res/res_fax_spandsp.c

   1 /*
   2  * Asterisk -- An open source telephony toolkit.
   3  *
   4  * Copyright (C) 2009-2010, Digium, Inc.
   5  *
   6  * Matthew Nicholson <mnicholson@digium.com>
   7  *
   8  * Initial T.38-gateway code
   9  * 2008, Daniel Ferenci <daniel.ferenci@nethemba.com>
  10  * Created by Nethemba s.r.o. http://www.nethemba.com
  11  * Sponsored by IPEX a.s. http://www.ipex.cz
  12  *
  13  * T.38-gateway integration into asterisk app_fax and rework
  14  * 2008, Gregory Hinton Nietsky <gregory@dnstelecom.co.za>
  15  * dns Telecom http://www.dnstelecom.co.za
  16  *
  17  * Modified to make T.38-gateway compatible with Asterisk 1.6.2
  18  * 2010, Anton Verevkin <mymail@verevkin.it>
  19  * ViaNetTV http://www.vianettv.com
  20  *
  21  * Modified to make T.38-gateway work
  22  * 2010, Klaus Darilion, IPCom GmbH, www.ipcom.at
  23  *
  24  * See http://www.asterisk.org for more information about
  25  * the Asterisk project. Please do not directly contact
  26  * any of the maintainers of this project for assistance;
  27  * the project provides a web site, mailing lists and IRC
  28  * channels for your use.
  29  *
  30  * This program is free software, distributed under the terms of
  31  * the GNU General Public License Version 2. See the LICENSE file
  32  * at the top of the source tree.
  33  */
  34
  35 /*! \file
  36  *
  37  * \brief Spandsp T.38 and G.711 FAX Resource
  38  *
  39  * \author Matthew Nicholson <mnicholson@digium.com>
  40  *
  41  * This module registers the Spandsp FAX technology with the res_fax module.
  42  */
  43
  44 /*** MODULEINFO
  45         <depend>spandsp</depend>
  46         <depend>res_fax</depend>
  47 ***/
  48
  49 #include "asterisk.h"
  50
  51 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
  52
  53 #define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
  54 #include <spandsp.h>
  55 #include <spandsp/version.h>
  56
  57 #include "asterisk/logger.h"
  58 #include "asterisk/module.h"
  59 #include "asterisk/strings.h"
  60 #include "asterisk/cli.h"
  61 #include "asterisk/utils.h"
  62 #include "asterisk/timing.h"
  63 #include "asterisk/astobj2.h"
  64 #include "asterisk/res_fax.h"
  65 #include "asterisk/channel.h"
  66
  67 #define SPANDSP_FAX_SAMPLES 160
  68 #define SPANDSP_FAX_TIMER_RATE 8000 / SPANDSP_FAX_SAMPLES       /* 50 ticks per second, 20ms, 160 samples per second */
  69 #define SPANDSP_ENGAGE_UDPTL_NAT_RETRY 3
  70
  71 static void *spandsp_fax_new(struct ast_fax_session *s, struct ast_fax_tech_token *token);
  72 static void spandsp_fax_destroy(struct ast_fax_session *s);
  73 static struct ast_frame *spandsp_fax_read(struct ast_fax_session *s);
  74 static int spandsp_fax_write(struct ast_fax_session *s, const struct ast_frame *f);
  75 static int spandsp_fax_start(struct ast_fax_session *s);
  76 static int spandsp_fax_cancel(struct ast_fax_session *s);
  77 static int spandsp_fax_switch_to_t38(struct ast_fax_session *s);
  78 static int spandsp_fax_gateway_start(struct ast_fax_session *s);
  79 static int spandsp_fax_gateway_process(struct ast_fax_session *s, const struct ast_frame *f);
  80 static void spandsp_fax_gateway_cleanup(struct ast_fax_session *s);
  81
  82 static char *spandsp_fax_cli_show_capabilities(int fd);
  83 static char *spandsp_fax_cli_show_session(struct ast_fax_session *s, int fd);
  84 static char *spandsp_fax_cli_show_stats(int fd);
  85 static char *spandsp_fax_cli_show_settings(int fd);
  86
  87 static struct ast_fax_tech spandsp_fax_tech = {
  88         .type = "Spandsp",
  89         .description = "Spandsp FAX Driver",
  90 #if SPANDSP_RELEASE_DATE >= 20090220
  91         /* spandsp 0.0.6 */
  92         .version = SPANDSP_RELEASE_DATETIME_STRING,
  93 #else
  94         /* spandsp 0.0.5
  95          * TODO: maybe we should determine the version better way
  96          */
  97         .version = "pre-20090220",
  98 #endif
  99         .caps = AST_FAX_TECH_AUDIO | AST_FAX_TECH_T38 | AST_FAX_TECH_SEND | AST_FAX_TECH_RECEIVE | AST_FAX_TECH_GATEWAY,
 100         .new_session = spandsp_fax_new,
 101         .destroy_session = spandsp_fax_destroy,
 102         .read = spandsp_fax_read,
 103         .write = spandsp_fax_write,
 104         .start_session = spandsp_fax_start,
 105         .cancel_session = spandsp_fax_cancel,
 106         .switch_to_t38 = spandsp_fax_switch_to_t38,
 107         .cli_show_capabilities = spandsp_fax_cli_show_capabilities,
 108         .cli_show_session = spandsp_fax_cli_show_session,
 109         .cli_show_stats = spandsp_fax_cli_show_stats,
 110         .cli_show_settings = spandsp_fax_cli_show_settings,
 111 };
 112
 113 struct spandsp_fax_stats {
 114         int success;
 115         int nofax;
 116         int neg_failed;
 117         int failed_to_train;
 118         int rx_protocol_error;
 119         int tx_protocol_error;
 120         int protocol_error;
 121         int retries_exceeded;
 122         int file_error;
 123         int mem_error;
 124         int call_dropped;
 125         int unknown_error;
 126         int switched;
 127 };
 128
 129 static struct {
 130         ast_mutex_t lock;
 131         struct spandsp_fax_stats g711;
 132         struct spandsp_fax_stats t38;
 133 } spandsp_global_stats;
 134
 135 struct spandsp_pvt {
 136         unsigned int ist38:1;
 137         unsigned int isdone:1;
 138         enum ast_t38_state ast_t38_state;
 139         fax_state_t fax_state;
 140         t38_terminal_state_t t38_state;
 141         t30_state_t *t30_state;
 142         t38_core_state_t *t38_core_state;
 143
