nat: TCP state tracking based on RFC 7857/RFC 6146
[vpp.git] / src / plugins / nat / nat44-ed / nat44_ed.h
index 4665f7c..0706785 100644 (file)
@@ -63,10 +63,6 @@ typedef enum nat44_config_flags_t_
 
 typedef struct
 {
-  /* nat44 plugin features */
-  u8 static_mapping_only;
-  u8 connection_tracking;
-
   u32 inside_vrf;
   u32 outside_vrf;
 
@@ -109,33 +105,12 @@ typedef enum
 #undef _
 } nat_addr_and_port_alloc_alg_t;
 
-/* Session state */
-#define foreach_snat_session_state          \
-  _(0, UNKNOWN, "unknown")                 \
-  _(1, UDP_ACTIVE, "udp-active")           \
-  _(2, TCP_SYN_SENT, "tcp-syn-sent")       \
-  _(3, TCP_ESTABLISHED, "tcp-established") \
-  _(4, TCP_FIN_WAIT, "tcp-fin-wait")       \
-  _(5, TCP_CLOSE_WAIT, "tcp-close-wait")   \
-  _(6, TCP_CLOSING, "tcp-closing")         \
-  _(7, TCP_LAST_ACK, "tcp-last-ack")       \
-  _(8, TCP_CLOSED, "tcp-closed")           \
-  _(9, ICMP_ACTIVE, "icmp-active")
-
-typedef enum
-{
-#define _(v, N, s) SNAT_SESSION_##N = v,
-  foreach_snat_session_state
-#undef _
-} snat_session_state_t;
-
 #define foreach_nat_in2out_ed_error                                           \
   _ (UNSUPPORTED_PROTOCOL, "unsupported protocol")                            \
   _ (OUT_OF_PORTS, "out of ports")                                            \
   _ (BAD_ICMP_TYPE, "unsupported ICMP type")                                  \
   _ (MAX_SESSIONS_EXCEEDED, "maximum sessions exceeded")                      \
   _ (NON_SYN, "non-SYN packet try to create session")                         \
-  _ (TCP_CLOSED, "drops due to TCP in transitory timeout")                    \
   _ (TRNSL_FAILED, "couldn't translate packet")
 
 typedef enum
@@ -165,15 +140,43 @@ typedef enum
     NAT_OUT2IN_ED_N_ERROR,
 } nat_out2in_ed_error_t;
 
+typedef enum
+{
+  NAT44_ED_TCP_FLAG_NONE = 0,
+  NAT44_ED_TCP_FLAG_FIN,
+  NAT44_ED_TCP_FLAG_SYN,
+  NAT44_ED_TCP_FLAG_SYNFIN,
+  NAT44_ED_TCP_FLAG_RST,
+  NAT44_ED_TCP_FLAG_FINRST,
+  NAT44_ED_TCP_FLAG_SYNRST,
+  NAT44_ED_TCP_FLAG_SYNFINRST,
+  NAT44_ED_TCP_N_FLAG,
+} nat44_ed_tcp_flag_e;
+
+typedef enum
+{
+  NAT44_ED_DIR_I2O = 0,
+  NAT44_ED_DIR_O2I,
+  NAT44_ED_N_DIR,
+} nat44_ed_dir_e;
 
 /* Endpoint dependent TCP session state */
-#define NAT44_SES_I2O_FIN 1
-#define NAT44_SES_O2I_FIN 2
-#define NAT44_SES_I2O_FIN_ACK 4
-#define NAT44_SES_O2I_FIN_ACK 8
-#define NAT44_SES_I2O_SYN 16
-#define NAT44_SES_O2I_SYN 32
-#define NAT44_SES_RST     64
+typedef enum
+{
+  NAT44_ED_TCP_STATE_CLOSED = 0,
+  NAT44_ED_TCP_STATE_SYN_I2O,
+  NAT44_ED_TCP_STATE_SYN_O2I,
+  NAT44_ED_TCP_STATE_ESTABLISHED,
+  NAT44_ED_TCP_STATE_FIN_I2O,
+  NAT44_ED_TCP_STATE_FIN_O2I,
+  NAT44_ED_TCP_STATE_RST_TRANS,
+  NAT44_ED_TCP_STATE_FIN_TRANS,
+  NAT44_ED_TCP_STATE_FIN_REOPEN_SYN_I2O,
+  NAT44_ED_TCP_STATE_FIN_REOPEN_SYN_O2I,
+  NAT44_ED_TCP_N_STATE,
+} nat44_ed_tcp_state_e;
+
+format_function_t format_nat44_ed_tcp_state;
 
 /* Session flags */
 #define SNAT_SESSION_FLAG_STATIC_MAPPING     (1 << 0)
@@ -345,10 +348,7 @@ typedef CLIB_PACKED(struct
   u16 ext_host_nat_port;
 
   /* TCP session state */
-  u8 state;
-  u32 i2o_fin_seq;
-  u32 o2i_fin_seq;
-  u64 tcp_closed_timestamp;
+  nat44_ed_tcp_state_e tcp_state;
 
