Merge ~vorlon/ubuntu/+source/ifupdown:ubuntu/devel into ubuntu/+source/ifupdown:ubuntu/devel

[Steve Langasek]

[Steve Langasek (vorlon)]

We will also need a corresponding upload of resolvconf, and we will also need to SRU systemd asap to remove its dhclient hook from the package, then add appropriate breaks in various places.

2a6b134... by Steve Langasek on 2020-04-22

add bug link

[Dimitri John Ledkov (xnox)]

code-review is good. Some minor comments.

will proceed to test builds & interactive testing.

review: Approve (code-review)

[Dimitri John Ledkov (xnox)]

Do we need any breaks/reaplaces on systemd? or like just drop conffile in systemd too?

[Steve Langasek (vorlon)]

On Thu, Apr 23, 2020 at 02:11:15PM -0000, Dimitri John Ledkov wrote:

> Do we need any breaks/reaplaces on systemd? or like just drop conffile in
> systemd too?

Yes we should, but we don't know the versions to use in the field until
systemd is uploaded.

>
> Diff comments:
>
> > diff --git a/debian/ifupdown.maintscript b/debian/ifupdown.maintscript
> > index 2203f84..11fd04c 100644
> > --- a/debian/ifupdown.maintscript
> > +++ b/debian/ifupdown.maintscript
> > @@ -7,3 +7,4 @@ rm_conffile /etc/init/network-interface-security.conf 0.8.25~ ifupdown
> > rm_conffile /etc/init/network-interface.conf 0.8.25~ ifupdown
> > rm_conffile /etc/network/if-up.d/upstart 0.8.29~ ifupdown
> > rm_conffile /etc/network/if-down.d/upstart 0.8.29~ ifupdown
> > +rm_conffile /etc/dhcp/dhclient-enter-hooks.d/resolved 0.8.35ubuntu2 systemd

> Given we do this, we need to also want systemd upload to remove the
> conffile there too, right?

Yes, definitely (and that determines what versions should be in the Breaks
field).

Unmerged commits

2a6b134... by Steve Langasek on 2020-04-22

add bug link

1528925... by Steve Langasek on 2020-04-22

suppress noise from cmp

509311f... by Steve Langasek on 2020-04-22

Make the exit hook also talk to resolved over dbus in the case that it is already running.

7c20bf9... by Steve Langasek on 2020-04-22

fix wrong shell quoting in state files

8dec9ea... by Steve Langasek on 2020-04-22

Split the hook into an enter and exit hook, using the enter hook only to undefine the hostile make_resolv_conf() and doing all the work in the exit hook.

add6bd1... by Steve Langasek on 2020-04-22

Make the hook write to a state file under /run/systemd/resolve/netif instead of feeding resolvconf.

20c8542... by Steve Langasek on 2020-04-22

resolved, not resolvconf

36e9f32... by Steve Langasek on 2020-04-22

Check whether the systemd-resolved unit is enabled before diverting resolv.conf handling, instead of just whether systemd-resolved binary is on the filesystem. LP: #1853164.

a64658f... by Steve Langasek on 2020-04-22

resolved, not resolvconf

c89d93b... by Steve Langasek on 2020-04-22

* Take over /etc/dhcp/dhclient-enter-hooks.d/resolved from systemd and move
  it to /etc/dhcp/dhclient-enter-hooks.d/ifupdown.
* Build-depend on dh-exec to support renaming files at install time.

diff --git a/debian/changelog b/debian/changelog
index 123923e..23379e9 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,21 @@
+ifupdown (0.8.35ubuntu2) UNRELEASED; urgency=medium
+
+  * Take over /etc/dhcp/dhclient-enter-hooks.d/resolved from systemd and
+    move it to /etc/dhcp/dhclient-enter-hooks.d/ifupdown.  LP: #1874337.
+  * Build-depend on dh-exec to support renaming files at install time.
+  * Check whether the systemd-resolved unit is enabled before diverting
+    resolv.conf handling, instead of just whether systemd-resolved binary is
+    on the filesystem.  LP: #1853164.
+  * Make the hook write to a state file under /run/systemd/resolve/netif
+    instead of feeding resolvconf.
+  * Split the hook into an enter and exit hook, using the enter hook only to
+    undefine the hostile make_resolv_conf() and doing all the work in the
+    exit hook.
+  * Make the exit hook also talk to resolved over dbus in the case that
+    it is already running.
+
+ -- Steve Langasek <[e-mail]>  Tue, 21 Apr 2020 21:58:37 -0700
+
 ifupdown (0.8.35ubuntu1) eoan; urgency=low
 
