i am trying to make a program where i have a server with multiple clients, where a client sends a message to the server and when the server replies to it, the server broadcasts the reply to all the clients.
the code has some error and is not working.
i turned off my firewall. it is still not helping.
the code for my program is:
server:
#include <stdio.h> /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket() and bind() */
#include <arpa/inet.h> /* for sockaddr_in */
#include <stdlib.h> /* for atoi() and exit() */
#include <string.h> /* for memset() */
#include <unistd.h> /* for close() */
#include<sys/types.h>
#include<netdb.h>
#include<netinet/in.h>
void DieWithError(char *errorMessage); /* External error handling function */
void DieWithError(char *errorMessage)
{
perror(errorMessage);
exit(1);
}
int main(int argc, char *argv[])
{
int sock; /* Socket */
int s,n;
struct sockaddr_in broadcastAddr,client,server; /* Broadcast address */
char *broadcastIP,b1[100]; /* IP broadcast address */
unsigned short broadcastPort; /* Server port */
char *sendString; /* String to broadcast */
int broadcastPermission; /* Socket opt to set permission to broadcast */
unsigned int sendStringLen; /* Length of string to broadcast */
if (argc < 4) /* Test for correct number of parameters */
{
fprintf(stderr,"Usage: %s <IP Address> <Port> <Send String>\n", argv[0]);
exit(1);
}
broadcastIP = argv[1]; /* First arg: broadcast IP address */
broadcastPort = atoi(argv[2]); /* Second arg: broadcast port */
sendString = argv[3]; /* Third arg: string to broadcast */
/* Create socket for sending/receiving datagrams */
if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
DieWithError("socket() failed");
s=socket(AF_INET,SOCK_DGRAM,0);
server.sin_family=AF_INET;
server.sin_port=2000;
server.sin_addr.s_addr=inet_addr("127.0.0.1");
bind(s,(struct sockaddr *)&server,sizeof(server));
printf("\nServer ready,waiting for client....\n");
/* Set socket to allow broadcast */
broadcastPermission = 1;
if (setsockopt(sock, SOL_SOCKET, SO_BROADCAST, (void *) &broadcastPermission,sizeof(broadcastPermission)) < 0)
DieWithError("setsockopt() failed");
/* Construct local address structure */
memset(&broadcastAddr, 0, sizeof(broadcastAddr)); /* Zero out structure */
broadcastAddr.sin_family = AF_INET; /* Internet address family */
broadcastAddr.sin_addr.s_addr = inet_addr(broadcastIP);/* Broadcast IP address */
broadcastAddr.sin_port = htons(broadcastPort); /* Broadcast port */
int conn;
while(1)
{ unsigned int size = sizeof (client);
printf("About recv a datagram\n");
n=sizeof(client);
recvfrom(s,b1,sizeof(b1),0,(struct sockaddr *) &client,&n);
conn=accept(s, (struct sockaddr *) &client, &size);
read(conn, b1, sizeof(b1) - 1);
printf("the client sent:: %s \n",b1);
printf("the code after displaying client side!\n\n");
printf("ur brooadcast msg:: ");
scanf("%s",sendString);
sendStringLen = strlen(sendString); /* Find length of sendString */
printf("the expected string length is %d", sendStringLen);
/* Broadcast sendString in datagram to clients every 3 seconds*/
sendto(sock, sendString, sendStringLen, 0, (struct sockaddr *)&broadcastAddr, sizeof(broadcastAddr));
// DieWithError("sendto() sent a different number of bytes than expected ");
sleep(3); /* Avoids flooding the network */
}
/* NOT REACHED */
}
the code for client is:
#include <stdio.h> /* for printf() and fprintf() */
#include <sys/socket.h> /* for socket(), connect(), sendto(), and recvfrom() */
#include <arpa/inet.h> /* for sockaddr_in and inet_addr() */
#include <stdlib.h> /* for atoi() and exit() */
#include <string.h> /* for memset() */
#include <unistd.h> /* for close() */
#include<sys/types.h>
#include<netdb.h>
#include<netinet/in.h>
#define MAXRECVSTRING 255 /* Longest string to receive */
void DieWithError(char *errorMessage); /* External error handling function */
void DieWithError(char *errorMessage)
{
perror(errorMessage);
exit(1);
}
int main(int argc, char *argv[])
{
int sock; /* Socket */
int s,n;
char b2[100];
struct sockaddr_in broadcastAddr,client,server; /* Broadcast Address */
unsigned short broadcastPort; /* Port */
char recvString[MAXRECVSTRING+1]; /* Buffer for received string */
int recvStringLen; /* Length of received string */
if (argc != 2) /* Test for correct number of arguments */
{
fprintf(stderr,"Usage: %s <Broadcast Port>\n", argv[0]);
exit(1);
}
broadcastPort = atoi(argv[1]); /* First arg: broadcast port */
/* Create a best-effort datagram socket using UDP */
if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)
DieWithError("socket() failed");
s=socket(AF_INET,SOCK_DGRAM,0);
server.sin_family=AF_INET;
server.sin_port=2000;
server.sin_addr.s_addr=inet_addr("127.0.0.1");
/* Construct bind structure */
memset(&broadcastAddr, 0, sizeof(broadcastAddr)); /* Zero out structure */
broadcastAddr.sin_family = AF_INET; /* Internet address family */
broadcastAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming interface */
broadcastAddr.sin_port = htons(broadcastPort); /* Broadcast port */
/* Bind to the broadcast port */
if (bind(sock, (struct sockaddr *) &broadcastAddr, sizeof(broadcastAddr)) < 0)
DieWithError("bind() failed");
while(1)
{
n=sizeof(client);
printf("\nenter what u wanna send\n");
fflush(stdin);
fgets(b2, 20, stdin);
printf("the entered string is %s", b2);
sendto(s,b2,strlen(b2),0,(struct sockaddr *) &client,n);
printf("message sent\n");
/* Receive a single datagram from the server */
if ((recvStringLen = recvfrom(sock, recvString, MAXRECVSTRING, 0, NULL, 0)) < 0)
DieWithError("recvfrom() failed");
recvString[recvStringLen] = '\0';
printf("Received: %s\n", recvString); /* Print the received string */
}
close(sock);
exit(0);
}
kindly help me with making this code work.
thanks a lot.