Merge res_fax and res_fax_spandsp.

git-svn-id: http://svn.digium.com/svn/asterisk/trunk@250190 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 762 insertions, 0 deletions

diff --git a/res/res_fax_spandsp.c b/res/res_fax_spandsp.c
new file mode 100644
index 000000000..630cccb3b
--- /dev/null
+++ b/res/res_fax_spandsp.c
@@ -0,0 +1,762 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2009-2010, Digium, Inc.
+ *
+ * Matthew Nicholson <mnicholson@digium.com>
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*! \file
+ *
+ * \brief Spandsp T.38 and G.711 FAX Resource
+ *
+ * \author Matthew Nicholson <mnicholson@digium.com>
+ *
+ * This module registers the Spandsp FAX technology with the res_fax module.
+ */
+
+/*** MODULEINFO
+		<depend>spandsp</depend>
+***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
+#include <spandsp.h>
+#include <spandsp/version.h>
+
+#include "asterisk/logger.h"
+#include "asterisk/module.h"
+#include "asterisk/strings.h"
+#include "asterisk/cli.h"
+#include "asterisk/utils.h"
+#include "asterisk/timing.h"
+#include "asterisk/astobj2.h"
+#include "asterisk/res_fax.h"
+
+#define SPANDSP_FAX_SAMPLES 160
+#define SPANDSP_FAX_TIMER_RATE 8000 / SPANDSP_FAX_SAMPLES	/* 50 ticks per second, 20ms, 160 samples per second */
+
+static void *spandsp_fax_new(struct ast_fax_session *s, struct ast_fax_tech_token *token);
+static void spandsp_fax_destroy(struct ast_fax_session *s);
+static struct ast_frame *spandsp_fax_read(struct ast_fax_session *s);
+static int spandsp_fax_write(struct ast_fax_session *s, const struct ast_frame *f);
+static int spandsp_fax_start(struct ast_fax_session *s);
+static int spandsp_fax_cancel(struct ast_fax_session *s);
+static int spandsp_fax_switch_to_t38(struct ast_fax_session *s);
+
+static char *spandsp_fax_cli_show_capabilities(int fd);
+static char *spandsp_fax_cli_show_session(struct ast_fax_session *s, int fd);
+static char *spandsp_fax_cli_show_stats(int fd);
+
+static struct ast_fax_tech spandsp_fax_tech = {
+	.type = "Spandsp",
+	.description = "Spandsp FAX Driver",
+#if SPANDSP_RELEASE_DATE >= 20090220
+	/* spandsp 0.0.6 */
+	.version = SPANDSP_RELEASE_DATETIME_STRING,
+#else
+	/* spandsp 0.0.5
+	 * TODO: maybe we should determine the version better way
+	 */
+	.version = "pre-20090220",
+#endif
+	.caps = AST_FAX_TECH_AUDIO | AST_FAX_TECH_T38 | AST_FAX_TECH_SEND | AST_FAX_TECH_RECEIVE,
+	.new_session = spandsp_fax_new,
+	.destroy_session = spandsp_fax_destroy,
+	.read = spandsp_fax_read,
+	.write = spandsp_fax_write,
+	.start_session = spandsp_fax_start,
+	.cancel_session = spandsp_fax_cancel,
+	.switch_to_t38 = spandsp_fax_switch_to_t38,
+	.cli_show_capabilities = spandsp_fax_cli_show_capabilities,
+	.cli_show_session = spandsp_fax_cli_show_session,
+	.cli_show_stats = spandsp_fax_cli_show_stats,
+};
+
+struct spandsp_fax_stats {
+	int success;
+	int nofax;
+	int neg_failed;
+	int failed_to_train;
+	int rx_protocol_error;
+	int tx_protocol_error;
+	int protocol_error;
+	int retries_exceeded;
+	int file_error;
+	int mem_error;
+	int call_dropped;
+	int unknown_error;
+	int switched;
+};
+
+static struct {
+	ast_mutex_t lock;
+	struct spandsp_fax_stats g711;
+	struct spandsp_fax_stats t38;
+} spandsp_global_stats;
+
+struct spandsp_pvt {
+	unsigned int ist38:1;
+	unsigned int isdone:1;
+	fax_state_t fax_state;
+	t38_terminal_state_t t38_state;
+	t30_state_t *t30_state;
+	t38_core_state_t *t38_core_state;
+
+	struct spandsp_fax_stats *stats;
+
+	struct ast_timer *timer;
