Chinaunix

标题: FREEBSD6.0下添加路由的问题 [打印本页]

作者: IORIyagami20 时间: 2009-05-04 17:16
标题: FREEBSD6.0下添加路由的问题
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);
}

作者: IORIyagami20 时间: 2009-05-04 20:15
忘记讲了
如果是单个IP，那么就会显示网关，但标记还是不正确
# ./addrt 192.168.4.10 192.168.0.8 255.255.255.255
# netstat -rn
192.168.4.10/32 192.168.0.8 U 0 0 lnc0

作者: IORIyagami20 时间: 2009-05-05 10:45
基本上把问题定在netmask写入方面，掩码不是用sockaddr_in来写的，但我还不知道用什么来写用sockaddr?
希望大家给我个提示

作者: IORIyagami20 时间: 2009-05-06 10:48
问题已经解决了
主要有2个问题，一个是掩码写入问题，一个是忘记写flags了，哈哈
下面贴下代码
#include       "unproute.h"

#define BUFLEN  (sizeof(struct rt_msghdr) + 512)

#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;
      struct sockaddr       sin3;
      if (argc != 4)
            err_quit("usage: addrrt <IPaddress> <gw> <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) + 2*sizeof(struct sockaddr_in)+sizeof(struct sockaddr);
      rtm->rtm_version = RTM_VERSION;
      rtm->rtm_type = RTM_ADD;
      rtm->rtm_flags=RTF_UP | RTF_GATEWAY |RTF_STATIC;
      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 *) (sin2+1);
      sin3->sa_len=8;
      Inet_pton(AF_INET,argv[3],&sin3->sa_data[2]);
      Write(sockfd, rtm, rtm->rtm_msglen);

      exit(0);
}

欢迎光临 Chinaunix (http://bbs.chinaunix.net/)