githubmirror/audit-userspace

src/ausearch-int.c
184 строки4 KB
Steve Grubb
aureport: preserve integer lists on allocation failure
13 июл 2026, 05:08
13 июл 2026, 05:08ec5fafa
/*
* ausearch-int.c - Minimal linked list library for integers
* Copyright (c) 2005,2008 Red Hat Inc.
* All Rights Reserved. 
*
* This software may be freely redistributed and/or modified under the
* terms of the GNU General Public License as published by the Free
* Software Foundation; either version 2, or (at your option) any
* later version.
*
* 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; see the file COPYING. If not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor 
* Boston, MA 02110-1335, USA.
*
* Authors:
*   Steve Grubb <sgrubb@redhat.com>
*/

#include "config.h"
#include <stdlib.h>
#include "ausearch-int.h"

void ilist_create(ilist *l)
{
	l->head = NULL;
	l->cur = NULL;
	l->cnt = 0;
}

int_node *ilist_next(ilist *l)
{
	if (l->cur == NULL)
		return NULL;
	l->cur = l->cur->next;
	return l->cur;
}

/*
 * ilist_alloc_node - allocate and initialize an integer list node
 * @num: integer to store
 * @hits: initial occurrence count
 * @aux: auxiliary value to store
 *
 * Returns: Allocated node, or NULL on allocation failure.
 */
static int_node *ilist_alloc_node(int num, unsigned int hits, int aux)
{
	int_node *newnode;

	newnode = malloc(sizeof(int_node));
	if (newnode == NULL)
		return NULL;

	newnode->num = num;
	newnode->hits = hits;
	newnode->aux1 = aux;
	newnode->next = NULL;
	return newnode;
}

int ilist_append(ilist *l, int num, unsigned int hits, int aux)
{
	int_node* newnode;

	newnode = ilist_alloc_node(num, hits, aux);
	if (newnode == NULL)
		return 1;

	// if we are at top, fix this up
	if (l->head == NULL)
		l->head = newnode;
	else	// Otherwise add pointer to newnode
		l->cur->next = newnode;

	// make newnode current
	l->cur = newnode;
	l->cnt++;

	return 0;
}

void ilist_clear(ilist* l)
{
	int_node* nextnode;
	register int_node* current;

	if (l == NULL)
		return;

	current = l->head;
	while (current) {
		nextnode=current->next;
		free(current);
		current=nextnode;
	}
	l->head = NULL;
	l->cur = NULL;
	l->cnt = 0;
}

int ilist_add_if_uniq(ilist *l, int num, int aux)
{
	register int_node *cur, *prev;
	int_node *newnode;

	prev = cur = l->head;
	while (cur) {
		if (cur->num == num) {
			cur->hits++;
			return 0;
		} else if (num > cur->num) {
			prev = cur;
			cur = cur->next;
		} else {
			newnode = ilist_alloc_node(num, 1, aux);
			if (newnode == NULL)
				return -1;

			// Link after alloc so failed insert leaves l intact
			newnode->next = cur;
			if (cur == l->head)
				l->head = newnode;
			else
				prev->next = newnode;
			l->cur = newnode;
			l->cnt++;
			return 1;
		}
	}

	if (prev)
		l->cur = prev;

	/* No matches, append to the end */
	if (ilist_append(l, num, 1, aux))
		return -1;
	return 1;
}

// If lprev would be NULL, use l->head
static void swap_nodes(int_node *lprev, int_node *left, int_node *right)
{
	int_node *t = right->next;
	if (lprev)
		lprev->next = right;
	right->next = left;
	left->next = t;
}

// This will sort the list from most hits to least
void ilist_sort_by_hits(ilist *l)
{
	register int_node* cur, *prev;

	if (l->cnt <= 1)
		return;

	prev = cur = l->head;
	while (cur && cur->next) {
		/* If the next node is bigger */
		if (cur->hits < cur->next->hits) {
			if (cur == l->head) {
				// Update the actual list head
				l->head = cur->next;
				prev = NULL;
			}
			swap_nodes(prev, cur, cur->next);

			// start over
			prev = cur = l->head;
			continue;
		}
		prev = cur;
		cur = cur->next;
	}
	// End with cur pointing at first record
	l->cur = l->head;
}