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better GUID

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This commit is contained in:
Michael Davidsaver
2019-12-18 20:55:29 -08:00
parent 87c10d2c15
commit 787ad4841f
1 changed files with 58 additions and 39 deletions
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src/server.cpp
+58 -39
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@@ -4,6 +4,13 @@
* in file LICENSE that is included with this distribution.
*/
#if defined(_WIN32)
# include <windows.h>
#elif !defined(__rtems__) && !defined(vxWorks)
# include <sys/types.h>
# include <unistd.h>
#endif
#include <list>
#include <map>
#include <regex>
@@ -296,45 +303,6 @@ Server::Pvt::Pvt(Config&& conf)
evsocket dummy(AF_INET, SOCK_DGRAM, 0);
{
// choose new GUID.
// treat as 3x 32-bit unsigned.
union {
std::array<uint32_t, 3> i;
std::array<uint8_t, 3*4> b;
} pun;
static_assert (sizeof(pun)==12, "");
// i[0] time
epicsTimeStamp now;
epicsTimeGetCurrent(&now);
pun.i[0] = now.secPastEpoch ^ now.nsec;
// i[1] host
// mix together all local bcast addresses
pun.i[1] = 0xdeadbeef; // because... why not
{
ELLLIST bcasts = ELLLIST_INIT;
osiSockAddr match;
match.ia.sin_family = AF_INET;
match.ia.sin_addr.s_addr = htonl(INADDR_ANY);
match.ia.sin_port = 0;
osiSockDiscoverBroadcastAddresses(&bcasts, dummy.sock, &match);
while(ELLNODE *cur = ellGet(&bcasts)) {
osiSockAddrNode *node = CONTAINER(cur, osiSockAddrNode, node);
if(node->addr.sa.sa_family==AF_INET)
pun.i[1] ^= ntohl(node->addr.ia.sin_addr.s_addr);
free(cur);
}
}
// i[2] random
pun.i[2] = (rand()/double(RAND_MAX))*0xffffffff;
std::copy(pun.b.begin(), pun.b.end(), effective.guid.begin());
}
acceptor_loop.call([this, &dummy](){
// from acceptor worker
@@ -391,6 +359,57 @@ Server::Pvt::Pvt(Config&& conf)
effective.auto_beacon = false;
});
{
// choose new GUID.
// treat as 3x 32-bit unsigned.
union {
std::array<uint32_t, 3> i;
std::array<uint8_t, 3*4> b;
} pun;
static_assert (sizeof(pun)==12, "");
// i[0] (start) time
epicsTimeStamp now;
epicsTimeGetCurrent(&now);
pun.i[0] = now.secPastEpoch ^ now.nsec;
// i[1] host
// mix together all local bcast addresses
pun.i[1] = 0xdeadbeef; // because... why not
{
ELLLIST bcasts = ELLLIST_INIT;
osiSockAddr match;
match.ia.sin_family = AF_INET;
match.ia.sin_addr.s_addr = htonl(INADDR_ANY);
match.ia.sin_port = 0;
osiSockDiscoverBroadcastAddresses(&bcasts, dummy.sock, &match);
while(ELLNODE *cur = ellGet(&bcasts)) {
osiSockAddrNode *node = CONTAINER(cur, osiSockAddrNode, node);
if(node->addr.sa.sa_family==AF_INET)
pun.i[1] ^= ntohl(node->addr.ia.sin_addr.s_addr);
free(cur);
}
}
// i[2] process on host
#if defined(_WIN32)
pun.i[2] = GetCurrentProcessId();
#elif !defined(__rtems__) && !defined(vxWorks)
pun.i[2] = getpid();
#else
pun.i[2] = 0xdeadbeef;
#endif
// and a bit of server instance within this process
pun.i[2] ^= uint32_t(effective.tcp_port)<<16u;
// maybe a little bit of randomness (eg. ASLR on Linux)
pun.i[2] ^= size_t(this);
if(sizeof(size_t)>4)
pun.i[2] ^= size_t(this)>>32u;
std::copy(pun.b.begin(), pun.b.end(), effective.guid.begin());
}
// Add magic "server" PV
{
auto L = sourcesLock.lockWriter();