atftpd require UDPv4 socket

[hiroaki mizuguchi]

attfpd(source package: atfp) on Ubuntu 24.04 listen by atftpd.socket.

atfptd.socket bind UDPv6/IPv6. But this socket accept IPv4 and IPv6 both packets.

atftpd process require UDPv4/IPv4 listen socket.

# My workaround

atftpd.socket listen UDPv4/IPv4 socket.

/etc/systemd/system/atftpd.socket.d/workaround.conf
[Socket]
ListenDatagram=
ListenDatagram=0.0.0.0:69

# Package Infomation / System Infomation

root@bootserver:~# lsb_release -rd
No LSB modules are available.
Description: Ubuntu 24.04 LTS
Release: 24.04
root@bootserver:~# apt-cache policy atftpd
atftpd:
  Installed: 0.8.0-3ubuntu3
  Candidate: 0.8.0-3ubuntu3
  Version table:
 *** 0.8.0-3ubuntu3 500
        500 http://ftp.iij.ad.jp/pub/linux/ubuntu/archive noble/universe amd64 Packages
        100 /var/lib/dpkg/status

# Errorlog

This DEBUG log indicates that there is a problem with this code https://salsa.debian.org/debian/atftp/-/blob/0.8.0-3/tftpd.c?ref_type=tags#L728-736

May 11 01:24:53 bootserver systemd[1]: Started atftpd.service - Advanced TFTP Server.
May 11 01:24:53 bootserver atftpd[4551]: Advanced Trivial FTP server started (0.8.0)
May 11 01:24:53 bootserver atftpd[4551]: started by inetd or socket activated
May 11 01:24:53 bootserver atftpd[4551]: logging level: 7
May 11 01:24:53 bootserver atftpd[4551]: directory: /srv/tftp/
May 11 01:24:53 bootserver atftpd[4551]: user: nobody.nogroup
May 11 01:24:53 bootserver atftpd[4551]: log file: syslog
May 11 01:24:53 bootserver atftpd[4551]: not forcing to listen on local interfaces.
May 11 01:24:53 bootserver atftpd[4551]: server timeout: 300
May 11 01:24:53 bootserver atftpd[4551]: tftp retry timeout: 5
May 11 01:24:53 bootserver atftpd[4551]: maximum number of thread: 100
May 11 01:24:53 bootserver atftpd[4551]: option timeout: enabled
May 11 01:24:53 bootserver atftpd[4551]: option tzise: enabled
May 11 01:24:53 bootserver atftpd[4551]: option blksize: enabled
May 11 01:24:53 bootserver atftpd[4551]: option windowsize: enabled
May 11 01:24:53 bootserver atftpd[4551]: option multicast: enabled
May 11 01:24:53 bootserver atftpd[4551]: address range: 239.255.0.0-255
May 11 01:24:53 bootserver atftpd[4551]: port range: 1758
May 11 01:25:16 bootserver atftpd[4551]: socket may listen on any address, including broadcast
May 11 01:25:16 bootserver atftpd[4551]: bind: Cannot assign requested address
May 11 01:25:16 bootserver atftpd[4551]: Creating new socket: :::0
May 11 01:25:16 bootserver atftpd[4551]: Server thread exiting
May 11 01:26:36 bootserver atftpd[4551]: SIGTERM received, stopping threads and exiting.
May 11 01:26:36 bootserver atftpd[4551]: tftpd.c: 468: select: Interrupted system call
May 11 01:26:36 bootserver systemd[1]: Stopping atftpd.service - Advanced TFTP Server...
May 11 01:26:36 bootserver atftpd[4551]: atftpd terminating after 300 seconds
May 11 01:26:36 bootserver systemd[1]: atftpd.service: Deactivated successfully.

# GDB debuging

(gdb) n
734 in tftpd.c
(gdb) p to
$6 = {ss_family = 10, __ss_padding = "\000\000\036y\000\000\000\000\000\000\000\000\000\000\002", '\000' <repeats 102 times>,
  __ss_align = 0}
(gdb) p *(struct sockaddr_in*)&to
$8 = {sin_family = 10, sin_port = 0, sin_addr = {s_addr = 31006}, sin_zero = "\000\000\000\000\000\000\000"}
(gdb) p *(struct sockaddr_in6*)&to
$9 = {sin6_family = 10, sin6_port = 0, sin6_flowinfo = 31006, sin6_addr = {__in6_u = {
      __u6_addr8 = "\000\000\000\000\000\000\000\000\002\000\000\000\000\000\000", __u6_addr16 = {0, 0, 0, 0, 2, 0, 0, 0},
      __u6_addr32 = {0, 0, 2, 0}}}, sin6_scope_id = 0}
(gdb) quit

root@bootserver:~# lsof -p 7298
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
in.tftpd 7298 atftpd cwd DIR 252,1 4096 2 /
in.tftpd 7298 atftpd rtd DIR 252,1 4096 2 /
in.tftpd 7298 atftpd txt REG 252,1 81040 3014777 /usr/sbin/atftpd
in.tftpd 7298 atftpd mem REG 252,1 2125328 3020752 /usr/lib/x86_64-linux-gnu/libc.so.6
in.tftpd 7298 atftpd mem REG 252,1 182944 3026891 /usr/lib/x86_64-linux-gnu/libgcc_s.so.1
in.tftpd 7298 atftpd mem REG 252,1 625344 3027015 /usr/lib/x86_64-linux-gnu/libpcre2-8.so.0.11.2
in.tftpd 7298 atftpd mem REG 252,1 44064 3047322 /usr/lib/x86_64-linux-gnu/libwrap.so.0.7.6
in.tftpd 7298 atftpd mem REG 252,1 236616 3020748 /usr/lib/x86_64-linux-gnu/ld-linux-x86-64.so.2
in.tftpd 7298 atftpd 0u IPv6 63411 0t0 UDP *:tftp
in.tftpd 7298 atftpd 1u IPv6 63411 0t0 UDP *:tftp
in.tftpd 7298 atftpd 2u IPv6 63411 0t0 UDP *:tftp
in.tftpd 7298 atftpd 3u unix 0xffff9d588ed85800 0t0 63415 type=DGRAM (CONNECTED)
in.tftpd 7298 atftpd 4u sock 0,8 0t0 15261 protocol: UDPv6