gtphub: fix Echo behavior: respond directly.
Up to now I used the Echo as a test for sequence nr mappings. But Echos
should be handled differently: they are scoped on the link and an Echo
response should be sent right back to the requester.
Sponsored-by: On-Waves ehi
diff --git a/openbsc/include/openbsc/gtphub.h b/openbsc/include/openbsc/gtphub.h
index 05eee85..514b1a3 100644
--- a/openbsc/include/openbsc/gtphub.h
+++ b/openbsc/include/openbsc/gtphub.h
@@ -396,6 +396,8 @@
struct osmo_timer_list gc_timer;
struct expiry expire_seq_maps;
struct expiry expire_tei_maps;
+
+ uint16_t restart_counter;
};
struct gtp_packet_desc;
@@ -425,6 +427,7 @@
uint8_t *buf,
size_t received,
time_t now,
+ uint8_t **reply_buf,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr);
@@ -434,6 +437,7 @@
uint8_t *buf,
size_t received,
time_t now,
+ uint8_t **reply_buf,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr);
diff --git a/openbsc/src/gprs/gtphub.c b/openbsc/src/gprs/gtphub.c
index eae4cf2..389a0ca 100644
--- a/openbsc/src/gprs/gtphub.c
+++ b/openbsc/src/gprs/gtphub.c
@@ -1222,6 +1222,7 @@
struct osmo_sockaddr to_addr;
struct osmo_fd *to_ofd;
size_t len;
+ uint8_t *reply_buf;
len = gtphub_read(from_ggsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
@@ -1229,11 +1230,11 @@
len = gtphub_from_ggsns_handle_buf(hub, plane_idx, &from_addr, buf, len,
gtphub_now(),
- &to_ofd, &to_addr);
+ &reply_buf, &to_ofd, &to_addr);
if (len < 1)
return 0;
- return gtphub_write(to_ofd, &to_addr, buf, len);
+ return gtphub_write(to_ofd, &to_addr, reply_buf, len);
}
static int gtphub_unmap(struct gtphub *hub,
@@ -1311,10 +1312,33 @@
return osmo_sockaddr_init_udp(dst, gsn_addr_to_str(src), port);
}
-static int gtphub_handle_echo(const struct gtp_packet_desc *p)
+/* If p is an Echo request, replace p's data with the matching response and
+ * return 1. If p is no Echo request, return 0, or -1 if an invalid packet is
+ * detected. */
+static int gtphub_handle_echo(struct gtphub *hub, struct gtp_packet_desc *p, uint8_t **reply_buf)
{
- /* TODO */
- return 0;
+ if (p->type != GTP_ECHO_REQ)
+ return 0;
+
+ static uint8_t echo_response_data[14] = {
+ 0x32, /* flags */
+ GTP_ECHO_RSP,
+ 0x00, 14 - 8, /* Length in network byte order */
+ 0x00, 0x00, 0x00, 0x00, /* Zero TEI */
+ 0, 0, /* Seq, to be replaced */
+ 0, 0, /* no extensions */
+ 0x0e, /* Recovery IE */
+ 0 /* Recovery counter, to be replaced */
+ };
+ uint16_t *seq = (uint16_t*)&echo_response_data[8];
+ uint8_t *recovery = &echo_response_data[13];
+
+ *seq = hton16(p->seq);
+ *recovery = hub->restart_counter;
+
+ *reply_buf = echo_response_data;
+
+ return sizeof(echo_response_data);
}
/* Parse buffer as GTP packet, replace elements in-place and return the ofd and
@@ -1328,29 +1352,30 @@
uint8_t *buf,
size_t received,
time_t now,
+ uint8_t **reply_buf,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr)
{
LOG("<- rx from GGSN %s\n", osmo_sockaddr_to_str(from_addr));
- *to_ofd = &hub->to_sgsns[plane_idx].ofd;
-
static struct gtp_packet_desc p;
gtp_decode(buf, received, plane_idx, &p);
if (p.rc <= 0)
return -1;
- int rc;
- rc = gtphub_handle_echo(&p);
- if (rc == 1) {
- /* It was en echo. Nothing left to do. */
- /* (*to_ofd already set above.) */
+ int reply_len;
+ reply_len = gtphub_handle_echo(hub, &p, reply_buf);
+ if (reply_len > 0) {
+ /* It was an echo. Nothing left to do. */
osmo_sockaddr_copy(to_addr, from_addr);
- return 0;
+ *to_ofd = &hub->to_ggsns[plane_idx].ofd;
+ return reply_len;
}
- if (rc < 0)
- return -1; /* Invalid packet. */
+ if (reply_len < 0)
+ return -1;
+
+ *to_ofd = &hub->to_sgsns[plane_idx].ofd;
