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/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include "packeted_bio.h"
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <string.h>
#include <openssl/mem.h>
namespace {
extern const BIO_METHOD g_packeted_bio_method;
const uint8_t kOpcodePacket = 'P';
const uint8_t kOpcodeTimeout = 'T';
const uint8_t kOpcodeTimeoutAck = 't';
struct PacketedBio {
PacketedBio(timeval *clock_arg, bool advance_clock_arg)
: clock(clock_arg), advance_clock(advance_clock_arg) {
memset(&timeout, 0, sizeof(timeout));
memset(&read_deadline, 0, sizeof(read_deadline));
}
bool HasTimeout() const {
return timeout.tv_sec != 0 || timeout.tv_usec != 0;
}
bool CanRead() const {
if (read_deadline.tv_sec == 0 && read_deadline.tv_usec == 0) {
return true;
}
if (clock->tv_sec == read_deadline.tv_sec) {
return clock->tv_usec < read_deadline.tv_usec;
}
return clock->tv_sec < read_deadline.tv_sec;
}
timeval timeout;
timeval *clock;
timeval read_deadline;
bool advance_clock;
};
PacketedBio *GetData(BIO *bio) {
if (bio->method != &g_packeted_bio_method) {
return NULL;
}
return (PacketedBio *)bio->ptr;
}
// ReadAll reads |len| bytes from |bio| into |out|. It returns 1 on success and
// 0 or -1 on error.
static int ReadAll(BIO *bio, uint8_t *out, size_t len) {
while (len > 0) {
int chunk_len = INT_MAX;
if (len <= INT_MAX) {
chunk_len = (int)len;
}
int ret = BIO_read(bio, out, chunk_len);
if (ret <= 0) {
return ret;
}
out += ret;
len -= ret;
}
return 1;
}
static int PacketedWrite(BIO *bio, const char *in, int inl) {
if (bio->next_bio == NULL) {
return 0;
}
BIO_clear_retry_flags(bio);
// Write the header.
uint8_t header[5];
header[0] = kOpcodePacket;
header[1] = (inl >> 24) & 0xff;
header[2] = (inl >> 16) & 0xff;
header[3] = (inl >> 8) & 0xff;
header[4] = inl & 0xff;
int ret = BIO_write(bio->next_bio, header, sizeof(header));
if (ret <= 0) {
BIO_copy_next_retry(bio);
return ret;
}
// Write the buffer.
ret = BIO_write(bio->next_bio, in, inl);
if (ret < 0 || (inl > 0 && ret == 0)) {
BIO_copy_next_retry(bio);
return ret;
}
assert(ret == inl);
return ret;
}
static int PacketedRead(BIO *bio, char *out, int outl) {
PacketedBio *data = GetData(bio);
if (bio->next_bio == NULL) {
return 0;
}
BIO_clear_retry_flags(bio);
for (;;) {
// Check if the read deadline has passed.
if (!data->CanRead()) {
BIO_set_retry_read(bio);
return -1;
}
// Read the opcode.
uint8_t opcode;
int ret = ReadAll(bio->next_bio, &opcode, sizeof(opcode));
if (ret <= 0) {
BIO_copy_next_retry(bio);
return ret;
}
if (opcode == kOpcodeTimeout) {
// The caller is required to advance any pending timeouts before
// continuing.
if (data->HasTimeout()) {
fprintf(stderr, "Unprocessed timeout!\n");
return -1;
}
// Process the timeout.
uint8_t buf[8];
ret = ReadAll(bio->next_bio, buf, sizeof(buf));
if (ret <= 0) {
BIO_copy_next_retry(bio);
return ret;
}
uint64_t timeout = (static_cast<uint64_t>(buf[0]) << 56) |
(static_cast<uint64_t>(buf[1]) << 48) |
(static_cast<uint64_t>(buf[2]) << 40) |
(static_cast<uint64_t>(buf[3]) << 32) |
(static_cast<uint64_t>(buf[4]) << 24) |
(static_cast<uint64_t>(buf[5]) << 16) |
(static_cast<uint64_t>(buf[6]) << 8) |
static_cast<uint64_t>(buf[7]);
timeout /= 1000; // Convert nanoseconds to microseconds.
