94 lines
2.6 KiB
C
94 lines
2.6 KiB
C
// Copyright 2020 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <err.h>
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#include <fcntl.h>
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#include <string.h>
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#include <sys/stat.h>
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#include <sys/types.h>
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#include <unistd.h>
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// Basic test for linkat(2). Syscall tests requires CAP_DAC_READ_SEARCH and it
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// cannot use tricks like userns as root. For this reason, run a basic link test
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// to ensure some coverage.
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int main(int argc, char** argv) {
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const char kOldPath[] = "old.txt";
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int fd = open(kOldPath, O_RDWR | O_CREAT | O_TRUNC, 0600);
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if (fd < 0) {
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errx(1, "open(%s) failed", kOldPath);
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}
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const char kData[] = "some random content";
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if (write(fd, kData, sizeof(kData)) < 0) {
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err(1, "write failed");
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}
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close(fd);
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struct stat old_stat;
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if (stat(kOldPath, &old_stat)) {
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errx(1, "stat(%s) failed", kOldPath);
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}
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const char kNewPath[] = "new.txt";
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if (link(kOldPath, kNewPath)) {
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errx(1, "link(%s, %s) failed", kOldPath, kNewPath);
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}
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struct stat new_stat;
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if (stat(kNewPath, &new_stat)) {
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errx(1, "stat(%s) failed", kNewPath);
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}
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// Check that files are the same.
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if (old_stat.st_dev != new_stat.st_dev) {
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errx(1, "files st_dev is different, want: %lu, got: %lu", old_stat.st_dev,
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new_stat.st_dev);
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}
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if (old_stat.st_ino != new_stat.st_ino) {
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errx(1, "files st_ino is different, want: %lu, got: %lu", old_stat.st_ino,
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new_stat.st_ino);
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}
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// Check that link count is correct.
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if (new_stat.st_nlink != old_stat.st_nlink + 1) {
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errx(1, "wrong nlink, want: %lu, got: %lu", old_stat.st_nlink + 1,
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new_stat.st_nlink);
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}
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// Check taht contents are the same.
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fd = open(kNewPath, O_RDONLY);
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if (fd < 0) {
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errx(1, "open(%s) failed", kNewPath);
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}
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char buf[sizeof(kData)] = {};
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if (read(fd, buf, sizeof(buf)) < 0) {
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err(1, "read failed");
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}
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close(fd);
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if (strcmp(buf, kData) != 0) {
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errx(1, "file content mismatch: %s", buf);
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}
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// Cleanup.
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if (unlink(kNewPath)) {
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errx(1, "unlink(%s) failed", kNewPath);
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}
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if (unlink(kOldPath)) {
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errx(1, "unlink(%s) failed", kOldPath);
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}
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// Success!
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return 0;
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}
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