/* If a GGSN proxy is configured, check that it's indeed that proxy
* talking to us. A proxy is a forced 1:1 connection, e.g. to another
@@ -1418,6 +1443,8 @@
gtphub_map_seq(&p, ggsn, sgsn, now);
osmo_sockaddr_copy(to_addr, &sgsn->sa);
+
+ *reply_buf = (uint8_t*)p.data;
return received;
}
@@ -1437,6 +1464,7 @@
struct osmo_sockaddr to_addr;
struct osmo_fd *to_ofd;
size_t len;
+ uint8_t *reply_buf;
len = gtphub_read(from_sgsns_ofd, &from_addr, buf, sizeof(buf));
if (len < 1)
@@ -1444,11 +1472,11 @@
len = gtphub_from_sgsns_handle_buf(hub, plane_idx, &from_addr, buf, len,
gtphub_now(),
- &to_ofd, &to_addr);
+ &reply_buf, &to_ofd, &to_addr);
if (len < 1)
return 0;
- return gtphub_write(to_ofd, &to_addr, buf, len);
+ return gtphub_write(to_ofd, &to_addr, reply_buf, len);
}
/* Analogous to gtphub_from_ggsns_handle_buf(), see the comment there. */
@@ -1458,29 +1486,30 @@
uint8_t *buf,
size_t received,
time_t now,
+ uint8_t **reply_buf,
struct osmo_fd **to_ofd,
struct osmo_sockaddr *to_addr)
{
LOG("-> rx from SGSN %s\n", osmo_sockaddr_to_str(from_addr));
- *to_ofd = &hub->to_ggsns[plane_idx].ofd;
-
static struct gtp_packet_desc p;
gtp_decode(buf, received, plane_idx, &p);
if (p.rc <= 0)
return -1;
- int rc;
- rc = gtphub_handle_echo(&p);
- if (rc == 1) {
- /* It was en echo. Nothing left to do. */
- /* (*to_ofd already set above.) */
+ int reply_len;
+ reply_len = gtphub_handle_echo(hub, &p, reply_buf);
+ if (reply_len > 0) {
+ /* It was an echo. Nothing left to do. */
osmo_sockaddr_copy(to_addr, from_addr);
- return 0;
+ *to_ofd = &hub->to_ggsns[plane_idx].ofd;
+ return reply_len;
}
- if (rc < 0)
- return -1; /* Invalid packet. */
+ if (reply_len < 0)
+ return -1;
+
+ *to_ofd = &hub->to_ggsns[plane_idx].ofd;
/* If an SGSN proxy is configured, check that it's indeed that proxy
* talking to us. A proxy is a forced 1:1 connection, e.g. to another
@@ -1583,6 +1612,7 @@
osmo_sockaddr_copy(to_addr, &ggsn->sa);
+ *reply_buf = (uint8_t*)p.data;
return received;
}
@@ -1764,6 +1794,8 @@
gtphub_init(hub);
gtphub_ares_init(hub);
+ /* TODO set hub->restart_counter from external file. */
+
int plane_idx;
for (plane_idx = 0; plane_idx < GTPH_PLANE_N; plane_idx++) {
rc = gtphub_bind_start(&hub->to_ggsns[plane_idx],
diff --git a/openbsc/tests/gtphub/gtphub_test.c b/openbsc/tests/gtphub/gtphub_test.c
index 81875f1..7839050 100644
--- a/openbsc/tests/gtphub/gtphub_test.c
+++ b/openbsc/tests/gtphub/gtphub_test.c
@@ -399,6 +399,7 @@
#define buf_len 1024
static uint8_t buf[buf_len];
+static uint8_t *reply_buf;
static unsigned int msg(const char *hex)
{
@@ -410,16 +411,16 @@
/* Compare static buf to given string constant. The amount of bytes is obtained
* from parsing the GTP header in buf. hex must match an osmo_hexdump() of the
* desired message. Return 1 if size and content match. */
-#define msg_is(MSG) _msg_is(MSG, __FILE__, __LINE__)
-static int _msg_is(const char *hex, const char *file, int line)
+#define reply_is(MSG) _reply_is(MSG, __FILE__, __LINE__)
+static int _reply_is(const char *hex, const char *file, int line)
{
- struct gtp1_header_long *h = (void*)buf;
+ struct gtp1_header_long *h = (void*)reply_buf;
int len = ntoh16(h->length) + 8;
- const char *dump = osmo_hexdump_nospc(buf, len);
+ const char *dump = osmo_hexdump_nospc(reply_buf, len);
int cmp = strcmp(dump, hex);
if (cmp != 0) {
- printf("\n%s:%d: msg_is(): MISMATCH\n"
+ printf("\n%s:%d: reply_is(): MISMATCH\n"
" expecting:\n'%s'\n"
" got:\n'%s'\n\n",
file,
@@ -466,87 +467,82 @@
time_t now = 123;
gtphub_init(hub);
-
- /* TODO This test should test for gtphub echoing back to each side.
