ZeroTierOne/osdep/ExtOsdep.cpp
2025-02-26 10:27:23 -08:00

534 lines
18 KiB
C++

#include <sys/times.h>
#include <fcntl.h>
#include <unistd.h>
#include <iostream>
#include "ExtOsdep.hpp"
#include <list>
#include "../node/AtomicCounter.hpp"
#define ZT_TAP_BUF_SIZE 16384
namespace ZeroTier {
static int eodFd = -1;
static Mutex eodMutex;
static int eodMgmtFd = -1;
struct EodRoute {
InetAddress target;
InetAddress via;
InetAddress src;
std::string ifname;
};
static std::list<EodRoute> allRoutes;
template<typename T> static void __eodSend(const T &t) {
write(eodFd, &t, sizeof(t));
}
static void strncpyx(char *dest, const char *src, size_t n) {
strncpy(dest, src, n);
if (n > 1) dest[n - 1] = 0;
}
static int __eodWait(unsigned char msg, unsigned char *d, unsigned l,
unsigned maxl = 0, int *recvfd = nullptr) {
if (!maxl) maxl = l;
auto start = times(NULL);
while (1) {
msghdr mh;
iovec iov;
struct {
size_t cmsg_len;
int cmsg_level;
int cmsg_type;
int fd;
} __attribute__((packed)) cmsg;
memset(&mh, 0, sizeof(mh));
mh.msg_iov = &iov;
mh.msg_iovlen = 1;
if (recvfd) {
mh.msg_control = &cmsg;
mh.msg_controllen = sizeof(cmsg);
}
iov.iov_base = d;
iov.iov_len = maxl;
int r = recvmsg(eodFd, &mh, MSG_TRUNC | MSG_CMSG_CLOEXEC);
if (r > 0) {
if (recvfd && mh.msg_controllen >= sizeof(cmsg)
&& cmsg.cmsg_len == sizeof(cmsg)
&& cmsg.cmsg_level == SOL_SOCKET
&& cmsg.cmsg_type == SCM_RIGHTS) {
*recvfd = cmsg.fd;
fprintf(stderr, "eodWait: received fd %d\n", *recvfd);
}
if (d[0] != msg) {
fprintf(stderr, "eodWait: wrong msg, expected %u got %u\n", msg, d[0]);
return -1;
}
if ((unsigned)r < l || (unsigned)r > maxl) {
fprintf(stderr, "eodWait: wrong len, expected %u got %d\n", l, r);
return -1;
}
return r;
}
if (times(NULL) - start > 500) {
fprintf(stderr, "eodWait: timeout\n");
return -1;
}
usleep(100000);
}
}
template<typename T> static bool __eodWait(unsigned msg, T &t) {
return __eodWait(msg, (unsigned char *)&t, sizeof(T)) == (int)sizeof(T);
}
template<typename M, typename R> static bool __eodXchg(const M &m, unsigned rm, R &r) {
__eodSend(m);
return __eodWait(rm, r);
}
template<typename M, typename R> static bool eodXchg(const M &m, unsigned rm, R &r) {
Mutex::Lock l(eodMutex);
return __eodXchg(m, rm, r);
}
void ExtOsdep::init(int fd1, int fd2) {
eodFd = fd1;
eodMgmtFd = fd2;
fcntl(eodMgmtFd,F_SETFL,O_NONBLOCK);
}
void ExtOsdep::started(int *f, void **cp) {
*f = eodMgmtFd;
*cp = (void *)eodMgmtFd;
unsigned char msg = ZT_EOD_MSG_STARTED;
Mutex::Lock l(eodMutex);
__eodSend(msg);
}
static std::string mgmtrd;
static std::string mgmtwr;
bool ExtOsdep::mgmtWritable(void *cookie) {
if (cookie != (void *)eodMgmtFd) return false;