 144         struct spandsp_fax_stats *stats;
 145
 146         struct spandsp_fax_gw_stats *t38stats;
 147         t38_gateway_state_t t38_gw_state;
 148
 149         struct ast_timer *timer;
 150         AST_LIST_HEAD(frame_queue, ast_frame) read_frames;
 151 };
 152
 153 static void session_destroy(struct spandsp_pvt *p);
 154 static int t38_tx_packet_handler(t38_core_state_t *t38_core_state, void *data, const uint8_t *buf, int len, int count);
 155 static void t30_phase_e_handler(t30_state_t *t30_state, void *data, int completion_code);
 156 static void spandsp_log(int level, const char *msg);
 157 static int update_stats(struct spandsp_pvt *p, int completion_code);
 158
 159 static void set_logging(logging_state_t *state, struct ast_fax_session_details *details);
 160 static void set_local_info(t30_state_t *t30_state, struct ast_fax_session_details *details);
 161 static void set_file(t30_state_t *t30_state, struct ast_fax_session_details *details);
 162 static void set_ecm(t30_state_t *t30_state, struct ast_fax_session_details *details);
 163
 164 static void session_destroy(struct spandsp_pvt *p)
 165 {
 166         struct ast_frame *f;
 167
 168         t30_terminate(p->t30_state);
 169         p->isdone = 1;
 170
 171         ast_timer_close(p->timer);
 172
 173         fax_release(&p->fax_state);
 174         t38_terminal_release(&p->t38_state);
 175
 176         while ((f = AST_LIST_REMOVE_HEAD(&p->read_frames, frame_list))) {
 177                 ast_frfree(f);
 178         }
 179 }
 180
 181 /*! \brief
 182  *
 183  */
 184 static int t38_tx_packet_handler(t38_core_state_t *t38_core_state, void *data, const uint8_t *buf, int len, int count)
 185 {
 186         int res = -1;
 187         struct ast_fax_session *s = data;
 188         struct spandsp_pvt *p = s->tech_pvt;
 189         struct ast_frame fax_frame = {
 190                 .frametype = AST_FRAME_MODEM,
 191                 .subclass.integer = AST_MODEM_T38,
 192                 .src = "res_fax_spandsp_t38",
 193         };
 194
 195         struct ast_frame *f = &fax_frame;
 196
 197
 198         /* TODO: Asterisk does not provide means of resending the same packet multiple
 199           times so count is ignored at the moment */
 200
 201         AST_FRAME_SET_BUFFER(f, buf, 0, len);
 202
 203         if (!(f = ast_frisolate(f))) {
 204                 return res;
 205         }
 206
 207         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 208                 ast_set_flag(f, AST_FAX_FRFLAG_GATEWAY);
 209                 if (p->ast_t38_state == T38_STATE_NEGOTIATED) {
 210                         res = ast_write(s->chan, f);
 211                 } else {
 212                         res = ast_queue_frame(s->chan, f);
 213                 }
 214                 ast_frfree(f);
 215         } else {
 216                 /* no need to lock, this all runs in the same thread */
 217                 AST_LIST_INSERT_TAIL(&p->read_frames, f, frame_list);
 218         }
 219
 220         return res;
 221 }
 222
 223 static int update_stats(struct spandsp_pvt *p, int completion_code)
 224 {
 225         switch (completion_code) {
 226         case T30_ERR_OK:
 227                 ast_atomic_fetchadd_int(&p->stats->success, 1);
 228                 break;
 229
 230         /* Link problems */
 231         case T30_ERR_CEDTONE:            /*! The CED tone exceeded 5s */
 232         case T30_ERR_T0_EXPIRED:         /*! Timed out waiting for initial communication */
 233         case T30_ERR_T1_EXPIRED:         /*! Timed out waiting for the first message */
 234         case T30_ERR_T3_EXPIRED:         /*! Timed out waiting for procedural interrupt */
 235         case T30_ERR_HDLC_CARRIER:       /*! The HDLC carrier did not stop in a timely manner */
 236         case T30_ERR_CANNOT_TRAIN:       /*! Failed to train with any of the compatible modems */
 237                 ast_atomic_fetchadd_int(&p->stats->failed_to_train, 1);
 238                 break;
 239
 240         case T30_ERR_OPER_INT_FAIL:      /*! Operator intervention failed */
 241         case T30_ERR_INCOMPATIBLE:       /*! Far end is not compatible */
 242         case T30_ERR_RX_INCAPABLE:       /*! Far end is not able to receive */
 243         case T30_ERR_TX_INCAPABLE:       /*! Far end is not able to transmit */
 244         case T30_ERR_NORESSUPPORT:       /*! Far end cannot receive at the resolution of the image */
 245         case T30_ERR_NOSIZESUPPORT:      /*! Far end cannot receive at the size of image */
 246                 ast_atomic_fetchadd_int(&p->stats->neg_failed, 1);
 247                 break;
 248
 249         case T30_ERR_UNEXPECTED:         /*! Unexpected message received */
 250                 ast_atomic_fetchadd_int(&p->stats->protocol_error, 1);
 251                 break;
 252
 253         /* Phase E status values returned to a transmitter */
 254         case T30_ERR_TX_BADDCS:          /*! Received bad response to DCS or training */
 255         case T30_ERR_TX_BADPG:           /*! Received a DCN from remote after sending a page */
 256         case T30_ERR_TX_ECMPHD:          /*! Invalid ECM response received from receiver */
 257         case T30_ERR_TX_GOTDCN:          /*! Received a DCN while waiting for a DIS */
 258         case T30_ERR_TX_INVALRSP:        /*! Invalid response after sending a page */
 259         case T30_ERR_TX_NODIS:           /*! Received other than DIS while waiting for DIS */
 260         case T30_ERR_TX_PHBDEAD:         /*! Received no response to DCS, training or TCF */
 261         case T30_ERR_TX_PHDDEAD:         /*! No response after sending a page */
