c++ - 使用 libnl-3-route "Invalid input data or parameter"添加路由

Question

我正在尝试使用 libnl-3-routing 添加路由(内核 2.6.32-57)。我使用文档:

1. Netlink library
2. Netlink routing

但是路由章节是空的...;)

问题是内核响应“无效的输入数据或参数”。我已经使用 netlink 做了一些测试，如果我设置以下属性，我可以添加一条路由:

1. 界面索引
2. 目标地址
3. 网关地址

4. 掩码

       int ret = 0;
       // Create the route.
       struct rtnl_route* rulesRoute = rtnl_route_alloc();
       rtnl_route_set_iif(rulesRoute, AF_INET); // IPV4
   
       // Set parameters.
       rtnl_route_set_scope(rulesRoute, RT_SCOPE_UNIVERSE);
       rtnl_route_set_table(rulesRoute, RT_TABLE_MAIN);
       rtnl_route_set_protocol(rulesRoute, RTPROT_STATIC);
       uint8_t maskTest = 16;
       rtnl_route_set_scope(rulesRoute, maskTest);
   
       // Set the destination.
       char destinationAddr[] = "0.0.0.0";
       nl_addr* dstAddr = nl_addr_build(AF_INET, destinationAddr, 8);
       ret = rtnl_route_set_dst(rulesRoute, dstAddr);
       if (ret != 0)
           std::cout << "Error in setting destination route: " << nl_geterror(ret) << std::endl;
   
       // Set the next hop.
       struct rtnl_nexthop* route_nexthop = rtnl_route_nh_alloc();
       char gatewayAddr[] = "10.110.0.240";
       nl_addr* gatewAddr = nl_addr_build(AF_INET, gatewayAddr, 12);
       rtnl_route_nh_set_gateway(route_nexthop, gatewAddr);
       rtnl_route_nh_set_ifindex(route_nexthop, 2);
       rtnl_route_add_nexthop(rulesRoute, route_nexthop);
       ret = rtnl_route_add(m_nlSocket, rulesRoute, 0);
       if (ret != 0)
           std::cout << "Kernel response:" << nl_geterror(ret) << std::endl;
   

我添加我的路由表以获取信息:

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
10.110.0.0      0.0.0.0         255.255.255.0   U     1      0        0 eth3
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth3
0.0.0.0         10.110.0.1      0.0.0.0         UG    0      0        0 eth3

感谢您帮助解决此问题

Answer 1

问题来自于函数nl_addr_build的错误使用。

替换为 nl_addr_parse() 即可。

nl_addr_build:解析二进制地址

nl_addr_parse :解析 char* addr，如“10.10.1.10”