| 1 | /* |
| 2 | * SPDX-License-Identifier: GPL-2.0-or-later |
| 3 | * |
| 4 | * uefi vars device - serialize non-volatile varstore from/to json, |
| 5 | * using qapi |
| 6 | * |
| 7 | * tools which can read/write these json files: |
| 8 | * - https://gitlab.com/kraxel/virt-firmware |
| 9 | * - https://github.com/awslabs/python-uefivars |
| 10 | */ |
| 11 | #include "qemu/osdep.h" |
| 12 | #include "qemu/cutils.h" |
| 13 | #include "qemu/error-report.h" |
| 14 | #include "system/dma.h" |
| 15 | |
| 16 | #include "hw/uefi/var-service.h" |
| 17 | |
| 18 | #include "qobject/qobject.h" |
| 19 | #include "qobject/qjson.h" |
| 20 | |
| 21 | #include "qapi/error.h" |
| 22 | #include "qapi/dealloc-visitor.h" |
| 23 | #include "qapi/qobject-input-visitor.h" |
| 24 | #include "qapi/qobject-output-visitor.h" |
| 25 | #include "qapi/qapi-types-uefi.h" |
| 26 | #include "qapi/qapi-visit-uefi.h" |
| 27 | |
| 28 | static char *generate_hexstr(void *data, size_t len) |
| 29 | { |
| 30 | static const char hex[] = { |
| 31 | '0', '1', '2', '3', '4', '5', '6', '7', |
| 32 | '8', '9', 'a', 'b', 'c', 'd', 'e', 'f', |
| 33 | }; |
| 34 | uint8_t *src = data; |
| 35 | char *dest; |
| 36 | size_t i; |
| 37 | |
| 38 | dest = g_malloc(len * 2 + 1); |
| 39 | for (i = 0; i < len * 2;) { |
| 40 | dest[i++] = hex[*src >> 4]; |
| 41 | dest[i++] = hex[*src & 15]; |
| 42 | src++; |
| 43 | } |
| 44 | dest[i++] = 0; |
| 45 | |
| 46 | return dest; |
| 47 | } |
| 48 | |
| 49 | static UefiVarStore *uefi_vars_to_qapi(uefi_vars_state *uv) |
| 50 | { |
| 51 | UefiVarStore *vs; |
| 52 | UefiVariableList **tail; |
| 53 | UefiVariable *v; |
| 54 | QemuUUID be; |
| 55 | uefi_variable *var; |
| 56 | |
| 57 | vs = g_new0(UefiVarStore, 1); |
| 58 | vs->version = 2; |
| 59 | tail = &vs->variables; |
| 60 | |
| 61 | QTAILQ_FOREACH(var, &uv->variables, next) { |
| 62 | if (!(var->attributes & EFI_VARIABLE_NON_VOLATILE)) { |
| 63 | continue; |
| 64 | } |
| 65 | |
| 66 | v = g_new0(UefiVariable, 1); |
| 67 | be = qemu_uuid_bswap(var->guid); |
| 68 | v->guid = qemu_uuid_unparse_strdup(&be); |
| 69 | v->name = uefi_ucs2_to_ascii(var->name, var->name_size); |
| 70 | v->attr = var->attributes; |
| 71 | |
| 72 | v->data = generate_hexstr(var->data, var->data_size); |
| 73 | |
| 74 | if (var->attributes & |
| 75 | EFI_VARIABLE_TIME_BASED_AUTHENTICATED_WRITE_ACCESS) { |
| 76 | v->time = generate_hexstr(&var->time, sizeof(var->time)); |
| 77 | if (var->digest && var->digest_size) { |
| 78 | v->digest = generate_hexstr(var->digest, var->digest_size); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | QAPI_LIST_APPEND(tail, v); |
| 83 | } |
| 84 | return vs; |
| 85 | } |
| 86 | |
| 87 | static unsigned parse_hexchar(char c) |
| 88 | { |
| 89 | switch (c) { |
| 90 | case '0' ... '9': return c - '0'; |
| 91 | case 'a' ... 'f': return c - 'a' + 0xa; |
| 92 | case 'A' ... 'F': return c - 'A' + 0xA; |
| 93 | default: return 0; |
| 94 | } |
| 95 | } |
| 96 | |
| 97 | static void parse_hexstr(void *dest, char *src, int len) |
| 98 | { |
| 99 | uint8_t *data = dest; |
| 100 | size_t i; |
| 101 | |
| 102 | for (i = 0; i + 1 < len; i += 2) { |
| 103 | *(data++) = |
| 104 | parse_hexchar(src[i]) << 4 | |
| 105 | parse_hexchar(src[i + 1]); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | static void uefi_vars_from_qapi(uefi_vars_state *uv, UefiVarStore *vs) |
| 110 | { |
| 111 | UefiVariableList *item; |
| 112 | UefiVariable *v; |
| 113 | QemuUUID be; |
| 114 | uefi_variable *var; |
| 115 | uint8_t *data; |
| 116 | size_t i, len; |
| 117 | |
| 118 | for (item = vs->variables; item != NULL; item = item->next) { |
| 119 | v = item->value; |
| 120 | |
| 121 | var = g_new0(uefi_variable, 1); |
| 122 | var->attributes = v->attr; |
| 123 | qemu_uuid_parse(v->guid, &be); |
| 124 | var->guid = qemu_uuid_bswap(be); |
| 125 | |
| 126 | len = strlen(v->name); |
