From 3b1d1e4e31ba17eba2271f34a6c1db4ba1a883c0 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sat, 26 Aug 2023 11:40:32 +0300
Subject: [PATCH] hidapi: sync the hidraw changes with mainstream
Apply mainstream commit 8a4de63b (mainstream PR/601) to our hidapi.
The patch is a direct apply of the mentioned commit, with one sdl-
specific part guarded by HIDAPI_IGNORE_DEVICE adapted accordingly.
---
src/hidapi/libusb/hid.c | 12 +++-
src/hidapi/linux/hid.c | 130 +++++++++++++++++++++++++++++-----------
2 files changed, 104 insertions(+), 38 deletions(-)
diff --git a/src/hidapi/libusb/hid.c b/src/hidapi/libusb/hid.c
index d6b73801c7ca..9bec8e2e8340 100644
--- a/src/hidapi/libusb/hid.c
+++ b/src/hidapi/libusb/hid.c
@@ -259,8 +259,16 @@ static int get_usage(uint8_t *report_descriptor, size_t size,
//printf("Usage Page: %x\n", (uint32_t)*usage_page);
}
if (key_cmd == 0x8) {
- *usage = get_bytes(report_descriptor, size, data_len, i);
- usage_found = 1;
+ if (data_len == 4) { /* Usages 5.5 / Usage Page 6.2.2.7 */
+ *usage_page = get_bytes(report_descriptor, size, 2, i + 2);
+ usage_page_found = 1;
+ *usage = get_bytes(report_descriptor, size, 2, i);
+ usage_found = 1;
+ }
+ else {
+ *usage = get_bytes(report_descriptor, size, data_len, i);
+ usage_found = 1;
+ }
//printf("Usage: %x\n", (uint32_t)*usage);
}
diff --git a/src/hidapi/linux/hid.c b/src/hidapi/linux/hid.c
index 50f85f3b3fd7..507a2b1f7616 100644
--- a/src/hidapi/linux/hid.c
+++ b/src/hidapi/linux/hid.c
@@ -206,7 +206,7 @@ static wchar_t *copy_udev_string(struct udev_device *dev, const char *udev_name)
* Returns 1 if successful, 0 if an invalid key
* Sets data_len and key_size when successful
*/
-static int get_hid_item_size(__u8 *report_descriptor, unsigned int pos, __u32 size, int *data_len, int *key_size)
+static int get_hid_item_size(const __u8 *report_descriptor, __u32 size, unsigned int pos, int *data_len, int *key_size)
{
int key = report_descriptor[pos];
int size_code;
@@ -262,7 +262,7 @@ static int get_hid_item_size(__u8 *report_descriptor, unsigned int pos, __u32 si
* Get bytes from a HID Report Descriptor.
* Only call with a num_bytes of 0, 1, 2, or 4.
*/
-static __u32 get_hid_report_bytes(__u8 *rpt, size_t len, size_t num_bytes, size_t cur)
+static __u32 get_hid_report_bytes(const __u8 *rpt, size_t len, size_t num_bytes, size_t cur)
{
/* Return if there aren't enough bytes. */
if (cur + num_bytes >= len)
@@ -285,6 +285,60 @@ static __u32 get_hid_report_bytes(__u8 *rpt, size_t len, size_t num_bytes, size_
return 0;
}
+/*
+ * Iterates until the end of a Collection.
+ * Assumes that *pos is exactly at the beginning of a Collection.
+ * Skips all nested Collection, i.e. iterates until the end of current level Collection.
+ *
+ * The return value is non-0 when an end of current Collection is found,
+ * 0 when error is occured (broken Descriptor, end of a Collection is found before its begin,
+ * or no Collection is found at all).
+ */
+static int hid_iterate_over_collection(const __u8 *report_descriptor, __u32 size, unsigned int *pos, int *data_len, int *key_size)
+{
+ int collection_level = 0;
+
+ while (*pos < size) {
+ int key = report_descriptor[*pos];
+ int key_cmd = key & 0xfc;
+
+ /* Determine data_len and key_size */
+ if (!get_hid_item_size(report_descriptor, size, *pos, data_len, key_size))
+ return 0; /* malformed report */
+
+ switch (key_cmd) {
+ case 0xa0: /* Collection 6.2.2.4 (Main) */
+ collection_level++;
+ break;
+ case 0xc0: /* End Collection 6.2.2.4 (Main) */
+ collection_level--;
+ break;
+ }
+
+ if (collection_level < 0) {
+ /* Broken descriptor or someone is using this function wrong,
+ * i.e. should be called exactly at the collection start */
+ return 0;
+ }
+
+ if (collection_level == 0) {
+ /* Found it!
+ * Also possible when called not at the collection start, but should not happen if used correctly */
+ return 1;
+ }
+
+ *pos += *data_len + *key_size;
+ }
+
+ return 0; /* Did not find the end of a Collection */
+}
+
+struct hid_usage_iterator {
+ unsigned int pos;
+ int usage_page_found;
+ unsigned short usage_page;
+};
+
/*
* Retrieves the device's Usage Page and Usage from the report descriptor.
* The algorithm returns the current Usage Page/Usage pair whenever a new
@@ -302,63 +356,64 @@ static __u32 get_hid_report_bytes(__u8 *rpt, size_t len, size_t num_bytes, size_
* 1 when finished processing descriptor.
* -1 on a malformed report.
