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
25namespace {
26
27extern const BIO_METHOD g_packeted_bio_method;
28
29const uint8_t kOpcodePacket = 'P';
30const uint8_t kOpcodeTimeout = 'T';
31const 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.
35static 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
51static 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
81static 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
165static 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
175static int PacketedNew(BIO *bio) {
176  bio->init = 1;
177  return 1;
178}
179
180static int PacketedFree(BIO *bio) {
181  if (bio == NULL) {
182    return 0;
183  }
184
185  bio->init = 0;
186  return 1;
187}
188
189static 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
196const 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
211ScopedBIO 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