> On linux side I can see there is IP_HDRINCL option which configures > this. In the CHANGELOG I can see that support is added to LWIP in 2017 > but I can't see any usage in the code.
That changelog entry is a bit misleading. Support was only added to the core/callback/raw/native API, not the socket API. See [1] and [2]. From the last patch in the series: > This patch adds a new RAW_FLAGS_HDRINCL flag to the raw core > implementation. When this flag is set on a RAW PCB, [...] > > This feature allows the IP_HDRINCL socket option to be implemented > in higher layers with no further effort. [...] If you want to use the socket API, it sounds like all that's needed to add support is to define IP_HDRINCL (in lwip/sockets.h) and have lwip_setsockopt_impl call `raw_setflags(sock->conn->pcb.raw, RAW_FLAGS_HDRINCL)` for it. lwip_getsockopt_impl should also be able to retrieve the flag. If you aren't able to submit a patch, you could use the LWIP_HOOK_SOCKETS_SETSOCKOPT/GETSOCKOPT hooks. [1]: https://git.savannah.nongnu.org/cgit/lwip.git/log/?qt=range&q=52f448978f...e3435401f1 [2]: https://savannah.nongnu.org/patch/?9208 -Billy _______________________________________________ lwip-users mailing list lwip-users@nongnu.org https://lists.nongnu.org/mailman/listinfo/lwip-users
