netlink例子(2)

最新推荐文章于 2024-04-27 21:20:02 发布

wxm_linux

最新推荐文章于 2024-04-27 21:20:02 发布

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分类专栏： linux_driver 文章标签： struct user module socket 2010 null

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一个网友写的,不知道网址了...

注意这里的代码在不同的内核中是不一样的,好像我就是改了一些...

比如:netlink_kernel_create这个函数在不同版本的内核里参数个数也不一样.

我用的内核是:linux-2.6.32

nl.h

#ifndef __nl_h__ #define __nl_h__ #define My_netlink 26 #define U_PID 1 #define K_MSG 2 #endif struct { __u32 pid; }user_proc;

kernel_src.c

/* * Copyright (c) 2010-~ zhouyongfei * * The source code is released for free distribution under the terms of the GNU General Public License * * * Author: alen Chou<zhouyongfei1988@gmail.com> * Created Time: 2010年11月15日星期一 09时24分35秒 * Description: * */ #include <linux/module.h> #include <linux/init.h> #include <linux/netlink.h> #include <net/sock.h> #include "nl.h" static struct sock *nlfd; int send_to_user(char *info) //发送到用户态 { int size; struct sk_buff *skb; unsigned char *old_tail; struct nlmsghdr *nlh; int retval; size = NLMSG_SPACE(strlen(info)); skb = alloc_skb(size, GFP_ATOMIC); nlh = nlmsg_put(skb,0,0,0,NLMSG_SPACE(strlen(info))-sizeof(struct nlmsghdr),0); old_tail = skb->tail; memcpy(NLMSG_DATA(nlh),info,strlen(info)); nlh->nlmsg_len = skb->tail - old_tail; NETLINK_CB(skb).pid = 0; //NETLINK_CB(skb).dst_pid = user_proc.pid; NETLINK_CB(skb).dst_group = 0; printk("in kernel,skb->data:%s/n",(char *)NLMSG_DATA((struct nlmsghdr *)skb->data)); retval = netlink_unicast(nlfd, skb, user_proc.pid, MSG_DONTWAIT); printk("netlink_unicast retuen: %d/n",retval); return 0; } void kernel_receive(struct sk_buff* __skb) //内核接受函数 { struct sk_buff *skb; struct nlmsghdr *nlh = NULL; char *data = "hello,this is alenchou's message from kernel/n"; printk("begin kernel_receive/n"); skb = skb_get(__skb); if(skb->len >= sizeof(struct nlmsghdr)) { printk("kernel coming here in if/n"); nlh = (struct nlmsghdr *)skb->data; if((nlh->nlmsg_len >= sizeof(struct nlmsghdr)) && (__skb->len >= nlh->nlmsg_len)) { user_proc.pid = nlh->nlmsg_pid; printk("data receive from user are:%s/n",(char *)NLMSG_DATA(nlh)); printk("user_pid:%d/n",user_proc.pid); send_to_user(data); } }else { printk("kernle coming here in else!!/n"); printk("user data:%s/n",(char *)NLMSG_DATA(nlmsg_hdr(__skb))); send_to_user(data); } kfree_skb(skb); } int __init nl_init(void) { printk("nl start!!/n"); nlfd = netlink_kernel_create(&init_net, My_netlink, 0, kernel_receive, NULL, THIS_MODULE); if(!nlfd){ printk("can not create a netlink socket/n"); return -1; } return 0; } void __exit nl_exit(void) { sock_release(nlfd->sk_socket); printk("nl exit!!/n"); } MODULE_LICENSE("GPL"); module_init(nl_init); module_exit(nl_exit);

user_src.c

/* * Copyright (c) 2010-~ zhouyongfei * * The source code is released for free distribution under the terms of the GNU General Public License * * * Author: alen Chou<zhouyongfei1988@gmail.com> * Created Time: 2010年11月15日星期一 09时24分35秒 * Description: * */ #include <stdio.h> #include <sys/socket.h> #include <stdlib.h> #include <string.h> #include <linux/netlink.h> #include "nl.h" struct msg_to_kernel { struct nlmsghdr hdr; char data[100]; }; struct u_packet_info { struct nlmsghdr hdr; char msg[100]; }; int main(void) { char *data = "hello,this is from alen's space/0"; //初始化 struct sockaddr_nl local; struct sockaddr_nl kpeer; int skfd,ret,kpeerlen = sizeof(struct sockaddr_nl);; //struct msg_to_kernel message; struct nlmsghdr *message; struct u_packet_info info; char *retval; message = (struct nlmsghdr *)malloc(1); skfd = socket(PF_NETLINK, SOCK_RAW, My_netlink); if(skfd < 0){ printf("can not create a netlink socket/n"); return -1; } memset(&local, 0, sizeof(local)); local.nl_family = AF_NETLINK; local.nl_pid = getpid(); local.nl_groups = 0; if(bind(skfd, (struct sockaddr*)&local, sizeof(local)) != 0){ printf("bind() error/n"); return -1; } memset(&kpeer, 0, sizeof(kpeer)); kpeer.nl_family = AF_NETLINK; kpeer.nl_pid = 0; kpeer.nl_groups = 0; memset(message,'/0', sizeof(struct nlmsghdr)); message->nlmsg_len = NLMSG_SPACE(strlen(data)); message->nlmsg_flags = 0; message->nlmsg_type = 0;//U_PID; message->nlmsg_seq = 0; message->nlmsg_pid = local.nl_pid; retval = memcpy(NLMSG_DATA(message),data,strlen(data)); //初始化结束 //发送进程PID printf("message sendto kernel are:%s,len:%d/n",(char *)NLMSG_DATA(message),message->nlmsg_len); ret = sendto(skfd, message, message->nlmsg_len, 0,(struct sockaddr *)&kpeer, sizeof(kpeer)); if(!ret){ perror("send pid:"); exit(-1); } //接受内核态确认信息 ret = recvfrom(skfd, &info, sizeof(struct u_packet_info),0, (struct sockaddr*)&kpeer, &kpeerlen); if(!ret){ perror("recv form kerner:"); exit(-1); } printf("message from kernel:%s/n",(char *)info.msg); //内核和用户进行通信 close(skfd); return 0; }

Makefile

obj-m:=kernel_src.o KDIR=/lib/modules/$(shell uname -r)/build all: make -C $(KDIR) M=$(PWD) modules clean: make -C $(KDIR) M=$(PWD) clean