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-rw-r--r--tools/testing/selftests/proc/fd-001-lookup.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/fd-001-lookup.c b/tools/testing/selftests/proc/fd-001-lookup.c
new file mode 100644
index 0000000000..60d7948e71
--- /dev/null
+++ b/tools/testing/selftests/proc/fd-001-lookup.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+// Test /proc/*/fd lookup.
+
+#undef NDEBUG
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "proc.h"
+
+/* lstat(2) has more "coverage" in case non-symlink pops up somehow. */
+static void test_lookup_pass(const char *pathname)
+{
+ struct stat st;
+ ssize_t rv;
+
+ memset(&st, 0, sizeof(struct stat));
+ rv = lstat(pathname, &st);
+ assert(rv == 0);
+ assert(S_ISLNK(st.st_mode));
+}
+
+static void test_lookup_fail(const char *pathname)
+{
+ struct stat st;
+ ssize_t rv;
+
+ rv = lstat(pathname, &st);
+ assert(rv == -1 && errno == ENOENT);
+}
+
+static void test_lookup(unsigned int fd)
+{
+ char buf[64];
+ unsigned int c;
+ unsigned int u;
+ int i;
+
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd);
+ test_lookup_pass(buf);
+
+ /* leading junk */
+ for (c = 1; c <= 255; c++) {
+ if (c == '/')
+ continue;
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%c%u", c, fd);
+ test_lookup_fail(buf);
+ }
+
+ /* trailing junk */
+ for (c = 1; c <= 255; c++) {
+ if (c == '/')
+ continue;
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u%c", fd, c);
+ test_lookup_fail(buf);
+ }
+
+ for (i = INT_MIN; i < INT_MIN + 1024; i++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
+ test_lookup_fail(buf);
+ }
+ for (i = -1024; i < 0; i++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
+ test_lookup_fail(buf);
+ }
+ for (u = INT_MAX - 1024; u <= (unsigned int)INT_MAX + 1024; u++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
+ test_lookup_fail(buf);
+ }
+ for (u = UINT_MAX - 1024; u != 0; u++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
+ test_lookup_fail(buf);
+ }
+
+
+}
+
+int main(void)
+{
+ struct dirent *de;
+ unsigned int fd, target_fd;
+
+ if (unshare(CLONE_FILES) == -1)
+ return 1;
+
+ /* Wipe fdtable. */
+ do {
+ DIR *d;
+
+ d = opendir("/proc/self/fd");
+ if (!d)
+ return 1;
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, "."));
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, ".."));
+next:
+ de = xreaddir(d);
+ if (de) {
+ unsigned long long fd_ull;
+ unsigned int fd;
+ char *end;
+
+ assert(de->d_type == DT_LNK);
+
+ fd_ull = xstrtoull(de->d_name, &end);
+ assert(*end == '\0');
+ assert(fd_ull == (unsigned int)fd_ull);
+
+ fd = fd_ull;
+ if (fd == dirfd(d))
+ goto next;
+ close(fd);
+ }
+
+ closedir(d);
+ } while (de);
+
+ /* Now fdtable is clean. */
+
+ fd = open("/", O_PATH|O_DIRECTORY);
+ assert(fd == 0);
+ test_lookup(fd);
+ close(fd);
+
+ /* Clean again! */
+
+ fd = open("/", O_PATH|O_DIRECTORY);
+ assert(fd == 0);
+ /* Default RLIMIT_NOFILE-1 */
+ target_fd = 1023;
+ while (target_fd > 0) {
+ if (dup2(fd, target_fd) == target_fd)
+ break;
+ target_fd /= 2;
+ }
+ assert(target_fd > 0);
+ close(fd);
+ test_lookup(target_fd);
+ close(target_fd);
+
+ return 0;
+}