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/***
This file is part of PulseAudio.
Copyright 2004-2006 Lennart Poettering
PulseAudio is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
PulseAudio is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with PulseAudio; if not, see <http://www.gnu.org/licenses/>.
***/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <pulsecore/core-util.h>
#include <pulsecore/macro.h>
#include <pulsecore/native-common.h>
#include <pulsecore/pstream.h>
#include <pulsecore/refcnt.h>
#include <pulse/xmalloc.h>
#include "pstream-util.h"
static void pa_pstream_send_tagstruct_with_ancil_data(pa_pstream *p, pa_tagstruct *t, pa_cmsg_ancil_data *ancil_data) {
size_t length;
const uint8_t *data;
pa_packet *packet;
pa_assert(p);
pa_assert(t);
pa_assert_se(data = pa_tagstruct_data(t, &length));
pa_assert_se(packet = pa_packet_new_data(data, length));
pa_tagstruct_free(t);
pa_pstream_send_packet(p, packet, ancil_data);
pa_packet_unref(packet);
}
#ifdef HAVE_CREDS
void pa_pstream_send_tagstruct_with_creds(pa_pstream *p, pa_tagstruct *t, const pa_creds *creds) {
if (creds) {
pa_cmsg_ancil_data a;
a.nfd = 0;
a.creds_valid = true;
a.creds = *creds;
pa_pstream_send_tagstruct_with_ancil_data(p, t, &a);
}
else
pa_pstream_send_tagstruct_with_ancil_data(p, t, NULL);
}
/* @close_fds: If set then the pstreams code, after invoking a sendmsg(),
* will close all passed fds.
*
* Such fds cannot be closed here as this might lead to freeing them
* before they're actually passed to the other end. The internally-used
* pa_pstream_send_packet() does not do any actual writes and just
* defers write events over the pstream. */
void pa_pstream_send_tagstruct_with_fds(pa_pstream *p, pa_tagstruct *t, int nfd, const int *fds,
bool close_fds) {
if (nfd > 0) {
pa_cmsg_ancil_data a;
a.nfd = nfd;
a.creds_valid = false;
a.close_fds_on_cleanup = close_fds;
pa_assert(nfd <= MAX_ANCIL_DATA_FDS);
memcpy(a.fds, fds, sizeof(int) * nfd);
pa_pstream_send_tagstruct_with_ancil_data(p, t, &a);
}
else
pa_pstream_send_tagstruct_with_ancil_data(p, t, NULL);
}
#else
void pa_pstream_send_tagstruct_with_creds(pa_pstream *p, pa_tagstruct *t, const pa_creds *creds) {
pa_pstream_send_tagstruct_with_ancil_data(p, t, NULL);
}
void PA_GCC_NORETURN pa_pstream_send_tagstruct_with_fds(pa_pstream *p, pa_tagstruct *t, int nfd, const int *fds,
bool close_fds) {
pa_assert_not_reached();
}
#endif
void pa_pstream_send_error(pa_pstream *p, uint32_t tag, uint32_t error) {
pa_tagstruct *t;
pa_assert_se(t = pa_tagstruct_new());
pa_tagstruct_putu32(t, PA_COMMAND_ERROR);
pa_tagstruct_putu32(t, tag);
pa_tagstruct_putu32(t, error);
pa_pstream_send_tagstruct(p, t);
}
void pa_pstream_send_simple_ack(pa_pstream *p, uint32_t tag) {
pa_tagstruct *t;
pa_assert_se(t = pa_tagstruct_new());
pa_tagstruct_putu32(t, PA_COMMAND_REPLY);
pa_tagstruct_putu32(t, tag);
pa_pstream_send_tagstruct(p, t);
}
/* Before sending blocks from a memfd-backed pool over the pipe, we
* must call this method first.
*
* This is needed to transfer memfd blocks without passing their fd
* every time, thus minimizing overhead and avoiding fd leaks.
*
* On registration a packet is sent with the memfd fd as ancil data;
* such packet has an ID that uniquely identifies the pool's memfd
* region. Upon arrival the other end creates a permanent mapping
* between that ID and the passed memfd memory area.
*
* By doing so, we won't need to reference the pool's memfd fd any
* further - just its ID. Both endpoints can then close their fds. */
int pa_pstream_register_memfd_mempool(pa_pstream *p, pa_mempool *pool, const char **fail_reason) {
#if defined(HAVE_CREDS) && defined(HAVE_MEMFD)
unsigned shm_id;
int memfd_fd, ret = -1;
pa_tagstruct *t;
bool per_client_mempool;
pa_assert(p);
pa_assert(fail_reason);
*fail_reason = NULL;
per_client_mempool = pa_mempool_is_per_client(pool);
pa_pstream_ref(p);
if (!pa_mempool_is_shared(pool)) {
*fail_reason = "mempool is not shared";
goto finish;
}
if (!pa_mempool_is_memfd_backed(pool)) {
*fail_reason = "mempool is not memfd-backed";
goto finish;
}
if (pa_mempool_get_shm_id(pool, &shm_id)) {
*fail_reason = "could not extract pool SHM ID";
goto finish;
}
if (!pa_pstream_get_memfd(p)) {
*fail_reason = "pipe does not support memfd transport";
goto finish;
}
memfd_fd = (per_client_mempool) ? pa_mempool_take_memfd_fd(pool) :
pa_mempool_get_memfd_fd(pool);
/* Note! For per-client mempools we've taken ownership of the memfd
* fd, and we're thus the sole code path responsible for closing it.
* In case of any failure, it MUST be closed. */
if (pa_pstream_attach_memfd_shmid(p, shm_id, memfd_fd)) {
*fail_reason = "could not attach memfd SHM ID to pipe";
if (per_client_mempool)
pa_assert_se(pa_close(memfd_fd) == 0);
goto finish;
}
t = pa_tagstruct_new();
pa_tagstruct_putu32(t, PA_COMMAND_REGISTER_MEMFD_SHMID);
pa_tagstruct_putu32(t, (uint32_t) -1); /* tag */
pa_tagstruct_putu32(t, shm_id);
pa_pstream_send_tagstruct_with_fds(p, t, 1, &memfd_fd, per_client_mempool);
ret = 0;
finish:
pa_pstream_unref(p);
return ret;
#else
pa_assert(fail_reason);
*fail_reason = "memfd support not compiled in";
return -1;
#endif
}
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