[PATCH v3 25/27] ubifs: introduce hexdump lib

Dongsheng Yang yangds.fnst at cn.fujitsu.com
Thu Nov 12 22:13:36 PST 2015


Introduce a hexdump lib to allow us to dump data in hex format

Signed-off-by: Dongsheng Yang <yangds.fnst at cn.fujitsu.com>
---
 ubifs-utils/include/hexdump.h |  21 +++++
 ubifs-utils/lib/hexdump.c     | 200 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 221 insertions(+)
 create mode 100644 ubifs-utils/include/hexdump.h
 create mode 100644 ubifs-utils/lib/hexdump.c

diff --git a/ubifs-utils/include/hexdump.h b/ubifs-utils/include/hexdump.h
new file mode 100644
index 0000000..f5f2800
--- /dev/null
+++ b/ubifs-utils/include/hexdump.h
@@ -0,0 +1,21 @@
+#ifndef __UBIFS_HEXDUMP_H__
+#define __UBIFS_HEXDUMP_H__
+
+#include "ubifs_common.h"
+
+static const char hex_asc[] = "0123456789abcdef";
+static const char hex_asc_upper[] = "0123456789ABCDEF";
+
+#define hex_asc_lo(x)	hex_asc[((x) & 0x0f)]
+#define hex_asc_hi(x)	hex_asc[((x) & 0xf0) >> 4]
+
+enum {
+	DUMP_PREFIX_NONE,
+	DUMP_PREFIX_ADDRESS,
+	DUMP_PREFIX_OFFSET
+};
+
+void print_hex_dump(const char *prefix_str, int prefix_type,
+		    int rowsize, int groupsize,
+		    const void *buf, size_t len, int ascii);
+#endif
diff --git a/ubifs-utils/lib/hexdump.c b/ubifs-utils/lib/hexdump.c
new file mode 100644
index 0000000..c58f7cc
--- /dev/null
+++ b/ubifs-utils/lib/hexdump.c
@@ -0,0 +1,200 @@
+/*
+ * 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 "hexdump.h"
+#define PROGRAM_NAME "hexdump"
+#include "common.h"
+/**
+ * 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, int 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 ? " " : "",
+				       (unsigned long long)*(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 ? " " : "",
+				       *(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 ? " " : "",
+				       *(ptr2 + j));
+			if (ret >= linebuflen - lx)
+				goto overflow1;
+			lx += ret;
+		}
+	} else {
+		for (j = 0; j < len; j++) {
+			if (linebuflen < lx + 3)
+				goto overflow2;
+			ch = ptr[j];
+			linebuf[lx++] = hex_asc_hi(ch);
+			linebuf[lx++] = hex_asc_lo(ch);
+			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, int 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;
+		}
+	}
+}
-- 
1.8.4.2




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