major updates in e1_input callback ops and IPA infrastructures

This patch is a major update of the callback infrastructure, now
the e1input_ops looks like the following:

struct e1inp_sign_link *        (*sign_link_up)(void *unit_info, struct e1inp_line *line, enum e1inp_sign_type type);

void    (*sign_link_down)(struct e1inp_line *line);

int     (*sign_link)(struct msgb *msg, struct e1inp_sign_link *link);

The sign_link_up and sign_link_down will be used by the A-bis over IP
input drivers.

The sign_link_up callback is used if we receive a ID_RESP message, in
that case, we have to set up the sign link for the corresponding new
OML/RSL signal link. The pointer to unit_info provides a data structure
that contains the BTS device details if we run as BSC, and the requested
device information from the BSC if we run as BTS. The sign_link_up
callback must return the new sign_link created.

The sign_link_down callback is invoked if the line does down, which
means that the counterpart has closed the socket.

The sign_link callback is used to handle all RSL/OML messages.

I have also added the following callback to the e1inp_driver:

+       void (*close)(struct e1inp_ts *ts);

Which is invoked if you call e1inp_sign_link_destroy(). This callback
is used to close the socket that is linked to that timeslot. This is
useful for A-bis over IP drivers since sockets are closed if the
OML/RSL signalling link is destroyed.

As you can notice, I have also added all the ID_RESP parsing into
libosmo-abis for both ipaccess and hsl drivers.

This patch also contains a rework of the ipa_client_link whose
integration with the e1_input infrastructure was broken (the
transmission path was broken).

This patch also contains more develop examples that act as BSC
and BTS for the ipaccess driver.

Sorry, I know it would be better to split all these changes into
logical pieces but many of them are tightly related.

This is under heavy development stage, it's anyway hard to track
changes until this becomes more stable.

2 files changed, 218 insertions, 45 deletions

diff --git a/tests/e1inp_ipa_bsc_test.c b/tests/e1inp_ipa_bsc_test.c
index 64623b2..bac9926 100644
--- a/tests/e1inp_ipa_bsc_test.c
+++ b/tests/e1inp_ipa_bsc_test.c
@@ -6,25 +6,42 @@
 #include <osmocom/core/logging.h>
 
 static void *tall_test;
+static struct e1inp_sign_link *oml_sign_link, *rsl_sign_link;
 
-static int sign_link_up(struct msgb *msg, struct e1inp_line *line,
-			enum e1inp_sign_type type)
+static struct e1inp_sign_link *
+sign_link_up(void *dev, struct e1inp_line *line, enum e1inp_sign_type type)
 {
-	printf("ID_RESP received, create sign link.\n");
-	return 0;
+	struct e1inp_sign_link *sign_link = NULL;
+
+	switch(type) {
+	case E1INP_SIGN_OML:
+		e1inp_ts_config_sign(&line->ts[E1INP_SIGN_OML - 1], line);
+		sign_link = oml_sign_link =
+			e1inp_sign_link_create(&line->ts[E1INP_SIGN_OML - 1],
+					       E1INP_SIGN_OML, NULL, 255, 0);
+		break;
+	case E1INP_SIGN_RSL:
+		e1inp_ts_config_sign(&line->ts[E1INP_SIGN_RSL - 1], line);
+		sign_link = rsl_sign_link =
+			e1inp_sign_link_create(&line->ts[E1INP_SIGN_RSL - 1],
+					       E1INP_SIGN_OML, NULL, 0, 0);
+		break;
+	default:
+		break;
+	}
+	return sign_link;
 }
 
-static int sign_link(struct msgb *msg, struct e1inp_line *line,
-		     struct e1inp_sign_link *link)
+static void sign_link_down(struct e1inp_line *line)
 {
-	printf("OML/RSL data received\n");
-	return 0;
+	printf("link got down.\n");
+	e1inp_sign_link_destroy(oml_sign_link);
+	e1inp_sign_link_destroy(rsl_sign_link);
 }
 
-static int error(struct msgb *msg, struct e1inp_line *line,
-		 enum e1inp_sign_type type, int error)
+static int sign_link(struct msgb *msg, struct e1inp_sign_link *link)
 {
-	printf("error, malformed message\n");
+	printf("OML/RSL data received\n");
 	return 0;
 }
 
@@ -58,8 +75,8 @@ int main(void)
 		.addr		= "0.0.0.0",
 		.role		= E1INP_LINE_R_BSC,
 		.sign_link_up	= sign_link_up,
+		.sign_link_down	= sign_link_down,
 		.sign_link	= sign_link,
-		.error		= error,
 	};
 
