systemd: enable KeepConfiguration= when running on network filesystem

This fix boot from NFS for systemd enabled systems. Previously
systemd-networkd dropped network configuration on exit from initrd even
if there're NFS mount.

[YOCTO #14708]

(From OE-Core rev: afb6b1625a43d64eba090f0f4c5e231d87df7833)

Signed-off-by: Pavel Zhukov <pavel.zhukov@huawei.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 254 insertions, 0 deletions

diff --git a/meta/recipes-core/systemd/systemd/0029-network-enable-KeepConfiguration-when-running-on-net.patch b/meta/recipes-core/systemd/systemd/0029-network-enable-KeepConfiguration-when-running-on-net.patch
new file mode 100644
index 0000000000..782b9645cb
--- /dev/null
+++ b/meta/recipes-core/systemd/systemd/0029-network-enable-KeepConfiguration-when-running-on-net.patch
@@ -0,0 +1,253 @@
+From 6f4e84126aaa4e26cb6865b054ea5ddebd3906e5 Mon Sep 17 00:00:00 2001
+From: Yu Watanabe <watanabe.yu+github@gmail.com>
+Date: Thu, 3 Feb 2022 12:14:19 +0900
+Subject: [PATCH] network: enable KeepConfiguration= when running on network
+ filesystem
+Cc: pavel@zhukoff.net
+
+Upstream-Status: Submitted [https://github.com/systemd/systemd/pull/22383]
+[YOCTO #14708]
+
+network-generator: rename DHCP_TYPE_DHCP -> DHCP_TYPE_DHCP4
+
+To emphasize this is DHCPv4. No behavior is changed.
+
+stat-util: introduce path_is_network_fs()
+
+network: enable KeepConfiguration= when running on network filesystem
+
+Also, set KeepConfiguration=dhcp-on-stop by default when running in
+initrd.
+
+Fixes #21967.
+---
+ man/systemd.network.xml                   |  6 +++--
+ src/basic/stat-util.c                     |  9 +++++++
+ src/basic/stat-util.h                     |  1 +
+ src/network/generator/network-generator.c |  4 ++--
+ src/network/generator/network-generator.h |  2 +-
+ src/network/networkd-manager.c            | 29 +++++++++++++++++++++++
+ src/network/networkd-manager.h            |  2 ++
+ src/network/networkd-network.c            | 12 ++++++----
+ src/network/test-networkd-conf.c          |  5 ++++
+ 9 files changed, 60 insertions(+), 10 deletions(-)
+
+diff --git a/man/systemd.network.xml b/man/systemd.network.xml
+index af431e4f2c..f90cff4cd6 100644
+--- a/man/systemd.network.xml
++++ b/man/systemd.network.xml
+@@ -944,8 +944,10 @@ Table=1234</programlisting></para>
+           lease expires. This is contrary to the DHCP specification, but may be the best choice if,
+           e.g., the root filesystem relies on this connection. The setting <literal>dhcp</literal>
+           implies <literal>dhcp-on-stop</literal>, and <literal>yes</literal> implies
+-          <literal>dhcp</literal> and <literal>static</literal>. Defaults to <literal>no</literal>.
+-          </para>
++          <literal>dhcp</literal> and <literal>static</literal>. Defaults to
++          <literal>dhcp-on-stop</literal> when <command>systemd-networkd</command> is running in
++          initrd, <literal>yes</literal> when the root filesystem is a network filesystem, and
++          <literal>no</literal> otherwise.</para>
+         </listitem>
+       </varlistentry>
+     </variablelist>
+diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c
+index efac7b002e..c2269844f8 100644
+--- a/src/basic/stat-util.c
++++ b/src/basic/stat-util.c
+@@ -249,6 +249,15 @@ int path_is_temporary_fs(const char *path) {
+         return is_temporary_fs(&s);
+ }
+ 
++int path_is_network_fs(const char *path) {
++        struct statfs s;
++
++        if (statfs(path, &s) < 0)
++                return -errno;
++
++        return is_network_fs(&s);
++}
++
+ int stat_verify_regular(const struct stat *st) {
+         assert(st);
+ 
+diff --git a/src/basic/stat-util.h b/src/basic/stat-util.h
+index a566114f7c..f7d2f12aa9 100644
+--- a/src/basic/stat-util.h
++++ b/src/basic/stat-util.h
+@@ -53,6 +53,7 @@ int fd_is_temporary_fs(int fd);
+ int fd_is_network_fs(int fd);
+ 
+ int path_is_temporary_fs(const char *path);
++int path_is_network_fs(const char *path);
+ 