if (mgmtwr.size() == 0) return true;
auto sz = write(eodMgmtFd, mgmtwr.data(), mgmtwr.size());
if (sz <= 0) return false;
mgmtwr.erase(mgmtwr.begin(), mgmtwr.begin() + sz);
return mgmtwr.empty();
}
bool ExtOsdep::mgmtRecv(void *cookie, void *data, unsigned long len,
std::function<unsigned (unsigned, const std::string &, const std::string &, std::string &)> cb) {
if (cookie != (void *)eodMgmtFd) return false;
mgmtrd.append((char *)data, len);
while (1) {
auto req = (zt_eod_mgmt_req *)mgmtrd.data();
if (mgmtrd.size() < sizeof(*req)) break;
unsigned reqsz = sizeof(*req) + req->pathlen + req->datalen;
if (mgmtrd.size() < reqsz) break;
std::string resp;
char *p = (char *)req->data;
zt_eod_mgmt_reply rep;
rep.scode = cb(req->method, std::string(p, p + req->pathlen),
std::string(p + req->pathlen, p + req->pathlen + req->datalen), resp);
rep.datalen = resp.size();
mgmtrd.erase(mgmtrd.begin(), mgmtrd.begin() + reqsz);
mgmtwr.append((char *)&rep, sizeof(rep));
mgmtwr.append(resp);
auto sz = write(eodMgmtFd, mgmtwr.data(), mgmtwr.size());
if (sz > 0) mgmtwr.erase(mgmtwr.begin(), mgmtwr.begin() + sz);
}
return !mgmtwr.empty();
}
void ExtOsdep::routeAddDel(bool add, const InetAddress &target, const InetAddress &via, const InetAddress &src, const char *ifname) {
Mutex::Lock l(eodMutex);
std::string ifn;
if (ifname) ifn = ifname;
if (add) {
for (auto x = allRoutes.begin(); x != allRoutes.end(); ++x) {
if (x->target == target && x->via == via
&& x->src == src && x->ifname == ifn) return;
}
allRoutes.push_back({target, via, src, ifn});
}
else {
bool found = false;
for (auto x = allRoutes.begin(); x != allRoutes.end(); ++x) {
if (x->target == target && x->via == via
&& x->src == src && x->ifname == ifn) {
allRoutes.erase(x);
found = true;
break;
}
}
if (!found) return;
}
zt_eod_msg_route req;
memset(&req, 0, sizeof(req));
req.cmd = add ? ZT_EOD_MSG_ADDROUTE : ZT_EOD_MSG_DELROUTE;
req.afi = target.isV4() ? 1 : 2;
req.dstlen = target.netmaskBits();
memcpy(req.dst, target.rawIpData(), target.isV4() ? 4 : 16);
if (ifname) strncpyx(req.dev, ifname, sizeof(req.dev));
if (via) memcpy(req.gw, via.rawIpData(), target.isV4() ? 4 : 16);
if (src) memcpy(req.src, src.rawIpData(), target.isV4() ? 4 : 16);
unsigned char resp;
__eodXchg(req, add ? ZT_EOD_MSG_ADDROUTERESP : ZT_EOD_MSG_DELROUTERESP, resp);
}
bool ExtOsdep::getBindAddrs(std::map<InetAddress,std::string> &ret) {
Mutex::Lock l(eodMutex);
unsigned char req = ZT_EOD_MSG_GETBINDADDRS;
__eodSend(req);
zt_eod_msg_getbindaddrsresp *resp;
unsigned char buf[ZT_EOD_MAXMSGSIZE];
int r = __eodWait(ZT_EOD_MSG_GETBINDADDRSRESP, (unsigned char *)buf, sizeof(*resp), sizeof(buf));
