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