netlink

问题 The task I am trying to achieve is actually quite simple (multicast the string "TEST" to a userland daemon), but the kernel module doesn't compile. It stops with the error: passing argument 4 of ‘genlmsg_multicast_allns’ makes integer from pointer without a cast [enabled by default] But shouldn't it just be the multicast group I defined? Here is the code for "clarification": #include <linux/module.h> #include <net/sock.h> #include <linux/netlink.h> #include <linux/skbuff.h> #include <linux

问题 i was going through ioctl sample programs to check how it communicates with kernel space. in program WRITE_IOCTL is used as command #define WRITE_IOCTL _IOW(MY_MACIG, 1, int) ioctl(fd, WRITE_IOCTL, "hello world") I am not able to understand what is _IOW(MY_MACIG, 1, int) . here is the link from where i downloaded the program. please help me. http://people.ee.ethz.ch/~arkeller/linux/multi/kernel_user_space_howto-4.html 回答1: As you may know, an ioctl should be unique, as explained in the Linux

问题 I tried this program. This program send "hello" to kernel and kernel replies "hello" to user space again for one time. My requirement: user has to send "hello" and have to receive message for every 2 seconds. What I have tried. User app : added loopfor sending and receiving #define NETLINK_USER 31 #define MAX_PAYLOAD 1024 /* maximum payload size*/ struct sockaddr_nl src_addr, dest_addr; struct nlmsghdr *nlh = NULL; struct iovec iov; int sock_fd; struct msghdr msg; int main() { sock_fd=socket

问题 I'm writing multicast client/server application based on this and this; which work great. However, I would also need to do something when the number of active network interfaces in the computer changes, something like what the program in the example section of this page does. I guess I should use the tools in boost::asio::local, but I am unsure whether I should use boost::asio::local::datagram_protocol or boost::asio::local::stream_protocol or... An example of how to do something as similar

问题 Hi, I've been working on trying to get Netlink sockets to work for the 3.2 linux kernel , but I cannot seem to figure out how to do it. I have looked around for examples of the basics of Netlink sockets, but it seems all of the examples I find are for the 2.6 kernel. What I'm trying to find is how to send information from a kernel module to user mode application and vice-versa using Netlink sockets? Any help would be greatly appreciated. Thanks! 回答1: I've been working on using Netlink sockets

问题 I am trying to make Kernel (Android, kernel 4.9.59) communicate with userspace applications. I found a solution using Netlink sockets: https://stackoverflow.com/a/25071310/4190159 The first issue with the solution is that struct netlink_skb_parms used in the solution does not have a member named 'pid', instead has a member named 'portid', which I believe is not the same as pid. Anyway, to compile my kernel side code/solution I used 'portid' member of struct netlink_skb_parms instead for

问题 I am trying to develop a function which would enable the Kernel (Android kernel: 4.9.59) to send a message to an/many userspace application and I have followed this example: Kernel to userspace application communication However, when I am trying to call the message conveying function from the scheduler I am receiving the following error: Fatal exception PC is at netlink_broadcast_filtered+0x24/0x3d4 LR is at netlink_broadcast+0x14/0x20 Inside the kernel scheduler (kernel/sched) I have created

问题 I'm creating a C library that manages a lot of peripherical of my embedded device. The S.O. used, is a Linux distro compiled with yocto. I'm trying to make some functions to connect my device to wifi (well-know) router, with netlink (using the libnl commands). With the help of this community, I've developed a function able to scan the routers in the area. Some of you know how to use the libnl command to connecting my device to router wifi? I've developed the following code, that tries to

问题 (Linux 4.4) I am trying to get a kernel module to send information to a user process over a Generic Netlink. It seems that the message is not successfully received by the user process - the nlmsg_unicast function returns with -111. Here is what I know: The kernel module successfully registers a Generic Netlink family - it prints a message in the syslog indicating the (autogenerated) family ID (which is always 26). The user process successfully discovers the family ID (26). The user process

问题 As all know, netlink it's user/kernel space communication mechanism. I want to communicate from my kernel module to an another. Another kernel module already has the netlink interface. Is it possible to make connection from kernel module to netlink, as we do it in user space? 回答1: Short answer: No. If you want to communicate between two kernel modules you should use symbols (global variables or functions) which are exported by the other kernel module. netlink Sockets are used to communicate