+	AST_LIST_HEAD(frame_queue, ast_frame) read_frames;
+};
+
+static void session_destroy(struct spandsp_pvt *p);
+static int t38_tx_packet_handler(t38_core_state_t *t38_core_state, void *data, const uint8_t *buf, int len, int count);
+static void t30_phase_e_handler(t30_state_t *t30_state, void *data, int completion_code);
+static void spandsp_log(int level, const char *msg);
+static int update_stats(struct spandsp_pvt *p, int completion_code);
+
+static void set_logging(logging_state_t *state, struct ast_fax_session_details *details);
+static void set_local_info(t30_state_t *t30_state, struct ast_fax_session_details *details);
+static void set_file(t30_state_t *t30_state, struct ast_fax_session_details *details);
+static void set_ecm(t30_state_t *t30_state, struct ast_fax_session_details *details);
+
+static void session_destroy(struct spandsp_pvt *p)
+{
+	struct ast_frame *f;
+
+	t30_terminate(p->t30_state);
+	p->isdone = 1;
+
+	ast_timer_close(p->timer);
+
+	fax_release(&p->fax_state);
+	t38_terminal_release(&p->t38_state);
+
+	while ((f = AST_LIST_REMOVE_HEAD(&p->read_frames, frame_list))) {
+		ast_frfree(f);
+	}
+}
+
+/*! \brief
+ *
+ */
+static int t38_tx_packet_handler(t38_core_state_t *t38_core_state, void *data, const uint8_t *buf, int len, int count)
+{
+	struct spandsp_pvt *p = data;
+	struct ast_frame fax_frame = {
+		.frametype = AST_FRAME_MODEM,
+		.subclass.integer = AST_MODEM_T38,
+		.src = "res_fax_spandsp_t38",
+	};
+
+	struct ast_frame *f = &fax_frame;
+
+
+	/* TODO: Asterisk does not provide means of resending the same packet multiple
+	  times so count is ignored at the moment */
+
+	AST_FRAME_SET_BUFFER(f, buf, 0, len);
+
+	if (!(f = ast_frisolate(f))) {
+		return -1;
+	}
+
+	/* no need to lock, this all runs in the same thread */
+	AST_LIST_INSERT_TAIL(&p->read_frames, f, frame_list);
+
+	return 0;
+}
+
+static int update_stats(struct spandsp_pvt *p, int completion_code)
+{
+	switch (completion_code) {
+	case T30_ERR_OK:
+		ast_atomic_fetchadd_int(&p->stats->success, 1);
+		break;
+
+	/* Link problems */
+	case T30_ERR_CEDTONE:            /*! The CED tone exceeded 5s */
+	case T30_ERR_T0_EXPIRED:         /*! Timed out waiting for initial communication */
+	case T30_ERR_T1_EXPIRED:         /*! Timed out waiting for the first message */
+	case T30_ERR_T3_EXPIRED:         /*! Timed out waiting for procedural interrupt */
+	case T30_ERR_HDLC_CARRIER:       /*! The HDLC carrier did not stop in a timely manner */
+	case T30_ERR_CANNOT_TRAIN:       /*! Failed to train with any of the compatible modems */
+		ast_atomic_fetchadd_int(&p->stats->failed_to_train, 1);
+		break;
+
+	case T30_ERR_OPER_INT_FAIL:      /*! Operator intervention failed */
+	case T30_ERR_INCOMPATIBLE:       /*! Far end is not compatible */
+	case T30_ERR_RX_INCAPABLE:       /*! Far end is not able to receive */
+	case T30_ERR_TX_INCAPABLE:       /*! Far end is not able to transmit */
+	case T30_ERR_NORESSUPPORT:       /*! Far end cannot receive at the resolution of the image */
+	case T30_ERR_NOSIZESUPPORT:      /*! Far end cannot receive at the size of image */
+		ast_atomic_fetchadd_int(&p->stats->neg_failed, 1);
+		break;
+
+	case T30_ERR_UNEXPECTED:         /*! Unexpected message received */
+		ast_atomic_fetchadd_int(&p->stats->protocol_error, 1);
+		break;
+
+	/* Phase E status values returned to a transmitter */
+	case T30_ERR_TX_BADDCS:          /*! Received bad response to DCS or training */
+	case T30_ERR_TX_BADPG:           /*! Received a DCN from remote after sending a page */
