Allow PRI to support callback functions (Diana's patch, placed in public domain)

git-svn-id: https://origsvn.digium.com/svn/libpri/trunk@202 2fbb986a-6c06-0410-b554-c9c1f0a7f128

libpri.h

@@ -376,6 +376,9 @@ typedef union {
 struct pri;
 struct pri_sr;
 
+#define PRI_IO_FUNCS
+/* Type declaration for callbacks to read or write a HDLC frame as below */
+typedef int (*pri_io_cb)(struct pri *pri, void *buf, int buflen);
 
 /* Create a D-channel on a given file descriptor.  The file descriptor must be a
    channel operating in HDLC mode with FCS computed by the fd's driver.  Also it
@@ -383,6 +386,15 @@ struct pri_sr;
    must be one of PRI_NETWORK or PRI_CPE.  switchtype should be PRI_SWITCH_* */
 extern struct pri *pri_new(int fd, int nodetype, int switchtype);
 
+/* Create D-channel just as above with user defined I/O callbacks and data */
+extern struct pri *pri_new_cb(int fd, int nodetype, int switchtype, pri_io_cb io_read, pri_io_cb io_write, void *userdata);
+
+/* Retrieve the user data associated with the D channel */
+extern void *pri_get_userdata(struct pri *pri);
+
+/* Set the user data associated with the D channel */
+extern void pri_set_userdata(struct pri *pri, void *userdata);
+
 /* Set Network Specific Facility for PRI */
 extern void pri_set_nsf(struct pri *pri, int nsf);
 

pri.c

@@ -153,13 +153,38 @@ int pri_timer2idx(char *timer)
 		return -1;
 }
 
-static struct pri *__pri_new(int fd, int node, int switchtype, struct pri *master)
+static int __pri_read(struct pri *pri, void *buf, int buflen)
+{
+	int res = read(pri->fd, buf, buflen);
+	if (res < 0) {
+		if (errno != EAGAIN)
+			pri_error("Read on %d failed: %s\n", pri->fd, strerror(errno));
+		return 0;
+	}
+	return res;
+}
+
+static int __pri_write(struct pri *pri, void *buf, int buflen)
+{
+	int res = write(pri->fd, buf, buflen);
+	if (res < 0) {
+		if (errno != EAGAIN)
+			pri_error("Write to %d failed: %s\n", pri->fd, strerror(errno));
+		return 0;
+	}
+	return res;
+}
+
+static struct pri *__pri_new(int fd, int node, int switchtype, struct pri *master, pri_io_cb rd, pri_io_cb wr, void *userdata)
 {
 	struct pri *p;
 	p = malloc(sizeof(struct pri));
 	if (p) {
 		memset(p, 0, sizeof(struct pri));
 		p->fd = fd;
+		p->read_func = rd;
+		p->write_func = wr;
+		p->userdata = userdata;
 		p->localtype = node;
 		p->switchtype = switchtype;
 		p->cref = 1;
@@ -180,7 +205,7 @@ static struct pri *__pri_new(int fd, int node, int switchtype, struct pri *maste
 			p->protodisc = GR303_PROTOCOL_DISCRIMINATOR;
 			p->sapi = Q921_SAPI_GR303_EOC;
 			p->tei = Q921_TEI_GR303_EOC_OPS;
-			p->subchannel = __pri_new(-1, node, PRI_SWITCH_GR303_EOC_PATH, p);
+			p->subchannel = __pri_new(-1, node, PRI_SWITCH_GR303_EOC_PATH, p, NULL, NULL, NULL);
 			if (!p->subchannel) {
 				free(p);
 				p = NULL;
@@ -189,7 +214,7 @@ static struct pri *__pri_new(int fd, int node, int switchtype, struct pri *maste
 			p->protodisc = GR303_PROTOCOL_DISCRIMINATOR;
 			p->sapi = Q921_SAPI_GR303_TMC_CALLPROC;
 			p->tei = Q921_TEI_GR303_TMC_CALLPROC;
-			p->subchannel = __pri_new(-1, node, PRI_SWITCH_GR303_TMC_SWITCHING, p);
+			p->subchannel = __pri_new(-1, node, PRI_SWITCH_GR303_TMC_SWITCHING, p, NULL, NULL, NULL);
 			if (!p->subchannel) {
 				free(p);
 				p = NULL;
@@ -210,9 +235,29 @@ static struct pri *__pri_new(int fd, int node, int switchtype, struct pri *maste
 	return p;
 }
 
-struct pri *pri_new(int fd, int node, int switchtype)
+struct pri *pri_new(int fd, int nodetype, int switchtype)
 {
-	return __pri_new(fd, node, switchtype, NULL);
+	return __pri_new(fd, nodetype, switchtype, NULL, __pri_read, __pri_write, NULL);
+}
+
+struct pri *pri_new_cb(int fd, int nodetype, int switchtype, pri_io_cb io_read, pri_io_cb io_write, void *userdata)
+{
+	if (!io_read)
+		io_read = __pri_read;
+	if (!io_write)
+		io_write = __pri_write;
+	return __pri_new(fd, nodetype, switchtype, NULL, io_read, io_write, userdata);
+}
+
+void *pri_get_userdata(struct pri *pri)
+{
+	return pri ? pri->userdata : NULL;
+}
+
+void pri_set_userdata(struct pri *pri, void *userdata)
+{
+	if (pri)
+		pri->userdata = userdata;
 }
 
 void pri_set_nsf(struct pri *pri, int nsf)
@@ -268,12 +313,7 @@ pri_event *pri_check_event(struct pri *pri)
 	char buf[1024];
 	int res;
 	pri_event *e;
-	res = read(pri->fd, buf, sizeof(buf));
-	if (res < 0) {
-		if (errno != EAGAIN)
-			pri_error("Read on %d failed: %s\n", pri->fd, strerror(errno));
-		return NULL;
-	}
+	res = pri->read_func ? pri->read_func(pri, buf, sizeof(buf)) : 0;
 	if (!res)
 		return NULL;
 	/* Receive the q921 packet */

pri_internal.h

@@ -44,6 +44,9 @@ enum q931_mode;
 
 struct pri {
 	int fd;				/* File descriptor for D-Channel */
+	pri_io_cb read_func;		/* Read data callback */
+	pri_io_cb write_func;		/* Write data callback */
+	void *userdata;
 	struct pri *subchannel;	/* Sub-channel if appropriate */
 	struct pri *master;		/* Master channel if appropriate */
 	struct pri_sched pri_sched[MAX_SCHED];	/* Scheduled events */

q921.c

@@ -83,7 +83,7 @@ static int q921_transmit(struct pri *pri, q921_h *h, int len)
 	if (pri->debug & PRI_DEBUG_Q921_DUMP)
 		q921_dump(h, len, pri->debug & PRI_DEBUG_Q921_RAW, 1);
 	/* Write an extra two bytes for the FCS */
-	res = write(pri->fd, h, len + 2);
+	res = pri->write_func ? pri->write_func(pri, h, len + 2) : 0;
 	if (res != (len + 2)) {
 		pri_error("Short write: %d/%d (%s)\n", res, len + 2, strerror(errno));
 		return -1;

q931.c

@@ -1929,10 +1929,10 @@ static FUNC_RECV(receive_generic_digits)
 	}
 	if (len == 3)	/* No number information */
 		return 0;
+	value = 0;
 	switch(type) {
 	/* Integer value handling */
 	case 4:		/* Info Digits */
-		value = 0;
 		for(idx = 3; idx < len; ++idx) {
 			switch(encoding) {
 			case 0:		/* BCD even */