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![Quentin Lambert](/assets/img/avatar_default.png)
Checkpatch printed a style ERROR concerning a missing space before '('. This patch fixes this issue. Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
535 lines
14 KiB
C
535 lines
14 KiB
C
/*
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* Greybus manifest parsing
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*
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* Copyright 2014-2015 Google Inc.
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* Copyright 2014-2015 Linaro Ltd.
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*
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* Released under the GPLv2 only.
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*/
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#include "greybus.h"
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static const char *get_descriptor_type_string(u8 type)
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{
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switch (type) {
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case GREYBUS_TYPE_INVALID:
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return "invalid";
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case GREYBUS_TYPE_STRING:
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return "string";
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case GREYBUS_TYPE_INTERFACE:
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return "interface";
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case GREYBUS_TYPE_CPORT:
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return "cport";
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case GREYBUS_TYPE_BUNDLE:
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return "bundle";
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default:
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WARN_ON(1);
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return "unknown";
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}
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}
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/*
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* We scan the manifest once to identify where all the descriptors
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* are. The result is a list of these manifest_desc structures. We
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* then pick through them for what we're looking for (starting with
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* the interface descriptor). As each is processed we remove it from
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* the list. When we're done the list should (probably) be empty.
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*/
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struct manifest_desc {
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struct list_head links;
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size_t size;
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void *data;
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enum greybus_descriptor_type type;
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};
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static void release_manifest_descriptor(struct manifest_desc *descriptor)
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{
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list_del(&descriptor->links);
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kfree(descriptor);
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}
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static void release_manifest_descriptors(struct gb_interface *intf)
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{
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struct manifest_desc *descriptor;
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struct manifest_desc *next;
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list_for_each_entry_safe(descriptor, next, &intf->manifest_descs, links)
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release_manifest_descriptor(descriptor);
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}
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static void release_cport_descriptors(struct list_head *head, u8 bundle_id)
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{
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struct manifest_desc *desc, *tmp;
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struct greybus_descriptor_cport *desc_cport;
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list_for_each_entry_safe(desc, tmp, head, links) {
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desc_cport = desc->data;
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if (desc->type != GREYBUS_TYPE_CPORT)
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continue;
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if (desc_cport->bundle == bundle_id)
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release_manifest_descriptor(desc);
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}
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}
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static struct manifest_desc *get_next_bundle_desc(struct gb_interface *intf)
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{
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struct manifest_desc *descriptor;
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struct manifest_desc *next;
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list_for_each_entry_safe(descriptor, next, &intf->manifest_descs, links)
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if (descriptor->type == GREYBUS_TYPE_BUNDLE)
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return descriptor;
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return NULL;
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}
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/*
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* Validate the given descriptor. Its reported size must fit within
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* the number of bytes remaining, and it must have a recognized
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* type. Check that the reported size is at least as big as what
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* we expect to see. (It could be bigger, perhaps for a new version
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* of the format.)
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*
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* Returns the (non-zero) number of bytes consumed by the descriptor,
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* or a negative errno.