- * Echos must not be routed through. */
+ hub->restart_counter = 0x23;
const char *gtp_ping_from_sgsn =
"32" /* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
"01" /* type 01: Echo request */
"0004" /* length of 4 after header TEI */
"00000000" /* header TEI == 0 in Echo */
- "abcd" /* some 16 octet sequence nr */
+ "abcd" /* some 2 octet sequence nr */
"0000" /* N-PDU 0, no extension header (why is this here?) */
;
- /* Same with mapped sequence number */
- const char *gtp_ping_to_ggsn =
- "32" "01" "0004" "00000000"
- "6d31" /* mapped seq */
- "00" "00";
-
- const char *gtp_pong_from_ggsn =
+ const char *gtp_pong_to_sgsn =
"32"
"02" /* type 02: Echo response */
- "0006" /* len */
- "00000000" /* tei */
- "6d31" /* mapped seq */
- "0000" /* ext */
- "0e01" /* 0e: Recovery, val == 1 */
+ "0006" /* length of 6 after header TEI */
+ "00000000" /* header TEI == 0 in Echo */
+ "abcd" /* same sequence nr */
+ "0000"
+ "0e23" /* Recovery with restart counter */
;
- /* Same with unmapped sequence number */
- const char *gtp_pong_to_sgsn =
- "32" "02" "0006" "00000000"
- "abcd" /* unmapped seq */
- "00" "00" "0e01";
-
- /* Set the GGSN address that gtphub is forced to resolve to. */
- 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);
+ OSMO_ASSERT(osmo_sockaddr_init_udp(&orig_sgsn_addr,
+ "192.168.42.23", 423) == 0);
struct osmo_fd *ggsn_ofd = NULL;
- struct osmo_sockaddr ggsn_addr;
+ struct osmo_sockaddr to_addr;
int send;
send = gtphub_from_sgsns_handle_buf(hub, GTPH_PLANE_CTRL, &orig_sgsn_addr,
buf, msg(gtp_ping_from_sgsn), now,
- &ggsn_ofd, &ggsn_addr);
+ &reply_buf, &ggsn_ofd, &to_addr);
OSMO_ASSERT(send > 0);
- OSMO_ASSERT(ggsn_addr.l);
- OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_sa));
- OSMO_ASSERT(msg_is(gtp_ping_to_ggsn));
+ OSMO_ASSERT(to_addr.l);
+ OSMO_ASSERT(same_addr(&to_addr, &orig_sgsn_addr));
+ OSMO_ASSERT(reply_is(gtp_pong_to_sgsn));
- struct osmo_fd *sgsn_ofd;
- struct osmo_sockaddr sgsn_addr;
- send = gtphub_from_ggsns_handle_buf(hub, GTPH_PLANE_CTRL, &ggsn_addr,
- buf, msg(gtp_pong_from_ggsn), now,
- &sgsn_ofd, &sgsn_addr);
+ struct gtphub_peer_port *sgsn_port =
+ gtphub_port_find_sa(&hub->to_sgsns[GTPH_PLANE_CTRL],
+ &orig_sgsn_addr);
+ /* We don't record Echo peers. */
+ OSMO_ASSERT(!sgsn_port);
+
+ const char *gtp_ping_from_ggsn =
+ "32" /* 0b001'1 0010: version 1, protocol GTP, with seq nr. */
+ "01" /* type 01: Echo request */
+ "0004" /* length of 4 after header TEI */
+ "00000000" /* header TEI == 0 in Echo */
+ "cdef" /* some 2 octet sequence nr */
