1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2013 Stacey D. Son 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 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 arguments separated 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 /* We only map the first page for identification purposes. */ 49 #define IBE_MATCH_MAX PAGE_SIZE 50 _Static_assert(IBE_MAGIC_MAX <= IBE_MATCH_MAX, 51 "Cannot identify binaries past the first page."); 52 53 /* 54 * Imgact bin misc interpreter entry flags. 55 */ 56 #define IBF_ENABLED 0x0001 /* Entry is active. */ 57 #define IBF_USE_MASK 0x0002 /* Use mask on header magic field. */ 58 #define IBF_PRE_OPEN 0x0004 /* Cache the vnode for interpreter */ 59 60 #define IBF_VALID_UFLAGS 0x0007 /* Bits allowed from userland. */ 61 62 /* 63 * Used with sysctlbyname() to pass imgact bin misc entries in and out of the 64 * kernel. 65 */ 66 typedef struct ximgact_binmisc_entry { 67 uint32_t xbe_version; /* Struct version(IBE_VERSION) */ 68 uint32_t xbe_flags; /* Entry flags (IBF_*) */ 69 uint32_t xbe_moffset; /* Magic offset in header */ 70 uint32_t xbe_msize; /* Magic size */ 71 uint32_t spare[3]; /* Spare fields for future use */ 72 char xbe_name[IBE_NAME_MAX]; /* Unique interpreter name */ 73 char xbe_interpreter[IBE_INTERP_LEN_MAX]; /* Interpreter path + args */ 74 uint8_t xbe_magic[IBE_MAGIC_MAX]; /* Header Magic */ 75 uint8_t xbe_mask[IBE_MAGIC_MAX]; /* Magic Mask */ 76 } ximgact_binmisc_entry_t; 77 78 /* 79 * sysctl() command names. 80 */ 81 #define IBE_SYSCTL_NAME "kern.binmisc" 82 83 #define IBE_SYSCTL_NAME_ADD IBE_SYSCTL_NAME ".add" 84 #define IBE_SYSCTL_NAME_REMOVE IBE_SYSCTL_NAME ".remove" 85 #define IBE_SYSCTL_NAME_DISABLE IBE_SYSCTL_NAME ".disable" 86 #define IBE_SYSCTL_NAME_ENABLE IBE_SYSCTL_NAME ".enable" 87 #define IBE_SYSCTL_NAME_LOOKUP IBE_SYSCTL_NAME ".lookup" 88 #define IBE_SYSCTL_NAME_LIST IBE_SYSCTL_NAME ".list" 89 90 #define KMOD_NAME "imgact_binmisc" 91 92 /* 93 * Examples of manipulating the interpreter table using sysctlbyname(3): 94 * 95 * #include <sys/imgact_binmisc.h> 96 * 97 * #define LLVM_MAGIC "BC\xc0\xde" 98 * 99 * #define MIPS64_ELF_MAGIC "\x7f\x45\x4c\x46\x02\x02\x01\x00\x00\x00" \ 100 * "\x00\x00\x00\x00\x00\x00\x00\x02\x00\x08" 101 * #define MIPS64_ELF_MASK "\xff\xff\xff\xff\xff\xff\xff\x00\xff\xff" \ 102 * "\xff\xff\xff\xff\xff\xff\xff\xfe\xff\xff" 103 * 104 * ximgact_binmisc_entry_t xbe, *xbep, out_xbe; 105 * size_t size = 0, osize; 106 * int error, i; 107 * 108 * // Add image activator for LLVM byte code 109 * bzero(&xbe, sizeof(xbe)); 110 * xbe.xbe_version = IBE_VERSION; 111 * xbe.xbe_flags = IBF_ENABLED; 112 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX); 113 * strlcpy(xbe.xbe_interpreter, "/usr/bin/lli --fake-arg0=#a", 114 * IBE_INTERP_LEN_MAX); 115 * xbe.xbe_moffset = 0; 116 * xbe.xbe_msize = 4; 117 * memcpy(xbe.xbe_magic, LLVM_MAGIC, xbe.xbe_msize); 118 * error = sysctlbyname(IBE_SYSCTL_NAME_ADD, NULL, NULL, &xbe, sizeof(xbe)); 119 * 120 * // Add image activator for mips64 ELF binaries to use qemu user mode 121 * bzero(&xbe, sizeof(xbe)); 122 * xbe.xbe_version = IBE_VERSION; 123 * xbe.xbe_flags = IBF_ENABLED | IBF_USE_MASK; 124 * strlcpy(xbe.xbe_name, "mips64elf", IBE_NAME_MAX); 125 * strlcpy(xbe.xbe_interpreter, "/usr/local/bin/qemu-mips64", 126 * IBE_INTERP_LEN_MAX); 127 * xbe.xbe_moffset = 0; 128 * xbe.xbe_msize = 20; 129 * memcpy(xbe.xbe_magic, MIPS64_ELF_MAGIC, xbe.xbe_msize); 130 * memcpy(xbe.xbe_mask, MIPS64_ELF_MASK, xbe.xbe_msize); 131 * sysctlbyname(IBE_SYSCTL_NAME_ADD, NULL, NULL, &xbe, sizeof(xbe)); 132 * 133 * // Disable (OR Enable OR Remove) image activator for LLVM byte code 134 * bzero(&xbe, sizeof(xbe)); 135 * xbe.xbe_version = IBE_VERSION; 136 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX); 137 * error = sysctlbyname(IBE_SYSCTL_NAME_DISABLE, NULL, NULL, &xbe, sizeof(xbe)); 138 * // OR sysctlbyname(IBE_SYSCTL_NAME_ENABLE, NULL, NULL, &xbe, sizeof(xbe)); 139 * // OR sysctlbyname(IBE_SYSCTL_NAME_REMOVE, NULL, NULL, &xbe, sizeof(xbe)); 140 * 141 * // Lookup image activator "llvm_bc" 142 * bzero(&xbe, sizeof(xbe)); 143 * xbe.xbe_version = IBE_VERSION; 144 * strlcpy(xbe.xbe_name, "llvm_bc", IBE_NAME_MAX); 145 * size = sizeof(out_xbe); 146 * error = sysctlbyname(IBE_SYSCTL_NAME_LOOKUP, &out_xbe, &size, &xbe, 147 * sizeof(xbe)); 148 * 149 * // Get all the currently configured image activators and report 150 * error = sysctlbyname(IBE_SYSCTL_NAME_LIST, NULL, &size, NULL, 0); 151 * if (0 == error && size > 0) { 152 * xbep = malloc(size); 153 * while(1) { 154 * osize = size; 155 * error = sysctlbyname("kern.binmisc.list", xbep, &size, NULL, 0); 156 * if (-1 == error && ENOMEM == errno && size == osize) { 157 * // The buffer too small and needs to grow 158 * size += sizeof(xbe); 159 * xbep = realloc(xbep, size); 160 * } else 161 * break; 162 * } 163 * } 164 * for(i = 0; i < (size / sizeof(xbe)); i++, xbep++) 165 * printf("name: %s interpreter: %s flags: %s %s\n", xbep->xbe_name, 166 * xbep->xbe_interpreter, (xbep->xbe_flags & IBF_ENABLED) ? 167 * "ENABLED" : "", (xbep->xbe_flags & IBF_ENABLED) ? "USE_MASK" : ""); 168 * 169 * The sysctlbyname() calls above may return the following errors in addition 170 * to the standard ones: 171 * 172 * [EINVAL] Invalid argument in the input ximgact_binmisc_entry_t structure. 173 * [EEXIST] Interpreter entry for given name already exist in kernel list. 174 * [ENOMEM] Allocating memory in the kernel failed or, in the case of 175 * kern.binmisc.list, the user buffer is too small. 176 * [ENOENT] Interpreter entry for given name is not found. 177 * [ENOSPC] Attempted to exceed maximum number of entries (IBE_MAX_ENTRIES). 178 */ 179 180 #endif /* !_IMGACT_BINMISC_H_ */ 181