Attention is currently required from: laforge, pespin.

fixeria has posted comments on this change. ( 
https://gerrit.osmocom.org/c/libosmo-gprs/+/32644 )

Change subject: sm: Fix APN IE content not transmitted in Act PDP Ctx Req
......................................................................


Patch Set 1:

(1 comment)

File src/sm/sm_pdu.c:

https://gerrit.osmocom.org/c/libosmo-gprs/+/32644/comment/d65c78bd_87fdc48f
PS1, Line 208:  rc = osmo_apn_from_str(msg->tail, msgb_tailroom(msg), sme->apn);
             :          if (rc < 0)
             :                  return -EINVAL;
             :          *l = rc;
             :          msgb_put(msg, *l);
> IMHO this is highly unusual: passing a pointer to msg->tail and storing some 
> data before doing the msgb_put.  All the "legacy" code that I recall does the 
> msgb_put() first.  It would at that point ASSERT if we ever overrun 
> msgb_tailroom, before anything is memcpying over it.

I would not say it's highly unusual, but rather a common practice in cases when 
you don't know how much to `msgb_put()` before calling a buffer filling 
function, e.g. `read()` or `recv()`.

Below are grep results for all my local repositories (39 matches total):

```
$ ./gits do grep "msg->tail, msgb_tailroom" | grep "msgb_tailroom[(]" | wc -l
13
$ ./gits do grep "msg->data, msgb_tailroom" | grep "msgb_tailroom[(]" | wc -l
9
$ ./gits do grep "msgb_data(msg), msgb_tailroom" | grep "msgb_tailroom[(]" | wc 
-l
17
```



--
To view, visit https://gerrit.osmocom.org/c/libosmo-gprs/+/32644
To unsubscribe, or for help writing mail filters, visit 
https://gerrit.osmocom.org/settings

Gerrit-Project: libosmo-gprs
Gerrit-Branch: master
Gerrit-Change-Id: I70be2ff5e7e0fea5e93d7b9963064c38a0382f30
Gerrit-Change-Number: 32644
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <[email protected]>
Gerrit-Reviewer: Jenkins Builder
Gerrit-Reviewer: fixeria <[email protected]>
Gerrit-CC: laforge <[email protected]>
Gerrit-Attention: laforge <[email protected]>
Gerrit-Attention: pespin <[email protected]>
Gerrit-Comment-Date: Sun, 07 May 2023 06:22:24 +0000
Gerrit-HasComments: Yes
Gerrit-Has-Labels: No
Comment-In-Reply-To: laforge <[email protected]>
Gerrit-MessageType: comment

Reply via email to