Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Class and permission mappings. |
| 3 | */ |
| 4 | |
| 5 | #include <errno.h> |
| 6 | #include <stdio.h> |
| 7 | #include <stdlib.h> |
| 8 | #include <stdarg.h> |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 9 | #include <selinux/selinux.h> |
| 10 | #include <selinux/avc.h> |
| 11 | #include "mapping.h" |
| 12 | |
| 13 | /* |
| 14 | * Class and permission mappings |
| 15 | */ |
| 16 | |
| 17 | struct selinux_mapping { |
| 18 | security_class_t value; /* real, kernel value */ |
| 19 | unsigned num_perms; |
| 20 | access_vector_t perms[sizeof(access_vector_t) * 8]; |
| 21 | }; |
| 22 | |
| 23 | static struct selinux_mapping *current_mapping = NULL; |
| 24 | static security_class_t current_mapping_size = 0; |
| 25 | |
| 26 | /* |
| 27 | * Mapping setting function |
| 28 | */ |
| 29 | |
| 30 | int |
| 31 | selinux_set_mapping(struct security_class_mapping *map) |
| 32 | { |
| 33 | size_t size = sizeof(struct selinux_mapping); |
| 34 | security_class_t i, j; |
| 35 | unsigned k; |
| 36 | |
| 37 | free(current_mapping); |
| 38 | current_mapping = NULL; |
| 39 | current_mapping_size = 0; |
| 40 | |
| 41 | if (avc_reset() < 0) |
| 42 | goto err; |
| 43 | |
| 44 | /* Find number of classes in the input mapping */ |
| 45 | if (!map) { |
| 46 | errno = EINVAL; |
| 47 | goto err; |
| 48 | } |
| 49 | i = 0; |
| 50 | while (map[i].name) |
| 51 | i++; |
| 52 | |
| 53 | /* Allocate space for the class records, plus one for class zero */ |
| 54 | current_mapping = (struct selinux_mapping *)calloc(++i, size); |
| 55 | if (!current_mapping) |
| 56 | goto err; |
| 57 | |
| 58 | /* Store the raw class and permission values */ |
| 59 | j = 0; |
| 60 | while (map[j].name) { |
| 61 | struct security_class_mapping *p_in = map + (j++); |
| 62 | struct selinux_mapping *p_out = current_mapping + j; |
| 63 | |
| 64 | p_out->value = string_to_security_class(p_in->name); |
| 65 | if (!p_out->value) |
| 66 | goto err2; |
| 67 | |
| 68 | k = 0; |
Eric Paris | c01e95f | 2012-11-29 09:41:38 -0500 | [diff] [blame] | 69 | while (p_in->perms[k]) { |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 70 | /* An empty permission string skips ahead */ |
| 71 | if (!*p_in->perms[k]) { |
| 72 | k++; |
| 73 | continue; |
| 74 | } |
| 75 | p_out->perms[k] = string_to_av_perm(p_out->value, |
| 76 | p_in->perms[k]); |
| 77 | if (!p_out->perms[k]) |
| 78 | goto err2; |
| 79 | k++; |
| 80 | } |
| 81 | p_out->num_perms = k; |
| 82 | } |
| 83 | |
| 84 | /* Set the mapping size here so the above lookups are "raw" */ |
| 85 | current_mapping_size = i; |
| 86 | return 0; |
| 87 | err2: |
| 88 | free(current_mapping); |
| 89 | current_mapping = NULL; |
| 90 | current_mapping_size = 0; |
| 91 | err: |
| 92 | return -1; |
| 93 | } |
| 94 | |
| 95 | /* |
| 96 | * Get real, kernel values from mapped values |
| 97 | */ |
| 98 | |
| 99 | security_class_t |
| 100 | unmap_class(security_class_t tclass) |
| 101 | { |
| 102 | if (tclass < current_mapping_size) |
| 103 | return current_mapping[tclass].value; |
| 104 | |
Richard Haines | 574290e | 2011-03-30 17:10:05 +0100 | [diff] [blame] | 105 | /* If here no mapping set or the class requested is not valid. */ |
| 106 | if (current_mapping_size != 0) { |
| 107 | errno = EINVAL; |
| 108 | return 0; |
| 109 | } |
| 110 | else |
| 111 | return tclass; |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 112 | } |
| 113 | |
| 114 | access_vector_t |
