OpenBSD-4.6/lib/libutil/passwd.c
/* $OpenBSD: passwd.c,v 1.49 2006/12/20 23:07:36 ray Exp $ */
/*
* Copyright (c) 1987, 1993, 1994, 1995
* The Regents of the University of California. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 THE REGENTS 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.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <pwd.h>
#include <err.h>
#include <errno.h>
#include <paths.h>
#include <signal.h>
#include <limits.h>
#include "util.h"
static char pw_defdir[] = "/etc";
static char *pw_dir = pw_defdir;
static char *pw_lck;
char *
pw_file(const char *nm)
{
const char *p = strrchr(nm, '/');
char *new_nm;
if (p)
p++;
else
p = nm;
if (asprintf(&new_nm, "%s/%s", pw_dir, p) == -1)
return NULL;
return new_nm;
}
void
pw_setdir(const char *dir)
{
char *p;
if (strcmp (dir, pw_dir) == 0)
return;
if (pw_dir != pw_defdir)
free(pw_dir);
pw_dir = strdup(dir);
if (pw_lck) {
p = pw_file(pw_lck);
free(pw_lck);
pw_lck = p;
}
}
int
pw_lock(int retries)
{
int i, fd;
mode_t old_mode;
int save_errno;
if (!pw_lck) {
errno = EINVAL;
return (-1);
}
/* Acquire the lock file. */
old_mode = umask(0);
fd = open(pw_lck, O_WRONLY|O_CREAT|O_EXCL, 0600);
for (i = 0; i < retries && fd < 0 && errno == EEXIST; i++) {
sleep(1);
fd = open(pw_lck, O_WRONLY|O_CREAT|O_EXCL, 0600);
}
save_errno = errno;
if (fd != -1 && fcntl(fd, F_SETFD, 1) == -1) {
close(fd);
fd = -1;
}
(void) umask(old_mode);
errno = save_errno;
return (fd);
}
int
pw_mkdb(char *username, int flags)
{
int pstat, ac;
pid_t pid;
char *av[8];
struct stat sb;
if (pw_lck == NULL)
return(-1);
/* A zero length passwd file is never ok */
if (stat(pw_lck, &sb) == 0 && sb.st_size == 0) {
warnx("%s is zero length", pw_lck);
return (-1);
}
ac = 0;
av[ac++] = "pwd_mkdb";
av[ac++] = "-d";
av[ac++] = pw_dir;
if (flags & _PASSWORD_SECUREONLY)
av[ac++] = "-s";
else if (!(flags & _PASSWORD_OMITV7))
av[ac++] = "-p";
if (username) {
av[ac++] = "-u";
av[ac++] = username;
}
av[ac++] = pw_lck;
av[ac] = NULL;
pid = vfork();
if (pid == -1)
return (-1);
if (pid == 0) {
if (pw_lck)
execv(_PATH_PWD_MKDB, av);
_exit(1);
}
pid = waitpid(pid, &pstat, 0);
if (pid == -1 || !WIFEXITED(pstat) || WEXITSTATUS(pstat) != 0)
return (-1);
return (0);
}
int
pw_abort(void)
{
return (pw_lck ? unlink(pw_lck) : -1);
}
/* Everything below this point is intended for the convenience of programs
* which allow a user to interactively edit the passwd file. Errors in the
* routines below will cause the process to abort. */
static pid_t editpid = -1;
static void
pw_cont(int signo)
{
int save_errno = errno;
if (editpid != -1)
kill(editpid, signo);
errno = save_errno;
}
void
pw_init(void)
{
struct rlimit rlim;
/* Unlimited resource limits. */
rlim.rlim_cur = rlim.rlim_max = RLIM_INFINITY;
(void)setrlimit(RLIMIT_CPU, &rlim);
(void)setrlimit(RLIMIT_FSIZE, &rlim);
(void)setrlimit(RLIMIT_STACK, &rlim);
