Fix output of route destination in 'show ss7 instance <0-15> route'

We were printing the mask of the route, but not the point code itself.

Best would probably be to print both?

Closes: OS#3835
Change-Id: Ifa4fdbad953d40f222beb470a082eed8c20991ef

5 files changed, 53 insertions, 1 deletions

diff --git a/include/osmocom/sigtran/osmo_ss7.h b/include/osmocom/sigtran/osmo_ss7.h
index a97e236..f448ce7 100644
--- a/include/osmocom/sigtran/osmo_ss7.h
+++ b/include/osmocom/sigtran/osmo_ss7.h
@@ -238,6 +238,7 @@ struct osmo_ss7_route *
 osmo_ss7_route_create(struct osmo_ss7_route_table *rtbl, uint32_t dpc,
 			uint32_t mask, const char *linkset_name);
 void osmo_ss7_route_destroy(struct osmo_ss7_route *rt);
+const char *osmo_ss7_route_print(const struct osmo_ss7_route *rt);
 const char *osmo_ss7_route_name(struct osmo_ss7_route *rt, bool list_asps);
 
 
diff --git a/src/osmo_ss7.c b/src/osmo_ss7.c
index f8633b6..e8a6918 100644
--- a/src/osmo_ss7.c
+++ b/src/osmo_ss7.c
@@ -838,6 +838,48 @@ void osmo_ss7_route_destroy(struct osmo_ss7_route *rt)
 	talloc_free(rt);
 }
 
+/* count number of consecutive leading (MSB) bits that are '1' */
+static unsigned int count_leading_one_bits(uint32_t inp, unsigned int nbits)
+{
+	unsigned int i;
+
+	for (i = 0; i < nbits; i++) {
+		if (!(inp & (1 << (nbits-1-i))))
+			return i;
+	}
+	return i;
+}
+
+/* determine the mask length in number of bits; negative if non-consecutive mask */
+static int u32_masklen(uint32_t mask, unsigned int nbits)
+{
+	unsigned int i;
+	unsigned int leading_one_bits = count_leading_one_bits(mask, nbits);
+
+	/* are there any bits set after the initial bits? */
+	for (i = leading_one_bits; i < nbits; i++) {
+		if (mask & (1 << (nbits-1-i)))
+			return -1; /* not a simple prefix mask */
+	}
+	return leading_one_bits;
+}
+
+const char *osmo_ss7_route_print(const struct osmo_ss7_route *rt)
+{
+	const struct osmo_ss7_instance *inst = rt->rtable->inst;
+	unsigned int pc_width = osmo_ss7_pc_width(&inst->cfg.pc_fmt);
+	static char buf[64];
+	int rc = u32_masklen(rt->cfg.mask, pc_width);
+
+	if (rc < 0)
+		snprintf(buf, sizeof(buf), "%s/%s", osmo_ss7_pointcode_print(inst, rt->cfg.pc),
+			 osmo_ss7_pointcode_print2(inst, rt->cfg.mask));
+	else
+		snprintf(buf, sizeof(buf), "%s/%u", osmo_ss7_pointcode_print(inst, rt->cfg.pc), rc);
+	return buf;
+}
+
+
 /***********************************************************************
  * SS7 Application Server
  ***********************************************************************/
diff --git a/src/osmo_ss7_vty.c b/src/osmo_ss7_vty.c
index 950eb08..cc53b05 100644
--- a/src/osmo_ss7_vty.c
+++ b/src/osmo_ss7_vty.c
@@ -384,7 +384,7 @@ static void vty_dump_rtable(struct vty *vty, struct osmo_ss7_route_table *rtbl)
 
 	llist_for_each_entry(rt, &rtbl->routes, list) {
 		vty_out(vty, "%-22s %c %c %u %-19s %-7s %-7s %-7s%s",
-			osmo_ss7_pointcode_print(rtbl->inst, rt->cfg.mask),
+			osmo_ss7_route_print(rt),
 			' ', ' ', rt->cfg.priority, rt->cfg.linkset_name, "?", "?", "?", VTY_NEWLINE);
 	}
 }
diff --git a/tests/ss7/ss7_test.c b/tests/ss7/ss7_test.c
index 0c0cf25..a3f47b6 100644
--- a/tests/ss7/ss7_test.c
+++ b/tests/ss7/ss7_test.c
@@ -162,12 +162,14 @@ static void test_route(void)
 	/* route with full mask */
 	OSMO_ASSERT(osmo_ss7_route_find_dpc(rtbl, 12) == NULL);
 	rt = osmo_ss7_route_create(rtbl, 12, 0xffff, "a");
+	printf("route with full mask: %s\n", osmo_ss7_route_print(rt));
 	OSMO_ASSERT(rt);
 	OSMO_ASSERT(osmo_ss7_route_find_dpc(rtbl, 12) == rt);
 	osmo_ss7_route_destroy(rt);
 
 	/* route with partial mask */
 	rt = osmo_ss7_route_create(rtbl, 8, 0xfff8, "a");
+	printf("route with partial mask: %s\n", osmo_ss7_route_print(rt));
 	OSMO_ASSERT(osmo_ss7_route_find_dpc(rtbl, 8) == rt);
 	OSMO_ASSERT(osmo_ss7_route_find_dpc(rtbl, 9) == rt);
 	OSMO_ASSERT(osmo_ss7_route_find_dpc(rtbl, 12) == rt);
@@ -189,6 +191,10 @@ static void test_route(void)
 	osmo_ss7_route_destroy(rt12);
 	osmo_ss7_route_destroy(rt);
 
+	rt = osmo_ss7_route_create(rtbl, 8, 0xfff9, "a");
+	printf("route with non-consecutive mask: %s\n", osmo_ss7_route_print(rt));
+	osmo_ss7_route_destroy(rt);
+
 	osmo_ss7_linkset_destroy(lset_a);
 	osmo_ss7_linkset_destroy(lset_b);
 }
diff --git a/tests/ss7/ss7_test.ok b/tests/ss7/ss7_test.ok
index 8aea63d..1f8c0d8 100644
--- a/tests/ss7/ss7_test.ok
+++ b/tests/ss7/ss7_test.ok
@@ -24,4 +24,7 @@ mask /16 => 16776960 (0xffff00) 255-255-0
 mask /24 => 16777215 (0xffffff) 255-255-255
 Testing SS7 user
 Testing SS7 routing
+route with full mask: 0.1.4/14
+route with partial mask: 0.1.0/11
+route with non-consecutive mask: 0.1.0/7.255.1
 Testing SS7 linkset/link