if (r < (int)sizeof(*resp)) return false;
int c = (r - (int)sizeof(*resp)) / sizeof(resp->addrs[0]);
resp = (zt_eod_msg_getbindaddrsresp *)buf;
for (int i = 0; i < c; ++i) {
ret[InetAddress(resp->addrs[i].data, resp->addrs[i].afi == 1 ? 4 : 16, resp->addrs[i].len)]
= resp->addrs[i].ifname;
}
return resp->result;
}
ExtOsdepTap::ExtOsdepTap(
const char *homePath,
const MAC &mac,
unsigned int mtu,
unsigned int metric,
uint64_t nwid,
const char *friendlyName,
void (*handler)(void *,void *,uint64_t,const MAC &,const MAC &,unsigned int,unsigned int,const void *,unsigned int),
void *arg) :
_handler(handler),
_arg(arg),
_nwid(nwid),
_mac(mac),
_homePath(homePath),
_mtu(mtu),
_fd(0),
_enabled(true),
_run(true)
{
zt_eod_msg_addtap req;
req.cmd = ZT_EOD_MSG_ADDTAP;
req.nwid = nwid;
req.mtu = mtu;
req.metric = metric;
strncpyx(req.fname, friendlyName, sizeof(req.fname));
mac.copyTo(req.mac, 6);
zt_eod_msg_addtapresp resp;
Mutex::Lock l(eodMutex);
__eodSend(req);
_fd = -1;
if (__eodWait(ZT_EOD_MSG_ADDTAPRESP, (unsigned char *)&resp, sizeof(resp), sizeof(resp), &_fd) != sizeof(resp))
throw std::runtime_error(std::string("could not create TAP"));
_dev = resp.name;
if (_dev.empty() || _fd < 0)
throw std::runtime_error(std::string("could not create TAP"));
fcntl(_fd,F_SETFL,O_NONBLOCK);
// processing shamelessly copied from LinuxEthernetTap
(void)::pipe(_shutdownSignalPipe);
for(unsigned int t=0;t<2;++t) {
_tapReaderThread[t] = std::thread([this, t]{
fd_set readfds,nullfds;
int n,nfds,r;
void *buf = nullptr;
std::vector<void *> buffers;
if (!_run)
return;
FD_ZERO(&readfds);
FD_ZERO(&nullfds);
nfds = (int)std::max(_shutdownSignalPipe[0],_fd) + 1;
r = 0;
for(;;) {
FD_SET(_shutdownSignalPipe[0],&readfds);
FD_SET(_fd,&readfds);
select(nfds,&readfds,&nullfds,&nullfds,(struct timeval *)0);
if (FD_ISSET(_shutdownSignalPipe[0],&readfds)) // writes to shutdown pipe terminate thread
break;
if (FD_ISSET(_fd,&readfds)) {
for(;;) { // read until there are no more packets, then return to outer select() loop
if (!buf) {
// To reduce use of the mutex, we keep a local buffer vector and
// swap (which is a pointer swap) with the global one when it's
// empty. This retrieves a batch of buffers to use.
if (buffers.empty()) {
std::lock_guard<std::mutex> l(_buffers_l);
buffers.swap(_buffers);
}
if (buffers.empty()) {
buf = malloc(ZT_TAP_BUF_SIZE);
if (!buf)
break;
} else {
buf = buffers.back();
buffers.pop_back();
}
}
n = (int)::read(_fd,reinterpret_cast<uint8_t *>(buf) + r,ZT_TAP_BUF_SIZE - r);
if (n > 0) {
// Some tap drivers like to send the ethernet frame and the
// payload in two chunks, so handle that by accumulating
// data until we have at least a frame.
