freewtp/src/wtp/wtp_dfa.c

542 lines
15 KiB
C

#include "wtp.h"
#include "wtp_dfa.h"
#include "capwap_array.h"
#include "capwap_dfa.h"
#include "capwap_dtls.h"
#include "wtp_radio.h"
#include <signal.h>
#define WTP_RECV_NOERROR_RADIO -1001
/* Handler signal */
static void wtp_signal_handler(int signum) {
if ((signum == SIGINT) || (signum == SIGTERM)) {
g_wtp.running = 0;
}
}
/* */
static struct capwap_packet_rxmng* wtp_get_packet_rxmng(void) {
if (!g_wtp.rxmngpacket) {
g_wtp.rxmngpacket = capwap_packet_rxmng_create_message();
}
return g_wtp.rxmngpacket;
}
/* */
void wtp_free_packet_rxmng(void) {
if (g_wtp.rxmngpacket) {
capwap_packet_rxmng_free(g_wtp.rxmngpacket);
g_wtp.rxmngpacket = NULL;
}
}
/* */
static void wtp_send_invalid_request(struct capwap_packet_rxmng* rxmngpacket, uint32_t errorcode) {
struct capwap_header_data capwapheader;
struct capwap_packet_txmng* txmngpacket;
struct capwap_list* responsefragmentpacket;
struct capwap_fragment_packet_item* packet;
struct capwap_header* header;
struct capwap_resultcode_element resultcode = { .code = errorcode };
ASSERT(rxmngpacket != NULL);
ASSERT(rxmngpacket->fragmentlist->first != NULL);
/* */
packet = (struct capwap_fragment_packet_item*)rxmngpacket->fragmentlist->first->item;
header = (struct capwap_header*)packet->buffer;
/* Odd message type */
capwap_header_init(&capwapheader, CAPWAP_RADIOID_NONE, GET_WBID_HEADER(header));
txmngpacket = capwap_packet_txmng_create_ctrl_message(&capwapheader, rxmngpacket->ctrlmsg.type + 1, rxmngpacket->ctrlmsg.seq, g_wtp.mtu);
/* Add message element */
capwap_packet_txmng_add_message_element(txmngpacket, CAPWAP_ELEMENT_RESULTCODE, &resultcode);
/* Unknown response complete, get fragment packets */
responsefragmentpacket = capwap_list_create();
capwap_packet_txmng_get_fragment_packets(txmngpacket, responsefragmentpacket, g_wtp.fragmentid);
if (responsefragmentpacket->count > 1) {
g_wtp.fragmentid++;
}
/* Free packets manager */
capwap_packet_txmng_free(txmngpacket);
/* Send unknown response */
capwap_crypt_sendto_fragmentpacket(&g_wtp.dtls, responsefragmentpacket);
/* Don't buffering a packets sent */
capwap_list_free(responsefragmentpacket);
}
/* WTP Execute state */
static void wtp_dfa_execute(struct capwap_parsed_packet* packet) {
ASSERT(packet != NULL);
switch (g_wtp.state) {
case CAPWAP_DISCOVERY_STATE: {
wtp_dfa_state_discovery(packet);
break;
}
case CAPWAP_SULKING_STATE: {
wtp_dfa_state_sulking(packet);
break;
}
case CAPWAP_DTLS_CONNECT_STATE: {
wtp_teardown_connection();
break;
}
case CAPWAP_DTLS_TEARDOWN_STATE: {
wtp_dfa_state_dtlsteardown(packet);
break;
}
case CAPWAP_JOIN_STATE: {
wtp_dfa_state_join(packet);
break;
}
case CAPWAP_CONFIGURE_STATE: {
wtp_dfa_state_configure(packet);
break;
}
case CAPWAP_DATA_CHECK_STATE: {
wtp_dfa_state_datacheck(packet);
break;
}
case CAPWAP_RUN_STATE: {
wtp_dfa_state_run(packet);
break;
}
default: {
capwap_logging_debug("Unknown action event: %lu", g_wtp.state);
break;
}
}
}
/* */
static int wtp_recvfrom(struct wtp_fds* fds, void* buffer, int* size, union sockaddr_capwap* recvfromaddr, union sockaddr_capwap* recvtoaddr) {
int index;
ASSERT(fds != NULL);
ASSERT(fds->fdspoll != NULL);
ASSERT(fds->fdstotalcount > 0);
ASSERT(buffer != NULL);
ASSERT(size != NULL);
ASSERT(*size > 0);
ASSERT(recvfromaddr != NULL);
ASSERT(recvtoaddr != NULL);
/* Wait packet */
index = capwap_wait_recvready(fds->fdspoll, fds->fdstotalcount, g_wtp.timeout);
if (index < 0) {
return index;
