Hi Alexander,
aahringo@xxxxxxxxxx wrote on Sun, 6 Nov 2022 21:01:35 -0500:
> Hi,
>
> On Wed, Nov 2, 2022 at 11:20 AM Miquel Raynal <miquel.raynal@xxxxxxxxxxx> wrote:
> >
> > Let's introduce the basics for advertizing discovered PANs and
> > coordinators, which is:
> > - A new "scan" netlink message group.
> > - A couple of netlink command/attribute.
> > - The main netlink helper to send a netlink message with all the
> > necessary information to forward the main information to the user.
> >
> > Two netlink attributes are proactively added to support future UWB
> > complex channels, but are not actually used yet.
> >
> > 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/net/cfg802154.h | 20 +++++++
> > include/net/nl802154.h | 44 ++++++++++++++
> > net/ieee802154/nl802154.c | 121 ++++++++++++++++++++++++++++++++++++++
> > net/ieee802154/nl802154.h | 6 ++
> > 4 files changed, 191 insertions(+)
> >
> > diff --git a/include/net/cfg802154.h b/include/net/cfg802154.h
> > index e1481f9cf049..8d67d9ed438d 100644
> > --- a/include/net/cfg802154.h
> > +++ b/include/net/cfg802154.h
> > @@ -260,6 +260,26 @@ struct ieee802154_addr {
> > };
> > };
> >
> > +/**
> > + * struct ieee802154_coord_desc - Coordinator descriptor
> > + * @coord: PAN ID and coordinator address
> > + * @page: page this coordinator is using
> > + * @channel: channel this coordinator is using
> > + * @superframe_spec: SuperFrame specification as received
> > + * @link_quality: link quality indicator at which the beacon was received
> > + * @gts_permit: the coordinator accepts GTS requests
> > + * @node: list item
> > + */
> > +struct ieee802154_coord_desc {
> > + struct ieee802154_addr *addr;
>
> Why is this a pointer?
No reason anymore, I've changed this member to be a regular structure.
>
> > + u8 page;
> > + u8 channel;
> > + u16 superframe_spec;
> > + u8 link_quality;
> > + bool gts_permit;
> > + struct list_head node;
> > +};
> > +
> > struct ieee802154_llsec_key_id {
> > u8 mode;
> > u8 id;
> > diff --git a/include/net/nl802154.h b/include/net/nl802154.h
> > index 145acb8f2509..cfe462288695 100644
> > --- a/include/net/nl802154.h
> > +++ b/include/net/nl802154.h
> > @@ -58,6 +58,9 @@ enum nl802154_commands {
> >
> > NL802154_CMD_SET_WPAN_PHY_NETNS,
> >
> > + NL802154_CMD_NEW_COORDINATOR,
> > + NL802154_CMD_KNOWN_COORDINATOR,
> > +
>
> NEW is something we never saw before and KNOWN we already saw before?
> I am not getting that when I just want to maintain a list in the user
> space and keep them updated, but I think we had this discussion
> already or? Currently they do the same thing, just the command is
> different. The user can use it to filter NEW and KNOWN? Still I am not
> getting it why there is not just a start ... event, event, event ....
> end. and let the user decide if it knows that it's new or old from its
> perspective.
Actually we already discussed this once and I personally liked more to
handle this in the kernel, but you seem to really prefer letting the
user space device whether or not the beacon is a new one or not, so
I've updated both the kernel side and the userspace side to act like
this.
