From 8399488672e8717d3aa454f9f67408f96168074f Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 26 Feb 2022 12:10:10 +0100 Subject: efi_loader: export efi_dp_shorten() Rename function shorten_path() to efi_dp_shorten() and export it. Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_device_path.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'lib/efi_loader/efi_device_path.c') diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c index dc787b4d3dd..ddd5f132ec5 100644 --- a/lib/efi_loader/efi_device_path.c +++ b/lib/efi_loader/efi_device_path.c @@ -122,20 +122,25 @@ int efi_dp_match(const struct efi_device_path *a, } } -/* +/** + * efi_dp_shorten() - shorten device-path + * * We can have device paths that start with a USB WWID or a USB Class node, * and a few other cases which don't encode the full device path with bus * hierarchy: * - * - MESSAGING:USB_WWID - * - MESSAGING:USB_CLASS - * - MEDIA:FILE_PATH - * - MEDIA:HARD_DRIVE - * - MESSAGING:URI + * * MESSAGING:USB_WWID + * * MESSAGING:USB_CLASS + * * MEDIA:FILE_PATH + * * MEDIA:HARD_DRIVE + * * MESSAGING:URI * * See UEFI spec (section 3.1.2, about short-form device-paths) + * + * @dp: original devie-path + * @Return: shortened device-path or NULL */ -static struct efi_device_path *shorten_path(struct efi_device_path *dp) +struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp) { while (dp) { /* @@ -189,7 +194,7 @@ static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path, } } - obj_dp = shorten_path(efi_dp_next(obj_dp)); + obj_dp = efi_dp_shorten(efi_dp_next(obj_dp)); } while (short_path && obj_dp); } -- cgit v1.2.3 From c409593d0853da646194b0a3d65c8b45fe7cb6d4 Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Fri, 4 Mar 2022 08:20:00 +0100 Subject: efi_loader: fix efi_dp_find_obj() efi_dp_find_obj() should not return any handle with a partially matching device path but the handle with the maximum matching device path. Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_device_path.c | 110 ++++++++++++++++++++++----------------- 1 file changed, 61 insertions(+), 49 deletions(-) (limited to 'lib/efi_loader/efi_device_path.c') diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c index ddd5f132ec5..aeb52648200 100644 --- a/lib/efi_loader/efi_device_path.c +++ b/lib/efi_loader/efi_device_path.c @@ -159,69 +159,81 @@ struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp) return dp; } -static struct efi_object *find_obj(struct efi_device_path *dp, bool short_path, - struct efi_device_path **rem) +/** + * find_handle() - find handle by device path + * + * If @rem is provided, the handle with the longest partial match is returned. + * + * @dp: device path to search + * @short_path: use short form device path for matching + * @rem: pointer to receive remaining device path + * Return: matching handle + */ +static efi_handle_t find_handle(struct efi_device_path *dp, bool short_path, + struct efi_device_path **rem) { - struct efi_object *efiobj; - efi_uintn_t dp_size = efi_dp_instance_size(dp); + efi_handle_t handle, best_handle = NULL; + efi_uintn_t len, best_len = 0; + + len = efi_dp_instance_size(dp); - list_for_each_entry(efiobj, &efi_obj_list, link) { + list_for_each_entry(handle, &efi_obj_list, link) { struct efi_handler *handler; - struct efi_device_path *obj_dp; + struct efi_device_path *dp_current; + efi_uintn_t len_current; efi_status_t ret; - ret = efi_search_protocol(efiobj, - &efi_guid_device_path, &handler); + ret = efi_search_protocol(handle, &efi_guid_device_path, + &handler); if (ret != EFI_SUCCESS) continue; - obj_dp = handler->protocol_interface; - - do { - if (efi_dp_match(dp, obj_dp) == 0) { - if (rem) { - /* - * Allow partial matches, but inform - * the caller. - */ - *rem = ((void *)dp) + - efi_dp_instance_size(obj_dp); - return efiobj; - } else { - /* Only return on exact matches */ - if (efi_dp_instance_size(obj_dp) == - dp_size) - return efiobj; - } - } - - obj_dp = efi_dp_shorten(efi_dp_next(obj_dp)); - } while (short_path && obj_dp); + dp_current = handler->protocol_interface; + if (short_path) { + dp_current = efi_dp_shorten(dp_current); + if (!dp_current) + continue; + } + len_current = efi_dp_instance_size(dp_current); + if (rem) { + if (len_current < len) + continue; + } else { + if (len_current != len) + continue; + } + if (memcmp(dp_current, dp, len)) + continue; + if (!rem) + return handle; + if (len_current > best_len) { + best_len = len_current; + best_handle = handle; + *rem = (void*)((u8 *)dp + len_current); + } } - - return NULL; + return best_handle; } -/* - * Find an efiobj from device-path, if 'rem' is not NULL, returns the - * remaining part of the device path after the matched object. +/** + * efi_dp_find_obj() - find handle by device