Changes since v3: * Add NLM_F_CAPPED and NLM_F_ACK_TLVS flags, to allow entirely stateless parsing of the ACK messages by looking at the new flags. Need to check NLM_F_ACK_TLVS first, since capping can be done in kernels before this patchset without setting the flag. * Remove "missing_attr" functionality - this can obviously be added back rather easily, but I'd rather have more discussion about the nesting problem there. * Improve documentation of NLMSGERR_ATTR_OFFS * Improve message structure documentation, documenting that the request message is always capped for success cases * fix nlmsg_len of the outer message by calling nlmsg_end() * fix memcpy() of the request in success cases, going back to the original code that I'd changed before due to the payload adjustments that I reverted when introducing tlvlen
Big thanks to David Ahern for the feedback from changing iproute2! Patch for iw demonstrating the stateless parsing is here: https://p.sipsolutions.net/93ae7ea3afbba8d6.txt johannes