+	case T30_ERR_TX_ECMPHD:          /*! Invalid ECM response received from receiver */
+	case T30_ERR_TX_GOTDCN:          /*! Received a DCN while waiting for a DIS */
+	case T30_ERR_TX_INVALRSP:        /*! Invalid response after sending a page */
+	case T30_ERR_TX_NODIS:           /*! Received other than DIS while waiting for DIS */
+	case T30_ERR_TX_PHBDEAD:         /*! Received no response to DCS, training or TCF */
+	case T30_ERR_TX_PHDDEAD:         /*! No response after sending a page */
+	case T30_ERR_TX_T5EXP:           /*! Timed out waiting for receiver ready (ECM mode) */
+		ast_atomic_fetchadd_int(&p->stats->tx_protocol_error, 1);
+		break;
+
+	/* Phase E status values returned to a receiver */
+	case T30_ERR_RX_ECMPHD:          /*! Invalid ECM response received from transmitter */
+	case T30_ERR_RX_GOTDCS:          /*! DCS received while waiting for DTC */
+	case T30_ERR_RX_INVALCMD:        /*! Unexpected command after page received */
+	case T30_ERR_RX_NOCARRIER:       /*! Carrier lost during fax receive */
+	case T30_ERR_RX_NOEOL:           /*! Timed out while waiting for EOL (end Of line) */
+		ast_atomic_fetchadd_int(&p->stats->rx_protocol_error, 1);
+		break;
+	case T30_ERR_RX_NOFAX:           /*! Timed out while waiting for first line */
+		ast_atomic_fetchadd_int(&p->stats->nofax, 1);
+		break;
+	case T30_ERR_RX_T2EXPDCN:        /*! Timer T2 expired while waiting for DCN */
+	case T30_ERR_RX_T2EXPD:          /*! Timer T2 expired while waiting for phase D */
+	case T30_ERR_RX_T2EXPFAX:        /*! Timer T2 expired while waiting for fax page */
+	case T30_ERR_RX_T2EXPMPS:        /*! Timer T2 expired while waiting for next fax page */
+	case T30_ERR_RX_T2EXPRR:         /*! Timer T2 expired while waiting for RR command */
+	case T30_ERR_RX_T2EXP:           /*! Timer T2 expired while waiting for NSS, DCS or MCF */
+	case T30_ERR_RX_DCNWHY:          /*! Unexpected DCN while waiting for DCS or DIS */
+	case T30_ERR_RX_DCNDATA:         /*! Unexpected DCN while waiting for image data */
+	case T30_ERR_RX_DCNFAX:          /*! Unexpected DCN while waiting for EOM, EOP or MPS */
+	case T30_ERR_RX_DCNPHD:          /*! Unexpected DCN after EOM or MPS sequence */
+	case T30_ERR_RX_DCNRRD:          /*! Unexpected DCN after RR/RNR sequence */
+	case T30_ERR_RX_DCNNORTN:        /*! Unexpected DCN after requested retransmission */
+		ast_atomic_fetchadd_int(&p->stats->rx_protocol_error, 1);
+		break;
+
+	/* TIFF file problems */
+	case T30_ERR_FILEERROR:          /*! TIFF/F file cannot be opened */
+	case T30_ERR_NOPAGE:             /*! TIFF/F page not found */
+	case T30_ERR_BADTIFF:            /*! TIFF/F format is not compatible */
+	case T30_ERR_BADPAGE:            /*! TIFF/F page number tag missing */
+	case T30_ERR_BADTAG:             /*! Incorrect values for TIFF/F tags */
+	case T30_ERR_BADTIFFHDR:         /*! Bad TIFF/F header - incorrect values in fields */
+		ast_atomic_fetchadd_int(&p->stats->file_error, 1);
+		break;
+	case T30_ERR_NOMEM:              /*! Cannot allocate memory for more pages */
+		ast_atomic_fetchadd_int(&p->stats->mem_error, 1);
+		break;
+
+	/* General problems */
+	case T30_ERR_RETRYDCN:           /*! Disconnected after permitted retries */
+		ast_atomic_fetchadd_int(&p->stats->retries_exceeded, 1);
+		break;
+	case T30_ERR_CALLDROPPED:        /*! The call dropped prematurely */
+		ast_atomic_fetchadd_int(&p->stats->call_dropped, 1);
+		break;
+
+	/* Feature negotiation issues */
