From cc32246d2aa7cc6ecc2071d1d6ea3c6a7015f2f2 Mon Sep 17 00:00:00 2001
From: Christos Zoulas <christos@zoulas.com>
Date: Fri, 22 Jun 2018 20:39:49 +0000
Subject: [PATCH] Add quad indirect offsets

---
 ChangeLog        |  4 ++++
 doc/magic.man    | 23 +++++++++++++++++++----
 src/apprentice.c |  8 +++++++-
 src/softmagic.c  | 22 ++++++++++++++++++++--
 4 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index dccf3e0312..194b33600f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2018-06-22  16:38  Christos Zoulas <christos@zoulas.com>
+
+	* Add Quad indirect offsets
+
 2018-05-24  14:10  Christos Zoulas <christos@zoulas.com>
 
 	* Enable parsing of ELF dynamic sections to handle PIE better
diff --git a/doc/magic.man b/doc/magic.man
index 1b89879f6f..15165daa5e 100644
--- a/doc/magic.man
+++ b/doc/magic.man
@@ -1,5 +1,6 @@
-.\" $File: magic.man,v 1.92 2017/11/04 01:11:32 christos Exp $
-.Dd Noveber 3, 2017
+.It S2
+.\" $File: magic.man,v 1.93 2018/06/22 20:39:49 christos Exp $
+.Dd June 22, 2018
 .Dt MAGIC __FSECTION__
 .Os
 .\" install as magic.4 on USG, magic.5 on V7, Berkeley and Linux systems.
@@ -553,12 +554,12 @@ the file.
 The value at that offset is read, and is used again as an offset
 in the file.
 Indirect offsets are of the form:
-.Em (( x [[.,][bislBISL]][+\-][ y ]) .
+.Em (( x [[.,][bBcCeEfFgGhHiIlmsSqQ]][+\-][ y ]) .
 The value of
 .Em x
 is used as an offset in the file.
 A byte, id3 length, short or long is read at that offset depending on the
-.Em [bislBISLm]
+.Em [bBcCeEfFgGhHiIlmsSqQ]
 type specifier.
 The value is treated as signed if
 .Dq ,
@@ -575,6 +576,20 @@ To that number the value of
 .Em y
 is added and the result is used as an offset in the file.
 The default type if one is not specified is long.
+The following types are recognized:
+.Bl -column -offset indent "Type" "Half/Short" "Little" "Size"
+.It Sy Type	Sy Mnemonic	Sy Endian	Sy Size
+.It bcBc	Byte/Char	N/A	1
+.It efg	Double	Little	8
+.It EFG	Double	Big	8
+.It hs	Half/Short	Little	2
+.It HS	Half/Short	Big	2
+.It i	ID3	Little	4
+.It I	ID3	Big	4
+.It m	Middle	Middle	4
+.It q	Quad	Little	8
+.It Q	Quad	Big	8
+.El
 .Pp
 That way variable length structures can be examined:
 .Bd -literal -offset indent
diff --git a/src/apprentice.c b/src/apprentice.c
index 2700ae9b79..ea8d0b222e 100644
--- a/src/apprentice.c
+++ b/src/apprentice.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef	lint
-FILE_RCSID("@(#)$File: apprentice.c,v 1.271 2018/04/15 19:57:59 christos Exp $")
+FILE_RCSID("@(#)$File: apprentice.c,v 1.272 2018/06/22 20:39:50 christos Exp $")
 #endif	/* lint */
 
 #include "magic.h"
@@ -1980,6 +1980,12 @@ parse(struct magic_set *ms, struct magic_entry *me, const char *line,
 			case 'I':
 				m->in_type = FILE_BEID3;
 				break;
+			case 'q':
+				m->in_type = FILE_LEQUAD;
+				break;
+			case 'Q':
+				m->in_type = FILE_BEQUAD;
+				break;
 			default:
 				if (ms->flags & MAGIC_CHECK)
 					file_magwarn(ms,
diff --git a/src/softmagic.c b/src/softmagic.c
index bba0a77ad0..9a5db9d3e2 100644
--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef	lint
-FILE_RCSID("@(#)$File: softmagic.c,v 1.261 2018/05/24 18:09:17 christos Exp $")
+FILE_RCSID("@(#)$File: softmagic.c,v 1.262 2018/06/22 20:39:50 christos Exp $")
 #endif	/* lint */
 
 #include "magic.h"
@@ -1535,6 +1535,14 @@ mget(struct magic_set *ms, struct magic *m, const struct buffer *b,
 			case FILE_MELONG:
 				off = SEXT(sgn,32,ME32(q));
 				break;
+			case FILE_BEQUAD:
+				off = SEXT(sgn,64,BE64(q));
+				break;
+			case FILE_LEQUAD:
+				off = SEXT(sgn,64,LE64(q));
+				break;
+			default:
+				abort();
 			}
 			if ((ms->flags & MAGIC_DEBUG) != 0)
 				fprintf(stderr, "indirect offs=%jd\n", off);
@@ -1588,8 +1596,18 @@ mget(struct magic_set *ms, struct magic *m, const struct buffer *b,
 				return 0;
 			offset = do_ops(m, SEXT(sgn,32,p->l), off);
 			break;
-		default:
+		case FILE_LEQUAD:
+			if (OFFSET_OOB(nbytes, offset, 8))
+				return 0;
+			offset = do_ops(m, SEXT(sgn,64,LE64(p)), off);
+			break;
+		case FILE_BEQUAD:
+			if (OFFSET_OOB(nbytes, offset, 8))
+				return 0;
+			offset = do_ops(m, SEXT(sgn,64,BE64(p)), off);
 			break;
+		default:
+			abort();
 		}
 
 		if (m->flag & INDIROFFADD) {