#include "node_crypto_bio.h"

#include "openssl/bio.h"

#include "util.h"

#include "util-inl.h"

#include <string.h>

namespace node {

const BIO_METHOD NodeBIO::method = {

BIO_TYPE_MEM,

"node.js SSL buffer",

NodeBIO::Write,

NodeBIO::Read,

NodeBIO::Puts,

NodeBIO::Gets,

NodeBIO::Ctrl,

NodeBIO::New,

NodeBIO::Free,

nullptr

};

BIO* NodeBIO::New() {

// The const_cast doesn't violate const correctness. OpenSSL's usage of

// BIO_METHOD is effectively const but BIO_new() takes a non-const argument.

return BIO_new(const_cast<BIO_METHOD*>(&method));

}

void NodeBIO::AssignEnvironment(Environment* env) {

env_ = env;

}

int NodeBIO::New(BIO* bio) {

bio->ptr = new NodeBIO();

// XXX Why am I doing it?!

bio->shutdown = 1;

bio->init = 1;

bio->num = -1;

return 1;

}

int NodeBIO::Free(BIO* bio) {

if (bio == nullptr)

return 0;

if (bio->shutdown) {

if (bio->init && bio->ptr != nullptr) {

delete FromBIO(bio);

bio->ptr = nullptr;

}

}

return 1;

}

int NodeBIO::Read(BIO* bio, char* out, int len) {

int bytes;

BIO_clear_retry_flags(bio);

bytes = FromBIO(bio)->Read(out, len);

if (bytes == 0) {

bytes = bio->num;

if (bytes != 0) {

BIO_set_retry_read(bio);

}

}

return bytes;

}

char* NodeBIO::Peek(size_t* size) {

*size = read_head_->write_pos_ - read_head_->read_pos_;

return read_head_->data_ + read_head_->read_pos_;

}

size_t NodeBIO::PeekMultiple(char** out, size_t* size, size_t* count) {

Buffer* pos = read_head_;

size_t max = *count;

size_t total = 0;

size_t i;

for (i = 0; i < max; i++) {

size[i] = pos->write_pos_ - pos->read_pos_;

total += size[i];

out[i] = pos->data_ + pos->read_pos_;

/* Don't get past write head */

if (pos == write_head_)

break;

else

pos = pos->next_;

}

if (i == max)

*count = i;

else

*count = i + 1;

return total;

}

int NodeBIO::Write(BIO* bio, const char* data, int len) {

BIO_clear_retry_flags(bio);

FromBIO(bio)->Write(data, len);

return len;

}

int NodeBIO::Puts(BIO* bio, const char* str) {

return Write(bio, str, strlen(str));

}

int NodeBIO::Gets(BIO* bio, char* out, int size) {

NodeBIO* nbio = FromBIO(bio);

if (nbio->Length() == 0)

return 0;

int i = nbio->IndexOf('\n', size);

// Include '\n', if it's there. If not, don't read off the end.

if (i < size && i >= 0 && static_cast<size_t>(i) < nbio->Length())

i++;

// Shift `i` a bit to nullptr-terminate string later

if (size == i)

i--;

// Flush read data

nbio->Read(out, i);

out[i] = 0;

return i;

}

long NodeBIO::Ctrl(BIO* bio, int cmd, long num, void* ptr) {

NodeBIO* nbio;

long ret;

nbio = FromBIO(bio);

ret = 1;

switch (cmd) {

case BIO_CTRL_RESET:

nbio->Reset();

break;

case BIO_CTRL_EOF:

ret = nbio->Length() == 0;

break;

case BIO_C_SET_BUF_MEM_EOF_RETURN:

bio->num = num;

break;

case BIO_CTRL_INFO:

ret = nbio->Length();

if (ptr != nullptr)

*reinterpret_cast<void**>(ptr) = nullptr;

break;

case BIO_C_SET_BUF_MEM:

CHECK(0 && "Can't use SET_BUF_MEM_PTR with NodeBIO");

abort();

break;

case BIO_C_GET_BUF_MEM_PTR:

CHECK(0 && "Can't use GET_BUF_MEM_PTR with NodeBIO");

ret = 0;

break;

case BIO_CTRL_GET_CLOSE:

ret = bio->shutdown;

break;

case BIO_CTRL_SET_CLOSE:

bio->shutdown = num;

break;

case BIO_CTRL_WPENDING:

ret = 0;

break;

case BIO_CTRL_PENDING:

ret = nbio->Length();

break;

case BIO_CTRL_DUP:

case BIO_CTRL_FLUSH:

ret = 1;

break;

case BIO_CTRL_PUSH:

case BIO_CTRL_POP:

default:

ret = 0;

break;

}

return ret;

}

void NodeBIO::TryMoveReadHead() {

// `read_pos_` and `write_pos_` means the position of the reader and writer

// inside the buffer, respectively. When they're equal - its safe to reset

// them, because both reader and writer will continue doing their stuff

// from new (zero) positions.

while (read_head_->read_pos_ != 0 &&

read_head_->read_pos_ == read_head_->write_pos_) {

// Reset positions

read_head_->read_pos_ = 0;

read_head_->write_pos_ = 0;

// Move read_head_ forward, just in case if there're still some data to

// read in the next buffer.

if (read_head_ != write_head_)

read_head_ = read_head_->next_;

