Add netlink socket

2 files changed, 36 insertions, 26 deletions

diff --git a/md/notes/kernel/netlink_socket.md b/md/notes/kernel/netlink_socket.md
index 01e9043..e022e52 100644
--- a/md/notes/kernel/netlink_socket.md
+++ b/md/notes/kernel/netlink_socket.md
@@ -3,11 +3,11 @@ keywords: kernel,linux,netlink,socket
 
 # Kernel compile "Hello world"
 
-Compile minimal linux kernel module. 
+As base start from minimal kernel module
 
 ## Files
 
-You need to create to files __Makefile__ and __hello_world.c__.
+You need to create to files __Makefile__ and __netlink_socket.c__.
 
 __Makefile__
 ```Makefile
@@ -206,51 +206,51 @@ create utility that connects and interacts with netlink socket.
 
 int main(int argc, char **argv) {
 
-    struct sockaddr_nl src_addr;
-    struct sockaddr_nl dest_addr;
-    struct nlmsghdr *nlh;
-    struct msghdr msg;
-    struct iovec iov;
-    int sock_fd;
-    int ret;
+	struct sockaddr_nl src_addr;
+	struct sockaddr_nl dest_addr;
+	struct nlmsghdr *nlh;
+	struct msghdr msg;
+	struct iovec iov;
+	int sock_fd;
+	int ret;
 
 
-    sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_PROTO);
+	sock_fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_PROTO);
 	if (sock_fd < 0)
 	{
 		printf("socket creation for NETLINK failed...\n");
 		return -1;
 	}
 
-    memset(&src_addr, 0, sizeof(src_addr));
+	memset(&src_addr, 0, sizeof(src_addr));
 	src_addr.nl_family = AF_NETLINK;
 	src_addr.nl_pid = getpid();
 	bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr));
 
-    nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(PAYLOAD_SIZE));
+	nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(PAYLOAD_SIZE));
 	memset(nlh, 0, NLMSG_SPACE(PAYLOAD_SIZE));
 	nlh->nlmsg_len = NLMSG_SPACE(PAYLOAD_SIZE);
 	nlh->nlmsg_pid = getpid();
 	nlh->nlmsg_flags = 0;
 
-    strcpy(NLMSG_DATA(nlh), "Test test Test!");
+	strcpy(NLMSG_DATA(nlh), "Test test Test!");
 
-    memset(&dest_addr, 0, sizeof(dest_addr));
+	memset(&dest_addr, 0, sizeof(dest_addr));
 	dest_addr.nl_family = AF_NETLINK;
 	dest_addr.nl_pid = 0;		// Linux Kernel PID
 	dest_addr.nl_groups = 0;
 
-    memset(&iov, 0, sizeof(iov));
-    iov.iov_base = (void *)nlh;
-    iov.iov_len = nlh->nlmsg_len;
+	memset(&iov, 0, sizeof(iov));
+	iov.iov_base = (void *)nlh;
+	iov.iov_len = nlh->nlmsg_len;
 
-    memset(&msg, 0, sizeof(msg));
-    msg.msg_name = (void *)&dest_addr;
-    msg.msg_namelen = sizeof(dest_addr);
-    msg.msg_iov = &iov;
-    msg.msg_iovlen = 1;
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_name = (void *)&dest_addr;
+	msg.msg_namelen = sizeof(dest_addr);
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
 
-    ret = sendmsg(sock_fd, &msg, 0);
+	ret = sendmsg(sock_fd, &msg, 0);
 	printf("Message sent, payload: %s\n", (char *)NLMSG_DATA(nlh));
 
 	// Clear netlink packet payload:
@@ -260,9 +260,9 @@ int main(int argc, char **argv) {
 	ret = recvmsg(sock_fd, &msg, 0);
 	printf("Message received, payload: %s\n", (char *)NLMSG_DATA(nlh));
 
-    close(sock_fd);
+	close(sock_fd);
 
-    return 0;
+	return 0;
 }
 ```
 
diff --git a/md/notes/kernel/topics.md b/md/notes/kernel/topics.md
index d955193..8682aeb 100644
--- a/md/notes/kernel/topics.md
+++ b/md/notes/kernel/topics.md
@@ -5,7 +5,10 @@ keywords:blog,projects
 
 Linux kernel programming topics, mostly for those who have some programming
 experience and linux command line expertise. Making notes on all fundamental 
-kernel API's. 
+kernel API's and gathering all examples from all over the internet, all is
+compiled and test on Raspberry Pi 4 kernel 6.6.20. No other versions of kernel
+is checked. With move one to new SoC or new kernel all examples will also update
+accordingly. 
 
 ## Topic
 
@@ -47,7 +50,14 @@ kernel API's.
 <!-- Virtual Pinctrl driver -->
 <!-- Create key logger  -->  
 <!-- Create device tree entry  -->  
+<!-- Netfilter ICMP filter -->
+<!-- Bpf filter -->
+
 
 ### Kernel userspace
 
+[Netlink show ip](/notes/kernel/netlink_show_ip.md)   
+<!-- Netfilter set ip -->
+<!-- khttpd -->
+