recv SYN after FIN or RST is considered to be TCP port reuse

This commit is contained in:
luwenpeng
2024-05-17 17:38:08 +08:00
parent 32ae4618ef
commit c22e4e5955
5 changed files with 36 additions and 19 deletions

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@@ -658,7 +658,8 @@ static struct session *session_manager_lookup_tcp_session(struct session_manager
enum flow_direction dir = identify_direction_by_history(sess, key); enum flow_direction dir = identify_direction_by_history(sess, key);
struct tcp_half *half = &sess->tcp_halfs[dir]; struct tcp_half *half = &sess->tcp_halfs[dir];
if (half->isn && half->isn != tcp_hdr_get_seq(hdr)) if ((half->isn && half->isn != tcp_hdr_get_seq(hdr)) || // recv SYN with different ISN
((half->history & TH_FIN) || (half->history & TH_RST))) // recv SYN after FIN or RST
{ {
// TCP port reuse, evict old session // TCP port reuse, evict old session
session_manager_evicte_session(mgr, sess, now, PORT_REUSE_EVICT); session_manager_evicte_session(mgr, sess, now, PORT_REUSE_EVICT);

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@@ -24,15 +24,16 @@ extern "C"
struct tcp_half struct tcp_half
{ {
struct tcp_reassembly *assembler; struct tcp_reassembly *assembler;
struct tcp_segment in_order; struct tcp_segment in_order; // current packet in order segment
uint32_t in_order_ref; uint32_t in_order_ref; // reference count of current packet in order segment
uint32_t isn; uint32_t seq; // current packet sequence number
uint32_t seq; uint32_t ack; // current packet ack number
uint32_t ack; uint16_t len; // current packet payload length
uint16_t len; uint8_t flags; // current packet flags
uint8_t flags;
uint8_t history; uint32_t isn; // current direction initial sequence number
uint8_t history; // current direction received flags
}; };
/* /*

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@@ -21,19 +21,19 @@ struct session_transition
* SESSION_STATE_OPENING -> SESSION_STATE_ACTIVE ( TCP_DATA | UDP_DATA ) * SESSION_STATE_OPENING -> SESSION_STATE_ACTIVE ( TCP_DATA | UDP_DATA )
* SESSION_STATE_OPENING -> SESSION_STATE_CLOSING ( TCP_FIN | TCP_RST | TIMEOUT ) * SESSION_STATE_OPENING -> SESSION_STATE_CLOSING ( TCP_FIN | TCP_RST | TIMEOUT )
* SESSION_STATE_OPENING -> SESSION_STATE_DISCARD ( USER_CLOSE ) * SESSION_STATE_OPENING -> SESSION_STATE_DISCARD ( USER_CLOSE )
* SESSION_STATE_OPENING -> SESSION_STATE_CLOSED ( LRU_EVICT ) * SESSION_STATE_OPENING -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT )
* *
* SESSION_STATE_ACTIVE -> SESSION_STATE_ACTIVE ( NONE ) * SESSION_STATE_ACTIVE -> SESSION_STATE_ACTIVE ( NONE )
* SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSING ( TCP_FIN | TCP_RST | TIMEOUT ) * SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSING ( TCP_FIN | TCP_RST | TIMEOUT )
* SESSION_STATE_ACTIVE -> SESSION_STATE_DISCARD ( USER_CLOSE ) * SESSION_STATE_ACTIVE -> SESSION_STATE_DISCARD ( USER_CLOSE )
* SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSED ( LRU_EVICT ) * SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT)
* *
* SESSION_STATE_CLOSING -> SESSION_STATE_CLOSING ( NONE ) * SESSION_STATE_CLOSING -> SESSION_STATE_CLOSING ( NONE )
* SESSION_STATE_CLOSING -> SESSION_STATE_DISCARD ( USER_CLOSE ) * SESSION_STATE_CLOSING -> SESSION_STATE_DISCARD ( USER_CLOSE )
* SESSION_STATE_CLOSING -> SESSION_STATE_CLOSED ( LRU_EVICT | TIMEOUT ) * SESSION_STATE_CLOSING -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT )
* *
* SESSION_STATE_DISCARD -> SESSION_STATE_DISCARD ( NONE ) * SESSION_STATE_DISCARD -> SESSION_STATE_DISCARD ( NONE )
* SESSION_STATE_DISCARD -> SESSION_STATE_CLOSED ( LRU_EVICT | TIMEOUT ) * SESSION_STATE_DISCARD -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT )
*/ */
static void session_inputs_to_str(int inputs, char *buff, int len) static void session_inputs_to_str(int inputs, char *buff, int len)

