/**
* @file
*
* @brief User Database Access Routines
* @ingroup libcsupport
*/
/*
* Copyright (c) 1999-2009 Ralf Corsepius <corsepiu@faw.uni-ulm.de>
* Copyright (c) 1999-2013 Joel Sherrill <joel.sherrill@OARcorp.com>
* Copyright (c) 2000-2001 Fernando Ruiz Casas <fruizcasas@gmail.com>
* Copyright (c) 2002 Eric Norum <eric@norum.ca>
* Copyright (c) 2003 Till Straumann <strauman@slac.stanford.edu>
* Copyright (c) 2012 Alex Ivanov <alexivanov97@gmail.com>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/stat.h>
#include <pwd.h>
#include <grp.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <ctype.h>
#include <pthread.h>
#include <stdint.h>
#include <rtems/seterr.h>
#include <rtems/score/assert.h>
#include "pwdgrp.h"
static pthread_once_t pwdgrp_once = PTHREAD_ONCE_INIT;
static void init_file(const char *name, const char *content)
{
/*
* Unlike to standard UNIX systems, these files are only readable and
* writeable for the root user. This way we avoid the need for an
* /etc/shadow. In case more UNIX compatibility is desired, this can be
* added on demand.
*/
int fd = open(name, O_CREAT | O_EXCL | O_WRONLY, S_IRUSR | S_IWUSR);
if (fd >= 0) {
write(fd, content, strlen(content));
close(fd);
}
}
/**
* Initialize useable but dummy databases
*/
static void pwdgrp_init(void)
{
/*
* Do the best to create this directory.
*
* /etc could be created by the network stack initialization or an initial
* filesystem image. Deliberately ignore the return value.
*/
(void) mkdir("/etc", S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH);
/*
* Initialize /etc/passwd
*/
init_file("/etc/passwd", "root::0:0::::\n");
/*
* Initialize /etc/group
*/
init_file("/etc/group", "root::0:\n");
}
void _libcsupport_pwdgrp_init(void)
{
pthread_once(&pwdgrp_once, pwdgrp_init);
}
/**
* Extract a string value from the database
*/
static int
scanString(FILE *fp, char **name, char **bufp, size_t *nleft, int nlFlag)
{
int c;
*name = *bufp;
for (;;) {
c = getc(fp);
if (c == ':') {
if (nlFlag)
return 0;
break;
}
if (c == '\n') {
if (!nlFlag)
return 0;
break;
}
if (c == EOF)
return 0;
if (*nleft < 2)
return 0;
**bufp = c;
++(*bufp);
--(*nleft);
}
**bufp = '\0';
++(*bufp);
--(*nleft);
return 1;
}
/**
* Extract an integer value from the database
*/
static int
scanInt(FILE *fp, int *val)
{
int c;
unsigned int i = 0;
unsigned int limit = INT_MAX;
int sign = 0;
int d;
for (;;) {
c = getc(fp);
if (c == ':')
break;
if (sign == 0) {
if (c == '-') {
sign = -1;
limit++;
continue;
}
sign = 1;
}
if (!isdigit(c))
return 0;
d = c - '0';
if ((i > (limit / 10))
|| ((i == (limit / 10)) && (d > (limit % 10))))
return 0;
i = i * 10 + d;
}
if (sign == 0)
return 0;
*val = i * sign;
return 1;
}
/*
* Extract a single password record from the database
*/
int _libcsupport_scanpw(
FILE *fp,
struct passwd *pwd,
char *buffer,
size_t bufsize
)
{
int pwuid, pwgid;
if (!scanString(fp, &pwd->pw_name, &buffer, &bufsize, 0)
|| !scanString(fp, &pwd->pw_passwd, &buffer, &bufsize, 0)
|| !scanInt(fp, &pwuid)
|| !scanInt(fp, &pwgid)
|| !scanString(fp, &pwd->pw_comment, &buffer, &bufsize, 0)
