burrow-pi-img/deps/tools/setuidgids.c
2018-12-03 00:04:18 -08:00

48 lines
1.1 KiB
C

#include <sys/types.h>
#include <pwd.h>
#include <unistd.h>
#include <grp.h>
#include <stdio.h>
#include <stdlib.h>
static int prot_gid(gid_t gid)
{
if (setgroups(1,&gid) == -1) return -1;
return setgid(gid); /* _should_ be redundant, but on some systems it isn't */
}
const char *account;
struct passwd *pw;
int main(int argc, char **argv, char **envp)
{
account = *++argv;
if (!account || !*++argv) {
fprintf(stderr, "setuidgids: usage: setuidgids account child");
exit(EXIT_FAILURE);
}
pw = getpwnam(account);
if (!pw) {
fprintf(stderr, "setuidgids: FATAL: unknown account %s", account);
return EXIT_FAILURE;
}
if (prot_gid(pw->pw_gid) == -1) {
fprintf(stderr, "setuidgids: FATAL: unable to setgid\n");
return EXIT_FAILURE;
}
if (initgroups(pw->pw_name, pw->pw_gid) == -1) {
fprintf(stderr, "setuidgids: FATAL: unable to initgroups\n");
return EXIT_FAILURE;
}
if (setuid(pw->pw_uid) == -1) {
fprintf(stderr, "setuidgids: FATAL: unable to setuid\n");
return EXIT_FAILURE;
}
execvpe(*argv,argv,envp);
fprintf(stderr, "setuidgids: FATAL: unable to run %s\n", *argv);
return EXIT_FAILURE;
}