| Message ID | 20170801111439.1143-3-privat@egil-hjelmeland.no |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
Hi Egil, On Tuesday 01 August 2017 13:14:38 Egil Hjelmeland wrote: > Will be used instead of '3' in upcomming patches. > > Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no> > --- > drivers/net/dsa/lan9303-core.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/net/dsa/lan9303-core.c > b/drivers/net/dsa/lan9303-core.c index 4c514d3b9f68..2a3c6bf473dd 100644 > --- a/drivers/net/dsa/lan9303-core.c > +++ b/drivers/net/dsa/lan9303-core.c > @@ -20,6 +20,8 @@ > > #include "lan9303.h" > > +#define LAN9303_NUM_PORTS 3 > + > /* 13.2 System Control and Status Registers > * Multiply register number by 4 to get address offset. > */ 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
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. Let's hear what other mean. Egil
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
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. > Sounds like a plan for a later patch, when changing to dsa_switch_alloc(LAN9303_NUM_PORTS) > Andrew > Egil
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
> 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? Yes. Andrew
diff --git a/drivers/net/dsa/lan9303-core.c b/drivers/net/dsa/lan9303-core.c index 4c514d3b9f68..2a3c6bf473dd 100644 --- a/drivers/net/dsa/lan9303-core.c +++ b/drivers/net/dsa/lan9303-core.c @@ -20,6 +20,8 @@ #include "lan9303.h" +#define LAN9303_NUM_PORTS 3 + /* 13.2 System Control and Status Registers * Multiply register number by 4 to get address offset. */
Will be used instead of '3' in upcomming patches. Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no> --- drivers/net/dsa/lan9303-core.c | 2 ++ 1 file changed, 2 insertions(+)