data->timeout.tv_usec = timeout % 1000000;
data->timeout.tv_sec = timeout / 1000000;
// Send an ACK to the peer.
ret = BIO_write(bio->next_bio, &kOpcodeTimeoutAck, 1);
if (ret <= 0) {
return ret;
}
assert(ret == 1);
if (!data->advance_clock) {
// Signal to the caller to retry the read, after advancing the clock.
BIO_set_retry_read(bio);
return -1;
}
PacketedBioAdvanceClock(bio);
continue;
}
if (opcode != kOpcodePacket) {
fprintf(stderr, "Unknown opcode, %u\n", opcode);
return -1;
}
// Read the length prefix.
uint8_t len_bytes[4];
ret = ReadAll(bio->next_bio, len_bytes, sizeof(len_bytes));
if (ret <= 0) {
BIO_copy_next_retry(bio);
return ret;
}
uint32_t len = (len_bytes[0] << 24) | (len_bytes[1] << 16) |
(len_bytes[2] << 8) | len_bytes[3];
uint8_t *buf = (uint8_t *)OPENSSL_malloc(len);
if (buf == NULL) {
return -1;
}
ret = ReadAll(bio->next_bio, buf, len);
if (ret <= 0) {
fprintf(stderr, "Packeted BIO was truncated\n");
return -1;
}
if (outl > (int)len) {
outl = len;
}
memcpy(out, buf, outl);
OPENSSL_free(buf);
return outl;
}
}
static long PacketedCtrl(BIO *bio, int cmd, long num, void *ptr) {
if (cmd == BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT) {
memcpy(&GetData(bio)->read_deadline, ptr, sizeof(timeval));
return 1;
}
if (bio->next_bio == NULL) {
return 0;
}
BIO_clear_retry_flags(bio);
int ret = BIO_ctrl(bio->next_bio, cmd, num, ptr);
BIO_copy_next_retry(bio);
return ret;
}
static int PacketedNew(BIO *bio) {
bio->init = 1;
return 1;
}
static int PacketedFree(BIO *bio) {
if (bio == NULL) {
return 0;
}
delete GetData(bio);
bio->init = 0;
return 1;
}
static long PacketedCallbackCtrl(BIO *bio, int cmd, bio_info_cb fp) {
if (bio->next_bio == NULL) {
return 0;
}
return BIO_callback_ctrl(bio->next_bio, cmd, fp);
}
const BIO_METHOD g_packeted_bio_method = {
BIO_TYPE_FILTER,
"packeted bio",
PacketedWrite,
PacketedRead,
NULL /* puts */,
NULL /* gets */,
PacketedCtrl,
PacketedNew,
PacketedFree,
PacketedCallbackCtrl,
};
} // namespace
bssl::UniquePtr<BIO> PacketedBioCreate(timeval *clock, bool advance_clock) {
bssl::UniquePtr<BIO> bio(BIO_new(&g_packeted_bio_method));
if (!bio) {
return nullptr;
}
bio->ptr = new PacketedBio(clock, advance_clock);
return bio;
}
bool PacketedBioAdvanceClock(BIO *bio) {
PacketedBio *data = GetData(bio);
if (data == nullptr) {
return false;
}
if (!data->HasTimeout()) {
return false;
}
data->clock->tv_usec += data->timeout.tv_usec;
data->clock->tv_sec += data->clock->tv_usec / 1000000;
data->clock->tv_usec %= 1000000;
data->clock->tv_sec += data->timeout.tv_sec;
memset(&data->timeout, 0, sizeof(data->timeout));
return true;
}