diff options
Diffstat (limited to 'alsa-hook')
| -rw-r--r-- | alsa-hook/CMakeLists.txt | 38 | ||||
| -rw-r--r-- | alsa-hook/PolicyAlsaHook.c | 640 | ||||
| -rw-r--r-- | alsa-hook/README.md | 211 |
3 files changed, 889 insertions, 0 deletions
diff --git a/alsa-hook/CMakeLists.txt b/alsa-hook/CMakeLists.txt new file mode 100644 index 0000000..5f3cc6d --- /dev/null +++ b/alsa-hook/CMakeLists.txt @@ -0,0 +1,38 @@ +########################################################################### +# Copyright 2015, 2016, 2017 IoT.bzh +# +# author: Fulup Ar Foll <fulup@iot.bzh> +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +########################################################################### + +# Activate ALSA dynamic build build mode get resolve "snd_dlsym_start" +add_compile_options(-DPIC) + +PROJECT_TARGET_ADD(policy_alsa_hook) + + # Define targets + ADD_LIBRARY(${TARGET_NAME} MODULE PolicyAlsaHook.c) + + # Alsa Plugin properties + SET_TARGET_PROPERTIES(${TARGET_NAME} PROPERTIES + PREFIX "" + OUTPUT_NAME ${TARGET_NAME} + ) + + # Library dependencies (include updates automatically) + TARGET_LINK_LIBRARIES(${TARGET_NAME} + ${link_libraries} + ) + install(TARGETS ${TARGET_NAME} LIBRARY DESTINATION lib) + diff --git a/alsa-hook/PolicyAlsaHook.c b/alsa-hook/PolicyAlsaHook.c new file mode 100644 index 0000000..5e63825 --- /dev/null +++ b/alsa-hook/PolicyAlsaHook.c @@ -0,0 +1,640 @@ +/* + * Copyright (C) 2016 "IoT.bzh" + * Author Fulup Ar Foll <fulup@iot.bzh> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + * + * AfbCallBack (snd_ctl_hal_t *handle, int numid, void **response); + * AlsaHookInit is mandatory and called with numid=0 + * + * Syntax in .asoundrc file + * CrlLabel { cb MyFunctionName name "My_Second_Control" } + * + * Testing: + * aplay -DAlsaHook /usr/share/sounds/alsa/test.wav + * + * References: + * https://www.spinics.net/lists/alsa-devel/msg54235.html + * https://github.com/shivdasgujare/utilities/blob/master/nexuss/alsa-scenario-hook/src/alsa-wrapper.c + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <alloca.h> + +#include <alsa/asoundlib.h> +#include <alsa/conf.h> +#include <alsa/pcm.h> + +#include <systemd/sd-event.h> +#include <json-c/json.h> + +#include "afb/afb-wsj1.h" +#include "afb/afb-ws-client.h" +#include "afb/afb-proto-ws.h" + +#include <pthread.h> +#include <semaphore.h> + +#define PLUGIN_ENTRY_POINT AlsaInstallHook + // Fulup Note: What ever you may find on Internet you should use + // SND_CONFIG_DLSYM_VERSION_HOOK and not SND_CONFIG_DLSYM_VERSION_HOOK + SND_DLSYM_BUILD_VERSION(PLUGIN_ENTRY_POINT, SND_PCM_DLSYM_VERSION) + +// this should be more than enough +#define MAX_API_CALL 10 +#define MAX_EVT_CALL 10 + +// timeout in ms +#define REQUEST_DEFAULT_TIMEOUT 500 +#ifndef MAINLOOP_WATCHDOG +#define MAINLOOP_WATCHDOG 100000 +#endif + +// closing message is added to query when PCM is closed +#define CLOSING_MSG ",\"source\":-1}" + +// Currently not implemented +#define UNUSED_ARG(x) UNUSED_ ## x __attribute__((__unused__)) + +typedef struct { + const char *apiverb; + json_object *queryJ; + sd_event_source *evtSource; + char *callIdTag; + void *afbClient; +} afbRequestT; + +typedef struct { + const char *search; + const char *value; + int signal; +} afbEventT; + +typedef struct { + char *name; + const char *api; + char *uid; + snd_pcm_t *pcm; + const char *uri; + struct afb_proto_ws *pws; + sd_event *sdLoop; + int verbose; + int synchronous; + sem_t semaphore; + long timeout; + int count; + int error; + afbRequestT **request; + afbRequestT **release; + afbEventT **event; +} afbClientT; + + +static void *LoopInThread(void *handle) { + afbClientT *afbClient = (afbClientT*) handle; + int count=0; + int watchdog= MAINLOOP_WATCHDOG *1000; + + /* loop until end */ + for (;;) { + + if (afbClient->verbose) printf("ON-MAINLOOP ping=%d\n", count++); + sd_event_run(afbClient->sdLoop, watchdog); + } + + return NULL; +} + +// lost connect with the AudioDaemon +static void OnHangupCB(void *handle) { + + afbClientT *afbClient = (afbClientT*) handle; + SNDERR("(Hoops) Lost Connection to %s", afbClient->uri); + + // try to close PCM when impossible terminate client + int err = snd_pcm_close (afbClient->pcm); + if (err) exit(1); +} + +typedef enum { + HOOK_INSTALL, + HOOK_CLOSE, +} hookActionT; + +void OnEventCB(void *handle, const char *event, int evtid, struct json_object *dataJ) { + afbClientT *afbClient = (afbClientT*) handle; + afbEventT **afbEvent = afbClient->event; + json_object *tmpJ; + int done; + + // if no event handler just ignore events + if (!afbEvent) goto OnErrorExit; + + if (afbClient->verbose) printf("ON-EVENT processing signal event=%s search=%s\n", event, json_object_get_string(dataJ)); + + // loop on event/signal mapping table + for (int index=0; afbEvent[index]!= NULL; index++) { + done = json_object_object_get_ex(dataJ,afbEvent[index]->search, &tmpJ); + if (done) { + const char *value=json_object_get_string(tmpJ); + if (!strcmp(afbEvent[index]->value, value)) { + if (afbEvent[index]->signal) + if (afbClient->verbose) printf("ON-EVENT search=%s value=%s signal=%d\n", afbEvent[index]->search, value, afbEvent[index]->signal); + if (afbEvent[index]->signal) kill (getpid(), afbEvent[index]->signal); + } + } + } + + return; + +OnErrorExit: + if (afbClient->verbose) SNDERR("ON-EVENT Fail/Ignored %s(%s)\n", event, json_object_get_string(dataJ)); + return; +} + +static void OnSuccessCB(void* UNUSED_ARG(ctx) , void* handle, json_object* responseJ, const char* info) { + + afbRequestT *afbRequest= (afbRequestT*)handle; + afbClientT *afbClient=(afbClientT*)afbRequest->afbClient; + + if (afbClient->verbose) printf("OnSuccessCB callid='%s' response='%s' info='%s'\n", afbRequest->callIdTag, json_object_get_string(responseJ), info); + + // Cancel timeout for this request + sd_event_source_unref(afbRequest->evtSource); + free(afbRequest->callIdTag); + + // When not more waiting call release semaphore + afbClient->count--; + if (afbClient->synchronous) { + if (afbClient->verbose) printf("OnSuccessCB One Request Done\n"); + sem_post (&afbClient->semaphore); + afbClient->error=0; + } else if (afbClient->count == 0) { + if (afbClient->verbose) printf("OnSuccessCB No More Waiting Request\n"); + sem_post (&afbClient->semaphore); + } +} + +static void OnFailureCB(void* UNUSED_ARG(ctx), void* handle, const char *status, const char *info) { + + afbRequestT *afbRequest= (afbRequestT*)handle; + afbClientT *afbClient=(afbClientT*)afbRequest->afbClient; + + if (afbClient->verbose) printf("OnFailureCB callid='%s' status='%s' info='%s'\n", afbRequest->callIdTag, status, info); + + // Cancel timeout for this request + sd_event_source_unref(afbRequest->evtSource); + free(afbRequest->callIdTag); + + afbClient->error=1; + sem_post (&afbClient->semaphore); +} + + +/* the callback interface for pws */ +static struct afb_proto_ws_client_itf itf = { + .on_reply_success = OnSuccessCB, + .on_reply_fail = OnFailureCB, + .on_event_create = NULL, + .on_event_remove = NULL, + .on_event_subscribe = NULL, + .on_event_unsubscribe = NULL, + .on_event_push = OnEventCB, + .on_event_broadcast = NULL, + .on_subcall = NULL, +}; + +int OnTimeoutCB (sd_event_source* source, uint64_t timer, void* handle) { + afbClientT *afbClient= (afbClientT*)handle; + + SNDERR("\nON-TIMEOUT Call Request Fail URI=%s\n", afbClient->uri); + + // Close PCM and release waiting client + afbClient->error=1; + sem_post (&afbClient->semaphore); + + return 0; +} + +// Call AGL binder asynchronously by with a timeout +static int CallWithTimeout(afbClientT *afbClient, afbRequestT *afbRequest, int