Hi,
On Mon, Feb 6, 2023 at 7:33 PM Alexander Aring <aahringo@xxxxxxxxxx> wrote:
>
> Hi,
>
> On Mon, Feb 6, 2023 at 4:13 AM Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote:
> >
> > Hi Alexander,
> >
> > aahringo@xxxxxxxxxx wrote on Sun, 5 Feb 2023 20:39:32 -0500:
> >
> > > Hi,
> > >
> > > On Tue, Nov 29, 2022 at 11:02 AM Miquel Raynal
> > > <miquel.raynal@xxxxxxxxxxx> wrote:
> > > >
> > > > The ieee802154 layer should be able to scan a set of channels in order
> > > > to look for beacons advertizing PANs. Supporting this involves adding
> > > > two user commands: triggering scans and aborting scans. The user should
> > > > also be notified when a new beacon is received and also upon scan
> > > > termination.
> > > >
> > > > A scan request structure is created to list the requirements and to be
> > > > accessed asynchronously when changing channels or receiving beacons.
> > > >
> > > > Mac layers may now implement the ->trigger_scan() and ->abort_scan()
> > > > hooks.
> > > >
> > > > Co-developed-by: David Girault <david.girault@xxxxxxxxx>
> > > > Signed-off-by: David Girault <david.girault@xxxxxxxxx>
> > > > Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> > > > ---
> > > > include/linux/ieee802154.h | 3 +
> > > > include/net/cfg802154.h | 25 +++++
> > > > include/net/nl802154.h | 49 +++++++++
> > > > net/ieee802154/nl802154.c | 215 +++++++++++++++++++++++++++++++++++++
> > > > net/ieee802154/nl802154.h | 3 +
> > > > net/ieee802154/rdev-ops.h | 28 +++++
> > > > net/ieee802154/trace.h | 40 +++++++
> > > > 7 files changed, 363 insertions(+)
> > > >
> > > > diff --git a/include/linux/ieee802154.h b/include/linux/ieee802154.h
> > > > index 0303eb84d596..b22e4147d334 100644
> > > > --- a/include/linux/ieee802154.h
> > > > +++ b/include/linux/ieee802154.h
> > > > @@ -44,6 +44,9 @@
> > > > #define IEEE802154_SHORT_ADDR_LEN 2
> > > > #define IEEE802154_PAN_ID_LEN 2
> > > >
> > > > +/* Duration in superframe order */
> > > > +#define IEEE802154_MAX_SCAN_DURATION 14
> > > > +#define IEEE802154_ACTIVE_SCAN_DURATION 15
> > > > #define IEEE802154_LIFS_PERIOD 40
> > > > #define IEEE802154_SIFS_PERIOD 12
> > > > #define IEEE802154_MAX_SIFS_FRAME_SIZE 18
> > > > diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
> > > > index d09c393d229f..76d4f95e9974 100644
> > > > --- a/include/net/cfg802154.h
> > > > +++ b/include/net/cfg802154.h
> > > > @@ -18,6 +18,7 @@
> > > >
> > > > struct wpan_phy;
> > > > struct wpan_phy_cca;
> > > > +struct cfg802154_scan_request;
> > > >
> > > > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > > > struct ieee802154_llsec_device_key;
> > > > @@ -67,6 +68,10 @@ struct cfg802154_ops {
> > > > struct wpan_dev *wpan_dev, bool mode);
> > > > int (*set_ackreq_default)(struct wpan_phy *wpan_phy,
> > > > struct wpan_dev *wpan_dev, bool ackreq);
> > > > + int (*trigger_scan)(struct wpan_phy *wpan_phy,
> > > > + struct cfg802154_scan_request *request);
> > > > + int (*abort_scan)(struct wpan_phy *wpan_phy,
> > > > + struct wpan_dev *wpan_dev);
> > > > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > > > void (*get_llsec_table)(struct wpan_phy *wpan_phy,
> > > > struct wpan_dev *wpan_dev,
> > > > @@ -278,6 +283,26 @@ struct ieee802154_coord_desc {
> > > > bool gts_permit;
> > > > };
> > > >
> > > > +/**