   * Merge from Debian unstable.  Remaining changes:
diff --git a/debian/control b/debian/control
index 71b2df6..50662d8 100644
--- a/debian/control
+++ b/debian/control
@@ -4,7 +4,7 @@ Priority: important
 Maintainer: Ubuntu Developers <[e-mail]>
 XSBC-Original-Maintainer: Guus Sliepen <[e-mail]>
 Standards-Version: 4.3.0
-Build-Depends: debhelper-compat (= 12)
+Build-Depends: debhelper-compat (= 12), dh-exec
 Vcs-Git: https://salsa.debian.org/debian/ifupdown.git
 Vcs-Browser: https://salsa.debian.org/debian/ifupdown
 Rules-Requires-Root: no
diff --git a/debian/ifupdown.dhclient-enter-hook b/debian/ifupdown.dhclient-enter-hook
new file mode 100755
index 0000000..ac75532
--- /dev/null
+++ b/debian/ifupdown.dhclient-enter-hook
@@ -0,0 +1,20 @@
+#
+# Script fragment to make dhclient supply nameserver information to resolved
+#
+
+# Tips:
+# * Be careful about changing the environment since this is sourced
+# * This script fragment uses bash features
+# * As of isc-dhcp-client 4.2 the "reason" (for running the script) can be one of the following.
+#   (Listed on man page:) MEDIUM(0) PREINIT(0)  BOUND(M)  RENEW(M)  REBIND(M)  REBOOT(M)         EXPIRE(D)  FAIL(D) RELEASE(D)  STOP(D) NBI(-) TIMEOUT(M)
+#   (Also used in master script:)                                                                                                                         ARPCHECK(0), ARPSEND(0)
+#   (Also used in master script:)   PREINIT6(0) BOUND6(M) RENEW6(M) REBIND6(M)        DEPREF6(0) EXPIRE6(D)         RELEASE6(D) STOP6(D)
+#   (0) = master script does not run make_resolv_conf
+#   (M) = master script runs make_resolv_conf
+#   (D) = master script downs interface
+#   (-) = master script does nothing with this
+
+if systemctl is-enabled systemd-resolved > /dev/null 2>&1; then
+        # For safety, undefine the nasty default make_resolv_conf()
+        make_resolv_conf() { : ; }
+ fi
diff --git a/debian/ifupdown.dhclient-exit-hook b/debian/ifupdown.dhclient-exit-hook
new file mode 100755
index 0000000..15d2740
--- /dev/null
+++ b/debian/ifupdown.dhclient-exit-hook
@@ -0,0 +1,110 @@
+#
+# Script fragment to make dhclient supply nameserver information to resolved
+#
+
+# Tips:
+# * Be careful about changing the environment since this is sourced
+# * This script fragment uses bash features
+# * As of isc-dhcp-client 4.2 the "reason" (for running the script) can be one of the following.
+#   (Listed on man page:) MEDIUM(0) PREINIT(0)  BOUND(M)  RENEW(M)  REBIND(M)  REBOOT(M)         EXPIRE(D)  FAIL(D) RELEASE(D)  STOP(D) NBI(-) TIMEOUT(M)
+#   (Also used in master script:)                                                                                                                         ARPCHECK(0), ARPSEND(0)
+#   (Also used in master script:)   PREINIT6(0) BOUND6(M) RENEW6(M) REBIND6(M)        DEPREF6(0) EXPIRE6(D)         RELEASE6(D) STOP6(D)
+#   (0) = master script does not run make_resolv_conf
+#   (M) = master script runs make_resolv_conf
+#   (D) = master script downs interface
+#   (-) = master script does nothing with this
+
+if systemctl is-enabled systemd-resolved > /dev/null 2>&1; then
+    local mystatedir statedir ifindex all_domain_servers
+
+    if [ ! "$interface" ] ; then
+        return
+    fi
+    ifindex=$(cat "/sys/class/net/$interface/ifindex")
+    if [ ! "$ifindex" ]; then
+        return
+    fi
+    mystatedir=/run/network
+    mkdir -p $mystatedir
+
+    statedir=/run/systemd/resolve/netif
+    mkdir -p $statedir
+
+    local oldstate="$(mktemp)"
+    # ignore errors due to nonexistent file
