From 77526f6728faad43f25359d107419081640b2b18 Mon Sep 17 00:00:00 2001
From: Willy Tarreau <w@1wt.eu>
Date: Tue, 3 Mar 2020 15:57:10 +0100
Subject: [PATCH] MINOR: tools: add new function dump_addr_and_bytes()

This function dumps <n> bytes from <addr> in hex form into buffer <buf>
enclosed in brackets after the address itself, formatted on 14 chars
including the "0x" prefix. This is meant to be used as a prefix for code
areas. For example: "0x7f10b6557690 [48 c7 c0 0f 00 00 00 0f]: "
It relies on may_access() to know if the bytes are dumpable, otherwise "--"
is emitted. An optional prefix is supported.

(cherry picked from commit 762fb3ec8e05ca7a61b28e8a876c194c9db591ef)
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
 include/common/standard.h |    1 +
 src/standard.c            |   25 +++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/include/common/standard.h b/include/common/standard.h
index ef4bf93..e8b6917 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -1496,6 +1496,7 @@ int dump_text(struct buffer *out, const char *buf, int bsize);
 int dump_binary(struct buffer *out, const char *buf, int bsize);
 int dump_text_line(struct buffer *out, const char *buf, int bsize, int len,
                    int *line, int ptr);
+void dump_addr_and_bytes(struct buffer *buf, const char *pfx, const void *addr, int n);
 void dump_hex(struct buffer *out, const char *pfx, const void *buf, int len, int unsafe);
 int may_access(const void *ptr);
 
diff --git a/src/standard.c b/src/standard.c
index b85cbab..a75ab88 100644
--- a/src/standard.c
+++ b/src/standard.c
@@ -4199,6 +4199,31 @@ void dump_hex(struct buffer *out, const char *pfx, const void *buf, int len, int
 	}
 }
 
+/* dumps <pfx> followed by <n> bytes from <addr> in hex form into buffer <buf>
+ * enclosed in brackets after the address itself, formatted on 14 chars
+ * including the "0x" prefix. This is meant to be used as a prefix for code
+ * areas. For example:
+ *    "0x7f10b6557690 [48 c7 c0 0f 00 00 00 0f]"
+ * It relies on may_access() to know if the bytes are dumpable, otherwise "--"
+ * is emitted. A NULL <pfx> will be considered empty.
+ */
+void dump_addr_and_bytes(struct buffer *buf, const char *pfx, const void *addr, int n)
+{
+	int ok = 0;
+	int i;
+
+	chunk_appendf(buf, "%s%#14lx [", pfx ? pfx : "", (long)addr);
+
+	for (i = 0; i < n; i++) {
+		if (i == 0 || (((long)(addr + i) ^ (long)(addr)) & 4096))
+			ok = may_access(addr + i);
+		if (ok)
+			chunk_appendf(buf, "%02x%s", ((uint8_t*)addr)[i], (i<n-1) ? " " : "]");
+		else
+			chunk_appendf(buf, "--%s", (i<n-1) ? " " : "]");
+	}
+}
+
 /* print a line of text buffer (limited to 70 bytes) to <out>. The format is :
  * <2 spaces> <offset=5 digits> <space or plus> <space> <70 chars max> <\n>
  * which is 60 chars per line. Non-printable chars \t, \n, \r and \e are
-- 
1.7.10.4