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Serenity Operating System
1/*
2 * Copyright (c) 2020, Fei Wu <f.eiwu@yahoo.com>
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/String.h>
28#include <AK/StringBuilder.h>
29#include <LibCore/ArgsParser.h>
30#include <ctype.h>
31#include <dirent.h>
32#include <errno.h>
33#include <pwd.h>
34#include <stdio.h>
35#include <stdlib.h>
36#include <string.h>
37#include <sys/stat.h>
38#include <sys/types.h>
39#include <sys/wait.h>
40#include <unistd.h>
41
42int main(int argc, char** argv)
43{
44 const char* username = nullptr;
45 bool remove_home = false;
46
47 Core::ArgsParser args_parser;
48 args_parser.add_option(remove_home, "Remove home directory", "remove", 'r');
49 args_parser.add_positional_argument(username, "Login user identity (username)", "login");
50 args_parser.parse(argc, argv);
51
52 char temp_filename[] = "/etc/passwd.XXXXXX";
53 auto fd = mkstemp(temp_filename);
54 if (fd == -1) {
55 perror("failed to create temporary file");
56 return 1;
57 }
58
59 FILE* temp_file = fdopen(fd, "w");
60 if (!temp_file) {
61 perror("fdopen");
62 if (unlink(temp_filename) < 0) {
63 perror("unlink");
64 }
65
66 return 1;
67 }
68
69 bool user_exists = false;
70 String home_directory;
71
72 int rc = 0;
73 setpwent();
74 for (auto* pw = getpwent(); pw; pw = getpwent()) {
75 if (strcmp(pw->pw_name, username)) {
76 if (putpwent(pw, temp_file) != 0) {
77 perror("failed to put an entry in the temporary passwd file");
78 rc = 1;
79 break;
80 }
81 } else {
82 user_exists = true;
83 if (remove_home)
84 home_directory = pw->pw_dir;
85 }
86 }
87 endpwent();
88
89 if (fclose(temp_file)) {
90 perror("fclose");
91 if (!rc)
92 rc = 1;
93 }
94
95 if (rc == 0 && !user_exists) {
96 fprintf(stderr, "specified user doesn't exist\n");
97 rc = 6;
98 }
99
100 if (rc == 0 && chmod(temp_filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)) {
101 perror("chmod");
102 rc = 1;
103 }
104
105 if (rc == 0 && rename(temp_filename, "/etc/passwd") < 0) {
106 perror("failed to rename the temporary passwd file");
107 rc = 1;
108 }
109
110 if (rc) {
111 if (unlink(temp_filename) < 0) {
112 perror("unlink");
113 }
114 return rc;
115 }
116
117 if (remove_home) {
118 if (home_directory == "/") {
119 fprintf(stderr, "home directory is /, not deleted!\n");
120 return 12;
121 }
122
123 if (access(home_directory.characters(), F_OK) != -1) {
124 auto child = fork();
125
126 if (child < 0) {
127 perror("fork");
128 return 12;
129 }
130
131 if (!child) {
132 int rc = execl("/bin/rm", "rm", "-r", home_directory.characters(), nullptr);
133 ASSERT(rc < 0);
134 perror("execl");
135 exit(127);
136 }
137
138 int wstatus;
139 if (waitpid(child, &wstatus, 0) < 0) {
140 perror("waitpid");
141 return 12;
142 }
143 if (WEXITSTATUS(wstatus)) {
144 fprintf(stderr, "failed to remove the home directory\n");
145 return 12;
146 }
147 }
148 }
149
150 return 0;
151}