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-rw-r--r--Alsa-Plugin/Alsa-Policy-Hook/PolicyHookCb.c488
1 files changed, 488 insertions, 0 deletions
diff --git a/Alsa-Plugin/Alsa-Policy-Hook/PolicyHookCb.c b/Alsa-Plugin/Alsa-Policy-Hook/PolicyHookCb.c
new file mode 100644
index 0000000..ae2a5a3
--- /dev/null
+++ b/Alsa-Plugin/Alsa-Policy-Hook/PolicyHookCb.c
@@ -0,0 +1,488 @@
+/*
+ * 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 <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 <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
+
+// timeout in ms
+#define REQUEST_DEFAULT_TIMEOUT 100
+#ifndef MAINLOOP_WATCHDOG
+#define MAINLOOP_WATCHDOG 60000
+#endif
+
+// Currently not implemented
+#define UNUSED(x) UNUSED_ ## x __attribute__((__unused__))
+#define UNUSED_FUNCTION(x) __attribute__((__unused__)) UNUSED_ ## x
+void OnRequestCB(void* UNUSED(handle) , const char* UNUSED(api), const char* UNUSED(verb), struct afb_wsj1_msg*UNUSED(msg)) {}
+
+ typedef struct {
+ snd_pcm_t *pcm;
+ const char *uri;
+ struct afb_wsj1 *wsj1;
+ sd_event *sdLoop;
+ int verbose;
+ sem_t semaphore;
+ int count;
+ int error;
+} afbClientT;
+
+typedef struct {
+ const char *api;
+ const char *verb;
+ long timeout;
+ char *query;
+
+ sd_event_source *evtSource;
+ char *callIdTag;
+ afbClientT *afbClient;
+} afbRequestT;
+
+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 Active count=%d\n", count++);
+ sd_event_run(afbClient->sdLoop, watchdog);
+ }
+
+ return NULL;
+}
+
+// lost connect with the AudioDaemon
+static void OnHangupCB(void *handle, struct afb_wsj1 *wsj1) {
+
+ 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);
+}
+
+// supported action
+typedef enum {
+ ACTION_PAUSE,
+ ACTION_START,
+ ACTION_STOP,
+ ACTION_RESUME,
+
+ ACTION_NONE
+} evtActionEnumT;
+
+// action label/enum map
+const char *evtActionLabels[] ={
+ [ACTION_PAUSE] = "pause",
+ [ACTION_START] = "start",
+ [ACTION_STOP] = "stop",
+ [ACTION_RESUME]= "resume",
+
+ [ACTION_NONE]=NULL
+};
+
+static evtActionEnumT getActionEnum (const char *label) {
+ int idx;
+
+ if (!label) return ACTION_NONE;
+
+ for (idx = 0; evtActionLabels[idx] != NULL; idx++) {
+ if (! strcmp(evtActionLabels[idx], label)) break;
+ }
+
+ if (evtActionLabels[idx]) return idx;
+ else return ACTION_NONE;
+}
+
+void OnEventCB(void *handle, const char *event, struct afb_wsj1_msg *msg) {
+ afbClientT *afbClient = (afbClientT*) handle;
+ json_object *eventJ, *tmpJ, *dataJ;
+ const char *action;
+ int err, value, done;
+
+
+ eventJ = afb_wsj1_msg_object_j(msg);
+ done= json_object_object_get_ex(eventJ,"data", &dataJ);
+ if (!done) {
+ SNDERR ("PCM_HOOK: uri=%s empty event action", afbClient->uri);
+ goto OnErrorExit;
+ }
+
+ json_object_object_get_ex(dataJ,"action", &tmpJ);
+ action=json_object_get_string(tmpJ);
+
+ json_object_object_get_ex(dataJ,"value", &tmpJ);
+ value=json_object_get_int(tmpJ);
+
+ switch (getActionEnum(action)) {
+ case ACTION_PAUSE:
+ err = snd_pcm_pause (afbClient->pcm, value);
+ if (err < 0) SNDERR ("PCM_HOOK: Fail to pause value=%d\n", value);
+ break;
+
+ case ACTION_STOP:
+ err = snd_pcm_drop (afbClient->pcm);
+ if (err < 0) SNDERR ("PCM_HOOK: Fail to close\n");
+ break;
+
+ case ACTION_START:
+ err = snd_pcm_resume (afbClient->pcm);
+ if (err < 0) SNDERR ("PCM_HOOK: Fail to start\n");
+ break;
+
+ default:
+ SNDERR ("PCM_HOOK: Unsupported Event uri=%s action=%s", afbClient->uri, action);