*/
-static int get_next_hid_usage(__u8 *report_descriptor, __u32 size, unsigned int *pos, unsigned short *usage_page, unsigned short *usage)
+static int get_next_hid_usage(const __u8 *report_descriptor, __u32 size, struct hid_usage_iterator *ctx, unsigned short *usage_page, unsigned short *usage)
{
int data_len, key_size;
- int initial = *pos == 0; /* Used to handle case where no top-level application collection is defined */
- int usage_pair_ready = 0;
+ int initial = ctx->pos == 0; /* Used to handle case where no top-level application collection is defined */
- /* Usage is a Local Item, it must be set before each Main Item (Collection) before a pair is returned */
int usage_found = 0;
- while (*pos < size) {
- int key = report_descriptor[*pos];
+ while (ctx->pos < size) {
+ int key = report_descriptor[ctx->pos];
int key_cmd = key & 0xfc;
/* Determine data_len and key_size */
- if (!get_hid_item_size(report_descriptor, *pos, size, &data_len, &key_size))
+ if (!get_hid_item_size(report_descriptor, size, ctx->pos, &data_len, &key_size))
return -1; /* malformed report */
switch (key_cmd) {
case 0x4: /* Usage Page 6.2.2.7 (Global) */
- *usage_page = get_hid_report_bytes(report_descriptor, size, data_len, *pos);
+ ctx->usage_page = get_hid_report_bytes(report_descriptor, size, data_len, ctx->pos);
+ ctx->usage_page_found = 1;
break;
case 0x8: /* Usage 6.2.2.8 (Local) */
- *usage = get_hid_report_bytes(report_descriptor, size, data_len, *pos);
- usage_found = 1;
+ if (data_len == 4) { /* Usages 5.5 / Usage Page 6.2.2.7 */
+ ctx->usage_page = get_hid_report_bytes(report_descriptor, size, 2, ctx->pos + 2);
+ ctx->usage_page_found = 1;
+ *usage = get_hid_report_bytes(report_descriptor, size, 2, ctx->pos);
+ usage_found = 1;
+ }
+ else {
+ *usage = get_hid_report_bytes(report_descriptor, size, data_len, ctx->pos);
+ usage_found = 1;
+ }
break;
case 0xa0: /* Collection 6.2.2.4 (Main) */
- /* A Usage Item (Local) must be found for the pair to be valid */
- if (usage_found)
- usage_pair_ready = 1;
+ if (!hid_iterate_over_collection(report_descriptor, size, &ctx->pos, &data_len, &key_size)) {
+ return -1;
+ }
- /* Usage is a Local Item, unset it */
- usage_found = 0;
- break;
+ /* A pair is valid - to be reported when Collection is found */
+ if (usage_found && ctx->usage_page_found) {
+ *usage_page = ctx->usage_page;
+ return 0;
+ }
- case 0x80: /* Input 6.2.2.4 (Main) */
- case 0x90: /* Output 6.2.2.4 (Main) */
- case 0xb0: /* Feature 6.2.2.4 (Main) */
- case 0xc0: /* End Collection 6.2.2.4 (Main) */
- /* Usage is a Local Item, unset it */
- usage_found = 0;
break;
}
/* Skip over this key and its associated data */
- *pos += data_len + key_size;
-
- /* Return usage pair */
- if (usage_pair_ready)
- return 0;
+ ctx->pos += data_len + key_size;
}
/* If no top-level application collection is found and usage page/usage pair is found, pair is valid
https://docs.microsoft.com/en-us/windows-hardware/drivers/hid/top-level-collections */
- if (initial && usage_found)
- return 0; /* success */
+ if (initial && usage_found && ctx->usage_page_found) {
+ *usage_page = ctx->usage_page;
+ return 0; /* success */
+ }
return 1; /* finished processing */
}
@@ -804,12 +859,14 @@ static struct hid_device_info * create_device_info_for_device(struct udev_device
result = get_hid_report_descriptor_from_sysfs(sysfs_path, &report_desc);
if (result >= 0) {
unsigned short page = 0, usage = 0;
- unsigned int pos = 0;
+ struct hid_usage_iterator usage_iterator;
+ memset(&usage_iterator, 0, sizeof(usage_iterator));
+
/*
* Parse the first usage and usage page
* out of the report descriptor.
*/
- if (!get_next_hid_usage(report_desc.value, report_desc.size, &pos, &page, &usage)) {
+ if (!get_next_hid_usage(report_desc.value, report_desc.size, &usage_iterator, &page, &usage)) {
cur_dev->usage_page = page;
cur_dev->usage = usage;
}
@@ -818,7 +875,7 @@ static struct hid_device_info * create_device_info_for_device(struct udev_device
* Parse any additional usage and usage pages
* out of the report descriptor.
*/
- while (!get_next_hid_usage(report_desc.value, report_desc.size, &pos, &page, &usage)) {
+ while (!get_next_hid_usage(report_desc.value, report_desc.size, &usage_iterator, &page, &usage)) {
/* Create new record for additional usage pairs */
struct hid_device_info *tmp = (struct hid_device_info*) calloc(1, sizeof(struct hid_device_info));
struct hid_device_info *prev_dev = cur_dev;
@@ -980,9 +1037,10 @@ struct hid_device_info HID_API_EXPORT *hid_enumerate(unsigned short vendor_id,
struct hidraw_report_descriptor report_desc;
unsigned short page = 0, usage = 0;
- unsigned int pos = 0;
if (get_hid_report_descriptor_from_sysfs(sysfs_path, &report_desc) >= 0) {
- get_next_hid_usage(report_desc.value, report_desc.size, &pos, &page, &usage);
+ struct hid_usage_iterator usage_iterator;
+ memset(&usage_iterator, 0, sizeof(usage_iterator));
+ get_next_hid_usage(report_desc.value, report_desc.size, &usage_iterator, &page, &usage);
}
if (HIDAPI_IGNORE_DEVICE(bus_type, dev_vid, dev_pid, page, usage)) {
continue;