diff options
Diffstat (limited to 'lib/hexdump.c')
| -rw-r--r-- | lib/hexdump.c | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/lib/hexdump.c b/lib/hexdump.c new file mode 100644 index 0000000..f07c0db --- /dev/null +++ b/lib/hexdump.c @@ -0,0 +1,201 @@ +/* + * 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/module.h> + +const char hex_asc[] = "0123456789abcdef"; +EXPORT_SYMBOL(hex_asc); + +/** + * 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), 1); + * + * example output buffer: + * 40 41 42 43 44 45 46 47 48 49 4a 4b 4c 4d 4e 4f @ABCDEFGHIJKLMNO + */ +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, + "%16.16llx ", (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, + "%8.8x ", *(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, + "%4.4x ", *(ptr2 + j)); + ascii_column = 5 * ngroups + 2; + break; + } + + default: + for (j = 0; (j < rowsize) && (j < len) && (lx + 4) < linebuflen; + j++) { + ch = ptr[j]; + linebuf[lx++] = hex_asc_hi(ch); + linebuf[lx++] = hex_asc_lo(ch); + linebuf[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 < rowsize) && (j < len) && (lx + 2) < linebuflen; j++) + linebuf[lx++] = (isascii(ptr[j]) && isprint(ptr[j])) ? ptr[j] + : '.'; +nil: + linebuf[lx++] = '\0'; +} +EXPORT_SYMBOL(hex_dump_to_buffer); + +/** + * print_hex_dump - print a text hex dump to syslog for a binary blob of data + * @level: kernel log level (e.g. KERN_DEBUG) + * @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 kernel log at the specified kernel log level, 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(KERN_DEBUG, "raw data: ", DUMP_PREFIX_ADDRESS, + * 16, 1, frame->data, frame->len, 1); + * + * 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 *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[200]; + + 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, + (int)(2 * sizeof(void *)), 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); + +/** + * 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(), with log level of KERN_DEBUG, + * 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(KERN_DEBUG, prefix_str, prefix_type, 16, 1, + buf, len, 1); +} +EXPORT_SYMBOL(print_hex_dump_bytes); |
