Wed Jan 8 2020 09:49:44

Asterisk developer's documentation


chan_nbs.c
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1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2006, Digium, Inc.
5  *
6  * Mark Spencer <markster@digium.com>
7  *
8  * See http://www.asterisk.org for more information about
9  * the Asterisk project. Please do not directly contact
10  * any of the maintainers of this project for assistance;
11  * the project provides a web site, mailing lists and IRC
12  * channels for your use.
13  *
14  * This program is free software, distributed under the terms of
15  * the GNU General Public License Version 2. See the LICENSE file
16  * at the top of the source tree.
17  */
18 
19 /*! \file
20  *
21  * \brief Network broadcast sound support channel driver
22  *
23  * \author Mark Spencer <markster@digium.com>
24  *
25  * \ingroup channel_drivers
26  */
27 
28 /*** MODULEINFO
29  <depend>nbs</depend>
30  <support_level>extended</support_level>
31  ***/
32 
33 #include "asterisk.h"
34 
35 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 328209 $")
36 
37 #include <sys/socket.h>
38 #include <sys/time.h>
39 #include <arpa/inet.h>
40 #include <fcntl.h>
41 #include <sys/ioctl.h>
42 #include <nbs.h>
43 
44 #include "asterisk/lock.h"
45 #include "asterisk/channel.h"
46 #include "asterisk/config.h"
47 #include "asterisk/module.h"
48 #include "asterisk/pbx.h"
49 #include "asterisk/utils.h"
50 
51 static const char tdesc[] = "Network Broadcast Sound Driver";
52 
53 /* Only linear is allowed */
55 
56 static char context[AST_MAX_EXTENSION] = "default";
57 static const char type[] = "NBS";
58 
59 /* NBS creates private structures on demand */
60 
61 struct nbs_pvt {
62  NBS *nbs;
63  struct ast_channel *owner; /* Channel we belong to, possibly NULL */
64  char app[16]; /* Our app */
65  char stream[80]; /* Our stream */
66  struct ast_frame fr; /* "null" frame */
67  struct ast_module_user *u; /*! for holding a reference to this module */
68 };
69 
70 static struct ast_channel *nbs_request(const char *type, format_t format, const struct ast_channel *requestor, void *data, int *cause);
71 static int nbs_call(struct ast_channel *ast, char *dest, int timeout);
72 static int nbs_hangup(struct ast_channel *ast);
73 static struct ast_frame *nbs_xread(struct ast_channel *ast);
74 static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame);
75 
76 static const struct ast_channel_tech nbs_tech = {
77  .type = type,
78  .description = tdesc,
79  .capabilities = AST_FORMAT_SLINEAR,
80  .requester = nbs_request,
81  .call = nbs_call,
82  .hangup = nbs_hangup,
83  .read = nbs_xread,
84  .write = nbs_xwrite,
85 };
86 
87 static int nbs_call(struct ast_channel *ast, char *dest, int timeout)
88 {
89  struct nbs_pvt *p;
90 
91  p = ast->tech_pvt;
92 
93  if ((ast->_state != AST_STATE_DOWN) && (ast->_state != AST_STATE_RESERVED)) {
94  ast_log(LOG_WARNING, "nbs_call called on %s, neither down nor reserved\n", ast->name);
95  return -1;
96  }
97  /* When we call, it just works, really, there's no destination... Just
98  ring the phone and wait for someone to answer */
99  ast_debug(1, "Calling %s on %s\n", dest, ast->name);
100 
101  /* If we can't connect, return congestion */
102  if (nbs_connect(p->nbs)) {
103  ast_log(LOG_WARNING, "NBS Connection failed on %s\n", ast->name);
105  } else {
108  }
109 
110  return 0;
111 }
112 