+ goto OnErrorExit;
+ }
+
+ if (afbClient->verbose) printf("ON-EVENT action=%s value=%d\n", action, value);
+ return;
+
+OnErrorExit:
+ SNDERR("ON-EVENT %s(%s)\n", event, afb_wsj1_msg_object_s(msg));
+ return;
+}
+
+// callback interface for wsj1
+static struct afb_wsj1_itf itf = {
+ .on_hangup = OnHangupCB,
+ .on_call = OnRequestCB,
+ .on_event = OnEventCB
+};
+
+void OnResponseCB(void *handle, struct afb_wsj1_msg *msg) {
+ afbRequestT *afbRequest= (afbRequestT*)handle;
+
+ if (afbRequest->afbClient->verbose) printf("ON-RESPONSE call=%s response=%s\n", afbRequest->callIdTag, afb_wsj1_msg_object_s(msg));
+
+ // Cancel timeout for this request
+ sd_event_source_unref(afbRequest->evtSource);
+
+ if (! afb_wsj1_msg_is_reply_ok(msg)) goto OnErrorExit;
+
+ // When not more waiting call release semaphore
+ afbRequest->afbClient->count--;
+ if (afbRequest->afbClient->count == 0) {
+ if (afbRequest->afbClient->verbose) printf("ON-RESPONSE No More Waiting Request\n");
+ afbRequest->afbClient->error=0;
+ sem_post (&afbRequest->afbClient->semaphore);
+ }
+ return;
+
+OnErrorExit:
+ fprintf(stderr, "ON-RESPONSE ERROR call=%s response=%s\n", afbRequest->callIdTag, afb_wsj1_msg_object_s(msg));
+ afbRequest->afbClient->error=1;
+ sem_post (&afbRequest->afbClient->semaphore);
+}
+
+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/%s", count, afbRequest->api, afbRequest->verb);
+
+ // 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+afbRequest->timeout*1000, 250, OnTimeoutCB, afbClient);
+
+ err = afb_wsj1_call_s(afbClient->wsj1, afbRequest->api, afbRequest->verb, afbRequest->query, OnResponseCB, afbRequest);
+ if (err) goto OnErrorExit;
+
+ // save client handle in request
+ afbRequest->afbClient = afbClient;
+ afbClient->count ++;
+
+ return 0;
+
+OnErrorExit:
+ return -1;
+}
+
+static int LaunchCallRequest(afbClientT *afbClient, afbRequestT **afbRequest) {
+
+ pthread_t tid;
+ int err, idx;
+
+ // 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;
+
+ // connect the websocket wsj1 to the uri given by the first argument
+ afbClient->wsj1 = afb_ws_client_connect_wsj1(afbClient->sdLoop, afbClient->uri, &itf, afbClient);
+ if (afbClient->wsj1 == NULL) {
+ fprintf(stderr, "LaunchCallRequest: Connection to %s failed\n", afbClient->uri);
+ goto OnErrorExit;
+ }
+
+ // send call request to audio-agent asynchronously (respond with thread mainloop context)
+ for (idx = 0; afbRequest[idx] != NULL; idx++) {
+ err = CallWithTimeout(afbClient, afbRequest[idx], idx);
+ if (err) {
+ fprintf(stderr, "LaunchCallRequest: Fail call %s//%s/%s&%s", afbClient->uri, afbRequest[idx]->api, afbRequest[idx]->verb, afbRequest[idx]->query);
+ goto OnErrorExit;
+ }
+ }
+
+ // launch counter to keep track of waiting request call
+ afbClient->count=idx;
+
+ return 0;
+
+OnErrorExit:
+ return -1;
+}
+
+static int AlsaCloseHook(snd_pcm_hook_t *hook) {
+
+ afbClientT *afbClient = (afbClientT*) snd_pcm_hook_get_private (hook);
+
+ if (afbClient->verbose) fprintf(stdout, "\nAlsaCloseHook pcm=%s\n", snd_pcm_name(afbClient->pcm));
+ return 0;
+}
+
+// Function call when Plugin PCM is OPEN
+int PLUGIN_ENTRY_POINT (snd_pcm_t *pcm, snd_config_t *conf) {
+ afbRequestT **afbRequest;
+ snd_pcm_hook_t *h_close = NULL;
+ snd_config_iterator_t it, next;
+ afbClientT *afbClient = malloc(sizeof (afbClientT));
+ afbRequest = malloc(MAX_API_CALL * sizeof (afbRequestT));
