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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 | /* * 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; } |