From de0c75694ad9c9523bbe0d6920935d11627bc7d9 Mon Sep 17 00:00:00 2001
From: kgv <kgv@opencascade.com>
Date: Fri, 13 Nov 2020 19:59:24 +0300
Subject: [PATCH] 0031925: Foundation Classes, OSD_Host::InternetAddress() -
 possible NULL dereference on copying gethostbyname() result

Changes on non-Windows platforms:
- Deprecated gethostbyname() has been replaced by getifaddrs()+inet_ntop() handling IPv4+IPv6 addresses;
- External IPs are now preferred comparing to dummy localhost 127.0.0.1.
---
 src/OSD/OSD_Host.cxx                          | 72 +++++++++++++------
 .../STEPConstruct_AP203Context.cxx            | 12 +++-
 2 files changed, 60 insertions(+), 24 deletions(-)

diff --git a/src/OSD/OSD_Host.cxx b/src/OSD/OSD_Host.cxx
index 1547be3fbd..f3c7554e1f 100644
--- a/src/OSD/OSD_Host.cxx
+++ b/src/OSD/OSD_Host.cxx
@@ -21,10 +21,11 @@
 #include <Standard_NullObject.hxx>
 #include <TCollection_AsciiString.hxx>
 
-const OSD_WhoAmI Iam = OSD_WHost;
-
 #include <errno.h>
 
+#include <arpa/inet.h>
+#include <ifaddrs.h>
+
 #include <sys/utsname.h> // For 'uname'
 #include <netdb.h>       // This is for 'gethostbyname'
 #include <unistd.h>
@@ -89,7 +90,7 @@ char value[65];
 int status;
 
 status = gethostname(value, 64);
-if (status == -1) myError.SetValue(errno, Iam, "Host Name");
+if (status == -1) myError.SetValue(errno, OSD_WHost, "Host Name");
 
  result = value;
  return(result);
@@ -116,25 +117,52 @@ Standard_Integer OSD_Host::AvailableMemory(){
 
 // =========================================================================
 
-TCollection_AsciiString OSD_Host::InternetAddress(){
- struct hostent internet_address;
- int a,b,c,d;
- char buffer[16];
- TCollection_AsciiString result,host;
-
- host = HostName();
- memcpy(&internet_address,
-        gethostbyname(host.ToCString()),
-        sizeof(struct hostent));
-
- // Gets each bytes into integers
- a = (unsigned char)internet_address.h_addr_list[0][0];
- b = (unsigned char)internet_address.h_addr_list[0][1];
- c = (unsigned char)internet_address.h_addr_list[0][2];
- d = (unsigned char)internet_address.h_addr_list[0][3];
- sprintf(buffer,"%d.%d.%d.%d",a,b,c,d);
- result = buffer;
- return(result);
+TCollection_AsciiString OSD_Host::InternetAddress()
+{
+  TCollection_AsciiString aResult;
+  struct ifaddrs* anAddrFullInfo = NULL;
+  getifaddrs (&anAddrFullInfo);
+  for (struct ifaddrs* anAddrIter = anAddrFullInfo; anAddrIter != NULL; anAddrIter = anAddrIter->ifa_next)
+  {
+    if (!anAddrIter->ifa_addr)
+    {
+      continue;
+    }
+
+    if (anAddrIter->ifa_addr->sa_family == AF_INET)
+    {
+      // IP4 Address
+      char aBuffer[INET_ADDRSTRLEN];
+      void* aTmpAddrPtr = &((struct sockaddr_in* )anAddrIter->ifa_addr)->sin_addr;
+      inet_ntop (AF_INET, aTmpAddrPtr, aBuffer, sizeof(aBuffer));
+      if (strcmp (aBuffer, "127.0.0.1") != 0) // skip localhost address
+      {
+        aResult = aBuffer;
+        break;
+      }
+    }
+    else if (anAddrIter->ifa_addr->sa_family == AF_INET6)
+    {
+      // IP6 Address
+      char aBuffer[INET6_ADDRSTRLEN];
+      void* aTmpAddrPtr = &((struct sockaddr_in6 *)anAddrIter->ifa_addr)->sin6_addr;
+      inet_ntop (AF_INET6, aTmpAddrPtr, aBuffer, sizeof(aBuffer));
+      if (strcmp (aBuffer, "::1") != 0) // skip localhost address
+      {
+        aResult = aBuffer;
+        break;
+      }
+    }
+  }
+  if (anAddrFullInfo != NULL)
+  {
+    freeifaddrs (anAddrFullInfo);
+  }
+  if (aResult.IsEmpty())
+  {
+    return "127.0.0.1";
+  }
+  return aResult;
 }
 
 // =========================================================================
diff --git a/src/STEPConstruct/STEPConstruct_AP203Context.cxx b/src/STEPConstruct/STEPConstruct_AP203Context.cxx
index a5cae628cd..ad222a4b86 100644
--- a/src/STEPConstruct/STEPConstruct_AP203Context.cxx
+++ b/src/STEPConstruct/STEPConstruct_AP203Context.cxx
@@ -164,12 +164,20 @@ Handle(StepBasic_PersonAndOrganization) STEPConstruct_AP203Context::DefaultPerso
     OSD_Host aHost;
     TCollection_AsciiString anIP = aHost.InternetAddress();
     // cut off last number
-    Standard_Integer aLastDotIndex = anIP.SearchFromEnd (".");
-    if (aLastDotIndex >0)
+    const Standard_Integer aLastDotIndex = anIP.SearchFromEnd (".");
+    if (aLastDotIndex > 0)
     {
+      // IPv4
       anIP.Trunc (aLastDotIndex - 1);
       orgId->AssignCat (anIP.ToCString());
     }
+    else
+    {
+      // IPv6
+      const Standard_Integer aLastColonIndex = anIP.SearchFromEnd (":");
+      anIP.Trunc (aLastColonIndex - 1);
+      orgId->AssignCat (anIP.ToCString());
+    }
     
     // create organization
     Handle(StepBasic_Organization) aOrg = new StepBasic_Organization;
-- 
2.39.5