} else if ((fds->wifieventsstartpos >= 0) && (index >= fds->wifieventsstartpos)) {
int pos = index - fds->wifieventsstartpos;
if (pos < fds->wifieventscount) {
if (!fds->wifievents[pos].event_handler) {
return CAPWAP_RECV_ERROR_SOCKET;
}
fds->wifievents[pos].event_handler(fds->fdspoll[index].fd, fds->wifievents[pos].params, fds->wifievents[pos].paramscount);
}
return WTP_RECV_NOERROR_RADIO;
} else if ((fds->kmodeventsstartpos >= 0) && (index >= fds->kmodeventsstartpos)) {
int pos = index - fds->kmodeventsstartpos;
if (pos < fds->kmodeventscount) {
if (!fds->kmodevents[pos].event_handler) {
return CAPWAP_RECV_ERROR_SOCKET;
}
fds->kmodevents[pos].event_handler(fds->fdspoll[index].fd, fds->kmodevents[pos].params, fds->kmodevents[pos].paramscount);
}
return WTP_RECV_NOERROR_RADIO;
}
/* Receive packet */
if (capwap_recvfrom(fds->fdspoll[index].fd, buffer, size, recvfromaddr, recvtoaddr)) {
return CAPWAP_RECV_ERROR_SOCKET;
}
return index;
}
/* */
static int wtp_dfa_init_fdspool(struct wtp_fds* fds, struct capwap_network* net) {
ASSERT(fds != NULL);
ASSERT(net != NULL);
/* */
memset(fds, 0, sizeof(struct wtp_fds));
fds->fdsnetworkcount = capwap_network_set_pollfd(net, NULL, 0);
fds->fdspoll = (struct pollfd*)capwap_alloc(sizeof(struct pollfd) * fds->fdsnetworkcount);
/* Retrive all socket for polling */
fds->fdstotalcount = capwap_network_set_pollfd(net, fds->fdspoll, fds->fdsnetworkcount);
if (fds->fdsnetworkcount != fds->fdstotalcount) {
capwap_free(fds->fdspoll);
return -1;
}
/* Update Event File Descriptor */
wtp_dfa_update_fdspool(fds);
return 0;
}
/* */
int wtp_dfa_update_fdspool(struct wtp_fds* fds) {
int totalcount;
int kmodcount;
int wificount;
struct pollfd* fdsbuffer;
ASSERT(fds != NULL);
/* Retrieve number of Dynamic File Descriptor Event */
kmodcount = wtp_kmod_getfd(NULL, NULL, 0);
wificount = wifi_event_getfd(NULL, NULL, 0);
if ((kmodcount < 0) || (wificount < 0)) {
return -1;
}
/* Kernel Module Events Callback */
fds->kmodeventsstartpos = -1;
if (kmodcount != fds->kmodeventscount) {
if (fds->kmodevents) {
capwap_free(fds->kmodevents);
}
/* */
fds->kmodeventscount = kmodcount;
fds->kmodevents = (struct wtp_kmod_event*)((kmodcount > 0) ? capwap_alloc(sizeof(struct wtp_kmod_event) * kmodcount) : NULL);
}
/* Wifi Events Callback */
fds->wifieventsstartpos = -1;
if (wificount != fds->wifieventscount) {
if (fds->wifievents) {
capwap_free(fds->wifievents);
}
/* */
fds->wifieventscount = wificount;
fds->wifievents = (struct wifi_event*)((wificount > 0) ? capwap_alloc(sizeof(struct wifi_event) * wificount) : NULL);
}
/* Resize poll */
totalcount = fds->fdsnetworkcount + fds->kmodeventscount + fds->wifieventscount;
if (fds->fdstotalcount != totalcount) {
fdsbuffer = (struct pollfd*)capwap_alloc(sizeof(struct pollfd) * totalcount);
if (fds->fdspoll) {
if (fds->fdsnetworkcount > 0) {
memcpy(fdsbuffer, fds->fdspoll, sizeof(struct pollfd) * fds->fdsnetworkcount);
}
capwap_free(fds->fdspoll);
}
/* */
fds->fdspoll = fdsbuffer;
fds->fdstotalcount = totalcount;
}
/* Retrieve File Descriptor Kernel Module Event */
if (fds->kmodeventscount > 0) {
fds->kmodeventsstartpos = fds->fdsnetworkcount;
wtp_kmod_getfd(&fds->fdspoll[fds->kmodeventsstartpos], fds->kmodevents, fds->kmodeventscount);
}
/* Retrieve File Descriptor Wifi Event */
if (fds->wifieventscount > 0) {
fds->wifieventsstartpos = fds->fdsnetworkcount + fds->kmodeventscount;
wifi_event_getfd(&fds->fdspoll[fds->wifieventsstartpos], fds->wifievents, fds->wifieventscount);
}
return fds->fdstotalcount;
}
/* */
