imgact_binmisc.h revision 266272
1/*-
2 * Copyright (c) 2013 Stacey D. Son
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 *
25 * $FreeBSD: stable/10/sys/sys/imgact_binmisc.h 266272 2014-05-16 21:56:33Z sbruno $
26 */
27
28#ifndef	_IMGACT_BINMISC_H_
29#define	_IMGACT_BINMISC_H_
30
31/**
32 * Miscellaneous binary interpreter image activator.
33 */
34
35#include <sys/param.h>	/* for MAXPATHLEN */
36
37/*
38 * Imgact bin misc parameters.
39 */
40#define	IBE_VERSION	1	/* struct ximgact_binmisc_entry version. */
41#define	IBE_NAME_MAX	32	/* Max size for entry name. */
42#define	IBE_MAGIC_MAX	256	/* Max size for header magic and mask. */
43#define	IBE_ARG_LEN_MAX	256	/* Max space for optional interpreter command-
44				   line argruments seperated by white space */
45#define	IBE_INTERP_LEN_MAX	(MAXPATHLEN + IBE_ARG_LEN_MAX)
46#define	IBE_MAX_ENTRIES	64	/* Max number of interpreter entries. */
47
48/*
49 * Imgact bin misc interpreter entry flags.
50 */
51#define	IBF_ENABLED	0x0001	/* Entry is active. */
52#define	IBF_USE_MASK	0x0002	/* Use mask on header magic field. */
53
54/*
55 * Used with sysctlbyname() to pass imgact bin misc entries in and out of the
56 * kernel.
57 */
58typedef struct ximgact_binmisc_entry {
59	uint32_t xbe_version;	/* Struct version(IBE_VERSION) */
60	uint32_t xbe_flags;	/* Entry flags (IBF_*) */
61	uint32_t xbe_moffset;	/* Magic offset in header */
62	uint32_t xbe_msize;	/* Magic size */
63	uint32_t spare[3];	/* Spare fields for future use */
64	char xbe_name[IBE_NAME_MAX];	/* Unique interpreter name */
65	char xbe_interpreter[IBE_INTERP_LEN_MAX]; /* Interpreter path + args */
66	uint8_t xbe_magic[IBE_MAGIC_MAX]; /* Header Magic */
67	uint8_t xbe_mask[IBE_MAGIC_MAX]; /* Magic Mask */
68} ximgact_binmisc_entry_t;
69
70/*
71 * sysctl() command names.
72 */
73#define	IBE_SYSCTL_NAME		"kern.binmisc"
74
75#define	IBE_SYSCTL_NAME_ADD	IBE_SYSCTL_NAME ".add"
76#define	IBE_SYSCTL_NAME_REMOVE	IBE_SYSCTL_NAME ".remove"
77#define	IBE_SYSCTL_NAME_DISABLE	IBE_SYSCTL_NAME ".disable"
78#define	IBE_SYSCTL_NAME_ENABLE	IBE_SYSCTL_NAME ".enable"
79#define	IBE_SYSCTL_NAME_LOOKUP	IBE_SYSCTL_NAME ".lookup"
80#define	IBE_SYSCTL_NAME_LIST	IBE_SYSCTL_NAME ".list"
81
82#define	KMOD_NAME	"imgact_binmisc"
83
84/*
85 * Examples of manipulating the interpreter table using sysctlbyname(3):
86 *
87 * #include <sys/imgact_binmisc.h>
88 *
89 * #define LLVM_MAGIC  "BC\xc0\xde"
90 *
91 * #define MIPS64_ELF_MAGIC	"\x7f\x45\x4c\x46\x02\x02\x01\x00\x00\x00" \
92 *				"\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08"
93 * #define MIPS64_ELF_MASK	"\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff" \
94 *				"\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff"
95 *
96 * ximgact_binmisc_entry_t xbe, *xbep, out_xbe;
97 * size_t size = 0, osize;
98 * int error, i;
99 *
100 * // Add image activator for LLVM byte code
101 * bzero(&xbe, sizeof(xbe));
102 * xbe.xbe_version = IBE_VERSION;
103 * xbe.xbe_flags = IBF_ENABLED;
104 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX);
