Coding UDP Socket in C - sendto Invalid Arguments - sockets

Question

I'm actually back to programming in C, and I want to code a UDP Client.
My problem is that I'm having an error when executing the sendto function... getting errno : 22 and the message error : Invalid argument
char query[1024];
int querySize = strlen(query);
SOCKADDR_IN dest = { 0 };
int destSize = sizeof dest;
dest.sin_family = AF_INET;
dest.sin_addr.s_addr = inet_addr('192.168.0.3');
dest.sin_port = htons(6000);
sendto(sock, query, querySize, 0, (SOCKADDR *) &dest, destSize)
Hope someone could help me?
Here is my full code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#if defined (WIN32)
#include <winsock2.h>
typedef int socklen_t;
#elif defined (linux)
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define closesocket(param) close(param)
typedef int SOCKET;
typedef struct sockaddr_in SOCKADDR_IN;
typedef struct sockaddr SOCKADDR;
#endif
int main(int argc, char *argv[]) {
#if defined (WIN32)
WSADATA WSAData;
WSAStartup(MAKEWORD(2,2), &WSAData);
#endif
char source_ip[15] = "192.168.0.20";
int source_port = 5000;
char query[1024];
printf("- Opening Socket\n");
SOCKET sock;
sock = socket(AF_INET, SOCK_DGRAM, 0);
if(sock == INVALID_SOCKET) {
perror("[ERROR] socket()");
exit(errno);
}
printf("- Configuring socket source to : [%s:%d]\n", source_ip, source_port);
SOCKADDR_IN source;
source.sin_family = AF_INET;
source.sin_addr.s_addr = inet_addr(source_ip);
source.sin_port = htons(source_port);
if(bind(sock, (SOCKADDR *)&source, sizeof(source)) == SOCKET_ERROR) {
perror("[ERROR] bind()");
exit(errno);
}
int querySize = strlen(query);
SOCKADDR_IN dest = { 0 };
int destSize = sizeof dest;
dest.sin_family = AF_INET;
printf("- Sending packets\n");
dest.sin_addr.s_addr = inet_addr('192.168.0.3');
dest.sin_port = htons(6000);
if(sendto(sock, query, querySize, 0, (SOCKADDR *) &dest, destSize) < 0) {
perror("[ERROR] sendto()");
printf("%d\n", errno);
exit(errno);
}
printf("\n\n##############################\n");
printf("Closing socket ...\n");
closesocket(sock);
#if defined (WIN32)
WSACleanup();
#endif
printf("Program finished.\n");
return 0;
}

Answer 1

Did you notice,
that query is not being initialized?
So strlen(query) might result in a "very long" buffer.
That would be a good candidate for an EINVAL.