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Serenity Operating System
1/*
2 * Copyright (c) 2019-2020, Sergey Bugaev <bugaevc@serenityos.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include <AK/JsonArray.h>
28#include <AK/JsonObject.h>
29#include <AK/JsonValue.h>
30#include <AK/Optional.h>
31#include <LibCore/ArgsParser.h>
32#include <LibCore/File.h>
33#include <fcntl.h>
34#include <stdio.h>
35#include <string.h>
36#include <unistd.h>
37
38int parse_options(const StringView& options)
39{
40 int flags = 0;
41 Vector<StringView> parts = options.split_view(',');
42 for (auto& part : parts) {
43 if (part == "defaults")
44 continue;
45 else if (part == "nodev")
46 flags |= MS_NODEV;
47 else if (part == "noexec")
48 flags |= MS_NOEXEC;
49 else if (part == "nosuid")
50 flags |= MS_NOSUID;
51 else if (part == "bind")
52 flags |= MS_BIND;
53 else
54 fprintf(stderr, "Ignoring invalid option: %s\n", String(part).characters());
55 }
56 return flags;
57}
58
59bool is_source_none(const char* source)
60{
61 return !strcmp("none", source);
62}
63
64int get_source_fd(const char* source)
65{
66 if (is_source_none(source))
67 return -1;
68 int fd = open(source, O_RDWR);
69 if (fd < 0)
70 fd = open(source, O_RDONLY);
71 if (fd < 0) {
72 int saved_errno = errno;
73 auto message = String::format("Failed to open: %s\n", source);
74 errno = saved_errno;
75 perror(message.characters());
76 }
77 return fd;
78}
79
80bool mount_all()
81{
82 // Mount all filesystems listed in /etc/fstab.
83 dbg() << "Mounting all filesystems...";
84
85 auto fstab = Core::File::construct("/etc/fstab");
86 if (!fstab->open(Core::IODevice::OpenMode::ReadOnly)) {
87 fprintf(stderr, "Failed to open /etc/fstab: %s\n", fstab->error_string());
88 return false;
89 }
90
91 bool all_ok = true;
92 while (fstab->can_read_line()) {
93 ByteBuffer buffer = fstab->read_line(1024);
94 StringView line_view = (const char*)buffer.data();
95
96 // Trim the trailing newline, if any.
97 if (line_view.length() > 0 && line_view[line_view.length() - 1] == '\n')
98 line_view = line_view.substring_view(0, line_view.length() - 1);
99 String line = line_view;
100
101 // Skip comments and blank lines.
102 if (line.is_empty() || line.starts_with("#"))
103 continue;
104
105 Vector<String> parts = line.split('\t');
106 if (parts.size() < 3) {
107 fprintf(stderr, "Invalid fstab entry: %s\n", line.characters());
108 all_ok = false;
109 continue;
110 }
111
112 const char* mountpoint = parts[1].characters();
113 const char* fstype = parts[2].characters();
114 int flags = parts.size() >= 4 ? parse_options(parts[3]) : 0;
115
116 if (strcmp(mountpoint, "/") == 0) {
117 dbg() << "Skipping mounting root";
118 continue;
119 }
120
121 const char* filename = parts[0].characters();
122
123 int fd = get_source_fd(filename);
124
125 dbg() << "Mounting " << filename << "(" << fstype << ")"
126 << " on " << mountpoint;
127 int rc = mount(fd, mountpoint, fstype, flags);
128 if (rc != 0) {
129 fprintf(stderr, "Failed to mount %s (FD: %d) (%s) on %s: %s\n", filename, fd, fstype, mountpoint, strerror(errno));
130 all_ok = false;
131 continue;
132 }
133 }
134
135 return all_ok;
136}
137
138bool print_mounts()
139{
140 // Output info about currently mounted filesystems.
141 auto df = Core::File::construct("/proc/df");
142 if (!df->open(Core::IODevice::ReadOnly)) {
143 fprintf(stderr, "Failed to open /proc/df: %s\n", df->error_string());
144 return false;
145 }
146
147 auto content = df->read_all();
148 auto json = JsonValue::from_string(content).as_array();
149
150 json.for_each([](auto& value) {
151 auto fs_object = value.as_object();
152 auto class_name = fs_object.get("class_name").to_string();
153 auto mount_point = fs_object.get("mount_point").to_string();
154 auto device = fs_object.get("device").as_string_or(class_name);
155 auto readonly = fs_object.get("readonly").to_bool();
156 auto mount_flags = fs_object.get("mount_flags").to_int();
157
158 printf("%s on %s type %s (", device.characters(), mount_point.characters(), class_name.characters());
159
160 if (readonly)
161 printf("ro");
162 else
163 printf("rw");
164
165 if (mount_flags & MS_NODEV)
166 printf(",nodev");
167 if (mount_flags & MS_NOEXEC)
168 printf(",noexec");
169 if (mount_flags & MS_NOSUID)
170 printf(",nosuid");
171 if (mount_flags & MS_BIND)
172 printf(",bind");
173
174 printf(")\n");
175 });
176
177 return true;
178}
179
180int main(int argc, char** argv)
181{
182 const char* source = nullptr;
183 const char* mountpoint = nullptr;
184 const char* fs_type = nullptr;
185 const char* options = nullptr;
186 bool should_mount_all = false;
187
188 Core::ArgsParser args_parser;
189 args_parser.add_positional_argument(source, "Source path", "source", Core::ArgsParser::Required::No);
190 args_parser.add_positional_argument(mountpoint, "Mount point", "mountpoint", Core::ArgsParser::Required::No);
191 args_parser.add_option(fs_type, "File system type", nullptr, 't', "fstype");
192 args_parser.add_option(options, "Mount options", nullptr, 'o', "options");
193 args_parser.add_option(should_mount_all, "Mount all file systems listed in /etc/fstab", nullptr, 'a');
194 args_parser.parse(argc, argv);
195
196 if (should_mount_all) {
197 return mount_all() ? 0 : 1;
198 }
199
200 if (!source && !mountpoint)
201 return print_mounts() ? 0 : 1;
202
203 if (source && mountpoint) {
204 if (!fs_type)
205 fs_type = "ext2";
206 int flags = options ? parse_options(options) : 0;
207
208 int fd = get_source_fd(source);
209
210 if (mount(fd, mountpoint, fs_type, flags) < 0) {
211 perror("mount");
212 return 1;
213 }
214 return 0;
215 }
216
217 args_parser.print_usage(stderr, argv[0]);
218 return 1;
219}