Fixed DNS resolution bug in Windows

Due to a bug in unbound, we were passing a string containing a null
character to ub_ctx_resolvconf and ub_ctx_hosts rather than a NULL
pointer.  On *nix this wasn't causing headache, but on Windows this was
causing unbound to not correctly load DNS settings from the OS.

Note on the bug: in a Windows-specific code branch in the function
ub_ctx_hosts(), if the hosts file specified was a NULL pointer, a call
to getenv() was stored in a local char* and later freed.  This is
incorrect, as we do not own that data, and caused the program to crash.
This commit is contained in:
Thomas Winget 2015-04-02 09:22:31 -04:00
parent b0151de601
commit c0de96f8bd
No known key found for this signature in database
GPG key ID: 58131A160789E630
2 changed files with 2 additions and 5 deletions

View file

@ -1028,7 +1028,6 @@ ub_ctx_hosts(struct ub_ctx* ctx, const char* fname)
"\\hosts");
retval=ub_ctx_hosts(ctx, buf);
}
free(name);
return retval;
}
return UB_READFILE;

View file

@ -162,11 +162,9 @@ DNSResolver::DNSResolver() : m_data(new DNSResolverData())
// init libunbound context
m_data->m_ub_context = ub_ctx_create();
char empty_string = '\0';
// look for "/etc/resolv.conf" and "/etc/hosts" or platform equivalent
ub_ctx_resolvconf(m_data->m_ub_context, &empty_string);
ub_ctx_hosts(m_data->m_ub_context, &empty_string);
ub_ctx_resolvconf(m_data->m_ub_context, NULL);
ub_ctx_hosts(m_data->m_ub_context, NULL);
ub_ctx_add_ta(m_data->m_ub_context, ::get_builtin_ds());
}