getifaddrs never specifies broadcast addresses

Apple “Feedback” #12149764. According to man 3 getifaddrs: The ifa_dstaddr field references the destination address on a P2P interface, if one exists, otherwise it contains the broadcast address. In my testing the ifa_dstaddr field is never non-null. I’m not sure I have any suitably configured P2P interfaces, but I definitely have interfaces with broadcast capabilities … Read more

getifaddrs returns truncated sockaddr_in’s for AF_INET ifa_netmasks

Apple “Feedback” #12149675. Some netmasks returned by getifaddrs have family of AF_INET yet a length less than sizeof(sockaddr_in), e.g. 5, 6, 7, or 8. On macOS Ventura 13.3.1, at least. It looks like it’s actually allocating only eight bytes for the ifa_netmask (not the 16 that is the size of sockaddr_in per MacOSX13.3.sdk/usr/include/netinet/in.h), as it … Read more

iOS Family Sharing users cannot mix authentication schemes

Apple supports two styles of two-factor authentication, that they call (and distinguish as) “two-step” vs “two-factor”.  “Two-step” is their older method, though functionally they’re basically equivalent. If you have multiple accounts on a Family Sharing arrangement, and some use “two-factor” while others use “two-step”, you’re in for a bag of hurt. For example, any time you change … Read more

Rotated Windows

I’d forgotten about this until I stumbled across a reference to it again recently. This was a little hack I worked on back in 2004, with Mac OS X Tiger (10.4).  Yes, kids, macOS was called Mac OS X back in ye Olden Times. Wow, Slashdot looked even uglier than I remember, back then.  Though … Read more

Undocumented Swift conditional compilation macros

swift/lib/Basic/LangOptions.cpp has most of the conditional compilation macros (called “Language Options” in the compiler internally).  Notably the swift() version macro is absent, and doesn’t seem to be defined anywhere… At time of writing the two undocumented additions, to the os(), arch(), and swift() set, are _endian() and _runtime(). I have no idea if they’re useful … Read more

#if DEBUG in Swift

Sigh. The Swift team give an impeccable impression of a group of people who’ve never actually tried to use Swift. An incredibly basic compiler task is to provide code a way to distinguish between debug & release builds, in order that it can behave accordingly (e.g. change the default logging verbosity, change asserts from fatal to … Read more