|| !scanString(fp, &pwd->pw_gecos, &buffer, &bufsize, 0)
|| !scanString(fp, &pwd->pw_dir, &buffer, &bufsize, 0)
|| !scanString(fp, &pwd->pw_shell, &buffer, &bufsize, 1))
return 0;
pwd->pw_uid = pwuid;
pwd->pw_gid = pwgid;
return 1;
}
static int getpw_r(
const char *name,
int uid,
struct passwd *pwd,
char *buffer,
size_t bufsize,
struct passwd **result
)
{
FILE *fp;
int match;
_libcsupport_pwdgrp_init();
if ((fp = fopen("/etc/passwd", "r")) == NULL)
rtems_set_errno_and_return_minus_one( EINVAL );
for(;;) {
if (!_libcsupport_scanpw(fp, pwd, buffer, bufsize))
goto error_einval;
if (name) {
match = (strcmp(pwd->pw_name, name) == 0);
} else {
match = (pwd->pw_uid == uid);
}
if (match) {
fclose(fp);
*result = pwd;
return 0;
}
}
error_einval:
fclose(fp);
rtems_set_errno_and_return_minus_one( EINVAL );
}
int getpwnam_r(
const char *name,
struct passwd *pwd,
char *buffer,
size_t bufsize,
struct passwd **result
)
{
return getpw_r(name, 0, pwd, buffer, bufsize, result);
}
int getpwuid_r(
uid_t uid,
struct passwd *pwd,
char *buffer,
size_t bufsize,
struct passwd **result
)
{
return getpw_r(NULL, uid, pwd, buffer, bufsize, result);
}
/**
* Extract a single group record from the database
*/
int _libcsupport_scangr(
FILE *fp,
struct group *grp,
char *buffer,
size_t bufsize
)
{
int grgid;
char *grmem, *cp;
int memcount;
if (!scanString(fp, &grp->gr_name, &buffer, &bufsize, 0)
|| !scanString(fp, &grp->gr_passwd, &buffer, &bufsize, 0)
|| !scanInt(fp, &grgid)
|| !scanString(fp, &grmem, &buffer, &bufsize, 1))
return 0;
grp->gr_gid = grgid;
/*
* Determine number of members
*/
if (grmem[0] == '\0') {
memcount = 0;
} else {
for (cp = grmem, memcount = 1 ; *cp != 0 ; cp++) {
if(*cp == ',')
memcount++;
}
}
/*
* Hack to produce (hopefully) a suitably-aligned array of pointers
*/
if (bufsize < (((memcount+1)*sizeof(char *)) + 15))
return 0;
grp->gr_mem = (char **)(((uintptr_t)buffer + 15) & ~15);
/*
* Fill in pointer array
*/
if (grmem[0] == '\0') {
memcount = 0;
} else {
grp->gr_mem[0] = grmem;
for (cp = grmem, memcount = 1 ; *cp != 0 ; cp++) {
if(*cp == ',') {
*cp = '\0';
grp->gr_mem[memcount++] = cp + 1;
}
}
}
grp->gr_mem[memcount] = NULL;
return 1;
}
static int getgr_r(
const char *name,
int gid,
struct group *grp,
char *buffer,
size_t bufsize,
struct group **result
)
{
FILE *fp;
int match;
_libcsupport_pwdgrp_init();
if ((fp = fopen("/etc/group", "r")) == NULL)
rtems_set_errno_and_return_minus_one( EINVAL );
for(;;) {
if (!_libcsupport_scangr(fp, grp, buffer, bufsize))
goto error_einval;
if (name) {
match = (strcmp(grp->gr_name, name) == 0);
} else {
match = (grp->gr_gid == gid);
}
if (match) {
fclose(fp);
*result = grp;
return 0;
}
}
error_einval:
fclose(fp);
rtems_set_errno_and_return_minus_one( EINVAL );
}
int getgrnam_r(
const char *name,
struct group *grp,
char *buffer,
size_t bufsize,
struct group **result
)
{
return getgr_r(name, 0, grp, buffer, bufsize, result);
}
int getgrgid_r(
gid_t gid,
struct group *grp,
char *buffer,
size_t bufsize,
struct group **result
)
{
return getgr_r(NULL, gid, grp, buffer, bufsize, result);
}