+ /* Because statfs.t_type can be int on some architectures, we have to cast
+  * the const magic to the type, otherwise the compiler warns about
+diff --git a/src/network/generator/network-generator.c b/src/network/generator/network-generator.c
+index c081ec673c..063ad08d80 100644
+--- a/src/network/generator/network-generator.c
++++ b/src/network/generator/network-generator.c
+@@ -47,7 +47,7 @@ static const char * const dracut_dhcp_type_table[_DHCP_TYPE_MAX] = {
+         [DHCP_TYPE_OFF]     = "off",
+         [DHCP_TYPE_ON]      = "on",
+         [DHCP_TYPE_ANY]     = "any",
+-        [DHCP_TYPE_DHCP]    = "dhcp",
++        [DHCP_TYPE_DHCP4]   = "dhcp",
+         [DHCP_TYPE_DHCP6]   = "dhcp6",
+         [DHCP_TYPE_AUTO6]   = "auto6",
+         [DHCP_TYPE_EITHER6] = "either6",
+@@ -62,7 +62,7 @@ static const char * const networkd_dhcp_type_table[_DHCP_TYPE_MAX] = {
+         [DHCP_TYPE_OFF]     = "no",
+         [DHCP_TYPE_ON]      = "yes",
+         [DHCP_TYPE_ANY]     = "yes",
+-        [DHCP_TYPE_DHCP]    = "ipv4",
++        [DHCP_TYPE_DHCP4]   = "ipv4",
+         [DHCP_TYPE_DHCP6]   = "ipv6",
+         [DHCP_TYPE_AUTO6]   = "no",   /* TODO: enable other setting? */
+         [DHCP_TYPE_EITHER6] = "ipv6", /* TODO: enable other setting? */
+diff --git a/src/network/generator/network-generator.h b/src/network/generator/network-generator.h
+index dd0a58738b..0e0da2a57a 100644
+--- a/src/network/generator/network-generator.h
++++ b/src/network/generator/network-generator.h
+@@ -13,7 +13,7 @@ typedef enum DHCPType {
+         DHCP_TYPE_OFF,
+         DHCP_TYPE_ON,
+         DHCP_TYPE_ANY,
+-        DHCP_TYPE_DHCP,
++        DHCP_TYPE_DHCP4,
+         DHCP_TYPE_DHCP6,
+         DHCP_TYPE_AUTO6,
+         DHCP_TYPE_EITHER6,
+diff --git a/src/network/networkd-manager.c b/src/network/networkd-manager.c
+index 7e89366ae8..3261f289e9 100644
+--- a/src/network/networkd-manager.c
++++ b/src/network/networkd-manager.c
+@@ -398,6 +398,30 @@ static int signal_restart_callback(sd_event_source *s, const struct signalfd_sig
+         return sd_event_exit(sd_event_source_get_event(s), 0);
+ }
+ 
++static int manager_set_keep_configuration(Manager *m) {
++        int r;
++
++        assert(m);
++
++        if (in_initrd()) {
++                log_debug("Running in initrd, keep DHCPv4 addresses on stopping networkd by default.");
++                m->keep_configuration = KEEP_CONFIGURATION_DHCP_ON_STOP;
++                return 0;
++        }
++
++        r = path_is_network_fs("/");
++        if (r < 0)
++                return log_error_errno(r, "Failed to detect if root is network filesystem: %m");
++        if (r == 0) {
++                m->keep_configuration = _KEEP_CONFIGURATION_INVALID;
++                return 0;
++        }
++
++        log_debug("Running on network filesystem, enabling KeepConfiguration= by default.");
++        m->keep_configuration = KEEP_CONFIGURATION_YES;
++        return 0;
++}
++
+ int manager_setup(Manager *m) {
+         int r;
+ 
+@@ -453,6 +477,10 @@ int manager_setup(Manager *m) {
+         if (r < 0)
+                 return r;
+ 
++        r = manager_set_keep_configuration(m);
++        if (r < 0)
++                return r;
++
+         m->state_file = strdup("/run/systemd/netif/state");
+         if (!m->state_file)
+                 return -ENOMEM;
+@@ -468,6 +496,7 @@ int manager_new(Manager **ret, bool test_mode) {
+                 return -ENOMEM;
+ 
+         *m = (Manager) {
++                .keep_configuration = _KEEP_CONFIGURATION_INVALID,
+                 .test_mode = test_mode,
+                 .speed_meter_interval_usec = SPEED_METER_DEFAULT_TIME_INTERVAL,
+                 .online_state = _LINK_ONLINE_STATE_INVALID,
+diff --git a/src/network/networkd-manager.h b/src/network/networkd-manager.h
+index 36313589a3..86de529124 100644
+--- a/src/network/networkd-manager.h
++++ b/src/network/networkd-manager.h
+@@ -28,6 +28,8 @@ struct Manager {
+         Hashmap *polkit_registry;
+         int ethtool_fd;
+ 