}

}

size_t NodeBIO::Read(char* out, size_t size) {

size_t bytes_read = 0;

size_t expected = Length() > size ? size : Length();

size_t offset = 0;

size_t left = size;

while (bytes_read < expected) {

CHECK_LE(read_head_->read_pos_, read_head_->write_pos_);

size_t avail = read_head_->write_pos_ - read_head_->read_pos_;

if (avail > left)

avail = left;

// Copy data

if (out != nullptr)

memcpy(out + offset, read_head_->data_ + read_head_->read_pos_, avail);

read_head_->read_pos_ += avail;

// Move pointers

bytes_read += avail;

offset += avail;

left -= avail;

TryMoveReadHead();

}

CHECK_EQ(expected, bytes_read);

length_ -= bytes_read;

// Free all empty buffers, but write_head's child

FreeEmpty();

return bytes_read;

}

void NodeBIO::FreeEmpty() {

if (write_head_ == nullptr)

return;

Buffer* child = write_head_->next_;

if (child == write_head_ || child == read_head_)

return;

Buffer* cur = child->next_;

if (cur == write_head_ || cur == read_head_)

return;

Buffer* prev = child;

while (cur != read_head_) {

CHECK_NE(cur, write_head_);

CHECK_EQ(cur->write_pos_, cur->read_pos_);

Buffer* next = cur->next_;

delete cur;

cur = next;

}

prev->next_ = cur;

}

size_t NodeBIO::IndexOf(char delim, size_t limit) {

size_t bytes_read = 0;

size_t max = Length() > limit ? limit : Length();

size_t left = limit;

Buffer* current = read_head_;

while (bytes_read < max) {

CHECK_LE(current->read_pos_, current->write_pos_);

size_t avail = current->write_pos_ - current->read_pos_;

if (avail > left)

avail = left;

// Walk through data

char* tmp = current->data_ + current->read_pos_;

size_t off = 0;

while (off < avail && *tmp != delim) {

off++;

tmp++;

}

// Move pointers

bytes_read += off;

left -= off;

// Found `delim`

if (off != avail) {

return bytes_read;

}

// Move to next buffer

if (current->read_pos_ + avail == current->len_) {

current = current->next_;

}

}

CHECK_EQ(max, bytes_read);

return max;

}

void NodeBIO::Write(const char* data, size_t size) {

size_t offset = 0;

size_t left = size;

// Allocate initial buffer if the ring is empty

TryAllocateForWrite(left);

while (left > 0) {

size_t to_write = left;

CHECK_LE(write_head_->write_pos_, write_head_->len_);

size_t avail = write_head_->len_ - write_head_->write_pos_;

if (to_write > avail)

to_write = avail;

// Copy data

memcpy(write_head_->data_ + write_head_->write_pos_,

data + offset,

to_write);

// Move pointers

left -= to_write;

offset += to_write;

length_ += to_write;

write_head_->write_pos_ += to_write;

CHECK_LE(write_head_->write_pos_, write_head_->len_);

// Go to next buffer if there still are some bytes to write

if (left != 0) {

CHECK_EQ(write_head_->write_pos_, write_head_->len_);

TryAllocateForWrite(left);

write_head_ = write_head_->next_;

// Additionally, since we're moved to the next buffer, read head

// may be moved as well.

TryMoveReadHead();

}

}

CHECK_EQ(left, 0);

}

char* NodeBIO::PeekWritable(size_t* size) {

TryAllocateForWrite(*size);

size_t available = write_head_->len_ - write_head_->write_pos_;

if (*size != 0 && available > *size)

available = *size;

else

*size = available;

return write_head_->data_ + write_head_->write_pos_;

}

void NodeBIO::Commit(size_t size) {

write_head_->write_pos_ += size;

length_ += size;

CHECK_LE(write_head_->write_pos_, write_head_->len_);

// Allocate new buffer if write head is full,

// and there're no other place to go

TryAllocateForWrite(0);

if (write_head_->write_pos_ == write_head_->len_) {

write_head_ = write_head_->next_;

// Additionally, since we're moved to the next buffer, read head

// may be moved as well.

TryMoveReadHead();

}

}

void NodeBIO::TryAllocateForWrite(size_t hint) {

Buffer* w = write_head_;

Buffer* r = read_head_;

// If write head is full, next buffer is either read head or not empty.

if (w == nullptr ||

(w->write_pos_ == w->len_ &&

(w->next_ == r || w->next_->write_pos_ != 0))) {

size_t len = w == nullptr ? initial_ :

kThroughputBufferLength;

if (len < hint)

len = hint;

Buffer* next = new Buffer(env_, len);

if (w == nullptr) {

next->next_ = next;

write_head_ = next;

read_head_ = next;

} else {

next->next_ = w->next_;

w->next_ = next;

}

}

}

void NodeBIO::Reset() {

if (read_head_ == nullptr)

return;

while (read_head_->read_pos_ != read_head_->write_pos_) {

CHECK(read_head_->write_pos_ > read_head_->read_pos_);

length_ -= read_head_->write_pos_ - read_head_->read_pos_;

read_head_->write_pos_ = 0;

read_head_->read_pos_ = 0;

read_head_ = read_head_->next_;

}

write_head_ = read_head_;

CHECK_EQ(length_, 0);

}

NodeBIO::~NodeBIO() {

if (read_head_ == nullptr)

return;

Buffer* current = read_head_;

do {

Buffer* next = current->next_;

delete current;

current = next;

} while (current != read_head_);

read_head_ = nullptr;

write_head_ = nullptr;

}

} // namespace node