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#include <stdio.h>
#include <assert.h>
#include "log_internal.h"
#include "session_internal.h"
#include "session_transition.h"
#define SESSION_TRANSITION_LOG_INFO(format, ...) STELLAR_LOG_INFO(__thread_local_logger, "session transition", format, ##__VA_ARGS__)
#define MAX_TRANSITION_PER_STATE 8
struct session_transition
{
int inputs_mask;
enum session_state next_state;
} fsm[MAX_STATE][MAX_TRANSITION_PER_STATE];
/*
* session transition
*
* SESSION_STATE_INIT -> SESSION_STATE_INIT ( NONE )
* SESSION_STATE_INIT -> SESSION_STATE_OPENING ( TCP_SYN | TCP_SYN_ACK | UDP_DATA )
*
* SESSION_STATE_OPENING -> SESSION_STATE_OPENING ( NONE )
* 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_DISCARD ( USER_CLOSE )
* SESSION_STATE_OPENING -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT )
*
* SESSION_STATE_ACTIVE -> SESSION_STATE_ACTIVE ( NONE )
* SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSING ( TCP_FIN | TCP_RST | TIMEOUT )
* SESSION_STATE_ACTIVE -> SESSION_STATE_DISCARD ( USER_CLOSE )
* SESSION_STATE_ACTIVE -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT)
*
* SESSION_STATE_CLOSING -> SESSION_STATE_CLOSING ( NONE )
* SESSION_STATE_CLOSING -> SESSION_STATE_DISCARD ( USER_CLOSE )
* SESSION_STATE_CLOSING -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT )
*
* SESSION_STATE_DISCARD -> SESSION_STATE_DISCARD ( NONE )
* SESSION_STATE_DISCARD -> SESSION_STATE_CLOSED ( LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT )
*/
static void session_inputs_to_str(int inputs, char *buff, int len)
{
int nused = 0;
if (inputs & TCP_SYN)
{
nused += snprintf(buff + nused, len - nused, "TCP_SYN");
}
if (inputs & TCP_SYN_ACK)
{
nused += snprintf(buff + nused, len - nused, "TCP_SYN_ACK");
}
if (inputs & TCP_FIN)
{
nused += snprintf(buff + nused, len - nused, "TCP_FIN");
}
if (inputs & TCP_RST)
{
nused += snprintf(buff + nused, len - nused, "TCP_RST");
}
if (inputs & TCP_DATA)
{
nused += snprintf(buff + nused, len - nused, "TCP_DATA");
}
if (inputs & UDP_DATA)
{
nused += snprintf(buff + nused, len - nused, "UDP_DATA");
}
if (inputs & TIMEOUT)
{
nused += snprintf(buff + nused, len - nused, "TIMEOUT");
}
if (inputs & LRU_EVICT)
{
nused += snprintf(buff + nused, len - nused, "LRU_EVICT");
}
if (inputs & PORT_REUSE_EVICT)
{
nused += snprintf(buff + nused, len - nused, "PORT_REUSE_EVICT");
}
if (inputs & USER_CLOSE)
{
nused += snprintf(buff + nused, len - nused, "USER_CLOSE");
}
}
void session_transition_init()
{
fsm[SESSION_STATE_INIT][0].inputs_mask = TCP_SYN | TCP_SYN_ACK | UDP_DATA;
fsm[SESSION_STATE_INIT][0].next_state = SESSION_STATE_OPENING;
fsm[SESSION_STATE_INIT][1].inputs_mask = NONE;
fsm[SESSION_STATE_INIT][1].next_state = SESSION_STATE_INIT;
fsm[SESSION_STATE_OPENING][0].inputs_mask = TCP_DATA | UDP_DATA;
fsm[SESSION_STATE_OPENING][0].next_state = SESSION_STATE_ACTIVE;
fsm[SESSION_STATE_OPENING][1].inputs_mask = TCP_FIN | TCP_RST | TIMEOUT;
fsm[SESSION_STATE_OPENING][1].next_state = SESSION_STATE_CLOSING;
fsm[SESSION_STATE_OPENING][2].inputs_mask = USER_CLOSE;
fsm[SESSION_STATE_OPENING][2].next_state = SESSION_STATE_DISCARD;
fsm[SESSION_STATE_OPENING][3].inputs_mask = LRU_EVICT | PORT_REUSE_EVICT;
fsm[SESSION_STATE_OPENING][3].next_state = SESSION_STATE_CLOSED;
fsm[SESSION_STATE_OPENING][4].inputs_mask = NONE;
fsm[SESSION_STATE_OPENING][4].next_state = SESSION_STATE_OPENING;
fsm[SESSION_STATE_ACTIVE][0].inputs_mask = TCP_FIN | TCP_RST | TIMEOUT;
fsm[SESSION_STATE_ACTIVE][0].next_state = SESSION_STATE_CLOSING;
fsm[SESSION_STATE_ACTIVE][1].inputs_mask = USER_CLOSE;
fsm[SESSION_STATE_ACTIVE][1].next_state = SESSION_STATE_DISCARD;
fsm[SESSION_STATE_ACTIVE][2].inputs_mask = LRU_EVICT | PORT_REUSE_EVICT;
fsm[SESSION_STATE_ACTIVE][2].next_state = SESSION_STATE_CLOSED;
fsm[SESSION_STATE_ACTIVE][3].inputs_mask = NONE;
fsm[SESSION_STATE_ACTIVE][3].next_state = SESSION_STATE_ACTIVE;
fsm[SESSION_STATE_CLOSING][0].inputs_mask = USER_CLOSE;
fsm[SESSION_STATE_CLOSING][0].next_state = SESSION_STATE_DISCARD;
fsm[SESSION_STATE_CLOSING][1].inputs_mask = LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT;
fsm[SESSION_STATE_CLOSING][1].next_state = SESSION_STATE_CLOSED;
fsm[SESSION_STATE_CLOSING][2].inputs_mask = NONE;
fsm[SESSION_STATE_CLOSING][2].next_state = SESSION_STATE_CLOSING;
fsm[SESSION_STATE_DISCARD][0].inputs_mask = LRU_EVICT | PORT_REUSE_EVICT | TIMEOUT;
fsm[SESSION_STATE_DISCARD][0].next_state = SESSION_STATE_CLOSED;
fsm[SESSION_STATE_DISCARD][1].inputs_mask = NONE;
fsm[SESSION_STATE_DISCARD][1].next_state = SESSION_STATE_DISCARD;
}
enum session_state session_transition_run(enum session_state curr_state, int inputs)
{
struct session_transition *list = fsm[curr_state];
for (int i = 0; i < MAX_TRANSITION_PER_STATE; i++)
{
int mask = list[i].inputs_mask;
if (mask & inputs)
{
return list[i].next_state;
}
if (mask == NONE)
{
return list[i].next_state;
}
}
assert(0);
return curr_state;
}
void session_transition_log(struct session *sess, enum session_state curr_state, enum session_state next_state, int inputs)
{
if (curr_state == next_state)
{
return;
}
char reason[128] = {0};
session_inputs_to_str(inputs, reason, sizeof(reason));
SESSION_TRANSITION_LOG_INFO("%s session %lu %s (%s) %s -> %s",
session_type_to_str(session_get_type(sess)),
session_get_id(sess), session_get_readable_addr(sess), reason,
session_state_to_str(curr_state), session_state_to_str(next_state));
}
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