/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2013 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <unistd.h> #include <string.h> #include <fcntl.h> #include <ctype.h> #include "util.h" #include "utf8.h" #include "efivars.h" #ifdef ENABLE_EFI bool is_efi_boot(void) { return access("/sys/firmware/efi", F_OK) >= 0; } static int read_flag(const char *varname) { int r; void *v; size_t s; uint8_t b; r = efi_get_variable(EFI_VENDOR_GLOBAL, varname, NULL, &v, &s); if (r < 0) return r; if (s != 1) { r = -EINVAL; goto finish; } b = *(uint8_t *)v; r = b > 0; finish: free(v); return r; } int is_efi_secure_boot(void) { return read_flag("SecureBoot"); } int is_efi_secure_boot_setup_mode(void) { return read_flag("SetupMode"); } int efi_get_variable( sd_id128_t vendor, const char *name, uint32_t *attribute, void **value, size_t *size) { _cleanup_close_ int fd = -1; _cleanup_free_ char *p = NULL; uint32_t a; ssize_t n; struct stat st; void *r; assert(name); assert(value); assert(size); if (asprintf(&p, "/sys/firmware/efi/efivars/%s-%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", name, SD_ID128_FORMAT_VAL(vendor)) < 0) return -ENOMEM; fd = open(p, O_RDONLY|O_NOCTTY|O_CLOEXEC); if (fd < 0) return -errno; if (fstat(fd, &st) < 0) return -errno; if (st.st_size < 4) return -EIO; if (st.st_size > 4*1024*1024 + 4) return -E2BIG; n = read(fd, &a, sizeof(a)); if (n < 0) return -errno; if (n != sizeof(a)) return -EIO; r = malloc(st.st_size - 4 + 2); if (!r) return -ENOMEM; n = read(fd, r, (size_t) st.st_size - 4); if (n < 0) { free(r); return -errno; } if (n != (ssize_t) st.st_size - 4) { free(r); return -EIO; } /* Always NUL terminate (2 bytes, to protect UTF-16) */ ((char*) r)[st.st_size - 4] = 0; ((char*) r)[st.st_size - 4 + 1] = 0; *value = r; *size = (size_t) st.st_size - 4; if (attribute) *attribute = a; return 0; } int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) { _cleanup_free_ void *s = NULL; size_t ss; int r; char *x; r = efi_get_variable(vendor, name, NULL, &s, &ss); if (r < 0) return r; x = utf16_to_utf8(s, ss); if (!x) return -ENOMEM; *p = x; return 0; } static size_t utf16_size(const uint16_t *s) { size_t l = 0; while (s[l] > 0) l++; return (l+1) * sizeof(uint16_t); } static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) { struct uuid { uint32_t u1; uint16_t u2; uint16_t u3; uint8_t u4[8]; } _packed_; const struct uuid *uuid = guid; id128->bytes[0] = (uuid->u1 >> 24) & 0xff; id128->bytes[1] = (uuid->u1 >> 16) & 0xff; id128->bytes[2] = (uuid->u1 >> 8) & 0xff; id128->bytes[3] = (uuid->u1) & 0xff; id128->bytes[4] = (uuid->u2 >> 8) & 0xff; id128->bytes[5] = (uuid->u2) & 0xff; id128->bytes[6] = (uuid->u3 >> 8) & 0xff; id128->bytes[7] = (uuid->u3) & 0xff; memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4)); } int efi_get_boot_option( uint16_t id, char **title, sd_id128_t *part_uuid, char **path) { struct boot_option { uint32_t attr; uint16_t path_len; uint16_t title[]; } _packed_; struct drive_path { uint32_t part_nr; uint64_t part_start; uint64_t part_size; char signature[16]; uint8_t mbr_type; uint8_t signature_type; } _packed_; struct device_path { uint8_t type; uint8_t sub_type; uint16_t length; union { uint16_t path[0]; struct drive_path drive; }; } _packed_; char boot_id[9]; _cleanup_free_ uint8_t *buf = NULL; size_t l; struct boot_option *header; size_t title_size; char *s = NULL; char *p = NULL; sd_id128_t p_uuid = SD_ID128_NULL; int err; snprintf(boot_id, sizeof(boot_id), "Boot%04X", id); err = efi_get_variable(EFI_VENDOR_GLOBAL, boot_id, NULL, (void **)&buf, &l); if (err < 0) return err; if (l < sizeof(struct boot_option)) return -ENOENT; header = (struct boot_option *)buf; title_size = utf16_size(header->title); if (title_size > l - offsetof(struct boot_option, title)) return -EINVAL; s = utf16_to_utf8(header->title, title_size); if (!s) { err = -ENOMEM; goto err; } if (header->path_len > 0) { uint8_t *dbuf; size_t dnext; dbuf = buf + offsetof(struct boot_option, title) + title_size; dnext = 0; while (dnext < header->path_len) { struct device_path *dpath; dpath = (struct device_path *)(dbuf + dnext); if (dpath->length < 4) break; /* Type 0x7F – End of Hardware Device Path, Sub-Type 0xFF – End Entire Device Path */ if (dpath->type == 0x7f && dpath->sub_type == 0xff) break; dnext += dpath->length; /* Type 0x04 – Media Device Path */ if (dpath->type != 0x04) continue; /* Sub-Type 1 – Hard Drive */ if (dpath->sub_type == 0x01) { /* 0x02 – GUID Partition Table */ if (dpath->drive.mbr_type != 0x02) continue; /* 0x02 – GUID signature */ if (dpath->drive.signature_type != 0x02) continue; efi_guid_to_id128(dpath->drive.signature, &p_uuid); continue; } /* Sub-Type 4 – File Path */ if (dpath->sub_type == 0x04) { p = utf16_to_utf8(dpath->path, dpath->length-4); continue; } } } if (title) *title = s; if (part_uuid) *part_uuid = p_uuid; if (path) *path = p; return 0; err: free(s); free(p); return err; } int efi_get_boot_order(uint16_t **order) { void *buf; size_t l; int r; r = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l); if (r < 0) return r; if (l <= 0) { free(buf); return -ENOENT; } if ((l % sizeof(uint16_t) > 0) || (l / sizeof(uint16_t) > INT_MAX)) { free(buf); return -EINVAL; } *order = buf; return (int) (l / sizeof(uint16_t)); } static int boot_id_hex(const char s[4]) { int i; int id = 0; for (i = 0; i < 4; i++) if (s[i] >= '0' && s[i] <= '9') id |= (s[i] - '0') << (3 - i) * 4; else if (s[i] >= 'A' && s[i] <= 'F') id |= (s[i] - 'A' + 10) << (3 - i) * 4; else return -1; return id; } static int cmp_uint16(const void *_a, const void *_b) { const uint16_t *a = _a, *b = _b; return (int)*a - (int)*b; } int efi_get_boot_options(uint16_t **options) { _cleanup_closedir_ DIR *dir = NULL; struct dirent *de; uint16_t *list = NULL; int count = 0, r; assert(options); dir = opendir("/sys/firmware/efi/efivars/"); if (!dir) return -errno; FOREACH_DIRENT(de, dir, r = -errno; goto fail) { int id; uint16_t *t; if (strncmp(de->d_name, "Boot", 4) != 0) continue; if (strlen(de->d_name) != 45) continue; if (strcmp(de->d_name + 8, "-8be4df61-93ca-11d2-aa0d-00e098032b8c") != 0) continue; id = boot_id_hex(de->d_name + 4); if (id < 0) continue; t = realloc(list, (count + 1) * sizeof(uint16_t)); if (!t) { r = -ENOMEM; goto fail; } list = t; list[count ++] = id; } qsort(list, count, sizeof(uint16_t), cmp_uint16); *options = list; return count; fail: free(list); return r; } static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) { _cleanup_free_ char *j = NULL; int r; uint64_t x; assert(name); assert(u); r = efi_get_variable_string(EFI_VENDOR_LOADER, name, &j); if (r < 0) return r; r = safe_atou64(j, &x); if (r < 0) return r; *u = x; return 0; } static int get_boot_usec(usec_t *firmware, usec_t *loader) { uint64_t x, y; int r; assert(firmware); assert(loader); r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeInitUSec", &x); if (r < 0) return r; r = read_usec(EFI_VENDOR_LOADER, "LoaderTimeExecUSec", &y); if (r < 0) return r; if (y == 0 || y < x) return -EIO; if (y > USEC_PER_HOUR) return -EIO; *firmware = x; *loader = y; return 0; } int efi_get_boot_timestamps(const dual_timestamp *n, dual_timestamp *firmware, dual_timestamp *loader) { usec_t x, y, a; int r; dual_timestamp _n; assert(firmware); assert(loader); if (!n) { dual_timestamp_get(&_n); n = &_n; } r = get_boot_usec(&x, &y); if (r < 0) return r; /* Let's convert this to timestamps where the firmware * began/loader began working. To make this more confusing: * since usec_t is unsigned and the kernel's monotonic clock * begins at kernel initialization we'll actually initialize * the monotonic timestamps here as negative of the actual * value. */ firmware->monotonic = y; loader->monotonic = y - x; a = n->monotonic + firmware->monotonic; firmware->realtime = n->realtime > a ? n->realtime - a : 0; a = n->monotonic + loader->monotonic; loader->realtime = n->realtime > a ? n->realtime - a : 0; return 0; } int efi_get_loader_device_part_uuid(sd_id128_t *u) { _cleanup_free_ char *p = NULL; int r, parsed[16]; unsigned i; assert(u); r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", &p); if (r < 0) return r; if (sscanf(p, "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x", &parsed[0], &parsed[1], &parsed[2], &parsed[3], &parsed[4], &parsed[5], &parsed[6], &parsed[7], &parsed[8], &parsed[9], &parsed[10], &parsed[11], &parsed[12], &parsed[13], &parsed[14], &parsed[15]) != 16) return -EIO; for (i = 0; i < ELEMENTSOF(parsed); i++) u->bytes[i] = parsed[i]; return 0; } #endif