105 * strlcpy(xbe.xbe_interpreter, "/usr/bin/lli --fake-arg0=#a",
106 *     IBE_INTERP_LEN_MAX);
107 * xbe.xbe_moffset = 0;
108 * xbe.xbe_msize = 4;
109 * memcpy(xbe.xbe_magic, LLVM_MAGIC, xbe.xbe_msize);
110 * error = sysctlbyname(IBE_SYSCTL_NAME_ADD, NULL, NULL, &xbe, sizeof(xbe));
111 *
112 * // Add image activator for mips64 ELF binaries to use qemu user mode
113 * bzero(&xbe, sizeof(xbe));
114 * xbe.xbe_version = IBE_VERSION;
115 * xbe.xbe_flags = IBF_ENABLED | IBF_USE_MASK;
116 * strlcpy(xbe.xbe_name, "mips64elf", IBE_NAME_MAX);
117 * strlcpy(xbe.xbe_interpreter, "/usr/local/bin/qemu-mips64",
118 *	IBE_INTERP_LEN_MAX);
119 * xbe.xbe_moffset = 0;
120 * xbe.xbe_msize = 20;
121 * memcpy(xbe.xbe_magic, MIPS64_ELF_MAGIC, xbe.xbe_msize);
122 * memcpy(xbe.xbe_mask, MIPS64_ELF_MASK, xbe.xbe_msize);
123 * sysctlbyname(IBE_SYSCTL_NAME_ADD, NULL, NULL, &xbe, sizeof(xbe));
124 *
125 * // Disable (OR Enable OR Remove) image activator for LLVM byte code
126 * bzero(&xbe, sizeof(xbe));
127 * xbe.xbe_version = IBE_VERSION;
128 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX);
129 * error = sysctlbyname(IBE_SYSCTL_NAME_DISABLE, NULL, NULL, &xbe, sizeof(xbe));
130 * // OR sysctlbyname(IBE_SYSCTL_NAME_ENABLE, NULL, NULL, &xbe, sizeof(xbe));
131 * // OR sysctlbyname(IBE_SYSCTL_NAME_REMOVE, NULL, NULL, &xbe, sizeof(xbe));
132 *
133 * // Lookup image activator  "llvm_bc"
134 * bzero(&xbe, sizeof(xbe));
135 * xbe.xbe_version = IBE_VERSION;
136 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX);
137 * size = sizeof(out_xbe);
138 * error = sysctlbyname(IBE_SYSCTL_NAME_LOOKUP, &out_xbe, &size, &xbe,
139 *	sizeof(xbe));
140 *
141 * // Get all the currently configured image activators and report
142 * error = sysctlbyname(IBE_SYSCTL_NAME_LIST, NULL, &size, NULL, 0);
143 * if (0 == error && size > 0) {
144 *	xbep = malloc(size);
145 *	while(1) {
146 *	    osize = size;
147 *	    error = sysctlbyname("kern.binmisc.list", xbep, &size, NULL, 0);
148 *	    if (-1 == error && ENOMEM == errno && size == osize) {
149 *		// The buffer too small and needs to grow
150 *		size += sizeof(xbe);
151 *		xbep = realloc(xbep, size);
152 *	    } else
153 *		break;
154 *	}
155 * }
156 * for(i = 0; i < (size / sizeof(xbe)); i++, xbep++)
157 *	printf("name: %s interpreter: %s flags: %s %s\n", xbep->xbe_name,
158 *	    xbep->xbe_interpreter, (xbep->xbe_flags & IBF_ENABLED) ?
159 *	    "ENABLED" : "", (xbep->xbe_flags & IBF_ENABLED) ? "USE_MASK" : "");
160 *
161 * The sysctlbyname() calls above may return the following errors in addition
162 * to the standard ones:
163 *
164 * [EINVAL]  Invalid argument in the input ximgact_binmisc_entry_t structure.
165 * [EEXIST]  Interpreter entry for given name already exist in kernel list.
166 * [ENOMEM]  Allocating memory in the kernel failed or, in the case of
167 *           kern.binmisc.list, the user buffer is too small.
168 * [ENOENT]  Interpreter entry for given name is not found.
169 * [ENOSPC]  Attempted to exceed maximum number of entries (IBE_MAX_ENTRIES).
170 */
171
172#endif /* !_IMGACT_BINMISC_H_ */
173