+    md5sum "$mystatedir/isc-dhcp-v4-$interface" "$mystatedir/isc-dhcp-v6-interface" > "$oldstate" 2> /dev/null || true
+
+    case "$reason" in
+      BOUND|RENEW|REBIND|REBOOT|TIMEOUT|BOUND6|RENEW6|REBIND6)
+        if [ -n "$new_domain_name_servers" ] ; then
+            cat <<EOF >"$mystatedir/isc-dhcp-v4-$interface"
+DNS="$new_domain_name_servers"
+EOF
+            if [ -n "$new_domain_name" ] || [ -n "$new_domain_search" ] ; then
+                cat <<EOF >>"$mystatedir/isc-dhcp-v4-$interface"
+DOMAINS="$new_domain_search $new_domain_name"
+EOF
+            fi
+        fi
+        if [ -n "$new_dhcp6_name_servers" ] ; then
+            cat <<EOF >"$mystatedir/isc-dhcp-v6-$interface"
+DNS6="$new_dhcp6_name_servers"
+EOF
+            if [ -n "$new_dhcp6_domain_search" ] ; then
+                cat <<EOF >>"$mystatedir/isc-dhcp-v6-$interface"
+DOMAINS6="$new_dhcp6_domain_search"
+EOF
+            fi
+        fi
+        ;;
+
+      EXPIRE|FAIL|RELEASE|STOP)
+        rm -f "/run/network/isc-dhcp-v4-$interface"
+        ;;
+      EXPIRE6|RELEASE6|STOP6)
+        rm -f "/run/network/isc-dhcp-v6-$interface"
+        ;;
+    esac
+
+    local newstate="$(mktemp)"
+    # ignore errors due to nonexistent file
+    md5sum "$mystatedir/isc-dhcp-v4-$interface" "$mystatedir/isc-dhcp-v6-$interface" > "$newstate" 2> /dev/null || true
+    if ! cmp "$oldstate" "$newstate" 2>/dev/null; then
+        local DNS DNS6 DOMAINS DOMAINS6
+        if [ -e "$mystatedir/isc-dhcp-v4-$interface" ]; then
+            . "$mystatedir/isc-dhcp-v4-$interface"
+        fi
+        if [ -e "$mystatedir/isc-dhcp-v6-$interface" ]; then
+            . "$mystatedir/isc-dhcp-v6-$interface"
+        fi
+
+        all_domain_servers="${DNS:+$DNS }$DNS6"
+        if [ -n "$all_domain_servers" ] ; then
+            cat <<EOF >"$statedir/$ifindex"
+# This is private data. Do not parse.
+LLMNR=yes
+MDNS=no
+SERVERS=$all_domain_servers
+DOMAINS=~. $DOMAINS $DOMAINS6
+EOF
+
+            # In addition to creating the state file (needed if we run before
+            # resolved is started), also feed the information directly to
+            # resolved.
+            if systemctl --quiet is-active systemd-resolved; then
+                resolvectl llmnr "$ifindex" yes
+                resolvectl mdns "$ifindex" no
+                resolvectl domain "$ifindex" ~. $DOMAINS $DOMAINS6
+                resolvectl dns "$ifindex" $all_domain_servers
+            fi
+        else
+            rm -f "$statedir/$ifindex"
+            if systemctl --quiet is-active systemd-resolved; then
+                resolvectl domain "$ifindex" ~.
+                resolvectl dns "$ifindex" ""
+            fi
+        fi
+
+        rm "$oldstate" "$newstate"
+    fi
+fi
diff --git a/debian/ifupdown.maintscript b/debian/ifupdown.maintscript
index 2203f84..11fd04c 100644
--- a/debian/ifupdown.maintscript
+++ b/debian/ifupdown.maintscript
@@ -7,3 +7,4 @@ rm_conffile /etc/init/network-interface-security.conf 0.8.25~ ifupdown
 rm_conffile /etc/init/network-interface.conf 0.8.25~ ifupdown
 rm_conffile /etc/network/if-up.d/upstart 0.8.29~ ifupdown
 rm_conffile /etc/network/if-down.d/upstart 0.8.29~ ifupdown
+rm_conffile /etc/dhcp/dhclient-enter-hooks.d/resolved 0.8.35ubuntu2 systemd
diff --git a/debian/install b/debian/install
old mode 100644
new mode 100755
index e8c928b..e288c72
--- a/debian/install
+++ b/debian/install
@@ -1,2 +1,5 @@
+#!/usr/bin/dh-exec
 contrib/* usr/share/doc/ifupdown/contrib
 debian/ifupdown-hotplug lib/udev
+debian/ifupdown.dhclient-enter-hook => etc/dhcp/dhclient-enter-hooks.d/ifupdown
+debian/ifupdown.dhclient-exit-hook => etc/dhcp/dhclient-exit-hooks.d/ifupdown