这个典型的“route add default gw IP”程序给我错误:
SIOCADDRT 失败:设备的 ioctl 不合适
我执行了 ifconfig 来验证接口(interface)名称。 有没有办法列出适合我的设备的所有 ioctl?
int main(char** args) {
int sockfd;
struct rtentry route;
struct sockaddr_in *addr;
int err = 0;
// create the socket
if(sockfd = socket(AF_INET, SOCK_DGRAM, 0)<0){
perror("socket");
exit(1);
}
memset(&route, 0, sizeof(route));
addr = (struct sockaddr_in*) &route.rt_gateway;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr("192.168.10.1");
addr = (struct sockaddr_in*) &route.rt_dst;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = INADDR_ANY;
addr = (struct sockaddr_in*) &route.rt_genmask;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = INADDR_ANY;
route.rt_dev = "eth0";
route.rt_flags = RTF_UP | RTF_GATEWAY;
route.rt_metric = 0;
if ((err = ioctl(sockfd, SIOCADDRT, &route)) != 0) {
perror("SIOCADDRT failed");
exit(1);
}
}
将代码更改为后出现新错误:
addr = (struct sockaddr_in*) &route.rt_gateway;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr("192.168.10.1");
addr = (struct sockaddr_in*) &route.rt_dst;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr("192.168.10.3");
addr = (struct sockaddr_in*) &route.rt_genmask;
addr->sin_family = AF_INET;
addr->sin_addr.s_addr = inet_addr("255.255.255.0");
gdb 输出:
37 if ((err = ioctl(sockfd, SIOCADDRT, &route)) != 0) {
(gdb) p route
$1 = {rt_pad1 = 0, rt_dst = {sa_family = 2, sa_data = "\000\000\300\250\n\003\000\000\000\000\000\000\000"},
rt_gateway = {sa_family = 2, sa_data = "\000\000\300\250\n\001\000\000\000\000\000\000\000"},
rt_genmask = {sa_family = 2, sa_data = "\000\000\377\377\377\000\000\000\000\000\000\000\000"},
rt_flags = 3, rt_pad2 = 0, rt_pad3 = 0, rt_tos = 0 '\000', rt_class = 0 '\000', rt_pad4 = {0, 0, 0},
rt_metric = 0, rt_dev = 0x4008af "em1", rt_mtu = 0, rt_window = 0, rt_irtt = 0}
(gdb) n
38 perror("SIOCADDRT failed");
(gdb)
SIOCADDRT failed: Invalid argument
最佳答案
我猜错误在这里:
// create the socket
if(sockfd = socket(AF_INET, SOCK_DGRAM, 0)<0)
表达式socket(AF_INET, SOCK_DGRAM, 0)<0
在分配之前进行评估。发生这种情况是因为赋值运算符的优先级低于函数调用和比较。您可以在这篇维基百科文章中阅读更多相关信息:
所以你真正拥有的是:
// create the socket
if(sockfd = (socket(AF_INET, SOCK_DGRAM, 0)<0))
计算结果为:
// create the socket
if(sockfd = 0)
所以你正在尝试执行 ioctl()
关于无效的文件描述符。
将赋值放入括号中或将表达式移出条件,如下所示:
// create the socket
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sockfd < 0)
顺便说一句,如果您通过 -Wall
,GCC 或 Clang 应该会检测到它。选项。
关于c - 路由设置 : SIOCADDRT failed: Inappropriate ioctl for device,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/25000609/