1 /*
2  * Copyright (c) 2000-2008 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 /*
29  *	File: libkern/kernel_mach_header.h
30  *
31  *	Definitions for accessing mach-o headers.
32  *
33  * NOTE:	These functions work on Mach-O headers compatible with
34  *		the currently running kernel, and cannot be used against mach
35  *		headers other than that of the currently running kernel.
36  *
37  */
38 
39 #ifndef _KERNEL_MACH_HEADER_
40 #define _KERNEL_MACH_HEADER_
41 
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 
46 #include <mach/mach_types.h>
47 #include <mach-o/loader.h>
48 #include <mach-o/nlist.h>
49 #include <mach-o/reloc.h>
50 
51 #if     !KERNEL
52 #error this header for kernel use only
53 #endif
54 
55 #if defined(__LP64__)
56 
57 typedef struct mach_header_64   kernel_mach_header_t;
58 typedef struct segment_command_64 kernel_segment_command_t;
59 typedef struct section_64               kernel_section_t;
60 typedef struct nlist_64         kernel_nlist_t;
61 
62 #define MH_MAGIC_KERNEL         MH_MAGIC_64
63 #define LC_SEGMENT_KERNEL       LC_SEGMENT_64
64 
65 #else
66 
67 typedef struct mach_header              kernel_mach_header_t;
68 typedef struct segment_command  kernel_segment_command_t;
69 typedef struct section                  kernel_section_t;
70 typedef struct nlist            kernel_nlist_t;
71 
72 #define MH_MAGIC_KERNEL         MH_MAGIC
73 #define LC_SEGMENT_KERNEL               LC_SEGMENT
74 #define SECT_CONSTRUCTOR                "__constructor"
75 #define SECT_DESTRUCTOR                 "__destructor"
76 
77 #endif
78 
79 #define SECT_MODINITFUNC                "__mod_init_func"
80 #define SECT_MODTERMFUNC                "__mod_term_func"
81 
82 extern kernel_mach_header_t _mh_execute_header;
83 
84 /*
85  * If the 'MH_DYLIB_IN_CACHE' bit is set in a kernel or kext mach-o header flag,
86  * then that mach-o has been linked by the new KernelCollectionBuilder into
87  * an MH_FILESET kernel collection. This bit is typically reserved for dylibs
88  * that are part of the dyld-shared-cache, but when applied to constituents of
89  * a kernel collection, it has this special meaning.
90  */
91 #define kernel_mach_header_is_in_fileset(_mh) ((_mh)->flags & MH_DYLIB_IN_CACHE)
92 
93 vm_offset_t getlastaddr(kernel_mach_header_t *header);
94 vm_offset_t getlastkerneladdr(void);
95 
96 kernel_segment_command_t *firstseg(void);
97 kernel_segment_command_t *firstsegfromheader(kernel_mach_header_t *header);
98 kernel_segment_command_t *nextsegfromheader(
99 	kernel_mach_header_t    *header,
100 	kernel_segment_command_t        *seg);
101 kernel_segment_command_t *getsegbyname(const char *seg_name);
102 kernel_segment_command_t *getsegbynamefromheader(
103 	kernel_mach_header_t    *header,
104 	const char              *seg_name);
105 void *getsegdatafromheader(kernel_mach_header_t *, const char *, unsigned long *);
106 kernel_section_t *getsectbyname(const char *seg_name, const char *sect_name);
107 kernel_section_t *getsectbynamefromheader(
108 	kernel_mach_header_t    *header,
109 	const char              *seg_name,
110 	const char              *sect_name);
111 kernel_section_t *getsectbynamefromseg(
112 	kernel_segment_command_t        *sgp,
113 	const char                      *segname,
114 	const char                      *sectname);
115 uint32_t getsectoffsetfromheader(
116 	kernel_mach_header_t *mhp,
117 	const char *segname,
118 	const char *sectname);
119 void *getsectdatafromheader(kernel_mach_header_t *, const char *, const char *, unsigned long *);
120 kernel_section_t *firstsect(kernel_segment_command_t *sgp);
121 kernel_section_t *nextsect(kernel_segment_command_t *sgp, kernel_section_t *sp);
122 void *getcommandfromheader(kernel_mach_header_t *, uint32_t);
123 void *getuuidfromheader(kernel_mach_header_t *, unsigned long *);
124 
125 bool kernel_text_contains(vm_offset_t);
126 
127 #ifdef __cplusplus
128 }
129 #endif
130 
131 #endif  /* _KERNEL_MACH_HEADER_ */
132