| 1 | /* |
| 2 | * Copyright (c) 2014 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 | #include <pexpert/pexpert.h> |
| 30 | #include <sys/csr.h> |
| 31 | #include <sys/errno.h> |
| 32 | #include <sys/sysproto.h> |
| 33 | #include <sys/systm.h> |
| 34 | #include <sys/types.h> |
| 35 | |
| 36 | /* enable enforcement by default */ |
| 37 | static int csr_allow_all = 0; |
| 38 | |
| 39 | void |
| 40 | csr_init(void) |
| 41 | { |
| 42 | boot_args *args = (boot_args *)PE_state.bootArgs; |
| 43 | if (args->flags & kBootArgsFlagCSRBoot) { |
| 44 | /* special booter; allow everything */ |
| 45 | csr_allow_all = 1; |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | int |
| 50 | csr_get_active_config(csr_config_t *config) |
| 51 | { |
| 52 | boot_args *args = (boot_args *)PE_state.bootArgs; |
| 53 | if (args->flags & kBootArgsFlagCSRActiveConfig) { |
| 54 | *config = args->csrActiveConfig & CSR_VALID_FLAGS; |
| 55 | } else { |
| 56 | *config = 0; |
| 57 | } |
| 58 | |
| 59 | return 0; |
| 60 | } |
| 61 | |
| 62 | int |
| 63 | csr_check(csr_config_t mask) |
| 64 | { |
| 65 | boot_args *args = (boot_args *)PE_state.bootArgs; |
| 66 | if ((mask & CSR_ALLOW_DEVICE_CONFIGURATION) && !(args->flags & kBootArgsFlagCSRConfigMode)) |
| 67 | return EPERM; |
| 68 | |
| 69 | if (csr_allow_all) { |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | csr_config_t config; |
| 74 | int error = csr_get_active_config(&config); |
| 75 | if (error) { |
| 76 | return error; |
| 77 | } |
| 78 | |
| 79 | if (mask == 0) { |
| 80 | /* pass 0 to check if Rootless enforcement is active */ |
| 81 | return -1; |
| 82 | } |
| 83 | |
| 84 | error = (config & mask) ? 0 : EPERM; |
| 85 | return error; |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * Syscall stubs |
| 90 | */ |
| 91 | |
| 92 | int syscall_csr_check(struct csrctl_args *args); |
| 93 | int syscall_csr_get_active_config(struct csrctl_args *args); |
| 94 | |
| 95 | |
| 96 | int |
| 97 | syscall_csr_check(struct csrctl_args *args) |
| 98 | { |
| 99 | csr_config_t mask = 0; |
| 100 | int error = 0; |
| 101 | |
| 102 | if (args->useraddr == 0 || args->usersize != sizeof(mask)) |
| 103 | return EINVAL; |
| 104 | |
| 105 | error = copyin(args->useraddr, &mask, sizeof(mask)); |
| 106 | if (error) |
| 107 | return error; |
| 108 | |
| 109 | return csr_check(mask); |
| 110 | } |
| 111 | |
| 112 | int |
| 113 | syscall_csr_get_active_config(struct csrctl_args *args) |
| 114 | { |
| 115 | csr_config_t config = 0; |
| 116 | int error = 0; |
| 117 | |
| 118 | if (args->useraddr == 0 || args->usersize != sizeof(config)) |
| 119 | return EINVAL; |
| 120 | |
| 121 | error = csr_get_active_config(&config); |
| 122 | if (error) |
| 123 | return error; |
| 124 | |
| 125 | return copyout(&config, args->useraddr, sizeof(config)); |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Syscall entrypoint |
| 130 | */ |
| 131 | |
| 132 | int |
| 133 | csrctl(__unused proc_t p, struct csrctl_args *args, __unused int32_t *retval) |
| 134 | { |
| 135 | switch (args->op) { |
| 136 | case CSR_SYSCALL_CHECK: |
| 137 | return syscall_csr_check(args); |
| 138 | case CSR_SYSCALL_GET_ACTIVE_CONFIG: |
| 139 | return syscall_csr_get_active_config(args); |
| 140 | default: |
| 141 | return ENOSYS; |
| 142 | } |
| 143 | } |