io_uring_binding_error.c

#include <errno.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sys/socket.h>
#include <unistd.h>
#include <poll.h>
#include <assert.h>
#include "liburing.h"

#define BACKLOG 512

#define PORT 9700

struct io_uring ring;

int setup_io_uring() {
    int ret = io_uring_queue_init(16, &ring, 0);
    if (ret) {
        fprintf(stderr, "Unable to setup io_uring: %s\n", strerror(-ret));
        return 1;
    }
    return 0;
}

void add_poll(int fd, unsigned int poll_mask) {
    struct io_uring_sqe *sqe = io_uring_get_sqe(&ring);
    io_uring_prep_poll_add(sqe, fd, poll_mask);
}

void add_accept(int fd) {
    struct io_uring_sqe *sqe = io_uring_get_sqe(&ring);
    io_uring_prep_accept(sqe, fd, 0, 0, SOCK_NONBLOCK | SOCK_CLOEXEC);
    sqe->user_data = 2;
}

int create_server_socket(struct sockaddr_in serv_addr) {
    int sock_listen_fd = socket(AF_INET, SOCK_STREAM | SOCK_NONBLOCK, 0);
    const int val = 1;
    setsockopt(sock_listen_fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));

    if (bind(sock_listen_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
         perror("Error binding socket\n");
         exit(1);
     }
    if (listen(sock_listen_fd, BACKLOG) < 0) {
         perror("Error listening on socket\n");
         exit(1);
    }
    return sock_listen_fd;
}

int main(int argc, char *argv[]) {
    setup_io_uring();

    struct sockaddr_in serv_addr;
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(PORT);
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    
    int sock_listen_fd1 = create_server_socket(serv_addr);

    add_poll(sock_listen_fd1, POLLIN);
    assert(io_uring_submit(&ring) == 1);
    assert(close(sock_listen_fd1) == 0); 
    
    //Error binding socket
    int sock_list_fd2 = create_server_socket(serv_addr);

    io_uring_queue_exit(&ring);

    return 0;
}