> > > > + * struct cfg802154_scan_request - Scan request
> > > > + *
> > > > + * @type: type of scan to be performed
> > > > + * @page: page on which to perform the scan
> > > > + * @channels: channels in te %page to be scanned
> > > > + * @duration: time spent on each channel, calculated with:
> > > > + * aBaseSuperframeDuration * (2 ^ duration + 1)
> > > > + * @wpan_dev: the wpan device on which to perform the scan
> > > > + * @wpan_phy: the wpan phy on which to perform the scan
> > > > + */
> > > > +struct cfg802154_scan_request {
> > > > + enum nl802154_scan_types type;
> > > > + u8 page;
> > > > + u32 channels;
> > > > + u8 duration;
> > > > + struct wpan_dev *wpan_dev;
> > > > + struct wpan_phy *wpan_phy;
> > > > +};
> > > > +
> > > > struct ieee802154_llsec_key_id {
> > > > u8 mode;
> > > > u8 id;
> > > > diff --git a/include/net/nl802154.h b/include/net/nl802154.h
> > > > index b79a89d5207c..79fbd820b25a 100644
> > > > --- a/include/net/nl802154.h
> > > > +++ b/include/net/nl802154.h
> > > > @@ -73,6 +73,9 @@ enum nl802154_commands {
> > > > NL802154_CMD_DEL_SEC_LEVEL,
> > > >
> > > > NL802154_CMD_SCAN_EVENT,
> > > > + NL802154_CMD_TRIGGER_SCAN,
> > > > + NL802154_CMD_ABORT_SCAN,
> > > > + NL802154_CMD_SCAN_DONE,
> > > >
> > > > /* add new commands above here */
> > > >
> > > > @@ -134,6 +137,12 @@ enum nl802154_attrs {
> > > > NL802154_ATTR_NETNS_FD,
> > > >
> > > > NL802154_ATTR_COORDINATOR,
> > > > + NL802154_ATTR_SCAN_TYPE,
> > > > + NL802154_ATTR_SCAN_FLAGS,
> > > > + NL802154_ATTR_SCAN_CHANNELS,
> > > > + NL802154_ATTR_SCAN_PREAMBLE_CODES,
> > > > + NL802154_ATTR_SCAN_MEAN_PRF,
> > > > + NL802154_ATTR_SCAN_DURATION,
> > > >
> > > > /* add attributes here, update the policy in nl802154.c */
> > > >
> > > > @@ -259,6 +268,46 @@ enum nl802154_coord {
> > > > NL802154_COORD_MAX,
> > > > };
> > > >
> > > > +/**
> > > > + * enum nl802154_scan_types - Scan types
> > > > + *
> > > > + * @__NL802154_SCAN_INVALID: scan type number 0 is reserved
> > > > + * @NL802154_SCAN_ED: An ED scan allows a device to obtain a measure of the peak
> > > > + * energy in each requested channel
> > > > + * @NL802154_SCAN_ACTIVE: Locate any coordinator transmitting Beacon frames using
> > > > + * a Beacon Request command
> > > > + * @NL802154_SCAN_PASSIVE: Locate any coordinator transmitting Beacon frames
> > > > + * @NL802154_SCAN_ORPHAN: Relocate coordinator following a loss of synchronisation
> > > > + * @NL802154_SCAN_ENHANCED_ACTIVE: Same as Active using Enhanced Beacon Request
> > > > + * command instead of Beacon Request command
> > > > + * @NL802154_SCAN_RIT_PASSIVE: Passive scan for RIT Data Request command frames
> > > > + * instead of Beacon frames
> > > > + * @NL802154_SCAN_ATTR_MAX: Maximum SCAN attribute number
> > > > + */
> > > > +enum nl802154_scan_types {
> > > > + __NL802154_SCAN_INVALID,
> > > > + NL802154_SCAN_ED,
> > > > + NL802154_SCAN_ACTIVE,
> > > > + NL802154_SCAN_PASSIVE,
> > > > + NL802154_SCAN_ORPHAN,
> > > > + NL802154_SCAN_ENHANCED_ACTIVE,
> > > > + NL802154_SCAN_RIT_PASSIVE,
> > > > +
> > > > + /* keep last */
> > > > + NL802154_SCAN_ATTR_MAX,
> > > > +};
> > > > +
> > > > +/**
> > > > + * enum nl802154_scan_flags - Scan request control flags
> > > > + *
> > > > + * @NL802154_SCAN_FLAG_RANDOM_ADDR: use a random MAC address for this scan (ie.
