NAT: reload BSCs config dynamically

Add vty tests for BSC configuration reloading.
Load BSCs configuration on bscs-config-file command:
* remove all runtime configured BSC not in the config file
* close connections to all BSC with updated token value

Fixes: OS#1670
Sponsored-by: On-Waves ehf

3 files changed, 153 insertions, 1 deletions

diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index 5ccc02e18..94ab0e5ff 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -35,6 +35,7 @@
 #include <osmocom/gsm/protocol/gsm_04_08.h>
 
 #include <regex.h>
+#include <stdbool.h>
 
 #define DIR_BSC 1
 #define DIR_MSC 2
@@ -164,6 +165,10 @@ struct bsc_config {
 	/* audio handling */
 	int max_endpoints;
 
+	/* used internally for reload handling */
+	bool remove;
+	bool token_updated;
+
 	/* backpointer */
 	struct bsc_nat *nat;
 
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
index b7b49e63a..55f3dbf4f 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_vty.c
@@ -39,6 +39,7 @@
 #include <osmocom/sccp/sccp.h>
 
 #include <stdlib.h>
+#include <stdbool.h>
 
 static struct bsc_nat *_nat;
 
@@ -513,6 +514,8 @@ DEFUN(cfg_nat_include,
 {
 	char *path;
 	int rc;
+	struct bsc_config *cf1, *cf2;
+	struct bsc_connection *con1, *con2;
 
 	if ('/' == argv[0][0])
 		bsc_replace_string(_nat, &_nat->resolved_path, argv[0]);
@@ -523,13 +526,32 @@ DEFUN(cfg_nat_include,
 		talloc_free(path);
 	}
 
+	llist_for_each_entry_safe(cf1, cf2, &_nat->bsc_configs, entry) {
+		cf1->remove = true;
+		cf1->token_updated = false;
+	}
+
 	rc = vty_read_config_file(_nat->resolved_path, NULL);
 	if (rc < 0) {
 		vty_out(vty, "Failed to parse the config file %s: %s%s",
 			_nat->resolved_path, strerror(-rc), VTY_NEWLINE);
 		return CMD_WARNING;
 	}
+
 	bsc_replace_string(_nat, &_nat->include_file, argv[0]);
+
+	llist_for_each_entry_safe(con1, con2, &_nat->bsc_connections,
+				  list_entry) {
+		if (con1->cfg)
+			if (con1->cfg->token_updated || con1->cfg->remove)
+				bsc_close_connection(con1);
+	}
+
+	llist_for_each_entry_safe(cf1, cf2, &_nat->bsc_configs, entry) {
+		if (cf1->remove)
+			bsc_config_free(cf1);
+	}
+
 	return CMD_SUCCESS;
 }
 
@@ -846,6 +868,7 @@ DEFUN(cfg_bsc, cfg_bsc_cmd, "bsc BSC_NR",
 	if (!bsc)
 		return CMD_WARNING;
 
+	bsc->remove = false;
 	vty->index = bsc;
 	vty->node = NAT_BSC_NODE;
 
@@ -858,6 +881,12 @@ DEFUN(cfg_bsc_token, cfg_bsc_token_cmd, "token TOKEN",
 {
 	struct bsc_config *conf = vty->index;
 
+	if (strncmp(conf->token, argv[0], 128) != 0) {
+		vty_out(vty, "updated token: %s -> %s%s", conf->token, argv[0],
+			VTY_NEWLINE);
+		conf->token_updated = true;
+	}
+
 	bsc_replace_string(conf, &conf->token, argv[0]);
 	return CMD_SUCCESS;
 }
diff --git a/openbsc/tests/vty_test_runner.py b/openbsc/tests/vty_test_runner.py
index d57412989..59fdd2f93 100644
--- a/openbsc/tests/vty_test_runner.py
+++ b/openbsc/tests/vty_test_runner.py
@@ -620,12 +620,61 @@ class TestVTYBSC(TestVTYGenericBSC):
 class TestVTYNAT(TestVTYGenericBSC):
 
     def vty_command(self):
-        return ["./src/osmo-bsc_nat/osmo-bsc_nat", "-c",
+        return ["./src/osmo-bsc_nat/osmo-bsc_nat", "-l", "127.0.0.1", "-c",
                 "doc/examples/osmo-bsc_nat/osmo-bsc_nat.cfg"]
 
     def vty_app(self):
         return (4244, "src/osmo-bsc_nat/osmo-bsc_nat",  "OsmoBSCNAT", "nat")
 
