Lots of file splits

.gitignore

@@ -1 +1,2 @@
 mirall
+*.o

Makefile

@@ -1,5 +1,8 @@
-mirall: Makefile mirall.cpp
-	g++ -std=gnu++2a -o mirall mirall.cpp -lgflags -lglog
+mirall: Makefile mirall.o fastcgi.o fastcgi_conn.o buffer.o
+	g++ -std=gnu++2a -o mirall mirall.o fastcgi.o fastcgi_conn.o buffer.o -lgflags -lglog -lpthread
 
 clean:
-	rm --force mirall
+	rm --force mirall *.o
+
+.cpp.o: Makefile *.h
+	g++ -std=gnu++2a -o $@ -c $<

buffer.cpp

@@ -0,0 +1,66 @@
+#include "buffer.h"
+
+ConstBuffer::ConstBuffer(const char *buf, size_t len)
+		: const_buf_(buf),
+		  len_(len) {}
+
+size_t ConstBuffer::ReadMaxLen() const {
+	return len_ - start_;
+}
+
+const char *ConstBuffer::Read(size_t len) {
+	CHECK_LE(len, ReadMaxLen());
+	const auto *ret = &const_buf_[start_];
+	start_ += len;
+	return ret;
+}
+
+bool ConstBuffer::Discard(size_t len) {
+	if (len > ReadMaxLen()) {
+		return false;
+	}
+	Read(len);
+	return true;
+}
+
+void ConstBuffer::ResetRead() {
+	start_ = commit_;
+}
+
+void ConstBuffer::Commit() {
+	commit_ = start_;
+}
+
+
+Buffer::Buffer(char *buf, size_t size, size_t len)
+		: ConstBuffer(buf, size),
+		  buf_(buf),
+		  size_(size) {
+	len_ = len;
+}
+
+Buffer::Buffer(size_t size)
+		: Buffer((own_buf_.reset(new char[size]), own_buf_.get()), size, 0) {}
+
+char *Buffer::WritePtr() {
+	return &buf_[len_];
+}
+
+size_t Buffer::WriteMaxLen() const {
+	return size_ - len_;
+}
+
+void Buffer::Wrote(size_t len) {
+	CHECK_LE(len, WriteMaxLen());
+	len_ += len;
+}
+
+void Buffer::Consume() {
+	if (commit_ == 0) {
+		return;
+	}
+	memmove(buf_, &buf_[commit_], len_ - commit_);
+	len_ -= commit_;
+	start_ -= commit_;
+	commit_ = 0;
+}

buffer.h

@@ -0,0 +1,48 @@
+#pragma once
+
+#include <glog/logging.h>
+#include <memory>
+
+class ConstBuffer {
+  public:
+	ConstBuffer(const char *buf, size_t len);
+
+	size_t ReadMaxLen() const;
+	const char *Read(size_t len);
+	template<class T> const T *ReadObj();
+
+	bool Discard(size_t len); // like Read() but don't use the result
+	void ResetRead(); // next read from last commit
+	void Commit(); // commit read position
+
+  protected:
+	const char *const_buf_;
+	size_t len_;
+	size_t start_ = 0;
+	size_t commit_ = 0;
+};
+
+class Buffer : public ConstBuffer {
+  public:
+  	Buffer(const char *buf, size_t len) = delete;
+	Buffer(char *buf, size_t size, size_t len);
+  	Buffer(size_t size);
+
+	char *WritePtr();
+	size_t WriteMaxLen() const;
+	void Wrote(size_t len);
+
+	void Consume(); // discard up to last commit
+
+  private:
+  	std::unique_ptr<char> own_buf_;
+	char *buf_;
+	const size_t size_;
+};
+
+template<class T> const T *ConstBuffer::ReadObj() {
+	if (ReadMaxLen() < sizeof(T)) {
+		return nullptr;
+	}
+	return reinterpret_cast<const T*>(Read(sizeof(T)));
+}

fastcgi.cpp

@@ -0,0 +1,47 @@
+#include <arpa/inet.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <thread>
+
+#include "fastcgi.h"
+#include "fastcgi_conn.h"
+
+FastCGIServer::FastCGIServer(int port) {
+	LOG(INFO) << "listening on [::1]:" << port;
+
+	listen_sock_ = socket(AF_INET6, SOCK_STREAM, 0);
+	PCHECK(listen_sock_ >= 0) << "socket()";
+
+	{
+		int optval = 1;
+		PCHECK(setsockopt(listen_sock_, SOL_SOCKET, SO_REUSEPORT, &optval, sizeof(optval)) == 0);
+	}
+
+	{
+		sockaddr_in6 bind_addr = {
+			.sin6_family = AF_INET6,
+			.sin6_port = htons(port),
+			.sin6_addr = IN6ADDR_LOOPBACK_INIT,
+		};
+		PCHECK(bind(listen_sock_, (sockaddr*) &bind_addr, sizeof(bind_addr)) == 0);
+	}
+
+	PCHECK(listen(listen_sock_, 128) == 0);
+}
+
+void FastCGIServer::Serve() {
+	while (true) {
+		sockaddr_in6 client_addr;
+		socklen_t client_addr_len = sizeof(client_addr);
+
+		auto client_sock = accept(listen_sock_, (sockaddr*) &client_addr, &client_addr_len);
+		PCHECK(client_sock >= 0) << "accept()";
+		CHECK_EQ(client_addr.sin6_family, AF_INET6);
+
+		auto *conn = new FastCGIConn(client_sock, client_addr);
+		std::thread thread([conn]() { conn->Serve(); });
+		thread.detach();
+	}
+}
+
+

