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/* ISC license. */
#include <sys/types.h>
#include <pwd.h>
#include <grp.h>
#include <limits.h>
#include <skalibs/uint64.h>
#include <skalibs/gidstuff.h>
#include <skalibs/bytestr.h>
#include <skalibs/sgetopt.h>
#include <skalibs/strerr2.h>
#include <skalibs/env.h>
#include <skalibs/fmtscan.h>
#include <skalibs/djbunix.h>
#define USAGE "s6-envuidgid [ -i | -D defaultuid:defaultgid ] [ -g ] username prog..."
#define dieusage() strerr_dieusage(100, USAGE)
int main (int argc, char const *const *argv, char const *const *envp)
{
uint64 uid ;
gid_t gid ;
gid_t tab[NGROUPS_MAX] ;
int n = 0 ;
int dogroup = 0 ;
int insist = 1 ;
PROG = "s6-envuidgid" ;
{
subgetopt_t l = SUBGETOPT_ZERO ;
for (;;)
{
register int opt = subgetopt_r(argc, argv, "giD:", &l) ;
if (opt == -1) break ;
switch (opt)
{
case 'g' : dogroup = 1 ; break ;
case 'i' : insist = 1 ; break ;
case 'D' :
{
unsigned int pos = uint64_scan(l.arg, &uid) ;
if (!pos)
{
if (l.arg[pos] != ':') dieusage() ;
uid = 0 ;
}
if (!l.arg[pos]) gid = 0 ;
else
{
if (l.arg[pos++] != ':') dieusage() ;
if (!l.arg[pos]) gid = 0 ;
else if (!gid0_scan(l.arg + pos, &gid)) dieusage() ;
}
insist = 0 ;
break ;
}
default : dieusage() ;
}
}
argc -= l.ind ; argv += l.ind ;
}
if (argc < 2) dieusage() ;
if (dogroup)
{
struct group *gr = getgrnam(argv[0]) ;
unsigned int pos = 4 ;
char fmt[4 + GID_FMT] = "GID=" ;
if (gr) gid = gr->gr_gid ;
else if (insist) strerr_dief2x(1, "unknown group: ", argv[0]) ;
pos += gid_fmt(fmt + pos, gid) ;
fmt[pos++] = 0 ;
pathexec_r(argv+1, envp, env_len(envp), fmt, pos) ;
}
else
{
struct passwd *pw = getpwnam(argv[0]) ;
if (pw)
{
uid = pw->pw_uid ;
gid = pw->pw_gid ;
n = prot_readgroups(argv[0], tab, NGROUPS_MAX) ;
if (n < 0)
strerr_diefu2sys(111, "get supplementary groups for ", argv[0]) ;
}
else if (insist) strerr_dief2x(1, "unknown user: ", argv[0]) ;
{
unsigned int pos = 0 ;
char fmt[19 + UINT64_FMT + (n+1) * GID_FMT] ;
byte_copy(fmt + pos, 4, "UID=") ; pos += 4 ;
pos += uint64_fmt(fmt + pos, uid) ;
byte_copy(fmt + pos, 5, "\0GID=") ; pos += 5 ;
pos += gid_fmt(fmt + pos, gid) ;
byte_copy(fmt + pos, 9, "\0GIDLIST=") ; pos += 9 ;
pos += gid_fmtlist(fmt + pos, tab, n) ;
fmt[pos++] = 0 ;
pathexec_r(argv+1, envp, env_len(envp), fmt, pos) ;
}
}
strerr_dieexec(111, argv[1]) ;
}
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