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/* Hurdish login
Copyright (C) 1995 Free Software Foundation, Inc.
Written by Miles Bader <miles@gnu.ai.mit.edu>
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation; either version 2, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <hurd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>
#include <ctype.h>
#include <utmp.h>
#include <pwd.h>
#include <grp.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/fcntl.h>
#include <argp.h>
#include <argz.h>
#include <envz.h>
#include <idvec.h>
#include <error.h>
#include <hurd/lookup.h>
extern error_t
exec_reauth (auth_t auth, int secure, int must_reauth,
mach_port_t *ports, unsigned num_ports,
mach_port_t *fds, unsigned num_fds);
extern error_t
hurd_file_name_path_lookup (error_t (*use_init_port)
(int which,
error_t (*operate) (mach_port_t)),
file_t (*get_dtable_port) (int fd),
const char *file_name, const char *path,
int flags, mode_t mode,
file_t *result);
#define DEFAULT_NOBODY "login"
#define _PATH_MOTD "/etc/motd" /* XXX */
/* Defaults for various login parameters. */
char *default_args[] = {
"SHELL=" _PATH_BSHELL,
"BACKUP_SHELL=" _PATH_BSHELL, /* shell to use if we can't exec SHELL. */
"HOME=/etc/login",
"USER=login",
"UMASK=0",
"NAME=Not logged in",
"HUSHLOGIN=.hushlogin", /* Looked up relative new home dir. */
"MOTD=" _PATH_MOTD,
"PATH=" _PATH_DEFPATH,
0
};
/* Default values for the new environment. */
char *default_env[] = {
"PATH=" _PATH_DEFPATH,
0
};
/* Which things are copied from the login parameters into the environment. */
char *copied_args[] = { "SHELL", "HOME", "NAME", "VIA", "VIA_ADDR", "PATH", 0 };
static struct argp_option options[] =
{
{"arg0", '0', "ARG", 0, "Make ARG the shell's argv[0]"},
{"environ", 'e', "ENTRY", 0, "Add ENTRY to the environment"},
{"environ-default", 'E', "ENTRY", 0, "Use ENTRY as a default environment variable"},
{"no-args", 'x', 0, 0, "Don't login args into the environment"},
{"arg", 'a', "ARG", 0, "Add login parameter ARG"},
{"arg-default", 'A', "ARG", 0, "Use ARG as a default login parameter"},
{"no-environ", 'X', 0, 0, "Don't add the parent environment as default login params"},
{"user", 'u', "USER", 0, "Add USER to the effective uids"},
{"avail-user",'U', "USER", 0, "Add USER to the available uids"},
{"group", 'g', "GROUP", 0, "Add GROUP to the effective groups"},
{"avail-group",'G',"GROUP", 0, "Add GROUP to the available groups"},
{"no-login", 'L', 0, 0, "Don't modify the shells argv[0] to look"
" like a login shell"},
{"nobody", 'n', "USER", 0, "Use USER's passwd entry to fetch the default"
" login params if there are no uids (default `" DEFAULT_NOBODY "')"},
{"inherit-environ", 'p', 0, 0, "Inherit the parent's environment"},
{"via", 'h', "HOST", 0, "This login is from HOST"},
{"no-passwd", 'f', 0, 0, "Don't ask for passwords"},
{"no-utmp", 'z', 0, 0, "Don't put an entry in utmp"},
{"paranoid", 'P', 0, 0, "Don't admit that a user doesn't exist"},
{"keep", 'k', 0, 0, "Keep the old available ids, and save the old"
"effective ids as available ids"},
{"shell-arg", 'S', 0, 0, "Use the first shell arg as the shell to invoke"},
{"retry", 'R', "SHELL", OPTION_ARG_OPTIONAL,
"Re-exec SHELL (default login) with no users after non-fatal errors"},
{0, 0}
};
static char *args_doc = "[USER [ARG...]]";
static char *doc =
