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systemd/klibc_fixups.c
kay.sievers@vrfy.org c81b35c08b [PATCH] replace fgets() with mmap() and introduce udev_lib.[hc]
Here we replace the various fgets() with a mmap() call for the config
file reading, due to the reported performance problems with klibc.

Thanks to Patrick's testing, it makes a very small, close to nothing
speed gain for libc users, but a 6 times speed increase for klibc users
with a 1000 line config file.

I've created a udev_lib.[hc] for this and also moved all the generic
stuff from udev.h in there and uninlined the functions.
2005-04-26 21:35:10 -07:00

162 lines
3.1 KiB
C

/*
* klibc_fixups.c - very simple implementation of stuff missing in klibc
*
* Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
*
* 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 version 2 of the License.
*
* 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.
*
*/
#ifdef __KLIBC__
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/types.h>
#include "udev.h"
#include "klibc_fixups.h"
#include "logging.h"
#define PW_FILE "/etc/passwd"
#define GR_FILE "/etc/group"
#define UTMP_FILE "/var/run/utmp"
/* return the id of a passwd style line, selected by the users name */
static unsigned long get_id_by_name(const char *uname, const char *dbfile)
{
unsigned long id = -1;
char line[255];
char *buf;
size_t bufsize;
size_t cur;
size_t count;
char *pos;
char *name;
char *idstr;
char *tail;
if (file_map(dbfile, &buf, &bufsize) == 0) {
dbg("reading '%s' as db file", dbfile);
} else {
dbg("can't open '%s' as db file", dbfile);
return -1;
}
/* loop through the whole file */
cur = 0;
while (1) {
count = buf_get_line(buf, bufsize, cur);
strncpy(line, buf + cur, count);
line[count] = '\0';
pos = line;
cur += count+1;
if (cur > bufsize)
break;
/* get name */
name = strsep(&pos, ":");
if (name == NULL)
continue;
/* skip pass */
if (strsep(&pos, ":") == NULL)
continue;
/* get id */
idstr = strsep(&pos, ":");
if (idstr == NULL)
continue;
if (strcmp(uname, name) == 0) {
id = strtoul(idstr, &tail, 10);
if (tail[0] != '\0')
id = -1;
else
dbg("id for '%s' is '%li'", name, id);
break;
}
}
file_unmap(buf, bufsize);
return id;
}
struct passwd *getpwnam(const char *name)
{
static struct passwd pw;
memset(&pw, 0x00, sizeof(struct passwd));
pw.pw_uid = (uid_t) get_id_by_name(name, PW_FILE);
if (pw.pw_uid < 0)
return NULL;
else
return &pw;
}
struct group *getgrnam(const char *name)
{
static struct group gr;
memset(&gr, 0x00, sizeof(struct group));
gr.gr_gid = (gid_t) get_id_by_name(name, GR_FILE);
if (gr.gr_gid < 0)
return NULL;
else
return &gr;
}
int ufd = -1;
void setutent()
{
if (ufd < 0)
ufd = open(UTMP_FILE, O_RDONLY);
fcntl(ufd, F_SETFD, FD_CLOEXEC);
lseek(ufd, 0, SEEK_SET);
}
void endutent() {
if (ufd < 0)
return;
close(ufd);
ufd = -1;
}
struct utmp *getutent(void)
{
static struct utmp utmp;
int retval;
if (ufd < 0) {
setutent();
if (ufd < 0)
return NULL;
}
retval = read(ufd, &utmp, sizeof(struct utmp));
if (retval < 1)
return NULL;
return &utmp;
}
#endif