Bug#1027447: qemu: path to qemu-bridge-helper broken in qemu-system-* manuals

[наб]

Source: qemu
Version: 1:5.2+dfsg-11+deb11u2
Severity: normal

Dear Maintainer,

Quoth qemu-system-x86_64 (and -s390x):
-netdev tap,id=id[,fd=h][,ifname=name][,script=file][,downscript=dfile][,br=bridge][,helper=helper]
Configure a host TAP network backend with ID id.

Use the network script file to configure it and the network script dfile to deconfigure it. If name is not provided, the OS automatically provides one.
The default network configure script is /etc/qemu-ifup and the default network deconfigure script is /etc/qemu-ifdown. Use script=no or downscript=no to
disable script execution.

If running QEMU as an unprivileged user, use the network helper to configure the TAP interface and attach it to the bridge. The default network helper
executable is /path/to/qemu-bridge-helper and the default bridge device is br0.

fd=h can be used to specify the handle of an already opened host TAP interface.

Examples:

#launch a QEMU instance with the default network script
qemu-system-x86_64 linux.img -nic tap

#launch a QEMU instance with two NICs, each one connected
#to a TAP device
qemu-system-x86_64 linux.img \
-netdev tap,id=nd0,ifname=tap0 -device e1000,netdev=nd0 \
-netdev tap,id=nd1,ifname=tap1 -device rtl8139,netdev=nd1

#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
qemu-system-x86_64 linux.img -device virtio-net-pci,netdev=n1 \
-netdev tap,id=n1,"helper=/path/to/qemu-bridge-helper"

-netdev bridge,id=id[,br=bridge][,helper=helper]
Connect a host TAP network interface to a host bridge device.

Use the network helper helper to configure the TAP interface and attach it to the bridge. The default network helper executable is
/path/to/qemu-bridge-helper and the default bridge device is br0.

Examples:

#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge br0
qemu-system-x86_64 linux.img -netdev bridge,id=n1 -device virtio-net,netdev=n1

#launch a QEMU instance with the default network helper to
#connect a TAP device to bridge qemubr0
qemu-system-x86_64 linux.img -netdev bridge,br=qemubr0,id=n1 -device virtio-net,netdev=n1

And, well, if the default executable is /path/to/qemu-bridge-helper then
it's broken, because that's /usr/lib/qemu/qemu-bridge-helper,
according to dpkg -S.

If it's not then the manual's broken, because it doesn't match the
actual path.

Best,
наб

-- System Information:
Debian Release: 11.6
APT prefers stable-updates
APT policy: (500, 'stable-updates'), (500, 'stable-security'), (500, 'stable-debug'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 5.10.0-20-amd64 (SMP w/24 CPU threads)
Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_FIRMWARE_WORKAROUND, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8), LANGUAGE=en_GB:en
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

[Michael Tokarev]

Control: severity -1 minor
Control: tag -1 + confirmed upstream

31.12.2022 19:42, наб пишет:

> Source: qemu
> Version: 1:5.2+dfsg-11+deb11u2
> Severity: normal
>
> Dear Maintainer,
>
> Quoth qemu-system-x86_64 (and -s390x):

> ... The default network helper executable is /path/to/qemu-bridge-helper ...

Indeed it is. No one bothered to fix that in the doc so far.
It's easy to find it though (in recent qemu it is in /usr/libexec/qemu/).

/mjt