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link: don't allocate shared meta in shared mem

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We can't allocate the shared meta in shared mem because then clients can
damage it for other clients. Place it instead right after the buffer
metadata array. Filter out the shared metadata for a client, we send it
as part of the client_buffer structure.
Remove pointer metadata, it's not so useful.
Document the layout of the allocated buffers and the shared memory.
Work on metadata to define control parameters
This commit is contained in:
Wim Taymans 2017-11-17 13:34:42 +01:00
parent e774339ffe
commit 4d0bab799c
5 changed files with 158 additions and 69 deletions
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8
src/modules/module-client-node/client-node.c
View file

@ -540,7 +540,7 @@ spa_proxy_node_port_use_buffers(struct spa_node *node,
struct proxy *this;
struct impl *impl;
struct proxy_port *port;
uint32_t i, j;
uint32_t i, j, k;
size_t n_mem;
struct pw_client_node_buffer *mb;
struct spa_meta_shared *msh;
@ -600,9 +600,11 @@ spa_proxy_node_port_use_buffers(struct spa_node *node,
t->data.MemFd,
msh->fd, msh->flags, msh->offset, msh->size);
for (j = 0; j < buffers[i]->n_metas; j++) {
memcpy(&b->buffer.metas[j], &buffers[i]->metas[j], sizeof(struct spa_meta));
for (j = 0, k = 0; j < buffers[i]->n_metas; j++) {
if (buffers[i]->metas[j].type != t->meta.Shared)
memcpy(&b->buffer.metas[k++], &buffers[i]->metas[j], sizeof(struct spa_meta));
}
b->buffer.n_metas = k;
for (j = 0; j < buffers[i]->n_datas; j++) {
struct spa_data *d = &buffers[i]->datas[j];

