mirror of
https://git.kernel.org/pub/scm/network/iproute2/iproute2.git
synced 2024-12-12 11:13:29 +08:00
2bbc5b0726
Currently, if a non-root user attempts to run ip vrf exec a non-helpful error is returned: $ ip vrf exec mgmt bash Failed to mount cgroup2. Are CGROUPS enabled in your kernel? Only show the CGROUPS kernel hint for the ENODEV error and for the rest show the strerror for the errno. So now: $ ip/ip vrf exec mgmt bash Failed to mount cgroup2: Operation not permitted Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
152 lines
2.8 KiB
C
152 lines
2.8 KiB
C
/*
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* fs.c filesystem APIs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: David Ahern <dsa@cumulusnetworks.com>
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*
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*/
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <sys/socket.h>
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#include <sys/mount.h>
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#include <fcntl.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <limits.h>
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#include "utils.h"
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#define CGROUP2_FS_NAME "cgroup2"
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/* if not already mounted cgroup2 is mounted here for iproute2's use */
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#define MNT_CGRP2_PATH "/var/run/cgroup2"
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/* return mount path of first occurrence of given fstype */
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static char *find_fs_mount(const char *fs_to_find)
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{
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char path[4096];
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char fstype[128]; /* max length of any filesystem name */
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char *mnt = NULL;
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FILE *fp;
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fp = fopen("/proc/mounts", "r");
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if (!fp) {
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fprintf(stderr,
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"Failed to open mounts file: %s\n", strerror(errno));
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return NULL;
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}
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while (fscanf(fp, "%*s %4096s %127s %*s %*d %*d\n",
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path, fstype) == 2) {
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if (strcmp(fstype, fs_to_find) == 0) {
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mnt = strdup(path);
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break;
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}
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}
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fclose(fp);
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return mnt;
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}
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/* caller needs to free string returned */
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char *find_cgroup2_mount(void)
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{
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char *mnt = find_fs_mount(CGROUP2_FS_NAME);
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if (mnt)
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return mnt;
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mnt = strdup(MNT_CGRP2_PATH);
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if (!mnt) {
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fprintf(stderr, "Failed to allocate memory for cgroup2 path\n");
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return NULL;
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}
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if (make_path(mnt, 0755)) {
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fprintf(stderr, "Failed to setup vrf cgroup2 directory\n");
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free(mnt);
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return NULL;
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}
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if (mount("none", mnt, CGROUP2_FS_NAME, 0, NULL)) {
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/* EBUSY means already mounted */
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if (errno == EBUSY)
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goto out;
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if (errno == ENODEV) {
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fprintf(stderr,
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"Failed to mount cgroup2. Are CGROUPS enabled in your kernel?\n");
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} else {
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fprintf(stderr,
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"Failed to mount cgroup2: %s\n",
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strerror(errno));
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}
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free(mnt);
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return NULL;
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}
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out:
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return mnt;
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}
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int make_path(const char *path, mode_t mode)
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{
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char *dir, *delim;
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struct stat sbuf;
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int rc = -1;
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delim = dir = strdup(path);
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if (dir == NULL) {
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fprintf(stderr, "strdup failed copying path");
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return -1;
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}
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/* skip '/' -- it had better exist */
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if (*delim == '/')
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delim++;
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while (1) {
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delim = strchr(delim, '/');
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if (delim)
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*delim = '\0';
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if (stat(dir, &sbuf) != 0) {
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if (errno != ENOENT) {
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fprintf(stderr,
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"stat failed for %s: %s\n",
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dir, strerror(errno));
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goto out;
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}
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if (mkdir(dir, mode) != 0) {
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fprintf(stderr,
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"mkdir failed for %s: %s\n",
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dir, strerror(errno));
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goto out;
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}
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}
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if (delim == NULL)
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break;
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*delim = '/';
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delim++;
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if (*delim == '\0')
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break;
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}
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rc = 0;
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out:
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free(dir);
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return rc;
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}
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