   /* per vrf sessions index */
   u32 per_vrf_sessions_index;
@@ -359,7 +359,10 @@ typedef CLIB_PACKED(struct
 typedef struct
 {
   ip4_address_t addr;
+  ip4_address_t net;
+  u32 sw_if_index;
   u32 fib_index;
+  u32 addr_len;
 } snat_address_t;
 
 typedef struct
@@ -447,6 +450,7 @@ typedef struct
 
 typedef struct
 {
+  u8 is_resolved;
   ip4_address_t l_addr;
   ip4_address_t pool_addr;
   u16 l_port;
@@ -455,13 +459,22 @@ typedef struct
   u32 vrf_id;
   ip_protocol_t proto;
   u32 flags;
-  int addr_only;
-  int twice_nat;
-  int out2in_only;
-  int identity_nat;
-  int exact;
   u8 *tag;
-} snat_static_map_resolve_t;
+} snat_static_mapping_resolve_t;
+
+typedef struct
+{
+  u8 is_resolved;
+  u8 is_twice_nat;
+  u32 sw_if_index;
+} snat_address_resolve_t;
+
+typedef struct
+{
+  u32 count;
+  u32 sw_if_index;
+  ip4_address_t addr;
+} snat_fib_entry_reg_t;
 
 typedef struct
 {
@@ -535,9 +548,8 @@ typedef struct snat_main_s
   /* Vector of twice NAT addresses for external hosts */
   snat_address_t *twice_nat_addresses;
 
-  /* sw_if_indices whose intfc addresses should be auto-added */
-  u32 *auto_add_sw_if_indices;
-  u32 *auto_add_sw_if_indices_twice_nat;
+  /* first interface address should be auto-added */
+  snat_address_resolve_t *addr_to_resolve;
 
   /* Address and port allocation function */
   nat_alloc_out_addr_and_port_function_t *alloc_addr_and_port;
@@ -557,8 +569,11 @@ typedef struct snat_main_s
   /* vector of outside fibs */
   nat_outside_fib_t *outside_fibs;
 
+  /* vector of fib entries */
+  snat_fib_entry_reg_t *fib_entry_reg;
+
   /* vector of interface address static mappings to resolve. */
-  snat_static_map_resolve_t *to_resolve;
+  snat_static_mapping_resolve_t *sm_to_resolve;
 
   /* Randomize port allocation order */
   u32 random_seed;
@@ -578,10 +593,6 @@ typedef struct snat_main_s
   /* If forwarding is enabled */
   u8 forwarding_enabled;
 
-  /* static mapping config */
-  u8 static_mapping_only;
-  u8 static_mapping_connection_tracking;
-
   /* Is translation memory size calculated or user defined */
   u8 translation_memory_size_set;
 
@@ -653,9 +664,6 @@ typedef struct snat_main_s
   fib_source_t fib_src_hi;
   fib_source_t fib_src_low;
 
-  /* pat - dynamic mapping enabled or conneciton tracking */
-  u8 pat;
-
   /* number of worker handoff frame queue elements */
   u32 frame_queue_nelts;
 
@@ -664,6 +672,16 @@ typedef struct snat_main_s
 
   vnet_main_t *vnet_main;
 
+  /* TCP session state machine table:
+   *   first dimension is possible states
+   *   second dimension is direction (in2out/out2in)
+   *   third dimension is TCP flag (SYN, RST, FIN)
+   *
+   *   value is next state to change to
+   */
+  nat44_ed_tcp_state_e tcp_state_change_table[NAT44_ED_TCP_N_STATE]
+                                            [NAT44_ED_N_DIR]
+                                            [NAT44_ED_TCP_N_FLAG];
 } snat_main_t;
 
 typedef struct
@@ -785,16 +803,6 @@ nat44_ed_is_interface_outside (snat_interface_t *i)
   return i->flags & NAT_INTERFACE_FLAG_IS_OUTSIDE;
 }
 
-/** \brief Check if NAT44 endpoint-dependent TCP session is closed.
-    @param s NAT session
-    @return true if session is closed
-*/
-always_inline bool
-nat44_is_ses_closed (snat_session_t *s)
-{
-  return s->state == 0xf;
-}
-
 /** \brief Check if client initiating TCP connection (received SYN from client)
     @param t TCP header
     @return true if client initiating TCP connection
@@ -878,7 +886,7 @@ int nat44_ed_add_output_interface (u32 sw_if_index);
 int nat44_ed_del_output_interface (u32 sw_if_index);
 
 int nat44_ed_add_address (ip4_address_t *addr, u32 vrf_id, u8 twice_nat);
-int nat44_ed_del_address (ip4_address_t addr, u8 delete_sm, u8 twice_nat);
+int nat44_ed_del_address (ip4_address_t addr, u8 twice_nat);
 int nat44_ed_add_interface_address (u32 sw_if_index, u8 twice_nat);
 int nat44_ed_del_interface_address (u32 sw_if_index, u8 twice_nat);