Various changes from IAXmodem's spandsp made in the last few years.

configure.ac

@@ -558,6 +558,11 @@ AC_CHECK_LIB([tiff], [TIFFCreateCustomDirectory], [
 AC_CHECK_HEADERS([jpeglib.h])
 AC_CHECK_LIB([jpeg], [jpeg_start_compress], [JPEG_LIBS="-ljpeg"], AC_MSG_ERROR("Cannot build without libtiff (does your system require a libjpeg-devel or libjpeg-turbo-devel package?)"))
 
+AC_CHECK_LIB([ssl], [TLS_client_method], [
+    AC_DEFINE([SPANDSP_SUPPORT_FLEXSSL], [1], [Support flexible OpenSSL methods])
+    SPANDSP_SUPPORT_FLEXSSL="#define SPANDSP_SUPPORT_FLEXSSL 1"
+], [SPANDSP_SUPPORT_TIFF_FX="#undef SPANDSP_SUPPORT_FLEXSSL"], -lm)
+
 LIBS="$LIBS $TIFF_LIBS $JPEG_LIBS"
 
 TESTLIBS="$SIMLIBS $TESTLIBS"

src/Makefile.am

@@ -149,6 +149,7 @@ libspandsp_la_SOURCES = ademco_contactid.c \
                         schedule.c \
                         sig_tone.c \
                         silence_gen.c \
+                        sslfax.c \
                         super_tone_rx.c \
                         super_tone_tx.c \
                         swept_tone.c \
@@ -245,6 +246,7 @@ nobase_include_HEADERS = spandsp/ademco_contactid.h \
                          spandsp/stdbool.h \
                          spandsp/sig_tone.h \
                          spandsp/silence_gen.h \
+                         spandsp/sslfax.h \
                          spandsp/super_tone_rx.h \
                          spandsp/super_tone_tx.h \
                          spandsp/swept_tone.h \
@@ -320,6 +322,7 @@ nobase_include_HEADERS = spandsp/ademco_contactid.h \
                          spandsp/private/schedule.h \
                          spandsp/private/sig_tone.h \
                          spandsp/private/silence_gen.h \
+                         spandsp/private/sslfax.h \
                          spandsp/private/super_tone_rx.h \
                          spandsp/private/super_tone_tx.h \
                          spandsp/private/swept_tone.h \

src/at_interpreter.c

@@ -344,7 +344,6 @@ SPAN_DECLARE(void) at_call_event(at_state_t *s, int event)
         break;
     case AT_CALL_EVENT_HANGUP:
         span_log(&s->logging, SPAN_LOG_FLOW, "Hangup... at_rx_mode %d\n", s->at_rx_mode);
-        at_modem_control(s, AT_MODEM_CONTROL_ONHOOK, NULL);
         if (s->dte_is_waiting)
         {
             if (s->ok_is_pending)
@@ -369,6 +368,7 @@ SPAN_DECLARE(void) at_call_event(at_state_t *s, int event)
         if (s->at_rx_mode != AT_MODE_OFFHOOK_COMMAND  &&  s->at_rx_mode != AT_MODE_ONHOOK_COMMAND)
             at_put_response_code(s, AT_RESPONSE_CODE_NO_CARRIER);
         s->rx_signal_present = false;
+        at_modem_control(s, AT_MODEM_CONTROL_ONHOOK, NULL);
         at_modem_control(s, AT_MODEM_CONTROL_RNG, (void *) 0);
         at_set_at_rx_mode(s, AT_MODE_ONHOOK_COMMAND);
         break;
@@ -963,8 +963,6 @@ static const char *at_cmd_D(at_state_t *s, const char *t)
                 break;
             case '+':
                 /* V.250 6.3.1.1 International access code */
-                /* TODO: */
-                break;
             case ',':
                 /* V.250 6.3.1.2 Pause */
                 /* Pass these through to the application to handle. */

src/fax.c

@@ -247,13 +247,35 @@ SPAN_DECLARE(int) fax_tx(fax_state_t *s, int16_t *amp, int max_len)
 }
 /*- End of function --------------------------------------------------------*/
 