107
src/pipewire/link.c
View file

@ -246,6 +246,78 @@ static struct spa_pod *find_param(struct spa_pod **params, int n_params, uint32_
return NULL;
}
/* Allocate an array of buffers that can be shared.
*
* All information will be allocated in \a mem. A pointer to a
* newly allocated memory with an array of buffer pointers is
* returned.
*
* \return an array of freshly allocated buffer pointers. free()
* after usage.
*
* Array of allocated buffers:
*
* +==============================+
* +-| struct spa_buffer * | array of n_buffers of pointers
* | | ... <n_buffers> |
* | +==============================+
* +>| struct spa_buffer |
* | uint32_t id | id of buffer
* | uint32_t n_metas | number of metas
* +-| struct spa_meta *metas | pointer to array of metas
* | | uint32_t n_datas | number of datas
* +|-| struct spa_data *datas | pointer to array of datas
* || +------------------------------+
* |+>| struct spa_meta |
* | | uint32_t type | Shared meta type, first one always shared
* |+-| void *data | pointer to inlined shared metadata
* || | uint32_t size | sizeof(struct spa_meta_shared)
* || | struct spa_meta |
* || | uint32_t type | more metadata
* +||-| void *data | pointer to mmaped metadata in shared memory
* ||| | uint32_t size | size of metadata
* ||| | ... <n_metas> | more metas follow
* ||| +------------------------------+
* ||+>| struct spa_meta_shared | inlined shared metadata
* || | uint32_t flags |
* || | int fd | fd of the shared memory block
* || | uint32_t offset | offset of meta/chunk/data for this buffer
* || | uint32_t size | size of meta/chunk/data for this buffer
* || +------------------------------+
* |+->| struct spa_data |
* | | uint32_t type | memory type, either MemFd or INVALID
* | | uint32_t flags |
* | | int fd | fd of shared memory block
* | | uint32_t mapoffset | offset in shared memory of data
* | | uint32_t maxsize | size of data block
* | +-| void *data | pointer to mmaped data in shared memory
* |+|-| struct spa_chunk *chunk | pointer to mmaped chunk in shared memory
* ||| | ... <n_datas> | more datas follow
* ||| +==============================+
* ||| | ... <n_buffers> | more buffer/meta/data definitions follow
* ||| +==============================+
* |||
* |||
* ||| shared memory block:
* |||
* ||| +==============================+
* +-->| meta data memory | metadata memory
* || | ... <n_metas> |
* || +------------------------------+
* +->| struct spa_chunk | memory for n_datas chunks
* | | struct spa_ringbuffer area |
* | | int32_t stride |
* | | ... <n_datas> chunks |
* | +------------------------------+
* +>| data | memory for n_datas data
* | ... <n_datas> blocks |
* +==============================+
* | ... <n_buffers> | repeated for each buffer
* +==============================+
*
* The shared memory block should not contain any types or structure,
* just the actual metadata contents.
*/
static struct spa_buffer **alloc_buffers(struct pw_link *this,
uint32_t n_buffers,
uint32_t n_params,
@ -265,17 +337,19 @@ static struct spa_buffer **alloc_buffers(struct pw_link *this,
n_metas = data_size = meta_size = 0;
/* each buffer */
/* each buffer has 1 meta shared */
skel_size = sizeof(struct spa_buffer);
skel_size += sizeof(struct spa_meta);
skel_size += sizeof(struct spa_meta_shared);
metas = alloca(sizeof(struct spa_meta) * (n_params + 1));
/* add shared metadata */
/* add shared metadata this should not go into shared
* memory or else a client can damage it so we inline it after
* the array of spa_meta. */
metas[n_metas].type = this->core->type.meta.Shared;
metas[n_metas].size = sizeof(struct spa_meta_shared);
meta_size += metas[n_metas].size;
n_metas++;
skel_size += sizeof(struct spa_meta);
/* collect metadata */
for (i = 0; i < n_params; i++) {
@ -316,31 +390,35 @@ static struct spa_buffer **alloc_buffers(struct pw_link *this,
for (i = 0; i < n_buffers; i++) {
int j;
struct spa_buffer *b;
struct spa_meta_shared *msh;
void *p;
buffers[i] = b = SPA_MEMBER(bp, skel_size * i, struct spa_buffer);
p = SPA_MEMBER(mem->ptr, data_size * i, void);
msh = SPA_MEMBER(b, sizeof(struct spa_buffer), struct spa_meta_shared);
msh->flags = 0;
msh->fd = mem->fd;
msh->offset = data_size * i;
msh->size = data_size;
b->id = i;
b->n_metas = n_metas;
b->metas = SPA_MEMBER(b, sizeof(struct spa_buffer), struct spa_meta);
b->metas = SPA_MEMBER(msh, sizeof(struct spa_meta_shared), struct spa_meta);
for (j = 0; j < n_metas; j++) {
struct spa_meta *m = &b->metas[j];
m->type = metas[j].type;
m->data = p;
m->size = metas[j].size;
if (m->type == this->core->type.meta.Shared) {
struct spa_meta_shared *msh = p;
msh->flags = 0;
msh->fd = mem->fd;
msh->offset = data_size * i;
msh->size = data_size;
m->data = msh;
}
else {
m->data = p;
p += m->size;
}
p += m->size;
}
/* pointer to data structure */
b->n_datas = n_datas;
@ -364,6 +442,7 @@ static struct spa_buffer **alloc_buffers(struct pw_link *this,
d->chunk->stride = data_strides[j];
ddp += data_sizes[j];
} else {
/* needs to be allocated by a node */
d->type = SPA_ID_INVALID;
d->data = NULL;
}
@ -535,6 +614,8 @@ static int do_allocation(struct pw_link *this, uint32_t in_state, uint32_t out_s
minsize = 1024;
}
/* when one of the ports can allocate buffer memory, set the minsize to
* 0 to make sure we don't allocate memory in the shared memory */
if ((in_flags & SPA_PORT_INFO_FLAG_CAN_ALLOC_BUFFERS) ||
(out_flags & SPA_PORT_INFO_FLAG_CAN_ALLOC_BUFFERS))
minsize = 0;