1 /* ISC license. */
2
3 #include <unistd.h>
4 #include <grp.h>
5 #include <limits.h>
6 #include <stdlib.h>
7
8 #include <skalibs/types.h>
9 #include <skalibs/setgroups.h>
10 #include <skalibs/strerr2.h>
11 #include <skalibs/sgetopt.h>
12 #include <skalibs/djbunix.h>
13 #include <skalibs/exec.h>
14
15 #define USAGE "s6-applyuidgid [ -z ] [ -u uid ] [ -g gid ] [ -G gidlist ] [ -U ] prog..."
16 #define dieusage() strerr_dieusage(100, USAGE)
17
main(int argc,char const * const * argv)18 int main (int argc, char const *const *argv)
19 {
20 uid_t uid = 0 ;
21 gid_t gid = 0 ;
22 gid_t gids[NGROUPS_MAX+1] ;
23 size_t gidn = (size_t)-1 ;
24 int unexport = 0 ;
25 PROG = "s6-applyuidgid" ;
26 {
27 subgetopt_t l = SUBGETOPT_ZERO ;
28 for (;;)
29 {
30 int opt = subgetopt_r(argc, argv, "zUu:g:G:", &l) ;
31 if (opt == -1) break ;
32 switch (opt)
33 {
34 case 'z' : unexport = 1 ; break ;
35 case 'u' : if (!uid0_scan(l.arg, &uid)) dieusage() ; break ;
36 case 'g' : if (!gid0_scan(l.arg, &gid)) dieusage() ; break ;
37 case 'G' : if (!gid_scanlist(gids, NGROUPS_MAX, l.arg, &gidn) && *l.arg) dieusage() ; break ;
38 case 'U' :
39 {
40 char const *x = getenv("UID") ;
41 if (!x) strerr_dienotset(100, "UID") ;
42 if (!uid0_scan(x, &uid)) strerr_dieinvalid(100, "UID") ;
43 x = getenv("GID") ;
44 if (!x) strerr_dienotset(100, "GID") ;
45 if (!gid0_scan(x, &gid)) strerr_dieinvalid(100, "GID") ;
46 x = getenv("GIDLIST") ;
47 if (!x) strerr_dienotset(100, "GIDLIST") ;
48 if (!gid_scanlist(gids, NGROUPS_MAX+1, x, &gidn) && *x)
49 strerr_dieinvalid(100, "GIDLIST") ;
50 break ;
51 }
52 default : dieusage() ;
53 }
54 }
55 argc -= l.ind ; argv += l.ind ;
56 }
57 if (!argc) dieusage() ;
58
59 if (gidn != (size_t)-1 && setgroups_and_gid(gid ? gid : getegid(), gidn, gids) < 0)
60 strerr_diefu1sys(111, "set supplementary group list") ;
61 if (gid && setgid(gid) < 0)
62 strerr_diefu1sys(111, "setgid") ;
63 if (uid && setuid(uid) < 0)
64 strerr_diefu1sys(111, "setuid") ;
65
66 if (unexport) xmexec_n(argv, "UID\0GID\0GIDLIST", 16, 3) ;
67 else xexec(argv) ;
68 }
69