+static int fax_get_phase(void *user_data)
+{
+    t30_state_t *s = user_data;
+    return s->phase;
+}
+
 static void fax_set_rx_type(void *user_data, int type, int bit_rate, int short_train, int use_hdlc)
 {
     fax_state_t *s;
     fax_modems_state_t *t;
 
     s = (fax_state_t *) user_data;
     t = &s->modems;
+
+    if (s->t30.sslfax.server && type != T30_MODEM_DONE)
+    {
+        span_log(&s->logging, SPAN_LOG_FLOW, "Set fallback rx type %d%s\n", type, use_hdlc ? " (HDLC)" : "");
+        fax_modems_set_rx_handler(t, (span_rx_handler_t) &sslfax_rx, &s->t30.sslfax, (span_rx_fillin_handler_t) NULL, &s->t30.sslfax);
+        sslfax_setup(&s->t30.sslfax, &s->t30, t30_non_ecm_put, t30_non_ecm_get, t30_hdlc_accept, hdlc_underflow_handler, s->t30.sslfax.tx_use_hdlc, use_hdlc, fax_get_phase);
+        t->rx_bit_rate = bit_rate;
+        t->current_rx_type = type;
+        if (use_hdlc)
+        {
+            t30_hdlc_accept(&s->t30, NULL, SIG_STATUS_CARRIER_UP, true);
+            t30_hdlc_accept(&s->t30, NULL, SIG_STATUS_FRAMING_OK, true);
+        }
+        return;
+    }
+
     span_log(&s->logging, SPAN_LOG_FLOW, "Set rx type %d\n", type);
     if (t->current_rx_type == type)
         return;
@@ -295,6 +317,19 @@ static void fax_set_tx_type(void *user_data, int type, int bit_rate, int short_t
 
     s = (fax_state_t *) user_data;
     t = &s->modems;
+
+    if (s->t30.sslfax.server && type != T30_MODEM_DONE)
+    {
+        span_log(&s->logging, SPAN_LOG_FLOW, "Set fallback tx type %d%s\n", type, use_hdlc ? " (HDLC)" : "");
+        fax_modems_set_tx_handler(t, (span_tx_handler_t) &sslfax_tx, &s->t30.sslfax);
+        fax_modems_set_next_tx_handler(t, (span_tx_handler_t) &sslfax_tx, &s->t30.sslfax);
+        sslfax_setup(&s->t30.sslfax, &s->t30, t30_non_ecm_put, t30_non_ecm_get, t30_hdlc_accept, hdlc_underflow_handler, use_hdlc, s->t30.sslfax.rx_use_hdlc, fax_get_phase);
+        t->transmit = true;
+        t->tx_bit_rate = bit_rate;
+        t->current_tx_type = type;
+        return;
+    }
+
     span_log(&s->logging, SPAN_LOG_FLOW, "Set tx type %d\n", type);
     if (t->current_tx_type == type)
         return;

src/spandsp.h.in

@@ -109,6 +109,7 @@
 #include <spandsp/v42bis.h>
 #include <spandsp/v18.h>
 #include <spandsp/timezone.h>
+#include <spandsp/sslfax.h>
 #include <spandsp/t4_rx.h>
 #include <spandsp/t4_tx.h>
 #include <spandsp/image_translate.h>

src/spandsp/expose.h

@@ -85,6 +85,7 @@
 #include <spandsp/private/data_modems.h>
 #include <spandsp/private/fax_modems.h>
 #include <spandsp/private/timezone.h>
+#include <spandsp/private/sslfax.h>
 #include <spandsp/private/image_translate.h>
 #include <spandsp/private/t4_t6_decode.h>
 #include <spandsp/private/t4_t6_encode.h>