(void)setrlimit(RLIMIT_DATA, &rlim);
(void)setrlimit(RLIMIT_RSS, &rlim);
/* Don't drop core (not really necessary, but GP's). */
rlim.rlim_cur = rlim.rlim_max = 0;
(void)setrlimit(RLIMIT_CORE, &rlim);
/* Turn off signals. */
(void)signal(SIGALRM, SIG_IGN);
(void)signal(SIGHUP, SIG_IGN);
(void)signal(SIGINT, SIG_IGN);
(void)signal(SIGPIPE, SIG_IGN);
(void)signal(SIGQUIT, SIG_IGN);
(void)signal(SIGTERM, SIG_IGN);
(void)signal(SIGCONT, pw_cont);
if (!pw_lck)
pw_lck = pw_file(_PATH_MASTERPASSWD_LOCK);
}
void
pw_edit(int notsetuid, const char *filename)
{
int pstat;
char *p;
char * volatile editor;
char *argp[] = {"sh", "-c", NULL, NULL};
if (!filename) {
filename = pw_lck;
if (!filename)
return;
}
if ((editor = getenv("EDITOR")) == NULL)
editor = _PATH_VI;
if (asprintf(&p, "%s %s", editor, filename) == -1)
return;
argp[2] = p;
switch (editpid = vfork()) {
case -1: /* error */
free(p);
return;
case 0: /* child */
if (notsetuid) {
setgid(getgid());
setuid(getuid());
}
execv(_PATH_BSHELL, argp);
_exit(127);
}
free(p);
for (;;) {
editpid = waitpid(editpid, (int *)&pstat, WUNTRACED);
if (editpid == -1)
pw_error(editor, 1, 1);
else if (WIFSTOPPED(pstat))
raise(WSTOPSIG(pstat));
else if (WIFEXITED(pstat) && WEXITSTATUS(pstat) == 0)
break;
else
pw_error(editor, 1, 1);
}
editpid = -1;
}
void
pw_prompt(void)
{
int first, c;
(void)printf("re-edit the password file? [y]: ");
(void)fflush(stdout);
first = c = getchar();
while (c != '\n' && c != EOF)
c = getchar();
switch (first) {
case EOF:
putchar('\n');
/* FALLTHROUGH */
case 'n':
case 'N':
pw_error(NULL, 0, 0);
break;
}
}
static int
pw_equal(const struct passwd *pw1, const struct passwd *pw2)
{
return (strcmp(pw1->pw_name, pw2->pw_name) == 0 &&
pw1->pw_uid == pw2->pw_uid &&
pw1->pw_gid == pw2->pw_gid &&
strcmp(pw1->pw_class, pw2->pw_class) == 0 &&
pw1->pw_change == pw2->pw_change &&
pw1->pw_expire == pw2->pw_expire &&
strcmp(pw1->pw_gecos, pw2->pw_gecos) == 0 &&
strcmp(pw1->pw_dir, pw2->pw_dir) == 0 &&
strcmp(pw1->pw_shell, pw2->pw_shell) == 0);
}
void
pw_copy(int ffd, int tfd, const struct passwd *pw, const struct passwd *opw)
{
struct passwd tpw;
FILE *from, *to;
int done;
char *p, *ep, buf[8192];
char *master = pw_file(_PATH_MASTERPASSWD);
if (!master)
pw_error(NULL, 0, 1);
if (!(from = fdopen(ffd, "r")))
pw_error(master, 1, 1);
if (!(to = fdopen(tfd, "w")))
pw_error(pw_lck ? pw_lck : NULL, pw_lck ? 1 : 0, 1);
for (done = 0; fgets(buf, (int)sizeof(buf), from);) {
if ((ep = strchr(buf, '\n')) == NULL) {
warnx("%s: line too long", master);
pw_error(NULL, 0, 1);
}
if (done) {
(void)fprintf(to, "%s", buf);
if (ferror(to))
goto fail;
continue;
}
if (!(p = strchr(buf, ':'))) {
warnx("%s: corrupted entry", master);
pw_error(NULL, 0, 1);
}
*p = '\0';
if (strcmp(buf, opw ? opw->pw_name : pw->pw_name)) {
*p = ':';
(void)fprintf(to, "%s", buf);
if (ferror(to))
goto fail;