"To give args to the shell without specifying a user, use - for USER.\n"
"Current login parameters include HOME, SHELL, USER, NAME, and ROOT.";
/* Outputs whatever can be read from the io_t NODE to standard output, and
then close it. If NODE is MACH_PORT_NULL, assumes an error happened, and
prints an error message using ERRNO and STR. */
static void
cat (mach_port_t node, char *str)
{
error_t err;
if (node == MACH_PORT_NULL)
err = errno;
else
for (;;)
{
char buf[1024], *data = buf;
mach_msg_type_number_t data_len = sizeof (buf);
err = io_read (node, &data, &data_len, -1, 16384);
if (err || data_len == 0)
break;
else
{
write (0, data, data_len);
if (data != buf)
vm_deallocate (mach_task_self (), (vm_address_t)data, data_len);
}
}
if (err)
error (0, errno, "%s", str);
}
/* Returns the host from the umtp entry for the current tty, or 0. The
return value is in a static buffer. */
static char *
get_utmp_host ()
{
static struct utmp utmp;
int tty = ttyslot ();
char *host = 0;
if (tty > 0)
{
int fd = open (_PATH_UTMP, O_RDONLY);
if (fd >= 0)
{
lseek (fd, (off_t)(tty * sizeof (struct utmp)), L_SET);
if (read (fd, &utmp, sizeof utmp) == sizeof utmp
&& *utmp.ut_name && *utmp.ut_line && *utmp.ut_host)
host = utmp.ut_host;
close (fd);
}
}
return host;
}
/* Add a utmp entry based on the parameters in ARGS & ARGS_LEN, from tty
TTY_FD. If INHERIT_HOST is true, the host parameters in ARGS aren't to be
trusted, so try to get the host from the existing utmp entry (this only
works if re-logging in during an existing session). */
static void
add_utmp_entry (char *args, unsigned args_len, int tty_fd, int inherit_host)
{
extern void login (struct utmp *); /* in libutil */
struct utmp utmp;
char bogus_tty[sizeof (_PATH_TTY) + 2];
char *tty = ttyname (0), *host;
if (! tty)
{
sprintf (bogus_tty, "%s??", _PATH_TTY);
tty = bogus_tty;
}
if (strncmp (tty, _PATH_DEV, sizeof (_PATH_DEV) - 1) == 0)
/* Remove a prefix of `/dev/'. */
tty += sizeof (_PATH_DEV) - 1;
bzero (&utmp, sizeof (utmp));
time (&utmp.ut_time);
strncpy (utmp.ut_name, envz_get (args, args_len, "USER") ?: "",
sizeof (utmp.ut_name));
strncpy (utmp.ut_line, tty, sizeof (utmp.ut_line));
if (inherit_host)
host = get_utmp_host ();
else
{
host = envz_get (args, args_len, "VIA");
if (host && strlen (host) > sizeof (utmp.ut_host))
host = envz_get (args, args_len, "VIA_ADDR") ?: host;
}
strncpy (utmp.ut_host, host ?: "", sizeof (utmp.ut_host));
login (&utmp);
}
/* Lookup the host HOST, and add entries for VIA (the host name), and
VIA_ADDR (the dotted decimal address) to ARGS & ARGS_LEN. */
static error_t
add_canonical_host (char **args, unsigned *args_len, char *host)
{
struct hostent *he = gethostbyname (host);
if (he)
{
char *addr = 0;
/* Try and get an ascii version of the numeric host address. */
switch (he->h_addrtype)
{
case AF_INET:
addr = strdup (inet_ntoa (*(struct in_addr *)he->h_addr));
break;
}
if (addr && strcmp (he->h_name, addr) == 0)
/* gethostbyname() cheated! Lookup the host name via the address
this time to get the actual host name. */
he = gethostbyaddr (he->h_addr, he->h_length, he->h_addrtype);
if (he)
host = he->h_name;
if (addr)
{
envz_add (args, args_len, "VIA_ADDR", addr);
free (addr);
}
}
return envz_add (args, args_len, "VIA", host);
}
/* Add the `=' separated environment entry ENTRY to ENV & ENV_LEN, exiting
with an error message if we can't. */
static void
