dhcpcd-discuss

Roy, sorry for taking so long to reply. Given this is my work laptop, 'real' work has been getting in the way of me doing useful 
stuff like this :)

Roy Marples wrote:
> OK, hooking into rfkill is the wrong thing todo.
> However, if the switch is toggled, the kernel should emit netlink 
> messages to indicate this.
> Can you see if this is the case? if-linux.c, lines 1-310 are of interest.

There's an rfkill netlink message that's visible on NETLINK_KOBJECT_UEVENT, nothing obvious from NETLINK_ROUTE from 'ip monitor 
all'.  However if I either use the rfkill event to run 'ip link set up dev wlan0' or type that manually then I will see 
NETLINK_ROUTE messages for that.

With ip monitor all running I can remove the driver for the wired nic, see the netlink messages for that and have dhcpcd react 
accordingly.
However, with the rfkill switch enabled if I remove and reload the iwl3945 module, while I still see the netlink messages from ip 
monitor there's nothing from dhcpcd.

> dhcpcd reacts to new interface link messages sent via the kernel.
> So if ifconfig UP fails with ENODEV, then I would logically expect a 
> kernel announcement that the interface is available when the rfkill 
> switch is toggled to indicate the interface is now ready.

Sorry if this is a bit long, but hopefully there's enough information here to help.

Immediately after boot, have done nothing other than load the drivers at this point, dhcpcd is not running, wpa_supplicant is 
running on wlan0. I have no dhcpcd.conf or /libexec/dhcpcd-run-hooks installed so there should be nothing happening behind my back 
here. dhcpcd version is from git earlier this evening.

root@craptop:~# ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff
3: wmaster0: <> mtu 0 qdisc noop state DOWN qlen 1000
    link/ieee802.11 00:1c:bf:a0:13:d7 brd 00:00:00:00:00:00
4: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff

root@craptop:~# ip link set up dev wlan0
RTNETLINK answers: No such device


root@craptop:~/dhcpcd/git/dhcpcd# ./dhcpcd -d -B
dhcpcd: version 5.0.99 starting
dhcpcd: eth0: executing `/libexec/dhcpcd-run-hooks', reason PREINIT
dhcpcd: /libexec/dhcpcd-run-hooks: No such file or directory
dhcpcd: eth0: executing `/libexec/dhcpcd-run-hooks', reason NOCARRIER
dhcpcd: /libexec/dhcpcd-run-hooks: No such file or directory
dhcpcd: eth0: waiting for carrier


press rfkill button - no reaction from dhcpcd, nothing from ip monitor

listening to NETLINK_KOBJECT_UEVENT shows

change@/devices/platform/hp-wmi/rfkill/rfkill1
ACTION=change
DEVPATH=/devices/platform/hp-wmi/rfkill/rfkill1
SUBSYSTEM=rfkill
RFKILL_NAME=hp-wifi
RFKILL_TYPE=wlan
RFKILL_STATE=1
SEQNUM=598

root@craptop:~# ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff
3: wmaster0: <> mtu 576 qdisc noop state DOWN qlen 1000
    link/ieee802.11 00:1c:bf:a0:13:d7 brd 00:00:00:00:00:00
4: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff

root@craptop:~# ip link set up dev wlan0

again, no reaction from dhcpcd, NETLINK_KOBJECT_UEVENT shows

add@/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::radio
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::radio
SUBSYSTEM=leds
SEQNUM=622


add@/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::assoc
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::assoc
SUBSYSTEM=leds
SEQNUM=623


add@/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::RX
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::RX
SUBSYSTEM=leds
SEQNUM=624


add@/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::TX
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:1c.1/0000:10:00.0/leds/iwl-phy0::TX
SUBSYSTEM=leds
SEQNUM=625


ip monitor shows

5: wmaster0: <UP,LOWER_UP> mtu 576 qdisc pfifo_fast state UNKNOWN
    link/ieee802.11 00:1c:bf:a0:13:d7 brd 00:00:00:00:00:00
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DORMANT
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff
0.0.0.0 dev lo lladdr 00:00:00:00:00:00 NOARP
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP>
    link/ether
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP>
    link/ether
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP>
    link/ether
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP>
    link/ether
6: wlan0: <NO-CARRIER,BROADCAST,MULTICAST,UP>
    link/ether

[wpa_supplicant is running here so this repeats as it tries to associate]



With rfkill enabled..

root@craptop:~# rmmod iwl3945

[from ip monitor all]
Deleted 4: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff
Deleted 3: wmaster0: <> mtu 576 qdisc noop state DOWN
    link/ieee802.11 00:1c:bf:a0:13:d7 brd 00:00:00:00:00:00

root@craptop:~# modprobe iwl3945

[from ip monitor all]
5: wmaster0: <> mtu 0 qdisc noop state DOWN
    link/ieee802.11 00:1c:bf:a0:13:d7 brd 00:00:00:00:00:00
6: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
    link/ether 00:1c:bf:a0:13:d7 brd ff:ff:ff:ff:ff:ff
6: wlan0: <BROADCAST,MULTICAST>
    link/ether

there's no reaction to either of the above actions from dhcpcd


root@craptop:~# rmmod tg3

[from ip monitor all]
2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff
Deleted 2: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff

dhcpcd: eth0: removing interface
dhcpcd: eth0: executing `/libexec/dhcpcd-run-hooks', reason STOP
dhcpcd: /libexec/dhcpcd-run-hooks: No such file or directory


root@craptop:~# modprobe tg3

[from ip monitor all]
7: eth0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff
7: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state UNKNOWN
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff
7: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN
    link/ether 00:1c:c4:c9:2c:97 brd ff:ff:ff:ff:ff:ff


dhcpcd: eth0: executing `/libexec/dhcpcd-run-hooks', reason PREINIT
dhcpcd: /libexec/dhcpcd-run-hooks: No such file or directory
dhcpcd: eth0: executing `/libexec/dhcpcd-run-hooks', reason NOCARRIER
dhcpcd: /libexec/dhcpcd-run-hooks: No such file or directory
dhcpcd: eth0: waiting for carrier