mtp: Make the mtp_link point to a specific type of link

We might want to be able to change the type of a link at
runtime. Decouple the link and the actual type of the link.

10 files changed, 132 insertions, 70 deletions

diff --git a/include/bsc_data.h b/include/bsc_data.h
index c09d922..83061e2 100644
--- a/include/bsc_data.h
+++ b/include/bsc_data.h
@@ -46,7 +46,7 @@ struct mtp_udp_data {
 
 struct mtp_udp_link {
 	/* subclass */
-	struct mtp_link base;
+	struct mtp_link *base;
 
 	/* UDP specific stuff */
 	struct bsc_data *bsc;
diff --git a/include/mtp_data.h b/include/mtp_data.h
index eed113f..48a2b10 100644
--- a/include/mtp_data.h
+++ b/include/mtp_data.h
@@ -37,6 +37,12 @@ struct ss7_application;
 #define MTP_T2		30, 0
 #define START_DELAY	 8, 0
 
+enum ss7_link_type {
+	SS7_LTYPE_NONE,
+	SS7_LTYPE_UDP,
+	SS7_LTYPE_M2UA,
+};
+
 /**
  * The state of the mtp_link in terms of layer3 and upwards
  */
@@ -120,6 +126,10 @@ struct mtp_link {
 	int (*shutdown)(struct mtp_link *);
 	int (*reset)(struct mtp_link *data);
 	int (*clear_queue)(struct mtp_link *data);
+
+	/* private data */
+	enum ss7_link_type type;
+	void *data;
 };
 
 
@@ -130,7 +140,6 @@ int mtp_link_set_submit_sccp_data(struct mtp_link_set *link, int sls, const uint
 int mtp_link_set_submit_isup_data(struct mtp_link_set *link, int sls, const uint8_t *data, unsigned int length);
 
 void mtp_link_set_init_slc(struct mtp_link_set *set);
-int mtp_link_set_add_link(struct mtp_link_set *set, struct mtp_link *link);
 
 void mtp_link_block(struct mtp_link *link);
 void mtp_link_unblock(struct mtp_link *link);
@@ -147,7 +156,6 @@ int mtp_link_set_send(struct mtp_link_set *set, struct msgb *msg);
 void mtp_link_down(struct mtp_link *data);
 void mtp_link_up(struct mtp_link *data);
 
-int mtp_link_init(struct mtp_link *link);
 void mtp_link_start_link_test(struct mtp_link *link);
 void mtp_link_stop_link_test(struct mtp_link *link);
 int mtp_link_slta(struct mtp_link *link, uint16_t l3_len, struct mtp_level_3_mng *mng);
@@ -161,4 +169,7 @@ struct msgb *mtp_msg_alloc(struct mtp_link_set *link);
 struct mtp_link_set *mtp_link_set_alloc(struct bsc_data *bsc);
 struct mtp_link_set *mtp_link_set_num(struct bsc_data *bsc, int num);
 
+struct mtp_link *mtp_link_alloc(struct mtp_link_set *set);
+struct mtp_link *mtp_link_num(struct mtp_link_set *set, int num);
+
 #endif
diff --git a/include/sctp_m2ua.h b/include/sctp_m2ua.h
index 1c001cd..9f4d5c7 100644
--- a/include/sctp_m2ua.h
+++ b/include/sctp_m2ua.h
@@ -42,7 +42,7 @@ struct sctp_m2ua_transport {
 };
 
 struct mtp_m2ua_link {
-	struct mtp_link base;
+	struct mtp_link *base;
 
 	int link_index;
 	struct llist_head entry;
diff --git a/src/link_udp.c b/src/link_udp.c
index bcf8ec6..b7d9200 100644
--- a/src/link_udp.c
+++ b/src/link_udp.c
@@ -61,7 +61,7 @@ static int udp_write_cb(struct bsc_fd *fd, struct msgb *msg)
 	}
 
 	LOGP(DINP, LOGL_DEBUG, "Sending MSU: %s\n", hexdump(msg->data, msg->len));
-	mtp_handle_pcap(&link->base, NET_OUT, msg->l2h, msgb_l2len(msg));
+	mtp_handle_pcap(link->base, NET_OUT, msg->l2h, msgb_l2len(msg));
 