 262         case T30_ERR_TX_T5EXP:           /*! Timed out waiting for receiver ready (ECM mode) */
 263                 ast_atomic_fetchadd_int(&p->stats->tx_protocol_error, 1);
 264                 break;
 265
 266         /* Phase E status values returned to a receiver */
 267         case T30_ERR_RX_ECMPHD:          /*! Invalid ECM response received from transmitter */
 268         case T30_ERR_RX_GOTDCS:          /*! DCS received while waiting for DTC */
 269         case T30_ERR_RX_INVALCMD:        /*! Unexpected command after page received */
 270         case T30_ERR_RX_NOCARRIER:       /*! Carrier lost during fax receive */
 271         case T30_ERR_RX_NOEOL:           /*! Timed out while waiting for EOL (end Of line) */
 272                 ast_atomic_fetchadd_int(&p->stats->rx_protocol_error, 1);
 273                 break;
 274         case T30_ERR_RX_NOFAX:           /*! Timed out while waiting for first line */
 275                 ast_atomic_fetchadd_int(&p->stats->nofax, 1);
 276                 break;
 277         case T30_ERR_RX_T2EXPDCN:        /*! Timer T2 expired while waiting for DCN */
 278         case T30_ERR_RX_T2EXPD:          /*! Timer T2 expired while waiting for phase D */
 279         case T30_ERR_RX_T2EXPFAX:        /*! Timer T2 expired while waiting for fax page */
 280         case T30_ERR_RX_T2EXPMPS:        /*! Timer T2 expired while waiting for next fax page */
 281         case T30_ERR_RX_T2EXPRR:         /*! Timer T2 expired while waiting for RR command */
 282         case T30_ERR_RX_T2EXP:           /*! Timer T2 expired while waiting for NSS, DCS or MCF */
 283         case T30_ERR_RX_DCNWHY:          /*! Unexpected DCN while waiting for DCS or DIS */
 284         case T30_ERR_RX_DCNDATA:         /*! Unexpected DCN while waiting for image data */
 285         case T30_ERR_RX_DCNFAX:          /*! Unexpected DCN while waiting for EOM, EOP or MPS */
 286         case T30_ERR_RX_DCNPHD:          /*! Unexpected DCN after EOM or MPS sequence */
 287         case T30_ERR_RX_DCNRRD:          /*! Unexpected DCN after RR/RNR sequence */
 288         case T30_ERR_RX_DCNNORTN:        /*! Unexpected DCN after requested retransmission */
 289                 ast_atomic_fetchadd_int(&p->stats->rx_protocol_error, 1);
 290                 break;
 291
 292         /* TIFF file problems */
 293         case T30_ERR_FILEERROR:          /*! TIFF/F file cannot be opened */
 294         case T30_ERR_NOPAGE:             /*! TIFF/F page not found */
 295         case T30_ERR_BADTIFF:            /*! TIFF/F format is not compatible */
 296         case T30_ERR_BADPAGE:            /*! TIFF/F page number tag missing */
 297         case T30_ERR_BADTAG:             /*! Incorrect values for TIFF/F tags */
 298         case T30_ERR_BADTIFFHDR:         /*! Bad TIFF/F header - incorrect values in fields */
 299                 ast_atomic_fetchadd_int(&p->stats->file_error, 1);
 300                 break;
 301         case T30_ERR_NOMEM:              /*! Cannot allocate memory for more pages */
 302                 ast_atomic_fetchadd_int(&p->stats->mem_error, 1);
 303                 break;
 304
 305         /* General problems */
 306         case T30_ERR_RETRYDCN:           /*! Disconnected after permitted retries */
 307                 ast_atomic_fetchadd_int(&p->stats->retries_exceeded, 1);
 308                 break;
 309         case T30_ERR_CALLDROPPED:        /*! The call dropped prematurely */
 310                 ast_atomic_fetchadd_int(&p->stats->call_dropped, 1);
 311                 break;
 312
 313         /* Feature negotiation issues */
 314         case T30_ERR_NOPOLL:             /*! Poll not accepted */
 315         case T30_ERR_IDENT_UNACCEPTABLE: /*! Far end's ident is not acceptable */
 316         case T30_ERR_SUB_UNACCEPTABLE:   /*! Far end's sub-address is not acceptable */
 317         case T30_ERR_SEP_UNACCEPTABLE:   /*! Far end's selective polling address is not acceptable */
 318         case T30_ERR_PSA_UNACCEPTABLE:   /*! Far end's polled sub-address is not acceptable */
 319         case T30_ERR_SID_UNACCEPTABLE:   /*! Far end's sender identification is not acceptable */
 320         case T30_ERR_PWD_UNACCEPTABLE:   /*! Far end's password is not acceptable */
 321         case T30_ERR_TSA_UNACCEPTABLE:   /*! Far end's transmitting subscriber internet address is not acceptable */
 322         case T30_ERR_IRA_UNACCEPTABLE:   /*! Far end's internet routing address is not acceptable */
 323         case T30_ERR_CIA_UNACCEPTABLE:   /*! Far end's calling subscriber internet address is not acceptable */
 324         case T30_ERR_ISP_UNACCEPTABLE:   /*! Far end's internet selective polling address is not acceptable */
 325         case T30_ERR_CSA_UNACCEPTABLE:   /*! Far end's called subscriber internet address is not acceptable */
 326                 ast_atomic_fetchadd_int(&p->stats->neg_failed, 1);
 327                 break;
 328         default:
 329                 ast_atomic_fetchadd_int(&p->stats->unknown_error, 1);
 330                 ast_log(LOG_WARNING, "unknown FAX session result '%d' (%s)\n", completion_code, t30_completion_code_to_str(completion_code));
 331                 return -1;
 332         }
 333         return 0;
 334 }
 335
 336 /*! \brief Phase E handler callback.
 337  * \param t30_state the span t30 state
 338  * \param data this will be the ast_fax_session
 339  * \param completion_code the result of the fax session
 340  *
 341  * This function pulls stats from the spandsp stack and stores them for res_fax
 342  * to use later.