+    def testBSCreload(self):
+        # use separate ip to avoid interference with other tests
+        ip = "127.0.0.4"
+        self.vty.enable()
+        bscs1 = self.vty.command("show bscs-config")
+        nat_bsc_reload(self)
+        bscs2 = self.vty.command("show bscs-config")
+        # check that multiple calls to bscs-config-file give the same result
+        self.assertEquals(bscs1, bscs2)
+
+        # add new bsc
+        self.vty.command("configure terminal")
+        self.vty.command("nat")
+        self.vty.command("bsc 5")
+        self.vty.command("token key")
+        self.vty.command("location_area_code 666")
+        self.vty.command("end")
+
+        # update bsc token
+        self.vty.command("configure terminal")
+        self.vty.command("nat")
+        self.vty.command("bsc 1")
+        self.vty.command("token xyu")
+        self.vty.command("end")
+
+        nat_msc_ip(self, ip)
+        msc = nat_msc_test(self, ip)
+        b0 = nat_bsc_sock_test(0, "lol")
+        b1 = nat_bsc_sock_test(1, "xyu")
+        b2 = nat_bsc_sock_test(5, "key")
+
+        self.assertEquals("3 BSCs configured", self.vty.command("show nat num-bscs-configured"))
+        self.assertTrue(3 == nat_bsc_num_con(self))
+        self.assertEquals("MSC is connected: 1", self.vty.command("show msc connection"))
+
+        nat_bsc_reload(self)
+        bscs2 = self.vty.command("show bscs-config")
+        # check that the reset to initial config succeeded
+        self.assertEquals(bscs1, bscs2)
+
+        self.assertEquals("2 BSCs configured", self.vty.command("show nat num-bscs-configured"))
+        self.assertTrue(1 == nat_bsc_num_con(self))
+        rem = self.vty.command("show bsc connections").split(' ')
+        # remaining connection is for BSC0
+        self.assertEquals('0', rem[2])
+        # remaining connection is authorized
+        self.assertEquals('1', rem[4])
+        self.assertEquals("MSC is connected: 1", self.vty.command("show msc connection"))
+
     def testVtyTree(self):
         self.vty.enable()
         self.assertTrue(self.vty.verify('configure terminal', ['']))
@@ -1032,6 +1081,75 @@ def ipa_send_resp(x, tk, verbose = False):
         print "\tBSC -> NAT: IPA ID RESP"
     return x.send("\x00\x07\xfe\x05\x00\x04\x01" + tk)
 
+def nat_bsc_reload(x):
+    x.vty.command("configure terminal")
+    x.vty.command("nat")
+    x.vty.command("bscs-config-file bscs.config")
+    x.vty.command("end")
+
+def nat_msc_ip(x, ip):
+    x.vty.command("configure terminal")
+    x.vty.command("nat")
+    x.vty.command("msc ip " + ip)
+    x.vty.command("end")
+
+def data2str(d):
+    return "".join("{:02x}".format(ord(c)) for c in d)
+
+def nat_msc_test(x, ip, verbose = False):
+    msc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    msc.settimeout(32)
+    msc.bind((ip, 5000))
+    msc.listen(5)
+    if (verbose):
+        print "MSC is ready at " + ip
+    while "MSC is connected: 0" == x.vty.command("show msc connection"):
+        conn, addr = msc.accept()
+        if (verbose):
+            print "MSC got connection from ", addr
+    return conn
+
+def ipa_handle_small(x, verbose = False):
+    s = data2str(x.recv(4))
+    if "0001fe00" == s:
+        if (verbose):
+            print "\tBSC <- NAT: PING?"
+        ipa_send_pong(x, verbose)
+    elif "0001fe06" == s:
+        if (verbose):
+            print "\tBSC <- NAT: IPA ID ACK"
+        ipa_send_ack(x, verbose)
+    elif "0001fe00" == s:
+        if (verbose):
+            print "\tBSC <- NAT: PONG!"
+    else:
+        if (verbose):
+            print "\tBSC <- NAT: ", s
+
+def ipa_handle_resp(x, tk, verbose = False):
+    s = data2str(x.recv(38))
+    if "0023fe040108010701020103010401050101010011" in s:
+         ipa_send_resp(x, tk, verbose)
+    else:
+        if (verbose):
+            print "\tBSC <- NAT: ", s
+
+def nat_bsc_num_con(x):
+    return len(x.vty.command("show bsc connections").split('\n'))
+
+def nat_bsc_sock_test(nr, tk, verbose = False):
+    bsc = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    bsc.bind(('127.0.0.1' + str(nr), 0))
+    bsc.connect(('127.0.0.1', 5000))
+    if (verbose):
+        print "BSC%d " %nr
+        print "\tconnected to %s:%d" % bsc.getpeername()
+    ipa_handle_small(bsc, verbose)
+    ipa_handle_resp(bsc, tk, verbose)
+    bsc.recv(27) # MGCP msg
+    ipa_handle_small(bsc, verbose)
+    return bsc
+
 def add_bsc_test(suite, workdir):
     if not os.path.isfile(os.path.join(workdir, "src/osmo-bsc/osmo-bsc")):
         print("Skipping the BSC test")