I added the SockaddrCAN type to the golang.org/x/sys/unix package, and it works great. I create an issue with links the patch and some test code.
https://github.com/golang/go/issues/16188 On Fri, Jun 24, 2016 at 8:57 PM, Elliot Morrison-Reed <ellio...@gmail.com> wrote: > SocketCAN has been part of mainline linux since kernel 2.6.25 (so getting > close to a decade now), and it is pretty much the standard for all CAN bus > communication on linux. > > Thanks for the hint, I will look into adding support in the > golang.org/x/sys/unix package. > > Regards, > Elliot > > On Fri, Jun 24, 2016 at 7:52 PM, Ian Lance Taylor <i...@golang.org> wrote: > >> On Fri, Jun 24, 2016 at 8:05 AM, <ellio...@gmail.com> wrote: >> > >> > I am trying to set up an interface from Go to SocketCAN >> > (https://www.kernel.org/doc/Documentation/networking/can.txt). This >> > implements the linux socket interface, however it is a completely >> separate >> > socket type from the regular AF_INET or AF_UNIX socket types. >> > >> > The sockaddr struct for SocketCAN looks like this: >> > >> > struct sockaddr_can { >> > sa_family_t can_family; >> > int can_ifindex; >> > union { >> > /* transport protocol class address info (e.g. ISOTP) */ >> > struct { canid_t rx_id, tx_id; } tp; >> > >> > /* reserved for future CAN protocols address information */ >> > } can_addr; >> > }; >> > >> > >> > Since the union only has one possible entry right now, this is easy >> enough >> > to write in Go >> > >> > type CanID uint32 >> > >> > type sockaddrCan struct { >> > Family uint16 >> > IfIndex int32 >> > TpRxId CanID >> > TpTxId CanID >> > } >> > >> > >> > Everything is straight forward so far, but now if I want to pass this to >> > different syscall functions ( syscall.Bind, syscall.Connect, etc.) I >> have to >> > implement the syscall.Sockaddr interface, however looking in the code I >> see >> > this: >> > >> > type Sockaddr interface { >> > sockaddr() (ptr unsafe.Pointer, len _Socklen, err error) // >> lowercase; >> > only we can define Sockaddrs >> > } >> > >> > >> > So, finally the questions: >> > >> > Why is this interface private? It says that it is, but provides no >> > rationale. >> > Does this mean that I have to reimplement all the functions syscall >> > functions using raw syscall.Syscall? Or is there some clever way around >> > this so I can use the syscall package to make a Sockaddr type that is >> not >> > already defined. >> >> If this is going to be a standard thing in future Linux kernels, I >> suggest that you add support for it to the golang.org/x/sys/unix >> package. >> >> I don't actually know the answer to why Sockaddr has a private method. >> I agree that it doesn't seem strictly necessary. >> >> Ian >> > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