+ int err;
+
+ // start populating client handle
+ afbClient->pcm = pcm;
+ afbClient->verbose = 0;
+
+
+ // 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, "request") == 0) {
+ const char *callConf, *callLabel;
+ snd_config_type_t ctype;
+ snd_config_iterator_t currentCall, follow;
+ snd_config_t *itemConf;
+ 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, &callLabel) < 0) continue;
+
+ // each clt should be a valid config compound
+ ctype = snd_config_get_type(ctlconfig);
+ if (ctype != SND_CONFIG_TYPE_COMPOUND) {
+ snd_config_get_string(node, &callConf);
+ SNDERR("Invalid call element for %s", callLabel);
+ goto OnErrorExit;
+ }
+
+ // allocate an empty call request
+ afbRequest[callCount] = calloc(1, sizeof (afbRequestT));
+
+
+ err = snd_config_search(ctlconfig, "api", &itemConf);
+ if (!err) {
+ if (snd_config_get_string(itemConf, &afbRequest[callCount]->api) < 0) {
+ SNDERR("Invalid api string for %s", callLabel);
+ goto OnErrorExit;
+ }
+ }
+
+ err = snd_config_search(ctlconfig, "verb", &itemConf);
+ if (!err) {
+ if (snd_config_get_string(itemConf, &afbRequest[callCount]->verb) < 0) {
+ SNDERR("Invalid verb string %s", id);
+ goto OnErrorExit;
+ }
+ }
+
+ err = snd_config_search(ctlconfig, "timeout", &itemConf);
+ if (!err) {
+ if (snd_config_get_integer(itemConf, &afbRequest[callCount]->timeout) < 0) {
+ SNDERR("Invalid timeout Integer %s", id);
+ goto OnErrorExit;
+ }
+ }
+
+ err = snd_config_search(ctlconfig, "query", &itemConf);
+ if (!err) {
+ const char *query;
+ if (snd_config_get_string(itemConf, &query) < 0) {
+ SNDERR("Invalid query string %s", id);
+ goto OnErrorExit;
+ }
+ // cleanup string for json_tokener
+ afbRequest[callCount]->query = strdup(query);
+ for (int idx = 0; query[idx] != '\0'; idx++) {
+ if (query[idx] == '\'') afbRequest[callCount]->query[idx] = '"';
+ else afbRequest[callCount]->query[idx] = query[idx];
+ }
+ json_object *queryJ = json_tokener_parse(query);
+ if (!queryJ) {
+ SNDERR("Invalid Json %s query=%s format \"{'tok1':'val1', 'tok2':'val2'}\" ", id, query);
+ goto OnErrorExit;
+ }
+ }
+
+ // Simple check on call request validity
+ if (!afbRequest[callCount]->query) afbRequest[callCount]->query= "";
+ if (!afbRequest[callCount]->timeout) afbRequest[callCount]->timeout=REQUEST_DEFAULT_TIMEOUT ;
+ if (!afbRequest[callCount]->verb || !afbRequest[callCount]->api) {
+ SNDERR("Missing api/verb %s in asoundrc", callLabel);
+ goto OnErrorExit;
+ }
+
+ // move to next call if any
+ callCount ++;
+ if (callCount == MAX_API_CALL) {
+ SNDERR("Too Many call MAX_API_CALL=%d", MAX_API_CALL);
+ goto OnErrorExit;
+ }
+ afbRequest[callCount]=NULL; // afbRequest array is NULL terminated
+
+ }
+ 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, afbRequest);
+ if (err < 0) {
+ fprintf (stderr, "PCM Fail to Enter Mainloop\n");
+ goto OnErrorExit;
+ }
+
+ // wait for all call request to return
+ sem_wait(&afbClient->semaphore);
+ if (afbClient->error) {
+ fprintf (stderr, "PCM Authorisation from Audio Agent Refused\n");
+ goto OnErrorExit;
+ }
+
+ if (afbClient->verbose) fprintf(stdout, "\nAlsaHook Install Success PCM=%s URI=%s\n", snd_pcm_name(afbClient->pcm), afbClient->uri);
+ return 0;
+
+OnErrorExit:
+ fprintf(stderr, "\nAlsaPcmHook Plugin Install Fail PCM=%s\n", snd_pcm_name(afbClient->pcm));
+ if (h_close)
+ snd_pcm_hook_remove(h_close);
+
+ return -EINVAL;
+}
+