network tc: qdisc parent add support to set ingress

```
$ network tc qdisc
qdisc noqueue 0: dev dummy99 root refcnt 2
qdisc ingress ffff: dev dummy99 parent ffff:fff1 ----------------

$ network cat dumm99.network
[Match]
Name=dummy99

[TrafficControlQueueingDiscipline]
Parent=ingress
```

3 files changed, 29 insertions, 16 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 692a686020..a23f0e6c23 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -2327,8 +2327,8 @@
       <varlistentry>
         <term><varname>Parent=</varname></term>
         <listitem>
-          <para>Specifies the parent Queueing Discipline (qdisc). Takes one of <literal>root</literal>
-          or <literal>clsact</literal>. Defaults to <literal>root</literal>.</para>
+          <para>Specifies the parent Queueing Discipline (qdisc). Takes one of <literal>root</literal>,
+          <literal>clsact</literal> or <literal>ingress</literal>. Defaults to <literal>root</literal>.</para>
         </listitem>
       </varlistentry>
 
diff --git a/src/network/tc/qdisc.c b/src/network/tc/qdisc.c
index 74b2b7a2c2..57e3025d7c 100644
--- a/src/network/tc/qdisc.c
+++ b/src/network/tc/qdisc.c
@@ -84,6 +84,7 @@ void qdisc_free(QDisc *qdisc) {
 
         network_config_section_free(qdisc->section);
 
+        free(qdisc->tca_kind);
         free(qdisc);
 }
 
@@ -116,6 +117,7 @@ static int qdisc_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
 int qdisc_configure(Link *link, QDisc *qdisc) {
         _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
         _cleanup_free_ char *tca_kind = NULL;
+        char *p;
         int r;
 
         assert(link);
@@ -131,12 +133,8 @@ int qdisc_configure(Link *link, QDisc *qdisc) {
         if (r < 0)
                 return log_link_error_errno(link, r, "Could not create tcm_parent message: %m");
 
-        if (qdisc->parent == TC_H_CLSACT) {
-                tca_kind = strdup("clsact");
-                if (!tca_kind)
-                        return log_oom();
-
-                r = sd_rtnl_message_set_qdisc_handle(req, TC_H_MAKE(TC_H_CLSACT, 0));
+        if (qdisc->handle != TC_H_UNSPEC) {
+                r = sd_rtnl_message_set_qdisc_handle(req, qdisc->handle);
                 if (r < 0)
                         return log_link_error_errno(link, r, "Could not set tcm_handle message: %m");
         }
@@ -171,8 +169,9 @@ int qdisc_configure(Link *link, QDisc *qdisc) {
                         return r;
         }
 
-        if (tca_kind) {
-                r = sd_netlink_message_append_string(req, TCA_KIND, tca_kind);
+        p = tca_kind ?:qdisc->tca_kind;
+        if (p) {
+                r = sd_netlink_message_append_string(req, TCA_KIND, p);
                 if (r < 0)
                         return log_link_error_errno(link, r, "Could not append TCA_KIND attribute: %m");
         }
@@ -218,10 +217,10 @@ int qdisc_section_verify(QDisc *qdisc, bool *has_root, bool *has_clsact) {
                                                  "Ignoring [TrafficControlQueueingDiscipline] section from line %u.",
                                                  qdisc->section->filename, qdisc->section->line);
                 *has_root = true;
-        } else if (qdisc->parent == TC_H_CLSACT) {
+        } else if (qdisc->parent == TC_H_CLSACT) { /* TC_H_CLSACT == TC_H_INGRESS */
                 if (*has_clsact)
                         return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
-                                                 "%s: More than one clsact TrafficControlQueueingDiscipline sections are defined. "
+                                                 "%s: More than one clsact or ingress TrafficControlQueueingDiscipline sections are defined. "
                                                  "Ignoring [TrafficControlQueueingDiscipline] section from line %u.",
                                                  qdisc->section->filename, qdisc->section->line);
                 *has_clsact = true;
@@ -255,17 +254,30 @@ int config_parse_tc_qdiscs_parent(
         if (r < 0)
                 return r;
 
-        if (streq(rvalue, "root"))
+        if (streq(rvalue, "root")) {
                 qdisc->parent = TC_H_ROOT;
-        else if (streq(rvalue, "clsact"))
+                qdisc->handle = TC_H_UNSPEC;
+        } else if (streq(rvalue, "clsact")) {
                 qdisc->parent = TC_H_CLSACT;
-        else {
+                qdisc->handle = TC_H_MAKE(TC_H_CLSACT, 0);
+        } else if (streq(rvalue, "ingress")) {
+                qdisc->parent = TC_H_INGRESS;
+                qdisc->handle = TC_H_MAKE(TC_H_INGRESS, 0);
+        } else {
                 log_syntax(unit, LOG_ERR, filename, line, r,
-                           "Failed to parse [QueueDiscs] 'Parent=', ignoring assignment: %s",
+                           "Failed to parse 'Parent=', ignoring assignment: %s",
                            rvalue);
                 return 0;
         }
 
+        if (streq(rvalue, "root"))
+                qdisc->tca_kind = mfree(qdisc->tca_kind);
+        else {
+                r = free_and_strdup(&qdisc->tca_kind, rvalue);
+                if (r < 0)
+                        return log_oom();
+        }
+
         qdisc = NULL;
 
         return 0;
diff --git a/src/network/tc/qdisc.h b/src/network/tc/qdisc.h
index 1d06dc53f4..cc68bdfaa7 100644
--- a/src/network/tc/qdisc.h
+++ b/src/network/tc/qdisc.h
@@ -21,6 +21,7 @@ typedef struct QDisc {
         uint32_t handle;
         uint32_t parent;
 
+        char *tca_kind;
         bool has_network_emulator:1;
         bool has_token_buffer_filter:1;
         bool has_stochastic_fairness_queueing:1;