LXR linux/fs/dlm/netlink.c

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) 2007 Red Hat, Inc.  All rights reserved.
   4 */
   5
   6#include <net/genetlink.h>
   7#include <linux/dlm.h>
   8#include <linux/dlm_netlink.h>
   9#include <linux/gfp.h>
  10
  11#include "dlm_internal.h"
  12
  13static uint32_t dlm_nl_seqnum;
  14static uint32_t listener_nlportid;
  15
  16static struct genl_family family;
  17
  18static int prepare_data(u8 cmd, struct sk_buff **skbp, size_t size)
  19{
  20        struct sk_buff *skb;
  21        void *data;
  22
  23        skb = genlmsg_new(size, GFP_NOFS);
  24        if (!skb)
  25                return -ENOMEM;
  26
  27        /* add the message headers */
  28        data = genlmsg_put(skb, 0, dlm_nl_seqnum++, &family, 0, cmd);
  29        if (!data) {
  30                nlmsg_free(skb);
  31                return -EINVAL;
  32        }
  33
  34        *skbp = skb;
  35        return 0;
  36}
  37
  38static struct dlm_lock_data *mk_data(struct sk_buff *skb)
  39{
  40        struct nlattr *ret;
  41
  42        ret = nla_reserve(skb, DLM_TYPE_LOCK, sizeof(struct dlm_lock_data));
  43        if (!ret)
  44                return NULL;
  45        return nla_data(ret);
  46}
  47
  48static int send_data(struct sk_buff *skb)
  49{
  50        struct genlmsghdr *genlhdr = nlmsg_data((struct nlmsghdr *)skb->data);
  51        void *data = genlmsg_data(genlhdr);
  52
  53        genlmsg_end(skb, data);
  54
  55        return genlmsg_unicast(&init_net, skb, listener_nlportid);
  56}
  57
  58static int user_cmd(struct sk_buff *skb, struct genl_info *info)
  59{
  60        listener_nlportid = info->snd_portid;
  61        printk("user_cmd nlpid %u\n", listener_nlportid);
  62        return 0;
  63}
  64
  65static const struct genl_small_ops dlm_nl_ops[] = {
  66        {
  67                .cmd    = DLM_CMD_HELLO,
  68                .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
  69                .doit   = user_cmd,
  70        },
  71};
  72
  73static struct genl_family family __ro_after_init = {
  74        .name           = DLM_GENL_NAME,
  75        .version        = DLM_GENL_VERSION,
  76        .small_ops      = dlm_nl_ops,
  77        .n_small_ops    = ARRAY_SIZE(dlm_nl_ops),
  78        .module         = THIS_MODULE,
  79};
  80
  81int __init dlm_netlink_init(void)
  82{
  83        return genl_register_family(&family);
  84}
  85
  86void dlm_netlink_exit(void)
  87{
  88        genl_unregister_family(&family);
  89}
  90
  91static void fill_data(struct dlm_lock_data *data, struct dlm_lkb *lkb)
  92{
  93        struct dlm_rsb *r = lkb->lkb_resource;
  94
  95        memset(data, 0, sizeof(struct dlm_lock_data));
  96
  97        data->version = DLM_LOCK_DATA_VERSION;
  98        data->nodeid = lkb->lkb_nodeid;
  99        data->ownpid = lkb->lkb_ownpid;
 100        data->id = lkb->lkb_id;
 101        data->remid = lkb->lkb_remid;
 102        data->status = lkb->lkb_status;
 103        data->grmode = lkb->lkb_grmode;
 104        data->rqmode = lkb->lkb_rqmode;
 105        if (lkb->lkb_ua)
 106                data->xid = lkb->lkb_ua->xid;
 107        if (r) {
 108                data->lockspace_id = r->res_ls->ls_global_id;
 109                data->resource_namelen = r->res_length;
 110                memcpy(data->resource_name, r->res_name, r->res_length);
 111        }
 112}
 113
 114void dlm_timeout_warn(struct dlm_lkb *lkb)
 115{
 116        struct sk_buff *send_skb;
 117        struct dlm_lock_data *data;
 118        size_t size;
 119        int rv;
 120
 121        size = nla_total_size(sizeof(struct dlm_lock_data)) +
 122               nla_total_size(0); /* why this? */
 123
 124        rv = prepare_data(DLM_CMD_TIMEOUT, &send_skb, size);
 125        if (rv < 0)
 126                return;
 127
 128        data = mk_data(send_skb);
 129        if (!data) {
 130                nlmsg_free(send_skb);
 131                return;
 132        }
 133
 134        fill_data(data, lkb);
 135
 136        send_data(send_skb);
 137}
 138
 139