Linux rtnetlink：未调用RTM_NEWQDISC的适当函数

Question

我试图通过RTNETLINK插座创建一个新的QDisk，然后遵循如何做到这一点。

我的程序打开一个NetLink套接字，将A sockaddr_nl 绑定到套接字，并发送包含RTNETLINK数据的消息。我将NLMSGHDR的类型设置为 rtm_newqdisc 创建一个新的QDisk，但是在调试内核后，事实证明适当的函数（ tc_modify_qdisc rtm_newqdisc 甚至都没有调用Sched/sch_api.c ）。实际上，没有任何函数任何错误。因此，我想我的消息结构是错误或不完整的。我无法通过阅读manpage来弄清楚。有人知道这里的问题是什么？

#include <stdio.h>
#include <asm/types.h>
#include <sys/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <sys/socket.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

struct data {
  struct nlmsghdr nl;
  struct tcmsg tc;
  struct rtattr rt;
};

int main() {
  int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
  if(fd == -1) {
      printf("Error in socket: %s\n", strerror(errno));
      return -1;
  }

  struct sockaddr_nl la;
  memset((void *)&la, 0, sizeof(struct sockaddr_nl));
  la.nl_family = AF_NETLINK;
  la.nl_pid = getpid();

  if(bind(fd, (struct sockaddr*)&la, sizeof(la)) == -1) {
    printf("Error in bind: %s\n", strerror(errno));
    return -1;
  }

  struct data d;
  memset((void *)&d, 0, sizeof(struct data));
  d.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
  d.nl.nlmsg_type = RTM_NEWQDISC;
  d.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP | NLM_F_CREATE | NLM_F_ACK;
  d.nl.nlmsg_seq = 0;
  d.nl.nlmsg_pid = 0;

  d.tc.tcm_family = 0;
  d.tc.tcm_ifindex = 0;
  d.tc.tcm_handle = 0;
  d.tc.tcm_parent = 0;
  d.tc.tcm_info = 0;

  d.rt.rta_type = TCA_UNSPEC;

  struct msghdr msg;
  memset((void *)&msg, 0, sizeof(struct msghdr));
  msg.msg_name = (void *)&la;
  msg.msg_namelen = sizeof(la);

  struct iovec iov;
  memset((void *)&iov, 0, sizeof(struct iovec));
  iov.iov_base = (void *)&d.nl;
  iov.iov_len = d.nl.nlmsg_len;

  msg.msg_iov = &iov;
  msg.msg_iovlen = 1;

  if(sendmsg(fd, &msg, 0) == -1) {
    printf("Error in sendmsg: %s\n", strerror(errno));
    return -1;
  }

  puts("success");
}

我的内核版本是5.17。先感谢您