1 /* 2 * Copyright (c) 2014, STMicroelectronics International N.V. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 16 * AND 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 COPYRIGHT HOLDER OR CONTRIBUTORS BE 19 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <string.h> 29 #include <stdlib.h> 30 #include <trace.h> 31 #include <utee_defines.h> 32 #include <kernel/tee_time.h> 33 34 struct tee_ta_time_offs { 35 TEE_UUID uuid; 36 TEE_Time offs; 37 bool positive; 38 }; 39 40 static struct tee_ta_time_offs *tee_time_offs; 41 static size_t tee_time_num_offs; 42 43 static TEE_Result tee_time_ta_get_offs(const TEE_UUID *uuid, 44 const TEE_Time **offs, bool *positive) 45 { 46 size_t n; 47 48 for (n = 0; n < tee_time_num_offs; n++) { 49 if (memcmp(uuid, &tee_time_offs[n].uuid, sizeof(TEE_UUID)) 50 == 0) { 51 *offs = &tee_time_offs[n].offs; 52 *positive = tee_time_offs[n].positive; 53 return TEE_SUCCESS; 54 } 55 } 56 return TEE_ERROR_TIME_NOT_SET; 57 } 58 59 static TEE_Result tee_time_ta_set_offs(const TEE_UUID *uuid, 60 const TEE_Time *offs, bool positive) 61 { 62 size_t n; 63 struct tee_ta_time_offs *o; 64 65 for (n = 0; n < tee_time_num_offs; n++) { 66 if (memcmp(uuid, &tee_time_offs[n].uuid, sizeof(TEE_UUID)) 67 == 0) { 68 tee_time_offs[n].offs = *offs; 69 tee_time_offs[n].positive = positive; 70 return TEE_SUCCESS; 71 } 72 } 73 74 n = tee_time_num_offs + 1; 75 o = malloc(n * sizeof(struct tee_ta_time_offs)); 76 if (o == NULL) 77 return TEE_ERROR_OUT_OF_MEMORY; 78 memcpy(o, tee_time_offs, 79 tee_time_num_offs * sizeof(struct tee_ta_time_offs)); 80 free(tee_time_offs); 81 tee_time_offs = o; 82 tee_time_offs[tee_time_num_offs].uuid = *uuid; 83 tee_time_offs[tee_time_num_offs].offs = *offs; 84 tee_time_offs[tee_time_num_offs].positive = positive; 85 tee_time_num_offs = n; 86 return TEE_SUCCESS; 87 } 88 89 TEE_Result tee_time_get_ta_time(const TEE_UUID *uuid, TEE_Time *time) 90 { 91 TEE_Result res; 92 const TEE_Time *offs; 93 bool positive; 94 TEE_Time t; 95 TEE_Time t2; 96 97 res = tee_time_ta_get_offs(uuid, &offs, &positive); 98 if (res != TEE_SUCCESS) 99 return res; 100 101 res = tee_time_get_sys_time(&t); 102 if (res != TEE_SUCCESS) 103 return res; 104 105 if (positive) { 106 TEE_TIME_ADD(t, *offs, t2); 107 108 /* Detect wrapping, the wrapped time should be returned. */ 109 if (TEE_TIME_LT(t2, t)) 110 res = TEE_ERROR_OVERFLOW; 111 } else { 112 TEE_TIME_SUB(t, *offs, t2); 113 114 /* Detect wrapping, the wrapped time should be returned. */ 115 if (TEE_TIME_LE(t, t2)) 116 res = TEE_ERROR_OVERFLOW; 117 } 118 *time = t2; 119 120 return res; 121 } 122 123 TEE_Result tee_time_set_ta_time(const TEE_UUID *uuid, const TEE_Time *time) 124 { 125 TEE_Result res; 126 TEE_Time offs; 127 TEE_Time t; 128 129 /* Check that time is normalized. */ 130 if (time->millis >= TEE_TIME_MILLIS_BASE) 131 return TEE_ERROR_BAD_PARAMETERS; 132 133 res = tee_time_get_sys_time(&t); 134 if (res != TEE_SUCCESS) 135 return res; 136 137 if (TEE_TIME_LT(t, *time)) { 138 TEE_TIME_SUB(*time, t, offs); 139 return tee_time_ta_set_offs(uuid, &offs, true); 140 } else { 141 TEE_TIME_SUB(t, *time, offs); 142 return tee_time_ta_set_offs(uuid, &offs, false); 143 } 144 } 145