Rename BEFORE_COLON/BC to avoid conflicts

[stgloorious]

Description

Rename the BEFORE_COLON and BC defines to include a MBEDTLS_ prefix and expand the BC to BEFORE_COLON.
The existing names are rather short and are not properly namespaced, increasing the likelihood for conflicts.

The defines are not even used in x509_crl.c, so remove them entirely there.

One example is the Renesas RA HAL headers that have variables named BC. Those headers are included into the mbedtls module via the sys/socket.h and arpa/inet.h headers in library/x509.crt.c which will eventually include CPU-specific headers containing the Renesas HAL. The conflict can be triggered with the https sample: west build -p auto -b ek_ra6m4 zephyr/samples/net/sockets/http_server, which will lead to

/home/stefan/Downloads/zephyr_test/modules/crypto/mbedtls/library/x509_crt.c:1750:25: error: expected identifier or '(' before string constant
 1750 | #define BC              "18"
      |                         ^~~~
/home/stefan/Downloads/zephyr_test/modules/hal/renesas/drivers/ra/fsp/src/bsp/cmsis/Device/RENESAS/Include/R7FA6M4AF.h:8100:27: note: in expansion of macro 'BC'
 8100 |             __IOM uint8_t BC   : 3;    /*!< [2..0] Bit Counter                                                        */
      |                           ^~

The include chain can be investigated by copying the GCC command, removing the -M* options, and adding -H.

Arguably, this conflict can also be solved by not including the socket.h and inet.h headers, e.g., by adding a special #ifdef __ZEPHYR__ case that defaults to the software version of inet_pton() just as it is done for Win32.
It could also be solved in the Renesas HAL header, but it makes more sense to me to fix the #define.

Consider this an RFC. Let me know if you have any better ideas to fix this. If this is accepted here I will submit it upstream as well.

PR checklist

• changelog not required
• 3.6 backport not required
• 2.28 backport not required
• tests not required

[tomi-font]

Hey, those changes should be submitted to upstream Mbed TLS: https://github.com/Mbed-TLS/mbedtls/pulls
They can then be cherry-picked into Zephyr.

[stgloorious]

The patches were merged upstream 243e13f. Please consider cherry-picking the commits or merging this PR now.

[tomi-font]

Great. Can you now just cherry pick the commits directly from upstream with the -x flag so we keep track of the commit hashes (useful for when updating this repo)?

[tomi-font]

You'll also need to make a PR in Zephyr if you want that change to land into main there.

[tomi-font]

Hmm, not quite right yet. The title of the commit should be identical to that of the upstream one. You shouldn't be using git merge, really just git cherry-pick.
Feel free to contact me on the Zephyr Discord if you need help doing that.

[stgloorious]

This is the merge commit from upstream (243e13f). I did

git cherry-pick -x upstream/development 243e13fb2a527d0df342c9a488209849120da558 -m 1

to pull it in. I think you want to see only my two commits, and not the merge commit? I tried doing that but it would always pull in the merge commit instead.

Thanks for the offer. I will try again as soon as I get back to work and then write you in case I don't manage to do it.

[tomi-font]

Ah yeah, kinda had forgotten that Mbed TLS merges PRs with merge commits.
Basically instead of cherry picking the merge commit you want to cherry pick your own commits, Mbed-TLS/mbedtls@6a9cf11 and Mbed-TLS/mbedtls@b5c079b.
So the full command you should use is: git cherry-pick -sx 6a9cf113611de1d8ac18f49563883a639ae7c7d6 b5c079b13c4977bdba8593d174d7851e41b5788e

[stgloorious]

Thanks, I think it worked now.

[tomi-font]

Perfect!

[facchinm]

We (Arduino) are impacted too by this bug while porting Portenta C33 (RA6M5 based) with networking, thanks @stgloorious for providing the fix!

[tomi-font]

Bear in mind (any of) you will need to make a PR in the main Zephyr repo that changes the reference to this repo (in the west.yml file) to this PR (pull/68/head) in order to integrate the changes into Zephyr.
see https://docs.zephyrproject.org/latest/develop/modules.html#process-for-submitting-changes-to-existing-modules

[stgloorious]

Done. Please consider merging this PR now, so I can update the hash in zephyrproject-rtos/zephyr#86704.

[tomi-font]

We first need to see that CI agrees. 🙂