add_entry (char **env, unsigned *env_len, char *entry)
{
char *name = strsep (&entry, "=");
error_t err = envz_add (env, env_len, name, entry);
if (err)
error (8, err, "Adding %s", entry);
}
void
main(int argc, char *argv[])
{
int i;
io_t node;
char *arg, *path;
error_t err = 0;
char *nobody = DEFAULT_NOBODY; /* Where to get params if there is no user. */
char *args = 0; /* The login parameters */
unsigned args_len = 0;
char *passwd = 0; /* Login parameters from /etc/passwd */
unsigned passwd_len = 0;
char *args_defs = 0; /* Defaults for login parameters. */
unsigned args_defs_len = 0;
char *env = 0; /* The new environment. */
unsigned env_len = 0;
char *env_defs = 0; /* Defaults for the environment. */
unsigned env_defs_len = 0;
char *parent_env = 0; /* The environment we got from our parent */
unsigned parent_env_len = 0;
int no_environ = 0; /* If false, use the env as default params. */
int no_args = 0; /* If false, put login params in the env. */
int inherit_environ = 0; /* True if we shouldn't clear our env. */
int saw_user_arg = 0; /* True if we've seen the USER argument. */
int no_passwd = 0; /* Don't bother verifying what we're doing. */
int no_utmp = 0; /* Don't put an entry in utmp. */
int no_login = 0; /* Don't prepend `-' to the shells argv[0]. */
int retry = 0; /* For some failures, exec a login shell. */
int paranoid = 0; /* Admit no knowledge. */
int shell_arg = 0; /* If there are shell args, use the first as
the shell name. */
char *retry_shell = 0; /* Optionally use this shell for retries. */
struct idvec *eff_uids = make_idvec (); /* The UIDs of the new shell. */
struct idvec *eff_gids = make_idvec (); /* The EFF_GIDs. */
struct idvec *avail_uids = make_idvec (); /* The aux UIDs of the new shell. */
struct idvec *avail_gids = make_idvec (); /* The aux EFF_GIDs. */
struct idvec *parent_uids = make_idvec (); /* Parent uids, -SETUID. */
struct idvec *parent_gids = make_idvec (); /* Parent gids, -SETGID. */
char *shell = 0; /* The shell program to run. */
char *sh_arg0 = 0; /* The shell's argv[0]. */
char *sh_args = 0; /* The args to the shell. */
unsigned sh_args_len = 0;
mach_port_t exec; /* The shell executable. */
mach_port_t cwd; /* The child's CWD. */
mach_port_t root; /* The child's root directory. */
mach_port_t ports[INIT_PORT_MAX]; /* Init ports for the new process. */
int ints[INIT_INT_MAX]; /* Init ints for it. */
mach_port_t fds[3]; /* File descriptors passed. */
mach_port_t auth; /* The new shell's authentication. */
mach_port_t proc_server = getproc ();
mach_port_t parent_auth = getauth ();
/* These three functions are to do child-authenticated lookups. See
<hurd/lookup.h> for an explanation. */
error_t use_child_init_port (int which, error_t (*operate)(mach_port_t))
{
return (*operate)(ports[which]);
}
mach_port_t get_child_fd_port (int fd)
{
return fd < 0 || fd > 2 ? __hurd_fail (EBADF) : fds[fd];
}
mach_port_t child_lookup (char *name, char *path, int flags)
{
mach_port_t port = MACH_PORT_NULL;
errno =
hurd_file_name_path_lookup (use_child_init_port, get_child_fd_port,
name, path, flags, 0, &port);
return port;
}
/* Print an error message with FMT, STR and ERR. Then, if RETRY is on,
exec a default login shell, otherwise exit with CODE (must be non-0). */
void fail (int code, error_t err, char *fmt, const char *str)
{
/* Two 0's at end, so we can fill in the first with the shell arg. */
