Move to canonical device naming on Linux.

This commit is contained in:
Adam Ierymenko 2017-05-19 15:18:47 -07:00
parent 99e2098a48
commit 92289c1981

View File

@ -64,6 +64,19 @@ namespace ZeroTier {
static Mutex __tapCreateLock;
static const char _base32_chars[32] = { 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','2','3','4','5','6','7' };
static void _base32_5_to_8(const uint8_t *in,char *out)
{
out[0] = _base32_chars[(in[0]) >> 3];
out[1] = _base32_chars[(in[0] & 0x07) << 2 | (in[1] & 0xc0) >> 6];
out[2] = _base32_chars[(in[1] & 0x3e) >> 1];
out[3] = _base32_chars[(in[1] & 0x01) << 4 | (in[2] & 0xf0) >> 4];
out[4] = _base32_chars[(in[2] & 0x0f) << 1 | (in[3] & 0x80) >> 7];
out[5] = _base32_chars[(in[3] & 0x7c) >> 2];
out[6] = _base32_chars[(in[3] & 0x03) << 3 | (in[4] & 0xe0) >> 5];
out[7] = _base32_chars[(in[4] & 0x1f)];
}
LinuxEthernetTap::LinuxEthernetTap(
const char *homePath,
const MAC &mac,
@ -98,23 +111,7 @@ LinuxEthernetTap::LinuxEthernetTap(
struct ifreq ifr;
memset(&ifr,0,sizeof(ifr));
// Linux supports arbitrary device naming -- this isn't available on other platforms so just use a simple hack for it
#ifdef __SYNOLOGY__
int devno = 50;
#else
int devno = 0;
#endif
std::string devicepfx;
OSUtils::readFile((_homePath + ZT_PATH_SEPARATOR_S + "devicepfx").c_str(),devicepfx);
if (devicepfx.length() == 0) {
#ifdef __SYNOLOGY__
devicepfx = "eth";
#else
devicepfx = "zt";
#endif
}
// Try to recall our last device name, or pick an unused one if that fails.
// Restore device names from legacy devicemap, but for new devices we use a base32-based canonical naming
std::map<std::string,std::string> globalDeviceMap;
FILE *devmapf = fopen((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),"r");
if (devmapf) {
@ -140,11 +137,30 @@ LinuxEthernetTap::LinuxEthernetTap(
Utils::snprintf(procpath,sizeof(procpath),"/proc/sys/net/ipv4/conf/%s",ifr.ifr_name);
recalledDevice = (stat(procpath,&sbuf) != 0);
}
if (!recalledDevice) {
#ifdef __SYNOLOGY__
int devno = 50;
do {
Utils::snprintf(ifr.ifr_name,sizeof(ifr.ifr_name),"%s%d",devicepfx.c_str(),devno++);
Utils::snprintf(ifr.ifr_name,sizeof(ifr.ifr_name),"eth%d",devno++);
Utils::snprintf(procpath,sizeof(procpath),"/proc/sys/net/ipv4/conf/%s",ifr.ifr_name);
} while (stat(procpath,&sbuf) == 0); // try zt#++ until we find one that does not exist
#else
char devno = 0;
do {
uint64_t tmp2[2];
tmp2[0] = Utils::hton(nwid);
tmp2[1] = 0;
char tmp3[17];
tmp3[0] = 'z';
tmp3[1] = 't' + (devno++);
_base32_5_to_8(reinterpret_cast<const uint8_t *>(tmp2),tmp3 + 2);
_base32_5_to_8(reinterpret_cast<const uint8_t *>(tmp2) + 5,tmp3 + 10);
tmp3[15] = (char)0;
memcpy(ifr.ifr_name,tmp3,16);
Utils::snprintf(procpath,sizeof(procpath),"/proc/sys/net/ipv4/conf/%s",ifr.ifr_name);
} while (stat(procpath,&sbuf) == 0);
#endif
}
ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
@ -207,6 +223,7 @@ LinuxEthernetTap::LinuxEthernetTap(
(void)::pipe(_shutdownSignalPipe);
/*
globalDeviceMap[nwids] = _dev;
devmapf = fopen((_homePath + ZT_PATH_SEPARATOR_S + "devicemap").c_str(),"w");
if (devmapf) {
@ -217,6 +234,7 @@ LinuxEthernetTap::LinuxEthernetTap(
}
fclose(devmapf);
}
*/
_thread = Thread::start(this);
}