1 /*
2 Copyright (c) 2007-2019 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28 */
29
30 #include "precompiled.hpp"
31 #include "ws_protocol.hpp"
32 #include "ws_encoder.hpp"
33 #include "msg.hpp"
34 #include "likely.hpp"
35 #include "wire.hpp"
36 #include "random.hpp"
37
38 #include <limits.h>
39
ws_encoder_t(size_t bufsize_,bool must_mask_)40 zmq::ws_encoder_t::ws_encoder_t (size_t bufsize_, bool must_mask_) :
41 encoder_base_t<ws_encoder_t> (bufsize_),
42 _must_mask (must_mask_)
43 {
44 // Write 0 bytes to the batch and go to message_ready state.
45 next_step (NULL, 0, &ws_encoder_t::message_ready, true);
46 _masked_msg.init ();
47 }
48
~ws_encoder_t()49 zmq::ws_encoder_t::~ws_encoder_t ()
50 {
51 _masked_msg.close ();
52 }
53
message_ready()54 void zmq::ws_encoder_t::message_ready ()
55 {
56 int offset = 0;
57
58 _is_binary = false;
59
60 if (in_progress ()->is_ping ())
61 _tmp_buf[offset++] = 0x80 | zmq::ws_protocol_t::opcode_ping;
62 else if (in_progress ()->is_pong ())
63 _tmp_buf[offset++] = 0x80 | zmq::ws_protocol_t::opcode_pong;
64 else if (in_progress ()->is_close_cmd ())
65 _tmp_buf[offset++] = 0x80 | zmq::ws_protocol_t::opcode_close;
66 else {
67 _tmp_buf[offset++] = 0x82; // Final | binary
68 _is_binary = true;
69 }
70
71 _tmp_buf[offset] = _must_mask ? 0x80 : 0x00;
72
73 size_t size = in_progress ()->size ();
74 if (_is_binary)
75 size++;
76 // TODO: create an opcode for subscribe/cancel
77 if (in_progress ()->is_subscribe () || in_progress ()->is_cancel ())
78 size++;
79
80 if (size <= 125)
81 _tmp_buf[offset++] |= static_cast<unsigned char> (size & 127);
82 else if (size <= 0xFFFF) {
83 _tmp_buf[offset++] |= 126;
84 _tmp_buf[offset++] = static_cast<unsigned char> ((size >> 8) & 0xFF);
85 _tmp_buf[offset++] = static_cast<unsigned char> (size & 0xFF);
86 } else {
87 _tmp_buf[offset++] |= 127;
88 put_uint64 (_tmp_buf + offset, size);
89 offset += 8;
90 }
91
92 if (_must_mask) {
93 const uint32_t random = generate_random ();
94 put_uint32 (_tmp_buf + offset, random);
95 put_uint32 (_mask, random);
96 offset += 4;
97 }
98
99 int mask_index = 0;
100 if (_is_binary) {
101 // Encode flags.
102 unsigned char protocol_flags = 0;
103 if (in_progress ()->flags () & msg_t::more)
104 protocol_flags |= ws_protocol_t::more_flag;
105 if (in_progress ()->flags () & msg_t::command)
106 protocol_flags |= ws_protocol_t::command_flag;
107
108 _tmp_buf[offset++] =
109 _must_mask ? protocol_flags ^ _mask[mask_index++] : protocol_flags;
110 }
111
112 // Encode the subscribe/cancel byte.
113 // TODO: remove once there is an opcode for subscribe/cancel
114 if (in_progress ()->is_subscribe ())
115 _tmp_buf[offset++] = _must_mask ? 1 ^ _mask[mask_index++] : 1;
116 else if (in_progress ()->is_cancel ())
117 _tmp_buf[offset++] = _must_mask ? 0 ^ _mask[mask_index++] : 0;
118
119 next_step (_tmp_buf, offset, &ws_encoder_t::size_ready, false);
120 }
121
size_ready()122 void zmq::ws_encoder_t::size_ready ()
123 {
124 if (_must_mask) {
125 assert (in_progress () != &_masked_msg);
126 const size_t size = in_progress ()->size ();
127
128 unsigned char *src =
129 static_cast<unsigned char *> (in_progress ()->data ());
130 unsigned char *dest = src;
131
132 // If msg is shared or data is constant we cannot mask in-place, allocate a new msg for it
133 if (in_progress ()->flags () & msg_t::shared
134 || in_progress ()->is_cmsg ()) {
135 _masked_msg.close ();
136 _masked_msg.init_size (size);
137 dest = static_cast<unsigned char *> (_masked_msg.data ());
138 }
139
140 int mask_index = 0;
141 if (_is_binary)
142 ++mask_index;
143 // TODO: remove once there is an opcode for subscribe/cancel
144 if (in_progress ()->is_subscribe () || in_progress ()->is_cancel ())
145 ++mask_index;
146 for (size_t i = 0; i < size; ++i, mask_index++)
147 dest[i] = src[i] ^ _mask[mask_index % 4];
148
149 next_step (dest, size, &ws_encoder_t::message_ready, true);
150 } else {
151 next_step (in_progress ()->data (), in_progress ()->size (),
152 &ws_encoder_t::message_ready, true);
153 }
154 }
155