char *retry_argv[] =
{argv[0], "-aMOTD", "-aHOME", "-e_LOGIN_RETRY=yes", "-p", 0, 0};
int retry_argc = (sizeof retry_argv / sizeof retry_argv[0]) - 1;
error (retry ? 0 : code, err, fmt, str); /* May exit... */
if (retry_shell)
asprintf (&retry_argv[retry_argc++ - 1], "-aSHELL=%s", retry_shell);
/* Reinvoke ourselves with no userids or anything; shouldn't return. */
_argp_unlock_xxx (); /* Hack to get around problems with getopt. */
main (retry_argc, retry_argv);
exit (code); /* But if it does... */
}
/* Make sure that the parent_[ug]ids are filled in. To make them useful
for su'ing, each is the avail ids with all effective ids but the first
appended; this gets rid of the effect of login being suid, and is useful
as the new process's avail id list (e.g., the real id is right). */
void need_parent_ids ()
{
if (parent_uids->num == 0 && parent_gids->num == 0)
{
struct idvec *p_eff_uids = make_idvec ();
struct idvec *p_eff_gids = make_idvec ();
if (!p_eff_uids || !p_eff_gids)
err = ENOMEM;
if (! err)
err = idvec_merge_auth (p_eff_uids, parent_uids,
p_eff_gids, parent_gids,
parent_auth);
if (! err)
{
idvec_delete (p_eff_uids, 0); /* Counteract setuid. */
idvec_delete (p_eff_gids, 0);
err = idvec_merge (parent_uids, p_eff_uids);
if (! err)
err = idvec_merge (parent_gids, p_eff_gids);
}
if (err)
error (39, err, "Can't get uids");
}
}
/* Returns true if the *caller* of this login program has UID. */
int parent_has_uid (uid_t uid)
{
need_parent_ids ();
return idvec_contains (parent_uids, uid);
}
/* Returns true if the *caller* of this login program has GID. */
int parent_has_gid (gid_t gid)
{
need_parent_ids ();
return idvec_contains (parent_gids, gid);
}
/* Make sure the user should be allowed to do this. */
void verify_passwd (const char *name, const char *password,
uid_t id, int is_group)
{
extern char *crypt (const char salt[2], const char *string);
char *prompt, *unencrypted, *encrypted;
if (!password || !*password
|| idvec_contains (is_group ? eff_gids : eff_uids, id)
|| idvec_contains (is_group ? avail_gids : avail_uids, id)
|| (no_passwd
&& (parent_has_uid (0)
|| is_group ? parent_has_uid (id) : parent_has_gid (id))))
return; /* Already got this one. */
if (name)
asprintf (&prompt, "Password for %s%s:",
is_group ? "group " : "", name);
else
prompt = "Password:";
unencrypted = getpass (prompt);
encrypted = crypt (unencrypted, password);
/* Paranoia may destroya. */
memset (unencrypted, 0, strlen (unencrypted));
if (name)
free (prompt);
if (strcmp (encrypted, password) != 0)
fail (50, 0, "Incorrect password", 0);
}
/* Parse our options... */
error_t parse_opt (int key, char *arg, struct argp_state *state)
{
switch (key)
{
case 'n': nobody = arg; break;
case 'p': inherit_environ = 1; break;
case 'x': no_args = 1; break;
case 'X': no_environ = 1; break;
case 'e': add_entry (&env, &env_len, arg); break;
case 'E': add_entry (&env_defs, &env_defs_len, arg); break;
case 'a': add_entry (&args, &args_len, arg); break;
case 'A': add_entry (&args_defs, &args_defs_len, arg); break;
case '0': sh_arg0 = arg; break;
case 'h': add_canonical_host (&args, &args_len, arg); break;
case 'z': no_utmp = 1; break;
case 'L': no_login = 1; break;
case 'f': no_passwd = 1; break;
case 'R': retry = 1; retry_shell = arg; break;
case 'P': paranoid = 1; break;
case 'S': shell_arg = 1; break;
case 'k':
