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authorRubidium <rubidium@openttd.org>2021-04-18 10:23:41 +0200
committerrubidium42 <rubidium42@users.noreply.github.com>2021-04-24 20:42:01 +0200
commitd4f027c03bfc5f632b7d63c125dfa57a7ba89926 (patch)
treebce76afc0a253cf8128153fcb7b5ebae36c93434 /src
parent98aa561cf759f75971afd5dfc4d42e6921a8ab1a (diff)
downloadopenttd-d4f027c03bfc5f632b7d63c125dfa57a7ba89926.tar.xz
Codechange: encapsulate writing data from Packets into sockets/files/buffers to prevent packet state modifications outside of the Packet
Diffstat (limited to 'src')
-rw-r--r--src/network/core/packet.h52
-rw-r--r--src/network/core/tcp.cpp6
-rw-r--r--src/network/core/tcp_listen.h4
-rw-r--r--src/network/core/udp.cpp2
-rw-r--r--src/network/network_client.cpp36
-rw-r--r--src/network/network_content.cpp16
6 files changed, 90 insertions, 26 deletions
diff --git a/src/network/core/packet.h b/src/network/core/packet.h
index 3eee0522f..b091d8a7e 100644
--- a/src/network/core/packet.h
+++ b/src/network/core/packet.h
@@ -89,6 +89,58 @@ public:
size_t RemainingBytesToTransfer() const;
/**
+ * Transfer data from the packet to the given function. It starts reading at the
+ * position the last transfer stopped.
+ * See Packet::TransferIn for more information about transferring data to functions.
+ * @param transfer_function The function to pass the buffer as second parameter and the
+ * amount to write as third parameter. It returns the amount that
+ * was written or -1 upon errors.
+ * @param limit The maximum amount of bytes to transfer.
+ * @param destination The first parameter of the transfer function.
+ * @param args The fourth and further parameters to the transfer function, if any.
+ * @return The return value of the transfer_function.
+ */
+ template <
+ typename A = size_t, ///< The type for the amount to be passed, so it can be cast to the right type.
+ typename F, ///< The type of the function.
+ typename D, ///< The type of the destination.
+ typename ... Args> ///< The types of the remaining arguments to the function.
+ ssize_t TransferOutWithLimit(F transfer_function, size_t limit, D destination, Args&& ... args)
+ {
+ size_t amount = std::min(this->RemainingBytesToTransfer(), limit);
+ if (amount == 0) return 0;
+
+ assert(this->pos < this->buffer.size());
+ assert(this->pos + amount <= this->buffer.size());
+ /* Making buffer a char means casting a lot in the Recv/Send functions. */
+ const char *output_buffer = reinterpret_cast<const char*>(this->buffer + this->pos);
+ ssize_t bytes = transfer_function(destination, output_buffer, static_cast<A>(amount), std::forward<Args>(args)...);
+ if (bytes > 0) this->pos += bytes;
+ return bytes;
+ }
+
+ /**
+ * Transfer data from the packet to the given function. It starts reading at the
+ * position the last transfer stopped.
+ * See Packet::TransferIn for more information about transferring data to functions.
+ * @param transfer_function The function to pass the buffer as second parameter and the
+ * amount to write as third parameter. It returns the amount that
+ * was written or -1 upon errors.
+ * @param destination The first parameter of the transfer function.
+ * @param args The fourth and further parameters to the transfer function, if any.
+ * @tparam A The type for the amount to be passed, so it can be cast to the right type.
+ * @tparam F The type of the transfer_function.
+ * @tparam D The type of the destination.
+ * @tparam Args The types of the remaining arguments to the function.
+ * @return The return value of the transfer_function.
+ */
+ template <typename A = size_t, typename F, typename D, typename ... Args>
+ ssize_t TransferOut(F transfer_function, D destination, Args&& ... args)
+ {
+ return TransferOutWithLimit<A>(transfer_function, std::numeric_limits<size_t>::max(), destination, std::forward<Args>(args)...);
+ }
+
+ /**
* Transfer data from the given function into the packet. It starts writing at the
* position the last transfer stopped.
