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
  13#include "dlm_internal.h"
  14
  15static uint32_t dlm_nl_seqnum;
  16static uint32_t listener_nlpid;
  17
  18static struct genl_family family = {
  19        .id             = GENL_ID_GENERATE,
  20        .name           = DLM_GENL_NAME,
  21        .version        = DLM_GENL_VERSION,
  22};
  23
  24static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
  25{
  26        struct sk_buff *skb;
  27        void *data;
  28
  29        skb = genlmsg_new(size, GFP_KERNEL);
  30        if (!skb)
  31                return -ENOMEM;
  32
  33        /* add the message headers */
  34        data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
  35        if (!data) {
  36                nlmsg_free(skb);
  37                return -EINVAL;
  38        }
  39
  40        *skbp = skb;
  41        return 0;
  42}
  43
  44static struct dlm_lock_data *mk_data(struct sk_buff *skb)
  45{
  46        struct nlattr *ret;
  47
  48        ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
  49        if (!ret)
  50                return NULL;
  51        return nla_data(ret);
  52}
  53
  54static int send_data(struct sk_buff *skb)
  55{
  56        struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
  57        void *data = genlmsg_data(genlhdr);
  58        int rv;
  59
  60        rv = genlmsg_end(skb, data);
  61        if (rv < 0) {
  62                nlmsg_free(skb);
  63                return rv;
  64        }
  65
  66        return genlmsg_unicast(&init_net, skb, listener_nlpid);
  67}
  68
  69static int user_cmd(struct sk_buff *skb, struct genl_info *info)
  70{
  71        listener_nlpid = info->snd_pid;
  72        printk("user_cmd nlpid %u\n", listener_nlpid);
  73        return 0;
  74}
  75
  76static struct genl_ops dlm_nl_ops = {
  77        .cmd            = DLM_CMD_HELLO,
  78        .doit           = user_cmd,
  79};
  80
  81int __init dlm_netlink_init(void)
  82{
  83        int rv;
  84
  85        rv = genl_register_family(&family);
  86        if (rv)
  87                return rv;
  88
  89        rv = genl_register_ops(&family, &dlm_nl_ops);
  90        if (rv < 0)
  91                goto err;
  92        return 0;
  93 err:
  94        genl_unregister_family(&family);
  95        return rv;
  96}
  97
  98void dlm_netlink_exit(void)
  99{
 100        genl_unregister_ops(&family, &dlm_nl_ops);
 101        genl_unregister_family(&family);
 102}
 103
 104static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
 105{
 106        struct dlm_rsb *r = lkb->lkb_resource;
 107
 108        memset(data, 0, sizeof(struct dlm_lock_data));
 109
 110        data->version = DLM_LOCK_DATA_VERSION;
 111        data->nodeid = lkb->lkb_nodeid;
 112        data->ownpid = lkb->lkb_ownpid;
 113        data->id = lkb->lkb_id;
 114        data->remid = lkb->lkb_remid;
 115        data->status = lkb->lkb_status;
 116        data->grmode = lkb->lkb_grmode;
 117        data->rqmode = lkb->lkb_rqmode;
 118        if (lkb->lkb_ua)
 119                data->xid = lkb->lkb_ua->xid;
 120        if (r) {
 121                data->lockspace_id = r->res_ls->ls_global_id;
 122                data->resource_namelen = r->res_length;
 123                memcpy(data->resource_name, r->res_name, r->res_length);
 124        }
 125}
 126
 127void dlm_timeout_warn(struct dlm_lkb *lkb)
 128{
 129        struct sk_buff *uninitialized_var(send_skb);
 130        struct dlm_lock_data *data;
 131        size_t size;
 132        int rv;
 133
 134        size = nla_total_size(sizeof(struct dlm_lock_data)) +
 135               nla_total_size(0); /* why this? */
 136
 137        rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
 138        if (rv < 0)
 139                return;
 140
 141        data = mk_data(send_skb);
 142        if (!data) {
 143                nlmsg_free(send_skb);
 144                return;
 145        }
 146
 147        fill_data(data, lkb);
 148
 149        send_data(send_skb);
 150}
 151
 152