+	case T30_ERR_NOPOLL:             /*! Poll not accepted */
+	case T30_ERR_IDENT_UNACCEPTABLE: /*! Far end's ident is not acceptable */
+	case T30_ERR_SUB_UNACCEPTABLE:   /*! Far end's sub-address is not acceptable */
+	case T30_ERR_SEP_UNACCEPTABLE:   /*! Far end's selective polling address is not acceptable */
+	case T30_ERR_PSA_UNACCEPTABLE:   /*! Far end's polled sub-address is not acceptable */
+	case T30_ERR_SID_UNACCEPTABLE:   /*! Far end's sender identification is not acceptable */
+	case T30_ERR_PWD_UNACCEPTABLE:   /*! Far end's password is not acceptable */
+	case T30_ERR_TSA_UNACCEPTABLE:   /*! Far end's transmitting subscriber internet address is not acceptable */
+	case T30_ERR_IRA_UNACCEPTABLE:   /*! Far end's internet routing address is not acceptable */
+	case T30_ERR_CIA_UNACCEPTABLE:   /*! Far end's calling subscriber internet address is not acceptable */
+	case T30_ERR_ISP_UNACCEPTABLE:   /*! Far end's internet selective polling address is not acceptable */
+	case T30_ERR_CSA_UNACCEPTABLE:   /*! Far end's called subscriber internet address is not acceptable */
+		ast_atomic_fetchadd_int(&p->stats->neg_failed, 1);
+		break;
+	default:
+		ast_atomic_fetchadd_int(&p->stats->unknown_error, 1);
+		ast_log(LOG_WARNING, "unknown FAX session result '%d' (%s)\n", completion_code, t30_completion_code_to_str(completion_code));
+		return -1;
+	}
+	return 0;
+}
+
+/*! \brief Phase E handler callback.
+ * \param t30_state the span t30 state
+ * \param data this will be the ast_fax_session
+ * \param completion_code the result of the fax session
+ *
+ * This function pulls stats from the spandsp stack and stores them for res_fax
+ * to use later.
+ */
+static void t30_phase_e_handler(t30_state_t *t30_state, void *data, int completion_code)
+{
+	struct ast_fax_session *s = data;
+	struct spandsp_pvt *p = s->tech_pvt;
+	char headerinfo[T30_MAX_PAGE_HEADER_INFO + 1];
+	const char *c;
+	t30_stats_t stats;
+
+	ast_debug(5, "FAX session '%d' entering phase E\n", s->id);
+
+	p->isdone = 1;
+
+	update_stats(p, completion_code);
+
+	t30_get_transfer_statistics(t30_state, &stats);
+
+	if (completion_code == T30_ERR_OK) {
+		ast_string_field_set(s->details, result, "SUCCESS");
+	} else {
+		ast_string_field_set(s->details, result, "FAILED");
+		ast_string_field_set(s->details, error, t30_completion_code_to_str(completion_code));
+	}
+
+	ast_string_field_set(s->details, resultstr, t30_completion_code_to_str(completion_code));
+
+	ast_debug(5, "FAX session '%d' completed with result: %s (%s)\n", s->id, s->details->result, s->details->resultstr);
+
+	if ((c = t30_get_tx_ident(t30_state))) {
+		ast_string_field_set(s->details, localstationid, c);
+	}
+
+	if ((c = t30_get_rx_ident(t30_state))) {
+		ast_string_field_set(s->details, remotestationid, c);
+	}
+
+#if SPANDSP_RELEASE_DATE >= 20090220
+	s->details->pages_transferred = (s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_rx : stats.pages_tx;
+#else
+	s->details->pages_transferred = stats.pages_transferred;
+#endif
+
+	ast_string_field_build(s->details, transfer_rate, "%d", stats.bit_rate);
+
+	ast_string_field_build(s->details, resolution, "%dx%d", stats.x_resolution, stats.y_resolution);
+
+	t30_get_tx_page_header_info(t30_state, headerinfo);
+	ast_string_field_set(s->details, headerinfo, headerinfo);
+}
+
+/*! \brief Send spandsp log messages to asterisk.
+ * \param level the spandsp logging level
+ * \param msg the log message
+ *
+ * \note This function is a callback function called by spandsp.