 343  */
 344 static void t30_phase_e_handler(t30_state_t *t30_state, void *data, int completion_code)
 345 {
 346         struct ast_fax_session *s = data;
 347         struct spandsp_pvt *p = s->tech_pvt;
 348         char headerinfo[T30_MAX_PAGE_HEADER_INFO + 1];
 349         const char *c;
 350         t30_stats_t stats;
 351
 352         ast_debug(5, "FAX session '%d' entering phase E\n", s->id);
 353
 354         p->isdone = 1;
 355
 356         update_stats(p, completion_code);
 357
 358         t30_get_transfer_statistics(t30_state, &stats);
 359
 360         if (completion_code == T30_ERR_OK) {
 361                 ast_string_field_set(s->details, result, "SUCCESS");
 362         } else {
 363                 ast_string_field_set(s->details, result, "FAILED");
 364                 ast_string_field_set(s->details, error, t30_completion_code_to_str(completion_code));
 365         }
 366
 367         ast_string_field_set(s->details, resultstr, t30_completion_code_to_str(completion_code));
 368
 369         ast_debug(5, "FAX session '%d' completed with result: %s (%s)\n", s->id, s->details->result, s->details->resultstr);
 370
 371         if ((c = t30_get_tx_ident(t30_state))) {
 372                 ast_string_field_set(s->details, localstationid, c);
 373         }
 374
 375         if ((c = t30_get_rx_ident(t30_state))) {
 376                 ast_string_field_set(s->details, remotestationid, c);
 377         }
 378
 379 #if SPANDSP_RELEASE_DATE >= 20090220
 380         s->details->pages_transferred = (s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_rx : stats.pages_tx;
 381 #else
 382         s->details->pages_transferred = stats.pages_transferred;
 383 #endif
 384
 385         ast_string_field_build(s->details, transfer_rate, "%d", stats.bit_rate);
 386
 387         ast_string_field_build(s->details, resolution, "%dx%d", stats.x_resolution, stats.y_resolution);
 388
 389         t30_get_tx_page_header_info(t30_state, headerinfo);
 390         ast_string_field_set(s->details, headerinfo, headerinfo);
 391 }
 392
 393 /*! \brief Send spandsp log messages to asterisk.
 394  * \param level the spandsp logging level
 395  * \param msg the log message
 396  *
 397  * \note This function is a callback function called by spandsp.
 398  */
 399 static void spandsp_log(int level, const char *msg)
 400 {
 401         if (level == SPAN_LOG_ERROR) {
 402                 ast_log(LOG_ERROR, "%s", msg);
 403         } else if (level == SPAN_LOG_WARNING) {
 404                 ast_log(LOG_WARNING, "%s", msg);
 405         } else {
 406                 ast_fax_log(LOG_DEBUG, msg);
 407         }
 408 }
 409
 410 static void set_logging(logging_state_t *state, struct ast_fax_session_details *details)
 411 {
 412         int level = SPAN_LOG_WARNING;
 413
 414         if (details->option.debug) {
 415                 level = SPAN_LOG_DEBUG_3;
 416         }
 417
 418         span_log_set_message_handler(state, spandsp_log);
 419         span_log_set_level(state, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | level);
 420 }
 421
 422 static void set_local_info(t30_state_t *t30_state, struct ast_fax_session_details *details)
 423 {
 424         if (!ast_strlen_zero(details->localstationid)) {
 425                 t30_set_tx_ident(t30_state, details->localstationid);
 426         }
 427
 428         if (!ast_strlen_zero(details->headerinfo)) {
 429                 t30_set_tx_page_header_info(t30_state, details->headerinfo);
 430         }
 431 }
 432
 433 static void set_file(t30_state_t *t30_state, struct ast_fax_session_details *details)
 434 {
 435         if (details->caps & AST_FAX_TECH_RECEIVE) {
 436                 t30_set_rx_file(t30_state, AST_LIST_FIRST(&details->documents)->filename, -1);
 437         } else {
 438                 /* if not AST_FAX_TECH_RECEIVE, assume AST_FAX_TECH_SEND, this
 439                  * should be safe because we ensure either RECEIVE or SEND is
 440                  * indicated in spandsp_fax_new() */
 441                 t30_set_tx_file(t30_state, AST_LIST_FIRST(&details->documents)->filename, -1, -1);
 442         }
 443 }
 444
 445 static void set_ecm(t30_state_t *t30_state, struct ast_fax_session_details *details)
 446 {
 447         t30_set_ecm_capability(t30_state, details->option.ecm);
 448         t30_set_supported_compressions(t30_state, T30_SUPPORT_T4_1D_COMPRESSION | T30_SUPPORT_T4_2D_COMPRESSION | T30_SUPPORT_T6_COMPRESSION);
 449 }
 450
 451 /*! \brief create an instance of the spandsp tech_pvt for a fax session */
 452 static void *spandsp_fax_new(struct ast_fax_session *s, struct ast_fax_tech_token *token)
 453 {
 454         struct spandsp_pvt *p;
 455         int caller_mode;
 456
 457         if ((!(p = ast_calloc(1, sizeof(*p))))) {
 458                 ast_log(LOG_ERROR, "Cannot initialize the spandsp private FAX technology structure.\n");
 459                 goto e_return;
 460         }
 461
 462         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 463                 s->state = AST_FAX_STATE_INITIALIZED;
 464                 return p;
 465         }
 466
 467         AST_LIST_HEAD_INIT(&p->read_frames);
 468
 469         if (s->details->caps & AST_FAX_TECH_RECEIVE) {
 470                 caller_mode = 0;
 471         } else if (s->details->caps & AST_FAX_TECH_SEND) {
 472                 caller_mode = 1;
 473         } else {
 474                 ast_log(LOG_ERROR, "Are we sending or receiving? The FAX requirements (capabilities: 0x%X) were not properly set.\n", s->details->caps);
 475                 goto e_free;
 476         }
 477
 478         if (!(p->timer = ast_timer_open())) {
 479                 ast_log(LOG_ERROR, "Channel '%s' FAX session '%d' failed to create timing source.\n", s->channame, s->id);
 480                 goto e_free;
 481         }
 482
 483         s->fd = ast_timer_fd(p->timer);
 484
 485         p->stats = &spandsp_global_stats.g711;
 486
 487         if (s->details->caps & AST_FAX_TECH_T38) {
 488                 if ((s->details->caps & AST_FAX_TECH_AUDIO) == 0) {
 489                         /* audio mode was not requested, start in T.38 mode */
 490                         p->ist38 = 1;
 491                         p->stats = &spandsp_global_stats.t38;
 492                 }
 493
 494                 /* init t38 stuff */
 495                 t38_terminal_init(&p->t38_state, caller_mode, t38_tx_packet_handler, s);
 496                 set_logging(&p->t38_state.logging, s->details);
 497         }
 498
 499         if (s->details->caps & AST_FAX_TECH_AUDIO) {
 500                 /* init audio stuff */
 501                 fax_init(&p->fax_state, caller_mode);
 502                 set_logging(&p->fax_state.logging, s->details);
 503         }
 504
 505         s->state = AST_FAX_STATE_INITIALIZED;
 506         return p;
 507
 508 e_free:
 509         ast_free(p);
 510 e_return:
 511         return NULL;
 512 }
 513
 514 /*! \brief Destroy a spandsp fax session.
