diff options
| -rw-r--r-- | toys/pending/su.c | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/toys/pending/su.c b/toys/pending/su.c new file mode 100644 index 00000000..cf9b5997 --- /dev/null +++ b/toys/pending/su.c @@ -0,0 +1,98 @@ +/* su.c - switch user + * + * Copyright 2013 CE Strake <strake888@gmail.com> + * + * See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/su.html + +USE_SU(NEWTOY(su, "lmpc:s:", TOYFLAG_BIN)) + +config SU + bool "su" + default n + help + usage: su [-lmp] [-c cmd] [-s shell] [user [argu...]] + + Switch to given user, or root if not given, and call a shell with the given arguments. + + options: + -s shell to call + -c command to pass to shell with -c + + flags: + -l login shell + -(m|p) preserve environment +*/ + +#define FOR_su +#include "toys.h" + +GLOBALS( + char *sArgu; + char *cArgu; +) + +extern char **environ; + +static void deny () { + printf ("Denied\n"); + xexit (); +} + +void su_main () { + char *name, *passhash, **argu, **argv; + struct passwd *up; + struct spwd *shp; + long ii; + + if (toys.optc && strcmp ("-", toys.optargs[0]) == 0) { + toys.optflags |= FLAG_l; + toys.optc--; toys.optargs++; + } + + if (toys.optc) { + name = toys.optargs[0]; + toys.optc--; toys.optargs++; + } + else name = "root"; + shp = getspnam (name); + if (!shp) perror_exit ("failed to find password"); + + switch (shp -> sp_pwdp[0]) { + case '!': deny (); + case '$': break; + default : error_exit ("bad password format"); + } + + if (read_password (toybuf, sizeof (toybuf), "Password: ") != 0) perror_exit ("failed to read password"); + + passhash = crypt (toybuf, shp -> sp_pwdp); + if (!passhash) perror_exit ("failed to compute password hash"); + for (ii = 0; toybuf[ii]; ii++) toybuf[ii] = 0; + + if (strcmp (passhash, shp -> sp_pwdp) != 0) deny (); + + up = getpwnam (name); + if (!up) perror_exit ("failed to getpwnam"); + + if (setuid (up -> pw_uid) < 0) perror_exit ("failed to setuid"); + if (chdir (up -> pw_dir) < 0) perror_exit ("failed to chdir"); + + argu = xmalloc (sizeof (char *)*(toys.optc + 4)); + argv = argu; + argv[0] = toys.optflags & FLAG_s ? TT.sArgu : up -> pw_shell; + if (toys.optflags & FLAG_c) { + argv[1] = toys.optflags & FLAG_l ? "-lc" : "-c"; + argv[2] = TT.cArgu; + argv += 2; + } + else if (toys.optflags & FLAG_l) (argv++)[1] = "-l"; + for (ii = 0; ii < toys.optc; ii++) argv[ii + 1] = toys.optargs[ii]; + if (execve (argu[0], argu, + toys.optflags & FLAG_l ? (char *[]){ + xmsprintf ( "HOME=%s", up -> pw_dir), + xmsprintf ("SHELL=%s", up -> pw_shell), + xmsprintf ( "USER=%s", up -> pw_name), + xmsprintf ( "TERM=%s", getenv ("TERM")), + 0 + } : environ) < 0) perror_exit ("failed to exec %s", argu[0]); +} |