>
> > /* add new commands above here */
> >
> > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > @@ -133,6 +136,8 @@ enum nl802154_attrs {
> > NL802154_ATTR_PID,
> > NL802154_ATTR_NETNS_FD,
> >
> > + NL802154_ATTR_COORDINATOR,
> > +
> > /* add attributes here, update the policy in nl802154.c */
> >
> > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > @@ -218,6 +223,45 @@ enum nl802154_wpan_phy_capability_attr {
> > NL802154_CAP_ATTR_MAX = __NL802154_CAP_ATTR_AFTER_LAST - 1
> > };
> >
> > +/**
> > + * enum nl802154_coord - Netlink attributes for a coord
> > + *
> > + * @__NL802154_COORD_INVALID: invalid
> > + * @NL802154_COORD_PANID: PANID of the coordinator (2 bytes)
> > + * @NL802154_COORD_ADDR: coordinator address, (8 bytes or 2 bytes)
> > + * @NL802154_COORD_CHANNEL: channel number, related to @NL802154_COORD_PAGE (u8)
> > + * @NL802154_COORD_PAGE: channel page, related to @NL802154_COORD_CHANNEL (u8)
> > + * @NL802154_COORD_PREAMBLE_CODE: Preamble code used when the beacon was received,
> > + * this is PHY dependent and optional (u8)
> > + * @NL802154_COORD_MEAN_PRF: Mean PRF used when the beacon was received,
> > + * this is PHY dependent and optional (u8)
> > + * @NL802154_COORD_SUPERFRAME_SPEC: superframe specification of the PAN (u16)
> > + * @NL802154_COORD_LINK_QUALITY: signal quality of beacon in unspecified units,
> > + * scaled to 0..255 (u8)
> > + * @NL802154_COORD_GTS_PERMIT: set to true if GTS is permitted on this PAN
> > + * @NL802154_COORD_PAYLOAD_DATA: binary data containing the raw data from the
> > + * frame payload, (only if beacon or probe response had data)
> > + * @NL802154_COORD_PAD: attribute used for padding for 64-bit alignment
> > + * @NL802154_COORD_MAX: highest coordinator attribute
> > + */
> > +enum nl802154_coord {
> > + __NL802154_COORD_INVALID,
> > + NL802154_COORD_PANID,
> > + NL802154_COORD_ADDR,
> > + NL802154_COORD_CHANNEL,
> > + NL802154_COORD_PAGE,
> > + NL802154_COORD_PREAMBLE_CODE,
>
> Interesting, if you do a scan and discover pans and others answers I
> would think you would see only pans on the same preamble. How is this
> working?
Yes this is how it is working, you only see PANs on one preamble at a
time. That's why we need to tell on which preamble we received the
beacon.
>
> > + NL802154_COORD_MEAN_PRF,
> > + NL802154_COORD_SUPERFRAME_SPEC,
> > + NL802154_COORD_LINK_QUALITY,
>
> not against it to have it, it's fine. I just think it is not very
> useful. A way to dump all LQI values with some timestamp and having
> something in user space to collect stats and do some heuristic may be
> better?
Actually I really like seeing this in the event logs in userspace, so if
you don't mind I'll keep this parameter. It can safely be ignored by the
userspace anyway, so I guess it does not hurt.
>
> > + NL802154_COORD_GTS_PERMIT,
> > + NL802154_COORD_PAYLOAD_DATA,
> > + NL802154_COORD_PAD,
> > +
> > + /* keep last */
> > + NL802154_COORD_MAX,
> > +};
> > +
> > /**
> > * enum nl802154_cca_modes - cca modes
> > *
> > diff --git a/net/ieee802154/nl802154.c b/net/ieee802154/nl802154.c
> > index e0b072aecf0f..f6fb7a228747 100644
> > --- a/net/ieee802154/nl802154.c
> > +++ b/net/ieee802154/nl802154.c
> > @@ -26,10 +26,12 @@ static struct genl_family nl802154_fam;
> > /* multicast groups */
> > enum nl802154_multicast_groups {
> > NL802154_MCGRP_CONFIG,
> > + NL802154_MCGRP_SCAN,
> > };
> >
> > static const struct genl_multicast_group nl802154_mcgrps[] = {
> > [NL802154_MCGRP_CONFIG] = { .name = "config", },
> > + [NL802154_MCGRP_SCAN] = { .name = "scan", },
> > };