 515  */
 516 static void spandsp_fax_destroy(struct ast_fax_session *s)
 517 {
 518         struct spandsp_pvt *p = s->tech_pvt;
 519
 520         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 521                 spandsp_fax_gateway_cleanup(s);
 522         } else {
 523                 session_destroy(p);
 524         }
 525
 526         ast_free(p);
 527         s->tech_pvt = NULL;
 528         s->fd = -1;
 529 }
 530
 531 /*! \brief Read a frame from the spandsp fax stack.
 532  */
 533 static struct ast_frame *spandsp_fax_read(struct ast_fax_session *s)
 534 {
 535         struct spandsp_pvt *p = s->tech_pvt;
 536         uint8_t buffer[AST_FRIENDLY_OFFSET + SPANDSP_FAX_SAMPLES * sizeof(uint16_t)];
 537         int16_t *buf = (int16_t *) (buffer + AST_FRIENDLY_OFFSET);
 538         int samples;
 539
 540         struct ast_frame fax_frame = {
 541                 .frametype = AST_FRAME_VOICE,
 542                 .src = "res_fax_spandsp_g711",
 543         };
 544         struct ast_frame *f = &fax_frame;
 545         ast_format_set(&fax_frame.subclass.format, AST_FORMAT_SLINEAR, 0);
 546
 547         ast_timer_ack(p->timer, 1);
 548
 549         /* XXX do we need to lock here? */
 550         if (p->isdone) {
 551                 s->state = AST_FAX_STATE_COMPLETE;
 552                 ast_debug(5, "FAX session '%d' is complete.\n", s->id);
 553                 return NULL;
 554         }
 555
 556         if (p->ist38) {
 557                 t38_terminal_send_timeout(&p->t38_state, SPANDSP_FAX_SAMPLES);
 558                 if ((f = AST_LIST_REMOVE_HEAD(&p->read_frames, frame_list))) {
 559                         return f;
 560                 }
 561         } else {
 562                 if ((samples = fax_tx(&p->fax_state, buf, SPANDSP_FAX_SAMPLES)) > 0) {
 563                         f->samples = samples;
 564                         AST_FRAME_SET_BUFFER(f, buffer, AST_FRIENDLY_OFFSET, samples * sizeof(int16_t));
 565                         return ast_frisolate(f);
 566                 }
 567         }
 568
 569         return &ast_null_frame;
 570 }
 571
 572 /*! \brief Write a frame to the spandsp fax stack.
 573  * \param s a fax session
 574  * \param f the frame to write
 575  *
 576  * \note res_fax does not currently use the return value of this function.
 577  * Also the fax_rx() function never fails.
 578  *
 579  * \retval 0 success
 580  * \retval -1 failure
 581  */
 582 static int spandsp_fax_write(struct ast_fax_session *s, const struct ast_frame *f)
 583 {
 584         struct spandsp_pvt *p = s->tech_pvt;
 585
 586         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 587                 return spandsp_fax_gateway_process(s, f);
 588         }
 589
 590         /* XXX do we need to lock here? */
 591         if (s->state == AST_FAX_STATE_COMPLETE) {
 592                 ast_log(LOG_WARNING, "FAX session '%d' is in the '%s' state.\n", s->id, ast_fax_state_to_str(s->state));
 593                 return -1;
 594         }
 595
 596         if (p->ist38) {
 597                 return t38_core_rx_ifp_packet(p->t38_core_state, f->data.ptr, f->datalen, f->seqno);
 598         } else {
 599                 return fax_rx(&p->fax_state, f->data.ptr, f->samples);
 600         }
 601 }
 602
 603 /*! \brief generate T.30 packets sent to the T.30 leg of gateway
 604  * \param chan T.30 channel
 605  * \param data fax session structure
 606  * \param len not used
 607  * \param samples no of samples generated
 608  * \return -1 on failure or 0 on sucess*/
 609 static int spandsp_fax_gw_t30_gen(struct ast_channel *chan, void *data, int len, int samples)
 610 {
 611         int res = -1;
 612         struct ast_fax_session *s = data;
 613         struct spandsp_pvt *p = s->tech_pvt;
 614         uint8_t buffer[AST_FRIENDLY_OFFSET + samples * sizeof(uint16_t)];
 615         struct ast_frame *f;
 616         struct ast_frame t30_frame = {
 617                 .frametype = AST_FRAME_VOICE,
 618                 .src = "res_fax_spandsp_g711",
 619                 .samples = samples,
 620                 .flags = AST_FAX_FRFLAG_GATEWAY,
 621         };
 622
 623         AST_FRAME_SET_BUFFER(&t30_frame, buffer, AST_FRIENDLY_OFFSET, t30_frame.samples * sizeof(int16_t));
 624
 625         ast_format_set(&t30_frame.subclass.format, AST_FORMAT_SLINEAR, 0);
 626         if (!(f = ast_frisolate(&t30_frame))) {
 627                 return p->isdone ? -1 : res;
 628         }
 629
 630         /* generate a T.30 packet */
 631         if ((f->samples = t38_gateway_tx(&p->t38_gw_state, f->data.ptr, f->samples))) {
 632                 f->datalen = f->samples * sizeof(int16_t);
 633                 res = ast_write(chan, f);
 634         }
 635         ast_frfree(f);
 636         return p->isdone ? -1 : res;
 637 }
 638
 639 /*! \brief simple routine to allocate data to generator
 640  * \param chan channel
 641  * \param params generator data
 642  * \return data to use in generator call*/
 643 static void *spandsp_fax_gw_gen_alloc(struct ast_channel *chan, void *params) {
 644         ao2_ref(params, +1);
 645         return params;
 646 }
 647
 648 static void spandsp_fax_gw_gen_release(struct ast_channel *chan, void *data) {
 649         ao2_ref(data, -1);
 650 }
 651
 652 /*! \brief activate a spandsp gateway based on the information in the given fax session
 653  * \param s fax session
 654  * \return -1 on error 0 on sucess*/
 655 static int spandsp_fax_gateway_start(struct ast_fax_session *s) {
 656         struct spandsp_pvt *p = s->tech_pvt;
 657         struct ast_fax_t38_parameters *t38_param;
 658         int i, modems = 0;
 659         struct ast_channel *peer;