count) { + uint64_t usec; + int err; + + // create a unique tag for request + (void) asprintf(&afbRequest->callIdTag, "%d:%s", count, afbRequest->apiverb); + + // create a timer with ~250us accuracy + sd_event_now(afbClient->sdLoop, CLOCK_MONOTONIC, &usec); + sd_event_add_time(afbClient->sdLoop, &afbRequest->evtSource, CLOCK_MONOTONIC, usec+afbClient->timeout*1000, 250, OnTimeoutCB, afbClient); + + // release action is optional + if (afbRequest->apiverb) { + if (afbClient->verbose) printf("CALL-REQUEST verb=%s tag=%s\n", afbRequest->apiverb, afbRequest->callIdTag); + err = afb_proto_ws_client_call(afbClient->pws, afbRequest->apiverb, afbRequest->queryJ, afbClient->uid, afbRequest); + if (err < 0 ) goto OnErrorExit; + } + + // save client handle in request + afbRequest->afbClient = afbClient; + afbClient->count ++; + + // in synchronous mode we wait for CB to return + if (afbClient->synchronous) sem_wait(&afbClient->semaphore); + + return 0; + +OnErrorExit: + fprintf(stderr, "LaunchCallRequest: Fail call %s//%s&%s", afbClient->uri, afbRequest->apiverb, json_object_get_string(afbRequest->queryJ)); + return 1; +} + +static int LaunchCallRequest(afbClientT *afbClient, hookActionT action) { + + pthread_t tid; + int err, idx; + + switch (action) { + case HOOK_INSTALL: { + + // init waiting counting semaphore + if (sem_init(&afbClient->semaphore, 1, 0) == -1) { + fprintf(stderr, "LaunchCallRequest: Fail Semaphore Init: %s\n", afbClient->uri); + } + + // Create a main loop + err = sd_event_default(&afbClient->sdLoop); + if (err < 0) { + fprintf(stderr, "LaunchCallRequest: Connection to default event loop failed: %s\n", strerror(-err)); + goto OnErrorExit; + } + + // start a thread with a mainloop to monitor Audio-Agent + err = pthread_create(&tid, NULL, &LoopInThread, afbClient); + if (err) goto OnErrorExit; + + afbClient->pws = afb_ws_client_connect_api(afbClient->sdLoop, afbClient->uri, &itf, afbClient); + if (afbClient->pws == NULL) { + fprintf(stderr, "LaunchCallRequest: Connection to %s failed\n", afbClient->uri); + goto OnErrorExit; + } + + // register hanghup callback + afb_proto_ws_on_hangup(afbClient->pws, OnHangupCB); + + + // If no request exit now + if (!afbClient->release) { + fprintf(stderr, "LaunchCallRequest: HOOK_INSTALL:fatal mandatory request call missing in asoundrc\n"); + goto OnErrorExit;; + } + + // send call request to audio-agent asynchronously (respond with thread mainloop context) + for (idx = 0; afbClient->request[idx] != NULL; idx++) { + err = CallWithTimeout(afbClient, afbClient->request[idx], idx); + if (err) goto OnErrorExit; + } + // launch counter to keep track of waiting request call + afbClient->count=idx; + break; + } + + case HOOK_CLOSE: { + + // If no request exit now + if (!afbClient->release) { + if (afbClient->verbose) printf("LaunchCallRequest:optional HOOK_CLOSE no release control call\n"); + break; + } + + // send call request to audio-agent asynchronously (respond with thread mainloop context) + for (idx = 0; afbClient->release[idx] != NULL; idx++) { + err = CallWithTimeout(afbClient, afbClient->release[idx], idx); + if (err) goto OnErrorExit; + } + // launch counter to keep track of waiting request call + afbClient->count=idx; + break; + } + + default: + fprintf(stderr, "LaunchCallRequest (hoops): Unknown action"); + goto OnErrorExit; + } + + return 0; + +OnErrorExit: + return -1; +} + +static int AlsaCloseHook(snd_pcm_hook_t *hook) { + + afbClientT *afbClient = (afbClientT*) snd_pcm_hook_get_private (hook); + + // launch call request and create a waiting mainloop thread + int err = LaunchCallRequest(afbClient, HOOK_CLOSE); + if (err < 0) { + fprintf (stderr, "PCM Fail to Enter Mainloop\n"); + goto OnErrorExit; + } + + // wait for all call request to return + if (!afbClient->synchronous) sem_wait(&afbClient->semaphore); + if (afbClient->error) { + fprintf (stderr, "AlsaCloseHook: Notice exit before audio-4a response\n"); + goto OnErrorExit; + } + + if (afbClient->verbose) fprintf(stdout, "\nAlsaHook Close Success PCM=%s URI=%s\n", snd_pcm_name(afbClient->pcm), afbClient->uri); + return 0; + +OnErrorExit: + fprintf(stderr, "\nAlsaPcmHook Plugin Close Fail PCM=%s\n", snd_pcm_name(afbClient->pcm)); + return 0; +} + +// Get an asoundrc compound and return it as a JSON object +static json_object* AlsaGetJson (snd_config_t *ctlconfig, const char *id, const char*label) { + + json_object *queryJ; + snd_config_type_t ctype; + char* query; + + // each control is a sting that contain a json object + ctype = snd_config_get_type(ctlconfig); + snd_config_get_string(ctlconfig, (const char**) &query); + if (ctype != SND_CONFIG_TYPE_STRING) { + SNDERR("Invalid signal number for %s value=%s", label, query); + goto OnErrorExit; + } + + // cleanup string for json_tokener + for (int idx = 0; query[idx] != '\0'; idx++) { + if (query[idx] == '\'') query[idx] = '"'; + } + queryJ = json_tokener_parse(query); + if (!queryJ) { + SNDERR("Not a valid Json object control='%s' query='%s'", id, query); + goto OnErrorExit; + } + + return queryJ; + +OnErrorExit: + return NULL; +} + +static int AlsaGetActions (snd_config_t *node, afbRequestT **afbRequest, const char*id) { + const char *callConf, *apiverb; + snd_config_type_t ctype; + snd_config_iterator_t currentCall, follow; + int callCount=0; + + ctype = snd_config_get_type(node); + if (ctype != SND_CONFIG_TYPE_COMPOUND) { + snd_config_get_string(node, &callConf); + SNDERR("Invalid compound type for %s", callConf); + goto OnErrorExit; + } + + + // loop on each call + snd_config_for_each(currentCall, follow, node) { + snd_config_t *ctlconfig = snd_config_iterator_entry(currentCall); + + // ignore empty line + if (snd_config_get_id(ctlconfig, &apiverb) < 0) continue; + + // allocate an empty call request + afbRequest[callCount] = calloc(1, sizeof (afbRequestT)); + afbRequest[callCount]->apiverb=strdup(apiverb); + afbRequest[callCount]->queryJ= AlsaGetJson(ctlconfig, id, apiverb); + if (!afbRequest[callCount]->queryJ) goto OnErrorExit; + + // move to next call if any + callCount ++; + if (callCount == MAX_EVT_CALL) { + SNDERR("Too Many call MAX_EVT_CALL=%d", MAX_EVT_CALL); + goto OnErrorExit; + } + afbRequest[callCount]=NULL; // afbEvent array is NULL terminated + } + + return 0; + +OnErrorExit: + return 1; +} + +static int AlsaGetEvents (snd_config_t *node, afbEventT **afbEvent, const char*id) { + + const char *confEvents, *evtpattern; + snd_config_type_t ctype; + snd_config_iterator_t currentEvt, follow; + snd_config_t *itemConf; + int callCount=0; + int err; + + ctype = snd_config_get_type(node); + if (ctype != SND_CONFIG_TYPE_COMPOUND) { + snd_config_get_string(node, &confEvents); + SNDERR("Invalid compound type for %s", confEvents); + goto OnErrorExit; + } + + // loop on each call + snd_config_for_each(currentEvt, follow, node) { + snd_config_t *ctlconfig = snd_config_iterator_entry(currentEvt); + + // ignore empty line + if (snd_config_get_id(ctlconfig, &evtpattern) < 0) continue; + + // allocate an empty call request + afbEvent[callCount] = calloc(1, sizeof (afbEventT)); + + // extract signal num from config label + for (int idx=0; evtpattern[idx] != '\0'; idx++) { + if (evtpattern[idx]=='-' && evtpattern[idx+1] != '\0') { + int done= sscanf (&evtpattern[idx+1], "%d",&afbEvent[callCount]->signal); + if (done != 1) { + SNDERR("Invalid Signal '%s' definition should be something like Sig-xx", evtpattern); + goto OnErrorExit; + } + break; + } + } + + // extract signal key value search pattern + ctype = snd_config_get_type(ctlconfig); + if (ctype != SND_CONFIG_TYPE_COMPOUND) { + snd_config_get_string(ctlconfig, &confEvents); + SNDERR("Invalid event search pattern for %s value=%s", evtpattern, confEvents); + goto OnErrorExit; + } + + // pattern should have a search + err = snd_config_search(ctlconfig, "search", &itemConf); + if (!err) { + const char *search; + if (snd_config_get_string(itemConf, &search) < 0) { + SNDERR("Invalid event/signal 'search' should be a string %s", confEvents); + goto OnErrorExit; + } + afbEvent[callCount]->search=strdup(search); + } else { + SNDERR("Missing 'search' from event/signal 'search' from signal definition %s", confEvents); + goto OnErrorExit; + } + + // pattern should have a value + err = snd_config_search(ctlconfig, "value", &itemConf); + if (!err) { + const char *value; + if (snd_config_get_string(itemConf, &value) < 0) { + SNDERR("Invalid event/signal 'value' should be a string %s", confEvents); + goto OnErrorExit; + } + afbEvent[callCount]->value=strdup(value); + } else { + SNDERR("Missing 'value' from event/signal 'value' from signal definition %s", confEvents); + goto OnErrorExit; + } + + + // move to next call if any + callCount ++; + if (callCount == MAX_EVT_CALL) { + SNDERR("Too Many call MAX_EVT_CALL=%d", MAX_EVT_CALL); + goto OnErrorExit; + } + afbEvent[callCount]=NULL; // afbEvent array is NULL terminated + } + return 0; + +OnErrorExit: + return 1; +} + +// Function call when Plugin PCM is OPEN +int PLUGIN_ENTRY_POINT (snd_pcm_t *pcm, snd_config_t *conf) { + snd_pcm_hook_t *h_close = NULL; + snd_config_iterator_t it, next; + afbClientT *afbClient = malloc(sizeof (afbClientT)); + int err; + + // start populating client handle + afbClient->pcm = pcm; + afbClient->name= strdup(snd_pcm_name(pcm)); + afbClient->verbose = 0; + (void) asprintf(&afbClient->uid, "alsa-hook-pid:%d", getpid()); + + + // Get PCM arguments from asoundrc + snd_config_for_each(it, next, conf) { + snd_config_t *node = snd_config_iterator_entry(it); + const char *id; + + // ignore comment en empty lines + if (snd_config_get_id(node, &id) < 0) continue; + if (strcmp(id, "comment") == 0 || strcmp(id, "hint") == 0) continue; + + if (strcmp(id, "uri") == 0) { + const char *uri; + if (snd_config_get_string(node, &uri) < 0) { + SNDERR("Invalid String for %s", id); + goto OnErrorExit; + } + afbClient->uri=strdup(uri); + continue; + } + + if (strcmp(id, "verbose") == 0) { + afbClient->verbose= snd_config_get_bool(node); + if (afbClient->verbose < 0) { + SNDERR("Invalid Boolean for %s", id); + goto OnErrorExit; + } + continue; + } + + if (strcmp(id, "synchronous") == 0) { + afbClient->synchronous= snd_config_get_bool(node); + if (afbClient->synchronous < 0) { + SNDERR("Invalid Boolean for %s", id); + goto OnErrorExit; + } + continue; + } + + if (strcmp(id, "timeout") == 0) { + if (snd_config_get_integer(node, &afbClient->timeout) < 0) { + SNDERR("Invalid timeout Integer %s", id); + goto OnErrorExit; + } + continue; + } + + if (strcmp(id, "request") == 0) { + afbClient->request = malloc(MAX_API_CALL * sizeof(afbRequestT*));; + int err= AlsaGetActions(node, afbClient->request , id); + if (err) goto OnErrorExit; + continue; + } + + if (strcmp(id, "release") == 0) { + afbClient->release = malloc(MAX_API_CALL * sizeof(afbRequestT*));; + int err= AlsaGetActions(node, afbClient->release, id); + if (err) goto OnErrorExit; + continue; + } + + if (strcmp(id, "events") == 0) { + afbClient->event= malloc(MAX_API_CALL * sizeof(afbRequestT*));; + int err= AlsaGetEvents(node, afbClient->event, id); + if (err) goto OnErrorExit; + continue; + } + } + + if (afbClient->verbose) fprintf(stdout, "\nAlsaHook Install Start PCM=%s URI=%s\n", snd_pcm_name(afbClient->pcm), afbClient->uri); + + err = snd_pcm_hook_add(&h_close, afbClient->pcm, SND_PCM_HOOK_TYPE_CLOSE, AlsaCloseHook, afbClient); + if (err < 0) goto OnErrorExit; + + // launch