62 lines
1.4 KiB
C
62 lines
1.4 KiB
C
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#include <sys/socket.h>
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#include <linux/netlink.h>
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#include <stdlib.h>
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#include <string.h>
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#include <stdio.h>
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#define NETLINK_USER 30
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#define MAX_PAYLOAD 1024 /* maximum payload size*/
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int main()
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{
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struct sockaddr_nl src_addr, dest_addr;
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struct nlmsghdr *nlh = NULL;
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struct iovec iov;
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int sock_fd;
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struct msghdr msg;
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sock_fd=socket(PF_NETLINK, SOCK_RAW, NETLINK_USER);
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if(sock_fd<0)
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return -1;
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memset(&src_addr, 0, sizeof(src_addr));
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src_addr.nl_family = AF_NETLINK;
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src_addr.nl_pid = getpid(); /* self pid */
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bind(sock_fd, (struct sockaddr*)&src_addr, sizeof(src_addr));
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memset(&dest_addr, 0, sizeof(dest_addr));
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memset(&msg, 0, sizeof(msg));
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dest_addr.nl_family = AF_NETLINK;
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dest_addr.nl_pid = 0; /* For Linux Kernel */
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dest_addr.nl_groups = 0; /* unicast */
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nlh = (struct nlmsghdr *)malloc(NLMSG_SPACE(MAX_PAYLOAD));
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memset(nlh, 0, NLMSG_SPACE(MAX_PAYLOAD));
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nlh->nlmsg_len = NLMSG_SPACE(MAX_PAYLOAD);
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nlh->nlmsg_pid = getpid();
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nlh->nlmsg_flags = 0;
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strcpy(NLMSG_DATA(nlh), "Hello");
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iov.iov_base = (void *)nlh;
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iov.iov_len = nlh->nlmsg_len;
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msg.msg_name = (void *)&dest_addr;
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msg.msg_namelen = sizeof(dest_addr);
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msg.msg_iov = &iov;
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msg.msg_iovlen = 1;
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printf("Sending message to kernel\n");
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sendmsg(sock_fd,&msg,0);
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printf("Waiting for message from kernel\n");
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/* Read message from kernel */
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recvmsg(sock_fd, &msg, 0);
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printf("Received message payload: %s\n", (char *)NLMSG_DATA(nlh));
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close(sock_fd);
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}
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