void wtp_dfa_free_fdspool(struct wtp_fds* fds) {
ASSERT(fds != NULL);
if (fds->fdspoll) {
capwap_free(fds->fdspoll);
}
if (fds->kmodevents) {
capwap_free(fds->kmodevents);
}
if (fds->wifievents) {
capwap_free(fds->wifievents);
}
}
/* */
static void wtp_dfa_closeapp(void) {
g_wtp.running = 0;
/* Teardown */
wtp_teardown_connection();
/* Wait RFC teardown timeout */
for (;;) {
if (capwap_timeout_wait(capwap_timeout_getcoming(g_wtp.timeout)) < 0) {
break;
}
if (capwap_timeout_hasexpired(g_wtp.timeout) == g_wtp.idtimercontrol) {
break;
}
}
/* */
ASSERT(g_wtp.state == CAPWAP_DEAD_STATE);
}
/* WTP state machine */
int wtp_dfa_running(void) {
int res;
int result = CAPWAP_SUCCESSFUL;
char bufferencrypt[CAPWAP_MAX_PACKET_SIZE];
char bufferplain[CAPWAP_MAX_PACKET_SIZE];
char* buffer;
int buffersize;
struct capwap_parsed_packet packet;
int index;
union sockaddr_capwap fromaddr;
union sockaddr_capwap toaddr;
/* Init */
memset(&packet, 0, sizeof(struct capwap_parsed_packet));
/* Configure poll struct */
if (wtp_dfa_init_fdspool(&g_wtp.fds, &g_wtp.net)) {
return CAPWAP_GENERIC_ERROR;
}
/* Handler signal */
g_wtp.running = 1;
signal(SIGPIPE, SIG_IGN);
signal(SIGINT, wtp_signal_handler);
signal(SIGTERM, wtp_signal_handler);
/* Init complete, start DFA */
wtp_dfa_change_state(CAPWAP_IDLE_STATE);
wtp_dfa_state_idle();
/* */
while (g_wtp.state != CAPWAP_DEAD_STATE) {
/* If request wait packet from AC */
buffer = bufferencrypt;
buffersize = CAPWAP_MAX_PACKET_SIZE;
index = wtp_recvfrom(&g_wtp.fds, buffer, &buffersize, &fromaddr, &toaddr);
if (!g_wtp.running) {
capwap_logging_debug("Closing WTP, Teardown connection");
wtp_dfa_closeapp();
break;
} else if (index >= 0) {
if (g_wtp.teardown) {
continue; /* Drop packet */
} else {
int check;
/* Check source */
if (capwap_compare_ip(&g_wtp.dtls.peeraddr, &fromaddr)) {
continue; /* Unknown source */
}
/* Check of packet */
check = capwap_sanity_check(g_wtp.state, buffer, buffersize, g_wtp.dtls.enable);
if (check == CAPWAP_DTLS_PACKET) {
int oldaction = g_wtp.dtls.action;
/* Decrypt packet */
buffersize = capwap_decrypt_packet(&g_wtp.dtls, buffer, buffersize, bufferplain, CAPWAP_MAX_PACKET_SIZE);
if (buffersize > 0) {
buffer = bufferplain;
check = CAPWAP_PLAIN_PACKET;
} else if (buffersize == CAPWAP_ERROR_AGAIN) {
/* Check is handshake complete */
if ((oldaction == CAPWAP_DTLS_ACTION_HANDSHAKE) && (g_wtp.dtls.action == CAPWAP_DTLS_ACTION_DATA)) {
if (g_wtp.state == CAPWAP_DTLS_CONNECT_STATE) {
check = CAPWAP_NONE_PACKET;
wtp_send_join();
} else {
check = CAPWAP_WRONG_PACKET;
wtp_teardown_connection();
}
}
continue; /* Next packet */
} else {
if ((oldaction == CAPWAP_DTLS_ACTION_DATA) && (g_wtp.dtls.action == CAPWAP_DTLS_ACTION_SHUTDOWN)) {
wtp_teardown_connection();
}
continue; /* Next packet */
}
} else if (check == CAPWAP_WRONG_PACKET) {
capwap_logging_debug("Warning: sanity check failure");
/* Drop packet */
continue;
}
/* */
if (check == CAPWAP_PLAIN_PACKET) {
struct capwap_packet_rxmng* rxmngpacket;
/* Defragment management */
rxmngpacket = wtp_get_packet_rxmng();
/* If request, defragmentation packet */
check = capwap_packet_rxmng_add_recv_packet(rxmngpacket, buffer, buffersize);
if (check == CAPWAP_REQUEST_MORE_FRAGMENT) {
continue;
} else if (check != CAPWAP_RECEIVE_COMPLETE_PACKET) {
/* Discard fragments */
wtp_free_packet_rxmng();
continue;
}
/* Check for already response to packet */
if (capwap_is_request_type(rxmngpacket->ctrlmsg.type) && (g_wtp.remotetype == rxmngpacket->ctrlmsg.type) && (g_wtp.remoteseqnumber == rxmngpacket->ctrlmsg.seq)) {
