1 /* id.c - print real and effective user and group IDs
2  *
3  * Copyright 2012 Sony Network Entertainment, Inc.
4  *
5  * by Tim Bird <tim.bird@am.sony.com>
6  *
7  * See http://opengroup.org/onlinepubs/9699919799/utilities/id.html
8 
9 USE_ID(NEWTOY(id, ">1"USE_ID_SELINUX("Z")"nGgru[!"USE_ID_SELINUX("Z")"Ggu]", TOYFLAG_USR|TOYFLAG_BIN))
10 USE_GROUPS(NEWTOY(groups, NULL, TOYFLAG_USR|TOYFLAG_BIN))
11 USE_LOGNAME(NEWTOY(logname, ">0", TOYFLAG_USR|TOYFLAG_BIN))
12 USE_WHOAMI(OLDTOY(whoami, logname, TOYFLAG_USR|TOYFLAG_BIN))
13 
14 config ID
15   bool "id"
16   default y
17   help
18     usage: id [-nGgru]
19 
20     Print user and group ID.
21 
22     -n	print names instead of numeric IDs (to be used with -Ggu)
23     -G	Show only the group IDs
24     -g	Show only the effective group ID
25     -r	Show real ID instead of effective ID
26     -u	Show only the effective user ID
27 
28 config ID_SELINUX
29   bool
30   default y
31   depends on ID && TOYBOX_SELINUX
32   help
33     usage: id [-Z]
34 
35     -Z Show only SELinux context
36 
37 config GROUPS
38   bool "groups"
39   default y
40   help
41     usage: groups [user]
42 
43     Print the groups a user is in.
44 
45 config LOGNAME
46   bool "logname"
47   default y
48   help
49     usage: logname
50 
51     Print the current user name.
52 
53 config WHOAMI
54   bool "whoami"
55   default y
56   help
57     usage: whoami
58 
59     Print the current user name.
60 */
61 
62 #define FOR_id
63 #include "toys.h"
64 
GLOBALS(int do_u,do_n,do_G,do_Z,is_groups;)65 GLOBALS(
66   int do_u, do_n, do_G, do_Z, is_groups;
67 )
68 
69 static void s_or_u(char *s, unsigned u, int done)
70 {
71   if (TT.do_n) printf("%s", s);
72   else printf("%u", u);
73   if (done) {
74     xputc('\n');
75     exit(0);
76   }
77 }
78 
showid(char * header,unsigned u,char * s)79 static void showid(char *header, unsigned u, char *s)
80 {
81   printf("%s%u(%s)", header, u, s);
82 }
83 
do_id(char * username)84 void do_id(char *username)
85 {
86   int flags, i, ngroups;
87   struct passwd *pw;
88   struct group *grp;
89   uid_t uid = getuid(), euid = geteuid();
90   gid_t gid = getgid(), egid = getegid(), *groups;
91 
92   flags = toys.optflags;
93 
94   // check if a username is given
95   if (username) {
96     pw = xgetpwnam(username);
97     uid = euid = pw->pw_uid;
98     gid = egid = pw->pw_gid;
99     if (TT.is_groups) printf("%s : ", pw->pw_name);
100   }
101 
102   i = flags & FLAG_r;
103   pw = xgetpwuid(i ? uid : euid);
104   if (TT.do_u) s_or_u(pw->pw_name, pw->pw_uid, 1);
105 
106   grp = xgetgrgid(i ? gid : egid);
107   if (flags & FLAG_g) s_or_u(grp->gr_name, grp->gr_gid, 1);
108 
109   if (!TT.do_G && !TT.do_Z) {
110     showid("uid=", pw->pw_uid, pw->pw_name);
111     showid(" gid=", grp->gr_gid, grp->gr_name);
112 
113     if (!i) {
114       if (uid != euid) {
115         pw = xgetpwuid(euid);
116         showid(" euid=", pw->pw_uid, pw->pw_name);
117       }
118       if (gid != egid) {
119         grp = xgetgrgid(egid);
120         showid(" egid=", grp->gr_gid, grp->gr_name);
121       }
122     }
123 
124     showid(" groups=", grp->gr_gid, grp->gr_name);
125   }
126 
127   if (!TT.do_Z) {
128     groups = (gid_t *)toybuf;
129     i = sizeof(toybuf)/sizeof(gid_t);
130     ngroups = username ? getgrouplist(username, gid, groups, &i)
131       : getgroups(i, groups);
132     if (ngroups<0) perror_exit(0);
133 
134     int show_separator = !TT.do_G;
135     for (i = 0; i<ngroups; i++) {
136       if (show_separator) xputc(TT.do_G ? ' ' : ',');
137       show_separator = 1;
138       if (!(grp = getgrgid(groups[i]))) perror_msg(0);
139       else if (TT.do_G) s_or_u(grp->gr_name, grp->gr_gid, 0);
140       else if (grp->gr_gid != egid) showid("", grp->gr_gid, grp->gr_name);
141       else show_separator = 0; // Because we didn't show anything this time.
142     }
143     if (TT.do_G) {
144       xputc('\n');
145       exit(0);
146     }
147   }
148 
149   if (CFG_TOYBOX_SELINUX) {
150     char *context = NULL;
151 
152     if (is_selinux_enabled() < 1) {
153       if (TT.do_Z)
154         error_exit("SELinux disabled");
155     } else if (getcon(&context) == 0) {
156       if (!TT.do_Z) xputc(' ');
157       printf("context=%s", context);
158     }
159     if (CFG_TOYBOX_FREE) free(context);
160   }
161 
162   xputc('\n');
163 }
164 
id_main(void)165 void id_main(void)
166 {
167   // FLAG macros can be 0 if "id" command not enabled, so snapshot them here.
168   if (FLAG_u) TT.do_u |= toys.optflags & FLAG_u;
169   if (FLAG_n) TT.do_n |= toys.optflags & FLAG_n;
170   if (FLAG_G) TT.do_G |= toys.optflags & FLAG_G;
171   if (FLAG_Z) TT.do_Z |= toys.optflags & FLAG_Z;
172 
173   if (toys.optc) while(*toys.optargs) do_id(*toys.optargs++);
174   else do_id(NULL);
175 }
176 
groups_main(void)177 void groups_main(void)
178 {
179   TT.is_groups = 1;
180   TT.do_G = TT.do_n = 1;
181   id_main();
182 }
183 
logname_main(void)184 void logname_main(void)
185 {
186   TT.do_u = TT.do_n = 1;
187   id_main();
188 }
189