linux/fs/dlm/netlink.c

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/*
* Copyright (C) 2007 Red Hat, Inc. All rights reserved.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU General Public License v.2.
*/
#include <net/genetlink.h>
#include <linux/dlm.h>
#include <linux/dlm_netlink.h>
#include "dlm_internal.h"
static uint32_t dlm_nl_seqnum;
static uint32_t listener_nlpid;
static struct genl_family family = {
.id = GENL_ID_GENERATE,
.name = DLM_GENL_NAME,
.version = DLM_GENL_VERSION,
};
static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
{
struct sk_buff *skb;
void *data;
skb = genlmsg_new(size, GFP_KERNEL);
if (!skb)
return -ENOMEM;
/* add the message headers */
data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
if (!data) {
nlmsg_free(skb);
return -EINVAL;
}
*skbp = skb;
return 0;
}
static struct dlm_lock_data *mk_data(struct sk_buff *skb)
{
struct nlattr *ret;
ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
if (!ret)
return NULL;
return nla_data(ret);
}
static int send_data(struct sk_buff *skb)
{
struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
void *data = genlmsg_data(genlhdr);
int rv;
rv = genlmsg_end(skb, data);
if (rv < 0) {
nlmsg_free(skb);
return rv;
}
genetlink: make netns aware This makes generic netlink network namespace aware. No generic netlink families except for the controller family are made namespace aware, they need to be checked one by one and then set the family->netnsok member to true. A new function genlmsg_multicast_netns() is introduced to allow sending a multicast message in a given namespace, for example when it applies to an object that lives in that namespace, a new function genlmsg_multicast_allns() to send a message to all network namespaces (for objects that do not have an associated netns). The function genlmsg_multicast() is changed to multicast the message in just init_net, which is currently correct for all generic netlink families since they only work in init_net right now. Some will later want to work in all net namespaces because they do not care about the netns at all -- those will have to be converted to use one of the new functions genlmsg_multicast_allns() or genlmsg_multicast_netns() whenever they are made netns aware in some way. After this patch families can easily decide whether or not they should be available in all net namespaces. Many genl families us it for objects not related to networking and should therefore be available in all namespaces, but that will have to be done on a per family basis. Note that this doesn't touch on the checkpoint/restart problem where network namespaces could be used, genl families and multicast groups are numbered globally and I see no easy way of changing that, especially since it must be possible to multicast to all network namespaces for those families that do not care about netns. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-10 11:51:34 +02:00
return genlmsg_unicast(&init_net, skb, listener_nlpid);
}
static int user_cmd(struct sk_buff *skb, struct genl_info *info)
{
listener_nlpid = info->snd_pid;
printk("user_cmd nlpid %u\n", listener_nlpid);
return 0;
}
static struct genl_ops dlm_nl_ops = {
.cmd = DLM_CMD_HELLO,
.doit = user_cmd,
};
int __init dlm_netlink_init(void)
{
int rv;
rv = genl_register_family(&family);
if (rv)
return rv;
rv = genl_register_ops(&family, &dlm_nl_ops);
if (rv < 0)
goto err;
return 0;
err:
genl_unregister_family(&family);
return rv;
}
void dlm_netlink_exit(void)
{
genl_unregister_ops(&family, &dlm_nl_ops);
genl_unregister_family(&family);
}
static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
{
struct dlm_rsb *r = lkb->lkb_resource;
memset(data, 0, sizeof(struct dlm_lock_data));
data->version = DLM_LOCK_DATA_VERSION;
data->nodeid = lkb->lkb_nodeid;
data->ownpid = lkb->lkb_ownpid;
data->id = lkb->lkb_id;
data->remid = lkb->lkb_remid;
data->status = lkb->lkb_status;
data->grmode = lkb->lkb_grmode;
data->rqmode = lkb->lkb_rqmode;
if (lkb->lkb_ua)
data->xid = lkb->lkb_ua->xid;
if (r) {
data->lockspace_id = r->res_ls->ls_global_id;
data->resource_namelen = r->res_length;
memcpy(data->resource_name, r->res_name, r->res_length);
}
}
void dlm_timeout_warn(struct dlm_lkb *lkb)
{
struct sk_buff *uninitialized_var(send_skb);
struct dlm_lock_data *data;
size_t size;
int rv;
size = nla_total_size(sizeof(struct dlm_lock_data)) +
nla_total_size(0); /* why this? */
rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
if (rv < 0)
return;
data = mk_data(send_skb);
if (!data) {
nlmsg_free(send_skb);
return;
}
fill_data(data, lkb);
send_data(send_skb);
}