113 static void nbs_destroy(struct nbs_pvt *p)
114 {
115  if (p->nbs)
116  nbs_delstream(p->nbs);
118  ast_free(p);
119 }
120 
121 static struct nbs_pvt *nbs_alloc(void *data)
122 {
123  struct nbs_pvt *p;
124  int flags = 0;
125  char stream[256];
126  char *opts;
127 
128  ast_copy_string(stream, data, sizeof(stream));
129  if ((opts = strchr(stream, ':'))) {
130  *opts = '\0';
131  opts++;
132  } else
133  opts = "";
134  p = ast_calloc(1, sizeof(*p));
135  if (p) {
136  if (!ast_strlen_zero(opts)) {
137  if (strchr(opts, 'm'))
138  flags |= NBS_FLAG_MUTE;
139  if (strchr(opts, 'o'))
140  flags |= NBS_FLAG_OVERSPEAK;
141  if (strchr(opts, 'e'))
142  flags |= NBS_FLAG_EMERGENCY;
143  if (strchr(opts, 'O'))
144  flags |= NBS_FLAG_OVERRIDE;
145  } else
146  flags = NBS_FLAG_OVERSPEAK;
147 
148  ast_copy_string(p->stream, stream, sizeof(p->stream));
149  p->nbs = nbs_newstream("asterisk", stream, flags);
150  if (!p->nbs) {
151  ast_log(LOG_WARNING, "Unable to allocate new NBS stream '%s' with flags %d\n", stream, flags);
152  ast_free(p);
153  p = NULL;
154  } else {
155  /* Set for 8000 hz mono, 640 samples */
156  nbs_setbitrate(p->nbs, 8000);
157  nbs_setchannels(p->nbs, 1);
158  nbs_setblocksize(p->nbs, 640);
159  nbs_setblocking(p->nbs, 0);
160  }
161  }
162  return p;
163 }
164 
165 static int nbs_hangup(struct ast_channel *ast)
166 {
167  struct nbs_pvt *p;
168  p = ast->tech_pvt;
169  ast_debug(1, "nbs_hangup(%s)\n", ast->name);
170  if (!ast->tech_pvt) {
171  ast_log(LOG_WARNING, "Asked to hangup channel not connected\n");
172  return 0;
173  }
174  nbs_destroy(p);
175  ast->tech_pvt = NULL;
177  return 0;
178 }
179 
180 static struct ast_frame *nbs_xread(struct ast_channel *ast)
181 {
182  struct nbs_pvt *p = ast->tech_pvt;
183 
184 
185  /* Some nice norms */
186  p->fr.datalen = 0;
187  p->fr.samples = 0;
188  p->fr.data.ptr = NULL;
189  p->fr.src = type;
190  p->fr.offset = 0;
191  p->fr.mallocd=0;
192  p->fr.delivery.tv_sec = 0;
193  p->fr.delivery.tv_usec = 0;
194 
195  ast_debug(1, "Returning null frame on %s\n", ast->name);
196 
197  return &p->fr;
198 }
199 
200 static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame)
201 {
202  struct nbs_pvt *p = ast->tech_pvt;
203  /* Write a frame of (presumably voice) data */
204  if (frame->frametype != AST_FRAME_VOICE) {
205  if (frame->frametype != AST_FRAME_IMAGE)
206  ast_log(LOG_WARNING, "Don't know what to do with frame type '%d'\n", frame->frametype);
207  return 0;
208  }
209  if (!(frame->subclass.codec &
210  (AST_FORMAT_SLINEAR))) {
211  ast_log(LOG_WARNING, "Cannot handle frames in %s format\n", ast_getformatname(frame->subclass.codec));
212  return 0;
213  }
214  if (ast->_state != AST_STATE_UP) {
215  /* Don't try tos end audio on-hook */
216  return 0;
217  }
218  if (nbs_write(p->nbs, frame->data.ptr, frame->datalen / 2) < 0)
219  return -1;
220  return 0;
221 }
222 
223 static struct ast_channel *nbs_new(struct nbs_pvt *i, int state, const char *linkedid)
224 {
225  struct ast_channel *tmp;
226  tmp = ast_channel_alloc(1, state, 0, 0, "", "s", context, linkedid, 0, "NBS/%s", i->stream);
227  if (tmp) {
228  tmp->tech = &nbs_tech;
229  ast_channel_set_fd(tmp, 0, nbs_fd(i->nbs));
230  tmp->nativeformats = prefformat;
231  tmp->rawreadformat = prefformat;
232  tmp->rawwriteformat = prefformat;
233  tmp->writeformat = prefformat;
234  tmp->readformat = prefformat;
