LXR linux/fs/dlm/netlink.c

   1/*
   2 * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
   3 *
   4 * This copyrighted material is made available to anyone wishing to use,
   5 * modify, copy, or redistribute it subject to the terms and conditions
   6 * of the GNU General Public License v.2.
   7 */
   8
   9#include <net/genetlink.h>
  10#include <linux/dlm.h>
  11#include <linux/dlm_netlink.h>
  12#include <linux/gfp.h>
  13
  14#include "dlm_internal.h"
  15
  16static uint32_t dlm_nl_seqnum;
  17static uint32_t listener_nlpid;
  18
  19static struct genl_family family = {
  20        .id             = GENL_ID_GENERATE,
  21        .name           = DLM_GENL_NAME,
  22        .version        = DLM_GENL_VERSION,
  23};
  24
  25static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
  26{
  27        struct sk_buff *skb;
  28        void *data;
  29
  30        skb = genlmsg_new(size, GFP_NOFS);
  31        if (!skb)
  32                return -ENOMEM;
  33
  34        /* add the message headers */
  35        data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
  36        if (!data) {
  37                nlmsg_free(skb);
  38                return -EINVAL;
  39        }
  40
  41        *skbp = skb;
  42        return 0;
  43}
  44
  45static struct dlm_lock_data *mk_data(struct sk_buff *skb)
  46{
  47        struct nlattr *ret;
  48
  49        ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
  50        if (!ret)
  51                return NULL;
  52        return nla_data(ret);
  53}
  54
  55static int send_data(struct sk_buff *skb)
  56{
  57        struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
  58        void *data = genlmsg_data(genlhdr);
  59        int rv;
  60
  61        rv = genlmsg_end(skb, data);
  62        if (rv < 0) {
  63                nlmsg_free(skb);
  64                return rv;
  65        }
  66
  67        return genlmsg_unicast(&init_net, skb, listener_nlpid);
  68}
  69
  70static int user_cmd(struct sk_buff *skb, struct genl_info *info)
  71{
  72        listener_nlpid = info->snd_pid;
  73        printk("user_cmd nlpid %u\n", listener_nlpid);
  74        return 0;
  75}
  76
  77static struct genl_ops dlm_nl_ops = {
  78        .cmd            = DLM_CMD_HELLO,
  79        .doit           = user_cmd,
  80};
  81
  82int __init dlm_netlink_init(void)
  83{
  84        return genl_register_family_with_ops(&family, &dlm_nl_ops, 1);
  85}
  86
  87void dlm_netlink_exit(void)
  88{
  89        genl_unregister_family(&family);
  90}
  91
  92static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
  93{
  94        struct dlm_rsb *r = lkb->lkb_resource;
  95
  96        memset(data, 0, sizeof(struct dlm_lock_data));
  97
  98        data->version = DLM_LOCK_DATA_VERSION;
  99        data->nodeid = lkb->lkb_nodeid;
 100        data->ownpid = lkb->lkb_ownpid;
 101        data->id = lkb->lkb_id;
 102        data->remid = lkb->lkb_remid;
 103        data->status = lkb->lkb_status;
 104        data->grmode = lkb->lkb_grmode;
 105        data->rqmode = lkb->lkb_rqmode;
 106        if (lkb->lkb_ua)
 107                data->xid = lkb->lkb_ua->xid;
 108        if (r) {
 109                data->lockspace_id = r->res_ls->ls_global_id;
 110                data->resource_namelen = r->res_length;
 111                memcpy(data->resource_name, r->res_name, r->res_length);
 112        }
 113}
 114
 115void dlm_timeout_warn(struct dlm_lkb *lkb)
 116{
 117        struct sk_buff *uninitialized_var(send_skb);
 118        struct dlm_lock_data *data;
 119        size_t size;
 120        int rv;
 121
 122        size = nla_total_size(sizeof(struct dlm_lock_data)) +
 123               nla_total_size(0); /* why this? */
 124
 125        rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
 126        if (rv < 0)
 127                return;
 128
 129        data = mk_data(send_skb);
 130        if (!data) {
 131                nlmsg_free(send_skb);
 132                return;
 133        }
 134
 135        fill_data(data, lkb);
 136
 137        send_data(send_skb);
 138}
 139
 140