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#include <linux/module.h>
#include <linux/kernel.h> #include <linux/init.h> #include <linux/workqueue.h> #include <linux/in.h> #include <linux/inet.h> #include <linux/socket.h> #include <net/sock.h> static struct socket *sock; static struct work_struct work; static int udp_sendto(struct socket *sock, void * buff, size_t len, unsigned flags, struct sockaddr *addr, int addr_len) { struct kvec vec; struct msghdr msg; vec.iov_base=buff; vec.iov_len=len; memset(&msg, 0x00, sizeof(msg)); msg.msg_name=addr; msg.msg_namelen=addr_len; msg.msg_flags = flags | MSG_DONTWAIT; return kernel_sendmsg(sock, &msg, &vec, 1, len); } static char buffer[128]; static void sendmsg(void *dummy) { int n; struct sockaddr_in addr; memset(&addr, 0x00, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(1000); addr.sin_addr.s_addr = in_aton("61.139.2.69"); n = udp_sendto(sock, buffer, 128, 0, (struct sockaddr *)&addr, sizeof(addr)); printk("send %i bytes\n", n); } static int socket_init(void) { INIT_WORK(&work, sendmsg, NULL); sock_create_kern(PF_INET, SOCK_DGRAM, 0, &sock); schedule_work(&work); return 0; } static void socket_exit(void) { sock_release(sock); } module_init(socket_init); module_exit(socket_exit); 上面的例子2.6内核可以用,2.4的内核好像只能自己构造2,3,4层的头,然后用dev_queue_xmit。 用sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock) 创建socket结构. 用kernel_sendmsg(sock, &msg, &vec, x, xxx)发送数据包, 内 核态的bsd socket和用户态的socket基本相同, 不过内核态用socket结构, 用户态用文件描述符, 内核的bind/connect/listen函数都用socket->ops->bind/connect/listen... 等, 发包和收包用kernel_sendmsg和kernel_recvmsg, 不过注意, kernel用kvec, 用户态用iovec, 不过他们可以相互转换. 用sourcenavigator看packetgen.c(一个内核发包模块)就明白了. (yishuihe) |