src/spandsp/private/sslfax.h

@@ -0,0 +1,123 @@
+/*
+ * The code in this file was derived from sources taken from (1) HylaFAX+ on
+ * 13 June 2022. That source states that it was derived from (2) GitHub user,
+ * "mrwicks", on 9 Oct 2018.  That source, itself, was derived from work by
+ * "Amlendra" published at Aticleworld on 21 May 2017 (3).  That work, then,
+ * references programs (4) Copyright (c) 2000 Sean Walton and Macmillan
+ * Publishers (The "Linux Socket Programming" book) and are licensed under
+ * the GPL.
+ *
+ * 1. https://hylafax.sourceforge.net
+ * 2. https://github.com/mrwicks/miscellaneous/tree/master/tls_1.2_example
+ * 3. https://aticleworld.com/ssl-server-client-using-openssl-in-c/
+ * 4. http://www.cs.utah.edu/~swalton/listings/sockets/programs/
+ *
+ * It is, therefore, presumed that this work is either under the* public
+ * domain or is licensed under the GPL.  A copy of the GPL is as follows...
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+//#ifndef __sslfax_H
+//#define __sslfax_H
+//
+//#include <errno.h>
+//#include <unistd.h>
+//#include <string.h>
+//#include <arpa/inet.h>
+//#include <sys/socket.h>
+//#include <sys/types.h>
+//#include <netinet/in.h>
+//#include <resolv.h>
+//#include <stdio.h>
+//#include <netdb.h>
+//#include <openssl/ssl.h>
+//#include <openssl/err.h>
+//
+//#include "Str.h"
+//
+//struct SSLFaxProcess {
+//    SSL_CTX *ctx;
+//    SSL *ssl;
+//    int server;
+//    int client;
+//    fxStr emsg;		// error message
+//};
+//
+//struct SSLFax {
+//public:
+//    int getAddressFamily(fxStr& address);
+//    SSLFaxProcess null();
+//    SSLFaxProcess startServer(fxStr info, fxStr pemFile);
+//    SSLFaxProcess startClient(fxStr info, fxStr passcode, const u_char* bitrev, long ms);
+//    void acceptClient(SSLFaxProcess& sfp, fxStr passcode, int modemFd, long ms);
+//    bool acceptClient1(SSLFaxProcess& sfp, long ms, bool sustain = false);
+//    void acceptClient2(SSLFaxProcess& sfp, fxStr passcode, int modemFd, long ms, bool sustain = false);
+//    void cleanup(SSLFaxProcess& sfp, bool sustain = false);
+//    int pending(SSLFaxProcess& sfp);
+//    int read(SSLFaxProcess& sfp, void *buf, size_t count, int modemFd, long ms, bool sustain = false, bool carryon = false);
+//    int write(SSLFaxProcess& sfp, const u_char *buf, u_int count, const u_char* bitrev, int modemFd, long ms, bool eod, bool sustain = false);
+//};
+//
+//#endif
+
+/*! \file */
+
+#if !defined(_SPANDSP_PRIVATE_SSLFAX_H_)
+#define _SPANDSP_PRIVATE_SSLFAX_H_
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+
+/*!
+    SSL Fax connection descriptor. This defines the state of a single
+    instance of an SSL Fax connection.
+*/
+struct sslfax_state_s
+{
+    /*! \brief The remote SSL Fax URL, if known, else NULL. */
+    char* url;
+    SSL_CTX *ctx;
+    SSL *ssl;
+    int server;
+    int client;
+    int rcp_count;
+    int ecm_ones;
+    int ecm_bitpos;
+    uint8_t ecm_byte;
+    bool doread;
+    int signal;
+    bool do_underflow;
+    bool cleanup;
+
+    get_byte_func_t get_phase;
+
+    /*! \brief A user specified opaque pointer passed to the put, get, and hdlc routines. */
+    void *msg_user_data;
+    /*! \brief The callback function used to get bytes to be transmitted. */
+    get_msg_func_t get_msg;
+    /*! \brief The callback function used to put bytes received. */
+    put_msg_func_t put_msg;
+    /*! \brief The callback function used to accept HDLC frames. */
+    hdlc_frame_handler_t hdlc_accept;
+    /*! \brief The callback function used for HDLC underflow indication. */
+    hdlc_underflow_handler_t hdlc_tx_underflow;
+    /*! \brief Whether or not the data represents HDLC or not. */
+    bool tx_use_hdlc;
+    bool rx_use_hdlc;
+
+    /*! \brief Error and flow logging control */
+    logging_state_t logging;
+};
+
+#endif
+/*- End of file ------------------------------------------------------------*/

src/spandsp/private/t30.h

@@ -28,6 +28,8 @@
 #if !defined(_SPANDSP_PRIVATE_T30_H_)
 #define _SPANDSP_PRIVATE_T30_H_
 
+#include "spandsp/private/sslfax.h"
+
 /*!
     T.30 FAX channel descriptor. This defines the state of a single working
     instance of a T.30 FAX channel.
@@ -51,6 +53,8 @@ struct t30_state_s
 
