for (i = 0; i < len; i += rowsize) {
        linelen = min(remaining, rowsize);
        remaining -= rowsize;

        hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize,
                   linebuf, sizeof(linebuf), ascii);

        switch (prefix_type) {
        case DUMP_PREFIX_ADDRESS:
            printk("%s%s%p: %s\n",
                   level, prefix_str, ptr + i, linebuf);
            break;
        case DUMP_PREFIX_OFFSET:
            printk("%s%s%.8x: %s\n", level, prefix_str, i, linebuf);
            break;
        default:
            printk("%s%s%s\n", level, prefix_str, linebuf);
            break;
        }
    }
}
EXPORT_SYMBOL(print_hex_dump);

void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
              const void *buf, size_t len)
{
    print_hex_dump(KERN_DEBUG, prefix_str, prefix_type, 16, 1,
               buf, len, true);
}
EXPORT_SYMBOL(print_hex_dump_bytes);
#endif