--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * lib/hexdump.c
+ */
+
+#include <stdio.h>
+
+#include "linux_types.h"
+#include "defs.h"
+
+#define __get_unaligned_t(type, ptr) ({ \
+ const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
+ __pptr->x; \
+})
+
+#define get_unaligned(ptr) __get_unaligned_t(typeof(*(ptr)), (ptr))
+
+const char hex_asc[] = "0123456789abcdef";
+
+#define hex_asc_lo(x) hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x) hex_asc[((x) & 0xf0) >> 4]
+
+void print_hex_dump(const char *prefix_str, int prefix_type,
+ int rowsize, int groupsize,
+ const void *buf, size_t len, bool ascii);
+/**
+ * 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.
+ */
+static 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 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, 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;
+ }
+ }
+}
projects / mtd-utils.git / commitdiff