235  if (state == AST_STATE_RING)
236  tmp->rings = 1;
237  tmp->tech_pvt = i;
238  ast_copy_string(tmp->context, context, sizeof(tmp->context));
239  ast_copy_string(tmp->exten, "s", sizeof(tmp->exten));
240  ast_string_field_set(tmp, language, "");
241  i->owner = tmp;
242  i->u = ast_module_user_add(tmp);
243  if (state != AST_STATE_DOWN) {
244  if (ast_pbx_start(tmp)) {
245  ast_log(LOG_WARNING, "Unable to start PBX on %s\n", tmp->name);
246  ast_hangup(tmp);
247  }
248  }
249  } else
250  ast_log(LOG_WARNING, "Unable to allocate channel structure\n");
251  return tmp;
252 }
253 
254 
255 static struct ast_channel *nbs_request(const char *type, format_t format, const struct ast_channel *requestor, void *data, int *cause)
256 {
257  format_t oldformat;
258  struct nbs_pvt *p;
259  struct ast_channel *tmp = NULL;
260 
261  oldformat = format;
262  format &= (AST_FORMAT_SLINEAR);
263  if (!format) {
264  ast_log(LOG_NOTICE, "Asked to get a channel of unsupported format '%s'\n", ast_getformatname(oldformat));
265  return NULL;
266  }
267  p = nbs_alloc(data);
268  if (p) {
269  tmp = nbs_new(p, AST_STATE_DOWN, requestor ? requestor->linkedid : NULL);
270  if (!tmp)
271  nbs_destroy(p);
272  }
273  return tmp;
274 }
275 
276 static int unload_module(void)
277 {
278  /* First, take us out of the channel loop */
279  ast_channel_unregister(&nbs_tech);
280  return 0;
281 }
282 
283 static int load_module(void)
284 {
285  /* Make sure we can register our channel type */
286  if (ast_channel_register(&nbs_tech)) {
287  ast_log(LOG_ERROR, "Unable to register channel class %s\n", type);
288  return -1;
289  }
290  return 0;
291 }
292 
293 AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "Network Broadcast Sound Support");
union ast_frame_subclass subclass
Definition: frame.h:146
int ast_hangup(struct ast_channel *chan)
Hang up a channel.
Definition: channel.c:2804
Main Channel structure associated with a channel.
Definition: channel.h:742
#define AST_MODULE_INFO_STANDARD(keystr, desc)
Definition: module.h:396
static int unload_module(void)
Definition: chan_nbs.c:276
const char *const type
Definition: channel.h:508
static struct ast_channel_tech nbs_tech
Definition: chan_nbs.c:76
Asterisk locking-related definitions:
Asterisk main include file. File version handling, generic pbx functions.
int rings
Definition: channel.h:840
static format_t prefformat
Definition: chan_nbs.c:54
static int nbs_hangup(struct ast_channel *ast)
Definition: chan_nbs.c:165
int offset
Definition: frame.h:156
int ast_queue_control(struct ast_channel *chan, enum ast_control_frame_type control)
Queue a control frame with payload.
Definition: channel.c:1601
format_t writeformat
Definition: channel.h:854
void ast_channel_unregister(const struct ast_channel_tech *tech)
Unregister a channel technology.
Definition: channel.c:938
void * ptr
Definition: frame.h:160
void * tech_pvt
Definition: channel.h:744
char context[AST_MAX_CONTEXT]
Definition: channel.h:868
#define LOG_WARNING
Definition: logger.h:144
enum ast_pbx_result ast_pbx_start(struct ast_channel *c)
Create a new thread and start the PBX.
Definition: pbx.c:5879
format_t rawwriteformat
Definition: channel.h:856
Configuration File Parser.
NBS * nbs
Definition: chan_nbs.c:62
int ast_channel_register(const struct ast_channel_tech *tech)
Register a channel technology (a new channel driver) Called by a channel module to register the kind ...
