From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sat, 7 Feb 2015 00:11:37 +0000 (+0100)
Subject: Move GREProtocol into its own files, and Reorderer into a .h file.
X-Git-Url: https://git.sesse.net/?p=greproxy;a=commitdiff_plain;h=7c67b21504e7758f4148386befc8cd80455a1a85

Move GREProtocol into its own files, and Reorderer into a .h file.
---

diff --git a/greprotocol.cpp b/greprotocol.cpp
new file mode 100644
index 0000000..b826a52
--- /dev/null
+++ b/greprotocol.cpp
@@ -0,0 +1,112 @@
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "greprotocol.h"
+#include "reorderer.h"
+
+using namespace std;
+
+struct gre_header {
+	uint8_t reserved0_hi : 4;
+	uint8_t has_seq : 1;
+	uint8_t has_key : 1;
+	uint8_t unused : 1;
+	uint8_t has_checksum : 1;
+
+	uint8_t version : 3;
+	uint8_t reserved0_lo: 5;
+
+	uint16_t protocol_type;
+};
+
+
+GREProtocol::GREProtocol(const in6_addr &src, const in6_addr &dst)
+	: seq(0)
+{
+	memset(&dstaddr, 0, sizeof(dstaddr));
+	dstaddr.sin6_family = AF_INET6;
+	dstaddr.sin6_addr = dst;
+
+	sock = socket(AF_INET6, SOCK_RAW, IPPROTO_GRE);
+	if (sock == -1) {
+		perror("socket");
+		exit(1);
+	}
+
+	sockaddr_in6 my_addr;
+	memset(&my_addr, 0, sizeof(my_addr));
+	my_addr.sin6_family = AF_INET6;
+	my_addr.sin6_addr = src;
+	if (::bind(sock, (sockaddr *)&my_addr, sizeof(my_addr)) == -1) {
+		perror("bind");
+		exit(1);
+	}
+}
+
+void GREProtocol::send_packet(uint16_t proto, const string &data)
+{
+	char buf[4096];
+	gre_header *gre = (gre_header *)buf;
+
+	memset(gre, 0, sizeof(*gre));
+	gre->has_seq = 1;
+	gre->version = 0;
+	gre->protocol_type = htons(proto);
+
+	char *ptr = buf + sizeof(*gre);
+	int seq_be = htonl(seq++);
+	memcpy(ptr, &seq_be, sizeof(seq_be));
+	ptr += sizeof(seq_be);
+
+	memcpy(ptr, data.data(), data.size());
+	
+	if (sendto(sock, buf, data.size() + sizeof(seq_be) + sizeof(*gre), 0, (sockaddr *)&dstaddr, sizeof(dstaddr)) == -1) {
+		perror("sendto");
+		return;
+	}
+}
+
+int GREProtocol::fd() const
+{
+	return sock;
+}
+
+void GREProtocol::read_packet(Reorderer *sender)
+{
+	struct sockaddr_storage addr;
+	socklen_t addrlen = sizeof(addr);
+	char buf[4096];
+	int ret = recvfrom(sock, buf, sizeof(buf), 0, (struct sockaddr *)&addr, &addrlen);
+	if (ret == -1) {
+		perror("recvfrom");
+		exit(1);
+	}
+	if (addr.ss_family != AF_INET6) {
+		return;
+	}
+	struct in6_addr *addr6 = &((struct sockaddr_in6 *)&addr)->sin6_addr;
+	if (memcmp(addr6, &dstaddr.sin6_addr, sizeof(*addr6)) != 0) {
+		// ignore
+		return;
+	}
+	gre_header* gre = (gre_header *)buf;
+
+	char* ptr = buf + sizeof(gre_header);
+	if (gre->has_checksum) {
+		ptr += 4;
+	}
+	if (gre->has_key) {
+		ptr += 4;
+	}
+	uint32_t seq;
+	if (gre->has_seq) {
+		seq = ntohl(*(uint32_t *)ptr);
+		ptr += 4;
+	}
+
+	//printf("gre packet: proto=%x\n", ntohs(gre->protocol_type));
+
+	sender->handle_packet(ntohs(gre->protocol_type), string(ptr, buf + ret), seq);
+}
+
diff --git a/greprotocol.h b/greprotocol.h
new file mode 100644
index 0000000..6930f20
--- /dev/null
+++ b/greprotocol.h
@@ -0,0 +1,25 @@
+#ifndef _GREPROTOCOL_H
+#define _GREPROTOCOL_H
+
+#include "protocol.h"
+
+#include <arpa/inet.h>
+#include <stdint.h>
+#include <string>
+
+class Reorderer;
+
+class GREProtocol : public Protocol {
+public:
+	GREProtocol(const in6_addr &myaddr, const in6_addr &dst);
+	virtual void send_packet(uint16_t proto, const std::string &data);
+	virtual int fd() const;
+	void read_packet(Reorderer* sender);
+
+private:
+	int seq;
+	int sock;
+	sockaddr_in6 dstaddr;
+};
+
+#endif  // !defined(_GREPROTOCOL_H)
diff --git a/reorderer.h b/reorderer.h
new file mode 100644
index 0000000..476093f
--- /dev/null
+++ b/reorderer.h
@@ -0,0 +1,39 @@
+#ifndef _REORDERER_H
+#define _REORDERER_H 1
+
+#include <stdint.h>
+
+#include <algorithm>
+#include <map>
+#include <queue>
+#include <string>
+#include <vector>
+
+class Protocol;
+
+struct GREPacket {
+	int seq;
+	uint16_t proto;
+	std::string data;
+
+	bool operator> (const GREPacket &other) const {
+		return seq > other.seq;
+	}
+};
+
+class Reorderer {
+public:
+	Reorderer(Protocol* sender);
+	void handle_packet(uint16_t proto, const std::string& data, int seq);
+
+private:
+	void send_packet(uint16_t proto, const std::string &data, bool silence);
+
+	Protocol* sender;
+	int last_seq;
+
+	std::priority_queue<GREPacket, std::vector<GREPacket>, std::greater<GREPacket>> packet_buffer;
+	std::map<int, int> ccs;
+};
+
+#endif  // !defined(_REORDERER_H)