gtphub: add first bits of GRX ares

For the resolving function, change the function signature to return a
gtphub_peer_port. In consequence, publish two functions concerned with
gtphub_peer_port instances for use in test and gtphub_ext.c.

Add GGSN resolution queue, callback and cache. Simple implementation: if an
SGSN asks for a GGSN, it will first get no answer, and I hope it will ask again
once the GGSN is in the cache.

Within gtphub_ext.c, have a dummy sgsn struct, as the sgsn_ares code currently
depends on it (half the functions pass an sgsn instance pointer around, but the
other half use the global one).

In the unit tests, wrap away the ares initialization so that they can work
without a DNS server around. The netcat test breaks because of this, will
remove it.

Using sgsn_ares, implement the gtphub_resolve_ggsn_addr() function, I hope:
untested.

Minor cosmetics just to see if you're paying attention... ;)

Sponsored-by: On-Waves ehi

3 files changed, 105 insertions, 35 deletions

diff --git a/openbsc/tests/gtphub/Makefile.am b/openbsc/tests/gtphub/Makefile.am
index ecc6d62f0..d818811d9 100644
--- a/openbsc/tests/gtphub/Makefile.am
+++ b/openbsc/tests/gtphub/Makefile.am
@@ -11,10 +11,12 @@ noinst_PROGRAMS = gtphub_test
 
 gtphub_test_SOURCES = gtphub_test.c
 gtphub_test_LDFLAGS = \
-	-Wl,--wrap=gtphub_resolve_ggsn_addr
+	-Wl,--wrap=gtphub_resolve_ggsn_addr \
+	-Wl,--wrap=gtphub_ares_init
 
 gtphub_test_LDADD = \
 	$(top_builddir)/src/gprs/gtphub.o \
+	$(top_builddir)/src/gprs/gprs_utils.o \
 	$(LIBOSMOCORE_LIBS) \
 	-lgtp -lrt
 
diff --git a/openbsc/tests/gtphub/gtphub_test.c b/openbsc/tests/gtphub/gtphub_test.c
index af8f3ed75..81875f1c7 100644
--- a/openbsc/tests/gtphub/gtphub_test.c
+++ b/openbsc/tests/gtphub/gtphub_test.c
@@ -37,8 +37,6 @@
 
 #define EXPIRE_ALL ((60 * GTPH_TEI_MAPPING_EXPIRY_MINUTES) + 1)
 
-/* Make non-public API accessible */
-
 void gtphub_init(struct gtphub *hub);
 
 void *osmo_gtphub_ctx;
@@ -328,19 +326,75 @@ static void test_expiry(void)
 
 
 /* override, requires '-Wl,--wrap=gtphub_resolve_ggsn_addr' */
-int __real_gtphub_resolve_ggsn_addr(struct gtphub *hub,
-				    struct osmo_sockaddr *result,
-				    struct gtp_packet_desc *p);
-
-struct osmo_sockaddr resolved_ggsn_addr = {.l = 0};
-int __wrap_gtphub_resolve_ggsn_addr(struct gtphub *hub,
-				    struct osmo_sockaddr *result,
-				    struct gtp_packet_desc *p)
+struct gtphub_peer_port *__real_gtphub_resolve_ggsn_addr(struct gtphub *hub,
+							 const char *imsi_str,
+							 const char *apn_ni_str);
+
+struct gsn_addr resolved_ggsn_addr = { 0 };
+uint16_t resolved_ggsn_port = 2123;
+char resolve_ggsn_got_imsi[256];
+char resolve_ggsn_got_ni[256];
+struct gtphub_peer_port *__wrap_gtphub_resolve_ggsn_addr(struct gtphub *hub,
+							 const char *imsi_str,
+							 const char *apn_ni_str)
+{
+	struct gtphub_peer_port *pp;
+	pp = gtphub_port_have(hub, &hub->to_ggsns[GTPH_PLANE_CTRL],
+			      &resolved_ggsn_addr, resolved_ggsn_port);
+	printf("Wrap: returning GGSN addr from imsi %s ni %s: %s\n",
+	       imsi_str, apn_ni_str, gtphub_port_str(pp));
+
+	if (imsi_str) {
+		strncpy(resolve_ggsn_got_imsi, imsi_str, sizeof(resolve_ggsn_got_imsi));
+		resolve_ggsn_got_imsi[sizeof(resolve_ggsn_got_imsi) - 1] = '\0';
+	}
+	else
+		strcpy(resolve_ggsn_got_imsi, "(null)");
+
+	if (apn_ni_str) {
+		strncpy(resolve_ggsn_got_ni, apn_ni_str, sizeof(resolve_ggsn_got_ni));
+		resolve_ggsn_got_ni[sizeof(resolve_ggsn_got_ni) - 1] = '\0';
+	}
+	else
+		strcpy(resolve_ggsn_got_ni, "(null)");
+
+	return pp;
+}
+
+#define was_resolved_for(IMSI,NI) _was_resolved_for(IMSI, NI, __FILE__, __LINE__)
+static int _was_resolved_for(const char *imsi, const char *ni, const char *file, int line)
+{
+	int cmp0 = strncmp(imsi, resolve_ggsn_got_imsi, sizeof(resolve_ggsn_got_imsi));
+
+	if (cmp0 != 0) {
+		printf("\n%s:%d: was_resolved_for(): MISMATCH for IMSI\n"
+		       "  expecting: '%s'\n"
+		       "        got: '%s'\n\n",
+		       file,
+		       line,
+		       imsi, resolve_ggsn_got_imsi);
+	}
+
+	int cmp1 = strncmp(ni, resolve_ggsn_got_ni, sizeof(resolve_ggsn_got_ni));
+	if (cmp1 != 0) {
+		printf("\n%s:%d: was_resolved_for(): MISMATCH for NI\n"
+		       "  expecting: '%s'\n"
+		       "        got: '%s'\n\n",
+		       file,
+		       line,
+		       ni, resolve_ggsn_got_ni);
+	}
+
+	return (cmp0 == 0) && (cmp1 == 0);
+}
+
+/* override, requires '-Wl,--wrap=gtphub_ares_init' */
+int __real_gtphub_ares_init(struct gtphub *hub);
+
+int __wrap_gtphub_ares_init(struct gtphub *hub)
 {
-	osmo_sockaddr_copy(result, &resolved_ggsn_addr);
-	printf("Wrap: returning GGSN addr: %s\n",
-	       osmo_sockaddr_to_str(result));
-	return (resolved_ggsn_addr.l != 0)? 0 : -1;
+	/* Do nothing. */
+	return 0;
 }
 
