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how to bind a UDP socket to a range of port

I want to write a kernel thread for an application that will read all UDP packets. I am facing problem in bindin开发者_运维问答g as these packet can arrive in range of ports (say 5001 to 5005).

How to do this. Any pointer/link will be helpful.


You can't bind a socket to more than one port, do as 0verbose suggested in a comment and use one socket per port


Besides opening multiple sockets, you need to use select()/poll() to listen to all sockets at once. If you are programming in C/C++ under Linux, here is a pseudo-code in C:

#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

...

int main()
{
    fd_set afds;
    fd_set rfds;
    int maxfd = -1;
    int fd, ret;

    /* initialize fdsets */
    FD_ZERO(&afds);

    /* create a socket per port */
    foreach (port p) {
        fd = create_udp_socket(p);  /* also bind to port p */
        if (fd < 0) error_exit("error: socket()\n");
        FD_SET(fd, &afds);
        if (fd > maxfd) maxfd = fd;
    }

    while (1) {
        memcpy(&rfds, &afds, sizeof(rfds));

        /* wait for a packet from any port */
        ret = select(maxfd + 1, &rfds, NULL, NULL, NULL);
        if (ret < 0) error_exit("error: select()\n");

        /* which socket that i received the packet */
        for (fd=0; fd<=maxfd; ++fd) 
            if (FD_ISSET(fd, &rfds)) 
                process_packet(fd); /* read the packet from socket fd */ 

    }

}

Hope this code will help you

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