 	/* the assumption is we have connected the socket to the remote */
 	rc = sendto(fd->fd, msg->data, msg->len, 0,
@@ -77,6 +77,7 @@ static int udp_write_cb(struct bsc_fd *fd, struct msgb *msg)
 static int udp_read_cb(struct bsc_fd *fd)
 {
 	struct mtp_udp_data *data;
+	struct mtp_udp_link *ulnk;
 	struct mtp_link *link;
 	struct udp_data_hdr *hdr;
 	struct msgb *msg;
@@ -99,14 +100,15 @@ static int udp_read_cb(struct bsc_fd *fd)
 	}
 
 	hdr = (struct udp_data_hdr *) msgb_put(msg, sizeof(*hdr));
-	link = (struct mtp_link *) find_link(data, ntohs(hdr->data_link_index));
+	ulnk = find_link(data, ntohs(hdr->data_link_index));
 
-	if (!link) {
+	if (!ulnk) {
 		LOGP(DINP, LOGL_ERROR, "No link registered for %d\n",
 		     ntohs(hdr->data_link_index));
 		goto exit;
 	}
 
+	link = ulnk->base;
 	if (link->blocked) {
 		LOGP(DINP, LOGL_ERROR, "The link is blocked.\n");
 		rc = 0;
@@ -181,7 +183,7 @@ static int udp_link_reset(struct mtp_link *link)
 {
 	struct mtp_udp_link *ulnk;
 
-	ulnk = (struct mtp_udp_link *) link;
+	ulnk = (struct mtp_udp_link *) link->data;
 
 	snmp_mtp_deactivate(ulnk->session, ulnk->link_index);
 	return 0;
@@ -197,7 +199,7 @@ static int udp_link_write(struct mtp_link *link, struct msgb *msg)
 	struct mtp_udp_link *ulnk;
 	struct udp_data_hdr *hdr;
 
-	ulnk = (struct mtp_udp_link *) link;
+	ulnk = (struct mtp_udp_link *) link->data;
 
 	hdr = (struct udp_data_hdr *) msgb_push(msg, sizeof(*hdr));
 	hdr->format_type = UDP_FORMAT_SIMPLE_UDP;
@@ -233,12 +235,12 @@ int link_udp_init(struct mtp_udp_link *link, char *remote, int port)
 	link->session->data = link;
 
 	/* function table */
-	link->base.shutdown = udp_link_shutdown;
-	link->base.clear_queue = udp_link_dummy;
+	link->base->shutdown = udp_link_shutdown;
+	link->base->clear_queue = udp_link_dummy;
 
-	link->base.reset = udp_link_reset;
-	link->base.start = udp_link_start;
-	link->base.write = udp_link_write;
+	link->base->reset = udp_link_reset;
+	link->base->start = udp_link_start;
+	link->base->write = udp_link_write;
 
 	/* prepare the remote */
 	memset(&link->remote, 0, sizeof(link->remote));
@@ -317,7 +319,7 @@ void snmp_mtp_callback(struct snmp_mtp_session *session,
 	if (!ulink)
 		return LOGP(DINP, LOGL_ERROR, "Failed to find link_id %d\n", link_id);
 
-	link = &ulink->base;
+	link = ulink->base;
 
 	if (res == SNMP_STATUS_TIMEOUT && !link->blocked) {
 		LOGP(DINP, LOGL_ERROR, "Failed to restart link: %s/%d\n",
@@ -338,7 +340,7 @@ void snmp_mtp_callback(struct snmp_mtp_session *session,
 		 */
 		if (!link->blocked) {
 			link->link_activate.cb = do_start;
-			link->link_activate.data = link;
+			link->link_activate.data = ulink;
 			bsc_schedule_timer(&link->link_activate, ulink->reset_timeout, 0);
 			LOGP(DINP, LOGL_NOTICE,
 			     "Will bring up link %s/%d in %d seconds.\n",
diff --git a/src/links.c b/src/links.c
index ccc8bfb..fae1dea 100644
--- a/src/links.c
+++ b/src/links.c
@@ -90,6 +90,7 @@ struct mtp_link_set *link_init(struct bsc_data *bsc)
 {
 	int i;
 	struct mtp_udp_link *lnk;
+	struct mtp_link *blnk;
 	struct mtp_link_set *set;
 
