Commit d9506cd41ce98e10a29c25c4766878367103bb2d attempts to fix ping in netconsole [1] but IIUC the fix is incomplete (at least in our config).
[1] https://patchwork.ozlabs.org/project/uboot/patch/20201221034439.2747170-1-yl...
Two issues were identified:
Firstly that the logic of eth_halt() in the various network operations would break an already running netconsole.
Secondly, netconsole uses the net output buffer which means that any nested network operation (such as arp or ping) will cause an overwrite of the netconsole data.
Marked as RFC since not all network protocols have been tested, and not all nc configurations have been tested (e.g. broadcast address).
Tested against ge_bx50v3_defconfig (i.MX6) using the fec.
Tested against 2020.10 050acee119b3757fee3bd128f55d720fdd9bb890, using a configuration that includes CONFIG_NETCONSOLE, CONFIG_CMD_NFS, and CONFIG_CMD_PING.
A sample session is as follows:
Configure (via serial console)
=> env set ethaddr ca:fe:de:ca:f0:11 ; env set ipaddr 192.168.120.49 ; setenv stdout serial,nc; setenv stdin serial,nc => env set ncip 192.168.120.1
Invoke net console
./netconsole 192.168.120.49
Invoke ping (via serial console)
=> ping 192.168.120.1 Using ethernet@2188000 device host 192.168.120.1 is alive => _
Output on net console
Board out port: 6666 Board in port: 6666 NOTE: the interrupt signal (normally ^C) has been remapped to ^T ncb: not found
=> ping 192.168.120.1 Using ethernet@2188000 device host 192.168.120.1 is alive =>
Invoke ping (via netconsole) for an IP address that is not reachable. Type ^C to abort. The ^C is not echoed.
=> ping 192.168.120.2 Using ethernet@2188000 device
Abort ping failed; host 192.168.120.2 is not alive => _
Output on serial console
=> ping 192.168.120.2 Using ethernet@2188000 device
Abort ping failed; host 192.168.120.2 is not alive =>
The following tcpdump fragment captures the typing of the letters "ok" in the net console. There was approximately 3 seconds between each letter.
> sudo tcpdump -i enx001a9f0c4f04 -n host 192.168.120.49 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on enx001a9f0c4f04, link-type EN10MB (Ethernet), capture size 262144 bytes 14:20:05.856372 IP 192.168.120.1.53891 > 192.168.120.49.6666: UDP, length 1 'o' from host (nc stdin) to target 14:20:05.856684 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:20:05.856709 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:20:05.856981 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 1 'o' from target (stdout) to host 14:20:06.626637 ARP, Request who-has 192.168.120.49 tell 192.168.120.1, length 28 14:20:06.626915 ARP, Reply 192.168.120.49 is-at ca:fe:de:ca:f0:11, length 46 14:20:09.364465 IP 192.168.120.1.53891 > 192.168.120.49.6666: UDP, length 1 'k' from host to target 14:20:09.364776 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:20:09.364794 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:20:09.365041 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 1 'k' from target to host
The following tcpdump fragment captures the typing of the letters "ok" in the serial console. There was approximately 3 seconds between each letter.
14:22:48.225004 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:22:48.225032 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:22:48.225291 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 1 'o' from target (stdout) to host 14:22:51.777002 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:22:51.777031 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:22:51.777251 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 1 'k' from target to host
The following tcpdump fragment captures ping to a known host. (Not shown: the command "ping 192.168.120.1")
14:23:56.873103 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:23:56.873131 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:23:56.873426 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 1 '\n' 14:23:56.876020 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 30 "Using ethernet@2188000 device" 14:23:56.876021 ARP, Request who-has 192.168.120.1 tell 192.168.120.49, length 46 14:23:56.876060 ARP, Reply 192.168.120.1 is-at 00:1a:9f:0c:4f:04, length 28 14:23:56.876354 IP 192.168.120.49 > 192.168.120.1: ICMP echo request, id 0, seq 5, length 8 14:23:56.876385 IP 192.168.120.1 > 192.168.120.49: ICMP echo reply, id 0, seq 5, length 8 14:23:56.879037 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 28 "host 192.168.120.1 is alive" 14:23:56.879272 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 3 "=> " 14:24:01.890653 ARP, Request who-has 192.168.120.49 tell 192.168.120.1, length 28 14:24:01.890933 ARP, Reply 192.168.120.49 is-at ca:fe:de:ca:f0:11, length 46
And, finally, the following tcpdump fragment captures ping to an unknown host. (Not shown: the command "ping 192.168.120.2")
14:35:57.680889 ARP, Request who-has 192.168.120.2 tell 192.168.120.49, length 46 14:36:02.681255 ARP, Request who-has 192.168.120.2 tell 192.168.120.49, length 46 14:36:02.786656 ARP, Request who-has 192.168.120.49 tell 192.168.120.1, length 28 14:36:02.786953 ARP, Reply 192.168.120.49 is-at ca:fe:de:ca:f0:11, length 46 14:36:04.154698 IP 192.168.120.1.53891 > 192.168.120.49.6666: UDP, length 1 ^C 14:36:04.155671 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 7 "Abort" 14:36:04.159672 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 45 "ping failed; host 192.168.120.2 is not alive" 14:36:04.159878 IP 192.168.120.49.6666 > 192.168.120.1.6666: UDP, length 3 "=> "
Ian Ray (2): net: net_up, net_down netconsole and networking co-existence
drivers/net/netconsole.c | 45 +++++++------------ include/net.h | 28 ++++-------- net/arp.c | 7 ++- net/arp.h | 1 + net/net.c | 111 ++++++++++++++++++++++++++++++++++------------- net/ping.c | 4 +- net/tftp.c | 4 -- net/wol.c | 1 - 8 files changed, 111 insertions(+), 90 deletions(-)
-- 2.10.1