chiark / gitweb /
systemd-detect-virt: detect s390 virtualization
[elogind.git] / src / shared / efivars.c
index e16c61029ba65c982f9290965f1a4ee327cf3747..f18f5c4b16aa4b81057c5e2cbb96f0968f26e1a8 100644 (file)
 #include <unistd.h>
 #include <string.h>
 #include <fcntl.h>
+#include <ctype.h>
 
+#include "acpi-fpdt.h"
 #include "util.h"
 #include "utf8.h"
 #include "efivars.h"
 
-bool is_efiboot(void) {
+#ifdef ENABLE_EFI
+
+bool is_efi_boot(void) {
         return access("/sys/firmware/efi", F_OK) >= 0;
 }
 
-int efi_get_variable(sd_id128_t vendor, const char *name, uint32_t *attribute, void **value, size_t *size) {
+static int read_flag(const char *varname) {
+        int r;
+        _cleanup_free_ void *v = NULL;
+        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)
+                return -EINVAL;
+
+        b = *(uint8_t *)v;
+        r = b > 0;
+        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;
@@ -61,7 +97,7 @@ int efi_get_variable(sd_id128_t vendor, const char *name, uint32_t *attribute, v
 
         n = read(fd, &a, sizeof(a));
         if (n < 0)
-                return (int) n;
+                return -errno;
         if (n != sizeof(a))
                 return -EIO;
 
@@ -72,7 +108,7 @@ int efi_get_variable(sd_id128_t vendor, const char *name, uint32_t *attribute, v
         n = read(fd, r, (size_t) st.st_size - 4);
         if (n < 0) {
                 free(r);
-                return (int) -n;
+                return -errno;
         }
         if (n != (ssize_t) st.st_size - 4) {
                 free(r);
@@ -92,15 +128,22 @@ int efi_get_variable(sd_id128_t vendor, const char *name, uint32_t *attribute, v
         return 0;
 }
 
-char *efi_get_variable_string(sd_id128_t vendor, const char *name) {
+int efi_get_variable_string(sd_id128_t vendor, const char *name, char **p) {
         _cleanup_free_ void *s = NULL;
-        size_t ss;
-        int err;
+        size_t ss = 0;
+        int r;
+        char *x;
 
-        err = efi_get_variable(vendor, name, NULL, &s, &ss);
-        if (err < 0)
-                return NULL;
-        return utf16_to_utf8(s, ss);
+        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) {
@@ -108,6 +151,7 @@ static size_t utf16_size(const uint16_t *s) {
 
         while (s[l] > 0)
                 l++;
+
         return (l+1) * sizeof(uint16_t);
 }
 
@@ -131,7 +175,12 @@ static void efi_guid_to_id128(const void *guid, sd_id128_t *id128) {
         memcpy(&id128->bytes[8], uuid->u4, sizeof(uuid->u4));
 }
 
-int efi_get_boot_option(uint32_t id, uint32_t *attributes, char **title, sd_id128_t *part_uuid, char **path, char **data, size_t *data_size) {
+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;
@@ -157,23 +206,20 @@ int efi_get_boot_option(uint32_t id, uint32_t *attributes, char **title, sd_id12
                 };
         } _packed_;
 
-        char boot_id[32];
-        _cleanup_free_ char *buf = NULL;
+        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;
-        char *d = NULL;
-        size_t d_size = 0;
         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;
 
@@ -182,14 +228,16 @@ int efi_get_boot_option(uint32_t id, uint32_t *attributes, char **title, sd_id12
         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 (title) {
+                s = utf16_to_utf8(header->title, title_size);
+                if (!s) {
+                        err = -ENOMEM;
+                        goto err;
+                }
         }
 
         if (header->path_len > 0) {
-                char *dbuf;
+                uint8_t *dbuf;
                 size_t dnext;
 
                 dbuf = buf + offsetof(struct boot_option, title) + title_size;
@@ -221,77 +269,139 @@ int efi_get_boot_option(uint32_t id, uint32_t *attributes, char **title, sd_id12
                                 if (dpath->drive.signature_type != 0x02)
                                         continue;
 