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*/
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static int identify_descriptor(struct gb_interface *intf,
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struct greybus_descriptor *desc, size_t size)
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{
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struct greybus_descriptor_header *desc_header = &desc->header;
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struct manifest_desc *descriptor;
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size_t desc_size;
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size_t expected_size;
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if (size < sizeof(*desc_header)) {
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dev_err(&intf->dev, "manifest too small (%zu < %zu)\n",
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size, sizeof(*desc_header));
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return -EINVAL; /* Must at least have header */
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}
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desc_size = le16_to_cpu(desc_header->size);
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if (desc_size > size) {
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dev_err(&intf->dev, "descriptor too big (%zu > %zu)\n",
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desc_size, size);
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return -EINVAL;
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}
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/* Descriptor needs to at least have a header */
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expected_size = sizeof(*desc_header);
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switch (desc_header->type) {
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case GREYBUS_TYPE_STRING:
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expected_size += sizeof(struct greybus_descriptor_string);
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expected_size += desc->string.length;
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/* String descriptors are padded to 4 byte boundaries */
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expected_size = ALIGN(expected_size, 4);
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break;
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case GREYBUS_TYPE_INTERFACE:
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expected_size += sizeof(struct greybus_descriptor_interface);
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break;
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case GREYBUS_TYPE_BUNDLE:
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expected_size += sizeof(struct greybus_descriptor_bundle);
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break;
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case GREYBUS_TYPE_CPORT:
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expected_size += sizeof(struct greybus_descriptor_cport);
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break;
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case GREYBUS_TYPE_INVALID:
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default:
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dev_err(&intf->dev, "invalid descriptor type (%u)\n",
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desc_header->type);
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return -EINVAL;
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}
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if (desc_size < expected_size) {
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dev_err(&intf->dev, "%s descriptor too small (%zu < %zu)\n",
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get_descriptor_type_string(desc_header->type),
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desc_size, expected_size);
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return -EINVAL;
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}
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/* Descriptor bigger than what we expect */
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if (desc_size > expected_size) {
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dev_warn(&intf->dev, "%s descriptor size mismatch (want %zu got %zu)\n",
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get_descriptor_type_string(desc_header->type),
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expected_size, desc_size);
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}
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descriptor = kzalloc(sizeof(*descriptor), GFP_KERNEL);
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if (!descriptor)
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return -ENOMEM;
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descriptor->size = desc_size;
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descriptor->data = (char *)desc + sizeof(*desc_header);
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descriptor->type = desc_header->type;
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list_add_tail(&descriptor->links, &intf->manifest_descs);
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/* desc_size is positive and is known to fit in a signed int */
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return desc_size;
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}
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/*
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* Find the string descriptor having the given id, validate it, and
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* allocate a duplicate copy of it. The duplicate has an extra byte
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* which guarantees the returned string is NUL-terminated.
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*
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* String index 0 is valid (it represents "no string"), and for
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* that a null pointer is returned.
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*
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* Otherwise returns a pointer to a newly-allocated copy of the
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* descriptor string, or an error-coded pointer on failure.
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*/
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static char *gb_string_get(struct gb_interface *intf, u8 string_id)
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{
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struct greybus_descriptor_string *desc_string;
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struct manifest_desc *descriptor;
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bool found = false;
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char *string;
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/* A zero string id means no string (but no error) */
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if (!string_id)
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return NULL;
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list_for_each_entry(descriptor, &intf->manifest_descs, links) {
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if (descriptor->type != GREYBUS_TYPE_STRING)
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continue;
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desc_string = descriptor->data;
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if (desc_string->id == string_id) {
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found = true;
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break;
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}
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}
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if (!found)
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return ERR_PTR(-ENOENT);
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/* Allocate an extra byte so we can guarantee it's NUL-terminated */
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string = kmemdup(&desc_string->string, desc_string->length + 1,
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GFP_KERNEL);
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if (!string)
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return ERR_PTR(-ENOMEM);
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string[desc_string->length] = '\0';
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/* Ok we've used this string, so we're done with it */
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release_manifest_descriptor(descriptor);
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return string;
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}
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/*
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* Find cport descriptors in the manifest associated with the given
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* bundle, and set up data structures for the functions that use
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* them. Returns the number of cports set up for the bundle, or 0
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* if there is an error.
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*/
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static u32 gb_manifest_parse_cports(struct gb_bundle *bundle)
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{
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struct gb_interface *intf = bundle->intf;
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struct greybus_descriptor_cport *desc_cport;
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struct manifest_desc *desc, *next, *tmp;
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LIST_HEAD(list);
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u8 bundle_id = bundle->id;
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u16 cport_id;
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u32 count = 0;
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int i;
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/* Set up all cport descriptors associated with this bundle */
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list_for_each_entry_safe(desc, next, &intf->manifest_descs, links) {
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if (desc->type != GREYBUS_TYPE_CPORT)
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continue;
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desc_cport = desc->data;
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if (desc_cport->bundle != bundle_id)
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continue;
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cport_id = le16_to_cpu(desc_cport->id);
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if (cport_id > CPORT_ID_MAX)
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goto exit;
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/* Nothing else should have its cport_id as control cport id */
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if (cport_id == GB_CONTROL_CPORT_ID) {
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dev_err(&bundle->dev, "invalid cport id found (%02u)\n",
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cport_id);
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goto exit;
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}
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/*
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* Found one, move it to our temporary list after checking for
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* duplicates.