need_parent_ids ();
idvec_merge (avail_uids, parent_uids);
idvec_merge (avail_gids, parent_gids);
break;
case ARGP_KEY_ARG:
if (saw_user_arg)
{
err = argz_add (&sh_args, &sh_args_len, arg);
if (err)
error (9, err, "Adding %s", arg);
break;
}
saw_user_arg = 1;
if (strcmp (arg, "-") == 0)
arg = 0; /* Just like there weren't any args at all. */
/* Fall through to deal with adding the user. */
case 'u':
case 'U':
case ARGP_KEY_NO_ARGS:
{
/* USER is whom to look up. If it's 0, then we hit the end of
the sh_args without seeing a user, so we want to add defaults
values for `nobody'. */
char *user = arg ?: nobody;
struct passwd *pw =
isdigit (*user) ? getpwuid (atoi (user)) : getpwnam (user);
/* True if this is the user arg and there were no user options. */
int only_user =
(key == ARGP_KEY_ARG
&& eff_uids->num == 0 && avail_uids->num <= parent_uids->num
&& eff_gids->num == 0 && avail_gids->num <= parent_gids->num);
if (! pw)
if (! arg)
/* It was nobody anyway. Just use the defaults. */
break;
else if (paranoid)
/* In paranoid mode, we don't admit we don't know about a
user, so we just ask for a password we we know the user
can't supply. */
verify_passwd (only_user ? 0 : user, "*", -1, 0);
else
fail (10, 0, "%s: Unknown user", user);
if (arg)
/* If it's not nobody, make sure we're authorized. */
verify_passwd (only_user ? 0 : pw->pw_name, pw->pw_passwd,
pw->pw_uid, 0);
if (key == 'U')
/* Add available ids instead of effective ones. */
{
idvec_add_new (avail_uids, pw->pw_uid);
idvec_add_new (avail_gids, pw->pw_gid);
}
else
{
if (key == ARGP_KEY_ARG || eff_uids->num == 0)
/* If it's the argument (as opposed to option) specifying a
user, or the first option user, then we get defaults for
various things from the password entry. */
{
envz_add (&passwd, &passwd_len, "HOME", pw->pw_dir);
envz_add (&passwd, &passwd_len, "SHELL", pw->pw_shell);
envz_add (&passwd, &passwd_len, "NAME", pw->pw_gecos);
envz_add (&passwd, &passwd_len, "USER", pw->pw_name);
}
if (arg) /* A real user. */
if (key == ARGP_KEY_ARG)
/* The main user arg, make sure it goes at the
beginning. */
{
idvec_insert_only (eff_uids, 0, pw->pw_uid);
idvec_insert_only (eff_gids, 0, pw->pw_gid);
}
else
{
idvec_add_new (eff_uids, pw->pw_uid);
idvec_add_new (eff_gids, pw->pw_gid);
}
}
}
break;
case 'g':
case 'G':
{
struct group *gr =
isdigit (*arg) ? getgrgid (atoi (arg)) : getgrnam (arg);
if (! gr)
fail (11, 0, "%s: Unknown group", arg);
verify_passwd (gr->gr_name, gr->gr_passwd, gr->gr_gid, 1);
idvec_add_new (key == 'g' ? eff_gids : avail_gids, gr->gr_gid);
}
break;
default: return EINVAL;
}
return 0;
}
struct argp argp = {options, parse_opt, args_doc, doc};
/* Don't allow logins if the nologin file exists. */
node = file_name_lookup (_PATH_NOLOGIN, O_RDONLY, 0);
if (node != MACH_PORT_NULL)
{
cat (node, _PATH_NOLOGIN);
exit (40);
}
/* Put in certain last-ditch defaults. */
err = argz_create (default_args, &args_defs, &args_defs_len);
if (! err)
err = argz_create (default_env, &env_defs, &env_defs_len);
if (err)
error (23, err, "adding defaults");
err = argz_create (environ, &parent_env, &parent_env_len);
/* Parse our options. */
argp_parse (&argp, argc, argv, 0, 0);
/* Now that we've parsed the command line, put together all these
environments we've gotten from various places. There are two targets:
(1) the login parameters, and (2) the child environment.
