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#include "shared/net/connection.hh"
namespace shared {
namespace net {
connection::connection(const socket_t& rsock) {
const std::string peer_address = get_socket_peer_address(rsock);
const std::string peer_port = get_socket_peer_port(rsock);
// Open up a connected usock based on the state of the connected rsock.
const socket_t usock = [&]() -> socket_t {
constexpr addrinfo hints = {.ai_flags = AI_PASSIVE,
.ai_family = AF_INET,
.ai_socktype = SOCK_DGRAM};
const std::string host_address = get_socket_host_address(rsock);
const std::string host_port = get_socket_host_port(rsock);
const auto host_info = get_addr_info(host_address, host_port, &hints);
const socket_t usock = make_socket(host_info.get());
bind_socket(usock, host_info.get());
const auto peer_info = get_addr_info(peer_address, peer_port, &hints);
connect_socket(usock, peer_info.get());
return usock;
}();
nonblock_socket(usock);
nonblock_socket(rsock);
this->socks.emplace(sockets{.rsock = rsock,
.usock = usock,
.address = peer_address,
.port = peer_port});
}
connection::connection(connection&& other) noexcept {
std::swap(this->socks, other.socks);
std::swap(this->bad_reason, other.bad_reason);
other.socks.reset();
}
connection& connection::operator=(connection&& other) noexcept {
std::swap(this->socks, other.socks);
std::swap(this->bad_reason, other.bad_reason);
other.socks.reset();
return *this;
}
connection::~connection() noexcept { this->close(); }
void connection::rsend_packet(const rpacket_t& packet) noexcept {
this->rpackets.push_back(packet);
}
void connection::usend_packet(const upacket_t& packet) noexcept {
this->upackets.push_back(packet);
}
void connection::rsend_packet(rpacket&& packet) noexcept {
this->rsend_packet(std::make_shared<rpacket>(std::move(packet)));
}
void connection::usend_packet(upacket&& packet) noexcept {
this->usend_packet(std::make_shared<upacket>(std::move(packet)));
}
std::optional<proto::packet> connection::rrecv_packet() noexcept {
if (!this->good()) {
return std::nullopt;
}
const socket_t sock = this->socks->rsock;
// Get the size of the backlog, early out of there's nothing there yet.
const auto backlog_size = shared::net::get_backlog_size(sock);
if (backlog_size < sizeof(packet_header_t)) {
return std::nullopt;
}
const packet_header_t read_packet_size = [&]() {
packet_header_t ret;
recv(sock, &ret, sizeof(packet_header_t), MSG_PEEK);
return ntohl(ret);
}();
if (backlog_size < read_packet_size) { // data not there yet
return std::nullopt;
}
if (read_packet_size < sizeof(packet_header_t)) {
this->bad_reason.emplace("received packet too small");
return std::nullopt;
}
if (read_packet_size >= MAX_PACKET_SIZE) {
this->bad_reason.emplace("received packet size exceeded limit");
return std::nullopt;
}
// Read the actual packet now, based on our claimed size.
std::string data(read_packet_size, '\0');
if (const auto result = read(sock, std::data(data), read_packet_size);
result == -1) {
this->bad_reason = shared::net::get_errno_error();
return std::nullopt;
} else if (result != read_packet_size) {
return std::nullopt; // this shouldn't happen?
}
data = {std::begin(data) + sizeof(packet_header_t), std::end(data)};
// possible compression bomb :)
if (const auto decompress = shared::maybe_decompress_string(data);
decompress.has_value()) {
data = *decompress;
} else {
return std::nullopt;
}
// Parse the packet, ignoring the header.
proto::packet packet;
if (!packet.ParseFromString(data)) {
return std::nullopt;
}
return packet;
}
std::optional<proto::packet> connection::urecv_packet() noexcept {
const socket_t sock = this->socks->usock;
restart:
if (!this->good()) {
return std::nullopt;
}
const auto packet_size = shared::net::get_backlog_size(sock);
if (packet_size == 0) {
return std::nullopt;
}
std::string data(packet_size, '\0');
if (const auto result = read(sock, std::data(data), packet_size);
result == -1) {
if (errno == ECONNREFUSED) { // icmp, ignore it
goto restart;
}
this->bad_reason = shared::net::get_errno_error();
return std::nullopt;
} else if (static_cast<decltype(packet_size)>(result) != packet_size) {
return std::nullopt; // shouldn't happen
}
if (const auto decompress = shared::maybe_decompress_string(data);
decompress.has_value()) {
data = *decompress;
} else {
goto restart;
}
proto::packet packet;
if (!packet.ParseFromString(data)) {
goto restart;
}
return packet;
}
std::optional<proto::packet> connection::recv_packet() noexcept {
if (const auto ret = urecv_packet(); ret.has_value()) {
return ret;
}
return rrecv_packet();
}
bool connection::maybe_send(const packet& packet,
const socket_t& sock) noexcept {
if (!this->good()) {
return false;
}
const auto& data = packet.data;
if (const auto result = write(sock, std::data(data), std::size(data));
result == -1) {
if (errno == EAGAIN || errno == EWOULDBLOCK) {
return false;
}
this->bad_reason.emplace(get_errno_error());
return false;
} else if (static_cast<std::size_t>(result) != std::size(data)) {
return false;
}
return true;
}
void connection::poll() {
const auto erase_send = [this](auto& packets, const socket_t& sock) {
const auto it =
std::find_if(std::begin(packets), std::end(packets),
[&, this](const auto& packet) {
return !this->maybe_send(*packet, sock);
});
packets.erase(std::begin(packets), it);
};
erase_send(this->upackets, this->socks->usock);
erase_send(this->rpackets, this->socks->rsock);
}
void connection::close() {
if (this->socks.has_value()) {
shared::net::close_socket(socks->rsock);
shared::net::close_socket(socks->usock);
}
this->socks.reset();
}
} // namespace net
} // namespace shared
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