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*/
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list_for_each_entry(tmp, &list, links) {
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desc_cport = tmp->data;
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if (cport_id == le16_to_cpu(desc_cport->id)) {
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dev_err(&bundle->dev,
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"duplicate CPort %u found\n",
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cport_id);
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goto exit;
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}
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}
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list_move_tail(&desc->links, &list);
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count++;
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}
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if (!count)
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return 0;
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bundle->cport_desc = kcalloc(count, sizeof(*bundle->cport_desc),
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GFP_KERNEL);
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if (!bundle->cport_desc)
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goto exit;
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bundle->num_cports = count;
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i = 0;
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list_for_each_entry_safe(desc, next, &list, links) {
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desc_cport = desc->data;
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memcpy(&bundle->cport_desc[i++], desc_cport,
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sizeof(*desc_cport));
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/* Release the cport descriptor */
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release_manifest_descriptor(desc);
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}
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return count;
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exit:
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release_cport_descriptors(&list, bundle_id);
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/*
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* Free all cports for this bundle to avoid 'excess descriptors'
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* warnings.
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*/
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release_cport_descriptors(&intf->manifest_descs, bundle_id);
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return 0; /* Error; count should also be 0 */
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}
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/*
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* Find bundle descriptors in the manifest and set up their data
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* structures. Returns the number of bundles set up for the
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* given interface.
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*/
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static u32 gb_manifest_parse_bundles(struct gb_interface *intf)
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{
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struct manifest_desc *desc;
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struct gb_bundle *bundle;
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struct gb_bundle *bundle_next;
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u32 count = 0;
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u8 bundle_id;
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u8 class;
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while ((desc = get_next_bundle_desc(intf))) {
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struct greybus_descriptor_bundle *desc_bundle;
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/* Found one. Set up its bundle structure*/
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desc_bundle = desc->data;
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bundle_id = desc_bundle->id;
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class = desc_bundle->class;
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/* Done with this bundle descriptor */
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release_manifest_descriptor(desc);
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/* Ignore any legacy control bundles */
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if (bundle_id == GB_CONTROL_BUNDLE_ID) {
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dev_dbg(&intf->dev, "%s - ignoring control bundle\n",
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__func__);
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release_cport_descriptors(&intf->manifest_descs,
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bundle_id);
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continue;
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}
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/* Nothing else should have its class set to control class */
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if (class == GREYBUS_CLASS_CONTROL) {
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dev_err(&intf->dev,
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"bundle %u cannot use control class\n",
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bundle_id);
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goto cleanup;
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}
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bundle = gb_bundle_create(intf, bundle_id, class);
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if (!bundle)
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goto cleanup;
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/*
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* Now go set up this bundle's functions and cports.
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*
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* A 'bundle' represents a device in greybus. It may require
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* multiple cports for its functioning. If we fail to setup any
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* cport of a bundle, we better reject the complete bundle as
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* the device may not be able to function properly then.
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*
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* But, failing to setup a cport of bundle X doesn't mean that
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* the device corresponding to bundle Y will not work properly.
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* Bundles should be treated as separate independent devices.
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*
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* While parsing manifest for an interface, treat bundles as
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* separate entities and don't reject entire interface and its
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* bundles on failing to initialize a cport. But make sure the
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* bundle which needs the cport, gets destroyed properly.