Definition: channel.c:907
format_t nativeformats
Definition: channel.h:852
static struct nbs_pvt * nbs_alloc(void *data)
Definition: chan_nbs.c:121
static struct ast_channel * nbs_new(struct nbs_pvt *i, int state, const char *linkedid)
Definition: chan_nbs.c:223
format_t codec
Definition: frame.h:137
const char * data
Definition: channel.h:755
const ast_string_field linkedid
Definition: channel.h:787
#define ast_module_user_remove(user)
Definition: module.h:269
format_t rawreadformat
Definition: channel.h:855
static struct ast_frame * nbs_xread(struct ast_channel *ast)
Definition: chan_nbs.c:180
struct ast_channel * ast_channel_alloc(int needqueue, int state, const char *cid_num, const char *cid_name, const char *acctcode, const char *exten, const char *context, const char *linkedid, const int amaflag, const char *name_fmt,...)
Definition: channel.c:9825
Utility functions.
#define ast_debug(level,...)
Log a DEBUG message.
Definition: logger.h:236
General Asterisk PBX channel definitions.
const char * src
Definition: frame.h:158
static force_inline int attribute_pure ast_strlen_zero(const char *s)
Definition: strings.h:63
#define AST_MAX_EXTENSION
Definition: channel.h:135
int datalen
Definition: frame.h:148
static char language[MAX_LANGUAGE]
Definition: chan_alsa.c:108
#define ast_module_user_add(chan)
Definition: module.h:268
Structure to describe a channel &quot;technology&quot;, ie a channel driver See for examples: ...
Definition: channel.h:507
Core PBX routines and definitions.
char * ast_getformatname(format_t format)
Get the name of a format.
Definition: frame.c:578
#define LOG_ERROR
Definition: logger.h:155
char app[16]
Definition: chan_nbs.c:64
int64_t format_t
Definition: frame_defs.h:32
static int nbs_xwrite(struct ast_channel *ast, struct ast_frame *frame)
Definition: chan_nbs.c:200
enum ast_channel_state _state
Definition: channel.h:839
const ast_string_field name
Definition: channel.h:787
void ast_log(int level, const char *file, int line, const char *function, const char *fmt,...)
Used for sending a log message This is the standard logger function. Probably the only way you will i...
Definition: logger.c:1207
#define LOG_NOTICE
Definition: logger.h:133
static int nbs_call(struct ast_channel *ast, char *dest, int timeout)
Definition: chan_nbs.c:87
static const char tdesc[]
Definition: chan_nbs.c:51
#define ast_free(a)
Definition: astmm.h:97
struct ast_module_user * u
Definition: chan_nbs.c:67
static const char type[]
Definition: chan_nbs.c:57
void ast_channel_set_fd(struct ast_channel *chan, int which, int fd)
Definition: channel.c:2631
struct timeval delivery
Definition: frame.h:162
int mallocd
Definition: frame.h:152
struct ast_frame fr
Definition: chan_nbs.c:66
static char context[AST_MAX_EXTENSION]
Definition: chan_nbs.c:56
#define AST_FORMAT_SLINEAR
Definition: frame.h:254
format_t readformat
Definition: channel.h:853
#define ast_calloc(a, b)
Definition: astmm.h:82
void ast_copy_string(char *dst, const char *src, size_t size)
Size-limited null-terminating string copy.
Definition: strings.h:223
int ast_setstate(struct ast_channel *chan, enum ast_channel_state)
Change the state of a channel.
Definition: channel.c:7119
Data structure associated with a single frame of data.
Definition: frame.h:142
static int load_module(void)
Definition: chan_nbs.c:283
char stream[80]
Definition: chan_nbs.c:65
enum ast_frame_type frametype
Definition: frame.h:144
static struct ast_channel * nbs_request(const char *type, format_t format, const struct ast_channel *requestor, void *data, int *cause)
Definition: chan_nbs.c:255
#define ASTERISK_GPL_KEY
The text the key() function should return.
Definition: module.h:38
Asterisk module definitions.
static snd_pcm_format_t format
Definition: chan_alsa.c:93
union ast_frame::@172 data
struct ast_channel_tech * tech
Definition: channel.h:743
char exten[AST_MAX_EXTENSION]
Definition: channel.h:869
struct ast_channel * owner
Definition: chan_nbs.c:63
#define ASTERISK_FILE_VERSION(file, version)
Register/unregister a source code file with the core.
Definition: asterisk.h:180
int samples
Definition: frame.h:150
#define ast_string_field_set(x, field, data)
Set a field to a simple string value.
Definition: stringfields.h:344
static void nbs_destroy(struct nbs_pvt *p)
Definition: chan_nbs.c:113