freebsd-dev/usr.sbin/pw/pw.c
Nate Williams 73375325b1 Fix race condition in pw caused by multiple instances of pwd_mkdb being
run at the same time.

Notes:
    The fileupdate function is still somewhat broken.  Instead of
    returning a failure code if it can't modify the original file it
    renames the .new file and continues as though nothing is wrong.
    This will cause the lock on the original file to be lost and could
    lead to a similar race condition.  I left that portion of the code
    alone since I feel that the maintainer of the code would have a
    better concept of how he wants to handle errors in that function
    than I do.

PR:		bin/6787
Submitted by:	Craig Spannring <cts@internetcds.com>
1998-07-16 17:18:25 +00:00

365 lines
11 KiB
C

/*-
* Copyright (C) 1996
* David L. Nugent. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL DAVID L. NUGENT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static const char rcsid[] =
"$Id: pw.c,v 1.7 1997/10/10 06:23:34 charnier Exp $";
#endif /* not lint */
#include "pw.h"
#include <err.h>
#include <fcntl.h>
#include <paths.h>
#include <sys/wait.h>
const char *Modes[] = {"add", "del", "mod", "show", "next", NULL};
const char *Which[] = {"user", "group", NULL};
static const char *Combo1[] = {
"useradd", "userdel", "usermod", "usershow", "usernext",
"groupadd", "groupdel", "groupmod", "groupshow", "groupnext",
NULL};
static const char *Combo2[] = {
"adduser", "deluser", "moduser", "showuser", "nextuser",
"addgroup", "delgroup", "modgroup", "showgroup", "nextgroup",
NULL};
static struct cargs arglist;
static int getindex(const char *words[], const char *word);
static void cmdhelp(int mode, int which);
static int filelock(const char *filename);
int
main(int argc, char *argv[])
{
int ch;
int mode = -1;
int which = -1;
struct userconf *cnf;
static const char *opts[W_NUM][M_NUM] =
{
{ /* user */
"C:qn:u:c:d:e:p:g:G:mk:s:oL:i:w:h:Db:NPy:Y",
"C:qn:u:rY",
"C:qn:u:c:d:e:p:g:G:ml:k:s:w:L:h:FNPY",
"C:qn:u:FPa",
"C:q"
},
{ /* grp */
"C:qn:g:h:M:pNPY",
"C:qn:g:Y",
"C:qn:g:l:h:FM:m:NPY",
"C:qn:g:FPa",
"C:q"
}
};
static int (*funcs[W_NUM]) (struct userconf * _cnf, int _mode, struct cargs * _args) =
{ /* Request handlers */
pw_user,
pw_group
};
umask(0); /* We wish to handle this manually */
LIST_INIT(&arglist);
/*
* Break off the first couple of words to determine what exactly
* we're being asked to do
*/
while (argc > 1 && *argv[1] != '-') {
int tmp;
if ((tmp = getindex(Modes, argv[1])) != -1)
mode = tmp;
else if ((tmp = getindex(Which, argv[1])) != -1)
which = tmp;
else if ((tmp = getindex(Combo1, argv[1])) != -1 || (tmp = getindex(Combo2, argv[1])) != -1) {
which = tmp / M_NUM;
mode = tmp % M_NUM;
} else if (strcmp(argv[1], "help") == 0)
cmdhelp(mode, which);
else if (which != -1 && mode != -1 && arglist.lh_first == NULL)
addarg(&arglist, 'n', argv[1]);
else
errx(EX_USAGE, "unknown keyword `%s'", argv[1]);
++argv;
--argc;
}
/*
* Bail out unless the user is specific!
*/
if (mode == -1 || which == -1)
cmdhelp(mode, which);
/*
* We know which mode we're in and what we're about to do, so now
* let's dispatch the remaining command line args in a genric way.
*/
optarg = NULL;
while ((ch = getopt(argc, argv, opts[which][mode])) != -1) {
if (ch == '?')
errx(EX_USAGE, NULL);
else
addarg(&arglist, ch, optarg);
optarg = NULL;
}
/*
* Must be root to attempt an update
*/
if (geteuid() != 0 && mode != M_PRINT && mode != M_NEXT && getarg(&arglist, 'N')==NULL)
errx(EX_NOPERM, "you must be root to run this program");
/*
* We should immediately look for the -q 'quiet' switch so that we
* don't bother with extraneous errors
*/
if (getarg(&arglist, 'q') != NULL)
freopen("/dev/null", "w", stderr);
/*
* Now, let's do the common initialisation
*/
cnf = read_userconfig(getarg(&arglist, 'C') ? getarg(&arglist, 'C')->val : NULL);
/*
* Be pessimistic and lock the master passowrd and group
* files right away. Keep it locked for the duration.
*/
if (-1 == filelock(_PATH_GROUP) || -1 == filelock(_PATH_MASTERPASSWD))
{
ch = EX_IOERR;
}
else
{
ch = funcs[which] (cnf, mode, &arglist);
}
/*
* If everything went ok, and we've been asked to update
* the NIS maps, then do it now
*/
if (ch == EXIT_SUCCESS && getarg(&arglist, 'Y') != NULL) {
pid_t pid;
fflush(NULL);
if (chdir(_PATH_YP) == -1)
warn("chdir(" _PATH_YP ")");
else if ((pid = fork()) == -1)
warn("fork()");
else if (pid == 0) {
/* Is make anywhere else? */
execlp("/usr/bin/make", "make", NULL);
_exit(1);