 #define LINENR 0
diff --git a/tests/e1inp_ipa_bts_test.c b/tests/e1inp_ipa_bts_test.c
index 9c6bd4c..643e898 100644
--- a/tests/e1inp_ipa_bts_test.c
+++ b/tests/e1inp_ipa_bts_test.c
@@ -1,32 +1,14 @@
 #include <stdio.h>
 #include <talloc.h>
+#include <string.h>
 #include <osmocom/abis/abis.h>
 #include <osmocom/abis/e1_input.h>
 #include <osmocom/core/logging.h>
 #include <osmocom/core/application.h>
+#include <osmocom/abis/ipaccess.h>
 
 static void *tall_test;
-
-static int sign_link_up(struct msgb *msg, struct e1inp_line *line,
-			enum e1inp_sign_type type)
-{
-	printf("ID_RESP received, create sign link.\n");
-	return 0;
-}
-
-static int sign_link(struct msgb *msg, struct e1inp_line *line,
-			struct e1inp_sign_link *link)
-{
-	printf("OML/RSL data received\n");
-	return 0;
-}
-
-static int error(struct msgb *msg, struct e1inp_line *line,
-		 enum e1inp_sign_type type, int error)
-{
-	printf("error, malformed message\n");
-	return 0;
-}
+static struct e1inp_sign_link *oml_sign_link, *rsl_sign_link;
 
 #define DBTSTEST OSMO_LOG_SS_APPS
 
@@ -45,6 +27,191 @@ const struct log_info bts_test_log_info = {
 	.num_cat = ARRAY_SIZE(bts_test_cat),
 };
 