*
diff --git a/src/network/core/tcp.cpp b/src/network/core/tcp.cpp
index aa1e1cbed..ab18f47a8 100644
--- a/src/network/core/tcp.cpp
+++ b/src/network/core/tcp.cpp
@@ -103,7 +103,7 @@ SendPacketsState NetworkTCPSocketHandler::SendPackets(bool closing_down)
p = this->packet_queue;
while (p != nullptr) {
- res = send(this->sock, (const char*)p->buffer + p->pos, p->size - p->pos, 0);
+ res = p->TransferOut<int>(send, this->sock, 0);
if (res == -1) {
int err = GET_LAST_ERROR();
if (err != EWOULDBLOCK) {
@@ -122,10 +122,8 @@ SendPacketsState NetworkTCPSocketHandler::SendPackets(bool closing_down)
return SPS_CLOSED;
}
- p->pos += res;
-
/* Is this packet sent? */
- if (p->pos == p->size) {
+ if (p->RemainingBytesToTransfer() == 0) {
/* Go to the next packet */
this->packet_queue = p->next;
delete p;
diff --git a/src/network/core/tcp_listen.h b/src/network/core/tcp_listen.h
index 1f073aa73..53a3d57cc 100644
--- a/src/network/core/tcp_listen.h
+++ b/src/network/core/tcp_listen.h
@@ -63,7 +63,7 @@ public:
DEBUG(net, 1, "[%s] Banned ip tried to join (%s), refused", Tsocket::GetName(), entry.c_str());
- if (send(s, (const char*)p.buffer, p.size, 0) < 0) {
+ if (p.TransferOut<int>(send, s, 0) < 0) {
DEBUG(net, 0, "send failed with error %d", GET_LAST_ERROR());
}
closesocket(s);
@@ -80,7 +80,7 @@ public:
Packet p(Tfull_packet);
p.PrepareToSend();
- if (send(s, (const char*)p.buffer, p.size, 0) < 0) {
+ if (p.TransferOut<int>(send, s, 0) < 0) {
DEBUG(net, 0, "send failed with error %d", GET_LAST_ERROR());
}
closesocket(s);
diff --git a/src/network/core/udp.cpp b/src/network/core/udp.cpp
index 398f53142..8e476f4e2 100644
--- a/src/network/core/udp.cpp
+++ b/src/network/core/udp.cpp
@@ -99,7 +99,7 @@ void NetworkUDPSocketHandler::SendPacket(Packet *p, NetworkAddress *recv, bool a
}
/* Send the buffer */
- int res = sendto(s.second, (const char*)p->buffer, p->size, 0, (const struct sockaddr *)send.GetAddress(), send.GetAddressLength());
+ ssize_t res = p->TransferOut<int>(sendto, s.second, 0, (const struct sockaddr *)send.GetAddress(), send.GetAddressLength());
DEBUG(net, 7, "[udp] sendto(%s)", send.GetAddressAsString().c_str());
/* Check for any errors, but ignore it otherwise */
diff --git a/src/network/network_client.cpp b/src/network/network_client.cpp
index 10b4fd141..6156dc486 100644
--- a/src/network/network_client.cpp
+++ b/src/network/network_client.cpp
@@ -35,7 +35,6 @@
/* This file handles all the client-commands */
-
/** Read some packets, and when do use that data as initial load filter. */
struct PacketReader : LoadFilter {
static const size_t CHUNK = 32 * 1024; ///< 32 KiB chunks of memory.
@@ -60,34 +59,37 @@ struct PacketReader : LoadFilter {
}
/**
+ * Simple wrapper around fwrite to be able to pass it to Packet's TransferOut.
+ * @param destination The reader to add the data to.
+ * @param source The buffer to read data from.
+ * @param amount The number of bytes to copy.
+ * @return The number of bytes that were copied.
+ */
+ static inline ssize_t TransferOutMemCopy(PacketReader *destination, const char *source, size_t amount)
+ {
+ memcpy(destination->buf, source, amount);
+ destination->buf += amount;
+ destination->written_bytes += amount;
+ return amount;
+ }
+
+ /**
* Add a packet to this buffer.
* @param p The packet to add.
*/
- void AddPacket(const Packet *p)
+ void AddPacket(Packet *p)
{
assert(this->read_bytes == 0);
-
- size_t in_packet = p->size - p->pos;
- size_t to_write = std::min<size_t>(this->bufe - this->buf, in_packet);
- const byte *pbuf = p->buffer + p->pos;
-
- this->written_bytes += in_packet;
- if (to_write != 0) {
- memcpy(this->buf, pbuf, to_write);
- this->buf += to_write;
- }
+ p->TransferOutWithLimit(TransferOutMemCopy, this->bufe - this->buf, this);
/* Did everything fit in the current chunk, then we're done. */
- if (to_write == in_packet) return;
+ if (p->RemainingBytesToTransfer() == 0) return;
/* Allocate a new chunk and add the remaining data. */
- pbuf += to_write;
- to_write = in_packet - to_write;
this->blocks.push_back(this->buf = CallocT<byte>(CHUNK));
this->bufe = this->buf + CHUNK;
- memcpy(this->buf, pbuf, to_write);
- this->buf += to_write;
+ p->TransferOutWithLimit(TransferOutMemCopy, this->bufe - this->buf, this);
}
size_t Read(byte *rbuf, size_t size) override
diff --git a/src/network/network_content.cpp b/src/network/network_content.cpp
index 0220f890b..529225235 100644
--- a/src/network/network_content.cpp
+++ b/src/network/network_content.cpp
@@ -459,6 +459,18 @@ static bool GunzipFile(const ContentInfo *ci)
#endif /* defined(WITH_ZLIB) */
}
+/**
+ * Simple wrapper around fwrite to be able to pass it to Packet's TransferOut.
+ * @param file The file to write data to.
+ * @param buffer The buffer to write to the file.
+ * @param amount The number of bytes to write.
+ * @return The number of bytes that were written.
+ */
+static inline ssize_t TransferOutFWrite(FILE *file, const char *buffer, size_t amount)
+{
+ return fwrite(buffer, 1, amount, file);
+}
+
bool ClientNetworkContentSocketHandler::Receive_SERVER_CONTENT(Packet *p)
{
if (this->curFile == nullptr) {
@@ -476,8 +488,8 @@ bool ClientNetworkContentSocketHandler::Receive_SERVER_CONTENT(Packet *p)
}
} else {
/* We have a file opened, thus are downloading internal content */
- size_t toRead = (size_t)(p->size - p->pos);
- if (fwrite(p->buffer + p->pos, 1, toRead, this->curFile) != toRead) {
+ size_t toRead = p->RemainingBytesToTransfer();
+ if (toRead != 0 && (size_t)p->TransferOut(TransferOutFWrite, this->curFile) != toRead) {
DeleteWindowById(WC_NETWORK_STATUS_WINDOW, WN_NETWORK_STATUS_WINDOW_CONTENT_DOWNLOAD);
ShowErrorMessage(STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD, STR_CONTENT_ERROR_COULD_NOT_DOWNLOAD_FILE_NOT_WRITABLE, WL_ERROR);
this->Close();