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@@ -243,7 +243,7 @@ int build_tcp_packet(const struct packet *first, uint16_t ip_id, uint8_t ip_ttl,
switch (curr->type) switch (curr->type)
{ {
case LAYER_TYPE_TCP: case LAYER_TYPE_TCP:
trim = curr->hdr_len + curr->pld_len - sizeof(struct tcphdr) + pld_len; trim = curr->hdr_len + curr->pld_len - sizeof(struct tcphdr) - pld_len;
if (len - trim > buff_size) if (len - trim > buff_size)
{ {
return -ENOMEM; return -ENOMEM;
@@ -330,7 +330,7 @@ int build_udp_packet(const struct packet *first, const char *udp_pld, int pld_le
switch (curr->type) switch (curr->type)
{ {
case LAYER_TYPE_UDP: case LAYER_TYPE_UDP:
trim = curr->hdr_len + curr->pld_len - sizeof(struct udphdr) + pld_len; trim = curr->hdr_len + curr->pld_len - sizeof(struct udphdr) - pld_len;
if (len - trim > buff_size) if (len - trim > buff_size)
{ {
return -ENOMEM; return -ENOMEM;

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@@ -51,16 +51,23 @@ struct inject_rule
static void inject_packet_plugin(struct session *sess, struct packet *pkt, struct inject_rule *rule) static void inject_packet_plugin(struct session *sess, struct packet *pkt, struct inject_rule *rule)
{ {
char buffer[1024] = {0};
const struct tuple6 *tuple = session_get_tuple6(sess); const struct tuple6 *tuple = session_get_tuple6(sess);
if (rule->ip_type == 4 && memcmp(&tuple->src_addr.v4, &rule->v4, sizeof(struct in_addr)) && memcmp(&tuple->dst_addr.v4, &rule->v4, sizeof(struct in_addr))) if (rule->ip_type == 4 &&
memcmp(&tuple->src_addr.v4, &rule->v4, sizeof(struct in_addr)) &&
memcmp(&tuple->dst_addr.v4, &rule->v4, sizeof(struct in_addr)))
{ {
return; return;
} }
if (rule->ip_type == 6 && memcmp(&tuple->src_addr.v6, &rule->v6, sizeof(struct in6_addr)) && memcmp(&tuple->dst_addr.v6, &rule->v6, sizeof(struct in6_addr))) if (rule->ip_type == 6 &&
memcmp(&tuple->src_addr.v6, &rule->v6, sizeof(struct in6_addr)) &&
memcmp(&tuple->dst_addr.v6, &rule->v6, sizeof(struct in6_addr)))
{ {
return; return;
} }
if (rule->port != 0 && tuple->src_port != rule->port && tuple->dst_port != rule->port) if (rule->port != 0 &&
tuple->src_port != rule->port &&
tuple->dst_port != rule->port)
{ {
return; return;
} }
@@ -72,7 +79,8 @@ static void inject_packet_plugin(struct session *sess, struct packet *pkt, struc
{ {
return; return;
} }
if (session_get_stat(sess, FLOW_DIRECTION_C2S, STAT_INJECTED_PACKETS_SUCCESS) > 0 && session_get_stat(sess, FLOW_DIRECTION_S2C, STAT_INJECTED_PACKETS_SUCCESS) > 0) if (session_get_stat(sess, FLOW_DIRECTION_C2S, STAT_INJECTED_PACKETS_SUCCESS) > 0 ||
session_get_stat(sess, FLOW_DIRECTION_S2C, STAT_INJECTED_PACKETS_SUCCESS) > 0)
{ {
return; return;
} }
@@ -89,6 +97,13 @@ static void inject_packet_plugin(struct session *sess, struct packet *pkt, struc
EXPECT_TRUE(stellar_inject_tcp_fin(sess, FLOW_DIRECTION_S2C) > 0); EXPECT_TRUE(stellar_inject_tcp_fin(sess, FLOW_DIRECTION_S2C) > 0);
break; break;
case INJECT_TYPE_TCP_PAYLOAD: case INJECT_TYPE_TCP_PAYLOAD:
packet_set_action(pkt, PACKET_ACTION_DROP);
snprintf(buffer, sizeof(buffer), "HTTP/1.1 200 OK\r\nContent-Length: %d\r\n\r\n%s", 5 + 5 + 2, "Hello");
EXPECT_TRUE(stellar_inject_payload(sess, FLOW_DIRECTION_S2C, buffer, strlen(buffer)) > 0); // inject payload to client
EXPECT_TRUE(stellar_inject_payload(sess, FLOW_DIRECTION_S2C, "World\r\n", 7) > 0);
EXPECT_TRUE(stellar_inject_tcp_fin(sess, FLOW_DIRECTION_S2C) > 0); // inject FIN to client
EXPECT_TRUE(stellar_inject_tcp_rst(sess, FLOW_DIRECTION_C2S) > 0); // inject RST to server
break;
case INJECT_TYPE_UDP_PAYLOAD: case INJECT_TYPE_UDP_PAYLOAD:
packet_set_action(pkt, PACKET_ACTION_DROP); packet_set_action(pkt, PACKET_ACTION_DROP);
EXPECT_TRUE(stellar_inject_payload(sess, FLOW_DIRECTION_C2S, "Hello Server", 12) > 0); EXPECT_TRUE(stellar_inject_payload(sess, FLOW_DIRECTION_C2S, "Hello Server", 12) > 0);