     /*! \brief Internet aware FAX mode bit mask. */
     int iaf;
+    /*! \brief SSL Fax context. */
+    sslfax_state_t sslfax;
     /*! \brief A bit mask of the currently supported modem types. */
     int supported_modems;
     /*! \brief A bit mask of the currently supported image compression modes for use

src/spandsp/sslfax.h

@@ -0,0 +1,71 @@
+/*
+ * The code in this file was derived from sources taken from (1) HylaFAX+ on
+ * 13 June 2022. That source states that it was derived from (2) GitHub user,
+ * "mrwicks", on 9 Oct 2018.  That source, itself, was derived from work by
+ * "Amlendra" published at Aticleworld on 21 May 2017 (3).  That work, then,
+ * references programs (4) Copyright (c) 2000 Sean Walton and Macmillan
+ * Publishers (The "Linux Socket Programming" book) and are licensed under
+ * the GPL.
+ *
+ * 1. https://hylafax.sourceforge.net
+ * 2. https://github.com/mrwicks/miscellaneous/tree/master/tls_1.2_example
+ * 3. https://aticleworld.com/ssl-server-client-using-openssl-in-c/
+ * 4. http://www.cs.utah.edu/~swalton/listings/sockets/programs/
+ *
+ * It is, therefore, presumed that this work is either under the* public
+ * domain or is licensed under the GPL.  A copy of the GPL is as follows...
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+/*! \file */
+
+#if !defined(_SPANDSP_SSLFAX_H_)
+#define _SPANDSP_SSLFAX_H_
+
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+
+#include "spandsp/telephony.h"
+#include "spandsp/async.h"
+#include "spandsp/hdlc.h"
+
+typedef struct sslfax_state_s sslfax_state_t;
+
+#if defined(__cplusplus)
+extern "C"
+{
+#endif
+
+SPAN_DECLARE(sslfax_state_t *) sslfax_init(sslfax_state_t *s);
+
+SPAN_DECLARE(bool) sslfax_start_client(sslfax_state_t *s);
+
+SPAN_DECLARE(void) sslfax_cleanup(sslfax_state_t *s, bool sustain);
+
+SPAN_DECLARE(int) sslfax_tx(sslfax_state_t *s, int16_t amp[], int len);
+
+SPAN_DECLARE(int) sslfax_rx(sslfax_state_t *s, const int16_t amp[], int len);
+
+SPAN_DECLARE(void) sslfax_setup(sslfax_state_t *s, void *msg_user_data, put_msg_func_t put_msg, get_msg_func_t get_msg, hdlc_frame_handler_t hdlc_accept, hdlc_underflow_handler_t hdlc_tx_underflow, bool tx_use_hdlc, bool rx_use_hdlc, get_byte_func_t get_phase);
+
+SPAN_DECLARE(int) sslfax_write(sslfax_state_t *s, const u_char *buf, u_int count, int modemFd, long ms, bool filter, bool sustain);
+
+SPAN_DECLARE(int) sslfax_read(sslfax_state_t *s, void *buf, size_t count, int modemFd, long ms, bool sustain, bool carryon);
+
+#if defined(__cplusplus)
+}
+#endif
+
+
+#endif
+/*- End of file ------------------------------------------------------------*/

src/spandsp/t30.h

@@ -28,6 +28,8 @@
 #if !defined(_SPANDSP_T30_H_)
 #define _SPANDSP_T30_H_
 
+#include "spandsp/sslfax.h"
+
 /*! \page t30_page T.30 FAX protocol handling
 
 \section t30_page_sec_1 What does it do?

src/spandsp/t30_api.h

@@ -454,8 +454,8 @@ SPAN_DECLARE(void) t30_set_tx_file(t30_state_t *s, const char *file, int start_p
 /*! Set Internet aware FAX (IAF) mode.
     \brief Set Internet aware FAX (IAF) mode.
     \param s The T.30 context.
-    \param iaf True for IAF, or false for non-IAF. */
-SPAN_DECLARE(void) t30_set_iaf_mode(t30_state_t *s, bool iaf);
+    \param iaf Bitmap for IAF values. */
+SPAN_DECLARE(void) t30_set_iaf_mode(t30_state_t *s, int iaf);
 
 /*! Specify if error correction mode (ECM) is allowed by a T.30 context.
     \brief Select ECM capability.
@@ -464,6 +464,12 @@ SPAN_DECLARE(void) t30_set_iaf_mode(t30_state_t *s, bool iaf);
     \return 0 if OK, else -1. */
 SPAN_DECLARE(int) t30_set_ecm_capability(t30_state_t *s, bool enabled);
 
+/*! Specify if page retransmission is allowed by a T.30 context.
+    \brief Select page regtransmission capable.
+    \param s The T.30 context.
+    \param enabled True for retransmit capable, or false for not retransmit capable. */
+SPAN_DECLARE(void) t30_set_retransmit_capable(t30_state_t *s, bool enabled);
+
 /*! Specify the output encoding for TIFF files created during FAX reception.
     \brief Specify the output encoding for TIFF files created during FAX reception.
     \param s The T.30 context.