linux内核调用用户空间程序

  //内核发送端----------->
 1
#include 2 #include 3 #include 4 #include 5 #include 6 #include 7 8 #include 9 #include 10 #include 11 12 #define NETLINK_TEST 17 13 #define MAX_MSGSIZE 1024 14 struct sock *nl_sk = NULL; 15 16 static int ForkBroadprocess(void); 17 static int netlink_init(void); 18 // Send message by netlink 19 static void sendnlmsg(char *message); 20 static void netlink_exit(void); 21 static int stringlength(char *s); 22 23 24 /* 25 * 开启发送二层广播进程 26 */ 27 static int ForkBroadprocess(void) 28 { 29 netlink_init(); 30 //netlink_exit(); 31 /* 32 static char * argv_init[] = { "/usr/sbin/sendBroadcast", NULL}; 33 char * envp_init[] = {"HOME=/", "TERM=linux", "PATH=/sbin:/bin:/usr/sbin:/usr/bin", NULL}; 34 kernel_execve(argv_init[0], argv_init, envp_init); 35 printk("===============kernel_execve=================\n"); 36 */ 37 return 0; 38 } 39 40 static int netlink_init(void) 41 { 42 if(nl_sk == NULL) 43 { 44 nl_sk = netlink_kernel_create(&init_net, NETLINK_TEST, 1,NULL, NULL, THIS_MODULE); 45 } 46 if(!nl_sk){ 47 printk(KERN_ERR "my_net_link: create netlink socket error.\n"); 48 return 1; 49 } 50 51 printk("my_net_link: create netlink socket ok.\n"); 52 sendnlmsg("sendBroadcast"); 53 54 return 0; 55 } 56 57 static int stringlength(char *s) 58 { 59 int slen = 0; 60 61 for(; *s; s++){ 62 slen++; 63 } 64 65 return slen; 66 } 67 68 // Send message by netlink 69 static void sendnlmsg(char *message) 70 { 71 struct sk_buff *skb = NULL; 72 struct nlmsghdr *nlh = NULL; 73 char szMessage[32] = {0}; 74 int len = NLMSG_SPACE(MAX_MSGSIZE); 75 int slen = 0; 76 77 if(!message || !nl_sk){ 78 return; 79 } 80 81 // Allocate a new sk_buffer 82 skb = alloc_skb(len, GFP_KERNEL); 83 if(!skb){ 84 printk(KERN_ERR "my_net_link: alloc_skb Error.\n"); 85 return; 86 } 87 88 slen = stringlength(message); 89 printk("my_net_link: send message slen '%d'.\n", slen); 90 //Initialize the header of netlink message 91 nlh = nlmsg_put(skb, 0, 0, 0, MAX_MSGSIZE, 0); 92 NETLINK_CB(skb).pid = 0; // from kernel 93 NETLINK_CB(skb).dst_group = 1; // multi cast 94 //message[slen] = '/0'; 95 96 memset(szMessage, 0x0, 32); 97 memcpy(szMessage, message, slen); 98 memcpy(NLMSG_DATA(nlh), szMessage, slen + 1); 99 printk("my_net_link: send message '%s'.\n", (char *)NLMSG_DATA(nlh)); 100 101 //send message by multi cast 102 netlink_broadcast(nl_sk, skb, 0, 1, GFP_KERNEL); 103 return; 104 } 105 106 static void netlink_exit(void) 107 { 108 if(nl_sk != NULL){ 109 sock_release(nl_sk->sk_socket); 110 } 111 112 printk("my_net_link: self module exited/n"); 113 }

 //用户空间接收端

  1 #include   
  2 #include   
  3 #include   
  4 #include   
  5 #include   
  6 #include   
  7 #include <string.h>  
  8 #include   
  9 #include   
 10 #include   
 11 #include   
 12 #include 
 13 
 14 #define NETLINK_TEST 17  
 15 #define MAX_PAYLOAD 1024  // maximum payload size  
 16   
 17 static int OperateFun();
 18 
 19 int main(int argc, char* argv[])  
 20 {  
 21     struct sockaddr_nl src_addr, dest_addr;  
 22     struct nlmsghdr *nlh = NULL;  
 23     struct iovec iov;  
 24     struct msghdr msg;  
 25     int sock_fd, retval;  
 26       
 27     // Create a socket  
 28     sock_fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_TEST);  
 29     if(sock_fd == -1){  
 30         printf("error getting socket: %s", strerror(errno));  
 31         return -1;  
 32     }  
 33     printf(" getting socket: %d\n", sock_fd);    
 34     // To prepare binding  
 35     memset(&src_addr, 0, sizeof(src_addr));  
 36     src_addr.nl_family = AF_NETLINK;   
 37     src_addr.nl_pid = getpid();  // self pid   
 38     src_addr.nl_groups = 1; // multi cast  
 39     printf(" src_addr.nl_pid: %d\n", src_addr.nl_pid);    
 40     retval = bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr));  
 41     if(retval < 0){  
 42         printf("bind failed: %s", strerror(errno));  
 43         close(sock_fd);  
 44         return -1;  
 45     }  
 46      //printf(" ====================0000\n");     
 47     // To prepare recvmsg  
 48     nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(MAX_PAYLOAD));  
 49     if(!nlh){  
 50         printf("malloc nlmsghdr error!/n");  
 51         close(sock_fd);  
 52         return -1;  
 53     }  
 54   //printf(" ====================11111\n");   
 55     memset(nlh, 0, NLMSG_SPACE(MAX_PAYLOAD));  
 56     iov.iov_base = (void *)nlh;  
 57     iov.iov_len = NLMSG_SPACE(MAX_PAYLOAD);  
 58   //printf(" ====================22222\n");   
 59     memset(&msg, 0, sizeof(msg));  
 60     memset(&dest_addr, 0, sizeof(dest_addr));  
 61     msg.msg_name = (void *)&dest_addr;  
 62     msg.msg_namelen = sizeof(dest_addr);  
 63     msg.msg_iov = &iov;  
 64     msg.msg_iovlen = 1;  
 65   //printf(" ====================33333\n");   
 66     // Read message from kernel  
 67 
 68     int nSelectRet = 0;
 69     fd_set fdReadSet;
 70     struct timeval stTimeOut = {0};
 71 
 72     for(;;)
 73     {
 74         //wait for a message
 75         //printf(" ====================4444444\n");   
 76         FD_ZERO(&fdReadSet);
 77         FD_SET(sock_fd, &fdReadSet);
 78         //printf(" ====================55555555\n");  
 79         stTimeOut.tv_sec = 2;
 80         stTimeOut.tv_usec = 0;
 81         nSelectRet = select(sock_fd + 1, &fdReadSet, NULL, NULL, &stTimeOut);
 82     
 83 
 84         if(0 > nSelectRet)
 85         {
 86             printf( "select error !");
 87         }
 88         else if(0 == nSelectRet)
 89         {
 90             printf( "select time out !\n");
 91 
 92         }
 93         else
 94         {
 95             if(FD_ISSET(sock_fd, &fdReadSet))
 96             {
 97                 recvmsg(sock_fd, &msg, 0);  
 98                 printf("Received message: %s\n", NLMSG_DATA(nlh));  
 99                 OperateFun();
100             }
101         }
102     }
103     close(sock_fd);  
104   
105     return 0;  
106 }

 

转载于:https://www.cnblogs.com/liwentao1091/p/4535881.html

你可能感兴趣的:(linux内核调用用户空间程序)