| 127 | var->name_size = len * 2 + 2; |
| 128 | var->name = g_malloc(var->name_size); |
| 129 | for (i = 0; i <= len; i++) { |
| 130 | var->name[i] = v->name[i]; |
| 131 | } |
| 132 | |
| 133 | len = strlen(v->data); |
| 134 | var->data_size = len / 2; |
| 135 | var->data = data = g_malloc(var->data_size); |
| 136 | parse_hexstr(var->data, v->data, len); |
| 137 | |
| 138 | if (v->time && strlen(v->time) == 32) { |
| 139 | parse_hexstr(&var->time, v->time, 32); |
| 140 | } |
| 141 | |
| 142 | if (v->digest) { |
| 143 | len = strlen(v->digest); |
| 144 | var->digest_size = len / 2; |
| 145 | var->digest = g_malloc(var->digest_size); |
| 146 | parse_hexstr(var->digest, v->digest, len); |
| 147 | } |
| 148 | |
| 149 | QTAILQ_INSERT_TAIL(&uv->variables, var, next); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | static GString *uefi_vars_to_json(uefi_vars_state *uv) |
| 154 | { |
| 155 | UefiVarStore *vs = uefi_vars_to_qapi(uv); |
| 156 | QObject *qobj = NULL; |
| 157 | Visitor *v; |
| 158 | GString *gstr; |
| 159 | |
| 160 | v = qobject_output_visitor_new(&qobj); |
| 161 | if (visit_type_UefiVarStore(v, NULL, &vs, NULL)) { |
| 162 | visit_complete(v, &qobj); |
| 163 | } |
| 164 | visit_free(v); |
| 165 | qapi_free_UefiVarStore(vs); |
| 166 | |
| 167 | gstr = qobject_to_json_pretty(qobj, true); |
| 168 | qobject_unref(qobj); |
| 169 | |
| 170 | return gstr; |
| 171 | } |
| 172 | |
| 173 | void uefi_vars_json_init(uefi_vars_state *uv, Error **errp) |
| 174 | { |
| 175 | if (uv->jsonfile) { |
| 176 | uv->jsonfd = qemu_create(uv->jsonfile, O_RDWR | O_BINARY, 0666, errp); |
| 177 | } |
| 178 | } |
| 179 | |
| 180 | void uefi_vars_json_save(uefi_vars_state *uv) |
| 181 | { |
| 182 | g_autoptr(GString) gstr = NULL; |
| 183 | int rc; |
| 184 | |
| 185 | if (uv->jsonfd == -1) { |
| 186 | return; |
| 187 | } |
| 188 | |
| 189 | gstr = uefi_vars_to_json(uv); |
| 190 | |
| 191 | rc = lseek(uv->jsonfd, 0, SEEK_SET); |
| 192 | if (rc < 0) { |
| 193 | warn_report("%s: lseek error", __func__); |
| 194 | return; |
| 195 | } |
| 196 | |
| 197 | rc = ftruncate(uv->jsonfd, 0); |
| 198 | if (rc != 0) { |
| 199 | warn_report("%s: ftruncate error", __func__); |
| 200 | return; |
| 201 | } |
| 202 | |
| 203 | rc = write(uv->jsonfd, gstr->str, gstr->len); |
| 204 | if (rc != gstr->len) { |
| 205 | warn_report("%s: write error", __func__); |
| 206 | return; |
| 207 | } |
| 208 | |
| 209 | fsync(uv->jsonfd); |
| 210 | } |
| 211 | |
| 212 | void uefi_vars_json_load(uefi_vars_state *uv, Error **errp) |
| 213 | { |
| 214 | UefiVarStore *vs; |
| 215 | QObject *qobj; |
| 216 | Visitor *v; |
| 217 | char *str; |
| 218 | ssize_t len; |
| 219 | int rc; |
| 220 | |
| 221 | if (uv->jsonfd == -1) { |
| 222 | return; |
| 223 | } |
| 224 | |
| 225 | len = lseek(uv->jsonfd, 0, SEEK_END); |
| 226 | if (len < 0) { |
| 227 | warn_report("%s: lseek error", __func__); |
| 228 | return; |
| 229 | } |
| 230 | if (len == 0) { |
| 231 | /* empty file */ |
| 232 | return; |
| 233 | } |
| 234 | |
| 235 | str = g_malloc(len + 1); |
| 236 | lseek(uv->jsonfd, 0, SEEK_SET); |
| 237 | rc = read(uv->jsonfd, str, len); |
| 238 | if (rc != len) { |
| 239 | warn_report("%s: read error", __func__); |
| 240 | g_free(str); |
| 241 | return; |
| 242 | } |
| 243 | str[len] = 0; |
| 244 | |
| 245 | qobj = qobject_from_json(str, errp); |
| 246 | v = qobject_input_visitor_new(qobj); |
| 247 | visit_type_UefiVarStore(v, NULL, &vs, errp); |
| 248 | visit_free(v); |
| 249 | |
| 250 | if (!(*errp)) { |
| 251 | uefi_vars_from_qapi(uv, vs); |
| 252 | uefi_vars_update_storage(uv); |
| 253 | if (uv->used_storage > uv->max_storage) { |
| 254 | error_setg(errp, "out of variable memory (%" PRId64 " > %" PRId64 ")", |
| 255 | uv->used_storage, uv->max_storage); |
| 256 | } |
| 257 | } |
| 258 | |
| 259 | qapi_free_UefiVarStore(vs); |
| 260 | qobject_unref(qobj); |
| 261 | g_free(str); |
| 262 | } |