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Add connect_to socket
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@Jakio815
Jakio815 committed Dec 17, 2024
1 parent b82c3f0 commit a3c81de
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Showing 3 changed files with 60 additions and 76 deletions.
79 changes: 3 additions & 76 deletions core/federated/federate.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -936,42 +936,6 @@ static int perform_hmac_authentication() {
}
#endif

static void close_rti_socket() {
shutdown(_fed.socket_TCP_RTI, SHUT_RDWR);
close(_fed.socket_TCP_RTI);
_fed.socket_TCP_RTI = -1;
}

/**
* Return in the result a struct with the address info for the specified hostname and port.
* The memory for the result is dynamically allocated and must be freed using freeaddrinfo.
* @param hostname The host name.
* @param port The port number.
* @param result The struct into which to write.
*/
static void rti_address(const char* hostname, uint16_t port, struct addrinfo** result) {
struct addrinfo hints;

memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET; /* Allow IPv4 */
hints.ai_socktype = SOCK_STREAM; /* Stream socket */
hints.ai_protocol = IPPROTO_TCP; /* TCP protocol */
hints.ai_addr = NULL;
hints.ai_next = NULL;
hints.ai_flags = AI_NUMERICSERV; /* Allow only numeric port numbers */

// Convert port number to string.
char str[6];
sprintf(str, "%u", port);

// Get address structure matching hostname and hints criteria, and
// set port to the port number provided in str. There should only
// ever be one matching address structure, and we connect to that.
if (getaddrinfo(hostname, (const char*)&str, &hints, result)) {
lf_print_error_and_exit("No host for RTI matching given hostname: %s", hostname);
}
}

/**
* Send the specified timestamp to the RTI and wait for a response.
* The specified timestamp should be current physical time of the
Expand Down Expand Up @@ -1914,42 +1878,12 @@ void lf_connect_to_rti(const char* hostname, int port) {

// Create a socket
_fed.socket_TCP_RTI = create_real_time_tcp_socket_errexit();

int result = -1;
struct addrinfo* res = NULL;
if (connect_to_socket(_fed.socket_TCP_RTI, hostname, uport, port) < 0) {
lf_print_error_and_exit("Failed to connect() to RTI.");
}

instant_t start_connect = lf_time_physical();
while (!CHECK_TIMEOUT(start_connect, CONNECT_TIMEOUT) && !_lf_termination_executed) {
if (res != NULL) {
// This is a repeated attempt.
if (_fed.socket_TCP_RTI >= 0)
close_rti_socket();

lf_sleep(CONNECT_RETRY_INTERVAL);

// Create a new socket.
_fed.socket_TCP_RTI = create_real_time_tcp_socket_errexit();

if (port == 0) {
// Free previously allocated address info.
freeaddrinfo(res);
// Increment the port number.
uport++;
if (uport >= DEFAULT_PORT + MAX_NUM_PORT_ADDRESSES)
uport = DEFAULT_PORT;

// Reconstruct the address info.
rti_address(hostname, uport, &res);
}
lf_print("Trying RTI again on port %d.", uport);
} else {
// This is the first attempt.
rti_address(hostname, uport, &res);
}

result = connect(_fed.socket_TCP_RTI, res->ai_addr, res->ai_addrlen);
if (result < 0)
continue; // Connect failed.

// Have connected to an RTI, but not sure it's the right RTI.
// Send a MSG_TYPE_FED_IDS message and wait for a reply.
Expand All @@ -1962,7 +1896,6 @@ void lf_connect_to_rti(const char* hostname, int port) {
continue; // Try again with a new port.
} else {
// No point in trying again because it will be the same port.
close_rti_socket();
lf_print_error_and_exit("Authentication failed.");
}
}
Expand Down Expand Up @@ -2031,11 +1964,7 @@ void lf_connect_to_rti(const char* hostname, int port) {
continue;
}
}
if (result < 0) {
lf_print_error_and_exit("Failed to connect to RTI with timeout: " PRINTF_TIME, CONNECT_TIMEOUT);
}

freeaddrinfo(res); /* No longer needed */

// Call a generated (external) function that sends information
// about connections between this federate and other federates
Expand All @@ -2051,8 +1980,6 @@ void lf_connect_to_rti(const char* hostname, int port) {
encode_uint16(udp_port, &(UDP_port_number[1]));
write_to_socket_fail_on_error(&_fed.socket_TCP_RTI, 1 + sizeof(uint16_t), UDP_port_number, NULL,
"Failed to send the UDP port number to the RTI.");

lf_print("Connected to RTI at %s:%d.", hostname, uport);
}

void lf_create_server(int specified_port) {
Expand Down
55 changes: 55 additions & 0 deletions core/federated/network/socket_common.c
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Original file line number Diff line number Diff line change
Expand Up @@ -20,7 +20,11 @@
#include <netinet/in.h> // IPPROTO_TCP, IPPROTO_UDP
#include <netinet/tcp.h> // TCP_NODELAY
#include <errno.h>
#include <stdio.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdarg.h> //va_list
#include <string.h> // strerror

Expand Down Expand Up @@ -317,3 +321,54 @@ void write_to_socket_fail_on_error(int* socket, size_t num_bytes, unsigned char*
}
}
}

int connect_to_socket(int sock, const char* hostname, int port, uint16_t user_specified_port) {
struct addrinfo hints;
struct addrinfo* result;
int ret = -1;

memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET; /* Allow IPv4 */
hints.ai_socktype = SOCK_STREAM; /* Stream socket */
hints.ai_protocol = IPPROTO_TCP; /* TCP protocol */
hints.ai_addr = NULL;
hints.ai_next = NULL;
hints.ai_flags = AI_NUMERICSERV; /* Allow only numeric port numbers */

int used_port = (user_specified_port == 0) ? port : user_specified_port;

instant_t start_connect = lf_time_physical();
// while (!_lf_termination_executed) { // Not working...
while (1) {
if (CHECK_TIMEOUT(start_connect, CONNECT_TIMEOUT)) {
lf_print_error("Failed to connect with timeout: " PRINTF_TIME ". Giving up.", CONNECT_TIMEOUT);
break;
}
// Convert port number to string.
char str[6];
sprintf(str, "%u", used_port);

// Get address structure matching hostname and hints criteria, and
// set port to the port number provided in str. There should only
// ever be one matching address structure, and we connect to that.
if (getaddrinfo(hostname, (const char*)&str, &hints, &result)) {
lf_print_error("No host matching given hostname: %s", hostname);
break;
}
ret = connect(sock, result->ai_addr, result->ai_addrlen);
if (ret < 0) {
lf_sleep(CONNECT_RETRY_INTERVAL);
if (user_specified_port == 0) {
used_port++;
}
lf_print_warning("Could not connect. Will try again every " PRINTF_TIME " nanoseconds.\n",
CONNECT_RETRY_INTERVAL);
continue;
} else {
break;
}
freeaddrinfo(result);
}
lf_print("Connected to RTI at %s:%d.", hostname, used_port);
return ret;
}
2 changes: 2 additions & 0 deletions include/core/federated/network/socket_common.h
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Original file line number Diff line number Diff line change
Expand Up @@ -194,4 +194,6 @@ int write_to_socket_close_on_error(int* socket, size_t num_bytes, unsigned char*
void write_to_socket_fail_on_error(int* socket, size_t num_bytes, unsigned char* buffer, lf_mutex_t* mutex,
char* format, ...);

int connect_to_socket(int sock, const char* hostname, int port, uint16_t user_specified_port);

#endif /* SOCKET_COMMON_H */

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