call request and create a waiting mainloop thread + err = LaunchCallRequest(afbClient, HOOK_INSTALL); + if (err < 0) { + fprintf (stderr, "PCM Fail to Enter Mainloop\n"); + goto OnErrorExit; + } + + // wait for all call request to return + if (!afbClient->synchronous) sem_wait(&afbClient->semaphore); + if (afbClient->error) { + fprintf (stderr, "PCM Authorisation Deny from AAAA Controller (AGL Advanced Audio Agent)\n"); + goto OnErrorExit; + } + + if (afbClient->verbose) fprintf(stdout, "\nAlsaHook Install Success PCM=%s URI=%s\n", afbClient->name, afbClient->uri); + return 0; + +OnErrorExit: + fprintf(stderr, "\nAlsaPcmHook Plugin Policy Control Fail PCM=%s\n", afbClient->name); + if (h_close) + snd_pcm_hook_remove(h_close); + + return -EINVAL; +} + diff --git a/alsa-hook/README.md b/alsa-hook/README.md new file mode 100644 index 0000000..a51ec19 --- /dev/null +++ b/alsa-hook/README.md @@ -0,0 +1,211 @@ +Alsa-Hook-Plugin + +Object: Provide a Hook on Alsa PCM to check permission again AGL Advance Audio Agent +Status: Release Candidate +Author: Fulup Ar Foll fulup@iot.bzh +Date : August-2017 + References: https://www.spinics.net/lists/alsa-devel/msg54235.html + + +## Functionalities: + - Execute a set of unix/ws RPC request again AGL binders to allow/deny access + - Keep websocket open in an idependant thread in order to monitor event received from AGL audio agent + +## Installation + - Alsaplugins are typically search in /usr/share/alsa-lib. Nevertheless a full path might be given + - This plugin implement a hook on a slave PCM. Typically this slave PCM is a dedicated virtual channel (eg: navigation, emergency,...) + - Config should be place in ~/.asoundrc (see config sample in PROJECT_ROOT/conf.d/alsa) + +## Test + - Install a full .asoundrc from conf.d/project/alsa.d + - Check SoundCard ==> speaker-test -Dhw:v1340 -c2 -twav + - Check MixerPCM ==> speaker-test -DSpeakers -c2 -twav + - Check SoftVol ==> speaker-test -DMusicPCM -c2 -twav + - Check Plugin ==> speaker-test -DMultimedia -c2 -twav + - Check MultiMedia aplay -DDMyNavPCM /usr/share/sounds/alsa/test.wav + + +## Pulse audio integration + +By default Pulse only auto detect hardware sound card and virtual channel should be specified + + 1) update ~/.asoundrc file and check basic ALSA virtual channel works as expected + 2) kill/restart pulseaudio server to force alsa hookplugin loading + 3) declare alsa virtual channel as pulse sink + - pacmd load-module module-alsa-sink device=MusicPCM + - pacmd load-module module-alsa-sink device=NavPCM control=NavAlsaCtl + - pacmd list-sinks | grep -i music + 4) check your virtual pulse sink work + - paplay -d alsa_output.MusicPCM /usr/share/sounds/alsa/test.wav + - paplay -d alsa_output.NavPCM /usr/share/sounds/alsa/Front_Center.wav + +optional integration with ALSA legacy apps + + 5) start audio-pol4a controller + - repeat previous step(3) this time with device=Multimedia device=Navigation, .... + 6) check virtual channel with policy controller protection + - paplay -d alsa_output.Multimedia /usr/share/sounds/alsa/test.wav + - paplay -d alsa_output.Navigation /usr/share/sounds/alsa/Front_Center.wav + + +Bug/Feature: + 1) when softvol control is initialised from plugin and not + from AGL binding. At 1st run ctl has invalid TLV and cannot be used + Bypass Solution: + * start audio-binder before playing sound (binding create control before softvol plugin) + * run a dummy aplay -DMyNavPCM "" to get a clean control + 2) When using Audio-Pol4a to protect virtual channel, the audio policy controller should + run before adding virtual channel into pulse. + 3) In order to leverage SMACK to protect virtual audio role, a Pulse rooting plugin should be used. + + +## Alsa Config Sample + +``` +# ------------------------------------------------------ +# Mixer PCM allow to play multiple stream simultaneously +# ------------------------------------------------------ +pcm.Speakers { + type dmix + slave {pcm "hw:v1340"} #Jabra Solmate 1 + ipc_key 1001 # ipc_key should be unique to each dmix +} + +# ----------------------------------------------------- +# Register ControllerHookPlugin (ToiBeFix fullpath) +# ----------------------------------------------------- +pcm_hook_type.CtlHookPlugin { + install "AlsaInstallHook" + lib "/home/fulup/Workspace/Audio-4a/alsa-4a/build/alsa-hook/policy_alsa_hook.so" +} + + +# ------------------------------------------------------- +# Define one Audio Virtual Channel per Audio Roles +# ------------------------------------------------------- +pcm.MusicPCM { + type softvol + + # Point Slave on HOOK for policies control + slave.pcm "Speakers" + + # name should match with HAL definition + control.name "Playback Multimedia" +} + +pcm.NaviPCM { + type softvol + + # Point Slave on HOOK for policies control + slave.pcm "Speakers" + + # name should match with HAL definition + control.name "Playback Navigation" +} + +pcm.UrgentPCM { + type softvol + + # Point Slave on HOOK for policies control + slave.pcm "Speakers" + + # name should match with HAL definition + control.name "Playback Emergency" +} + +# ---------------------------------------------------- +# Define one hooked PCM channel per Audio Roles +# ---------------------------------------------------- +pcm.Multimedia { + type hooks + slave {pcm "MusicPCM"} + hooks.0 { + comment "Defined used hook sharelib and provide arguments/config to install func" + type "CtlHookPlugin" + hook_args { + + # print few log messages (default false) + verbose true + + # uri to audio-4a policy engine + uri="unix:/var/tmp/pol4a" + + # timeout in ms (default 500) + timeout 5000 + + # force API synchronous mode + synchronous true + + # api subcall to request a role + request { + multimedia-role "{'uid':'alsa-hook-client'}" + signal-timeout "{'timeout':180, 'music':'quit'}" + } + + # api subcall to request a role + release { + release-role "{'uid':'alsa-hook-client'}" + } + + # map AGL event on Unix signal. Search in event for json key=value + events { + sig-02 {search music, value quit} + sig-31 {search event, value start} + sig-32 {search event, value start} + } + } + } +} + +pcm.Navigation { + type hooks + slave {pcm "NaviPCM"} + hooks.0 { + comment "Defined used hook sharelib and provide arguments/config to install func" + type "CtlHookPlugin" + hook_args { + + # print few log messages (default false) + verbose true + + # uri to audio-4a policy engine + uri="unix:/var/tmp/pol4a" + + # timeout in ms (default 500) + timeout 5000 + + # force API synchronous mode + synchronous true + + # api subcall to request a role + request { + navigation-role "{'uid':'alsa-hook-client'}" + signal-timeout "{'timeout':5, 'navi':'quit'}" + } + + # api subcall to request a role + release { + release-role "{'uid':'alsa-hook-client'}" + } + + # map AGL event on Unix signal. Search in event for json key=value + events { + sig-02 {search navi, value quit} + sig-31 {search event, value start} + sig-32 {search event, value start} + } + } + } +} + + +``` + +NOTE: + +* Hook plugin is loaded by Alsa libasound within client context. It inherits client process attributes, as UID/GID and +SMACK label when running on AGL. The smack label is control by AGL security framework. +As a result a control request succeeds only when client application permission match requested audio role inside Cynara security database. + +* Hook plugin keep a connection with the Audio-Agent until PCM is closed by the application. This connection allow the +Audio-Agent to send events. eg: pause, quit, mute, ...
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