 #define buf_len 1024
@@ -413,6 +467,9 @@ static void test_echo(void)
 
 	gtphub_init(hub);
 
+	/* TODO This test should test for gtphub echoing back to each side.
+	 * Echos must not be routed through. */
+
 	const char *gtp_ping_from_sgsn =
 		"32"	/* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
 		"01"	/* type 01: Echo request */
@@ -444,16 +501,17 @@ static void test_echo(void)
 		"00" "00" "0e01";
 
 	/* Set the GGSN address that gtphub is forced to resolve to. */
-	OSMO_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_addr,
-					   "192.168.43.34", 434)
+	const char *resolved_ggsn_str = "192.168.43.34";
+	resolved_ggsn_port = 434;
+	OSMO_ASSERT(gsn_addr_from_str(&resolved_ggsn_addr, resolved_ggsn_str)
 		    == 0);
 
-	/* according to spec, we'd always send to port 2123 instead...
-	struct osmo_sockaddr ggsn_standard_port;
-	OSMO_ASSERT(osmo_sockaddr_init_udp(&ggsn_standard_port,
-					   "192.168.43.34", 2123)
+	/* A sockaddr for comparing later */
+	struct osmo_sockaddr resolved_ggsn_sa;
+	OSMO_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_sa,
+					   resolved_ggsn_str,
+					   resolved_ggsn_port)
 		    == 0);
-	 */
 
 	struct osmo_sockaddr orig_sgsn_addr;
 	OSMO_ASSERT(osmo_sockaddr_init(&orig_sgsn_addr,
@@ -467,7 +525,7 @@ static void test_echo(void)
 					    &ggsn_ofd, &ggsn_addr);
 	OSMO_ASSERT(send > 0);
 	OSMO_ASSERT(ggsn_addr.l);
-	OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_addr));
+	OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_sa));
 	OSMO_ASSERT(msg_is(gtp_ping_to_ggsn));
 
 	struct osmo_fd *sgsn_ofd;
@@ -481,7 +539,7 @@ static void test_echo(void)
 
