zerotier: fix system include path

[jjm2473]

-isystem ext makes #include <miniupnpc/miniupnpc.h> actually include ext/miniupnpc/miniupnpc.h.

we should use $(STAGING_DIR)/usr/include as a higher priority system include path.

Fix openwrt/openwrt#18019

📦 Package Details

Maintainer: @
_{(You can find this by checking the history of the package Makefile.)}

Description:
Fix openwrt/openwrt#18019

---

🧪 Run Testing Details

• **OpenWrt Version: 24.10.1
• **OpenWrt Target/Subtarget: armsr/armv8
• **OpenWrt Device: virtualbox

---

✅ Formalities

• I have reviewed the CONTRIBUTING.md file for detailed contributing guidelines.

If your PR contains a patch:

• It can be applied using git am
• It has been refreshed to avoid offsets, fuzzes, etc., using

  make package/<your-package>/refresh V=s

• It is structured in a way that it is potentially upstreamable
  cannot be upstram, this is a part of openwrt cross compiling path hack.

[1715173329]

Cc maintainer @mwarning

[xuanranran]

This patch also fixes the issue with running ZeroTier on x86_64 firmware compiled with gcc14. Kudos to the author for providing the patch.

[qingtian110]

This method is proven to be effective istoreos/istoreos#2358 (comment)

[BKPepe]

This method is proven to be effective istoreos/istoreos#2358 (comment)

Yeah, it is being discussed in zerotier/ZeroTierOne#2453

and I see that @mwarning created this PR and it was merged: #26088 and it was also backported to OpenWrt 24.10 (#26323).

[jjm2473]

and I see that @mwarning created this PR and it was merged: #26088 and it was also backported to OpenWrt 24.10 (#26323).

@BKPepe

#26088 does not completly fix the issue openwrt/openwrt#18019, that's why it was reopened. Because zerotier still use it's own miniupnpc header, so MINIUPNPC_API_VERSION < 18 still true, the patched code did not take effect.

[jjm2473]

This method is proven to be effective istoreos/istoreos#2358 (comment)

Yes, this patch should also work, but it changes more .c .h source, this could easily lead to conflicts in the future.

[jjm2473]

@BKPepe I move CFLAGS to OpenWRT Makefile, is it better?

If it's better, I will squash two commits.

[Neustradamus]

@jjm2473: Thanks for your PR!

[1715173329]

The latter implementation looks better to me.

[1715173329]

btw please bump PKG_RELEASE

[BKPepe]

The latter implementation looks better to me.

Yeah, I agree this is much better. 💯 But the issue still lies within zerotier. They need to handle it.

[jjm2473]

Yeah, I agree this is much better. 💯 But the issue still lies within zerotier. They need to handle it.

The main problem is that zerotier does not officially support the use of external libminiupnpc when cross-compiling.