res_audiosocket.h File Reference

AudioSocket support functions. More...

#include <uuid/uuid.h>
#include "asterisk/frame.h"
#include "asterisk/uuid.h"

Include dependency graph for res_audiosocket.h:

This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

Enumerations
enum	ast_audiosocket_msg_kind {   AST_AUDIOSOCKET_KIND_HANGUP = 0x00 , AST_AUDIOSOCKET_KIND_UUID = 0x01 , AST_AUDIOSOCKET_KIND_DTMF = 0x03 , AST_AUDIOSOCKET_KIND_AUDIO = 0x10 ,   AST_AUDIOSOCKET_KIND_ERROR = 0xFF }

Functions
const int	ast_audiosocket_connect (const char *server, struct ast_channel *chan)
	Send the initial message to an AudioSocket server. More...
const int	ast_audiosocket_init (const int svc, const char *id)
	Send the initial message to an AudioSocket server. More...
struct ast_frame *	ast_audiosocket_receive_frame (const int svc)
	Receive an Asterisk frame from an AudioSocket server. More...
struct ast_frame *	ast_audiosocket_receive_frame_with_hangup (const int svc, int *const hangup)
	Receive an Asterisk frame from an AudioSocket server. More...
const int	ast_audiosocket_send_frame (const int svc, const struct ast_frame *f)
	Send an Asterisk audio frame to an AudioSocket server. More...

Detailed Description

AudioSocket support functions.

Author

Seán C McCord scm@c.nosp@m.ycor.nosp@m.esys..nosp@m.com

Definition in file res_audiosocket.h.

Enumeration Type Documentation

ast_audiosocket_msg_kind

enum ast_audiosocket_msg_kind

Enumerator
AST_AUDIOSOCKET_KIND_HANGUP	Message indicates the channel should be hung up, direction: Sent only.
AST_AUDIOSOCKET_KIND_UUID	Message contains the connection's UUID, direction: Received only.
AST_AUDIOSOCKET_KIND_DTMF	Message contains a DTMF digit, direction: Received only.
AST_AUDIOSOCKET_KIND_AUDIO	Messages contains audio data, direction: Sent and received.
AST_AUDIOSOCKET_KIND_ERROR	An Asterisk-side error occurred, direction: Received only.

Definition at line 40 of file res_audiosocket.h.

                              {
    /*! \brief Message indicates the channel should be hung up, direction: Sent only. */
    AST_AUDIOSOCKET_KIND_HANGUP = 0x00,
 
    /*! \brief Message contains the connection's UUID, direction: Received only. */
    AST_AUDIOSOCKET_KIND_UUID   = 0x01,
 
    /*! \brief Message contains a DTMF digit, direction: Received only. */
    AST_AUDIOSOCKET_KIND_DTMF   = 0x03,
 
    /*! \brief Messages contains audio data, direction: Sent and received. */
    AST_AUDIOSOCKET_KIND_AUDIO  = 0x10,
 
    /*! \brief An Asterisk-side error occurred, direction: Received only. */
    AST_AUDIOSOCKET_KIND_ERROR  = 0xFF,
};

Function Documentation

ast_audiosocket_connect()

const int ast_audiosocket_connect	(	const char *	server,
		struct ast_channel *	chan
	)

Send the initial message to an AudioSocket server.

Parameters

server	The server address, including port.
chan	An optional channel which will be put into autoservice during the connection period. If there is no channel to be autoserviced, pass NULL instead.

Return values

socket	file descriptor for AudioSocket on success
-1	on error

Definition at line 100 of file res_audiosocket.c.

{
    int s = -1;
    struct ast_sockaddr *addrs = NULL;
    int num_addrs = 0, i = 0;
 
    if (chan && ast_autoservice_start(chan) < 0) {
        ast_log(LOG_WARNING, "Failed to start autoservice for channel "
            "'%s'\n", ast_channel_name(chan));
        goto end;
    }
 
    if (ast_strlen_zero(server)) {
        ast_log(LOG_ERROR, "No AudioSocket server provided\n");
        goto end;
    }
 
    if (!(num_addrs = ast_sockaddr_resolve(&addrs, server, PARSE_PORT_REQUIRE,
        AST_AF_UNSPEC))) {
        ast_log(LOG_ERROR, "Failed to resolve AudioSocket service using '%s' - "
            "requires a valid hostname and port\n", server);
        goto end;
    }
 
