I'm looking for an open source license which grants me additional privileges.

Features:

• Anyone can freely modify, fork, use the code, as long as they make their source changes publicly available. They can use it in other open source projects, but not in closed-source projects.
• Only I and entities I specifically designate can use the code as part of a closed-source application. I am also exempt from the duty to publish the source code changes.

I'm not trying to forbid the commercial use, just to allow myself more flexibility to use the code, while still contributing to open source. I don't want to burn myself by being legally forbidden from using the libraries I wrote in my commercial projects.

Large companies use such dual licenses to maintain an open source project, while also selling the premium version.

Which licenses of this type are available? What caveats or obstacles exist?