TCP fallback tunneling is now working. That hurt more than expected.

This commit is contained in:
Adam Ierymenko 2015-05-22 14:52:23 -07:00
parent cdec05af24
commit 9774f789f2
7 changed files with 181 additions and 154 deletions

View file

@ -25,6 +25,17 @@
* LLC. Start here: http://www.zerotier.com/
*/
// HACK! Will eventually use epoll() or something in Phy<> instead of select().
// Also be sure to change ulimit -n and fs.file-max in /etc/sysctl.conf on relays.
#if defined(__linux__) || defined(__LINUX__) || defined(__LINUX) || defined(LINUX)
#include <linux/posix_types.h>
#include <bits/types.h>
#undef __FD_SETSIZE
#define __FD_SETSIZE 1048576
#undef FD_SETSIZE
#define FD_SETSIZE 1048576
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
@ -41,10 +52,7 @@
#include "../osdep/Phy.hpp"
#define ZT_TCP_PROXY_UDP_POOL_SIZE 1024
#define ZT_TCP_PROXY_UDP_POOL_START_PORT 10000
#define ZT_TCP_PROXY_CONNECTION_TIMEOUT_SECONDS 300
#define ZT_TCP_PROXY_TCP_PORT 443
using namespace ZeroTier;
@ -90,8 +98,7 @@ struct TcpProxyService;
struct TcpProxyService
{
Phy<TcpProxyService *> *phy;
PhySocket *udpPool[ZT_TCP_PROXY_UDP_POOL_SIZE];
int udpPortCounter;
struct Client
{
char tcpReadBuf[131072];
@ -99,99 +106,101 @@ struct TcpProxyService
unsigned long tcpWritePtr;
unsigned long tcpReadPtr;
PhySocket *tcp;
PhySocket *assignedUdp;
PhySocket *udp;
time_t lastActivity;
bool newVersion;
};
std::map< PhySocket *,Client > clients;
struct ReverseMappingKey
PhySocket *getUnusedUdp(void *uptr)
{
uint64_t sourceZTAddress;
PhySocket *sendingUdpSocket;
uint32_t destIp;
unsigned int destPort;
ReverseMappingKey() {}
ReverseMappingKey(uint64_t zt,PhySocket *s,uint32_t ip,unsigned int port) : sourceZTAddress(zt),sendingUdpSocket(s),destIp(ip),destPort(port) {}
inline bool operator<(const ReverseMappingKey &k) const throw() { return (memcmp((const void *)this,(const void *)&k,sizeof(ReverseMappingKey)) < 0); }
inline bool operator==(const ReverseMappingKey &k) const throw() { return (memcmp((const void *)this,(const void *)&k,sizeof(ReverseMappingKey)) == 0); }
};
std::map< ReverseMappingKey,Client * > reverseMappings;
for(int i=0;i<65535;++i) {
++udpPortCounter;
if (udpPortCounter > 0xfffe)
udpPortCounter = 1024;
struct sockaddr_in laddr;
memset(&laddr,0,sizeof(struct sockaddr_in));
laddr.sin_family = AF_INET;
laddr.sin_port = htons((uint16_t)udpPortCounter);
PhySocket *udp = phy->udpBind(reinterpret_cast<struct sockaddr *>(&laddr),uptr);
if (udp)
return udp;
}
return (PhySocket *)0;
}
void phyOnDatagram(PhySocket *sock,void **uptr,const struct sockaddr *from,void *data,unsigned long len)
{
if ((from->sa_family == AF_INET)&&(len > 16)&&(len < 2048)) {
const uint64_t destZt = (
(((uint64_t)(((const unsigned char *)data)[8])) << 32) |
(((uint64_t)(((const unsigned char *)data)[9])) << 24) |
(((uint64_t)(((const unsigned char *)data)[10])) << 16) |
(((uint64_t)(((const unsigned char *)data)[11])) << 8) |
((uint64_t)(((const unsigned char *)data)[12])) );
const uint32_t fromIp = ((const struct sockaddr_in *)from)->sin_addr.s_addr;
const unsigned int fromPort = ntohs(((const struct sockaddr_in *)from)->sin_port);
if (!*uptr)
return;
if ((from->sa_family == AF_INET)&&(len >= 16)&&(len < 2048)) {
Client &c = *((Client *)*uptr);
c.lastActivity = time((time_t *)0);
std::map< ReverseMappingKey,Client * >::iterator rm(reverseMappings.find(ReverseMappingKey(destZt,sock,fromIp,fromPort)));
if (rm != reverseMappings.end()) {
Client &c = *(rm->second);
unsigned long mlen = len;
if (c.newVersion)
mlen += 7; // new clients get IP info
unsigned long mlen = len;