+struct dummy_bts {
+	uint16_t	bts_id;
+	uint16_t	site_id;
+	uint16_t	trx_id;
+	uint8_t		mac_addr[6];
+} dummy_bts = {
+	.site_id	= 0,
+	.bts_id		= 0,
+	.trx_id		= 0,
+	.mac_addr	= {0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
+};
+
+char *software_version = "0.1";
+
+static struct msgb *abis_msgb_alloc(int headroom)
+{
+	struct msgb *nmsg;
+
+	headroom += sizeof(struct ipaccess_head);
+
+	nmsg = msgb_alloc_headroom(1200 + headroom, headroom, "dummy BTS");
+	if (!nmsg)
+		return NULL;
+	return nmsg;
+}
+
+static void abis_push_ipa(struct msgb *msg, uint8_t proto)
+{
+	struct ipaccess_head *nhh;
+
+	msg->l2h = msg->data;
+	nhh = (struct ipaccess_head *) msgb_push(msg, sizeof(*nhh));
+	nhh->proto = proto;
+	nhh->len = htons(msgb_l2len(msg));
+}
+
+/* XXX: we have to do this in input/ipaccess.c, moreover we have to put this
+ * information in some data structure that we'll pass to sign_link_up. */
+static struct msgb *ipa_bts_id_resp(uint8_t *data, int len)
+{
+	struct msgb *nmsg;
+	char str[64];
+	uint8_t *tag;
+
+	nmsg = abis_msgb_alloc(0);
+	if (!nmsg)
+		return NULL;
+
+	*msgb_put(nmsg, 1) = IPAC_MSGT_ID_RESP;
+	while (len) {
+		if (len < 2) {
+			LOGP(DBTSTEST, LOGL_NOTICE,
+				"Short read of ipaccess tag\n");
+			msgb_free(nmsg);
+			return NULL;
+		}
+		switch (data[1]) {
+		case IPAC_IDTAG_UNIT:
+			sprintf(str, "%u/%u/%u",
+				dummy_bts.site_id,
+				dummy_bts.bts_id,
+				dummy_bts.trx_id);
+			break;
+		case IPAC_IDTAG_MACADDR:
+			sprintf(str, "%02x:%02x:%02x:%02x:%02x:%02x",
+				dummy_bts.mac_addr[0], dummy_bts.mac_addr[1],
+				dummy_bts.mac_addr[2], dummy_bts.mac_addr[3],
+				dummy_bts.mac_addr[4], dummy_bts.mac_addr[5]);
+			break;
+		case IPAC_IDTAG_LOCATION1:
+			strcpy(str, "osmoBTS");
+			break;
+		case IPAC_IDTAG_LOCATION2:
+			strcpy(str, "osmoBTS");
+			break;
+		case IPAC_IDTAG_EQUIPVERS:
+		case IPAC_IDTAG_SWVERSION:
+			strcpy(str, software_version);
+			break;
+		case IPAC_IDTAG_UNITNAME:
+			sprintf(str, "osmoBTS-%02x-%02x-%02x-%02x-%02x-%02x",
+				dummy_bts.mac_addr[0], dummy_bts.mac_addr[1],
+				dummy_bts.mac_addr[2], dummy_bts.mac_addr[3],
+				dummy_bts.mac_addr[4], dummy_bts.mac_addr[5]);
+			break;
+		case IPAC_IDTAG_SERNR:
+			strcpy(str, "");
+			break;
+		default:
+			LOGP(DBTSTEST, LOGL_NOTICE,
+				"Unknown ipaccess tag 0x%02x\n", *data);
+			msgb_free(nmsg);
+			return NULL;
+		}
+		LOGP(DBTSTEST, LOGL_INFO, " tag %d: %s\n", data[1], str);
+		tag = msgb_put(nmsg, 3 + strlen(str) + 1);
+		tag[0] = 0x00;
+		tag[1] = 1 + strlen(str) + 1;
+		tag[2] = data[1];
+		memcpy(tag + 3, str, strlen(str) + 1);
+		data += 2;
+		len -= 2;
+	}
+	abis_push_ipa(nmsg, IPAC_PROTO_IPACCESS);
+	return nmsg;
+}
+
+static struct msgb *ipa_bts_id_ack(void)
+{
+	struct msgb *nmsg2;
+
+	nmsg2 = abis_msgb_alloc(0);
+	if (!nmsg2)
+		return NULL;
+
+	*msgb_put(nmsg2, 1) = IPAC_MSGT_ID_ACK;
+	abis_push_ipa(nmsg2, IPAC_PROTO_IPACCESS);
+
+	return nmsg2;
+}
+
+static struct e1inp_sign_link *
+sign_link_up(void *unit, struct e1inp_line *line, enum e1inp_sign_type type)
+{
+	struct msgb *msg = unit;
+	struct msgb *rmsg;
+	uint8_t *data = msgb_l2(msg);
+	int len = msgb_l2len(msg);
+	struct e1inp_sign_link *sign_link = NULL;
+	void *dst = NULL;
+
+	switch(type) {
+	case E1INP_SIGN_OML:
+		printf("ID_RESP for OML received.\n");
+
+		e1inp_ts_config_sign(&line->ts[E1INP_SIGN_OML - 1], line);
+		sign_link = oml_sign_link =
+			e1inp_sign_link_create(&line->ts[E1INP_SIGN_OML - 1],
+						E1INP_SIGN_OML, NULL, 255, 0);
+		if (!oml_sign_link)
+			printf("cannot create OML sign link\n");
+
+		dst = oml_sign_link;
+		break;
+	case E1INP_SIGN_RSL:
+		printf("ID_RESP for RSL received.\n");
+
+		e1inp_ts_config_sign(&line->ts[E1INP_SIGN_RSL - 1], line);
+
+		sign_link = rsl_sign_link =
+			e1inp_sign_link_create(&line->ts[E1INP_SIGN_RSL - 1],
+						E1INP_SIGN_RSL, NULL, 0, 0);
+		if (!rsl_sign_link)
+			printf("cannot create RSL sign link\n");
+
+		dst = rsl_sign_link;
+		break;
+	default:
+		return NULL;
+	}
+
+	/* send ID_RESP. */
+	rmsg = ipa_bts_id_resp(data + 1, len - 1);
+	rmsg->dst = dst;
+	abis_sendmsg(rmsg);
+
+	/* send ID_ACK. */
+	rmsg = ipa_bts_id_ack();
+	rmsg->dst = dst;
+	abis_sendmsg(rmsg);
+
+	return sign_link;
+}
+
+static void sign_link_down(struct e1inp_line *line)
+{
+	printf("closing sign link.\n");
+}
+
+static int sign_link(struct msgb *msg, struct e1inp_sign_link *link)
+{
+	printf("OML/RSL data received\n");
+	return 0;
+}
+
 int main(void)
 {
 	struct e1inp_line *line;
@@ -58,8 +225,8 @@ int main(void)
 		.role		= E1INP_LINE_R_BTS,
 		.addr		= "127.0.0.1",
 		.sign_link_up	= sign_link_up,
+		.sign_link_down	= sign_link_down,
 		.sign_link	= sign_link,
-		.error		= error,
 	};
 
 #define LINENR 0
@@ -71,17 +238,6 @@ int main(void)
 	}
 	e1inp_line_bind_ops(line, &ops);
 
-	/*
-	 * Depending if this is a real or virtual E1 lines:
-	 * - real (ISDN): create signal link for OML and RSL before line up.
-	 * - vitual (INET): we create it in signal_link_up(...) callback.
-	 *
-	 * The signal link is created via e1inp_sign_link_create(...)
-	 *
-	 * See e1_reconfig_trx and e1_reconfig_bts in libbsc/e1_config.c,
-	 * it explains how this is done with ISDN.
-	 */
-
 	if (e1inp_line_update(line) < 0) {
 		LOGP(DBTSTEST, LOGL_ERROR, "problem enabling E1 line\n");
 		exit(EXIT_FAILURE);