| 115 | unmap_perm(security_class_t tclass, access_vector_t tperm) |
| 116 | { |
| 117 | if (tclass < current_mapping_size) { |
| 118 | unsigned i; |
| 119 | access_vector_t kperm = 0; |
| 120 | |
| 121 | for (i=0; i<current_mapping[tclass].num_perms; i++) |
| 122 | if (tperm & (1<<i)) { |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 123 | kperm |= current_mapping[tclass].perms[i]; |
| 124 | tperm &= ~(1<<i); |
| 125 | } |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 126 | return kperm; |
| 127 | } |
| 128 | |
Richard Haines | 574290e | 2011-03-30 17:10:05 +0100 | [diff] [blame] | 129 | /* If here no mapping set or the perm requested is not valid. */ |
| 130 | if (current_mapping_size != 0) { |
| 131 | errno = EINVAL; |
| 132 | return 0; |
| 133 | } |
| 134 | else |
| 135 | return tperm; |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 136 | } |
| 137 | |
| 138 | /* |
| 139 | * Get mapped values from real, kernel values |
| 140 | */ |
| 141 | |
| 142 | security_class_t |
| 143 | map_class(security_class_t kclass) |
| 144 | { |
| 145 | security_class_t i; |
| 146 | |
| 147 | for (i=0; i<current_mapping_size; i++) |
| 148 | if (current_mapping[i].value == kclass) |
| 149 | return i; |
| 150 | |
Richard Haines | 574290e | 2011-03-30 17:10:05 +0100 | [diff] [blame] | 151 | /* If here no mapping set or the class requested is not valid. */ |
| 152 | if (current_mapping_size != 0) { |
| 153 | errno = EINVAL; |
| 154 | return 0; |
| 155 | } |
| 156 | else |
| 157 | return kclass; |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | access_vector_t |
| 161 | map_perm(security_class_t tclass, access_vector_t kperm) |
| 162 | { |
| 163 | if (tclass < current_mapping_size) { |
| 164 | unsigned i; |
| 165 | access_vector_t tperm = 0; |
| 166 | |
| 167 | for (i=0; i<current_mapping[tclass].num_perms; i++) |
| 168 | if (kperm & current_mapping[tclass].perms[i]) { |
| 169 | tperm |= 1<<i; |
| 170 | kperm &= ~current_mapping[tclass].perms[i]; |
| 171 | } |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 172 | |
Richard Haines | 574290e | 2011-03-30 17:10:05 +0100 | [diff] [blame] | 173 | if (tperm == 0) { |
| 174 | errno = EINVAL; |
| 175 | return 0; |
| 176 | } |
| 177 | else |
| 178 | return tperm; |
| 179 | } |
Stephen Smalley | f074036 | 2012-01-04 12:30:47 -0500 | [diff] [blame] | 180 | return kperm; |
| 181 | } |
| 182 | |
| 183 | void |
| 184 | map_decision(security_class_t tclass, struct av_decision *avd) |
| 185 | { |
| 186 | if (tclass < current_mapping_size) { |
| 187 | unsigned i; |
| 188 | access_vector_t result; |
| 189 | |
| 190 | for (i=0, result=0; i<current_mapping[tclass].num_perms; i++) |
| 191 | if (avd->allowed & current_mapping[tclass].perms[i]) |
| 192 | result |= 1<<i; |
| 193 | avd->allowed = result; |
| 194 | |
| 195 | for (i=0, result=0; i<current_mapping[tclass].num_perms; i++) |
| 196 | if (avd->decided & current_mapping[tclass].perms[i]) |
| 197 | result |= 1<<i; |
| 198 | avd->decided = result; |
| 199 | |
| 200 | for (i=0, result=0; i<current_mapping[tclass].num_perms; i++) |
| 201 | if (avd->auditallow & current_mapping[tclass].perms[i]) |
| 202 | result |= 1<<i; |
| 203 | avd->auditallow = result; |
| 204 | |
| 205 | for (i=0, result=0; i<current_mapping[tclass].num_perms; i++) |
| 206 | if (avd->auditdeny & current_mapping[tclass].perms[i]) |
| 207 | result |= 1<<i; |
| 208 | avd->auditdeny = result; |
| 209 | } |
| 210 | } |