> > > > + * a different one for every scan iteration). When the flag is set, full
> > > > + * randomisation is assumed.
> > > > + */
> > > > +enum nl802154_scan_flags {
> > > > + NL802154_SCAN_FLAG_RANDOM_ADDR = BIT(0),
> > > > +};
> > > > +
> > > > /**
> > > > * enum nl802154_cca_modes - cca modes
> > > > *
> > > > diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
> > > > index 80dc73182785..c497ffd8e897 100644
> > > > --- a/net/ieee802154/nl802154.c
> > > > +++ b/net/ieee802154/nl802154.c
> > > > @@ -221,6 +221,12 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
> > > >
> > > > [NL802154_ATTR_COORDINATOR] = { .type = NLA_NESTED },
> > > >
> > > > + [NL802154_ATTR_SCAN_TYPE] = { .type = NLA_U8 },
> > > > + [NL802154_ATTR_SCAN_CHANNELS] = { .type = NLA_U32 },
> > > > + [NL802154_ATTR_SCAN_PREAMBLE_CODES] = { .type = NLA_U64 },
> > > > + [NL802154_ATTR_SCAN_MEAN_PRF] = { .type = NLA_U8 },
> > > > + [NL802154_ATTR_SCAN_DURATION] = { .type = NLA_U8 },
> > > > +
> > > > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > > > [NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
> > > > [NL802154_ATTR_SEC_OUT_LEVEL] = { .type = NLA_U32, },
> > > > @@ -1384,6 +1390,199 @@ int nl802154_scan_event(struct wpan_phy *wpan_phy, struct wpan_dev *wpan_dev,
> > > > }
> > > > EXPORT_SYMBOL_GPL(nl802154_scan_event);
> > > >
> > > > +static int nl802154_trigger_scan(struct sk_buff *skb, struct genl_info *info)
> > > > +{
> > > > + struct cfg802154_registered_device *rdev = info->user_ptr[0];
> > > > + struct net_device *dev = info->user_ptr[1];
> > > > + struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
> > > > + struct wpan_phy *wpan_phy = &rdev->wpan_phy;
> > > > + struct cfg802154_scan_request *request;
> > > > + u8 type;
> > > > + int err;
> > > > +
> > > > + /* Monitors are not allowed to perform scans */
> > > > + if (wpan_dev->iftype == NL802154_IFTYPE_MONITOR)
> > > > + return -EPERM;
> > >
> > > btw: why are monitors not allowed?
> >
> > I guess I had the "active scan" use case in mind which of course does
> > not work with monitors. Maybe I can relax this a little bit indeed,
> > right now I don't remember why I strongly refused scans on monitors.
>
> Isn't it that scans really work close to phy level? Means in this case
> we disable mostly everything of MAC filtering on the transceiver side.
> Then I don't see any reasons why even monitors can't do anything, they
> also can send something. But they really don't have any specific
> source address set, so long addresses are none for source addresses, I
> don't see any problem here. They also don't have AACK handling, but
> it's not required for scan anyway...
>
> If this gets too complicated right now, then I am also fine with
> returning an error here, we can enable it later but would it be better
> to use ENOTSUPP or something like that in this case? EPERM sounds like
> you can do that, but you don't have the permissions.
>
For me a scan should also be possible from iwpan phy $PHY scan (or
whatever the scan command is, or just enable beacon)... to go over the
dev is just a shortcut for "I mean whatever the phy is under this dev"
?
- Alex
