From 377d1db57dae282cda94a2c24994707a32efdd00 Mon Sep 17 00:00:00 2001 From: Patrick Georgi Date: Wed, 16 Sep 2015 18:53:40 +0200 Subject: libpayload: bring in file attribute support from cbfstool This comes from cbfstool (GPL) into libpayload (BSD-l), but I could have just as well written it in libpayload first. Change-Id: I86baefe5c299125a4733fa20523efd5d06de7182 Signed-off-by: Patrick Georgi Reviewed-on: http://review.coreboot.org/11675 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin --- payloads/libpayload/include/cbfs_core.h | 26 ++++++++++++++++++++- payloads/libpayload/libcbfs/cbfs_core.c | 41 +++++++++++++++++++++++++++++++++ 2 files changed, 66 insertions(+), 1 deletion(-) (limited to 'payloads') diff --git a/payloads/libpayload/include/cbfs_core.h b/payloads/libpayload/include/cbfs_core.h index a95cef7a3d..a2ee74459b 100644 --- a/payloads/libpayload/include/cbfs_core.h +++ b/payloads/libpayload/include/cbfs_core.h @@ -132,10 +132,34 @@ struct cbfs_file { char magic[8]; uint32_t len; uint32_t type; - uint32_t checksum; + uint32_t attributes_offset; uint32_t offset; + char filename[]; } __attribute__((packed)); +/* Depending on how the header was initialized, it may be backed with 0x00 or + * 0xff. Support both. */ +#define CBFS_FILE_ATTR_TAG_UNUSED 0 +#define CBFS_FILE_ATTR_TAG_UNUSED2 0xffffffff + +/* The common fields of extended cbfs file attributes. + Attributes are expected to start with tag/len, then append their + specific fields. */ +struct cbfs_file_attribute { + uint32_t tag; + /* len covers the whole structure, incl. tag and len */ + uint32_t len; + uint8_t data[0]; +} __attribute__((packed)); + +/* Given a cbfs_file, return the first file attribute, or NULL. */ +struct cbfs_file_attribute *cbfs_file_first_attr(struct cbfs_file *file); + +/* Given a cbfs_file and a cbfs_file_attribute, return the attribute that + * follows it, or NULL. */ +struct cbfs_file_attribute *cbfs_file_next_attr(struct cbfs_file *file, + struct cbfs_file_attribute *attr); + /*** Component sub-headers ***/ /* Following are component sub-headers for the "standard" diff --git a/payloads/libpayload/libcbfs/cbfs_core.c b/payloads/libpayload/libcbfs/cbfs_core.c index 7926d9d650..6a19b269c1 100644 --- a/payloads/libpayload/libcbfs/cbfs_core.c +++ b/payloads/libpayload/libcbfs/cbfs_core.c @@ -213,6 +213,47 @@ void *cbfs_get_file_content(struct cbfs_media *media, const char *name, return (void *)CBFS_SUBHEADER(file); } +struct cbfs_file_attribute *cbfs_file_first_attr(struct cbfs_file *file) +{ + /* attributes_offset should be 0 when there is no attribute, but all + * values that point into the cbfs_file header are invalid, too. */ + if (ntohl(file->attributes_offset) <= sizeof(*file)) + return NULL; + + /* There needs to be enough space for the file header and one + * attribute header for this to make sense. */ + if (ntohl(file->offset) <= + sizeof(*file) + sizeof(struct cbfs_file_attribute)) + return NULL; + + return (struct cbfs_file_attribute *) + (((uint8_t *)file) + ntohl(file->attributes_offset)); +} + +struct cbfs_file_attribute *cbfs_file_next_attr(struct cbfs_file *file, + struct cbfs_file_attribute *attr) +{ + /* ex falso sequitur quodlibet */ + if (attr == NULL) + return NULL; + + /* Is there enough space for another attribute? */ + if ((uint8_t *)attr + ntohl(attr->len) + + sizeof(struct cbfs_file_attribute) >= + (uint8_t *)file + ntohl(file->offset)) + return NULL; + + struct cbfs_file_attribute *next = (struct cbfs_file_attribute *) + (((uint8_t *)attr) + ntohl(attr->len)); + /* If any, "unused" attributes must come last. */ + if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED) + return NULL; + if (ntohl(next->tag) == CBFS_FILE_ATTR_TAG_UNUSED2) + return NULL; + + return next; +} + int cbfs_decompress(int algo, void *src, void *dst, int len) { switch (algo) { -- cgit v1.2.3