diff options
Diffstat (limited to 'tools/testing/selftests/proc/fd-001-lookup.c')
| -rw-r--r-- | tools/testing/selftests/proc/fd-001-lookup.c | 168 |
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 0000000000000..a2010dfb21104 --- /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. +#define _GNU_SOURCE +#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; +} |