 	set = mtp_link_set_alloc(bsc);
@@ -121,14 +122,15 @@ struct mtp_link_set *link_init(struct bsc_data *bsc)
 
 
 	for (i = 1; i <= bsc->udp_nr_links; ++i) {
-		lnk = talloc_zero(set, struct mtp_udp_link);
-		lnk->base.pcap_fd = -1;
+		blnk = mtp_link_alloc(set);
+		lnk = talloc_zero(blnk, struct mtp_udp_link);
+		lnk->base = blnk;
+		lnk->base->data = lnk;
+		lnk->base->type = SS7_LTYPE_UDP;
 		lnk->bsc = bsc;
 		lnk->data = &bsc->udp_data;
 		lnk->link_index = i;
 		lnk->reset_timeout = bsc->udp_reset_timeout;
-		mtp_link_set_add_link(set, (struct mtp_link *) lnk);
-
 
 		/* now connect to the transport */
 		if (link_udp_init(lnk, bsc->udp_ip, bsc->udp_port) != 0)
diff --git a/src/main_stp.c b/src/main_stp.c
index a4694b9..ba204a7 100644
--- a/src/main_stp.c
+++ b/src/main_stp.c
@@ -275,8 +275,6 @@ int main(int argc, char **argv)
 	m2ua_set->pass_all_isup = bsc->isup_pass;
 
 	lnk = mtp_m2ua_link_create(bsc->m2ua_trans, m2ua_set);
-	lnk->base.pcap_fd = -1;
-	mtp_link_set_add_link(m2ua_set, (struct mtp_link *) lnk);
 
 	ss7_application_setup(app, APP_STP,
 			      SS7_SET_LINKSET, 0,
diff --git a/src/mtp_layer3.c b/src/mtp_layer3.c
index 83c8d63..0ef416c 100644
--- a/src/mtp_layer3.c
+++ b/src/mtp_layer3.c
@@ -582,18 +582,6 @@ void mtp_link_set_init_slc(struct mtp_link_set *set)
 	}
 }
 
-int mtp_link_set_add_link(struct mtp_link_set *set, struct mtp_link *lnk)
-{
-	lnk->set = set;
-	lnk->link_no = set->nr_links++;
-	if (mtp_link_init(lnk) != 0)
-		return -1;
-
-	llist_add_tail(&lnk->entry, &set->links);
-	mtp_link_set_init_slc(set);
-	return 0;
-}
-
 struct mtp_link_set *mtp_link_set_alloc(struct bsc_data *bsc)
 {
 	struct mtp_link_set *link;
diff --git a/src/mtp_link.c b/src/mtp_link.c
index 009547c..142d78a 100644
--- a/src/mtp_link.c
+++ b/src/mtp_link.c
@@ -24,6 +24,8 @@
 #include <cellmgr_debug.h>
 #include <counter.h>
 
+#include <osmocore/talloc.h>
+
 #include <string.h>
 
 static struct msgb *mtp_create_sltm(struct mtp_link *link)
@@ -114,22 +116,6 @@ static void mtp_sltm_t2_timeout(void *_link)
 		bsc_schedule_timer(&link->t2_timer, MTP_T2);
 }
 