The login parameters come from these sources (in priority order):
a) User specified (with the --arg option)
b) From the passwd file entry for the user being logged in as
c) From the parent environment, if --no-environ wasn't specified
d) From the user-specified defaults (--arg-default)
e) From last-ditch defaults given by the DEFAULT_* defines above
The child environment is from:
a) User specified (--environ)
b) From the login parameters (if --no-args wasn't specified)
c) From the parent environment, if --inherit-environ was specified
d) From the user-specified default env values (--environ-default)
e) From last-ditch defaults given by the DEFAULT_* defines above
*/
/* Merge the login parameters. */
err = envz_merge (&args, &args_len, passwd, passwd_len, 0);
if (! err && ! no_environ)
err = envz_merge (&args, &args_len, parent_env, parent_env_len, 0);
if (! err)
err = envz_merge (&args, &args_len, args_defs, args_defs_len, 0);
if (err)
error (24, err, "merging parameters");
/* Make sure the new process has a real uid/gid (we add the ids twice, for
posix compatibility, once for the real id, and again for the saved). */
if (avail_uids->num == 0 && eff_uids->num > 0)
{
idvec_add (avail_uids, eff_uids->ids[0]);
idvec_add (avail_uids, eff_uids->ids[0]);
}
if (avail_gids->num == 0 && eff_gids->num > 0)
{
idvec_add (avail_gids, eff_gids->ids[0]);
idvec_add (avail_gids, eff_gids->ids[0]);
}
err =
auth_makeauth (getauth (), 0, MACH_MSG_TYPE_COPY_SEND, 0,
eff_uids->ids, eff_uids->num,
avail_uids->ids, avail_uids->num,
eff_gids->ids, eff_gids->num,
avail_gids->ids, avail_gids->num,
&auth);
if (err)
fail (3, err, "Authentication failure", 0);
proc_make_login_coll (proc_server);
if (eff_uids->num > 0)
proc_setowner (proc_server, eff_uids->ids[0]);
/* XXX else clear the owner, once there's a proc call to do it. */
/* Now start constructing the exec arguments. */
bzero (ints, sizeof (*ints) * INIT_INT_MAX);
arg = envz_get (args, args_len, "UMASK");
ints[INIT_UMASK] = arg && *arg ? strtoul (arg, 0, 8) : umask (0);
for (i = 0; i < 3; i++)
fds[i] = getdport (i);
for (i = 0; i < INIT_PORT_MAX; i++)
ports[i] = MACH_PORT_NULL;
ports[INIT_PORT_PROC] = getproc ();
ports[INIT_PORT_CRDIR] = getcrdir (); /* May be replaced below. */
ports[INIT_PORT_CWDIR] = getcwdir (); /* " */
/* Now reauthenticate all of the ports we're passing to the child. */
err = exec_reauth (auth, 0, 1, ports, INIT_PORT_MAX, fds, 3);
if (err)
error (40, err, "Port reauth failure");
/* These are the default values for the child's root/cwd. We don't want to
modify PORTS just yet, because we use it to do child-authenticated
lookups. */
root = ports[INIT_PORT_CRDIR];
cwd = ports[INIT_PORT_CWDIR];
/* Find the shell executable (we copy the name, as ARGS may be changed). */
if (shell_arg && sh_args && *sh_args)
/* Special case for su mode: get the shell from the args if poss. */
{
shell = strdup (sh_args);
argz_delete (&sh_args, &sh_args_len, sh_args); /* Get rid of it. */
}
else
{
arg = envz_get (args, args_len, "SHELL");
if (arg && *arg)
shell = strdup (arg);
else
shell = 0;
}
path = envz_get (args, args_len, "PATH");
exec = shell ? child_lookup (shell, path, O_EXEC) : MACH_PORT_NULL;
if (exec == MACH_PORT_NULL)
{
char *backup = envz_get (args, args_len, "BACKUP_SHELL");
err = errno; /* Save original lookup errno. */
if (backup && *backup && (!shell || strcmp (shell, backup) != 0))
exec = child_lookup (backup, path, O_EXEC);
/* Give the error message, but only exit if we couldn't default. */