+ */
+static void spandsp_log(int level, const char *msg)
+{
+	if (level == SPAN_LOG_ERROR) {
+		ast_log(LOG_ERROR, "%s", msg);
+	} else if (level == SPAN_LOG_WARNING) {
+		ast_log(LOG_WARNING, "%s", msg);
+	} else {
+		ast_log(LOG_DEBUG, "%s", msg);
+	}
+}
+
+static void set_logging(logging_state_t *state, struct ast_fax_session_details *details)
+{
+	int level = SPAN_LOG_WARNING;
+
+        if (details->option.debug) {
+		level = SPAN_LOG_DEBUG_3;
+	}
+
+	span_log_set_message_handler(state, spandsp_log);
+	span_log_set_level(state, SPAN_LOG_SHOW_SEVERITY | SPAN_LOG_SHOW_PROTOCOL | level);
+}
+
+static void set_local_info(t30_state_t *t30_state, struct ast_fax_session_details *details)
+{
+	if (!ast_strlen_zero(details->localstationid)) {
+		t30_set_tx_ident(t30_state, details->localstationid);
+	}
+
+	if (!ast_strlen_zero(details->headerinfo)) {
+		t30_set_tx_page_header_info(t30_state, details->headerinfo);
+	}
+}
+
+static void set_file(t30_state_t *t30_state, struct ast_fax_session_details *details)
+{
+	if (details->caps & AST_FAX_TECH_RECEIVE) {
+		t30_set_rx_file(t30_state, AST_LIST_FIRST(&details->documents)->filename, -1);
+	} else {
+		/* if not AST_FAX_TECH_RECEIVE, assume AST_FAX_TECH_SEND, this
+		 * should be safe because we ensure either RECEIVE or SEND is
+		 * indicated in spandsp_fax_new() */
+		t30_set_tx_file(t30_state, AST_LIST_FIRST(&details->documents)->filename, -1, -1);
+	}
+}
+
+static void set_ecm(t30_state_t *t30_state, struct ast_fax_session_details *details)
+{
+	t30_set_ecm_capability(t30_state, (details->option.ecm == AST_FAX_OPTFLAG_DEFAULT) ? 1 : details->option.ecm );
+	t30_set_supported_compressions(t30_state, T30_SUPPORT_T4_1D_COMPRESSION | T30_SUPPORT_T4_2D_COMPRESSION | T30_SUPPORT_T6_COMPRESSION);
+}
+
+/*! \brief create an instance of the spandsp tech_pvt for a fax session */
+static void *spandsp_fax_new(struct ast_fax_session *s, struct ast_fax_tech_token *token)
+{
+	struct spandsp_pvt *p;
+	int caller_mode;
+
+	if ((!(p = ast_calloc(1, sizeof(*p))))) {
+		ast_log(LOG_ERROR, "Cannot initialize the spandsp private FAX technology structure.\n");
+		goto e_return;
+	}
+
+	AST_LIST_HEAD_INIT(&p->read_frames);
+
+	if (s->details->caps & AST_FAX_TECH_RECEIVE) {
+		caller_mode = 0;
+	} else if (s->details->caps & AST_FAX_TECH_SEND) {
+		caller_mode = 1;
+	} else {
+		ast_log(LOG_ERROR, "Are we sending or receiving? The FAX requirements (capabilities: 0x%X) were not properly set.\n", s->details->caps);
+		goto e_free;
+	}
+
+	if (!(p->timer = ast_timer_open())) {
+		ast_log(LOG_ERROR, "Channel '%s' FAX session '%d' failed to create timing source.\n", s->channame, s->id);
+		goto e_free;
+	}
+
+	s->fd = ast_timer_fd(p->timer);
+
+	p->stats = &spandsp_global_stats.g711;
+
+	if (s->details->caps & AST_FAX_TECH_T38) {
+		if ((s->details->caps & AST_FAX_TECH_AUDIO) == 0) {
+			/* audio mode was not requested, start in T.38 mode */
+			p->ist38 = 1;
+			p->stats = &spandsp_global_stats.t38;
+		}
+
+		/* init t38 stuff */
+		t38_terminal_init(&p->t38_state, caller_mode, t38_tx_packet_handler, p);
+		set_logging(&p->t38_state.logging, s->details);
+	}
+
+	if (s->details->caps & AST_FAX_TECH_AUDIO) {
+		/* init audio stuff */
+		fax_init(&p->fax_state, caller_mode);
+		set_logging(&p->fax_state.logging, s->details);
+	}
+
+	s->state = AST_FAX_STATE_INITIALIZED;
+	return p;
+
+e_free:
+	ast_free(p);
+e_return:
+	return NULL;
+}
+
+/*! \brief Destroy a spandsp fax session.
