Socket programming C - bind error - c

Question

I try to create a function to open a socket (i will have multiple socket in the future) called libf_build_udp_socket. But when it comes to bind i got the error cannot assign requested address and if i bypass this bind i got an error when sending a cmd.
If i don't use my function and integrate directly the code in my main, it works perfectly.
For the explanation i have a computer under linux that have to send cmd and received log from different equipment such as signal receiver...
Here is my full code, so maybe you will better understand my goals.
/* Standard Linux headers */
#include <stdio.h> //printf
#include <string.h> //memset
#include <stdlib.h> //exit(0);
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/times.h>
#include <unistd.h>
#include <errno.h>
/* DEFINE */
#define IP_RX "192.168.0.10" //notre IP=192.168.0.5
#define BUFFLEN 1024 //Max length of buffer
#define PORT_RX 3000 //The port on which to send data
unsigned short int libf_build_udp_socket(int * udp_socket, char * server_address, unsigned short int udp_port);
int main (void)
{
/*
** Definition of the local variables.
*/
//SOCKET
struct sockaddr_in addr_rx;
int serv_len_rx=sizeof(addr_rx);
int socket_fd_rx;
unsigned short int socketStatus; /* Socket return status */
//FD
fd_set readfds;
//BUFFER & CMD
char recepbuff[BUFFLEN];
char cmd[BUFFLEN], cmd_final[BUFFLEN];
//OTHER
int i, recv;
char choice;
int loop=1;
//TIMEOUT STRUCT
struct timeval tv;
tv.tv_sec=0; /*timeout de 0sec*/
tv.tv_usec=1000; //NE MARCHE PAS SI =0
/*
** Initialisation of the local variables.
*/
memset(recepbuff, '0' ,sizeof(recepbuff)); /*pareil que bzero*/
i=0;
/*
** Creating the socket
** call socket (it creates an endpoint for communication and
** returns the socket descriptor.
** To create an UDP socket here are the param
** The protocol family should be AF_INET
** The protocol type is SOCK_DGRAM
** The protocol should beset to default ie
** DEF_PROTOCOL wich is default so 0. );
*/
//OPENING AND SETTING SOCKET RX
socketStatus = libf_build_udp_socket(&socket_fd_rx, IP_RX, PORT_RX);
if (socketStatus>0)
{
printf("Could not create the socket, code error %d\n", socketStatus);
return 0;
}
/* Messaging*/
while(1)
{
printf ("\n//Boucle %d\n", i);
//clear the buffer by filling null, it might have previously received data
memset(recepbuff, '\0' ,sizeof(recepbuff));
loop=1;
//preparing cmd
printf("Enter command :");
fgets(cmd, sizeof(cmd) , stdin);
snprintf(cmd_final, sizeof (cmd_final), cmd, "\r\n"); /*adding 0d 0a to the cmd*/
//send cmd
if ( (sendto(socket_fd_rx , cmd_final, BUFFLEN , 0 , (struct sockaddr *)&addr_rx, serv_len_rx) ) < 0 )
{
perror("ERROR > send cmd failed to wass : ");
return 0;
}
else
{
printf( "cmd send to %s:%d\n" ,inet_ntoa(addr_rx.sin_addr), ntohs(addr_rx.sin_port) );
}
//printf("\n... waiting answer from %s:%d ... \n" ,inet_ntoa(addr_rx.sin_addr), ntohs(addr_rx.sin_port) );
//strcpy(recepbuff, "whileloop");
//try to receive some data, this is a blocking call
while(loop)
{
memset(recepbuff, '\0' ,sizeof(recepbuff)); //empty buffer
FD_ZERO(&readfds);
FD_SET(socket_fd_rx, &readfds); //set testing for rx
select(socket_fd_rx+1, &readfds, NULL, NULL, &tv); //block until cmd becomes available
if(FD_ISSET(socket_fd_rx, &readfds)) //input rx available
{
//printf("Data to be read \n");
recvfrom( socket_fd_rx, recepbuff , BUFFLEN, 0, (struct sockaddr *)&addr_rx, &serv_len_rx); //recep
printf("[=> Réponse : %s\n", recepbuff);
}
else
{
loop=0;
}
}
printf(".... Réponse done from %s:%d .... \n",inet_ntoa(addr_rx.sin_addr),ntohs(addr_rx.sin_port) );
i++;
}
close(socket_fd_rx);
return 0;
}
//FONCTIONS
//OPENING 1 SETTING A SOCKET
/** libf_build_udp_socket
*
* This function creates an UDP socket.
*
* \param udp_socket socket identifier
* \param server_address IP destination address
* \param udp_port Destination UDP port
* \param server_flag TRUE to bind socket on UDP port
*
* \return 0 if successful; error code otherwise
*/
unsigned short int libf_build_udp_socket(int * udp_socket, char * server_address, unsigned short int udp_port)
{
/*
** Defining of the local variables.
*/
struct sockaddr_in serv_addr; /* Server Socket address structure*/
short int status = 0; /* internal status return*/
unsigned short int return_status = 0; /* the returnes status value */
/*
** creating the socket ;
** call socket (it creates an endpoint for communication and
** returns the socket
** descriptor. To create an UDP socket
** the parameter family is set
** to AF_INET, the type to SOCK_DGRAM, and
** the protocol to
** DEF_PROTOCOL. The socket is a global variable.);
*/
*udp_socket = socket(AF_INET, SOCK_DGRAM, 0);
if (*udp_socket < 0)
{
return_status = 1;
}
else
{
status = 1; //for future check
if (status >= 0)
{
/*
** reset the serv_addr variable
*/
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
/*
** set the sockname.sin_addr.s_addr to server address;
** sockname.sin_addr.s_addr = htonl(server address);
** set the sockname field sockname.sin_port to the used port number;
** sockname.sin_port = htons (udp port);
*/
serv_addr.sin_addr.s_addr = inet_addr(server_address);
serv_addr.sin_port = htons(udp_port);
/*
** Bind this socket to a name;
** call bind (it assigns a name or address to an unnamed socket.
** When a socket is created with socket it exists in
** a name space (address family) but has no name assigned.
** The bind requests the name, be assigned to the socket);
** If (return status signal an error)
** {
** set to return variable to error
** }
*/
status = bind(*udp_socket, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
if (status < 0)
{
printf("bind failed with %s", strerror(errno));
return_status = 2;
}
}
else
{
return_status = 3;
}
}
/*
** return status;
*/
return return_status;
}
Maybe i'm missing something essential in socket programming, i made a lot of research and try different things but it still doesn't want to work ! I would appreciate some help ! Thank you !