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_nlportid;
  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
  60        genlmsg_end(skb, data);
  61
  62        return genlmsg_unicast(&init_net, skb, listener_nlportid);
  63}
  64
  65static int user_cmd(struct sk_buff *skb, struct genl_info *info)
  66{
  67        listener_nlportid = info->snd_portid;
  68        printk("user_cmd nlpid %u\n", listener_nlportid);
  69        return 0;
  70}
  71
  72static struct genl_ops dlm_nl_ops[] = {
  73        {
  74                .cmd    = DLM_CMD_HELLO,
  75                .doit   = user_cmd,
  76        },
  77};
  78
  79int __init dlm_netlink_init(void)
  80{
  81        return genl_register_family_with_ops(&family, dlm_nl_ops);
  82}
  83
  84void dlm_netlink_exit(void)
  85{
  86        genl_unregister_family(&family);
  87}
  88
  89static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
  90{
  91        struct dlm_rsb *r = lkb->lkb_resource;
  92
  93        memset(data, 0, sizeof(struct dlm_lock_data));
  94
  95        data->version = DLM_LOCK_DATA_VERSION;
  96        data->nodeid = lkb->lkb_nodeid;
  97        data->ownpid = lkb->lkb_ownpid;
  98        data->id = lkb->lkb_id;
  99        data->remid = lkb->lkb_remid;
 100        data->status = lkb->lkb_status;
 101        data->grmode = lkb->lkb_grmode;
 102        data->rqmode = lkb->lkb_rqmode;
 103        if (lkb->lkb_ua)
 104                data->xid = lkb->lkb_ua->xid;
 105        if (r) {
 106                data->lockspace_id = r->res_ls->ls_global_id;
 107                data->resource_namelen = r->res_length;
 108                memcpy(data->resource_name, r->res_name, r->res_length);
 109        }
 110}
 111
 112void dlm_timeout_warn(struct dlm_lkb *lkb)
 113{
 114        struct sk_buff *uninitialized_var(send_skb);
 115        struct dlm_lock_data *data;
 116        size_t size;
 117        int rv;
 118
 119        size = nla_total_size(sizeof(struct dlm_lock_data)) +
 120               nla_total_size(0); /* why this? */
 121
 122        rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
 123        if (rv < 0)
 124                return;
 125
 126        data = mk_data(send_skb);
 127        if (!data) {
 128                nlmsg_free(send_skb);
 129                return;
 130        }
 131
 132        fill_data(data, lkb);
 133
 134        send_data(send_skb);
 135}
 136
 137