+ */
+static void spandsp_fax_destroy(struct ast_fax_session *s)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+
+	session_destroy(p);
+	ast_free(p);
+	s->tech_pvt = NULL;
+	s->fd = -1;
+}
+
+/*! \brief Read a frame from the spandsp fax stack.
+ */
+static struct ast_frame *spandsp_fax_read(struct ast_fax_session *s)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+	uint8_t buffer[AST_FRIENDLY_OFFSET + SPANDSP_FAX_SAMPLES * sizeof(uint16_t)];
+	int16_t *buf = (int16_t *) (buffer + AST_FRIENDLY_OFFSET);
+	int samples;
+
+	struct ast_frame fax_frame = {
+		.frametype = AST_FRAME_VOICE,
+		.subclass.codec = AST_FORMAT_SLINEAR,
+		.src = "res_fax_spandsp_g711",
+	};
+
+	struct ast_frame *f = &fax_frame;
+
+	ast_timer_ack(p->timer, 1);
+
+	/* XXX do we need to lock here? */
+	if (p->isdone) {
+		s->state = AST_FAX_STATE_COMPLETE;
+		ast_debug(5, "FAX session '%d' is complete.\n", s->id);
+		return NULL;
+	}
+
+	if (p->ist38) {
+		t38_terminal_send_timeout(&p->t38_state, SPANDSP_FAX_SAMPLES);
+		if ((f = AST_LIST_REMOVE_HEAD(&p->read_frames, frame_list))) {
+			return f;
+		}
+	} else {
+		if ((samples = fax_tx(&p->fax_state, buf, SPANDSP_FAX_SAMPLES)) > 0) {
+			f->samples = samples;
+			AST_FRAME_SET_BUFFER(f, buffer, AST_FRIENDLY_OFFSET, samples * sizeof(int16_t));
+			return ast_frisolate(f);
+		}
+	}
+
+	return &ast_null_frame;
+}
+
+/*! \brief Write a frame to the spandsp fax stack.
+ * \param s a fax session
+ * \param f the frame to write
+ *
+ * \note res_fax does not currently use the return value of this function.
+ * Also the fax_rx() function never fails.
+ *
+ * \retval 0 success
+ * \retval -1 failure
+ */
+static int spandsp_fax_write(struct ast_fax_session *s, const struct ast_frame *f)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+
+	/* XXX do we need to lock here? */
+	if (s->state == AST_FAX_STATE_COMPLETE) {
+		ast_log(LOG_WARNING, "FAX session '%d' is in the '%s' state.\n", s->id, ast_fax_state_to_str(s->state));
+		return -1;
+	}
+
+	if (p->ist38) {
+		return t38_core_rx_ifp_packet(p->t38_core_state, f->data.ptr, f->datalen, f->seqno);
+	} else {
+		return fax_rx(&p->fax_state, f->data.ptr, f->samples);
+	}
+}
+
+/*! \brief */
+static int spandsp_fax_start(struct ast_fax_session *s)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+
+	s->state = AST_FAX_STATE_OPEN;
+
+	if (p->ist38) {
+#if SPANDSP_RELEASE_DATE >= 20080725
+		/* for spandsp shaphots 0.0.6 and higher */
+		p->t30_state = &p->t38_state.t30;
+		p->t38_core_state = &p->t38_state.t38_fe.t38;
+#else
+		/* for spandsp releases 0.0.5 */
+		p->t30_state = &p->t38_state.t30_state;
+		p->t38_core_state = &p->t38_state.t38;
+#endif
+	} else {
+#if SPANDSP_RELEASE_DATE >= 20080725
+		/* for spandsp shaphots 0.0.6 and higher */
+		p->t30_state = &p->fax_state.t30;
+#else
+		/* for spandsp release 0.0.5 */
+		p->t30_state = &p->fax_state.t30_state;
+#endif
+	}
+
+	set_logging(&p->t30_state->logging, s->details);
+
+	/* set some parameters */
+	set_local_info(p->t30_state, s->details);
+	set_file(p->t30_state, s->details);
+	set_ecm(p->t30_state, s->details);
+
+	/* perhaps set_transmit_on_idle() should be called */
+
+	t30_set_phase_e_handler(p->t30_state, t30_phase_e_handler, s);
+
+	/* set T.38 parameters */
+	if (p->ist38) {
+		set_logging(&p->t38_core_state->logging, s->details);
+
+		t38_set_max_datagram_size(p->t38_core_state, s->details->their_t38_parameters.max_ifp);
