Socket broadcasting

[rezamirani]

Dear Mr,

I wrote one sample socket in linux, it broadcast an character to all the machines in my subnet.
I set socket options in udp to broadcast then sendto() the client, but I couldn't receive any thing in client.
I checked my program with several programs, it's same.but I can't receive from broadcast.
What should I do ?

Thanks for you incoming helps.

[sicarie]

What did you write your program in?

Can you ping the machines from the computer your program is running on?

What programs did you "check yours against" and how did you check it?

Are you aware of the Networking definition of 'broadcast' and how that's different depending on your situation?

[rezamirani]

What did you write your program in?

Can you ping the machines from the computer your program is running on?

What programs did you "check yours against" and how did you check it?

Are you aware of the Networking definition of 'broadcast' and how that's different depending on your situation?

Dear Sicarie,
This is my program on both server and client side , please check and tell me more about Network definition od broad cast and different depending on my situation.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>Server Side>>>>>>>>>>>>>>>>>>>

  #include <stdio.h>
          #include <sys/socket.h>
          #include <arpa/inet.h>
          #include <stdlib.h>
          #include <string.h>
          #include <unistd.h>
          #include <netinet/in.h>
 
          #define BUFFSIZE 255
          void Die(char *mess) { perror(mess); exit(1); }
 
int main(int argc, char *argv[]) {
            int sock;
            struct sockaddr_in echoserver;
            struct sockaddr_in echoclient;
            char buffer[BUFFSIZE];
            unsigned int echolen, clientlen;
            int received = 0;
 
            if (argc != 4) {
              fprintf(stderr, "USAGE: %s <server_ip> <word> <port>\n", argv[0]);
              exit(1);
            }
            /* Create the UDP socket */
            if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
              Die("Failed to create socket");
            }
            /* Construct the server sockaddr_in structure */
            memset(&echoserver, 0, sizeof(echoserver));       /* Clear struct */
            echoserver.sin_family = AF_INET;                  /* Internet/IP */
            echoserver.sin_addr.s_addr = inet_addr(argv[1]);  /* IP address */
            echoserver.sin_port = htons(atoi(argv[3]));       /* server port */
 
/*Set socket option to broadcast*/
 int opt = 1;
 setsockopt(sock(), SOL_SOCKET, SO_BROADCAST, &opt, sizeof(int));
 
 /* Send the word to the server */
            echolen = strlen(argv[2]);
            if (sendto(sock, argv[2], echolen, 0,
                       (struct sockaddr *) &echoserver,
                       sizeof(echoserver)) != echolen) {
              Die("Mismatch in number of sent bytes");
            }
 
            close(sock);
            exit(0);

<<<<<<<<<<<<<<<<<<<<<in other side program >>>>>>>>>>>>>>>>>

#include <stdio.h>
          #include <sys/socket.h>
          #include <arpa/inet.h>
          #include <stdlib.h>
          #include <string.h>
          #include <unistd.h>
          #include <netinet/in.h>
 
          #define BUFFSIZE 255
          void Die(char *mess) { perror(mess); exit(1); }
 
int main(int argc, char *argv[]) {
            int sock;
            struct sockaddr_in echoserver;
            struct sockaddr_in echoclient;
            char buffer[BUFFSIZE];
            unsigned int echolen, clientlen, serverlen;
            int received = 0;
 
            if (argc != 2) {
              fprintf(stderr, "USAGE: %s <port>\n", argv[0]);
              exit(1);
            }
/* Create the UDP socket */
          if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
            Die("Failed to create socket");
          }
          /* Construct the server sockaddr_in structure */
          memset(&echoserver, 0, sizeof(echoserver));       /* Clear struct */
          echoserver.sin_family = AF_INET;                  /* Internet/IP */
          echoserver.sin_addr.s_addr = htonl(INADDR_ANY);   /* Any IP address */
          echoserver.sin_port = htons(atoi(argv[1]));       /* server port */
 
          /* Bind the socket */
          serverlen = sizeof(echoserver);
          if (bind(sock, (struct sockaddr *) &echoserver, serverlen) < 0) {
            Die("Failed to bind server socket");
          }
 
 /* Run until cancelled */
            while (1) {
              /* Receive a message from the client */
              clientlen = sizeof(echoclient);
              if ((received = recvfrom(sock, buffer, BUFFSIZE, 0,
                                       (struct sockaddr *) &echoclient,
                                       &clientlen)) < 0) {
                Die("Failed to receive message");
              }
              fprintf(stderr,
                      "Client connected: %s\n", inet_ntoa(echoclient.sin_addr));
 
            }
          }
 

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> >>>>>>

Please check my mistake, thanks again for incoming helps,

[rezamirani]

I sniffed packets in other machines that connected to the network, packet received but my receive program work bad and can't receive the packets.
Please checking my receive program "in other side program".

Best Kings.

[sicarie]

I sniffed packets in other machines that connected to the network, packet received but my receive program work bad and can't receive the packets.
Please checking my receive program "in other side program".

Best Kings.

Not sure how many of the networking people here are coders, so since you know you are receiving the packet on the destination computer (but not processing it correctly) I'm going to shift this over to the C/C++ forum - hopefully get a few more ideas over there.

[rezamirani]

Thanks ,I hope receive any help about this.