Revision 92a8109e4d3a34fb6b115c9098b51767dc933444 authored by Ross Lagerwall on 08 January 2019, 18:30:56 UTC, committed by Steve French on 11 January 2019, 13:14:40 UTC
The code tries to allocate a contiguous buffer with a size supplied by the server (maxBuf). This could fail if memory is fragmented since it results in high order allocations for commonly used server implementations. It is also wasteful since there are probably few locks in the usual case. Limit the buffer to be no larger than a page to avoid memory allocation failures due to fragmentation. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Steve French <stfrench@microsoft.com>
1 parent 15bc77f
bat_algo.c
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2007-2018 B.A.T.M.A.N. contributors:
*
* Marek Lindner, Simon Wunderlich
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include "main.h"
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#include <linux/netlink.h>
#include <linux/printk.h>
#include <linux/seq_file.h>
#include <linux/skbuff.h>
#include <linux/stddef.h>
#include <linux/string.h>
#include <net/genetlink.h>
#include <net/netlink.h>
#include <uapi/linux/batman_adv.h>
#include "bat_algo.h"
#include "netlink.h"
char batadv_routing_algo[20] = "BATMAN_IV";
static struct hlist_head batadv_algo_list;
/**
* batadv_algo_init() - Initialize batman-adv algorithm management data
* structures
*/
void batadv_algo_init(void)
{
INIT_HLIST_HEAD(&batadv_algo_list);
}
static struct batadv_algo_ops *batadv_algo_get(char *name)
{
struct batadv_algo_ops *bat_algo_ops = NULL, *bat_algo_ops_tmp;
hlist_for_each_entry(bat_algo_ops_tmp, &batadv_algo_list, list) {
if (strcmp(bat_algo_ops_tmp->name, name) != 0)
continue;
bat_algo_ops = bat_algo_ops_tmp;
break;
}
return bat_algo_ops;
}
/**
* batadv_algo_register() - Register callbacks for a mesh algorithm
* @bat_algo_ops: mesh algorithm callbacks to add
*
* Return: 0 on success or negative error number in case of failure
*/
int batadv_algo_register(struct batadv_algo_ops *bat_algo_ops)
{
struct batadv_algo_ops *bat_algo_ops_tmp;
bat_algo_ops_tmp = batadv_algo_get(bat_algo_ops->name);
if (bat_algo_ops_tmp) {
pr_info("Trying to register already registered routing algorithm: %s\n",
bat_algo_ops->name);
return -EEXIST;
}
/* all algorithms must implement all ops (for now) */
if (!bat_algo_ops->iface.enable ||
!bat_algo_ops->iface.disable ||
!bat_algo_ops->iface.update_mac ||
!bat_algo_ops->iface.primary_set ||
!bat_algo_ops->neigh.cmp ||
!bat_algo_ops->neigh.is_similar_or_better) {
pr_info("Routing algo '%s' does not implement required ops\n",
bat_algo_ops->name);
return -EINVAL;
}
INIT_HLIST_NODE(&bat_algo_ops->list);
hlist_add_head(&bat_algo_ops->list, &batadv_algo_list);
return 0;
}
/**
* batadv_algo_select() - Select algorithm of soft interface
* @bat_priv: the bat priv with all the soft interface information
* @name: name of the algorithm to select
*
* The algorithm callbacks for the soft interface will be set when the algorithm
* with the correct name was found. Any previous selected algorithm will not be
* deinitialized and the new selected algorithm will also not be initialized.
* It is therefore not allowed to call batadv_algo_select outside the creation
* function of the soft interface.
*
* Return: 0 on success or negative error number in case of failure
*/
int batadv_algo_select(struct batadv_priv *bat_priv, char *name)
{
struct batadv_algo_ops *bat_algo_ops;
bat_algo_ops = batadv_algo_get(name);
if (!bat_algo_ops)
return -EINVAL;
bat_priv->algo_ops = bat_algo_ops;
return 0;
}
#ifdef CONFIG_BATMAN_ADV_DEBUGFS
/**
* batadv_algo_seq_print_text() - Print the supported algorithms in a seq file
* @seq: seq file to print on
* @offset: not used
*
* Return: always 0
*/
int batadv_algo_seq_print_text(struct seq_file *seq, void *offset)
{
struct batadv_algo_ops *bat_algo_ops;
seq_puts(seq, "Available routing algorithms:\n");
hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
seq_printf(seq, " * %s\n", bat_algo_ops->name);
}
return 0;
}
#endif
static int batadv_param_set_ra(const char *val, const struct kernel_param *kp)
{
struct batadv_algo_ops *bat_algo_ops;
char *algo_name = (char *)val;
size_t name_len = strlen(algo_name);
if (name_len > 0 && algo_name[name_len - 1] == '\n')
algo_name[name_len - 1] = '\0';
bat_algo_ops = batadv_algo_get(algo_name);
if (!bat_algo_ops) {
pr_err("Routing algorithm '%s' is not supported\n", algo_name);
return -EINVAL;
}
return param_set_copystring(algo_name, kp);
}
static const struct kernel_param_ops batadv_param_ops_ra = {
.set = batadv_param_set_ra,
.get = param_get_string,
};
static struct kparam_string batadv_param_string_ra = {
.maxlen = sizeof(batadv_routing_algo),
.string = batadv_routing_algo,
};
module_param_cb(routing_algo, &batadv_param_ops_ra, &batadv_param_string_ra,
0644);
/**
* batadv_algo_dump_entry() - fill in information about one supported routing
* algorithm
* @msg: netlink message to be sent back
* @portid: Port to reply to
* @seq: Sequence number of message
* @bat_algo_ops: Algorithm to be dumped
*
* Return: Error number, or 0 on success
*/
static int batadv_algo_dump_entry(struct sk_buff *msg, u32 portid, u32 seq,
struct batadv_algo_ops *bat_algo_ops)
{
void *hdr;
hdr = genlmsg_put(msg, portid, seq, &batadv_netlink_family,
NLM_F_MULTI, BATADV_CMD_GET_ROUTING_ALGOS);
if (!hdr)
return -EMSGSIZE;
if (nla_put_string(msg, BATADV_ATTR_ALGO_NAME, bat_algo_ops->name))
goto nla_put_failure;
genlmsg_end(msg, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(msg, hdr);
return -EMSGSIZE;
}
/**
* batadv_algo_dump() - fill in information about supported routing
* algorithms
* @msg: netlink message to be sent back
* @cb: Parameters to the netlink request
*
* Return: Length of reply message.
*/
int batadv_algo_dump(struct sk_buff *msg, struct netlink_callback *cb)
{
int portid = NETLINK_CB(cb->skb).portid;
struct batadv_algo_ops *bat_algo_ops;
int skip = cb->args[0];
int i = 0;
hlist_for_each_entry(bat_algo_ops, &batadv_algo_list, list) {
if (i++ < skip)
continue;
if (batadv_algo_dump_entry(msg, portid, cb->nlh->nlmsg_seq,
bat_algo_ops)) {
i--;
break;
}
}
cb->args[0] = i;
return msg->len;
}
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