sendmsg in libc_lwip

hello,

I am looking in plugin implementation to have deep understand about it. my objective is to implement the "sendmsg" function.

i was able to mange it but when i am compiling i got error message tell me that the " struct msghdr and iovec" were defined twice ! .

I add the the definition of struct msghdr and struct iovec in /include /lwip/lwip/sockets.h and they are already defined in /libc/sys/socket.h .

i am really confused since there are many data types defined in the both headers (e.g sockadd) and libc_lwip was never complained !

best,