path + * + * If @rem is provided, the handle with the longest partial match is returned. + * + * @dp: device path to search + * @rem: pointer to receive remaining device path + * Return: matching handle */ -struct efi_object *efi_dp_find_obj(struct efi_device_path *dp, - struct efi_device_path **rem) +efi_handle_t efi_dp_find_obj(struct efi_device_path *dp, + struct efi_device_path **rem) { - struct efi_object *efiobj; - - /* Search for an exact match first */ - efiobj = find_obj(dp, false, NULL); - - /* Then for a fuzzy match */ - if (!efiobj) - efiobj = find_obj(dp, false, rem); + efi_handle_t handle; - /* And now for a fuzzy short match */ - if (!efiobj) - efiobj = find_obj(dp, true, rem); + handle = find_handle(dp, false, rem); + if (!handle) + /* Match short form device path */ + handle = find_handle(dp, true, rem); - return efiobj; + return handle; } /* -- cgit v1.2.3 From e46ef1db9e2c87d5aa13a04ea2329b8bae7ea9db Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Sat, 19 Mar 2022 06:35:43 +0100 Subject: efi_loader: efi_dp_find_obj() add protocol check Let function efi_dp_find_obj() additionally check if a given protocol is installed on the handle relating to the device-path. Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_device_path.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) (limited to 'lib/efi_loader/efi_device_path.c') diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c index aeb52648200..0a8802903d7 100644 --- a/lib/efi_loader/efi_device_path.c +++ b/lib/efi_loader/efi_device_path.c @@ -160,17 +160,19 @@ struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp) } /** - * find_handle() - find handle by device path + * find_handle() - find handle by device path and installed protocol * * If @rem is provided, the handle with the longest partial match is returned. * * @dp: device path to search + * @guid: GUID of protocol that must be installed on path or NULL * @short_path: use short form device path for matching * @rem: pointer to receive remaining device path * Return: matching handle */ -static efi_handle_t find_handle(struct efi_device_path *dp, bool short_path, - struct efi_device_path **rem) +static efi_handle_t find_handle(struct efi_device_path *dp, + const efi_guid_t *guid, bool short_path, + struct efi_device_path **rem) { efi_handle_t handle, best_handle = NULL; efi_uintn_t len, best_len = 0; @@ -183,6 +185,11 @@ static efi_handle_t find_handle(struct efi_device_path *dp, bool short_path, efi_uintn_t len_current; efi_status_t ret; + if (guid) { + ret = efi_search_protocol(handle, guid, &handler); + if (ret != EFI_SUCCESS) + continue; + } ret = efi_search_protocol(handle, &efi_guid_device_path, &handler); if (ret != EFI_SUCCESS) @@ -195,13 +202,13 @@ static efi_handle_t find_handle(struct efi_device_path *dp, bool short_path, } len_current = efi_dp_instance_size(dp_current); if (rem) { - if (len_current < len) + if (len_current > len) continue; } else { if (len_current != len) continue; } - if (memcmp(dp_current, dp, len)) + if (memcmp(dp_current, dp, len_current)) continue; if (!rem) return handle; @@ -220,18 +227,20 @@ static efi_handle_t find_handle(struct efi_device_path *dp, bool short_path, * If @rem is provided, the handle with the longest partial match is returned. * * @dp: device path to search + * @guid: GUID of protocol that must be installed on path or NULL * @rem: pointer to receive remaining device path * Return: matching handle */ efi_handle_t efi_dp_find_obj(struct efi_device_path *dp, + const efi_guid_t *guid, struct efi_device_path **rem) { efi_handle_t handle; - handle = find_handle(dp, false, rem); + handle = find_handle(dp, guid, false, rem); if (!handle) /* Match short form device path */ - handle = find_handle(dp, true, rem); + handle = find_handle(dp, guid, true, rem); return handle; } -- cgit v1.2.3 From df96deeed6a9b34e76544ebe9b0fdd2e44ceb6cd Mon Sep 17 00:00:00 2001 From: Heinrich Schuchardt Date: Mon, 21 Mar 2022 08:26:48 +0100 Subject: efi_loader: typo devie-path %s/devie-path/device-path/ Reported-by: Ilias Apalodimas Signed-off-by: Heinrich Schuchardt --- lib/efi_loader/efi_device_path.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/efi_loader/efi_device_path.c') diff --git a/lib/efi_loader/efi_device_path.c b/lib/efi_loader/efi_device_path.c index 0a8802903d7..0542aaae16c 100644 --- a/lib/efi_loader/efi_device_path.c +++ b/lib/efi_loader/efi_device_path.c @@ -137,7 +137,7 @@ int efi_dp_match(const struct efi_device_path *a, * * See UEFI spec (section 3.1.2, about short-form device-paths) * - * @dp: original devie-path + * @dp: original device-path * @Return: shortened device-path or NULL */ struct efi_device_path *efi_dp_shorten(struct efi_device_path *dp) -- cgit v1.2.3