r += n;
if (r > 14) {
if (r > ((int)_mtu + 14)) // sanity check for weird TAP behavior on some platforms
r = _mtu + 14;
if (_enabled && _tapqsize.load() < 1000) {
++_tapqsize;
_tapq.post(std::pair<void *,int>(buf,r));
buf = nullptr;
}
r = 0;
}
} else {
r = 0;
break;
}
}
}
}
});
}
_tapProcessorThread = std::thread([this] {
MAC to,from;
std::pair<void *,int> qi;
while (_tapq.get(qi)) {
--_tapqsize;
uint8_t *const b = reinterpret_cast<uint8_t *>(qi.first);
if (b) {
to.setTo(b, 6);
from.setTo(b + 6, 6);
unsigned int etherType = Utils::ntoh(((const uint16_t *)b)[6]);
_handler(_arg, nullptr, _nwid, from, to, etherType, 0, (const void *)(b + 14),(unsigned int)(qi.second - 14));
{
std::lock_guard<std::mutex> l(_buffers_l);
if (_buffers.size() < 128)
_buffers.push_back(qi.first);
else free(qi.first);
}
} else break;
}
});
}
ExtOsdepTap::~ExtOsdepTap() {
_run = false;
(void)::write(_shutdownSignalPipe[1],"\0",1); // causes reader thread(s) to exit
_tapq.post(std::pair<void *,int>(nullptr,0)); // causes processor thread to exit
_tapReaderThread[0].join();
_tapReaderThread[1].join();
_tapProcessorThread.join();
::close(_fd);
::close(_shutdownSignalPipe[0]);
::close(_shutdownSignalPipe[1]);
for(std::vector<void *>::iterator i(_buffers.begin());i!=_buffers.end();++i)
free(*i);
std::vector< std::pair<void *,int> > dv(_tapq.drain());
for(std::vector< std::pair<void *,int> >::iterator i(dv.begin());i!=dv.end();++i) {
if (i->first)
free(i->first);
}
zt_eod_msg_deltap req;
req.cmd = ZT_EOD_MSG_DELTAP;
strcpy(req.name, _dev.c_str());
unsigned char resp;
eodXchg(req, ZT_EOD_MSG_DELTAPRESP, resp);
}
void ExtOsdepTap::setEnabled(bool en) {
_enabled = en;
}
bool ExtOsdepTap::enabled() const {
return _enabled;
}
void ExtOsdepTap::doRemoveIp(const InetAddress &ip) {
zt_eod_msg_ip req;
req.cmd = ZT_EOD_MSG_DELIP;
strcpy(req.name, _dev.c_str());
req.afi = ip.isV4() ? 1 : 2;
req.len = ip.netmaskBits();
memcpy(req.data, ip.rawIpData(), ip.isV4() ? 4 : 16);
unsigned char resp;
__eodXchg(req, ZT_EOD_MSG_DELIPRESP, resp);
}
bool ExtOsdepTap::addIp(const InetAddress &ip) {
Mutex::Lock l(eodMutex);
for(auto i = allIps.begin();i!=allIps.end();++i) {
if (*i == ip) return true;
if (i->ipsEqual(ip)) doRemoveIp(*i);
}
zt_eod_msg_ip req;
req.cmd = ZT_EOD_MSG_ADDIP;
strcpy(req.name, _dev.c_str());
req.afi = ip.isV4() ? 1 : 2;
req.len = ip.netmaskBits();
memcpy(req.data, ip.rawIpData(), ip.isV4() ? 4 : 16);
unsigned char resp;
__eodXchg(req, ZT_EOD_MSG_ADDIPRESP, resp);
allIps.push_back(ip);
return true;
}
bool ExtOsdepTap::addIps(std::vector<InetAddress> ips) {
return false;
}
bool ExtOsdepTap::removeIp(const InetAddress &ip) {
Mutex::Lock l(eodMutex);
for(auto i = allIps.begin();i!=allIps.end();++i) {
if (*i == ip) {
doRemoveIp(*i);
return true;
}
}
return false;
}
std::vector<InetAddress> ExtOsdepTap::ips() const {
std::vector<InetAddress> ret;
Mutex::Lock l(eodMutex);
