84 lines
1.8 KiB
C
84 lines
1.8 KiB
C
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/*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*
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* Copyright (c) 2018 Marcelo Tosatti <mtosatti@redhat.com>
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* Open a socket, and enable timestamping on it.
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*
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* This is to avoid Chrony from changing timestamping
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* user count from 0->1 and vice-versa, causing
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* static key enable/disable IPIs.
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*
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*/
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <ifaddrs.h>
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#include <linux/errqueue.h>
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#include <linux/ethtool.h>
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#include <linux/net_tstamp.h>
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#include <linux/sockios.h>
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#include <net/if.h>
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#include <stdio.h>
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#include <unistd.h>
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#include <stdlib.h>
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#include <sys/stat.h>
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#include <string.h>
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#include <fcntl.h>
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#include <errno.h>
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int main (void)
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{
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int option = SOF_TIMESTAMPING_OPT_TX_SWHW;
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int sock_fd;
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int ret;
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int pid_fd;
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pid_t pid;
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char buf[50];
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/* open a datagram socket */
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sock_fd = socket(AF_INET, SOCK_DGRAM, 0);
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if (sock_fd < 0) {
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printf("Error opening the socket\n");
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return 0;
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}
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/* set the timestamping option
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* this is to trigger the IPIs that notify all cpus of the change
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*/
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if (setsockopt(sock_fd, SOL_SOCKET, SO_TIMESTAMP, &option, sizeof (option)) < 0) {
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printf("Could not enable timestamping option %x", (unsigned int)option);
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close(sock_fd);
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return 0;
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}
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/* dameonize our task */
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ret = daemon(0, 0);
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if (ret == -1) {
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perror("daemon");
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exit(0);
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}
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/* write our pid file to make systemd happy */
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pid_fd = open("/run/rt-entsk.pid", O_RDWR|O_CREAT|O_TRUNC, 0644);
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if (pid_fd < 0) {
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perror("open of /run/rt-entsk.pid failed:");
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exit(errno);
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}
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pid = getpid();
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sprintf(buf, "%d\n", pid);
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ret = write(pid_fd, buf, strlen(buf));
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if (ret == -1) {
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perror("write");
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exit(1);
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}
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close(pid_fd);
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/* now just pause forever */
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while (1) {
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pause();
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}
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}
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