使用netlink的ipv6本地地址

我使用netlink編寫C代碼來獲取有關ip route table的信息並檢測gived接口的新ip地址。使用IPv4，我可以使用'IFA_LOCAL'過濾本地地址。但使用IPv6，我無法獲得本地地址。即使是本地地址，rta_type也不會等於'IFA_LOCAL'。使用netlink的ipv6本地地址

所使用的代碼如下：

int main(void) 
{ 
    struct { 
     struct nlmsghdr hdr; 
     struct ifaddrmsg msg; 
    } req; 
    struct sockaddr_nl addr; 
    int sock[2]; 

    memset(&addr, 0, sizeof(addr)); 
    memset(&req, 0, sizeof(req)); 

    if ((sock[0] = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) == -1) { 
     CWMP_LOG(ERROR,"couldn't open NETLINK_ROUTE socket"); 
     return -1; 
    } 

    addr.nl_family = AF_NETLINK; 
    addr.nl_groups = RTMGRP_IPV6_IFADDR;// |RTMGRP_IPV6_IFADDR; 
    if ((bind(sock[0], (struct sockaddr_in6 *)&addr, sizeof(addr))) == -1) { 
     CWMP_LOG(ERROR,"couldn't bind netlink socket"); 
     return -1; 
    } 

    netlink_event.fd = sock[0]; 
    if ((sock[1] = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE)) == -1) { 
     CWMP_LOG(ERROR,"couldn't open NETLINK_ROUTE socket"); 
     return -1; 
    } 

    req.hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); 
    req.hdr.nlmsg_flags = NLM_F_REQUEST | NLM_F_ROOT; 
    req.hdr.nlmsg_type = RTM_GETADDR; 
    req.msg.ifa_family = AF_INET6; 

    if ((send(sock[1], &req, req.hdr.nlmsg_len, 0)) == -1) { 
     CWMP_LOG(ERROR,"couldn't send netlink socket"); 
     return -1; 
    } 

    struct nlmsghdr *nlh; 
    char buffer[BUFSIZ]; 
    int msg_size; 

    memset(&buffer, 0, sizeof(buffer)); 

    nlh = (struct nlmsghdr *)buffer; 
    if ((msg_size = recv(sock[1], nlh, BUFSIZ, 0)) == -1) { 
     CWMP_LOG(ERROR,"error receiving netlink message"); 
     return; 
    } 

    while (msg_size > sizeof(*nlh)) { 
     int len = nlh->nlmsg_len; 
     int req_len = len - sizeof(*nlh); 

     if (req_len < 0 || len > msg_size) { 
      CWMP_LOG(ERROR,"error reading netlink message"); 
      return; 
     } 

     if (!NLMSG_OK(nlh, msg_size)) { 
      CWMP_LOG(ERROR,"netlink message is not NLMSG_OK"); 
      return; 
     } 

     if (nlh->nlmsg_type == RTM_NEWADDR) { 
      printf("new addr \n"); 
      struct ifaddrmsg *ifa = (struct ifaddrmsg *) NLMSG_DATA(nlh); 
      struct rtattr *rth = IFA_RTA(ifa); 
      int rtl = IFA_PAYLOAD(nlh); 
      char if_name[IFNAMSIZ], if_addr[INET6_ADDRSTRLEN]; 
      char *c; 
      struct in6_addr *in6p; 

      memset(&if_name, 0, sizeof(if_name)); 
      memset(&if_addr, 0, sizeof(if_addr)); 

      while (rtl && RTA_OK(rth, rtl)) { 
       printf("rth->rta_type %d \n", rth->rta_type); 
       in6p = (struct in6_addr *)RTA_DATA(rth); 
       printf("addr1: " NIP6_FMT "\n",NIP6(*in6p)); 
       if (rth->rta_type != IFA_LOCAL) { 
        printf("########NOT IFA_LOCAL ############\n"); 
        rth = RTA_NEXT(rth, rtl); 
        continue; 
       } 
       printf("======IFA_LOCAL======\n"); 
       rth = RTA_NEXT(rth, rtl);     
      } 
     } 
     msg_size -= NLMSG_ALIGN(len); 
     nlh = (struct nlmsghdr*)((char*)nlh + NLMSG_ALIGN(len)); 
    } 
    return 0; 
}

和執行的軌跡以下： rth-> rta_type 6 ADDR1：0000：0e0e：0000：1c1e：0031：15c7：0031： 15c7

## NOT IFA_LOCAL

新地址 rth-> rta_type 1 ADDR1：fd59：ca3e：bd63：0000：0222：07FF：fe41：b9d6

## NOT IFA_LOCAL

rth-> rta_type 6 ADDR1：0000：068c：0000：1ba4：0030：e60b：0030：e60b

## NOT IFA_LOCAL

新地址 rth-> rta_type 1 ADDR1：2001：1338 ：000A：0000：0000：0000：0000：0196

## NOT IFA_LOCAL

rth-> rta_type 6 ADDR1：FFFF：FFFF：FFFF：FFFF：0005：A828：0005：A828

## NOT IFA_LOCAL

新地址 rth-> rta_type 1 ADDR1：FE80：0000：0000：0000：0222：07FF：fe41：b9d6

## NOT IFA_LOCAL

rth-> rta_type 6 ADDR1：FFFF：FFFF：FFFF ：FFFF：0005：A826：0005：A826

## NOT IFA_LOCAL

新地址 rth-> rta_type 1 ADDR1：FE80：0000：0000：0000：0222：07FF：fe41：b9d7

＃ #NOT IFA_LOCAL

來源

2016-09-22 imen bhiri

如果您正在尋找本地鏈路地址，只需用'/ 10掩碼地址'，然後將它與'fe80 ::/10'進行比較。如果匹配，則它是一個鏈接本地地址。 –

這不是我想要的。 –

你在找什麼？ –

試着找r「IFA_ADDRESS」。對於廣播接口，IFA_LOCAL和IFA_ADDRESS意味着相同。以下是來自內核if_addr.h的代碼段。（：inet6_fill_ifaddr（）addrconf.c）：

/* 
* Important comment: 
* IFA_ADDRESS is prefix address, rather than local interface address. 
* It makes no difference for normally configured broadcast interfaces, 
* but for point-to-point IFA_ADDRESS is DESTINATION address, 
* local address is supplied in IFA_LOCAL attribute. 
*/ 
enum { 
    IFA_UNSPEC, 
    IFA_ADDRESS, 
    IFA_LOCAL, 
    IFA_LABEL, 
    IFA_BROADCAST, 
    IFA_ANYCAST, 
    IFA_CACHEINFO, 
    IFA_MULTICAST, 
    __IFA_MAX, 
};

對於INET6 RTM_GETADDR請求內核IFA_ADDRESS迴應 -

nla_put(skb, IFA_ADDRESS, 16, &ifa->addr)

來源

2016-09-23 16:02:52 Chu

使用netlink的ipv6本地地址

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