diff options
Diffstat (limited to 'net/tipc/monitor.c')
| -rw-r--r-- | net/tipc/monitor.c | 803 |
1 files changed, 803 insertions, 0 deletions
diff --git a/net/tipc/monitor.c b/net/tipc/monitor.c new file mode 100644 index 000000000000..be70a57c1ff9 --- /dev/null +++ b/net/tipc/monitor.c @@ -0,0 +1,803 @@ +/* + * net/tipc/monitor.c + * + * Copyright (c) 2016, Ericsson AB + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the names of the copyright holders nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * Alternatively, this software may be distributed under the terms of the + * GNU General Public License ("GPL") version 2 as published by the Free + * Software Foundation. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include <net/genetlink.h> +#include "core.h" +#include "addr.h" +#include "monitor.h" +#include "bearer.h" + +#define MAX_MON_DOMAIN 64 +#define MON_TIMEOUT 120000 +#define MAX_PEER_DOWN_EVENTS 4 + +/* struct tipc_mon_domain: domain record to be transferred between peers + * @len: actual size of domain record + * @gen: current generation of sender's domain + * @ack_gen: most recent generation of self's domain acked by peer + * @member_cnt: number of domain member nodes described in this record + * @up_map: bit map indicating which of the members the sender considers up + * @members: identity of the domain members + */ +struct tipc_mon_domain { + u16 len; + u16 gen; + u16 ack_gen; + u16 member_cnt; + u64 up_map; + u32 members[MAX_MON_DOMAIN]; +}; + +/* struct tipc_peer: state of a peer node and its domain + * @addr: tipc node identity of peer + * @head_map: shows which other nodes currently consider peer 'up' + * @domain: most recent domain record from peer + * @hash: position in hashed lookup list + * @list: position in linked list, in circular ascending order by 'addr' + * @applied: number of reported domain members applied on this monitor list + * @is_up: peer is up as seen from this node + * @is_head: peer is assigned domain head as seen from this node + * @is_local: peer is in local domain and should be continuously monitored + * @down_cnt: - numbers of other peers which have reported this on lost + */ +struct tipc_peer { + u32 addr; + struct tipc_mon_domain *domain; + struct hlist_node hash; + struct list_head list; + u8 applied; + u8 down_cnt; + bool is_up; + bool is_head; + bool is_local; +}; + +struct tipc_monitor { + struct hlist_head peers[NODE_HTABLE_SIZE]; + int peer_cnt; + struct tipc_peer *self; + rwlock_t lock; + struct tipc_mon_domain cache; + u16 list_gen; + u16 dom_gen; + struct net *net; + struct timer_list timer; + unsigned long timer_intv; +}; + +static struct tipc_monitor *tipc_monitor(struct net *net, int bearer_id) +{ + return tipc_net(net)->monitors[bearer_id]; +} + +const int tipc_max_domain_size = sizeof(struct tipc_mon_domain); + +/* dom_rec_len(): actual length of domain record for transport + */ +static int dom_rec_len(struct tipc_mon_domain *dom, u16 mcnt) +{ + return ((void *)&dom->members - (void *)dom) + (mcnt * sizeof(u32)); +} + +/* dom_size() : calculate size of own domain based on number of peers + */ +static int dom_size(int peers) +{ + int i = 0; + + while ((i * i) < peers) + i++; + return i < MAX_MON_DOMAIN ? i : MAX_MON_DOMAIN; +} + +static void map_set(u64 *up_map, int i, unsigned int v) +{ + *up_map &= ~(1ULL << i); + *up_map |= ((u64)v << i); +} + +static int map_get(u64 up_map, int i) +{ + return (up_map & (1 << i)) >> i; +} + +static struct tipc_peer *peer_prev(struct tipc_peer *peer) +{ + return list_last_entry(&peer->list, struct tipc_peer, list); +} + +static struct tipc_peer *peer_nxt(struct tipc_peer *peer) +{ + return list_first_entry(&peer->list, struct tipc_peer, list); +} + +static struct tipc_peer *peer_head(struct tipc_peer *peer) +{ + while (!peer->is_head) + peer = peer_prev(peer); + return peer; +} + +static struct tipc_peer *get_peer(struct tipc_monitor *mon, u32 addr) +{ + struct tipc_peer *peer; + unsigned int thash = tipc_hashfn(addr); + + hlist_for_each_entry(peer, &mon->peers[thash], hash) { + if (peer->addr == addr) + return peer; + } + return NULL; +} + +static struct tipc_peer *get_self(struct net *net, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + + return mon->self; +} + +static inline bool tipc_mon_is_active(struct net *net, struct tipc_monitor *mon) +{ + struct tipc_net *tn = tipc_net(net); + + return mon->peer_cnt > tn->mon_threshold; +} + +/* mon_identify_lost_members() : - identify amd mark potentially lost members + */ +static void mon_identify_lost_members(struct tipc_peer *peer, + struct tipc_mon_domain *dom_bef, + int applied_bef) +{ + struct tipc_peer *member = peer; + struct tipc_mon_domain *dom_aft = peer->domain; + int applied_aft = peer->applied; + int i; + + for (i = 0; i < applied_bef; i++) { + member = peer_nxt(member); + + /* Do nothing if self or peer already see member as down */ + if (!member->is_up || !map_get(dom_bef->up_map, i)) + continue; + + /* Loss of local node must be detected by active probing */ + if (member->is_local) + continue; + + /* Start probing if member was removed from applied domain */ + if (!applied_aft || (applied_aft < i)) { + member->down_cnt = 1; + continue; + } + + /* Member loss is confirmed if it is still in applied domain */ + if (!map_get(dom_aft->up_map, i)) + member->down_cnt++; + } +} + +/* mon_apply_domain() : match a peer's domain record against monitor list + */ +static void mon_apply_domain(struct tipc_monitor *mon, + struct tipc_peer *peer) +{ + struct tipc_mon_domain *dom = peer->domain; + struct tipc_peer *member; + u32 addr; + int i; + + if (!dom || !peer->is_up) + return; + + /* Scan across domain members and match against monitor list */ + peer->applied = 0; + member = peer_nxt(peer); + for (i = 0; i < dom->member_cnt; i++) { + addr = dom->members[i]; + if (addr != member->addr) + return; + peer->applied++; + member = peer_nxt(member); + } +} + +/* mon_update_local_domain() : update after peer addition/removal/up/down + */ +static void mon_update_local_domain(struct tipc_monitor *mon) +{ + struct tipc_peer *self = mon->self; + struct tipc_mon_domain *cache = &mon->cache; + struct tipc_mon_domain *dom = self->domain; + struct tipc_peer *peer = self; + u64 prev_up_map = dom->up_map; + u16 member_cnt, i; + bool diff; + + /* Update local domain size based on current size of cluster */ + member_cnt = dom_size(mon->peer_cnt) - 1; + self->applied = member_cnt; + + /* Update native and cached outgoing local domain records */ + dom->len = dom_rec_len(dom, member_cnt); + diff = dom->member_cnt != member_cnt; + dom->member_cnt = member_cnt; + for (i = 0; i < member_cnt; i++) { + peer = peer_nxt(peer); + diff |= dom->members[i] != peer->addr; + dom->members[i] = peer->addr; + map_set(&dom->up_map, i, peer->is_up); + cache->members[i] = htonl(peer->addr); + } + diff |= dom->up_map != prev_up_map; + if (!diff) + return; + dom->gen = ++mon->dom_gen; + cache->len = htons(dom->len); + cache->gen = htons(dom->gen); + cache->member_cnt = htons(member_cnt); + cache->up_map = cpu_to_be64(dom->up_map); + mon_apply_domain(mon, self); +} + +/* mon_update_neighbors() : update preceding neighbors of added/removed peer + */ +static void mon_update_neighbors(struct tipc_monitor *mon, + struct tipc_peer *peer) +{ + int dz, i; + + dz = dom_size(mon->peer_cnt); + for (i = 0; i < dz; i++) { + mon_apply_domain(mon, peer); + peer = peer_prev(peer); + } +} + +/* mon_assign_roles() : reassign peer roles after a network change + * The monitor list is consistent at this stage; i.e., each peer is monitoring + * a set of domain members as matched between domain record and the monitor list + */ +static void mon_assign_roles(struct tipc_monitor *mon, struct tipc_peer *head) +{ + struct tipc_peer *peer = peer_nxt(head); + struct tipc_peer *self = mon->self; + int i = 0; + + for (; peer != self; peer = peer_nxt(peer)) { + peer->is_local = false; + + /* Update domain member */ + if (i++ < head->applied) { + peer->is_head = false; + if (head == self) + peer->is_local = true; + continue; + } + /* Assign next domain head */ + if (!peer->is_up) + continue; + if (peer->is_head) + break; + head = peer; + head->is_head = true; + i = 0; + } + mon->list_gen++; +} + +void tipc_mon_remove_peer(struct net *net, u32 addr, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *self = get_self(net, bearer_id); + struct tipc_peer *peer, *prev, *head; + + write_lock_bh(&mon->lock); + peer = get_peer(mon, addr); + if (!peer) + goto exit; + prev = peer_prev(peer); + list_del(&peer->list); + hlist_del(&peer->hash); + kfree(peer->domain); + kfree(peer); + mon->peer_cnt--; + head = peer_head(prev); + if (head == self) + mon_update_local_domain(mon); + mon_update_neighbors(mon, prev); + + /* Revert to full-mesh monitoring if we reach threshold */ + if (!tipc_mon_is_active(net, mon)) { + list_for_each_entry(peer, &self->list, list) { + kfree(peer->domain); + peer->domain = NULL; + peer->applied = 0; + } + } + mon_assign_roles(mon, head); +exit: + write_unlock_bh(&mon->lock); +} + +static bool tipc_mon_add_peer(struct tipc_monitor *mon, u32 addr, + struct tipc_peer **peer) +{ + struct tipc_peer *self = mon->self; + struct tipc_peer *cur, *prev, *p; + + p = kzalloc(sizeof(*p), GFP_ATOMIC); + *peer = p; + if (!p) + return false; + p->addr = addr; + + /* Add new peer to lookup list */ + INIT_LIST_HEAD(&p->list); + hlist_add_head(&p->hash, &mon->peers[tipc_hashfn(addr)]); + + /* Sort new peer into iterator list, in ascending circular order */ + prev = self; + list_for_each_entry(cur, &self->list, list) { + if ((addr > prev->addr) && (addr < cur->addr)) + break; + if (((addr < cur->addr) || (addr > prev->addr)) && + (prev->addr > cur->addr)) + break; + prev = cur; + } + list_add_tail(&p->list, &cur->list); + mon->peer_cnt++; + mon_update_neighbors(mon, p); + return true; +} + +void tipc_mon_peer_up(struct net *net, u32 addr, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *self = get_self(net, bearer_id); + struct tipc_peer *peer, *head; + + write_lock_bh(&mon->lock); + peer = get_peer(mon, addr); + if (!peer && !tipc_mon_add_peer(mon, addr, &peer)) + goto exit; + peer->is_up = true; + head = peer_head(peer); + if (head == self) + mon_update_local_domain(mon); + mon_assign_roles(mon, head); +exit: + write_unlock_bh(&mon->lock); +} + +void tipc_mon_peer_down(struct net *net, u32 addr, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *self = get_self(net, bearer_id); + struct tipc_peer *peer, *head; + struct tipc_mon_domain *dom; + int applied; + + write_lock_bh(&mon->lock); + peer = get_peer(mon, addr); + if (!peer) { + pr_warn("Mon: unknown link %x/%u DOWN\n", addr, bearer_id); + goto exit; + } + applied = peer->applied; + peer->applied = 0; + dom = peer->domain; + peer->domain = NULL; + if (peer->is_head) + mon_identify_lost_members(peer, dom, applied); + kfree(dom); + peer->is_up = false; + peer->is_head = false; + peer->is_local = false; + peer->down_cnt = 0; + head = peer_head(peer); + if (head == self) + mon_update_local_domain(mon); + mon_assign_roles(mon, head); +exit: + write_unlock_bh(&mon->lock); +} + +/* tipc_mon_rcv - process monitor domain event message + */ +void tipc_mon_rcv(struct net *net, void *data, u16 dlen, u32 addr, + struct tipc_mon_state *state, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_mon_domain *arrv_dom = data; + struct tipc_mon_domain dom_bef; + struct tipc_mon_domain *dom; + struct tipc_peer *peer; + u16 new_member_cnt = ntohs(arrv_dom->member_cnt); + int new_dlen = dom_rec_len(arrv_dom, new_member_cnt); + u16 new_gen = ntohs(arrv_dom->gen); + u16 acked_gen = ntohs(arrv_dom->ack_gen); + bool probing = state->probing; + int i, applied_bef; + + state->probing = false; + if (!dlen) + return; + + /* Sanity check received domain record */ + if ((dlen < new_dlen) || ntohs(arrv_dom->len) != new_dlen) { + pr_warn_ratelimited("Received illegal domain record\n"); + return; + } + + /* Synch generation numbers with peer if link just came up */ + if (!state->synched) { + state->peer_gen = new_gen - 1; + state->acked_gen = acked_gen; + state->synched = true; + } + + if (more(acked_gen, state->acked_gen)) + state->acked_gen = acked_gen; + + /* Drop duplicate unless we are waiting for a probe response */ + if (!more(new_gen, state->peer_gen) && !probing) + return; + + write_lock_bh(&mon->lock); + peer = get_peer(mon, addr); + if (!peer || !peer->is_up) + goto exit; + + /* Peer is confirmed, stop any ongoing probing */ + peer->down_cnt = 0; + + /* Task is done for duplicate record */ + if (!more(new_gen, state->peer_gen)) + goto exit; + + state->peer_gen = new_gen; + + /* Cache current domain record for later use */ + dom_bef.member_cnt = 0; + dom = peer->domain; + if (dom) + memcpy(&dom_bef, dom, dom->len); + + /* Transform and store received domain record */ + if (!dom || (dom->len < new_dlen)) { + kfree(dom); + dom = kmalloc(new_dlen, GFP_ATOMIC); + peer->domain = dom; + if (!dom) + goto exit; + } + dom->len = new_dlen; + dom->gen = new_gen; + dom->member_cnt = new_member_cnt; + dom->up_map = be64_to_cpu(arrv_dom->up_map); + for (i = 0; i < new_member_cnt; i++) + dom->members[i] = ntohl(arrv_dom->members[i]); + + /* Update peers affected by this domain record */ + applied_bef = peer->applied; + mon_apply_domain(mon, peer); + mon_identify_lost_members(peer, &dom_bef, applied_bef); + mon_assign_roles(mon, peer_head(peer)); +exit: + write_unlock_bh(&mon->lock); +} + +void tipc_mon_prep(struct net *net, void *data, int *dlen, + struct tipc_mon_state *state, int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_mon_domain *dom = data; + u16 gen = mon->dom_gen; + u16 len; + + if (!tipc_mon_is_active(net, mon)) + return; + + /* Send only a dummy record with ack if peer has acked our last sent */ + if (likely(state->acked_gen == gen)) { + len = dom_rec_len(dom, 0); + *dlen = len; + dom->len = htons(len); + dom->gen = htons(gen); + dom->ack_gen = htons(state->peer_gen); + dom->member_cnt = 0; + return; + } + /* Send the full record */ + read_lock_bh(&mon->lock); + len = ntohs(mon->cache.len); + *dlen = len; + memcpy(data, &mon->cache, len); + read_unlock_bh(&mon->lock); + dom->ack_gen = htons(state->peer_gen); +} + +void tipc_mon_get_state(struct net *net, u32 addr, + struct tipc_mon_state *state, + int bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *peer; + + /* Used cached state if table has not changed */ + if (!state->probing && + (state->list_gen == mon->list_gen) && + (state->acked_gen == mon->dom_gen)) + return; + + read_lock_bh(&mon->lock); + peer = get_peer(mon, addr); + if (peer) { + state->probing = state->acked_gen != mon->dom_gen; + state->probing |= peer->down_cnt; + state->reset |= peer->down_cnt >= MAX_PEER_DOWN_EVENTS; + state->monitoring = peer->is_local; + state->monitoring |= peer->is_head; + state->list_gen = mon->list_gen; + } + read_unlock_bh(&mon->lock); +} + +static void mon_timeout(unsigned long m) +{ + struct tipc_monitor *mon = (void *)m; + struct tipc_peer *self; + int best_member_cnt = dom_size(mon->peer_cnt) - 1; + + write_lock_bh(&mon->lock); + self = mon->self; + if (self && (best_member_cnt != self->applied)) { + mon_update_local_domain(mon); + mon_assign_roles(mon, self); + } + write_unlock_bh(&mon->lock); + mod_timer(&mon->timer, jiffies + mon->timer_intv); +} + +int tipc_mon_create(struct net *net, int bearer_id) +{ + struct tipc_net *tn = tipc_net(net); + struct tipc_monitor *mon; + struct tipc_peer *self; + struct tipc_mon_domain *dom; + + if (tn->monitors[bearer_id]) + return 0; + + mon = kzalloc(sizeof(*mon), GFP_ATOMIC); + self = kzalloc(sizeof(*self), GFP_ATOMIC); + dom = kzalloc(sizeof(*dom), GFP_ATOMIC); + if (!mon || !self || !dom) { + kfree(mon); + kfree(self); + kfree(dom); + return -ENOMEM; + } + tn->monitors[bearer_id] = mon; + rwlock_init(&mon->lock); + mon->net = net; + mon->peer_cnt = 1; + mon->self = self; + self->domain = dom; + self->addr = tipc_own_addr(net); + self->is_up = true; + self->is_head = true; + INIT_LIST_HEAD(&self->list); + setup_timer(&mon->timer, mon_timeout, (unsigned long)mon); + mon->timer_intv = msecs_to_jiffies(MON_TIMEOUT + (tn->random & 0xffff)); + mod_timer(&mon->timer, jiffies + mon->timer_intv); + return 0; +} + +void tipc_mon_delete(struct net *net, int bearer_id) +{ + struct tipc_net *tn = tipc_net(net); + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *self = get_self(net, bearer_id); + struct tipc_peer *peer, *tmp; + + write_lock_bh(&mon->lock); + tn->monitors[bearer_id] = NULL; + list_for_each_entry_safe(peer, tmp, &self->list, list) { + list_del(&peer->list); + hlist_del(&peer->hash); + kfree(peer->domain); + kfree(peer); + } + mon->self = NULL; + write_unlock_bh(&mon->lock); + del_timer_sync(&mon->timer); + kfree(self->domain); + kfree(self); + kfree(mon); +} + +int tipc_nl_monitor_set_threshold(struct net *net, u32 cluster_size) +{ + struct tipc_net *tn = tipc_net(net); + + if (cluster_size > TIPC_CLUSTER_SIZE) + return -EINVAL; + + tn->mon_threshold = cluster_size; + + return 0; +} + +int tipc_nl_monitor_get_threshold(struct net *net) +{ + struct tipc_net *tn = tipc_net(net); + + return tn->mon_threshold; +} + +int __tipc_nl_add_monitor_peer(struct tipc_peer *peer, struct tipc_nl_msg *msg) +{ + struct tipc_mon_domain *dom = peer->domain; + struct nlattr *attrs; + void *hdr; + + hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, + NLM_F_MULTI, TIPC_NL_MON_PEER_GET); + if (!hdr) + return -EMSGSIZE; + + attrs = nla_nest_start(msg->skb, TIPC_NLA_MON_PEER); + if (!attrs) + goto msg_full; + + if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_ADDR, peer->addr)) + goto attr_msg_full; + if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_APPLIED, peer->applied)) + goto attr_msg_full; + + if (peer->is_up) + if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_UP)) + goto attr_msg_full; + if (peer->is_local) + if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_LOCAL)) + goto attr_msg_full; + if (peer->is_head) + if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_HEAD)) + goto attr_msg_full; + + if (dom) { + if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_DOMGEN, dom->gen)) + goto attr_msg_full; + if (nla_put_u64_64bit(msg->skb, TIPC_NLA_MON_PEER_UPMAP, + dom->up_map, TIPC_NLA_MON_PEER_PAD)) + goto attr_msg_full; + if (nla_put(msg->skb, TIPC_NLA_MON_PEER_MEMBERS, + dom->member_cnt * sizeof(u32), &dom->members)) + goto attr_msg_full; + } + + nla_nest_end(msg->skb, attrs); + genlmsg_end(msg->skb, hdr); + return 0; + +attr_msg_full: + nla_nest_cancel(msg->skb, attrs); +msg_full: + genlmsg_cancel(msg->skb, hdr); + + return -EMSGSIZE; +} + +int tipc_nl_add_monitor_peer(struct net *net, struct tipc_nl_msg *msg, + u32 bearer_id, u32 *prev_node) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + struct tipc_peer *peer = mon->self; + + if (!mon) + return -EINVAL; + + read_lock_bh(&mon->lock); + do { + if (*prev_node) { + if (peer->addr == *prev_node) + *prev_node = 0; + else + continue; + } + if (__tipc_nl_add_monitor_peer(peer, msg)) { + *prev_node = peer->addr; + read_unlock_bh(&mon->lock); + return -EMSGSIZE; + } + } while ((peer = peer_nxt(peer)) != mon->self); + read_unlock_bh(&mon->lock); + + return 0; +} + +int __tipc_nl_add_monitor(struct net *net, struct tipc_nl_msg *msg, + u32 bearer_id) +{ + struct tipc_monitor *mon = tipc_monitor(net, bearer_id); + char bearer_name[TIPC_MAX_BEARER_NAME]; + struct nlattr *attrs; + void *hdr; + int ret; + + ret = tipc_bearer_get_name(net, bearer_name, bearer_id); + if (ret || !mon) + return -EINVAL; + + hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, + NLM_F_MULTI, TIPC_NL_MON_GET); + if (!hdr) + return -EMSGSIZE; + + attrs = nla_nest_start(msg->skb, TIPC_NLA_MON); + if (!attrs) + goto msg_full; + + read_lock_bh(&mon->lock); + if (nla_put_u32(msg->skb, TIPC_NLA_MON_REF, bearer_id)) + goto attr_msg_full; + if (tipc_mon_is_active(net, mon)) + if (nla_put_flag(msg->skb, TIPC_NLA_MON_ACTIVE)) + goto attr_msg_full; + if (nla_put_string(msg->skb, TIPC_NLA_MON_BEARER_NAME, bearer_name)) + goto attr_msg_full; + if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEERCNT, mon->peer_cnt)) + goto attr_msg_full; + if (nla_put_u32(msg->skb, TIPC_NLA_MON_LISTGEN, mon->list_gen)) + goto attr_msg_full; + + read_unlock_bh(&mon->lock); + nla_nest_end(msg->skb, attrs); + genlmsg_end(msg->skb, hdr); + + return 0; + +attr_msg_full: + nla_nest_cancel(msg->skb, attrs); +msg_full: + genlmsg_cancel(msg->skb, hdr); + read_unlock_bh(&mon->lock); + + return -EMSGSIZE; +} |