1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191 | // Copyright (C) 2020-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#include <config.h>
#include <dhcp6/client_handler.h>
#include <dhcp6/dhcp6_log.h>
#include <exceptions/exceptions.h>
#include <stats/stats_mgr.h>
#include <util/multi_threading_mgr.h>
using namespace std;
using namespace isc::util;
using namespace isc::log;
namespace isc {
namespace dhcp {
ClientHandler::Client::Client(Pkt6Ptr query, DuidPtr client_id)
: query_(query), thread_(this_thread::get_id()) {
// Sanity checks.
if (!query) {
isc_throw(InvalidParameter, "null query in ClientHandler");
}
if (!client_id) {
isc_throw(InvalidParameter, "null client-id in ClientHandler");
}
duid_ = client_id->getDuid();
}
mutex ClientHandler::mutex_;
ClientHandler::ClientContainer ClientHandler::clients_;
ClientHandler::ClientPtr
ClientHandler::lookup(const DuidPtr& duid) {
// Sanity check.
if (!duid) {
isc_throw(InvalidParameter, "null duid in ClientHandler::lookup");
}
auto it = clients_.find(duid->getDuid());
if (it == clients_.end()) {
return (ClientPtr());
}
return (*it);
}
void
ClientHandler::add(const ClientPtr& client) {
// Sanity check.
if (!client) {
isc_throw(InvalidParameter, "null client in ClientHandler::add");
}
// Assume insert will never fail so not checking its result.
clients_.insert(client);
}
void
ClientHandler::del(const DuidPtr& duid) {
// Sanity check.
if (!duid) {
isc_throw(InvalidParameter, "null duid in ClientHandler::del");
}
// Assume erase will never fail so not checking its result.
clients_.erase(duid->getDuid());
}
ClientHandler::ClientHandler() : client_(), locked_() {
}
ClientHandler::~ClientHandler() {
if (locked_) {
lock_guard<mutex> lk(mutex_);
unLock();<--- Exception thrown in function declared not to throw exceptions.
}
}
bool
ClientHandler::tryLock(Pkt6Ptr query, ContinuationPtr cont) {
// Sanity checks.
if (!query) {
isc_throw(InvalidParameter, "null query in ClientHandler::tryLock");
}
if (locked_) {
isc_throw(Unexpected, "already handling in ClientHandler::tryLock");
}
const DuidPtr& duid = query->getClientId();
if (!duid) {
// Can't do something useful: cross fingers.
return (true);
}
if (duid->getDuid().empty()) {
// A lot of code assumes this will never happen...
isc_throw(Unexpected, "empty DUID in ClientHandler::tryLock");
}
ClientPtr holder;
Pkt6Ptr next_query;
client_.reset(new Client(query, duid));
{
// Try to acquire the lock and return the holder when it failed.
lock_guard<mutex> lk(mutex_);
holder = lookup(duid);
if (!holder) {
locked_ = duid;
lock();
return (true);
}
// This query can be a duplicate so put the continuation.
if (cont) {
next_query = holder->next_query_;
holder->next_query_ = query;
holder->cont_ = cont;
}
}
if (cont) {
if (next_query) {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet6_logger, DBGLVL_PKT_HANDLING, DHCP6_PACKET_DROP_DUPLICATE)
.arg(next_query->makeLabel(next_query->getClientId(), nullptr))
.arg(next_query->toText())
.arg(this_thread::get_id())
.arg(holder->query_->makeLabel(holder->query_->getClientId(), nullptr))
.arg(holder->query_->toText())
.arg(holder->thread_);
stats::StatsMgr::instance().addValue("pkt6-receive-drop",
static_cast<int64_t>(1));
}
} else {
// Logging a warning as it is supposed to be a rare event
// with well behaving clients...
LOG_DEBUG(bad_packet6_logger, DBGLVL_PKT_HANDLING, DHCP6_PACKET_DROP_DUPLICATE)
.arg(query->makeLabel(query->getClientId(), nullptr))
.arg(query->toText())
.arg(this_thread::get_id())
.arg(holder->query_->makeLabel(holder->query_->getClientId(), nullptr))
.arg(holder->query_->toText())
.arg(holder->thread_);
stats::StatsMgr::instance().addValue("pkt6-receive-drop",
static_cast<int64_t>(1));
}
return (false);
}
void
ClientHandler::lock() {
// Sanity check.
if (!locked_) {
isc_throw(Unexpected, "nothing to lock in ClientHandler::lock");
}
add(client_);
}
void
ClientHandler::unLock() {
// Sanity check.
if (!locked_) {
isc_throw(Unexpected, "nothing to unlock in ClientHandler::unLock");
}
del(locked_);
locked_.reset();
if (!client_ || !client_->cont_) {
return;
}
// Try to process next query. As the caller holds the mutex of
// the handler class the continuation will be resumed after.
MultiThreadingMgr& mt_mgr = MultiThreadingMgr::instance();
if (mt_mgr.getMode()) {
if (!mt_mgr.getThreadPool().addFront(client_->cont_)) {
LOG_DEBUG(dhcp6_logger, DBG_DHCP6_BASIC, DHCP6_PACKET_QUEUE_FULL);
}
}
}
} // namespace dhcp
} // namespace isc
|