From: Michal Nazarewicz <mina86@xxxxxxxxxx>
This reworks the way SuperSpeed descriptors are added and instead of
having a magic after full and high speed descriptors, it reworks the
whole descriptors block to include a flags field which lists which
descriptors are present and makes future extensions possible.
Signed-off-by: Michal Nazarewicz <mina86@xxxxxxxxxx>
---
drivers/usb/gadget/f_fs.c | 132 +++++++++++++++---------------------
drivers/usb/gadget/u_fs.h | 12 ++--
include/uapi/linux/usb/functionfs.h | 49 +++++++------
3 files changed, 91 insertions(+), 102 deletions(-)
diff --git a/drivers/usb/gadget/f_fs.c b/drivers/usb/gadget/f_fs.c
index 5677c16..485a3fa 100644
--- a/drivers/usb/gadget/f_fs.c
+++ b/drivers/usb/gadget/f_fs.c
@@ -1169,7 +1169,7 @@ static void ffs_data_clear(struct ffs_data *ffs)
if (ffs->epfiles)
ffs_epfiles_destroy(ffs->epfiles, ffs->eps_count);
- kfree(ffs->raw_descs);
+ kfree(ffs->raw_descs_data);
kfree(ffs->raw_strings);
kfree(ffs->stringtabs);
}
@@ -1181,12 +1181,12 @@ static void ffs_data_reset(struct ffs_data *ffs)
ffs_data_clear(ffs);
ffs->epfiles = NULL;
+ ffs->raw_descs_data = NULL;
ffs->raw_descs = NULL;
ffs->raw_strings = NULL;
ffs->stringtabs = NULL;
- ffs->raw_fs_hs_descs_length = 0;
- ffs->raw_ss_descs_length = 0;
+ ffs->raw_descs_length = 0;
ffs->fs_descs_count = 0;
ffs->hs_descs_count = 0;
ffs->ss_descs_count = 0;
@@ -1600,89 +1600,76 @@ static int __ffs_data_do_entity(enum ffs_entity_type type,
static int __ffs_data_got_descs(struct ffs_data *ffs,
char *const _data, size_t len)
{
- unsigned fs_count, hs_count, ss_count = 0;
- int fs_len, hs_len, ss_len, ret = -EINVAL;
- char *data = _data;
+ char *data = _data, *raw_descs;
+ unsigned counts[3], flags;
+ int ret = -EINVAL, i;
ENTER();
- if (unlikely(get_unaligned_le32(data) != FUNCTIONFS_DESCRIPTORS_MAGIC ||
- get_unaligned_le32(data + 4) != len))
+ if (get_unaligned_le32(data + 4) != len)
goto error;
- fs_count = get_unaligned_le32(data + 8);
- hs_count = get_unaligned_le32(data + 12);
-
- data += 16;
- len -= 16;
- if (likely(fs_count)) {
- fs_len = ffs_do_descs(fs_count, data, len,
- __ffs_data_do_entity, ffs);
- if (unlikely(fs_len < 0)) {
- ret = fs_len;
+ switch (get_unaligned_le32(data)) {
+ case FUNCTIONFS_DESCRIPTORS_MAGIC:
+ flags = FUNCTIONFS_HAS_FS_DESC | FUNCTIONFS_HAS_HS_DESC;
+ data += 8;
+ len -= 8;
+ break;
+ case FUNCTIONFS_DESCRIPTORS_MAGIC_V2:
+ flags = get_unaligned_le32(data + 8);
+ if (flags & ~(FUNCTIONFS_HAS_FS_DESC |
+ FUNCTIONFS_HAS_HS_DESC |
+ FUNCTIONFS_HAS_SS_DESC)) {
+ ret = -ENOSYS;
goto error;
}
-
- data += fs_len;
- len -= fs_len;
- } else {
- fs_len = 0;
+ data += 12;
+ len -= 12;
+ break;
+ default:
+ goto error;
}
- if (likely(hs_count)) {
- hs_len = ffs_do_descs(hs_count, data, len,
- __ffs_data_do_entity, ffs);
- if (unlikely(hs_len < 0)) {
- ret = hs_len;
+ /* Read fs_count, hs_count and ss_count (if present) */
+ for (i = 0; i < 3; ++i) {
+ if (!(flags & (1 << i))) {
+ counts[i] = 0;
+ } else if (len < 4) {
goto error;
+ } else {
