1 files changed, 104 insertions, 0 deletions
diff --git a/lib/hexdump.c b/lib/hexdump.c
new file mode 100644
index 00000000000..e6da5b7fc29
--- /dev/null
+++ b/lib/hexdump.c
@@ -0,0 +1,104 @@
+/*
+ * 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>
+
+/**
+ * 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
+ * @linebuf: where to put the converted data
+ * @linebuflen: total size of @linebuf, including space for terminating NUL
+ *
+ * hex_dump_to_buffer() works on one "line" of output at a time, i.e.,
+ * 16 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, linebuf, sizeof(linebuf));
+ *
+ * example output buffer:
+ * 40414243 44454647 48494a4b 4c4d4e4f  @ABCDEFGHIJKLMNO
+ */
+void hex_dump_to_buffer(const void *buf, size_t len, char *linebuf,
+			size_t linebuflen)
+{
+	const u8 *ptr = buf;
+	u8 ch;
+	int j, lx = 0;
+
+	for (j = 0; (j < 16) && (j < len) && (lx + 3) < linebuflen; j++) {
+		if (j && !(j % 4))
+			linebuf[lx++] = ' ';
+		ch = ptr[j];
+		linebuf[lx++] = hex_asc(ch >> 4);
+		linebuf[lx++] = hex_asc(ch & 0x0f);
+	}
+	if ((lx + 2) < linebuflen) {
+		linebuf[lx++] = ' ';
+		linebuf[lx++] = ' ';
+	}
+	for (j = 0; (j < 16) && (j < len) && (lx + 2) < linebuflen; j++)
+		linebuf[lx++] = isprint(ptr[j]) ? ptr[j] : '.';
+	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_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
+ *
+ * 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.
+ *
+ * E.g.:
+ *   print_hex_dump(KERN_DEBUG, DUMP_PREFIX_ADDRESS, frame->data, frame->len);
+ *
+ * Example output using %DUMP_PREFIX_OFFSET:
+ * 0009ab42: 40414243 44454647 48494a4b 4c4d4e4f  @ABCDEFGHIJKLMNO
+ * Example output using %DUMP_PREFIX_ADDRESS:
+ * ffffffff88089af0: 70717273 74757677 78797a7b 7c7d7e7f  pqrstuvwxyz{|}~.
+ */
+void print_hex_dump(const char *level, int prefix_type, void *buf, size_t len)
+{
+	u8 *ptr = buf;
+	int i, linelen, remaining = len;
+	unsigned char linebuf[100];
+
+	for (i = 0; i < len; i += 16) {
+		linelen = min(remaining, 16);
+		remaining -= 16;
+		hex_dump_to_buffer(ptr + i, linelen, linebuf, sizeof(linebuf));
+
+		switch (prefix_type) {
+		case DUMP_PREFIX_ADDRESS:
+			printk("%s%*p: %s\n", level,
+				(int)(2 * sizeof(void *)), ptr + i, linebuf);
+			break;
+		case DUMP_PREFIX_OFFSET:
+			printk("%s%.8x: %s\n", level, i, linebuf);
+			break;
+		default:
+			printk("%s%s\n", level, linebuf);
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(print_hex_dump);