-int mtp_link_init(struct mtp_link *link)
-{
-	link->ctrg = rate_ctr_group_alloc(link,
-					  mtp_link_rate_ctr_desc(), link->link_no);
-	if (!link->ctrg) {
-		LOGP(DINP, LOGL_ERROR, "Failed to allocate rate_ctr.\n");
-		return -1;
-	}
-
-	link->t1_timer.data = link;
-	link->t1_timer.cb = mtp_sltm_t1_timeout;
-	link->t2_timer.data = link;
-	link->t2_timer.cb = mtp_sltm_t2_timeout;
-	return 0;
-}
-
 void mtp_link_stop_link_test(struct mtp_link *link)
 {
 	bsc_del_timer(&link->t1_timer);
@@ -196,3 +182,70 @@ void mtp_link_unblock(struct mtp_link *link)
 	link->blocked = 0;
 	link->reset(link);
 }
+
+static int dummy_arg1(struct mtp_link *link)
+{
+	LOGP(DINP, LOGL_ERROR, "The link %d of linkset %d/%s is not typed.\n",
+	     link->link_no, link->set->nr, link->set->name);
+	return 0;
+}
+
+static int dummy_arg2(struct mtp_link *link, struct msgb *msg)
+{
+	LOGP(DINP, LOGL_ERROR, "The link %d of linkset %d/%s is not typed.\n",
+	     link->link_no, link->set->nr, link->set->name);
+	msgb_free(msg);
+	return 0;
+}
+
+struct mtp_link *mtp_link_alloc(struct mtp_link_set *set)
+{
+	struct mtp_link *link;
+
+	link = talloc_zero(set, struct mtp_link);
+	if (!link) {
+		LOGP(DINP, LOGL_ERROR, "Failed to allocate the link.\n");
+		return NULL;
+	}
+
+	link->link_no = set->nr_links++;
+	link->ctrg = rate_ctr_group_alloc(link,
+					  mtp_link_rate_ctr_desc(), link->link_no);
+	if (!link->ctrg) {
+		LOGP(DINP, LOGL_ERROR, "Failed to allocate rate_ctr.\n");
+		talloc_free(link);
+		return NULL;
+	}
+
+	/* make sure a unconfigured link does not crash */
+	link->start = dummy_arg1;
+	link->write = dummy_arg2;
+	link->shutdown = dummy_arg1;
+	link->reset = dummy_arg1;
+	link->clear_queue = dummy_arg1;
+
+	link->pcap_fd = -1;
+
+	link->t1_timer.data = link;
+	link->t1_timer.cb = mtp_sltm_t1_timeout;
+	link->t2_timer.data = link;
+	link->t2_timer.cb = mtp_sltm_t2_timeout;
+
+	link->set = set;
+
+	llist_add_tail(&link->entry, &set->links);
+	mtp_link_set_init_slc(set);
+
+	return link;
+}
+
+struct mtp_link *mtp_link_num(struct mtp_link_set *set, int num)
+{
+	struct mtp_link *link;
+
+	llist_for_each_entry(link, &set->links, entry)
+		if (link->link_no == num)
+			return link;
+
+	return NULL;
+}
diff --git a/src/sctp_m2ua.c b/src/sctp_m2ua.c
index 284bf8a..155043d 100644
--- a/src/sctp_m2ua.c
+++ b/src/sctp_m2ua.c
@@ -61,7 +61,7 @@ static void m2ua_conn_destroy(struct sctp_m2ua_conn *conn)
 	/* TODO: hardcoded link index */
 	link = find_m2ua_link(conn->trans, 0);
 	if (link && conn->asp_up && conn->asp_active && conn->established)
-		link_down(&link->base);
+		link_down(link->base);
 	talloc_free(conn);
 
 	#warning "Notify any other AS(P) for failover scenario"
@@ -288,7 +288,7 @@ static int m2ua_handle_est_req(struct mtp_m2ua_link *link,
 
 	conn->established = 1;
 	LOGP(DINP, LOGL_NOTICE, "M2UA/Link is established.\n");
-	mtp_link_up(&link->base);
+	mtp_link_up(link->base);
 	m2ua_msg_free(conf);
 	return 0;
 }
@@ -314,7 +314,7 @@ static int m2ua_handle_rel_req(struct mtp_m2ua_link *link,
 
 	conn->established = 0;
 	LOGP(DINP, LOGL_NOTICE, "M2UA/Link is released.\n");
-	link_down(&link->base);
+	link_down(link->base);
 	m2ua_msg_free(conf);
 	return 0;
 }
@@ -348,7 +348,7 @@ static int m2ua_handle_data(struct mtp_m2ua_link *_link,
 	msg->l2h = msgb_put(msg, data->len);
 	memcpy(msg->l2h, data->dat, data->len);
 
-	link = &_link->base;
+	link = _link->base;
 	if (!link->blocked) {
 		mtp_handle_pcap(link, NET_IN, msg->l2h, msgb_l2len(msg));
 		mtp_link_set_data(link, msg);
@@ -496,7 +496,7 @@ static int sctp_m2ua_write(struct mtp_link *link, struct msgb *msg)
 	struct m2ua_msg *m2ua;
 	uint32_t interface;
 
