// SPDX-License-Identifier: GPL-2.0+
/*
 * 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 <common.h>
#include <hexdump.h>
#include <linux/ctype.h>
#include <linux/compat.h>
#include <linux/log2.h>
#include <asm/unaligned.h>

const char hex_asc[] = "0123456789abcdef";
const char hex_asc_upper[] = "0123456789ABCDEF";

#ifdef CONFIG_HEXDUMP
/**
 * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 * @rowsize: number of bytes to print per line; must be 16 or 32
 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 * @linebuf: where to put the converted data
 * @linebuflen: total size of @linebuf, including space for terminating NUL
 * @ascii: include ASCII after the hex output
 *
 * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
 * 16 or 32 bytes of input data converted to hex + ASCII output.
 *
 * Given a buffer of u8 data, hex_dump_to_buffer() converts the input data
 * to a hex + ASCII dump at the supplied memory location.
 * The converted output is always NUL-terminated.
 *
 * E.g.:
 *   hex_dump_to_buffer(frame->data, frame->len, 16, 1,
 *                      linebuf, sizeof(linebuf), true);
 *
 * example output buffer:
 * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 *
 * Return:
 * The amount of bytes placed in the buffer without terminating NUL. If the
 * output was truncated, then the return value is the number of bytes
 * (excluding the terminating NUL) which would have been written to the final
 * string if enough space had been available.
 */
int 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;
        int ngroups;
        u8 ch;
        int j, lx = 0;
        int ascii_column;
        int ret;

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

        if (len > rowsize)              /* limit to one line at a time */
                len = rowsize;
        if (!is_power_of_2(groupsize) || groupsize > 8)
                groupsize = 1;
        if ((len % groupsize) != 0)     /* no mixed size output */
                groupsize = 1;

        ngroups = len / groupsize;
        ascii_column = rowsize * 2 + rowsize / groupsize + 1;

        if (!linebuflen)
                goto overflow1;

        if (!len)
                goto nil;

        if (groupsize == 8) {
                const u64 *ptr8 = buf;

                for (j = 0; j < ngroups; j++) {
                        ret = snprintf(linebuf + lx, linebuflen - lx,
                                       "%s%16.16llx", j ? " " : "",
                                       get_unaligned(ptr8 + j));
                        if (ret >= linebuflen - lx)
                                goto overflow1;
                        lx += ret;
                }
        } else if (groupsize == 4) {
                const u32 *ptr4 = buf;

                for (j = 0; j < ngroups; j++) {
                        ret = snprintf(linebuf + lx, linebuflen - lx,
                                       "%s%8.8x", j ? " " : "",
                                       get_unaligned(ptr4 + j));
                        if (ret >= linebuflen - lx)
                                goto overflow1;
                        lx += ret;
                }
        } else if (groupsize == 2) {
                const u16 *ptr2 = buf;

                for (j = 0; j < ngroups; j++) {
                        ret = snprintf(linebuf + lx, linebuflen - lx,
                                       "%s%4.4x", j ? " " : "",
                                       get_unaligned(ptr2 + j));
                        if (ret >= linebuflen - lx)
                                goto overflow1;
                        lx += ret;
                }
        } else {
                for (j = 0; j < len; j++) {
                        if (linebuflen < lx + 2)
                                goto overflow2;
                        ch = ptr[j];
                        linebuf[lx++] = hex_asc_hi(ch);
                        if (linebuflen < lx + 2)
                                goto overflow2;
                        linebuf[lx++] = hex_asc_lo(ch);
                        if (linebuflen < lx + 2)
                                goto overflow2;
                        linebuf[lx++] = ' ';
                }
                if (j)
                        lx--;
        }
        if (!ascii)
                goto nil;

        while (lx < ascii_column) {
                if (linebuflen < lx + 2)
                        goto overflow2;
                linebuf[lx++] = ' ';
        }
        for (j = 0; j < len; j++) {
                if (linebuflen < lx + 2)
                        goto overflow2;
                ch = ptr[j];
                linebuf[lx++] = (isascii(ch) && isprint(ch)) ? ch : '.';
        }
nil:
        linebuf[lx] = '\0';
        return lx;
overflow2:
        linebuf[lx++] = '\0';
overflow1:
        return ascii ? ascii_column + len : (groupsize * 2 + 1) * ngroups - 1;
}

/**
 * print_hex_dump - print a text hex dump to syslog for a binary blob of data
 * @prefix_str: string to prefix each line with;
 *  caller supplies trailing spaces for alignment if desired
 * @prefix_type: controls whether prefix of an offset, address, or none
 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 * @rowsize: number of bytes to print per line; must be 16 or 32
 * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 * @ascii: include ASCII after the hex output
 *
 * Given a buffer of u8 data, print_hex_dump() prints a hex + ASCII dump
 * to the stdio, with an optional leading prefix.
 *
 * print_hex_dump() works on one "line" of output at a time, i.e.,
 * 16 or 32 bytes of input data converted to hex + ASCII output.
 * print_hex_dump() iterates over the entire input @buf, breaking it into
 * "line size" chunks to format and print.
 *
 * E.g.:
 *   print_hex_dump("raw data: ", DUMP_PREFIX_ADDRESS, 16, 1, frame->data,
 *                  frame->len, true);
 *
 * Example output using %DUMP_PREFIX_OFFSET and 1-byte mode:
 * 0009ab42: 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f  @ABCDEFGHIJKLMNO
 * Example output using %DUMP_PREFIX_ADDRESS and 4-byte mode:
 * ffffffff88089af0: 73727170 77767574 7b7a7978 7f7e7d7c  pqrstuvwxyz{|}~.
 */
void print_hex_dump(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;
        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:
                        printf("%s%p: %s\n", prefix_str, ptr + i, linebuf);
                        break;
                case DUMP_PREFIX_OFFSET:
                        printf("%s%.8x: %s\n", prefix_str, i, linebuf);
                        break;
                default:
                        printf("%s%s\n", prefix_str, linebuf);
                        break;
                }
        }
}

/**
 * print_hex_dump_bytes - shorthand form of print_hex_dump() with default params
 * @prefix_str: string to prefix each line with;
 *  caller supplies trailing spaces for alignment if desired
 * @prefix_type: controls whether prefix of an offset, address, or none
 *  is printed (%DUMP_PREFIX_OFFSET, %DUMP_PREFIX_ADDRESS, %DUMP_PREFIX_NONE)
 * @buf: data blob to dump
 * @len: number of bytes in the @buf
 *
 * Calls print_hex_dump(), rowsize of 16, groupsize of 1,
 * and ASCII output included.
 */
void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
                          const void *buf, size_t len)
{
        print_hex_dump(prefix_str, prefix_type, 16, 1, buf, len, true);
}
#else
/*
 * Some code in U-Boot copy-pasted from Linux kernel uses both
 * functions below so to keep stuff compilable we keep these stubs here.
 */
void print_hex_dump(const char *prefix_str, int prefix_type,
                                  int rowsize, int groupsize, const void *buf,
                                  size_t len, bool ascii)
{
}

void print_hex_dump_bytes(const char *prefix_str, int prefix_type,
                                        const void *buf, size_t len)
{
}
#endif /* CONFIG_HEXDUMP */