/* Retransmit response */
if (!capwap_crypt_sendto_fragmentpacket(&g_wtp.dtls, g_wtp.responsefragmentpacket)) {
capwap_logging_error("Error to resend response packet");
} else {
capwap_logging_debug("Retrasmitted control packet");
}
continue;
}
/* Check message type */
res = capwap_check_message_type(rxmngpacket);
if (res != VALID_MESSAGE_TYPE) {
if (res == INVALID_REQUEST_MESSAGE_TYPE) {
capwap_logging_warning("Unexpected Unrecognized Request, send Response Packet with error");
wtp_send_invalid_request(rxmngpacket, CAPWAP_RESULTCODE_MSG_UNEXPECTED_UNRECOGNIZED_REQUEST);
}
capwap_logging_debug("Invalid message type");
wtp_free_packet_rxmng();
continue;
}
/* Parsing packet */
res = capwap_parsing_packet(rxmngpacket, &packet);
if (res != PARSING_COMPLETE) {
if ((res == UNRECOGNIZED_MESSAGE_ELEMENT) && capwap_is_request_type(rxmngpacket->ctrlmsg.type)) {
capwap_logging_warning("Unrecognized Message Element, send Response Packet with error");
wtp_send_invalid_request(rxmngpacket, CAPWAP_RESULTCODE_FAILURE_UNRECOGNIZED_MESSAGE_ELEMENT);
/* TODO: add the unrecognized message element */
}
/* */
capwap_free_parsed_packet(&packet);
wtp_free_packet_rxmng();
capwap_logging_debug("Failed parsing packet");
continue;
}
/* Validate packet */
if (capwap_validate_parsed_packet(&packet, NULL)) {
if (capwap_is_request_type(rxmngpacket->ctrlmsg.type)) {
capwap_logging_warning("Missing Mandatory Message Element, send Response Packet with error");
wtp_send_invalid_request(rxmngpacket, CAPWAP_RESULTCODE_FAILURE_MISSING_MANDATORY_MSG_ELEMENT);
}
/* */
capwap_free_parsed_packet(&packet);
wtp_free_packet_rxmng();
capwap_logging_debug("Failed validation parsed packet");
continue;
}
/* Receive a complete packet */
wtp_dfa_execute(&packet);
/* Free packet */
capwap_free_parsed_packet(&packet);
wtp_free_packet_rxmng();
}
}
} else if ((index == CAPWAP_RECV_ERROR_INTR) || (index == WTP_RECV_NOERROR_RADIO)) {
/* Ignore recv */
continue;
} else if (index == CAPWAP_RECV_ERROR_SOCKET) {
/* Socket close */
break;
}
}
/* Free memory */
wtp_dfa_free_fdspool(&g_wtp.fds);
return result;
}
/* Change WTP state machine */
void wtp_dfa_change_state(int state) {
if (state != g_wtp.state) {
capwap_logging_debug("WTP change state from %s to %s", capwap_dfa_getname(g_wtp.state), capwap_dfa_getname(state));
g_wtp.state = state;
}
}
/* */
void wtp_free_reference_last_request(void) {
capwap_list_flush(g_wtp.requestfragmentpacket);
}
/* */
void wtp_free_reference_last_response(void) {
capwap_list_flush(g_wtp.responsefragmentpacket);
g_wtp.remotetype = 0;
g_wtp.remoteseqnumber = 0;
}
/* */
void wtp_dfa_retransmition_timeout(struct capwap_timeout* timeout, unsigned long index, void* context, void* param) {
if (!g_wtp.requestfragmentpacket->count) {
capwap_logging_warning("Invalid retransmition request packet");
wtp_teardown_connection();
} else {
g_wtp.retransmitcount++;
if (g_wtp.retransmitcount >= WTP_MAX_RETRANSMIT) {
capwap_logging_info("Retransmition request packet timeout");
/* Timeout state */
wtp_free_reference_last_request();
wtp_teardown_connection();
} else {
/* Retransmit request */
capwap_logging_debug("Retransmition request packet");
if (!capwap_crypt_sendto_fragmentpacket(&g_wtp.dtls, g_wtp.requestfragmentpacket)) {
capwap_logging_error("Error to send request packet");
}
/* Update timeout */
capwap_timeout_set(g_wtp.timeout, g_wtp.idtimercontrol, WTP_RETRANSMIT_INTERVAL, wtp_dfa_retransmition_timeout, NULL, NULL);
}
}
}