-	mlink = (struct mtp_m2ua_link *) link;
+	mlink = (struct mtp_m2ua_link *) link->data;
 	trans = mlink->transport;
 
 	if (llist_empty(&trans->conns))
@@ -616,7 +616,7 @@ static int sctp_m2ua_dummy(struct mtp_link *link)
 
 static int sctp_m2ua_start(struct mtp_link *_link)
 {
-	struct mtp_m2ua_link *link = (struct mtp_m2ua_link *) _link;
+	struct mtp_m2ua_link *link = (struct mtp_m2ua_link *) _link->data;
 
 	link->transport->started = 1;
 	return 0;
@@ -625,7 +625,7 @@ static int sctp_m2ua_start(struct mtp_link *_link)
 static int sctp_m2ua_reset(struct mtp_link *_link)
 {
 	struct sctp_m2ua_conn *conn, *tmp;
-	struct mtp_m2ua_link *link = (struct mtp_m2ua_link *) _link;
+	struct mtp_m2ua_link *link = (struct mtp_m2ua_link *) _link->data;
 
 	/* TODO: only connection that use the current link index! */
 	llist_for_each_entry_safe(conn, tmp, &link->transport->conns, entry)
@@ -694,22 +694,35 @@ struct sctp_m2ua_transport *sctp_m2ua_transp_create(const char *ip, int port)
 struct mtp_m2ua_link *mtp_m2ua_link_create(struct sctp_m2ua_transport *trans,
 					   struct mtp_link_set *set)
 {
+	struct mtp_link *blnk;
 	struct mtp_m2ua_link *lnk;
 
-	lnk = talloc_zero(set, struct mtp_m2ua_link);
+	blnk = mtp_link_alloc(set);
+	if (!blnk) {
+		LOGP(DINP, LOGL_ERROR, "Failed to allocate.\n");
+		return NULL;
+	}
+
+	lnk = talloc_zero(blnk, struct mtp_m2ua_link);
 	if (!lnk) {
 		LOGP(DINP, LOGL_ERROR, "Failed to allocate.\n");
+		talloc_free(blnk);
 		return NULL;
 	}
 
+	/* make sure we can resolve it both ways */
+	lnk->base = blnk;
+	blnk->data = lnk;
+	blnk->type = SS7_LTYPE_M2UA;
+
 	/* remember we have a link here */
 	llist_add(&lnk->entry, &trans->links);
 
-	lnk->base.shutdown = sctp_m2ua_reset;
-	lnk->base.clear_queue = sctp_m2ua_dummy;
-	lnk->base.reset = sctp_m2ua_reset;
-	lnk->base.start = sctp_m2ua_start;
-	lnk->base.write = sctp_m2ua_write;
+	lnk->base->shutdown = sctp_m2ua_reset;
+	lnk->base->clear_queue = sctp_m2ua_dummy;
+	lnk->base->reset = sctp_m2ua_reset;
+	lnk->base->start = sctp_m2ua_start;
+	lnk->base->write = sctp_m2ua_write;
 
 	lnk->transport = trans;
 	return lnk;
diff --git a/src/vty_interface.c b/src/vty_interface.c
index 0c1cb3d..06df291 100644
--- a/src/vty_interface.c
+++ b/src/vty_interface.c
@@ -494,18 +494,13 @@ DEFUN(pcap_set_stop, pcap_set_stop_cmd,
 
 #define FIND_LINK(vty, set_no, nr) ({						\
 	struct mtp_link_set *set = NULL;					\
-	struct mtp_link *link = NULL, *tmp;					\
+	struct mtp_link *link = NULL;						\
 	set = mtp_link_set_num(bsc, set_no);					\
 	if (!set) {								\
 		vty_out(vty, "Unknown Linkset nr %d.%s", set_no, VTY_NEWLINE);	\
 		return CMD_WARNING;						\
 	}									\
-	llist_for_each_entry(tmp, &set->links, entry) {				\
-		if (tmp->link_no == nr) {					\
-			link = tmp;						\
-			break;							\
-		}								\
-	}									\
+	link = mtp_link_num(set, nr);						\
 	if (!link) {								\
 		vty_out(vty, "Can not find link %d.%s", nr, VTY_NEWLINE);	\
 		return CMD_WARNING;						\