+
+		if (s->details->their_t38_parameters.fill_bit_removal) {
+			t38_set_fill_bit_removal(p->t38_core_state, TRUE);
+		}
+
+		if (s->details->their_t38_parameters.transcoding_mmr) {
+			t38_set_mmr_transcoding(p->t38_core_state, TRUE);
+		}
+
+		if (s->details->their_t38_parameters.transcoding_jbig) {
+			t38_set_jbig_transcoding(p->t38_core_state, TRUE);
+		}
+	} else {
+		/* have the fax stack generate silence if it has no data to send */
+		fax_set_transmit_on_idle(&p->fax_state, 1);
+	}
+
+
+	/* start the timer */
+	if (ast_timer_set_rate(p->timer, SPANDSP_FAX_TIMER_RATE)) {
+		ast_log(LOG_ERROR, "FAX session '%d' error setting rate on timing source.\n", s->id);
+		return -1;
+	}
+
+	s->state = AST_FAX_STATE_ACTIVE;
+
+	return 0;
+}
+
+/*! \brief */
+static int spandsp_fax_cancel(struct ast_fax_session *s)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+	t30_terminate(p->t30_state);
+	p->isdone = 1;
+	return 0;
+}
+
+/*! \brief */
+static int spandsp_fax_switch_to_t38(struct ast_fax_session *s)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+
+	/* prevent the phase E handler from running, this is not a real termination */
+	t30_set_phase_e_handler(p->t30_state, NULL, NULL);
+
+	t30_terminate(p->t30_state);
+
+	s->details->option.switch_to_t38 = 1;
+	ast_atomic_fetchadd_int(&p->stats->switched, 1);
+
+	p->ist38 = 1;
+	p->stats = &spandsp_global_stats.t38;
+	spandsp_fax_start(s);
+
+	return 0;
+}
+
+/*! \brief */
+static char *spandsp_fax_cli_show_capabilities(int fd)
+{
+	ast_cli(fd, "SEND RECEIVE T.38 G.711\n\n");
+	return  CLI_SUCCESS;
+}
+
+/*! \brief */
+static char *spandsp_fax_cli_show_session(struct ast_fax_session *s, int fd)
+{
+	struct spandsp_pvt *p = s->tech_pvt;
+	t30_stats_t stats;
+
+	ao2_lock(s);
+	ast_cli(fd, "%-22s : %d\n", "session", s->id);
+	ast_cli(fd, "%-22s : %s\n", "operation", (s->details->caps & AST_FAX_TECH_RECEIVE) ? "Receive" : "Transmit");
+	ast_cli(fd, "%-22s : %s\n", "state", ast_fax_state_to_str(s->state));
+	if (s->state != AST_FAX_STATE_UNINITIALIZED) {
+		t30_get_transfer_statistics(p->t30_state, &stats);
+		ast_cli(fd, "%-22s : %s\n", "Last Status", t30_completion_code_to_str(stats.current_status));
+		ast_cli(fd, "%-22s : %s\n", "ECM Mode", stats.error_correcting_mode ? "Yes" : "No");
+		ast_cli(fd, "%-22s : %d\n", "Data Rate", stats.bit_rate);
+		ast_cli(fd, "%-22s : %dx%d\n", "Image Resolution", stats.x_resolution, stats.y_resolution);
+#if SPANDSP_RELEASE_DATE >= 20090220
+		ast_cli(fd, "%-22s : %d\n", "Page Number", (s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_rx : stats.pages_tx);
+#else
+		ast_cli(fd, "%-22s : %d\n", "Page Number", stats.pages_transferred);
+#endif
+		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);
+
+		ast_cli(fd, "\nData Statistics:\n");
+#if SPANDSP_RELEASE_DATE >= 20090220
+		ast_cli(fd, "%-22s : %d\n", "Tx Pages", stats.pages_tx);
+		ast_cli(fd, "%-22s : %d\n", "Rx Pages", stats.pages_rx);
+#else
+		ast_cli(fd, "%-22s : %d\n", "Tx Pages", (s->details->caps & AST_FAX_TECH_SEND) ? stats.pages_transferred : 0);
+		ast_cli(fd, "%-22s : %d\n", "Rx Pages", (s->details->caps & AST_FAX_TECH_RECEIVE) ? stats.pages_transferred : 0);
+#endif
+		ast_cli(fd, "%-22s : %d\n", "Longest Bad Line Run", stats.longest_bad_row_run);
+		ast_cli(fd, "%-22s : %d\n", "Total Bad Lines", stats.bad_rows);
+	}
+	ao2_unlock(s);
+	ast_cli(fd, "\n\n");
+	return CLI_SUCCESS;
