xref: /aosp_15_r20/external/toybox/toys/pending/useradd.c (revision cf5a6c84e2b8763fc1a7db14496fd4742913b199)
1 /* useradd.c - add a new user
2  *
3  * Copyright 2013 Ashwini Kumar <[email protected]>
4  * Copyright 2013 Kyungwan Han <[email protected]>
5  *
6  * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/useradd.html
7 
8 USE_USERADD(NEWTOY(useradd, "<1>2u#<0G:s:g:h:SDH", TOYFLAG_NEEDROOT|TOYFLAG_UMASK|TOYFLAG_SBIN))
9 USE_USERADD(OLDTOY(adduser, useradd, TOYFLAG_NEEDROOT|TOYFLAG_UMASK|TOYFLAG_SBIN))
10 
11 config USERADD
12   bool "useradd"
13   default n
14   help
15     usage: useradd [-SDH] [-h DIR] [-s SHELL] [-G GRP] [-g NAME] [-u UID] USER [GROUP]
16 
17     Create new user, or add USER to GROUP
18 
19     -D       Don't assign a password
20     -g NAME  Real name
21     -G GRP   Add user to existing group
22     -h DIR   Home directory
23     -H       Don't create home directory
24     -s SHELL Login shell
25     -S       Create a system user
26     -u UID   User id
27 */
28 
29 #define FOR_useradd
30 #include "toys.h"
31 
GLOBALS(char * dir;char * gecos;char * shell;char * u_grp;long uid;long gid;)32 GLOBALS(
33   char *dir;
34   char *gecos;
35   char *shell;
36   char *u_grp;
37   long uid;
38 
39   long gid;
40 )
41 
42 // TODO user exists error
43 void useradd_main(void)
44 {
45   char *s = *toys.optargs, *entry;
46   struct passwd pwd;
47 
48   // Act like groupadd?
49   if (toys.optc == 2) {
50     if (toys.optflags) help_exit("options with USER GROUP");
51     xexec((char *[]){"groupadd", toys.optargs[0], toys.optargs[1], 0});
52   }
53 
54   // Sanity check user to add
55   if (s[strcspn(s, ":/\n")] || strlen(s) > LOGIN_NAME_MAX)
56     error_exit("bad username");
57   // race condition: two adds at same time?
58   if (getpwnam(s)) error_exit("'%s' in use", s);
59 
60   // Add a new group to the system, if UID is given then that is validated
61   // to be free, else a free UID is choosen by self.
62   // SYSTEM IDs are considered in the range 100 ... 999
63   // add_user(), add a new entry in /etc/passwd, /etc/shadow files
64 
65   pwd.pw_name = s;
66   pwd.pw_passwd = "x";
67   pwd.pw_gecos = TT.gecos ? TT.gecos : "Linux User,";
68   pwd.pw_dir = TT.dir ? TT.dir : xmprintf("/home/%s", *toys.optargs);
69 
70   if (!TT.shell) {
71     TT.shell = getenv("SHELL");
72 
73     if (!TT.shell) {
74       struct passwd *pw = getpwuid(getuid());
75 
76       if (pw && pw->pw_shell && *pw->pw_shell) TT.shell = xstrdup(pw->pw_shell);
77       else TT.shell = "/bin/sh";
78     }
79   }
80   pwd.pw_shell = TT.shell;
81 
82   if (toys.optflags & FLAG_u) {
83     if (TT.uid > INT_MAX) error_exit("bad uid");
84     if (getpwuid(TT.uid)) error_exit("uid '%ld' in use", TT.uid);
85   } else {
86     if (toys.optflags & FLAG_S) TT.uid = CFG_TOYBOX_UID_SYS;
87     else TT.uid = CFG_TOYBOX_UID_USR;
88     //find unused uid
89     while (getpwuid(TT.uid)) TT.uid++;
90   }
91   pwd.pw_uid = TT.uid;
92 
93   if (toys.optflags & FLAG_G) TT.gid = xgetgrnam(TT.u_grp)->gr_gid;
94   else {
95     // Set the GID for the user, if not specified
96     if (toys.optflags & FLAG_S) TT.gid = CFG_TOYBOX_UID_SYS;
97     else TT.gid = CFG_TOYBOX_UID_USR;
98     if (getgrnam(pwd.pw_name)) error_exit("group '%s' in use", pwd.pw_name);
99     //find unused gid
100     while (getgrgid(TT.gid)) TT.gid++;
101   }
102   pwd.pw_gid = TT.gid;
103 
104   // Create a new group for user
105   if (!(toys.optflags & FLAG_G)) {
106     char *s = xmprintf("-g%ld", (long)pwd.pw_gid);
107 
108     if (xrun((char *[]){"groupadd", *toys.optargs, s, 0}))
109       error_msg("addgroup -g%ld fail", (long)pwd.pw_gid);
110     free(s);
111   }
112 
113   /*add user to system
114    * 1. add an entry to /etc/passwd and /etcshadow file
115    * 2. Copy /etc/skel dir contents to use home dir
116    * 3. update the user passwd by running 'passwd' utility
117    */
118 
119   // 1. add an entry to /etc/passwd and /etc/shadow file
120   entry = xmprintf("%s:%s:%ld:%ld:%s:%s:%s", pwd.pw_name, pwd.pw_passwd,
121       (long)pwd.pw_uid, (long)pwd.pw_gid, pwd.pw_gecos, pwd.pw_dir,
122       pwd.pw_shell);
123   update_password("/etc/passwd", pwd.pw_name, entry, 0);
124   free(entry);
125 
126   if (toys.optflags & FLAG_S)
127   entry = xmprintf("%s:!!:%u::::::", pwd.pw_name,
128       (unsigned)(time(NULL))/(24*60*60)); //passwd is not set initially
129   else entry = xmprintf("%s:!!:%u:0:99999:7:::", pwd.pw_name,
130             (unsigned)(time(0))/(24*60*60)); //passwd is not set initially
131   update_password("/etc/shadow", pwd.pw_name, entry, 0);
132   free(entry);
133 
134   // create home dir & copy skel dir to home
135   if (!(toys.optflags & (FLAG_S|FLAG_H))) {
136     char *skel = "/etc/skel", *p = pwd.pw_dir;
137 
138     // Copy and change ownership
139     if (access(p, F_OK)) {
140       if (!access(skel, R_OK))
141         toys.exitval = xrun((char *[]){"cp", "-R", skel, p, 0});
142       else toys.exitval = xrun((char *[]){"mkdir", "-p", p, 0});
143       if (!toys.exitval)
144         toys.exitval |= xrun((char *[]){"chown", "-R",
145           xmprintf("%lu:%lu", TT.uid, TT.gid), p, 0});
146       wfchmodat(AT_FDCWD, p, 0700);
147     } else fprintf(stderr, "'%s' exists, not copying '%s'", p, skel);
148   }
149 
150   //3. update the user passwd by running 'passwd' utility
151   if (!(toys.optflags & FLAG_D))
152     if (xrun((char *[]){"passwd", pwd.pw_name, 0})) error_exit("passwd");
153 
154   if (toys.optflags & FLAG_G) {
155     /*add user to the existing group, invoke addgroup command */
156     if (xrun((char *[]){"groupadd", *toys.optargs, TT.u_grp, 0}))
157       error_exit("groupadd");
158   }
159 }
160