    /* Connect to AudioSocket service */
    for (i = 0; i < num_addrs; i++) {
 
        if (!ast_sockaddr_port(&addrs[i])) {
            /* If there's no port, other addresses should have the
             * same problem. Stop here.
             */
            ast_log(LOG_ERROR, "No port provided for '%s'\n",
                ast_sockaddr_stringify(&addrs[i]));
            s = -1;
            goto end;
        }
 
        if ((s = ast_socket_nonblock(addrs[i].ss.ss_family, SOCK_STREAM,
            IPPROTO_TCP)) < 0) {
            ast_log(LOG_WARNING, "Unable to create socket: '%s'\n", strerror(errno));
            continue;
        }
 
        if (ast_connect(s, &addrs[i]) && errno == EINPROGRESS) {
 
            if (handle_audiosocket_connection(server, addrs[i], s)) {
                close(s);
                continue;
            }
 
        } else {
            ast_log(LOG_ERROR, "Connection to '%s' failed with unexpected error: %s\n",
                ast_sockaddr_stringify(&addrs[i]), strerror(errno));
            close(s);
            s = -1;
        }
 
        break;
    }
 
end:
    if (addrs) {
        ast_free(addrs);
    }
 
    if (chan && ast_autoservice_stop(chan) < 0) {
        ast_log(LOG_WARNING, "Failed to stop autoservice for channel '%s'\n",
        ast_channel_name(chan));
        close(s);
        return -1;
    }
 
    if (i == num_addrs) {
        ast_log(LOG_ERROR, "Failed to connect to AudioSocket service\n");
        close(s);
        return -1;
    }
 
    return s;
}

References AST_AF_UNSPEC, ast_autoservice_start(), ast_autoservice_stop(), ast_channel_name(), ast_connect(), ast_free, ast_log, ast_sockaddr_port, ast_sockaddr_resolve(), ast_sockaddr_stringify(), ast_socket_nonblock, ast_strlen_zero(), end, errno, handle_audiosocket_connection(), LOG_ERROR, LOG_WARNING, NULL, PARSE_PORT_REQUIRE, and ast_sockaddr::ss.

Referenced by audiosocket_exec(), and audiosocket_request().

ast_audiosocket_init()

const int ast_audiosocket_init	(	const int	svc,
		const char *	id
	)

Send the initial message to an AudioSocket server.

Parameters

svc	The file descriptor of the network socket to the AudioSocket server.
id	The UUID to send to the AudioSocket server to uniquely identify this connection.

Return values

0	on success
-1	on error

Definition at line 181 of file res_audiosocket.c.

{
    uuid_t uu;
    int ret = 0;
    uint8_t buf[3 + 16];
 
    if (ast_strlen_zero(id)) {
        ast_log(LOG_ERROR, "No UUID for AudioSocket\n");
        return -1;
    }
 
    if (uuid_parse(id, uu)) {
        ast_log(LOG_ERROR, "Failed to parse UUID '%s'\n", id);
        return -1;
    }
 
    buf[0] = AST_AUDIOSOCKET_KIND_UUID;
    buf[1] = 0x00;
    buf[2] = 0x10;
    memcpy(buf + 3, uu, 16);
 
    if (write(svc, buf, 3 + 16) != 3 + 16) {
        ast_log(LOG_WARNING, "Failed to write data to AudioSocket because: %s\n", strerror(errno));
        ret = -1;
    }
 
    return ret;
}

References AST_AUDIOSOCKET_KIND_UUID, ast_log, ast_strlen_zero(), buf, errno, LOG_ERROR, and LOG_WARNING.

Referenced by audiosocket_call(), and audiosocket_run().

ast_audiosocket_receive_frame()

struct ast_frame * ast_audiosocket_receive_frame

(

const int

svc

)

Receive an Asterisk frame from an AudioSocket server.

This returned object is a pointer to an Asterisk frame which must be manually freed by the caller.

Parameters

svc	The file descriptor of the network socket to the AudioSocket server.

Return values

A	ast_frame on success
NULL	on error

Definition at line 248 of file res_audiosocket.c.

{
    return ast_audiosocket_receive_frame_with_hangup(svc, NULL);
}

References ast_audiosocket_receive_frame_with_hangup(), and NULL.

ast_audiosocket_receive_frame_with_hangup()

struct ast_frame * ast_audiosocket_receive_frame_with_hangup	(	const int	svc,
		int *const	hangup
	)

Receive an Asterisk frame from an AudioSocket server.

This returned object is a pointer to an Asterisk frame which must be manually freed by the caller.

Parameters

svc	The file descriptor of the network socket to the AudioSocket server.
hangup	Will be true if the AudioSocket server requested the channel be hung up, otherwise false. Used as an out-parameter only, pass NULL if not needed. The function return value will always be NULL when true.

Return values

A	ast_frame on success
NULL	on error or when the hungup parameter is true.

Definition at line 253 of file res_audiosocket.c.