 660         static struct ast_generator t30_gen = {
 661                 alloc: spandsp_fax_gw_gen_alloc,
 662                 release: spandsp_fax_gw_gen_release,
 663                 generate: spandsp_fax_gw_t30_gen,
 664         };
 665
 666 #if SPANDSP_RELEASE_DATE >= 20081012
 667         /* for spandsp shaphots 0.0.6 and higher */
 668         p->t38_core_state=&p->t38_gw_state.t38x.t38;
 669 #else
 670         /* for spandsp release 0.0.5 */
 671         p->t38_core_state=&p->t38_gw_state.t38;
 672 #endif
 673
 674         if (!t38_gateway_init(&p->t38_gw_state, t38_tx_packet_handler, s)) {
 675                 return -1;
 676         }
 677
 678         p->ist38 = 1;
 679         p->ast_t38_state = ast_channel_get_t38_state(s->chan);
 680         if (!(peer = ast_bridged_channel(s->chan))) {
 681                 ast_channel_unlock(s->chan);
 682                 return -1;
 683         }
 684         ast_activate_generator(p->ast_t38_state == T38_STATE_NEGOTIATED ? peer : s->chan, &t30_gen , s);
 685
 686         set_logging(&p->t38_gw_state.logging, s->details);
 687         set_logging(&p->t38_core_state->logging, s->details);
 688
 689         t38_param = (p->ast_t38_state == T38_STATE_NEGOTIATED) ? &s->details->our_t38_parameters : &s->details->their_t38_parameters;
 690         t38_set_t38_version(p->t38_core_state, t38_param->version);
 691         t38_gateway_set_ecm_capability(&p->t38_gw_state, s->details->option.ecm);
 692         t38_set_max_datagram_size(p->t38_core_state, t38_param->max_ifp);
 693         t38_set_fill_bit_removal(p->t38_core_state, t38_param->fill_bit_removal);
 694         t38_set_mmr_transcoding(p->t38_core_state, t38_param->transcoding_mmr);
 695         t38_set_jbig_transcoding(p->t38_core_state, t38_param->transcoding_jbig);
 696         t38_set_data_rate_management_method(p->t38_core_state,
 697                         (t38_param->rate_management == AST_T38_RATE_MANAGEMENT_TRANSFERRED_TCF)? 1 : 2);
 698
 699         t38_gateway_set_transmit_on_idle(&p->t38_gw_state, TRUE);
 700         t38_set_sequence_number_handling(p->t38_core_state, TRUE);
 701
 702         if (AST_FAX_MODEM_V17 & s->details->modems) {
 703                 modems |= T30_SUPPORT_V17;
 704         }
 705         if (AST_FAX_MODEM_V27 & s->details->modems) {
 706                 modems |= T30_SUPPORT_V27TER;
 707         }
 708         if (AST_FAX_MODEM_V29 & s->details->modems) {
 709                 modems |= T30_SUPPORT_V29;
 710         }
 711         if (AST_FAX_MODEM_V34 & s->details->modems) {
 712 #if defined(T30_SUPPORT_V34)
 713                 modems |= T30_SUPPORT_V34;
 714 #elif defined(T30_SUPPORT_V34HDX)
 715                 modems |= T30_SUPPORT_V34HDX;
 716 #else
 717                 ast_log(LOG_WARNING, "v34 not supported in this version of spandsp\n");
 718 #endif
 719         }
 720
 721         t38_gateway_set_supported_modems(&p->t38_gw_state, modems);
 722
 723         /* engage udptl nat on other side of T38 line
 724          * (Asterisk changes media ports thus we send a few packets to reinitialize
 725          * pinholes in NATs and FWs
 726          */
 727         for (i=0; i < SPANDSP_ENGAGE_UDPTL_NAT_RETRY; i++) {
 728 #if SPANDSP_RELEASE_DATE >= 20091228
 729                 t38_core_send_indicator(&p->t38_gw_state.t38x.t38, T38_IND_NO_SIGNAL);
 730 #elif SPANDSP_RELEASE_DATE >= 20081012
 731                 t38_core_send_indicator(&p->t38_gw_state.t38x.t38, T38_IND_NO_SIGNAL, p->t38_gw_state.t38x.t38.indicator_tx_count);
 732 #else
 733                 t38_core_send_indicator(&p->t38_gw_state.t38, T38_IND_NO_SIGNAL, p->t38_gw_state.t38.indicator_tx_count);
 734 #endif
 735         }
 736
 737         s->state = AST_FAX_STATE_ACTIVE;
 738
 739         return 0;
 740 }
 741
 742 /*! \brief process a frame from the bridge
 743  * \param s fax session
 744  * \param f frame to process
 745  * \return 1 on sucess 0 on incorect packet*/
 746 static int spandsp_fax_gateway_process(struct ast_fax_session *s, const struct ast_frame *f)
 747 {
 748         struct spandsp_pvt *p = s->tech_pvt;
 749
 750         /*invalid frame*/
 751         if (!f->data.ptr || !f->datalen) {
 752                 return -1;
 753         }
 754
 755         /* Process a IFP packet */
 756         if ((f->frametype == AST_FRAME_MODEM) && (f->subclass.integer == AST_MODEM_T38)) {
 757                 return t38_core_rx_ifp_packet(p->t38_core_state, f->data.ptr, f->datalen, f->seqno);
 758         } else if ((f->frametype == AST_FRAME_VOICE) && (f->subclass.format.id == AST_FORMAT_SLINEAR)) {
 759                 return t38_gateway_rx(&p->t38_gw_state, f->data.ptr, f->samples);
 760         }
 761
 762         return -1;
 763 }
 764
 765 /*! \brief gather data and clean up after gateway ends
 766  * \param s fax session*/
 767 static void spandsp_fax_gateway_cleanup(struct ast_fax_session *s)
 768 {
 769         struct spandsp_pvt *p = s->tech_pvt;
 770         t38_stats_t t38_stats;
 771
 772         t38_gateway_get_transfer_statistics(&p->t38_gw_state, &t38_stats);
 773
 774         s->details->option.ecm = t38_stats.error_correcting_mode ? AST_FAX_OPTFLAG_TRUE : AST_FAX_OPTFLAG_FALSE;
 775         s->details->pages_transferred = t38_stats.pages_transferred;
 776         ast_string_field_build(s->details, transfer_rate, "%d", t38_stats.bit_rate);
 777 }
 778
 779 /*! \brief */
 780 static int spandsp_fax_start(struct ast_fax_session *s)
 781 {
 782         struct spandsp_pvt *p = s->tech_pvt;
 783
 784         s->state = AST_FAX_STATE_OPEN;
 785
 786         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 787                 return spandsp_fax_gateway_start(s);