zt_eod_msg_getips req;
req.cmd = ZT_EOD_MSG_GETIPS;
strcpy(req.name, _dev.c_str());
__eodSend(req);
zt_eod_msg_getipsresp *resp;
unsigned char buf[ZT_EOD_MAXMSGSIZE];
int r = __eodWait(ZT_EOD_MSG_GETIPSRESP, (unsigned char *)buf, sizeof(*resp), sizeof(buf));
if (r < (int)sizeof(*resp)) return ret;
int c = (r - (int)sizeof(*resp)) / sizeof(resp->addrs[0]);
resp = (zt_eod_msg_getipsresp *)buf;
for (int i = 0; i < c; ++i) {
ret.push_back(InetAddress(resp->addrs[i].data, resp->addrs[i].afi == 1 ? 4 : 16, resp->addrs[i].len));
}
return ret;
}
void ExtOsdepTap::put(const MAC &from,const MAC &to,unsigned int etherType,const void *data,unsigned int len) {
char putBuf[ZT_MAX_MTU + 64];
if ((_fd > 0)&&(len <= _mtu)&&(_enabled)) {
to.copyTo(putBuf,6);
from.copyTo(putBuf + 6,6);
*((uint16_t *)(putBuf + 12)) = htons((uint16_t)etherType);
memcpy(putBuf + 14,data,len);
len += 14;
(void)::write(_fd,putBuf,len);
}
}
std::string ExtOsdepTap::deviceName() const {
return _dev;
}
void ExtOsdepTap::setFriendlyName(const char *friendlyName) {}
void ExtOsdepTap::scanMulticastGroups(std::vector<MulticastGroup> &added,std::vector<MulticastGroup> &removed) {
char *ptr,*ptr2;
unsigned char mac[6];
std::vector<MulticastGroup> newGroups;
int fd = ::open("/proc/net/dev_mcast",O_RDONLY);
if (fd > 0) {
char buf[131072];
int n = (int)::read(fd,buf,sizeof(buf));
if ((n > 0)&&(n < (int)sizeof(buf))) {
buf[n] = (char)0;
for(char *l=strtok_r(buf,"\r\n",&ptr);(l);l=strtok_r((char *)0,"\r\n",&ptr)) {
int fno = 0;
char *devname = (char *)0;
char *mcastmac = (char *)0;
for(char *f=strtok_r(l," \t",&ptr2);(f);f=strtok_r((char *)0," \t",&ptr2)) {
if (fno == 1)
devname = f;
else if (fno == 4)
mcastmac = f;
++fno;
}
if ((devname)&&(!strcmp(devname,_dev.c_str()))&&(mcastmac)&&(Utils::unhex(mcastmac,mac,6) == 6))
newGroups.push_back(MulticastGroup(MAC(mac,6),0));
}
}
::close(fd);
}
std::vector<InetAddress> allIps(ips());
for(std::vector<InetAddress>::iterator ip(allIps.begin());ip!=allIps.end();++ip)
newGroups.push_back(MulticastGroup::deriveMulticastGroupForAddressResolution(*ip));
std::sort(newGroups.begin(),newGroups.end());
newGroups.erase(std::unique(newGroups.begin(),newGroups.end()),newGroups.end());
for(std::vector<MulticastGroup>::iterator m(newGroups.begin());m!=newGroups.end();++m) {
if (!std::binary_search(_multicastGroups.begin(),_multicastGroups.end(),*m))
added.push_back(*m);
}
for(std::vector<MulticastGroup>::iterator m(_multicastGroups.begin());m!=_multicastGroups.end();++m) {
if (!std::binary_search(newGroups.begin(),newGroups.end(),*m))
removed.push_back(*m);
}
_multicastGroups.swap(newGroups);
}
void ExtOsdepTap::setMtu(unsigned int mtu) {
if (mtu == _mtu) return;
_mtu = mtu;
zt_eod_msg_setmtu req;
req.cmd = ZT_EOD_MSG_SETMTU;
strcpy(req.name, _dev.c_str());
req.mtu = mtu;
unsigned char resp;
eodXchg(req, ZT_EOD_MSG_SETMTURESP, resp);
}
} // namespace ZeroTier