+ counts[i] = get_unaligned_le32(data);
+ data += 4;
+ len -= 4;
}
-
- data += hs_len;
- len -= hs_len;
- } else {
- hs_len = 0;
- }
-
- if (len >= 8) {
- /* Check SS_MAGIC for presence of ss_descs and get SS_COUNT */
- if (get_unaligned_le32(data) != FUNCTIONFS_SS_DESC_MAGIC)
- goto einval;
-
- ss_count = get_unaligned_le32(data + 4);
- data += 8;
- len -= 8;
}
- if (!fs_count && !hs_count && !ss_count)
- goto einval;
-
- if (ss_count) {
- ss_len = ffs_do_descs(ss_count, data, len,
+ /* Read descriptors */
+ raw_descs = data;
+ for (i = 0; i < 3; ++i) {
+ if (!counts[i])
+ continue;
+ ret = ffs_do_descs(counts[i], data, len,
__ffs_data_do_entity, ffs);
- if (unlikely(ss_len < 0)) {
- ret = ss_len;
+ if (ret < 0)
goto error;
- }
- ret = ss_len;
- } else {
- ss_len = 0;
- ret = 0;
+ data += ret;
+ len -= ret;
}
- if (unlikely(len != ret))
- goto einval;
+ if (raw_descs == data || len) {
+ ret = -EINVAL;
+ goto error;
+ }
- ffs->raw_fs_hs_descs_length = fs_len + hs_len;
- ffs->raw_ss_descs_length = ss_len;
- ffs->raw_descs = _data;
- ffs->fs_descs_count = fs_count;
- ffs->hs_descs_count = hs_count;
- ffs->ss_descs_count = ss_count;
+ ffs->raw_descs_data = _data;
+ ffs->raw_descs = raw_descs;
+ ffs->raw_descs_length = data - raw_descs;
+ ffs->fs_descs_count = counts[0];
+ ffs->hs_descs_count = counts[1];
+ ffs->ss_descs_count = counts[2];
return 0;
-einval:
- ret = -EINVAL;
error:
kfree(_data);
return ret;
@@ -2094,8 +2081,7 @@ static int _ffs_func_bind(struct usb_configuration *c,
vla_item_with_sz(d, struct usb_descriptor_header *, ss_descs,
super ? ffs->ss_descs_count + 1 : 0);
vla_item_with_sz(d, short, inums, ffs->interfaces_count);
- vla_item_with_sz(d, char, raw_descs,
- ffs->raw_fs_hs_descs_length + ffs->raw_ss_descs_length);
+ vla_item_with_sz(d, char, raw_descs, ffs->raw_descs_length);
char *vlabuf;
ENTER();
@@ -2111,15 +2097,9 @@ static int _ffs_func_bind(struct usb_configuration *c,
/* Zero */
memset(vla_ptr(vlabuf, d, eps), 0, d_eps__sz);
- /* Copy only raw (hs,fs) descriptors (until ss_magic and ss_count) */
- memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs + 16,
- ffs->raw_fs_hs_descs_length);
- /* Copy SS descs present @ header + hs_fs_descs + ss_magic + ss_count */
- if (func->ffs->ss_descs_count)
- memcpy(vla_ptr(vlabuf, d, raw_descs) +
- ffs->raw_fs_hs_descs_length,
- ffs->raw_descs + 16 + ffs->raw_fs_hs_descs_length + 8,
- ffs->raw_ss_descs_length);
+ /* Copy descriptors */
+ memcpy(vla_ptr(vlabuf, d, raw_descs), ffs->raw_descs,
+ ffs->raw_descs_length);
memset(vla_ptr(vlabuf, d, inums), 0xff, d_inums__sz);
for (ret = ffs->eps_count; ret; --ret) {
diff --git a/drivers/usb/gadget/u_fs.h b/drivers/usb/gadget/u_fs.h
index 08bf26e..46ddda9 100644
--- a/drivers/usb/gadget/u_fs.h
+++ b/drivers/usb/gadget/u_fs.h
@@ -210,15 +210,13 @@ struct ffs_data {
/* filled by __ffs_data_got_descs() */
/*
- * Real descriptors are 16 bytes after raw_descs (so you need
- * to skip 16 bytes (ie. ffs->raw_descs + 16) to get to the
- * first full speed descriptor).
