1 /* Copyright (c) 2014, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15 #include "packeted_bio.h"
16
17 #include <assert.h>
18 #include <limits.h>
19 #include <stdio.h>
20 #include <string.h>
21
22 #include <openssl/mem.h>
23
24
25 namespace {
26
27 extern const BIO_METHOD g_packeted_bio_method;
28
29 const uint8_t kOpcodePacket = 'P';
30 const uint8_t kOpcodeTimeout = 'T';
31 const uint8_t kOpcodeTimeoutAck = 't';
32
33 // ReadAll reads |len| bytes from |bio| into |out|. It returns 1 on success and
34 // 0 or -1 on error.
ReadAll(BIO * bio,uint8_t * out,size_t len)35 static int ReadAll(BIO *bio, uint8_t *out, size_t len) {
36 while (len > 0) {
37 int chunk_len = INT_MAX;
38 if (len <= INT_MAX) {
39 chunk_len = (int)len;
40 }
41 int ret = BIO_read(bio, out, chunk_len);
42 if (ret <= 0) {
43 return ret;
44 }
45 out += ret;
46 len -= ret;
47 }
48 return 1;
49 }
50
PacketedWrite(BIO * bio,const char * in,int inl)51 static int PacketedWrite(BIO *bio, const char *in, int inl) {
52 if (bio->next_bio == NULL) {
53 return 0;
54 }
55
56 BIO_clear_retry_flags(bio);
57
58 // Write the header.
59 uint8_t header[5];
60 header[0] = kOpcodePacket;
61 header[1] = (inl >> 24) & 0xff;
62 header[2] = (inl >> 16) & 0xff;
63 header[3] = (inl >> 8) & 0xff;
64 header[4] = inl & 0xff;
65 int ret = BIO_write(bio->next_bio, header, sizeof(header));
66 if (ret <= 0) {
67 BIO_copy_next_retry(bio);
68 return ret;
69 }
70
71 // Write the buffer.
72 ret = BIO_write(bio->next_bio, in, inl);
73 if (ret < 0 || (inl > 0 && ret == 0)) {
74 BIO_copy_next_retry(bio);
75 return ret;
76 }
77 assert(ret == inl);
78 return ret;
79 }
80
PacketedRead(BIO * bio,char * out,int outl)81 static int PacketedRead(BIO *bio, char *out, int outl) {
82 if (bio->next_bio == NULL) {
83 return 0;
84 }
85
86 BIO_clear_retry_flags(bio);
87
88 // Read the opcode.
89 uint8_t opcode;
90 int ret = ReadAll(bio->next_bio, &opcode, sizeof(opcode));
91 if (ret <= 0) {
92 BIO_copy_next_retry(bio);
93 return ret;
94 }
95
96 if (opcode == kOpcodeTimeout) {
97 // Process the timeout.
98 uint8_t buf[8];
99 ret = ReadAll(bio->next_bio, buf, sizeof(buf));
100 if (ret <= 0) {
101 BIO_copy_next_retry(bio);
102 return ret;
103 }
104 uint64_t timeout = (static_cast<uint64_t>(buf[0]) << 56) |
105 (static_cast<uint64_t>(buf[1]) << 48) |
106 (static_cast<uint64_t>(buf[2]) << 40) |
107 (static_cast<uint64_t>(buf[3]) << 32) |
108 (static_cast<uint64_t>(buf[4]) << 24) |
109 (static_cast<uint64_t>(buf[5]) << 16) |
110 (static_cast<uint64_t>(buf[6]) << 8) |
111 static_cast<uint64_t>(buf[7]);
112 timeout /= 1000; // Convert nanoseconds to microseconds.
113 timeval *out_timeout = reinterpret_cast<timeval *>(bio->ptr);
114 assert(out_timeout->tv_usec == 0);
115 assert(out_timeout->tv_sec == 0);
116 out_timeout->tv_usec = timeout % 1000000;
117 out_timeout->tv_sec = timeout / 1000000;
118
119 // Send an ACK to the peer.
120 ret = BIO_write(bio->next_bio, &kOpcodeTimeoutAck, 1);
121 if (ret <= 0) {
122 return ret;
123 }
124 assert(ret == 1);
125
126 // Signal to the caller to retry the read, after processing the
127 // new clock.
128 BIO_set_retry_read(bio);
129 return -1;
130 }
131
132 if (opcode != kOpcodePacket) {
133 fprintf(stderr, "Unknown opcode, %u\n", opcode);
134 return -1;
135 }
136
137 // Read the length prefix.
138 uint8_t len_bytes[4];
139 ret = ReadAll(bio->next_bio, len_bytes, sizeof(len_bytes));
140 if (ret <= 0) {
141 BIO_copy_next_retry(bio);
142 return ret;
143 }
144
145 uint32_t len = (len_bytes[0] << 24) | (len_bytes[1] << 16) |
146 (len_bytes[2] << 8) | len_bytes[3];
147 uint8_t *buf = (uint8_t *)OPENSSL_malloc(len);
148 if (buf == NULL) {
149 return -1;
150 }
151 ret = ReadAll(bio->next_bio, buf, len);
152 if (ret <= 0) {
153 fprintf(stderr, "Packeted BIO was truncated\n");
154 return -1;
155 }
156
157 if (outl > (int)len) {
158 outl = len;
159 }
160 memcpy(out, buf, outl);
161 OPENSSL_free(buf);
162 return outl;
163 }
164
PacketedCtrl(BIO * bio,int cmd,long num,void * ptr)165 static long PacketedCtrl(BIO *bio, int cmd, long num, void *ptr) {
166 if (bio->next_bio == NULL) {
167 return 0;
168 }
169 BIO_clear_retry_flags(bio);
170 int ret = BIO_ctrl(bio->next_bio, cmd, num, ptr);
171 BIO_copy_next_retry(bio);
172 return ret;
173 }
174
PacketedNew(BIO * bio)175 static int PacketedNew(BIO *bio) {
176 bio->init = 1;
177 return 1;
178 }
179
PacketedFree(BIO * bio)180 static int PacketedFree(BIO *bio) {
181 if (bio == NULL) {
182 return 0;
183 }
184
185 bio->init = 0;
186 return 1;
187 }
188
PacketedCallbackCtrl(BIO * bio,int cmd,bio_info_cb fp)189 static long PacketedCallbackCtrl(BIO *bio, int cmd, bio_info_cb fp) {
190 if (bio->next_bio == NULL) {
191 return 0;
192 }
193 return BIO_callback_ctrl(bio->next_bio, cmd, fp);
194 }
195
196 const BIO_METHOD g_packeted_bio_method = {
197 BIO_TYPE_FILTER,
198 "packeted bio",
199 PacketedWrite,
200 PacketedRead,
201 NULL /* puts */,
202 NULL /* gets */,
203 PacketedCtrl,
204 PacketedNew,
205 PacketedFree,
206 PacketedCallbackCtrl,
207 };
208
209 } // namespace
210
PacketedBioCreate(timeval * out_timeout)211 ScopedBIO PacketedBioCreate(timeval *out_timeout) {
212 ScopedBIO bio(BIO_new(&g_packeted_bio_method));
213 if (!bio) {
214 return nullptr;
215 }
216 bio->ptr = out_timeout;
217 return bio;
218 }
219