Add dynamic fax buffer configuration option to chan_dahdi.conf

When the 'faxdetect' configuration option is used, one may also want to use
the 'faxbuffers' configuration option in chan_dahdi.conf.  This option will
dynamically use the configured 'faxbuffers' buffer policy on a channel for
the life of the call following the detection of fax tones.  The faxbuffers
buffer policy will be reverted during call teardown.

An example use of 'faxbuffers' is below.  This example would switch to using
6 buffers with a full buffer policy.

faxbuffers=>6,full


git-svn-id: http://svn.digium.com/svn/asterisk/trunk@175411 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 75 insertions, 2 deletions

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index db2f842aa..e0166f45a 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -583,8 +583,11 @@ static struct dahdi_pvt {
 	struct dahdi_pvt *master;				/*!< Master to us (we follow their conferencing) */
 	int inconference;				/*!< If our real should be in the conference */
 
+	int bufsize;                /*!< Size of the buffers */
 	int buf_no;					/*!< Number of buffers */
 	int buf_policy;				/*!< Buffer policy */
+	int faxbuf_no;              /*!< Number of Fax buffers */
+	int faxbuf_policy;          /*!< Fax buffer policy */
 	int sig;					/*!< Signalling style */
 	/*!
 	 * \brief Nonzero if the signaling type is sent over a radio.
@@ -681,6 +684,10 @@ static struct dahdi_pvt {
 	unsigned int echocanon:1;
 	/*! \brief TRUE if a fax tone has already been handled. */
 	unsigned int faxhandled:1;
+	/*! \brief TRUE if dynamic faxbuffers are configured for use, default is OFF */
+	unsigned int usefaxbuffers:1;
+	/*! \brief TRUE while dynamic faxbuffers are in use */
+	unsigned int faxbuffersinuse:1;
 	/*! \brief TRUE if over a radio and dahdi_read() has been called. */
 	unsigned int firstradio:1;
 	/*!
@@ -1233,7 +1240,10 @@ static struct dahdi_chan_conf dahdi_chan_conf_default(void)
 			.sendcalleridafter = DEFAULT_CIDRINGS,
 
 			.buf_policy = DAHDI_POLICY_IMMEDIATE,
-			.buf_no = numbufs
+			.buf_no = numbufs,
+			.usefaxbuffers = 0,
+			.faxbuf_policy = DAHDI_POLICY_IMMEDIATE,
+			.faxbuf_no = numbufs,
 		},
 		.timing = {
 			.prewinktime = -1,
@@ -3715,6 +3725,22 @@ static int dahdi_hangup(struct ast_channel *ast)
 			p->dsp = NULL;
 		}
 
+		if (p->faxbuffersinuse) {
+			/* faxbuffers are in use, revert them */
+			struct dahdi_bufferinfo bi = {
+				.txbufpolicy = p->buf_policy,
+				.rxbufpolicy = p->buf_policy,
+				.bufsize = p->bufsize,
+				.numbufs = p->buf_no
+			};
+			int bpres;
+
+			if ((bpres = ioctl(p->subs[SUB_REAL].dfd, DAHDI_SET_BUFINFO, &bi)) < 0) {
+				ast_log(LOG_WARNING, "Channel '%s' unable to revert faxbuffer policy: %s\n", ast->name, strerror(errno));
+			}
+			p->faxbuffersinuse = 0;	
+		}
+
 		law = DAHDI_LAW_DEFAULT;
 		res = ioctl(p->subs[SUB_REAL].dfd, DAHDI_SETLAW, &law);
 		if (res < 0)
@@ -4803,6 +4829,21 @@ static void dahdi_handle_dtmfup(struct ast_channel *ast, int idx, struct ast_fra
 	} else if (f->subclass == 'f') {
 		/* Fax tone -- Handle and return NULL */
 		if ((p->callprogress & CALLPROGRESS_FAX) && !p->faxhandled) {
+			/* If faxbuffers are configured, use them for the fax transmission */
+			if (p->usefaxbuffers && !p->faxbuffersinuse) {
+				struct dahdi_bufferinfo bi = {
+					.txbufpolicy = p->faxbuf_policy,
+					.bufsize = p->bufsize,
+					.numbufs = p->faxbuf_no
+				};
+				int res;
+			
+				if ((res = ioctl(p->subs[idx].dfd, DAHDI_SET_BUFINFO, &bi)) < 0) {
+					ast_log(LOG_WARNING, "Channel '%s' unable to set faxbuffer policy, reason: %s\n", ast->name, strerror(errno));
+				} else {
+					p->faxbuffersinuse = 1;
+				}
+			}
 			p->faxhandled = 1;
 			if (strcmp(ast->exten, "fax")) {
 				const char *target_context = S_OR(ast->macrocontext, ast->context);
@@ -9276,8 +9317,19 @@ static struct dahdi_pvt *mkintf(int channel, const struct dahdi_chan_conf *conf,
 				if (res < 0) {
 					ast_log(LOG_WARNING, "Unable to set buffer policy on channel %d: %s\n", channel, strerror(errno));
 				}
-			} else
+			} else {
 				ast_log(LOG_WARNING, "Unable to check buffer policy on channel %d: %s\n", channel, strerror(errno));
+			}
+			tmp->buf_policy = conf->chan.buf_policy;
+			tmp->buf_no = conf->chan.buf_no;
+			tmp->usefaxbuffers = conf->chan.usefaxbuffers;
+			tmp->faxbuf_policy = conf->chan.faxbuf_policy;
+			tmp->faxbuf_no = conf->chan.faxbuf_no;
+			/* This is not as gnarly as it may first appear.  If the ioctl above failed, we'd be setting
+			 * tmp->bufsize to zero which would cause subsequent faxbuffer-related ioctl calls to fail.
+			 * The reason the ioctl call above failed should to be determined before worrying about the
+			 * faxbuffer-related ioctl calls */
+			tmp->bufsize = bi.bufsize;
 		}
 #endif
 		tmp->immediate = conf->chan.immediate;
@@ -14490,6 +14542,27 @@ static int process_dahdi(struct dahdi_chan_conf *confp, const char *cat, struct
 			} else {
 				ast_log(LOG_WARNING, "Invalid policy name given (%s).\n", policy);
 			}
+		} else if (!strcasecmp(v->name, "faxbuffers")) {
+			int res;
+			char policy[21] = "";
+
+			res = sscanf(v->value, "%d,%20s", &confp->chan.faxbuf_no, policy);
+			if (res != 2) {
+				ast_log(LOG_WARNING, "Parsing faxbuffers option data failed, using defaults.\n");
+				confp->chan.faxbuf_no = numbufs;
+				continue;
+			}
+			confp->chan.usefaxbuffers = 1;
+			if (confp->chan.faxbuf_no < 0)
+				confp->chan.faxbuf_no = numbufs;
+			if (!strcasecmp(policy, "full")) {
+				confp->chan.faxbuf_policy = DAHDI_POLICY_WHEN_FULL;
+			} else if (!strcasecmp(policy, "immediate")) {
+				confp->chan.faxbuf_policy = DAHDI_POLICY_IMMEDIATE;
+			} else {
+				ast_log(LOG_WARNING, "Invalid policy name given (%s).\n", policy);
+				confp->chan.usefaxbuffers = 0;
+			}
  		} else if (!strcasecmp(v->name, "dahdichan")) {
  			ast_copy_string(dahdichan, v->value, sizeof(dahdichan));
 		} else if (!strcasecmp(v->name, "usedistinctiveringdetection")) {