Function sys_accept

components/lwp/lwp_syscall.c:5092–5134

* @brief Accepts a connection on a socket. * * This system call is used to accept a pending connection request on a socket. It extracts the * first connection request from the incoming queue, creates a new socket for the connection, * and stores the address information of the remote peer in the provided address structure. * The original socket must be a listening socket that has been previous

 *          to buffer overflows or undefined behavior.
 */
sysret_t sys_accept(int socket, struct musl_sockaddr *addr, socklen_t *addrlen)
{
    int ret = -1;
    struct sockaddr ksa;
    struct musl_sockaddr kmusladdr;
    socklen_t uaddrlen;
    socklen_t kaddrlen;

    if (addr)
    {
        if (!lwp_user_accessable(addrlen, sizeof(socklen_t)))
        {
            return -EFAULT;
        }
        lwp_get_from_user(&uaddrlen, addrlen, sizeof(socklen_t));
        if (!uaddrlen)
        {
            return -EINVAL;
        }

        if (!lwp_user_accessable(addr, uaddrlen))
        {
            return -EFAULT;
        }
    }

    kaddrlen = sizeof(struct sockaddr);
    ret = accept(socket, &ksa, &kaddrlen);
    if (ret >= 0)
    {
        if (addr)
        {
            sockaddr_tomusl(&ksa, &kmusladdr);
            if (uaddrlen > sizeof(struct musl_sockaddr))
            {
                uaddrlen = sizeof(struct musl_sockaddr);
            }
            lwp_put_to_user(addr, &kmusladdr, uaddrlen);
            lwp_put_to_user(addrlen, &uaddrlen, sizeof(socklen_t));
        }
    }
    return ret;
}

/**
 * @brief Binds a socket to a local address.