> >
> > /* returns ERR_PTR values */
> > @@ -216,6 +218,9 @@ static const struct nla_policy nl802154_policy[NL802154_ATTR_MAX+1] = {
> >
> > [NL802154_ATTR_PID] = { .type = NLA_U32 },
> > [NL802154_ATTR_NETNS_FD] = { .type = NLA_U32 },
> > +
> > + [NL802154_ATTR_COORDINATOR] = { .type = NLA_NESTED },
> > +
> > #ifdef CONFIG_IEEE802154_NL802154_EXPERIMENTAL
> > [NL802154_ATTR_SEC_ENABLED] = { .type = NLA_U8, },
> > [NL802154_ATTR_SEC_OUT_LEVEL] = { .type = NLA_U32, },
> > @@ -1281,6 +1286,122 @@ static int nl802154_wpan_phy_netns(struct sk_buff *skb, struct genl_info *info)
> > return err;
> > }
> >
> > +static int nl802154_prep_new_coord_msg(struct sk_buff *msg,
> > + struct cfg802154_registered_device *rdev,
> > + struct wpan_dev *wpan_dev,
> > + u32 portid, u32 seq, int flags, u8 cmd,
> > + struct ieee802154_coord_desc *desc)
> > +{
> > + struct nlattr *nla;
> > + void *hdr;
> > +
> > + hdr = nl802154hdr_put(msg, portid, seq, flags, cmd);
> > + if (!hdr)
> > + return -ENOBUFS;
> > +
> > + if (nla_put_u32(msg, NL802154_ATTR_WPAN_PHY, rdev->wpan_phy_idx))
> > + goto nla_put_failure;
> > +
> > + if (wpan_dev->netdev &&
> > + nla_put_u32(msg, NL802154_ATTR_IFINDEX, wpan_dev->netdev->ifindex))
> > + goto nla_put_failure;
> > +
> > + if (nla_put_u64_64bit(msg, NL802154_ATTR_WPAN_DEV,
> > + wpan_dev_id(wpan_dev), NL802154_ATTR_PAD))
> > + goto nla_put_failure;
> > +
> > + nla = nla_nest_start_noflag(msg, NL802154_ATTR_COORDINATOR);
> > + if (!nla)
> > + goto nla_put_failure;
> > +
> > + if (nla_put(msg, NL802154_COORD_PANID, IEEE802154_PAN_ID_LEN,
> > + &desc->addr->pan_id))
> > + goto nla_put_failure;
> > +
> > + if (desc->addr->mode == IEEE802154_ADDR_SHORT) {
> > + if (nla_put(msg, NL802154_COORD_ADDR,
> > + IEEE802154_SHORT_ADDR_LEN,
> > + &desc->addr->short_addr))
> > + goto nla_put_failure;
> > + } else {
> > + if (nla_put(msg, NL802154_COORD_ADDR,
> > + IEEE802154_EXTENDED_ADDR_LEN,
> > + &desc->addr->extended_addr))
> > + goto nla_put_failure;
> > + }
> > +
> > + if (nla_put_u8(msg, NL802154_COORD_CHANNEL, desc->channel))
> > + goto nla_put_failure;
> > +
> > + if (nla_put_u8(msg, NL802154_COORD_PAGE, desc->page))
> > + goto nla_put_failure;
> > +
> > + if (nla_put_u16(msg, NL802154_COORD_SUPERFRAME_SPEC,
> > + desc->superframe_spec))
> > + goto nla_put_failure;
> > +
> > + if (nla_put_u8(msg, NL802154_COORD_LINK_QUALITY, desc->link_quality))
> > + goto nla_put_failure;
> > +
> > + if (desc->gts_permit && nla_put_flag(msg, NL802154_COORD_GTS_PERMIT))
> > + goto nla_put_failure;
> > +
> > + /* TODO: NL802154_COORD_PAYLOAD_DATA if any */
> > +
> > + nla_nest_end(msg, nla);
> > +
> > + genlmsg_end(msg, hdr);
> > +
> > + return 0;
> > +
> > + nla_put_failure:
> > + genlmsg_cancel(msg, hdr);
> > +
> > + return -EMSGSIZE;
> > +}
> > +
> > +static int nl802154_advertise_coordinator(struct wpan_phy *wpan_phy,
> > + struct wpan_dev *wpan_dev, u8 cmd,
> > + struct ieee802154_coord_desc *desc)
> > +{
> > + struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(wpan_phy);
> > + struct sk_buff *msg;
> > + int ret;
> > +
> > + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
> > + if (!msg)
> > + return -ENOMEM;
> > +
> > + ret = nl802154_prep_new_coord_msg(msg, rdev, wpan_dev, 0, 0, 0, cmd, desc);
> > + if (ret < 0) {
> > + nlmsg_free(msg);
> > + return ret;
> > + }
> > +
> > + return genlmsg_multicast_netns(&nl802154_fam, wpan_phy_net(wpan_phy),
> > + msg, 0, NL802154_MCGRP_SCAN, GFP_ATOMIC);
> > +}
>
> ah, okay that answers my previous question... regarding the trace event.
>
> - Alex
>
Thanks,
Miquèl