if (c.newVersion)
mlen += 7; // new clients get IP info
if ((c.tcpWritePtr + 5 + mlen) <= sizeof(c.tcpWriteBuf)) {
if (!c.tcpWritePtr)
phy->tcpSetNotifyWritable(c.tcp,true);
if ((c.tcpWritePtr + 5 + mlen) <= sizeof(c.tcpWriteBuf)) {
if (!c.tcpWritePtr)
phy->tcpSetNotifyWritable(c.tcp,true);
c.tcpWriteBuf[c.tcpWritePtr++] = 0x17; // look like TLS data
c.tcpWriteBuf[c.tcpWritePtr++] = 0x03; // look like TLS 1.2
c.tcpWriteBuf[c.tcpWritePtr++] = 0x03; // look like TLS 1.2
c.tcpWriteBuf[c.tcpWritePtr++] = 0x17; // look like TLS data
c.tcpWriteBuf[c.tcpWritePtr++] = 0x03; // look like TLS 1.2
c.tcpWriteBuf[c.tcpWritePtr++] = 0x03; // look like TLS 1.2
c.tcpWriteBuf[c.tcpWritePtr++] = (char)((mlen >> 8) & 0xff);
c.tcpWriteBuf[c.tcpWritePtr++] = (char)(mlen & 0xff);
c.tcpWriteBuf[c.tcpWritePtr++] = (char)((mlen >> 8) & 0xff);
c.tcpWriteBuf[c.tcpWritePtr++] = (char)(mlen & 0xff);
if (c.newVersion) {
c.tcpWriteBuf[c.tcpWritePtr++] = (char)4; // IPv4
*((uint32_t *)(c.tcpWriteBuf + c.tcpWritePtr)) = fromIp;
c.tcpWritePtr += 4;
c.tcpWriteBuf[c.tcpWritePtr++] = (char)((fromPort >> 8) & 0xff);
c.tcpWriteBuf[c.tcpWritePtr++] = (char)(fromPort & 0xff);
}
for(unsigned long i=0;i<len;++i)
c.tcpWriteBuf[c.tcpWritePtr++] = ((const char *)data)[i];
if (c.newVersion) {
c.tcpWriteBuf[c.tcpWritePtr++] = (char)4; // IPv4
*((uint32_t *)(c.tcpWriteBuf + c.tcpWritePtr)) = ((const struct sockaddr_in *)from)->sin_addr.s_addr;
c.tcpWritePtr += 4;
*((uint16_t *)(c.tcpWriteBuf + c.tcpWritePtr)) = ((const struct sockaddr_in *)from)->sin_port;
c.tcpWritePtr += 2;
}
for(unsigned long i=0;i<len;++i)
c.tcpWriteBuf[c.tcpWritePtr++] = ((const char *)data)[i];
}
//printf("<< UDP %s:%d -> %.16llx\n",inet_ntoa(reinterpret_cast<const struct sockaddr_in *>(from)->sin_addr),(int)ntohs(reinterpret_cast<const struct sockaddr_in *>(from)->sin_port),(unsigned long long)&c);
}
}
void phyOnTcpConnect(PhySocket *sock,void **uptr,bool success)
{
// unused, we don't initiate
// unused, we don't initiate outbound connections
}
void phyOnTcpAccept(PhySocket *sockL,PhySocket *sockN,void **uptrL,void **uptrN,const struct sockaddr *from)
{
Client &c = clients[sockN];
PhySocket *udp = getUnusedUdp((void *)&c);
if (!udp) {
phy->close(sockN);
clients.erase(sockN);
//printf("** TCP rejected, no more UDP ports to assign\n");
return;
}
c.tcpWritePtr = 0;
c.tcpReadPtr = 0;
c.tcp = sockN;
c.assignedUdp = udpPool[rand() % ZT_TCP_PROXY_UDP_POOL_SIZE];
c.udp = udp;
c.lastActivity = time((time_t *)0);
c.newVersion = false;
*uptrN = (void *)&c;
//printf("<< TCP from %s -> %.16llx\n",inet_ntoa(reinterpret_cast<const struct sockaddr_in *>(from)->sin_addr),(unsigned long long)&c);
}
void phyOnTcpClose(PhySocket *sock,void **uptr)
{
for(std::map< ReverseMappingKey,Client * >::iterator rm(reverseMappings.begin());rm!=reverseMappings.end();) {
if (rm->second == (Client *)*uptr)
reverseMappings.erase(rm++);
else ++rm;
}
if (!*uptr)
return;
Client &c = *((Client *)*uptr);
phy->close(c.udp);
clients.erase(sock);
//printf("** TCP %.16llx closed\n",(unsigned long long)*uptr);
}
void phyOnTcpData(PhySocket *sock,void **uptr,void *data,unsigned long len)
@ -212,6 +221,7 @@ struct TcpProxyService
if (mlen == 4) {
// Right now just sending this means the client is 'new enough' for the IP header
c.newVersion = true;
//printf("<< TCP %.16llx HELLO\n",(unsigned long long)*uptr);
} else if (mlen >= 7) {
char *payload = c.tcpReadBuf + 5;
unsigned long payloadLen = mlen;
@ -241,22 +251,8 @@ struct TcpProxyService
// Note: we do not relay to privileged ports... just an abuse prevention rule.