 788         }
 789
 790         if (p->ist38) {
 791 #if SPANDSP_RELEASE_DATE >= 20080725
 792                 /* for spandsp shaphots 0.0.6 and higher */
 793                 p->t30_state = &p->t38_state.t30;
 794                 p->t38_core_state = &p->t38_state.t38_fe.t38;
 795 #else
 796                 /* for spandsp releases 0.0.5 */
 797                 p->t30_state = &p->t38_state.t30_state;
 798                 p->t38_core_state = &p->t38_state.t38;
 799 #endif
 800         } else {
 801 #if SPANDSP_RELEASE_DATE >= 20080725
 802                 /* for spandsp shaphots 0.0.6 and higher */
 803                 p->t30_state = &p->fax_state.t30;
 804 #else
 805                 /* for spandsp release 0.0.5 */
 806                 p->t30_state = &p->fax_state.t30_state;
 807 #endif
 808         }
 809
 810         set_logging(&p->t30_state->logging, s->details);
 811
 812         /* set some parameters */
 813         set_local_info(p->t30_state, s->details);
 814         set_file(p->t30_state, s->details);
 815         set_ecm(p->t30_state, s->details);
 816
 817         /* perhaps set_transmit_on_idle() should be called */
 818
 819         t30_set_phase_e_handler(p->t30_state, t30_phase_e_handler, s);
 820
 821         /* set T.38 parameters */
 822         if (p->ist38) {
 823                 set_logging(&p->t38_core_state->logging, s->details);
 824
 825                 t38_set_max_datagram_size(p->t38_core_state, s->details->their_t38_parameters.max_ifp);
 826
 827                 if (s->details->their_t38_parameters.fill_bit_removal) {
 828                         t38_set_fill_bit_removal(p->t38_core_state, TRUE);
 829                 }
 830
 831                 if (s->details->their_t38_parameters.transcoding_mmr) {
 832                         t38_set_mmr_transcoding(p->t38_core_state, TRUE);
 833                 }
 834
 835                 if (s->details->their_t38_parameters.transcoding_jbig) {
 836                         t38_set_jbig_transcoding(p->t38_core_state, TRUE);
 837                 }
 838         } else {
 839                 /* have the fax stack generate silence if it has no data to send */
 840                 fax_set_transmit_on_idle(&p->fax_state, 1);
 841         }
 842
 843
 844         /* start the timer */
 845         if (ast_timer_set_rate(p->timer, SPANDSP_FAX_TIMER_RATE)) {
 846                 ast_log(LOG_ERROR, "FAX session '%d' error setting rate on timing source.\n", s->id);
 847                 return -1;
 848         }
 849
 850         s->state = AST_FAX_STATE_ACTIVE;
 851
 852         return 0;
 853 }
 854
 855 /*! \brief */
 856 static int spandsp_fax_cancel(struct ast_fax_session *s)
 857 {
 858         struct spandsp_pvt *p = s->tech_pvt;
 859
 860         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 861                 p->isdone = 1;
 862                 return 0;
 863         }
 864
 865         t30_terminate(p->t30_state);
 866         p->isdone = 1;
 867         return 0;
 868 }
 869
 870 /*! \brief */
 871 static int spandsp_fax_switch_to_t38(struct ast_fax_session *s)
 872 {
 873         struct spandsp_pvt *p = s->tech_pvt;
 874
 875         /* prevent the phase E handler from running, this is not a real termination */
 876         t30_set_phase_e_handler(p->t30_state, NULL, NULL);
 877
 878         t30_terminate(p->t30_state);
 879
 880         s->details->option.switch_to_t38 = 1;
 881         ast_atomic_fetchadd_int(&p->stats->switched, 1);
 882
 883         p->ist38 = 1;
 884         p->stats = &spandsp_global_stats.t38;
 885         spandsp_fax_start(s);
 886
 887         return 0;
 888 }
 889
 890 /*! \brief */
 891 static char *spandsp_fax_cli_show_capabilities(int fd)
 892 {
 893         ast_cli(fd, "SEND RECEIVE T.38 G.711 GATEWAY\n\n");
 894         return  CLI_SUCCESS;
 895 }
 896
 897 /*! \brief */
 898 static char *spandsp_fax_cli_show_session(struct ast_fax_session *s, int fd)
 899 {
 900         struct spandsp_pvt *p = s->tech_pvt;
 901
 902         ao2_lock(s);
 903         if (s->details->caps & AST_FAX_TECH_GATEWAY) {
 904                 ast_cli(fd, "%-22s : %d\n", "session", s->id);
 905                 ast_cli(fd, "%-22s : %s\n", "operation", "Gateway");
 906                 ast_cli(fd, "%-22s : %s\n", "state", ast_fax_state_to_str(s->state));
 907                 if (s->state != AST_FAX_STATE_UNINITIALIZED) {
 908                         t38_stats_t stats;
 909                         t38_gateway_get_transfer_statistics(&p->t38_gw_state, &stats);
 910                         ast_cli(fd, "%-22s : %s\n", "ECM Mode", stats.error_correcting_mode ? "Yes" : "No");
 911                         ast_cli(fd, "%-22s : %d\n", "Data Rate", stats.bit_rate);
 912                         ast_cli(fd, "%-22s : %d\n", "Page Number", stats.pages_transferred + 1);
 913                 }
 914         } else {
 915                 ast_cli(fd, "%-22s : %d\n", "session", s->id);
 916                 ast_cli(fd, "%-22s : %s\n", "operation", (s->details->caps & AST_FAX_TECH_RECEIVE) ? "Receive" : "Transmit");
 917                 ast_cli(fd, "%-22s : %s\n", "state", ast_fax_state_to_str(s->state));
 918                 if (s->state != AST_FAX_STATE_UNINITIALIZED) {
 919                         t30_stats_t stats;
 920                         t30_get_transfer_statistics(p->t30_state, &stats);
 921                         ast_cli(fd, "%-22s : %s\n", "Last Status", t30_completion_code_to_str(stats.current_status));
 922                         ast_cli(fd, "%-22s : %s\n", "ECM Mode", stats.error_correcting_mode ? "Yes" : "No");
 923                         ast_cli(fd, "%-22s : %d\n", "Data Rate", stats.bit_rate);