{
    int i = 0, n = 0, ret = 0;
    struct ast_frame f = {
        .frametype = AST_FRAME_VOICE,
        .subclass.format = ast_format_slin,
        .src = "AudioSocket",
        .mallocd = AST_MALLOCD_DATA,
    };
    uint8_t header[3];
    uint8_t *kind = &header[0];
    uint16_t *length = (uint16_t *) &header[1];
    uint8_t *data;
 
    if (hangup) {
        *hangup = 0;
    }
 
    n = read(svc, &header, 3);
    if (n == -1) {
        ast_log(LOG_WARNING, "Failed to read header from AudioSocket because: %s\n", strerror(errno));
        return NULL;
    }
 
    if (n == 0 || *kind == AST_AUDIOSOCKET_KIND_HANGUP) {
        /* Socket closure or requested hangup. */
        if (hangup) {
            *hangup = 1;
        }
        return NULL;
    }
 
    if (*kind != AST_AUDIOSOCKET_KIND_AUDIO) {
        ast_log(LOG_ERROR, "Received AudioSocket message other than hangup or audio, refer to protocol specification for valid message types\n");
        return NULL;
    }
 
    /* Swap endianess of length if needed. */
    *length = ntohs(*length);
    if (*length < 1) {
        ast_log(LOG_ERROR, "Invalid message length received from AudioSocket server. \n");
        return NULL;
    }
 
    data = ast_malloc(*length);
    if (!data) {
        ast_log(LOG_ERROR, "Failed to allocate for data from AudioSocket\n");
        return NULL;
    }
 
    ret = 0;
    n = 0;
    i = 0;
    while (i < *length) {
        n = read(svc, data + i, *length - i);
        if (n == -1) {
            ast_log(LOG_ERROR, "Failed to read payload from AudioSocket: %s\n", strerror(errno));
            ret = -1;
            break;
        }
        if (n == 0) {
            ast_log(LOG_ERROR, "Insufficient payload read from AudioSocket\n");
            ret = -1;
            break;
        }
        i += n;
    }
 
    if (ret != 0) {
        ast_free(data);
        return NULL;
    }
 
    f.data.ptr = data;
    f.datalen = *length;
    f.samples = *length / 2;
 
    /* The frame steals data, so it doesn't need to be freed here */
    return ast_frisolate(&f);
}

References AST_AUDIOSOCKET_KIND_AUDIO, AST_AUDIOSOCKET_KIND_HANGUP, ast_format_slin, AST_FRAME_VOICE, ast_free, ast_frisolate, ast_log, ast_malloc, AST_MALLOCD_DATA, ast_frame::data, ast_frame::datalen, errno, ast_frame::frametype, hangup(), LOG_ERROR, LOG_WARNING, NULL, ast_frame::ptr, and ast_frame::samples.

Referenced by ast_audiosocket_receive_frame(), audiosocket_read(), and audiosocket_run().

ast_audiosocket_send_frame()

const int ast_audiosocket_send_frame	(	const int	svc,
		const struct ast_frame *	f
	)

Send an Asterisk audio frame to an AudioSocket server.

Parameters

svc	The file descriptor of the network socket to the AudioSocket server.
f	The Asterisk audio frame to send.

Return values

0	on success
-1	on error

Definition at line 210 of file res_audiosocket.c.

{
    int datalen = f->datalen;
    if (f->frametype == AST_FRAME_DTMF) {
        datalen = 1;
    }
 
    {
        uint8_t buf[3 + datalen];
        uint16_t *length = (uint16_t *) &buf[1];
 
        /* Audio format is 16-bit, 8kHz signed linear mono for dialplan app,
            depends on agreed upon audio codec for channel driver interface. */
        switch (f->frametype) {
            case AST_FRAME_VOICE:
                buf[0] = AST_AUDIOSOCKET_KIND_AUDIO;
                *length = htons(datalen);
                memcpy(&buf[3], f->data.ptr, datalen);
                break;
            case AST_FRAME_DTMF:
                buf[0] = AST_AUDIOSOCKET_KIND_DTMF;
                buf[3] = (uint8_t) f->subclass.integer;
                *length = htons(1);
                break;
            default:
                ast_log(LOG_ERROR, "Unsupported frame type %d for AudioSocket\n", f->frametype);
                return -1;
        }
 
        if (write(svc, buf, 3 + datalen) != 3 + datalen) {
            ast_log(LOG_WARNING, "Failed to write data to AudioSocket because: %s\n", strerror(errno));
            return -1;
        }
    }
 
    return 0;
}

References AST_AUDIOSOCKET_KIND_AUDIO, AST_AUDIOSOCKET_KIND_DTMF, AST_FRAME_DTMF, AST_FRAME_VOICE, ast_log, buf, ast_frame::data, ast_frame::datalen, errno, ast_frame::frametype, ast_frame_subclass::integer, LOG_ERROR, LOG_WARNING, ast_frame::ptr, and ast_frame::subclass.

Referenced by audiosocket_run(), audiosocket_send_dtmf(), and audiosocket_write().