 	struct gtphub_peer_port *ggsn_port =
 		gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
-				    &resolved_ggsn_addr);
+				    &resolved_ggsn_sa);
 	OSMO_ASSERT(ggsn_port);
 	struct gtphub_peer *ggsn = ggsn_port->peer_addr->peer;
 	/* now == 123; now + 30 == 153. */
@@ -515,7 +573,7 @@ static void test_create_pdp_ctx(void)
 	const char *gtp_req_from_sgsn =
 		"32" 	/* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
 		"10" 	/* type 16: Create PDP Context Request */
-		"0067"	/* length = 8 + 103 */
+		"0068"	/* length = 8 + 104 */
 		"00000000" /* No TEI yet */
 		"abcd"	/* Sequence nr */
 		"00"	/* N-PDU 0 */
@@ -536,8 +594,8 @@ static void test_create_pdp_ctx(void)
 		  "0002" /* length = 2: empty PDP Address */
 		  "f121" /* spare 0xf0, PDP organization 1, PDP type number 0x21 = 33 */
 		"83"	/* 131: Access Point Name */
-		  "0008" /* length = 8 */
-		  "696e7465726e6574" /* "internet" */
+		  "0009" /* length */
+		  "08696e7465726e6574" /* "internet" */
 		"84"	/* 132: Protocol Configuration Options */
 		  "0015" /* length = 21 */
 		  "80c0231101010011036d69670868656d6d656c6967"
@@ -557,13 +615,13 @@ static void test_create_pdp_ctx(void)
 		;
 
 	const char *gtp_req_to_ggsn =
-		"32" "10" "0067" "00000000"
+		"32" "10" "0068" "00000000"
 		"6d31"	/* mapped seq ("abcd") */
 		"00" "00" "02" "42000121436587f9" "0e60" "0f01"
 		"10" "00000001" /* mapped TEI Data I ("123") */
 		"11" "00000001" /* mapped TEI Control ("321") */
 		"1400" "1a" "0800" "80" "0002" "f121" "83"
-		"0008" "696e7465726e6574" "84" "0015"
+		"0009" "08696e7465726e6574" "84" "0015"
 		"80c0231101010011036d69670868656d6d656c6967" "85" "0004"
 		"7f000201" /* replaced with gtphub's address ggsn ctrl */
 		"85" "0004"
@@ -627,14 +685,23 @@ static void test_create_pdp_ctx(void)
 		;
 
 	/* Set the GGSN address that gtphub is forced to resolve to. */
-	OSMO_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_addr,
-					   "192.168.43.34", 434)
+	const char *resolved_ggsn_str = "192.168.43.34";
+	resolved_ggsn_port = 434;
+	OSMO_ASSERT(gsn_addr_from_str(&resolved_ggsn_addr, resolved_ggsn_str)
+		    == 0);
+
+	/* A sockaddr for comparing later */
+	struct osmo_sockaddr resolved_ggsn_sa;
+	OSMO_ASSERT(osmo_sockaddr_init_udp(&resolved_ggsn_sa,
+					   resolved_ggsn_str,
+					   resolved_ggsn_port)
 		    == 0);
 
 	struct osmo_sockaddr orig_sgsn_addr;
 	OSMO_ASSERT(osmo_sockaddr_init(&orig_sgsn_addr,
 				       AF_UNSPEC, SOCK_DGRAM, IPPROTO_UDP,
 				       "192.168.42.23", 423) == 0);
+
 	struct osmo_fd *ggsn_ofd = NULL;
 	struct osmo_sockaddr ggsn_addr;
 	int send;
@@ -642,8 +709,9 @@ static void test_create_pdp_ctx(void)
 					    buf, msg(gtp_req_from_sgsn), now,
 					    &ggsn_ofd, &ggsn_addr);
 	OSMO_ASSERT(send > 0);
-	OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_addr));
+	OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_sa));
 	OSMO_ASSERT(msg_is(gtp_req_to_ggsn));
+	OSMO_ASSERT(was_resolved_for("240010123456789", "internet"));
 
 	struct osmo_fd *sgsn_ofd;
 	struct osmo_sockaddr sgsn_addr;
@@ -656,7 +724,7 @@ static void test_create_pdp_ctx(void)
 
 	struct gtphub_peer_port *ggsn_port =
 		gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
-				    &resolved_ggsn_addr);
+				    &resolved_ggsn_sa);
 	OSMO_ASSERT(ggsn_port);
 	struct gtphub_peer *ggsn = ggsn_port->peer_addr->peer;
 	/* now == 345; now + 30 == 375.
diff --git a/openbsc/tests/gtphub/gtphub_test.ok b/openbsc/tests/gtphub/gtphub_test.ok
index 7be13fe86..8d1075ab7 100644
--- a/openbsc/tests/gtphub/gtphub_test.ok
+++ b/openbsc/tests/gtphub/gtphub_test.ok
@@ -1,3 +1,3 @@
-Wrap: returning GGSN addr: 192.168.43.34 port 434
-Wrap: returning GGSN addr: 192.168.43.34 port 434
+Wrap: returning GGSN addr from imsi (null) ni (null): 192.168.43.34 port 434
+Wrap: returning GGSN addr from imsi 240010123456789 ni internet: 192.168.43.34 port 434
 Done