FreeTDM: Improve error checking and logging in load_config(), add FTDM_SPAN_IS_DIGITAL() helper.

Output the current trunk_type in "add X-channel vs. trunk_type" error messages and
check this for B-/D-channels too.

ISDN (= digital) spans need to have a trunk_type set before adding channels,
bail out early with an error message (actually two) if this is not the case.

(Adding channels should really be moved out of the parsing loop, to catch
 certain types of errors easier.)
Signed-off-by: Stefan Knoblich <stkn@openisdn.net>

libs/freetdm/src/ftdm_io.c

@@ -4764,7 +4764,7 @@ static ftdm_status_t load_config(void)
 						configured += chans_configured;
 					}
 				} else {
-					ftdm_log(FTDM_LOG_WARNING, "Cannot add FXO channels to an FXS trunk!\n");
+					ftdm_log(FTDM_LOG_WARNING, "Cannot add FXO channels to a %s trunk!\n", ftdm_trunk_type2str(span->trunk_type));
 				}
 			} else if (!strcasecmp(var, "fxs-channel")) {
 				if (span->trunk_type == FTDM_TRUNK_NONE) {
@@ -4780,7 +4780,7 @@ static ftdm_status_t load_config(void)
 						configured += chans_configured;
 					}
 				} else {
-					ftdm_log(FTDM_LOG_WARNING, "Cannot add FXS channels to an FXO trunk!\n");
+					ftdm_log(FTDM_LOG_WARNING, "Cannot add FXS channels to a %s trunk!\n", ftdm_trunk_type2str(span->trunk_type));
 				}
 			} else if (!strcasecmp(var, "em-channel")) {
 				if (span->trunk_type == FTDM_TRUNK_NONE) {
@@ -4796,19 +4796,33 @@ static ftdm_status_t load_config(void)
 						configured += chans_configured;
 					}
 				} else {
-					ftdm_log(FTDM_LOG_WARNING, "Cannot add EM channels to a non-EM trunk!\n");
+					ftdm_log(FTDM_LOG_WARNING, "Cannot add EM channels to a %s trunk!\n", ftdm_trunk_type2str(span->trunk_type));
 				}
 			} else if (!strcasecmp(var, "b-channel")) {
-				unsigned chans_configured = 0;
-				chan_config.type = FTDM_CHAN_TYPE_B;
-				if (ftdm_configure_span_channels(span, val, &chan_config, &chans_configured) == FTDM_SUCCESS) {
-					configured += chans_configured;
+				if (span->trunk_type == FTDM_TRUNK_NONE) {
+					ftdm_log(FTDM_LOG_ERROR, "No trunk type specified in configuration file\n");
+					break;
 				}
-			} else if (!strcasecmp(var, "d-channel")) {
-				if (d) {
-					ftdm_log(FTDM_LOG_WARNING, "ignoring extra d-channel\n");
+				if (FTDM_SPAN_IS_DIGITAL(span)) {
+					unsigned chans_configured = 0;
+					chan_config.type = FTDM_CHAN_TYPE_B;
+					if (ftdm_configure_span_channels(span, val, &chan_config, &chans_configured) == FTDM_SUCCESS) {
+						configured += chans_configured;
+					}
 				} else {
+					ftdm_log(FTDM_LOG_WARNING, "Cannot add B channels to a %s trunk!\n", ftdm_trunk_type2str(span->trunk_type));
+				}
+			} else if (!strcasecmp(var, "d-channel")) {
+				if (span->trunk_type == FTDM_TRUNK_NONE) {
+					ftdm_log(FTDM_LOG_ERROR, "No trunk type specified in configuration file\n");
+					break;
+				}
+				if (FTDM_SPAN_IS_DIGITAL(span)) {
 					unsigned chans_configured = 0;
+					if (d) {
+						ftdm_log(FTDM_LOG_WARNING, "ignoring extra d-channel\n");
+						continue;
+					}
 					if (!strncasecmp(val, "lapd:", 5)) {
 						chan_config.type = FTDM_CHAN_TYPE_DQ931;
 						val += 5;
@@ -4819,6 +4833,8 @@ static ftdm_status_t load_config(void)
 						configured += chans_configured;
 					}
 					d++;
+				} else {
+					ftdm_log(FTDM_LOG_WARNING, "Cannot add D channels to a %s trunk!\n", ftdm_trunk_type2str(span->trunk_type));
 				}
 			} else if (!strcasecmp(var, "cas-channel")) {
 				unsigned chans_configured = 0;

libs/freetdm/src/include/freetdm.h

@@ -204,6 +204,15 @@ FTDM_STR2ENUM_P(ftdm_str2ftdm_chan_type, ftdm_chan_type2str, ftdm_chan_type_t)
 	                                (fchan)->span->trunk_type == FTDM_TRUNK_BRI || \
 	                                (fchan)->span->trunk_type == FTDM_TRUNK_BRI_PTMP)
 
+/*! \brief Test if a span is digital */
+#define FTDM_SPAN_IS_DIGITAL(span) \
+	((span)->trunk_type == FTDM_TRUNK_E1 || \
+	 (span)->trunk_type == FTDM_TRUNK_T1 || \
+	 (span)->trunk_type == FTDM_TRUNK_J1 || \
+	 (span)->trunk_type == FTDM_TRUNK_BRI || \
+	 (span)->trunk_type == FTDM_TRUNK_BRI_PTMP)
+
+
 /*! \brief Logging function prototype to be used for all FreeTDM logs 
  *  you should use ftdm_global_set_logger to set your own logger
  */