+ "0000" /* N-PDU 0, no extension header (why is this here?) */
+ ;
+
+ const char *gtp_pong_to_ggsn =
+ "32"
+ "02" /* type 02: Echo response */
+ "0006" /* length of 6 after header TEI */
+ "00000000" /* header TEI == 0 in Echo */
+ "cdef" /* same sequence nr */
+ "0000"
+ "0e23" /* Recovery with restart counter */
+ ;
+
+ struct osmo_sockaddr orig_ggsn_addr;
+ OSMO_ASSERT(osmo_sockaddr_init_udp(&orig_ggsn_addr,
+ "192.168.24.32", 321) == 0);
+ struct osmo_fd *sgsn_ofd = NULL;
+ send = gtphub_from_ggsns_handle_buf(hub, GTPH_PLANE_CTRL, &orig_ggsn_addr,
+ buf, msg(gtp_ping_from_ggsn), now,
+ &reply_buf, &sgsn_ofd, &to_addr);
OSMO_ASSERT(send > 0);
- OSMO_ASSERT(same_addr(&sgsn_addr, &orig_sgsn_addr));
- OSMO_ASSERT(msg_is(gtp_pong_to_sgsn));
+ OSMO_ASSERT(same_addr(&to_addr, &orig_ggsn_addr));
+ OSMO_ASSERT(reply_is(gtp_pong_to_ggsn));
struct gtphub_peer_port *ggsn_port =
gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
- &resolved_ggsn_sa);
- OSMO_ASSERT(ggsn_port);
- struct gtphub_peer *ggsn = ggsn_port->peer_addr->peer;
- /* now == 123; now + 30 == 153. */
- OSMO_ASSERT(nr_map_is(&ggsn->seq_map, "(43981->27953@153), "));
-
- OSMO_ASSERT(nr_map_is(&hub->tei_map[GTPH_PLANE_CTRL], ""));
- OSMO_ASSERT(nr_map_is(&hub->tei_map[GTPH_PLANE_USER], ""));
+ &orig_sgsn_addr);
+ /* We don't record Echo peers. */
+ OSMO_ASSERT(!ggsn_port);
gtphub_gc(hub, now + EXPIRE_ALL);
}
@@ -707,20 +703,20 @@
int send;
send = gtphub_from_sgsns_handle_buf(hub, GTPH_PLANE_CTRL, &orig_sgsn_addr,
buf, msg(gtp_req_from_sgsn), now,
- &ggsn_ofd, &ggsn_addr);
+ &reply_buf, &ggsn_ofd, &ggsn_addr);
OSMO_ASSERT(send > 0);
OSMO_ASSERT(same_addr(&ggsn_addr, &resolved_ggsn_sa));
- OSMO_ASSERT(msg_is(gtp_req_to_ggsn));
+ OSMO_ASSERT(reply_is(gtp_req_to_ggsn));
OSMO_ASSERT(was_resolved_for("240010123456789", "internet"));
struct osmo_fd *sgsn_ofd;
struct osmo_sockaddr sgsn_addr;
send = gtphub_from_ggsns_handle_buf(hub, GTPH_PLANE_CTRL, &ggsn_addr,
buf, msg(gtp_resp_from_ggsn), now,
- &sgsn_ofd, &sgsn_addr);
+ &reply_buf, &sgsn_ofd, &sgsn_addr);
OSMO_ASSERT(send > 0);
OSMO_ASSERT(same_addr(&sgsn_addr, &orig_sgsn_addr));
- OSMO_ASSERT(msg_is(gtp_resp_to_sgsn));
+ OSMO_ASSERT(reply_is(gtp_resp_to_sgsn));
struct gtphub_peer_port *ggsn_port =
gtphub_port_find_sa(&hub->to_ggsns[GTPH_PLANE_CTRL],
diff --git a/openbsc/tests/gtphub/gtphub_test.ok b/openbsc/tests/gtphub/gtphub_test.ok
index 8d1075a..eac6f0c 100644
--- a/openbsc/tests/gtphub/gtphub_test.ok
+++ b/openbsc/tests/gtphub/gtphub_test.ok
@@ -1,3 +1,2 @@
-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