From: Thomas Jarosch <thomas.jarosch@intra2net.com>
Date: Fri, 26 Aug 2011 13:55:20 +0000 (+0200)
Subject: Remove MegaAddr hack which gave unix sockets paths up to PATH_MAX: It's incompatible... 
X-Git-Tag: v0.3~11^2~2
X-Git-Url: http://developer.intra2net.com/git/?p=libasyncio;a=commitdiff_plain;h=a0508232438d4b0ff41644ab5aa7846141b88b42

Remove MegaAddr hack which gave unix sockets paths up to PATH_MAX: It's incompatible with the stack protector
---

diff --git a/asyncio/async_socket.cpp b/asyncio/async_socket.cpp
index 0e39394..1c4bdc9 100644
--- a/asyncio/async_socket.cpp
+++ b/asyncio/async_socket.cpp
@@ -43,8 +43,6 @@ namespace AsyncIo
 namespace
 {
 
-struct sockaddr_un dummy_un;
-
 /**
     Struct for holding sockaddr.
 
@@ -54,16 +52,17 @@ struct sockaddr_un dummy_un;
 
     This works as long as the POSIX functions don't verify the buffer length.
     For glibc on linux this is true.
+
+    UPDATE 2011-08-26:
+    Removed that buffer as the gcc stack protector chokes on this.
+
+    Now we are "limited" to 108 bytes again. The longest socket path
+    currently in use on the Intranator is 68 bytes. It looks already
+    longer than Richard Stallman's beard, so it should be fine.
 */
 union MegaAddr {
    struct sockaddr         m_addr;
-   struct sockaddr_in      m_addr_in;
    struct sockaddr_un      m_addr_un; // NOTE (historically) too small...
-   // storage is large enough to hold all sockaddr_* variants with the (historical) exception of _un !
-   struct sockaddr_storage m_addr_store;
-   // a char array large enough to hold _un (with an path up to the maximum allowed size!)
-   // (the +1 is added for a later 0-termination of the path)
-   char m_buffer[ sizeof(dummy_un) - sizeof(dummy_un.sun_path) + PATH_MAX + 1 ];
 };
 
 
@@ -119,13 +118,7 @@ void ServerSocketBaseImplementation::doRead()
       return;
    }
 
-   if (addrlen < sizeof(addr))
-   {
-      // in case of unix domain socket: terminate the path!
-      // NOTE we are doing this here since we don't pass the length info.
-      addr.m_buffer[addrlen]= 0;
-   }
-   else
+   if (addrlen >= sizeof(addr))
    {
       //something went terribly wrong!!
       // the resulting address structure is larger than it ever could be...
@@ -261,7 +254,10 @@ bool UnixIOSocket::open(const std::string& path)
    {
       MegaAddr addr;
       addr.m_addr_un.sun_family= AF_UNIX;
-      strncpy(addr.m_addr_un.sun_path, path.c_str(), PATH_MAX);                             //lint !e419
+
+      strncpy(addr.m_addr_un.sun_path, path.c_str(), sizeof(addr.m_addr_un.sun_path));
+      addr.m_addr_un.sun_path[sizeof(addr.m_addr_un.sun_path)-1] = '\0';
+
       if (::connect(fd,(sockaddr*)&addr.m_addr_un, SUN_LEN(&addr.m_addr_un)) < 0)           //lint !e413
       {
          m_errno= errno;
@@ -354,7 +350,10 @@ bool UnixServerSocketBase::open(const std::string& path, int mode)
    {
       MegaAddr addr;
       addr.m_addr_un.sun_family= AF_UNIX;
-      strncpy(addr.m_addr_un.sun_path, path.c_str(), PATH_MAX);                             //lint !e419
+
+      strncpy(addr.m_addr_un.sun_path, path.c_str(), sizeof(addr.m_addr_un.sun_path));
+      addr.m_addr_un.sun_path[sizeof(addr.m_addr_un.sun_path)-1] = '\0';
+
       Utils::unlink(path); // just in case...
       // NOTE this is a place which might require some updates for multithreaded
       // usage! (setting the umask affects all threads...)