if (exec == MACH_PORT_NULL)
fail (1, err, "%s", shell);
else
error (0, err, "%s", shell);
/* If we get here, we looked up the default shell ok. */
shell = strdup (backup);
error (0, 0, "Using SHELL=%s", shell);
envz_add (&args, &args_len, "SHELL", shell);
err = 0; /* Don't emit random err msgs later! */
}
/* Now maybe change the cwd/root in the child. */
arg = envz_get (args, args_len, "HOME");
if (arg && *arg)
{
cwd = child_lookup (arg, 0, O_RDONLY);
if (cwd == MACH_PORT_NULL)
{
error (0, errno, "%s", arg);
error (0, 0, "Using HOME=/");
envz_add (&args, &args_len, "HOME", "/");
}
}
arg = envz_get (args, args_len, "ROOT");
if (arg && *arg)
{
root = child_lookup (arg, 0, O_RDONLY);
if (root == MACH_PORT_NULL)
fail (40, errno, "%s", arg);
}
/* Build the child environment. */
if (! no_args)
/* We can't just merge ARGS, because it may contain the parent
environment, which we don't always want in the child environment, so
we pick out only those values of args which actually *are* args. */
{
char **name;
for (name = copied_args; *name && !err; name++)
if (! envz_get (env, env_len, *name))
{
char *val = envz_get (args, args_len, *name);
if (val && *val)
err = envz_add (&env, &env_len, *name, val);
}
if (!err && !envz_entry (args, args_len, "LOGNAME"))
/* Copy the user arg into the environment as LOGNAME. */
{
char *user = envz_get (args, args_len, "USER");
if (user)
err = envz_add (&env, &env_len, "LOGNAME", user);
}
}
if (! err && inherit_environ)
err = envz_merge (&env, &env_len, parent_env, parent_env_len, 0);
if (! err)
err = envz_merge (&env, &env_len, env_defs, env_defs_len, 0);
if (err)
error (24, err, "Can't build environment");
if (! sh_arg0)
/* The shells argv[0] defaults to the basename of the shell. */
{
char *shell_base = rindex (shell, '/');
if (shell_base)
shell_base++;
else
shell_base = shell;
if (no_login)
sh_arg0 = shell_base;
else
{
sh_arg0 = malloc (strlen (shell_base) + 2);
if (! sh_arg0)
err = ENOMEM;
else
/* Prepend the name with a `-', as is the odd custom. */
{
sh_arg0[0] = '-';
strcpy (sh_arg0 + 1, shell_base);
}
}
}
if (! err)
err = argz_insert (&sh_args, &sh_args_len, sh_args, sh_arg0);
if (err)
error (21, err, "Error building shell args");
/* Maybe output the message of the day. Note that we we the child's
authentication to do it, so that this program can't be used to read
arbitrary files! */
arg = envz_get (args, args_len, "MOTD");
if (arg && *arg)
{
char *hush = envz_get (args, args_len, "HUSHLOGIN");
mach_port_t hush_node =
(hush && *hush) ? child_lookup (hush, 0, O_RDONLY) : MACH_PORT_NULL;
if (hush_node == MACH_PORT_NULL)
{
mach_port_t motd_node = child_lookup (arg, 0, O_RDONLY);
if (motd_node != MACH_PORT_NULL)
cat (motd_node, arg);
}
else
mach_port_deallocate (mach_task_self (), hush_node);
}
/* Now that we don't need to use PORTS for lookups anymore, put the correct
ROOT and CWD in. */
ports[INIT_PORT_CRDIR] = root;
ports[INIT_PORT_CWDIR] = cwd;
/* Get rid of any accumulated null entries in env. */
envz_strip (&env, &env_len);
/* No more authentications to fail, so cross our fingers and add our utmp
entry. */
if (! no_utmp)
add_utmp_entry (args, args_len, 0, !parent_has_uid (0));
err = file_exec (exec, mach_task_self (),
EXEC_NEWTASK | EXEC_DEFAULTS | EXEC_SECURE,
sh_args, sh_args_len, env, env_len,
fds, MACH_MSG_TYPE_COPY_SEND, 3,
ports, MACH_MSG_TYPE_COPY_SEND, INIT_PORT_MAX,
ints, INIT_INT_MAX,
0, 0, 0, 0);
if (err)
error(5, err, "%s", shell);
exit(0);
}
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