+}
+
+/*! \brief */
+static char *spandsp_fax_cli_show_stats(int fd)
+{
+	ast_mutex_lock(&spandsp_global_stats.lock);
+	ast_cli(fd, "\n%-20.20s\n", "Spandsp G.711");
+	ast_cli(fd, "%-20.20s : %d\n", "Success", spandsp_global_stats.g711.success);
+	ast_cli(fd, "%-20.20s : %d\n", "Switched to T.38", spandsp_global_stats.g711.switched);
+	ast_cli(fd, "%-20.20s : %d\n", "Call Dropped", spandsp_global_stats.g711.call_dropped);
+	ast_cli(fd, "%-20.20s : %d\n", "No FAX", spandsp_global_stats.g711.nofax);
+	ast_cli(fd, "%-20.20s : %d\n", "Negotation Failed", spandsp_global_stats.g711.neg_failed);
+	ast_cli(fd, "%-20.20s : %d\n", "Train Failure", spandsp_global_stats.g711.failed_to_train);
+	ast_cli(fd, "%-20.20s : %d\n", "Retries Exceeded", spandsp_global_stats.g711.retries_exceeded);
+	ast_cli(fd, "%-20.20s : %d\n", "Protocol Error", spandsp_global_stats.g711.protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "TX Protocol Error", spandsp_global_stats.g711.tx_protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "RX Protocol Error", spandsp_global_stats.g711.rx_protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "File Error", spandsp_global_stats.g711.file_error);
+	ast_cli(fd, "%-20.20s : %d\n", "Memory Error", spandsp_global_stats.g711.mem_error);
+	ast_cli(fd, "%-20.20s : %d\n", "Unknown Error", spandsp_global_stats.g711.unknown_error);
+
+	ast_cli(fd, "\n%-20.20s\n", "Spandsp T.38");
+	ast_cli(fd, "%-20.20s : %d\n", "Success", spandsp_global_stats.t38.success);
+	ast_cli(fd, "%-20.20s : %d\n", "Call Dropped", spandsp_global_stats.t38.call_dropped);
+	ast_cli(fd, "%-20.20s : %d\n", "No FAX", spandsp_global_stats.t38.nofax);
+	ast_cli(fd, "%-20.20s : %d\n", "Negotation Failed", spandsp_global_stats.t38.neg_failed);
+	ast_cli(fd, "%-20.20s : %d\n", "Train Failure", spandsp_global_stats.t38.failed_to_train);
+	ast_cli(fd, "%-20.20s : %d\n", "Retries Exceeded", spandsp_global_stats.t38.retries_exceeded);
+	ast_cli(fd, "%-20.20s : %d\n", "Protocol Error", spandsp_global_stats.t38.protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "TX Protocol Error", spandsp_global_stats.t38.tx_protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "RX Protocol Error", spandsp_global_stats.t38.rx_protocol_error);
+	ast_cli(fd, "%-20.20s : %d\n", "File Error", spandsp_global_stats.t38.file_error);
+	ast_cli(fd, "%-20.20s : %d\n", "Memory Error", spandsp_global_stats.t38.mem_error);
+	ast_cli(fd, "%-20.20s : %d\n", "Unknown Error", spandsp_global_stats.t38.unknown_error);
+	ast_mutex_unlock(&spandsp_global_stats.lock);
+
+	return CLI_SUCCESS;
+}
+
+/*! \brief unload res_fax_spandsp */
+static int unload_module(void)
+{
+	ast_fax_tech_unregister(&spandsp_fax_tech);
+	ast_mutex_destroy(&spandsp_global_stats.lock);
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+/*! \brief load res_fax_spandsp */
+static int load_module(void)
+{
+	ast_mutex_init(&spandsp_global_stats.lock);
+	spandsp_fax_tech.module = ast_module_info->self;
+	if (ast_fax_tech_register(&spandsp_fax_tech) < 0) {
+		ast_log(LOG_ERROR, "failed to register FAX technology\n");
+		return AST_MODULE_LOAD_DECLINE;
+	}
+
+	/* prevent logging to stderr */
+	span_set_message_handler(NULL);
+
+	return AST_MODULE_LOAD_SUCCESS;
+}
+
+
+AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Spandsp G.711 and T.38 FAX Technologies",
+		.load = load_module,
+		.unload = unload_module,
+	       );