 924                         ast_cli(fd, "%-22s : %dx%d\n", "Image Resolution", stats.x_resolution, stats.y_resolution);
 925 #if SPANDSP_RELEASE_DATE >= 20090220
 926                         ast_cli(fd, "%-22s : %d\n", "Page Number", ((s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_rx : stats.pages_tx) + 1);
 927 #else
 928                         ast_cli(fd, "%-22s : %d\n", "Page Number", stats.pages_transferred + 1);
 929 #endif
 930                         ast_cli(fd, "%-22s : %s\n", "File Name", s->details->caps & AST_FAX_TECH_RECEIVE ? p->t30_state->rx_file : p->t30_state->tx_file);
 931
 932                         ast_cli(fd, "\nData Statistics:\n");
 933 #if SPANDSP_RELEASE_DATE >= 20090220
 934                         ast_cli(fd, "%-22s : %d\n", "Tx Pages", stats.pages_tx);
 935                         ast_cli(fd, "%-22s : %d\n", "Rx Pages", stats.pages_rx);
 936 #else
 937                         ast_cli(fd, "%-22s : %d\n", "Tx Pages", (s->details->caps & AST_FAX_TECH_SEND) ? stats.pages_transferred : 0);
 938                         ast_cli(fd, "%-22s : %d\n", "Rx Pages", (s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_transferred : 0);
 939 #endif
 940                         ast_cli(fd, "%-22s : %d\n", "Longest Bad Line Run", stats.longest_bad_row_run);
 941                         ast_cli(fd, "%-22s : %d\n", "Total Bad Lines", stats.bad_rows);
 942                 }
 943         }
 944         ao2_unlock(s);
 945         ast_cli(fd, "\n\n");
 946         return CLI_SUCCESS;
 947 }
 948
 949 /*! \brief */
 950 static char *spandsp_fax_cli_show_stats(int fd)
 951 {
 952         ast_mutex_lock(&spandsp_global_stats.lock);
 953         ast_cli(fd, "\n%-20.20s\n", "Spandsp G.711");
 954         ast_cli(fd, "%-20.20s : %d\n", "Success", spandsp_global_stats.g711.success);
 955         ast_cli(fd, "%-20.20s : %d\n", "Switched to T.38", spandsp_global_stats.g711.switched);
 956         ast_cli(fd, "%-20.20s : %d\n", "Call Dropped", spandsp_global_stats.g711.call_dropped);
 957         ast_cli(fd, "%-20.20s : %d\n", "No FAX", spandsp_global_stats.g711.nofax);
 958         ast_cli(fd, "%-20.20s : %d\n", "Negotiation Failed", spandsp_global_stats.g711.neg_failed);
 959         ast_cli(fd, "%-20.20s : %d\n", "Train Failure", spandsp_global_stats.g711.failed_to_train);
 960         ast_cli(fd, "%-20.20s : %d\n", "Retries Exceeded", spandsp_global_stats.g711.retries_exceeded);
 961         ast_cli(fd, "%-20.20s : %d\n", "Protocol Error", spandsp_global_stats.g711.protocol_error);
 962         ast_cli(fd, "%-20.20s : %d\n", "TX Protocol Error", spandsp_global_stats.g711.tx_protocol_error);
 963         ast_cli(fd, "%-20.20s : %d\n", "RX Protocol Error", spandsp_global_stats.g711.rx_protocol_error);
 964         ast_cli(fd, "%-20.20s : %d\n", "File Error", spandsp_global_stats.g711.file_error);
 965         ast_cli(fd, "%-20.20s : %d\n", "Memory Error", spandsp_global_stats.g711.mem_error);
 966         ast_cli(fd, "%-20.20s : %d\n", "Unknown Error", spandsp_global_stats.g711.unknown_error);
 967
 968         ast_cli(fd, "\n%-20.20s\n", "Spandsp T.38");
 969         ast_cli(fd, "%-20.20s : %d\n", "Success", spandsp_global_stats.t38.success);
 970         ast_cli(fd, "%-20.20s : %d\n", "Call Dropped", spandsp_global_stats.t38.call_dropped);
 971         ast_cli(fd, "%-20.20s : %d\n", "No FAX", spandsp_global_stats.t38.nofax);
 972         ast_cli(fd, "%-20.20s : %d\n", "Negotiation Failed", spandsp_global_stats.t38.neg_failed);
 973         ast_cli(fd, "%-20.20s : %d\n", "Train Failure", spandsp_global_stats.t38.failed_to_train);
 974         ast_cli(fd, "%-20.20s : %d\n", "Retries Exceeded", spandsp_global_stats.t38.retries_exceeded);
 975         ast_cli(fd, "%-20.20s : %d\n", "Protocol Error", spandsp_global_stats.t38.protocol_error);
 976         ast_cli(fd, "%-20.20s : %d\n", "TX Protocol Error", spandsp_global_stats.t38.tx_protocol_error);
 977         ast_cli(fd, "%-20.20s : %d\n", "RX Protocol Error", spandsp_global_stats.t38.rx_protocol_error);
 978         ast_cli(fd, "%-20.20s : %d\n", "File Error", spandsp_global_stats.t38.file_error);
 979         ast_cli(fd, "%-20.20s : %d\n", "Memory Error", spandsp_global_stats.t38.mem_error);
 980         ast_cli(fd, "%-20.20s : %d\n", "Unknown Error", spandsp_global_stats.t38.unknown_error);
 981         ast_mutex_unlock(&spandsp_global_stats.lock);
 982
 983         return CLI_SUCCESS;
 984 }
 985
 986 /*! \brief Show res_fax_spandsp settings */
 987 static char *spandsp_fax_cli_show_settings(int fd)
 988 {
 989         /* no settings at the moment */
 990         return CLI_SUCCESS;
 991 }
 992
 993 /*! \brief unload res_fax_spandsp */
 994 static int unload_module(void)
 995 {
 996         ast_fax_tech_unregister(&spandsp_fax_tech);
 997         ast_mutex_destroy(&spandsp_global_stats.lock);
 998         return AST_MODULE_LOAD_SUCCESS;
 999 }
1000
1001 /*! \brief load res_fax_spandsp */
1002 static int load_module(void)
1003 {
1004         ast_mutex_init(&spandsp_global_stats.lock);
1005         spandsp_fax_tech.module = ast_module_info->self;
1006         if (ast_fax_tech_register(&spandsp_fax_tech) < 0) {
1007                 ast_log(LOG_ERROR, "failed to register FAX technology\n");
1008                 return AST_MODULE_LOAD_DECLINE;
1009         }
1010
1011         /* prevent logging to stderr */
1012         span_set_message_handler(NULL);
1013
1014         return AST_MODULE_LOAD_SUCCESS;
1015 }
1016
1017
1018 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Spandsp G.711 and T.38 FAX Technologies",
1019                 .load = load_module,
1020                 .unload = unload_module,
1021                );