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写了个程序,但发现有问题,但不知道问题在那里,请各位大侠指教,谢谢
说下情况:编译成功,可以添加但和route add添加出来有不同
如:# route add 192.168.1.0 192.168.0.8 255.255.255.0
# netstat -rn
192.168.1 192.168.0.8 UGS 0 0 lnc0
但如果用我自己写的程序会发生下面的情况
# ./addrt 192.168.4.0 192.168.0.8 255.255.255.0
# netstat -rn
192.168.4 link#1 UC 0 0 lnc0
与route相比添加后算直连的,没有GS标记,替代的是克隆掩码
代码如下:
#include "unproute.h"
#define BUFLEN (sizeof(struct rt_msghdr) + 3*sizeof(struct sockaddr_in))
/* sizeof(struct sockaddr_in6) * 8 = 192 */
#define SEQ 9999
int
main(int argc, char **argv)
{
int sockfd;
char *buf;
pid_t pid;
struct rt_msghdr *rtm;
struct sockaddr_in *sin,*sin2,*sin3;
if (argc != 4)
err_quit("usage: addrrt <IPaddress> <IPaddress> <netmask>");
sockfd = Socket(AF_ROUTE, SOCK_RAW, 0); /* need superuser privileges */
buf = Calloc(1, BUFLEN); /* and initialized to 0 */
rtm = (struct rt_msghdr *) buf;
rtm->rtm_msglen = sizeof(struct rt_msghdr) + 3*sizeof(struct sockaddr_in);
rtm->rtm_version = RTM_VERSION;
rtm->rtm_type = RTM_ADD;
rtm->rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
rtm->rtm_pid = pid = getpid();
rtm->rtm_seq = SEQ;
sin = (struct sockaddr_in *) (rtm + 1);
sin->sin_len = sizeof(struct sockaddr_in);
sin->sin_family = AF_INET;
Inet_pton(AF_INET, argv[1], &sin->sin_addr);
sin2 = (struct sockaddr_in *) (sin+1);
sin2->sin_len = sizeof(struct sockaddr_in);
sin2->sin_family = AF_INET;
Inet_pton(AF_INET, argv[2], &sin2->sin_addr);
sin3 = (struct sockaddr_in *) (sin2+1);
sin3->sin_len = sizeof(struct sockaddr_in);
sin3->sin_family = AF_INET;
Inet_pton(AF_INET, argv[3], &sin3->sin_addr);
Write(sockfd, rtm, rtm->rtm_msglen);
} |
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