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/*
* Copyright (c) 2010 Tomas Mraz <tmraz@redhat.com>
* Copyright (c) 2010, 2016, 2017 Red Hat, Inc.
*
* 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, and the entire permission notice in its entirety,
* including the disclaimer of warranties.
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* ALTERNATIVELY, this product may be distributed under the terms of
* the GNU Public License, in which case the provisions of the GPL are
* required INSTEAD OF the above restrictions. (This clause is
* necessary due to a potential bad interaction between the GPL and
* the restrictions contained in a BSD-style copyright.)
*
* THIS SOFTWARE IS PROVIDED ``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 AUTHOR 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 "config.h"
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <security/pam_modutil.h>
#include "faillock.h"
#define ignore_return(x) if (1==((int)x)) {;}
int
open_tally (const char *dir, const char *user, uid_t uid, int create)
{
char *path;
int flags = O_RDWR;
int fd;
if (dir == NULL || strstr(user, "../") != NULL)
/* just a defensive programming as the user must be a
* valid user on the system anyway
*/
return -1;
path = malloc(strlen(dir) + strlen(user) + 2);
if (path == NULL)
return -1;
strcpy(path, dir);
if (*dir && dir[strlen(dir) - 1] != '/') {
strcat(path, "/");
}
strcat(path, user);
if (create) {
flags |= O_CREAT;
}
fd = open(path, flags, 0660);
free(path);
if (fd != -1) {
struct stat st;
while (flock(fd, LOCK_EX) == -1 && errno == EINTR);
if (fstat(fd, &st) == 0) {
if (st.st_uid != uid) {
ignore_return(fchown(fd, uid, -1));
}
/*
* If umask is set to 022, as will probably in most systems, then the
* group will not be able to write to the file. So, change the file
* permissions just in case.
* Note: owners of this file are user:root, so if the permissions are
* not changed the root process writing to this file will require
* CAP_DAC_OVERRIDE.
*/
if (!(st.st_mode & S_IWGRP)) {
ignore_return(fchmod(fd, 0660));
}
}
}
return fd;
}
#define CHUNK_SIZE (64 * sizeof(struct tally))
#define MAX_RECORDS 1024
int
read_tally(int fd, struct tally_data *tallies)
{
void *data = NULL, *newdata;
unsigned int count = 0;
ssize_t chunk = 0;
do {
newdata = realloc(data, count * sizeof(struct tally) + CHUNK_SIZE);
if (newdata == NULL) {
free(data);
return -1;
}
data = newdata;
chunk = pam_modutil_read(fd, (char *)data + count * sizeof(struct tally), CHUNK_SIZE);
if (chunk < 0) {
free(data);
return -1;
}
count += chunk/sizeof(struct tally);
if (count >= MAX_RECORDS)
break;
}
while (chunk == CHUNK_SIZE);
tallies->records = data;
tallies->count = count;
return 0;
}
int
update_tally(int fd, struct tally_data *tallies)
{
void *data = tallies->records;
unsigned int count = tallies->count;
ssize_t chunk;
if (tallies->count > MAX_RECORDS) {
data = tallies->records + (count - MAX_RECORDS);
count = MAX_RECORDS;
}
if (lseek(fd, 0, SEEK_SET) == (off_t)-1) {
return -1;
}
chunk = pam_modutil_write(fd, data, count * sizeof(struct tally));
if (chunk != (ssize_t)(count * sizeof(struct tally))) {
return -1;
}
if (ftruncate(fd, count * sizeof(struct tally)) == -1)
return -1;
return 0;
}
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