} else {
int i;
waitpid(pid, &i, 0);
if ((i = WEXITSTATUS(i)) != 0)
errx(ch, "make exited with status %d", i);
else
pw_log(cnf, mode, which, "NIS maps updated");
}
}
return ch;
}
static int
filelock(const char *filename)
{
return open(filename, O_RDONLY | O_EXLOCK, 0);
}
static int
getindex(const char *words[], const char *word)
{
int i = 0;
while (words[i]) {
if (strcmp(words[i], word) == 0)
return i;
i++;
}
return -1;
}
/*
* This is probably an overkill for a cmdline help system, but it reflects
* the complexity of the command line.
*/
static void
cmdhelp(int mode, int which)
{
if (which == -1)
fprintf(stderr, "usage: pw [user|group] [add|del|mod|show|next] [ help | switches/values ]\n");
else if (mode == -1)
fprintf(stderr, "usage: pw %s [add|del|mod|show|next] [ help | switches/values ]\n", Which[which]);
else {
/*
* We need to give mode specific help
*/
static const char *help[W_NUM][M_NUM] =
{
{
"usage: pw useradd [name] [switches]\n"
"\t-C config configuration file\n"
"\t-q quiet operation\n"
" Adding users:\n"
"\t-n name login name\n"
"\t-u uid user id\n"
"\t-c comment user name/comment\n"
"\t-d directory home directory\n"
"\t-e date account expiry date\n"
"\t-p date password expiry date\n"
"\t-g grp initial group\n"
"\t-G grp1,grp2 additional groups\n"
"\t-m [ -k dir ] create and set up home\n"
"\t-s shell name of login shell\n"
"\t-o duplicate uid ok\n"
"\t-L class user class\n"
"\t-h fd read password on fd\n"
"\t-Y update NIS maps\n"
"\t-N no update\n"
" Setting defaults:\n"
"\t-D set user defaults\n"
"\t-b dir default home root dir\n"
"\t-e period default expiry period\n"
"\t-p period default password change period\n"
"\t-g group default group\n"
"\t-G grp1,grp2 additional groups\n"
"\t-L class default user class\n"
"\t-k dir default home skeleton\n"
"\t-u min,max set min,max uids\n"
"\t-i min,max set min,max gids\n"
"\t-w method set default password method\n"
"\t-s shell default shell\n"
"\t-y path set NIS passwd file path\n",
"usage: pw userdel [uid|name] [switches]\n"
"\t-n name login name\n"
"\t-u uid user id\n"
"\t-Y update NIS maps\n"
"\t-r remove home & contents\n",
"usage: pw usermod [uid|name] [switches]\n"
"\t-C config configuration file\n"
"\t-q quiet operation\n"
"\t-F force add if no user\n"
"\t-n name login name\n"
"\t-u uid user id\n"
"\t-c comment user name/comment\n"
"\t-d directory home directory\n"
"\t-e date account expiry date\n"
"\t-p date password expiry date\n"
"\t-g grp initial group\n"
"\t-G grp1,grp2 additional groups\n"
"\t-l name new login name\n"
"\t-L class user class\n"
"\t-m [ -k dir ] create and set up home\n"
"\t-s shell name of login shell\n"
"\t-w method set new password using method\n"
"\t-h fd read password on fd\n"
"\t-Y update NIS maps\n"
"\t-N no update\n",
"usage: pw usershow [uid|name] [switches]\n"
"\t-n name login name\n"
"\t-u uid user id\n"
"\t-F force print\n"
"\t-P prettier format\n"
"\t-a print all users\n",
"usage: pw usernext [switches]\n"
"\t-C config configuration file\n"
},
{
"usage: pw groupadd [group|gid] [switches]\n"
"\t-C config configuration file\n"
"\t-q quiet operation\n"
"\t-n group group name\n"
"\t-g gid group id\n"
"\t-M usr1,usr2 add users as group members\n"
"\t-o duplicate gid ok\n"
"\t-Y update NIS maps\n"
"\t-N no update\n",
"usage: pw groupdel [group|gid] [switches]\n"
"\t-n name group name\n"
"\t-g gid group id\n"
"\t-Y update NIS maps\n",
"usage: pw groupmod [group|gid] [switches]\n"
"\t-C config configuration file\n"
"\t-q quiet operation\n"
"\t-F force add if not exists\n"
"\t-n name group name\n"
"\t-g gid group id\n"
"\t-M usr1,usr2 replaces users as group members\n"
"\t-m usr1,usr2 add users as group members\n"
"\t-l name new group name\n"
"\t-Y update NIS maps\n"
"\t-N no update\n",
"usage: pw groupshow [group|gid] [switches]\n"
"\t-n name group name\n"
"\t-g gid group id\n"
"\t-F force print\n"
"\t-P prettier format\n"
"\t-a print all accounting groups\n",
"usage: pw groupnext [switches]\n"
"\t-C config configuration file\n"
}
};
fprintf(stderr, help[which][mode]);
}
exit(EXIT_FAILURE);
}
struct carg *
getarg(struct cargs * _args, int ch)
{
struct carg *c = _args->lh_first;
while (c != NULL && c->ch != ch)
c = c->list.le_next;
return c;
}
struct carg *
addarg(struct cargs * _args, int ch, char *argstr)
{
struct carg *ca = malloc(sizeof(struct carg));
if (ca == NULL)
errx(EX_OSERR, "out of memory");
ca->ch = ch;
ca->val = argstr;
LIST_INSERT_HEAD(_args, ca, list);
return ca;
}