- * raw_fs_hs_descs_length does not have those 16 bytes added.
- * ss_descs are 8 bytes (ss_magic + count) pass the hs_descs
+ * raw_descs is what you kfree, real_descs points inside of raw_descs,
+ * where full speed, high speed and super speed descriptors start.
+ * real_descs_length is the length of all those descriptors.
*/
+ const void *raw_descs_data;
const void *raw_descs;
- unsigned raw_fs_hs_descs_length;
- unsigned raw_ss_descs_length;
+ unsigned raw_descs_length;
unsigned fs_descs_count;
unsigned hs_descs_count;
unsigned ss_descs_count;
diff --git a/include/uapi/linux/usb/functionfs.h b/include/uapi/linux/usb/functionfs.h
index 0f8f7be..2a4b4a7 100644
--- a/include/uapi/linux/usb/functionfs.h
+++ b/include/uapi/linux/usb/functionfs.h
@@ -10,10 +10,15 @@
enum {
FUNCTIONFS_DESCRIPTORS_MAGIC = 1,
- FUNCTIONFS_STRINGS_MAGIC = 2
+ FUNCTIONFS_STRINGS_MAGIC = 2,
+ FUNCTIONFS_DESCRIPTORS_MAGIC_V2 = 3,
};
-#define FUNCTIONFS_SS_DESC_MAGIC 0x0055DE5C
+enum functionfs_flags {
+ FUNCTIONFS_HAS_FS_DESC = 1,
+ FUNCTIONFS_HAS_HS_DESC = 2,
+ FUNCTIONFS_HAS_SS_DESC = 4,
+};
#ifndef __KERNEL__
@@ -30,33 +35,39 @@ struct usb_endpoint_descriptor_no_audio {
/*
- * All numbers must be in little endian order.
- */
-
-struct usb_functionfs_descs_head {
- __le32 magic;
- __le32 length;
- __le32 fs_count;
- __le32 hs_count;
-} __attribute__((packed));
-
-/*
* Descriptors format:
*
* | off | name | type | description |
* |-----+-----------+--------------+--------------------------------------|
- * | 0 | magic | LE32 | FUNCTIONFS_{FS,HS}_DESCRIPTORS_MAGIC |
+ * | 0 | magic | LE32 | FUNCTIONFS_DESCRIPTORS_MAGIC_V2 |
+ * | 4 | length | LE32 | length of the whole data chunk |
+ * | 8 | flags | LE32 | combination of functionfs_flags |
+ * | | fs_count | LE32 | number of full-speed descriptors |
+ * | | hs_count | LE32 | number of high-speed descriptors |
+ * | | ss_count | LE32 | number of super-speed descriptors |
+ * | | fs_descrs | Descriptor[] | list of full-speed descriptors |
+ * | | hs_descrs | Descriptor[] | list of high-speed descriptors |
+ * | | ss_descrs | Descriptor[] | list of super-speed descriptors |
+ *
+ * Depending on which flags are set, various fields may be missing in the
+ * structure. Any flags that are not recognised cause the whole block to be
+ * rejected with -ENOSYS.
+ *
+ * Legacy descriptors format:
+ *
+ * | off | name | type | description |
+ * |-----+-----------+--------------+--------------------------------------|
+ * | 0 | magic | LE32 | FUNCTIONFS_DESCRIPTORS_MAGIC |
* | 4 | length | LE32 | length of the whole data chunk |
* | 8 | fs_count | LE32 | number of full-speed descriptors |
* | 12 | hs_count | LE32 | number of high-speed descriptors |
* | 16 | fs_descrs | Descriptor[] | list of full-speed descriptors |
* | | hs_descrs | Descriptor[] | list of high-speed descriptors |
- * | | ss_magic | LE32 | FUNCTIONFS_SS_DESC_MAGIC |
- * | | ss_count | LE32 | number of super-speed descriptors |
- * | | ss_descrs | Descriptor[] | list of super-speed descriptors |
*
- * ss_magic: if present then it implies that SS_DESCs are also present
- * descs are just valid USB descriptors and have the following format:
+ * All numbers must be in little endian order.
+ *
+ * Descriptor[] is an array of valid USB descriptors which have the following
+ * format:
*
* | off | name | type | description |
* |-----+-----------------+------+--------------------------|
--
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