From 0ebb511b3ea1b4b00410cedfec5c6bef47d4831a Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Mon, 5 Dec 2016 00:10:57 +0100
Subject: [PATCH] MINOR: tools: add a generic hexdump function for debugging

debug_hexdump() prints to the requested output stream (typically stdout
or stderr) an hex dump of the blob passed in argument. This is useful
to help debug binary protocols.
---
 include/common/standard.h |  6 ++++++
 src/standard.c            | 45 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/include/common/standard.h b/include/common/standard.h
index e16b30414..68244dbe7 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -24,6 +24,7 @@
 
 #include <limits.h>
 #include <string.h>
+#include <stdio.h>
 #include <time.h>
 #include <sys/time.h>
 #include <sys/types.h>
@@ -990,6 +991,11 @@ char *env_expand(char *in);
  */
 #define fddebug(msg...) do { char *_m = NULL; memprintf(&_m, ##msg); if (_m) write(-1, _m, strlen(_m)); free(_m); } while (0)
 
+/* displays a <len> long memory block at <buf>, assuming first byte of <buf>
+ * has address <baseaddr>. The output is emitted to file <out>.
+ */
+void debug_hexdump(FILE *out, char *buf, unsigned int baseaddr, int len);
+
 /* used from everywhere just to drain results we don't want to read and which
  * recent versions of gcc increasingly and annoyingly complain about.
  */
diff --git a/src/standard.c b/src/standard.c
index 079aef8f7..910e1c298 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -3765,6 +3765,51 @@ int dump_text_line(struct chunk *out, const char *buf, int bsize, int len,
 	return ptr;
 }
 
+/* displays a <len> long memory block at <buf>, assuming first byte of <buf>
+ * has address <baseaddr>. The output is emitted to file <out>.
+ */
+void debug_hexdump(FILE *out, char *buf, unsigned int baseaddr, int len)
+{
+	unsigned int i, j;
+	int b;
+
+	for (i = 0; i < (len + (baseaddr & 15)); i += 16) {
+		b = i - (baseaddr & 15);
+		fprintf(out, "%08x: ", i + (baseaddr & ~15));
+		for (j = 0; j < 8; j++) {
+			if (b + j >= 0 && b + j < len)
+				fprintf(out, "%02x ", (unsigned char)buf[b + j]);
+			else
+				fprintf(out, "   ");
+		}
+
+		if (b + j >= 0 && b + j < len)
+			fputc('-', out);
+		else
+			fputc(' ', out);
+
+		for (j = 8; j < 16; j++) {
+			if (b + j >= 0 && b + j < len)
+				fprintf(out, " %02x", (unsigned char)buf[b + j]);
+			else
+				fprintf(out, "   ");
+		}
+
+		fprintf(out, "   ");
+		for (j = 0; j < 16; j++) {
+			if (b + j >= 0 && b + j < len) {
+				if (isprint((unsigned char)buf[b + j]))
+					fputc((unsigned char)buf[b + j], out);
+				else
+					fputc('.', out);
+			}
+			else
+				fputc(' ', out);
+		}
+		fputc('\n', out);
+	}
+}
+
 /*
  * Local variables:
  *  c-indent-level: 8