Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH v2 net-next 2/3] net: dsa: lan9303: define LAN9303_NUM_PORTS 3 | From | Egil Hjelmeland <> | Date | Thu, 3 Aug 2017 11:53:23 +0200 |
| |
On 01. aug. 2017 15:27, Andrew Lunn wrote: > On Tue, Aug 01, 2017 at 02:31:44PM +0200, Egil Hjelmeland wrote: >> On 01. aug. 2017 13:49, Juergen Borleis wrote: >>> Hi Egil, >>> >>> On Tuesday 01 August 2017 13:14:38 Egil Hjelmeland wrote: >>>> Will be used instead of '3' in upcomming patches. >>>> >>>> >>>> +#define LAN9303_NUM_PORTS 3 >>>> + >>> >>> Maybe we should put this macro into a shared location because >>> in "net/dsa/tag_lan9303.c" there is already a "#define LAN9303_MAX_PORTS >>> 3". >>> >>> jb >>> >> >> Is there any suitable shared location for such driver specific >> definitions? >> I could change the name to LAN9303_MAX_PORTS so it the same. >> Rhymes better with DSA_MAX_PORTS too. > > Hi Egil, Juergen > > The other tag drivers do: > > if (source_port >= ds->num_ports || !ds->ports[source_port].netdev) > return NULL; > > or just > > if (!ds->ports[port].netdev) > return NULL; > > The first version is the safest, since a malicious switch could return > port 42, and you are accessing way off the end of ds->ports[]. It does > however require you call dsa_switch_alloc() with the correct number of > ports. > > Andrew >
Related question: If the driver does dsa_switch_alloc(3), can it then trust that all "port" params passed in DSA methods will be between 0 and 2?
Egil
| ![\](/images/icornerr.gif) |