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| 1 | +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
| 2 | + |
| 3 | +/*** |
| 4 | + This file is part of systemd. |
| 5 | +
|
| 6 | + Copyright 2010 Lennart Poettering |
| 7 | +
|
| 8 | + systemd is free software; you can redistribute it and/or modify it |
| 9 | + under the terms of the GNU Lesser General Public License as published by |
| 10 | + the Free Software Foundation; either version 2.1 of the License, or |
| 11 | + (at your option) any later version. |
| 12 | +
|
| 13 | + systemd is distributed in the hope that it will be useful, but |
| 14 | + WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 16 | + Lesser General Public License for more details. |
| 17 | +
|
| 18 | + You should have received a copy of the GNU Lesser General Public License |
| 19 | + along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| 20 | +***/ |
| 21 | + |
| 22 | +#include <sys/ioctl.h> |
| 23 | +#include <sys/stat.h> |
| 24 | +#include <linux/fs.h> |
| 25 | + |
| 26 | +#include "chattr-util.h" |
| 27 | +#include "fd-util.h" |
| 28 | +#include "util.h" |
| 29 | + |
| 30 | +int chattr_fd(int fd, unsigned value, unsigned mask) { |
| 31 | + unsigned old_attr, new_attr; |
| 32 | + struct stat st; |
| 33 | + |
| 34 | + assert(fd >= 0); |
| 35 | + |
| 36 | + if (fstat(fd, &st) < 0) |
| 37 | + return -errno; |
| 38 | + |
| 39 | + /* Explicitly check whether this is a regular file or |
| 40 | + * directory. If it is anything else (such as a device node or |
| 41 | + * fifo), then the ioctl will not hit the file systems but |
| 42 | + * possibly drivers, where the ioctl might have different |
| 43 | + * effects. Notably, DRM is using the same ioctl() number. */ |
| 44 | + |
| 45 | + if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) |
| 46 | + return -ENOTTY; |
| 47 | + |
| 48 | + if (mask == 0) |
| 49 | + return 0; |
| 50 | + |
| 51 | + if (ioctl(fd, FS_IOC_GETFLAGS, &old_attr) < 0) |
| 52 | + return -errno; |
| 53 | + |
| 54 | + new_attr = (old_attr & ~mask) | (value & mask); |
| 55 | + if (new_attr == old_attr) |
| 56 | + return 0; |
| 57 | + |
| 58 | + if (ioctl(fd, FS_IOC_SETFLAGS, &new_attr) < 0) |
| 59 | + return -errno; |
| 60 | + |
| 61 | + return 1; |
| 62 | +} |
| 63 | + |
| 64 | +int chattr_path(const char *p, unsigned value, unsigned mask) { |
| 65 | + _cleanup_close_ int fd = -1; |
| 66 | + |
| 67 | + assert(p); |
| 68 | + |
| 69 | + if (mask == 0) |
| 70 | + return 0; |
| 71 | + |
| 72 | + fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); |
| 73 | + if (fd < 0) |
| 74 | + return -errno; |
| 75 | + |
| 76 | + return chattr_fd(fd, value, mask); |
| 77 | +} |
| 78 | + |
| 79 | +int read_attr_fd(int fd, unsigned *ret) { |
| 80 | + struct stat st; |
| 81 | + |
| 82 | + assert(fd >= 0); |
| 83 | + |
| 84 | + if (fstat(fd, &st) < 0) |
| 85 | + return -errno; |
| 86 | + |
| 87 | + if (!S_ISDIR(st.st_mode) && !S_ISREG(st.st_mode)) |
| 88 | + return -ENOTTY; |
| 89 | + |
| 90 | + if (ioctl(fd, FS_IOC_GETFLAGS, ret) < 0) |
| 91 | + return -errno; |
| 92 | + |
| 93 | + return 0; |
| 94 | +} |
| 95 | + |
| 96 | +int read_attr_path(const char *p, unsigned *ret) { |
| 97 | + _cleanup_close_ int fd = -1; |
| 98 | + |
| 99 | + assert(p); |
| 100 | + assert(ret); |
| 101 | + |
| 102 | + fd = open(p, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW); |
| 103 | + if (fd < 0) |
| 104 | + return -errno; |
| 105 | + |
| 106 | + return read_attr_fd(fd, ret); |
| 107 | +} |
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