continue;
}
if (opw != NULL) {
*p = ':';
*ep = '\0';
if (!pw_scan(buf, &tpw, NULL))
pw_error(NULL, 0, 1);
if (!pw_equal(&tpw, opw)) {
warnx("%s: inconsistent entry", master);
pw_error(NULL, 0, 1);
}
}
(void)fprintf(to, "%s:%s:%u:%u:%s:%d:%d:%s:%s:%s\n",
pw->pw_name, pw->pw_passwd, (u_int)pw->pw_uid,
(u_int)pw->pw_gid, pw->pw_class, pw->pw_change,
pw->pw_expire, pw->pw_gecos, pw->pw_dir,
pw->pw_shell);
done = 1;
if (ferror(to))
goto fail;
}
if (!done)
(void)fprintf(to, "%s:%s:%d:%d:%s:%d:%d:%s:%s:%s\n",
pw->pw_name, pw->pw_passwd, pw->pw_uid, pw->pw_gid,
pw->pw_class, pw->pw_change, pw->pw_expire, pw->pw_gecos,
pw->pw_dir, pw->pw_shell);
if (ferror(to))
fail:
pw_error(NULL, 0, 1);
free(master);
(void)fclose(to);
}
int
pw_scan(char *bp, struct passwd *pw, int *flags)
{
u_long id;
int root;
char *p, *sh, *p2;
if (flags != (int *)NULL)
*flags = 0;
if (!(p = strsep(&bp, ":")) || *p == '\0') /* login */
goto fmt;
pw->pw_name = p;
root = !strcmp(pw->pw_name, "root");
if (!(pw->pw_passwd = strsep(&bp, ":"))) /* passwd */
goto fmt;
if (!(p = strsep(&bp, ":"))) /* uid */
goto fmt;
id = strtoul(p, &p2, 10);
if (root && id) {
warnx("root uid should be 0");
return (0);
}
if (*p2 != '\0') {
warnx("illegal uid field");
return (0);
}
if (id > UID_MAX) {
/* errno is set to ERANGE by strtoul(3) */
warnx("uid greater than %u", UID_MAX-1);
return (0);
}
pw->pw_uid = (uid_t)id;
if ((*p == '\0') && (flags != (int *)NULL))
*flags |= _PASSWORD_NOUID;
if (!(p = strsep(&bp, ":"))) /* gid */
goto fmt;
id = strtoul(p, &p2, 10);
if (*p2 != '\0') {
warnx("illegal gid field");
return (0);
}
if (id > UID_MAX) {
/* errno is set to ERANGE by strtoul(3) */
warnx("gid greater than %u", UID_MAX-1);
return (0);
}
pw->pw_gid = (gid_t)id;
if ((*p == '\0') && (flags != (int *)NULL))
*flags |= _PASSWORD_NOGID;
pw->pw_class = strsep(&bp, ":"); /* class */
if (!(p = strsep(&bp, ":"))) /* change */
goto fmt;
pw->pw_change = atol(p);
if ((*p == '\0') && (flags != (int *)NULL))
*flags |= _PASSWORD_NOCHG;
if (!(p = strsep(&bp, ":"))) /* expire */
goto fmt;
pw->pw_expire = atol(p);
if ((*p == '\0') && (flags != (int *)NULL))
*flags |= _PASSWORD_NOEXP;
pw->pw_gecos = strsep(&bp, ":"); /* gecos */
pw->pw_dir = strsep(&bp, ":"); /* directory */
if (!(pw->pw_shell = strsep(&bp, ":"))) /* shell */
goto fmt;
p = pw->pw_shell;
if (root && *p) { /* empty == /bin/sh */
for (setusershell();;) {
if (!(sh = getusershell())) {
warnx("warning, unknown root shell");
break;
}
if (!strcmp(p, sh))
break;
}
endusershell();
}
if ((p = strsep(&bp, ":"))) { /* too many */
fmt: warnx("corrupted entry");
return (0);
}
return (1);
}
__dead void
pw_error(const char *name, int error, int eval)
{
char *master = pw_file(_PATH_MASTERPASSWD);
if (error) {
if (name)
warn("%s", name);
else
warn(NULL);
}
if (master) {
warnx("%s: unchanged", master);
free(master);
}
pw_abort();
exit(eval);
}