For better understanding about my doubt, here is the full code. It is based at http://www.linuxjournal.com/article/7356. I have applied some changes because the available version is based on older kernel. #include <linux/socket.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/netlink.h> #include <net/sock.h> #define NETLINK_TEST 17 MODULE_LICENSE("GPL"); MODULE_AUTHOR("Test"); MODULE_DESCRIPTION("Testing Kernel/User socket"); static int debug = 0; module_param(debug, int, 0); MODULE_PARM_DESC(debug, "Debug information (default 0)"); static struct sock *nl_sk = NULL; static void nl_data_ready (struct sock *sk, int len) { wake_up_interruptible(sk->sk_sleep); } static void netlink_test(void) { struct sk_buff *skb = NULL; struct nlmsghdr *nlh = NULL; int err; u32 pid; nl_sk = netlink_kernel_create(NETLINK_TEST, 0, nl_data_ready, THIS_MODULE); if (!nl_sk) { printk(KERN_ERR "netlink_test: unable to create netlink socket!\n"); return; } skb = skb_recv_datagram(nl_sk, 0, 0, &err); if (!skb) { printk(KERN_ERR "netlink_test: skb_recv_datagram!\n"); return; } nlh = (struct nlmsghdr *)skb->data; printk(KERN_INFO "%s: received netlink message payload: %s\n", __FUNCTION__, (char *)NLMSG_DATA(nlh)); pid = nlh->nlmsg_pid; NETLINK_CB(skb).pid = 0; NETLINK_CB(skb).dst_pid = pid; NETLINK_CB(skb).dst_group = 0; netlink_unicast(nl_sk, skb, pid, MSG_DONTWAIT); sock_release(nl_sk->sk_socket); } static int __init my_module_init(void) { printk(KERN_INFO "Initializing Netlink Socket\n"); netlink_test(); return 0; } static void __exit my_module_exit(void) { printk(KERN_INFO "Goodbye\n"); } module_init(my_module_init); module_exit(my_module_exit); --- Mauricio Lin <mauriciolin2000@xxxxxxxxxxxx> escreveu: > Hi all, > > I am using a module that employs netlink functions and data. > > After compiling it, I insert the module as: > > # insmod test.ko > > but the terminal (prompt) gets locked. After debugging the module, I > noticed that skb_recv_datagram() is responsible for that. > > Take a look the snippet of the code: > > skb = skb_recv_datagram(nl_sk, 0, 0, &err); > if (!skb) { > printk(KERN_ERR > "netlink_test: skb_recv_datagram!\n"); > return; > } > > When I interrupt the prompt (as it was locked by inserting the > module) > typing <Control>+C, the message "netlink_test: skb_recv_datagram!" is > printed, so I wonder why this is happening. > > Is it normal skb_recv_datagram() blocks the terminal? How can I solve > it? > > BR, > > Mauricio Lin. > > > > _______________________________________________________ > Novidade no Yahoo! Mail: receba alertas de novas mensagens no seu > celular. Registre seu aparelho agora! > http://br.mobile.yahoo.com/mailalertas/ > > > > -- > Kernelnewbies: Help each other learn about the Linux kernel. > Archive: http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > > _______________________________________________________ Yahoo! Acesso Grátis - Internet rápida e grátis. Instale o discador agora! http://br.acesso.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