if ((ntohs(dest.sin_port) > 1024)&&(payloadLen >= 16)) {
if ((payloadLen >= 28)&&(payload[13] != (char)0xff)) {
// Learn reverse mappings -- we will route replies to these packets
// back to their sending TCP socket. They're on a first come first
// served basis.
const uint64_t sourceZt = (
(((uint64_t)(((const unsigned char *)payload)[13])) << 32) |
(((uint64_t)(((const unsigned char *)payload)[14])) << 24) |
(((uint64_t)(((const unsigned char *)payload)[15])) << 16) |
(((uint64_t)(((const unsigned char *)payload)[16])) << 8) |
((uint64_t)(((const unsigned char *)payload)[17])) );
ReverseMappingKey k(sourceZt,c.assignedUdp,dest.sin_addr.s_addr,ntohl(dest.sin_port));
if (reverseMappings.count(k) == 0)
reverseMappings[k] = &c;
}
phy->udpSend(c.assignedUdp,(const struct sockaddr *)&dest,payload,payloadLen);
phy->udpSend(c.udp,(const struct sockaddr *)&dest,payload,payloadLen);
//printf(">> TCP %.16llx to %s:%d\n",(unsigned long long)*uptr,inet_ntoa(dest.sin_addr),(int)ntohs(dest.sin_port));
}
}
@ -284,11 +280,13 @@ struct TcpProxyService
std::vector<PhySocket *> toClose;
time_t now = time((time_t *)0);
for(std::map< PhySocket *,Client >::iterator c(clients.begin());c!=clients.end();++c) {
if ((now - c->second.lastActivity) >= ZT_TCP_PROXY_CONNECTION_TIMEOUT_SECONDS)
if ((now - c->second.lastActivity) >= ZT_TCP_PROXY_CONNECTION_TIMEOUT_SECONDS) {
toClose.push_back(c->first);
toClose.push_back(c->second.udp);
}
}
for(std::vector<PhySocket *>::iterator s(toClose.begin());s!=toClose.end();++s)
phy->close(*s); // will call phyOnTcpClose() which does cleanup
phy->close(*s);
}
};
@ -299,25 +297,9 @@ int main(int argc,char **argv)
srand(time((time_t *)0));
TcpProxyService svc;
Phy<TcpProxyService *> phy(&svc,true);
Phy<TcpProxyService *> phy(&svc,false);
svc.phy = &phy;
{
int poolSize = 0;
for(unsigned int p=ZT_TCP_PROXY_UDP_POOL_START_PORT;((poolSize<ZT_TCP_PROXY_UDP_POOL_SIZE)&&(p<=65535));++p) {
struct sockaddr_in laddr;
memset(&laddr,0,sizeof(laddr));
laddr.sin_family = AF_INET;
laddr.sin_port = htons((uint16_t)p);
PhySocket *s = phy.udpBind((const struct sockaddr *)&laddr);
if (s)
svc.udpPool[poolSize++] = s;
}
if (poolSize < ZT_TCP_PROXY_UDP_POOL_SIZE) {
fprintf(stderr,"%s: fatal error: cannot bind %d UDP ports\n",argv[0],ZT_TCP_PROXY_UDP_POOL_SIZE);
return 1;
}
}
svc.udpPortCounter = 1023;
{
struct sockaddr_in laddr;