++        KeepConfiguration keep_configuration;
++
+         bool test_mode;
+         bool enumerating;
+         bool dirty;
+diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
+index 3142be471f..edcd68d616 100644
+--- a/src/network/networkd-network.c
++++ b/src/network/networkd-network.c
+@@ -124,6 +124,7 @@ int network_verify(Network *network) {
+         int r;
+ 
+         assert(network);
++        assert(network->manager);
+         assert(network->filename);
+ 
+         if (net_match_is_empty(&network->match) && !network->conditions)
+@@ -248,10 +249,11 @@ int network_verify(Network *network) {
+         }
+ 
+         if (network->dhcp_critical >= 0) {
+-                if (network->keep_configuration >= 0)
+-                        log_warning("%s: Both KeepConfiguration= and deprecated CriticalConnection= are set. "
+-                                    "Ignoring CriticalConnection=.", network->filename);
+-                else if (network->dhcp_critical)
++                if (network->keep_configuration >= 0) {
++                        if (network->manager->keep_configuration < 0)
++                                log_warning("%s: Both KeepConfiguration= and deprecated CriticalConnection= are set. "
++                                            "Ignoring CriticalConnection=.", network->filename);
++                } else if (network->dhcp_critical)
+                         /* CriticalConnection=yes also preserve foreign static configurations. */
+                         network->keep_configuration = KEEP_CONFIGURATION_YES;
+                 else
+@@ -386,7 +388,7 @@ int network_load_one(Manager *manager, OrderedHashmap **networks, const char *fi
+                 .allmulticast = -1,
+                 .promiscuous = -1,
+ 
+-                .keep_configuration = _KEEP_CONFIGURATION_INVALID,
++                .keep_configuration = manager->keep_configuration,
+ 
+                 .dhcp_duid.type = _DUID_TYPE_INVALID,
+                 .dhcp_critical = -1,
+diff --git a/src/network/test-networkd-conf.c b/src/network/test-networkd-conf.c
+index 4b00a98086..5f1328e39c 100644
+--- a/src/network/test-networkd-conf.c
++++ b/src/network/test-networkd-conf.c
+@@ -6,6 +6,7 @@
+ #include "net-condition.h"
+ #include "networkd-address.h"
+ #include "networkd-conf.h"
++#include "networkd-manager.h"
+ #include "networkd-network.h"
+ #include "strv.h"
+ 
+@@ -166,11 +167,15 @@ static void test_config_parse_ether_addr(void) {
+ }
+ 
+ static void test_config_parse_address_one(const char *rvalue, int family, unsigned n_addresses, const union in_addr_union *u, unsigned char prefixlen) {
++        _cleanup_(manager_freep) Manager *manager = NULL;
+         _cleanup_(network_unrefp) Network *network = NULL;
+ 
++        assert_se(manager_new(&manager, /* test_mode = */ true) >= 0);
+         assert_se(network = new0(Network, 1));
+         network->n_ref = 1;
++        network->manager = manager;
+         assert_se(network->filename = strdup("hogehoge.network"));
++
+         assert_se(config_parse_match_ifnames("network", "filename", 1, "section", 1, "Name", 0, "*", &network->match.ifname, network) == 0);
+         assert_se(config_parse_address("network", "filename", 1, "section", 1, "Address", 0, rvalue, network, network) == 0);
+         assert_se(ordered_hashmap_size(network->addresses_by_section) == 1);
+-- 
+2.34.1
+
diff --git a/meta/recipes-core/systemd/systemd_250.3.bb b/meta/recipes-core/systemd/systemd_250.3.bb
index 7851c4c16a..0fe5fb7976 100644
--- a/meta/recipes-core/systemd/systemd_250.3.bb
+++ b/meta/recipes-core/systemd/systemd_250.3.bb
@@ -26,6 +26,7 @@ SRC_URI += "file://touchscreen.rules \
            file://0001-systemd.pc.in-use-ROOTPREFIX-without-suffixed-slash.patch \
            file://0001-test-parse-argument-Include-signal.h.patch \
            file://0001-mkdir-allow-to-create-directory-whose-path-contains-.patch \
+           file://0029-network-enable-KeepConfiguration-when-running-on-net.patch \
            "
 
 # patches needed by musl