fastcgi.h

@@ -0,0 +1,10 @@
+#pragma once
+
+class FastCGIServer {
+  public:
+  	FastCGIServer(int port);
+	void Serve();
+
+  private:
+	int listen_sock_;
+};

fastcgi_conn.cpp

@@ -0,0 +1,97 @@
+#include <arpa/inet.h>
+#include <netinet/in.h>
+
+#include "fastcgi_conn.h"
+
+namespace {
+
+struct fcgi_header {
+	uint8_t version;
+	uint8_t type;
+  private:
+	uint16_t request_id_; // network byte order
+	uint16_t content_length_; // network byte order
+  public:
+	uint8_t padding_length;
+	uint8_t reserved;
+
+	uint16_t ContentLength() const { return htons(content_length_); }
+};
+
+struct fcgi_begin_request {
+	uint16_t role; // network byte order
+	uint8_t flags;
+	uint8_t reserved[5];
+};
+
+constexpr auto fcgi_max_content_len = 65535;
+constexpr auto fcgi_max_padding_len = 255;
+constexpr auto fcgi_max_record_len = sizeof(fcgi_header) + fcgi_max_content_len + fcgi_max_padding_len;
+
+} // namespace
+
+FastCGIConn::FastCGIConn(int sock, const sockaddr_in6& client_addr)
+		: sock_(sock),
+		  buf_(fcgi_max_record_len) {
+	char client_addr_str[INET6_ADDRSTRLEN];
+	PCHECK(inet_ntop(AF_INET6, &client_addr.sin6_addr, client_addr_str, sizeof(client_addr_str)));
+
+	LOG(INFO) << "new connection: [" << client_addr_str << "]:" << ntohs(client_addr.sin6_port);
+}
+
+FastCGIConn::~FastCGIConn() {
+	PCHECK(close(sock_) == 0);
+	LOG(INFO) << "connection closed";
+}
+
+void FastCGIConn::Serve() {
+	while (true) {
+		auto read_len = read(sock_, buf_.WritePtr(), buf_.WriteMaxLen());
+		PCHECK(read_len >= 0);
+		if (read_len == 0) {
+			LOG(INFO) << "peer closed connection";
+		}
+		buf_.Wrote(read_len);
+
+		ParseBuf();
+		buf_.Consume(); // free buffer tail space for next read
+	}
+}
+
+void FastCGIConn::ParseBuf() {
+	buf_.ResetRead();
+
+	while (true) {
+		const auto *header = buf_.ReadObj<fcgi_header>();
+		if (!header) {
+			return;
+		}
+
+		CHECK_EQ(header->version, 1);
+		if (buf_.ReadMaxLen() < header->ContentLength() + header->padding_length) {
+			return;
+		}
+
+		LOG(INFO) << "type: " << (int)header->type;
+
+		switch (header->type) {
+		  case 1:
+		  	{
+				CHECK_EQ(header->ContentLength(), sizeof(fcgi_begin_request));
+				const auto *begin_request = CHECK_NOTNULL(buf_.ReadObj<fcgi_begin_request>());
+				CHECK_EQ(ntohs(begin_request->role), 1);
+			}
+			break;
+
+		  case 4:
+		    {
+				const auto *params = buf_.Read(header->ContentLength());
+			}
+			break;
+		}
+
+		CHECK(buf_.Discard(header->padding_length));
+
+		buf_.Commit(); // we've acted on the bytes read so far
+	}
+}

fastcgi_conn.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include "buffer.h"
+
+struct sockaddr_in6;
+
+class FastCGIConn {
+  public:
+	FastCGIConn(int sock, const sockaddr_in6& client_addr);
+	~FastCGIConn();
+
+	void Serve();
+
+  private:
+  	void ParseBuf();
+
+  	const int sock_;
+	Buffer buf_;
+};

mirall.cpp

@@ -1,8 +1,7 @@
-#include <arpa/inet.h>
 #include <gflags/gflags.h>
 #include <glog/logging.h>
-#include <netinet/in.h>
-#include <sys/socket.h>
+
+#include "fastcgi.h"
 
 DEFINE_int32(port, 9000, "TCP port to bind");
 
@@ -10,30 +9,6 @@ int main(int argc, char *argv[]) {
 	google::InitGoogleLogging(argv[0]);
 	gflags::ParseCommandLineFlags(&argc, &argv, true);
 
-	auto listen_sock = socket(AF_INET6, SOCK_STREAM, 0);
-	PCHECK(listen_sock >= 0) << "socket()";
-
-	sockaddr_in6 bind_addr = {
-		.sin6_family = AF_INET6,
-		.sin6_port = htons(FLAGS_port),
-		.sin6_addr = IN6ADDR_LOOPBACK_INIT,
-	};
-	PCHECK(bind(listen_sock, (sockaddr*) &bind_addr, sizeof(bind_addr)) == 0);
-
-	PCHECK(listen(listen_sock, 128) == 0);
-
-	while (true) {
-		sockaddr_in6 client_addr;
-		socklen_t client_addr_len = sizeof(client_addr);
-
-		auto sock = accept(listen_sock, (sockaddr*) &client_addr, &client_addr_len);
-		PCHECK(sock >= 0) << "accept()";
-
-		CHECK_EQ(client_addr.sin6_family, AF_INET6);
-
-		char client_addr_str[INET6_ADDRSTRLEN];
-		PCHECK(inet_ntop(AF_INET6, &client_addr.sin6_addr, client_addr_str, sizeof(client_addr_str)));
-
-		LOG(INFO) << "new connection: [" << client_addr_str << "]:" << ntohs(client_addr.sin6_port);
-	}
+	FastCGIServer server(FLAGS_port);
+	server.Serve();
 }