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*/
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if (!gb_manifest_parse_cports(bundle)) {
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gb_bundle_destroy(bundle);
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continue;
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}
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count++;
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}
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return count;
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cleanup:
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/* An error occurred; undo any changes we've made */
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list_for_each_entry_safe(bundle, bundle_next, &intf->bundles, links) {
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gb_bundle_destroy(bundle);
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count--;
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}
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return 0; /* Error; count should also be 0 */
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}
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static bool gb_manifest_parse_interface(struct gb_interface *intf,
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struct manifest_desc *interface_desc)
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{
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struct greybus_descriptor_interface *desc_intf = interface_desc->data;
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struct gb_control *control = intf->control;
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char *str;
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/* Handle the strings first--they can fail */
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str = gb_string_get(intf, desc_intf->vendor_stringid);
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if (IS_ERR(str))
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return false;
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control->vendor_string = str;
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str = gb_string_get(intf, desc_intf->product_stringid);
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if (IS_ERR(str))
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goto out_free_vendor_string;
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control->product_string = str;
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/* Assign feature flags communicated via manifest */
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intf->features = desc_intf->features;
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/* Release the interface descriptor, now that we're done with it */
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release_manifest_descriptor(interface_desc);
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/* An interface must have at least one bundle descriptor */
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if (!gb_manifest_parse_bundles(intf)) {
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dev_err(&intf->dev, "manifest bundle descriptors not valid\n");
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goto out_err;
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}
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return true;
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out_err:
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kfree(control->product_string);
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control->product_string = NULL;
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out_free_vendor_string:
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kfree(control->vendor_string);
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control->vendor_string = NULL;
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return false;
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}
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/*
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* Parse a buffer containing an interface manifest.
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*
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* If we find anything wrong with the content/format of the buffer
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* we reject it.
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*
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* The first requirement is that the manifest's version is
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* one we can parse.
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*
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* We make an initial pass through the buffer and identify all of
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* the descriptors it contains, keeping track for each its type
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* and the location size of its data in the buffer.
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*
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* Next we scan the descriptors, looking for an interface descriptor;
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* there must be exactly one of those. When found, we record the
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* information it contains, and then remove that descriptor (and any
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* string descriptors it refers to) from further consideration.
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*
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* After that we look for the interface's bundles--there must be at
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* least one of those.
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*
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* Returns true if parsing was successful, false otherwise.
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*/
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bool gb_manifest_parse(struct gb_interface *intf, void *data, size_t size)
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{
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struct greybus_manifest *manifest;
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struct greybus_manifest_header *header;
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struct greybus_descriptor *desc;
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struct manifest_desc *descriptor;
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struct manifest_desc *interface_desc = NULL;
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u16 manifest_size;
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u32 found = 0;
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bool result;
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/* Manifest descriptor list should be empty here */
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if (WARN_ON(!list_empty(&intf->manifest_descs)))
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return false;
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/* we have to have at _least_ the manifest header */
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if (size < sizeof(*header)) {
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dev_err(&intf->dev, "short manifest (%zu < %zu)\n",
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size, sizeof(*header));
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return false;
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}
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/* Make sure the size is right */
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manifest = data;
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header = &manifest->header;
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manifest_size = le16_to_cpu(header->size);
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if (manifest_size != size) {
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dev_err(&intf->dev, "manifest size mismatch (%zu != %u)\n",
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size, manifest_size);
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return false;
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}
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/* Validate major/minor number */
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if (header->version_major > GREYBUS_VERSION_MAJOR) {
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dev_err(&intf->dev, "manifest version too new (%u.%u > %u.%u)\n",
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header->version_major, header->version_minor,
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GREYBUS_VERSION_MAJOR, GREYBUS_VERSION_MINOR);
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return false;
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}
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/* OK, find all the descriptors */
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desc = manifest->descriptors;
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size -= sizeof(*header);
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while (size) {
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int desc_size;
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desc_size = identify_descriptor(intf, desc, size);
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if (desc_size < 0) {
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result = false;
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goto out;
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}
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desc = (struct greybus_descriptor *)((char *)desc + desc_size);
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size -= desc_size;
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}
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/* There must be a single interface descriptor */
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list_for_each_entry(descriptor, &intf->manifest_descs, links) {
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if (descriptor->type == GREYBUS_TYPE_INTERFACE)
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if (!found++)
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interface_desc = descriptor;
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}
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if (found != 1) {
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dev_err(&intf->dev, "manifest must have 1 interface descriptor (%u found)\n",
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found);
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result = false;
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goto out;
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}
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/* Parse the manifest, starting with the interface descriptor */
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result = gb_manifest_parse_interface(intf, interface_desc);
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/*
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* We really should have no remaining descriptors, but we
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* don't know what newer format manifests might leave.
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*/
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if (result && !list_empty(&intf->manifest_descs))
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dev_info(&intf->dev, "excess descriptors in interface manifest\n");
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out:
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release_manifest_descriptors(intf);
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return result;
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}
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