-                                efi_guid_to_id128(dpath->drive.signature, &p_uuid);
+                                if (part_uuid)
+                                        efi_guid_to_id128(dpath->drive.signature, &p_uuid);
                                 continue;
                         }
 
                         /* Sub-Type 4 – File Path */
-                        if (dpath->sub_type == 0x04) {
+                        if (dpath->sub_type == 0x04 && !p && path) {
                                 p = utf16_to_utf8(dpath->path, dpath->length-4);
                                 continue;
                         }
                 }
         }
 
-        *title = s;
+        if (title)
+                *title = s;
         if (part_uuid)
                 *part_uuid = p_uuid;
         if (path)
                 *path = p;
-        if (data)
-                *data = d;
-        if (data_size)
-                *data_size = d_size;
+
         return 0;
 err:
         free(s);
         free(p);
-        free(d);
         return err;
 }
 
-int efi_get_boot_order(uint16_t **order, size_t *count) {
+int efi_get_boot_order(uint16_t **order) {
         void *buf;
         size_t l;
-        int err;
+        int r;
 
-        err = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l);
-        if (err < 0)
-                return err;
+        r = efi_get_variable(EFI_VENDOR_GLOBAL, "BootOrder", NULL, &buf, &l);
+        if (r < 0)
+                return r;
 
-        if (l == 0) {
+        if (l <= 0) {
                 free(buf);
                 return -ENOENT;
         }
 
-        if ((l % sizeof(uint16_t) > 0)) {
+        if ((l % sizeof(uint16_t) > 0) ||
+            (l / sizeof(uint16_t) > INT_MAX)) {
                 free(buf);
                 return -EINVAL;
         }
 
         *order = buf;
-        *count = l / sizeof(uint16_t);
-        return 0;
+        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_safe(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_ void *i = NULL;
         _cleanup_free_ char *j = NULL;
-        size_t is;
         int r;
-        uint64_t x;
+        uint64_t x = 0;
 
         assert(name);
         assert(u);
 
-        r = efi_get_variable(EFI_VENDOR_LOADER, name, NULL, &i, &is);
+        r = efi_get_variable_string(EFI_VENDOR_LOADER, name, &j);
         if (r < 0)
                 return r;
 
-        j = utf16_to_utf8(i, is);
-        if (!j)
-                return -ENOMEM;
-
         r = safe_atou64(j, &x);
         if (r < 0)
                 return r;
@@ -300,7 +410,7 @@ static int read_usec(sd_id128_t vendor, const char *name, usec_t *u) {
         return 0;
 }
 
-static int get_boot_usec(usec_t *firmware, usec_t *loader) {
+int efi_loader_get_boot_usec(usec_t *firmware, usec_t *loader) {
         uint64_t x, y;
         int r;
 
@@ -327,59 +437,14 @@ static int get_boot_usec(usec_t *firmware, usec_t *loader) {
         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_ void *s = NULL;
+int efi_loader_get_device_part_uuid(sd_id128_t *u) {
         _cleanup_free_ char *p = NULL;
-        size_t ss;
         int r, parsed[16];
-        unsigned i;
-
-        assert(u);
 
-        r = efi_get_variable(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", NULL, &s, &ss);
+        r = efi_get_variable_string(EFI_VENDOR_LOADER, "LoaderDevicePartUUID", &p);
         if (r < 0)
                 return r;
 
-        p = utf16_to_utf8(s, ss);
-        if (!p)
-                return -ENOMEM;
-
         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],
@@ -387,8 +452,14 @@ int efi_get_loader_device_part_uuid(sd_id128_t *u) {
                    &parsed[12], &parsed[13], &parsed[14], &parsed[15]) != 16)
                 return -EIO;
 
-        for (i = 0; i < ELEMENTSOF(parsed); i++)
-                u->bytes[i] = parsed[i];
+        if (u) {
+                unsigned i;
+
+                for (i = 0; i < ELEMENTSOF(parsed); i++)
+                        u->bytes[i] = parsed[i];
+        }
 
         return 0;
 }
+
+#endif