/src/sudo/lib/iolog/iolog_openat.c
Line | Count | Source (jump to first uncovered line) |
1 | | /* |
2 | | * SPDX-License-Identifier: ISC |
3 | | * |
4 | | * Copyright (c) 2009-2021 Todd C. Miller <Todd.Miller@sudo.ws> |
5 | | * |
6 | | * Permission to use, copy, modify, and distribute this software for any |
7 | | * purpose with or without fee is hereby granted, provided that the above |
8 | | * copyright notice and this permission notice appear in all copies. |
9 | | * |
10 | | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
11 | | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
12 | | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
13 | | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
14 | | * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
15 | | * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
16 | | * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
17 | | */ |
18 | | |
19 | | /* |
20 | | * This is an open source non-commercial project. Dear PVS-Studio, please check it. |
21 | | * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com |
22 | | */ |
23 | | |
24 | | #include <config.h> |
25 | | |
26 | | #include <sys/stat.h> |
27 | | #include <stdio.h> |
28 | | #include <stdlib.h> |
29 | | #ifdef HAVE_STDBOOL_H |
30 | | # include <stdbool.h> |
31 | | #else |
32 | | # include "compat/stdbool.h" |
33 | | #endif |
34 | | #include <errno.h> |
35 | | #include <fcntl.h> |
36 | | #include <unistd.h> |
37 | | |
38 | | #include "sudo_compat.h" |
39 | | #include "sudo_debug.h" |
40 | | #include "sudo_fatal.h" |
41 | | #include "sudo_gettext.h" |
42 | | #include "sudo_iolog.h" |
43 | | #include "sudo_util.h" |
44 | | |
45 | | /* |
46 | | * Wrapper for openat(2) that sets umask and retries as iolog_uid/iolog_gid |
47 | | * if openat(2) returns EACCES. |
48 | | */ |
49 | | int |
50 | | iolog_openat(int dfd, const char *path, int flags) |
51 | 843 | { |
52 | 843 | const mode_t iolog_filemode = iolog_get_file_mode(); |
53 | 843 | const mode_t iolog_dirmode = iolog_get_dir_mode(); |
54 | 843 | mode_t omask = S_IRWXG|S_IRWXO; |
55 | 843 | int fd; |
56 | 843 | debug_decl(iolog_openat, SUDO_DEBUG_UTIL); |
57 | | |
58 | 843 | if (ISSET(flags, O_CREAT)) { |
59 | | /* umask must not be more restrictive than the file modes. */ |
60 | 0 | omask = umask(ACCESSPERMS & ~(iolog_filemode|iolog_dirmode)); |
61 | 0 | } |
62 | 843 | fd = openat(dfd, path, flags, iolog_filemode); |
63 | 843 | if (fd == -1 && errno == EACCES) { |
64 | | /* Enable write bit if it is missing. */ |
65 | 0 | struct stat sb; |
66 | 0 | if (fstatat(dfd, path, &sb, 0) == 0) { |
67 | 0 | mode_t write_bits = iolog_filemode & (S_IWUSR|S_IWGRP|S_IWOTH); |
68 | 0 | if ((sb.st_mode & write_bits) != write_bits) { |
69 | 0 | if (fchmodat(dfd, path, iolog_filemode, 0) == 0) |
70 | 0 | fd = openat(dfd, path, flags, iolog_filemode); |
71 | 0 | } |
72 | 0 | } |
73 | 0 | } |
74 | 843 | if (fd == -1 && errno == EACCES) { |
75 | | /* Try again as the I/O log owner (for NFS). */ |
76 | 0 | if (iolog_swapids(false)) { |
77 | 0 | fd = openat(dfd, path, flags, iolog_filemode); |
78 | 0 | if (!iolog_swapids(true)) { |
79 | | /* iolog_swapids() warns on error. */ |
80 | 0 | if (fd != -1) { |
81 | 0 | close(fd); |
82 | 0 | fd = -1; |
83 | 0 | } |
84 | 0 | } |
85 | 0 | } |
86 | 0 | } |
87 | 843 | if (ISSET(flags, O_CREAT)) |
88 | 0 | umask(omask); |
89 | 843 | debug_return_int(fd); |
90 | 843 | } |