home: fix segfault when parsing arguments in PAM module

otherwise we might end up being faster than the unit itself, causing
unexpected fails, like:

```
testsuite.sh[297]: + systemctl start issue_14566_test
testsuite.sh[297]: + systemctl status issue_14566_test
testsuite.sh[304]: ● issue_14566_test.service - Issue 14566 Repro
testsuite.sh[304]:      Loaded: loaded (/etc/systemd/system/issue_14566_test.service; static; vendor preset: enabled)
testsuite.sh[304]:      Active: active (running) since Sat 2020-03-14 02:02:23 UTC; 417ms ago
testsuite.sh[304]:    Main PID: 301 ((repro.sh))
testsuite.sh[304]:       Tasks: 1 (limit: 535)
testsuite.sh[304]:      Memory: 180.0K
testsuite.sh[304]:         CPU: 122ms
testsuite.sh[304]:      CGroup: /system.slice/issue_14566_test.service
testsuite.sh[304]:              └─301 [(repro.sh)]
testsuite.sh[307]: ++ cat /leakedtestpid
testsuite.sh[307]: cat: /leakedtestpid: No such file or directory
testsuite.sh[297]: + leaked_pid=
```

man/sd_bus_get_fd.xml

@@ -22,6 +22,7 @@
 
   <refnamediv>
     <refname>sd_bus_get_fd</refname>
+    <refname>sd_bus_set_fd</refname>
     <refname>sd_bus_get_events</refname>
     <refname>sd_bus_get_timeout</refname>
 
@@ -37,6 +38,13 @@
         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
       </funcprototype>
 
+      <funcprototype>
+        <funcdef>int <function>sd_bus_set_fd</function></funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>int <parameter>input_fd</parameter></paramdef>
+        <paramdef>int <parameter>output_fd</parameter></paramdef>
+      </funcprototype>
+
       <funcprototype>
         <funcdef>int <function>sd_bus_get_events</function></funcdef>
         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
@@ -57,8 +65,13 @@
     object. This descriptor can be used with <citerefentry
     project='man-pages'><refentrytitle>poll</refentrytitle><manvolnum>3</manvolnum></citerefentry> or a similar
     function to wait for I/O events on the specified bus connection object. If the bus object was configured with the
-    <citerefentry><refentrytitle>sd_bus_set_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry> function, then
-    the <parameter>input_fd</parameter> file descriptor used in that call is returned.</para>
+    <function>sd_bus_set_fd()</function> function, then the <parameter>input_fd</parameter> file descriptor used in
+    that call is returned.</para>
+
+    <para><function>sd_bus_set_fd()</function> sets the file descriptors used to communicate from a message bus
+    object. Both <parameter>input_fd</parameter> and <parameter>output_fd</parameter> must be valid file descriptors.
+    The same file descriptor may be used as both the input and the output file descriptor. This function must be called
+    before the bus is started.</para>
 
     <para><function>sd_bus_get_events()</function> returns the I/O events to wait for, suitable for passing to
     <function>poll()</function> or a similar call. Returns a combination of <constant>POLLIN</constant>,
@@ -96,14 +109,17 @@
   <refsect1>
     <title>Return Value</title>
 
-    <para><function>sd_bus_get_fd()</function> returns the file descriptor used for communication, or a negative
-    <varname>errno</varname>-style error code on error.</para>
+    <para>On success, <function>sd_bus_get_fd()</function> returns the file descriptor used for communication. On failure,
+    it returns a negative errno-style error code.</para>
 
-    <para><function>sd_bus_get_events()</function> returns the I/O event mask to use for I/O event watching, or a
-    negative <varname>errno</varname>-style error code on error.</para>
+    <para>On success, <function>sd_bus_set_fd()</function> returns a non-negative integer. On failure, it returns a
+    negative errno-style error code.</para>
 
-    <para><function>sd_bus_get_timeout()</function> returns zero or positive on success, or a negative
-    <varname>errno</varname>-style error code on error.</para>
+    <para>On success, <function>sd_bus_get_events()</function> returns the I/O event mask to use for I/O event watching.
+    On failure, it returns a negative errno-style error code.</para>
+
+    <para>On success, <function>sd_bus_get_timeout()</function> returns a non-negative integer. On failure, it returns a
+    negative errno-style error code.</para>
 
     <refsect2>
       <title>Errors</title>
@@ -137,6 +153,19 @@
           <function>sd_bus_set_fd()</function>, which <function>sd_bus_get_fd()</function> cannot
           return.</para></listitem>
         </varlistentry>
+
+        <varlistentry>
+          <term><constant>-EBADF</constant></term>
+
+          <listitem><para>An invalid file descriptor was passed to <function>sd_bus_set_fd()</function>.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENOPKG</constant></term>
+
+          <listitem><para>The bus cannot be resolved.</para></listitem>
+        </varlistentry>
       </variablelist>
     </refsect2>
   </refsect1>
@@ -149,7 +178,6 @@
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
-      <citerefentry><refentrytitle>sd_bus_set_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd_bus_process</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

src/home/pam_systemd_home.c

@@ -36,7 +36,7 @@ static int parse_argv(
         for (i = 0; i < argc; i++) {
                 const char *v;
 
-                if ((v = startswith(argv[1], "suspend="))) {
+                if ((v = startswith(argv[i], "suspend="))) {
                         int k;
 
                         k = parse_boolean(v);

src/libsystemd/sd-netlink/netlink-types.c

@@ -543,9 +543,7 @@ static const NLType rtnl_link_types[] = {
         [IFLA_IFNAME]           = { .type = NETLINK_TYPE_STRING, .size = IFNAMSIZ - 1 },
         [IFLA_MTU]              = { .type = NETLINK_TYPE_U32 },
         [IFLA_LINK]             = { .type = NETLINK_TYPE_U32 },
-/*
-        [IFLA_QDISC],
-*/
+        [IFLA_QDISC]            = { .type = NETLINK_TYPE_STRING },
         [IFLA_STATS]            = { .size = sizeof(struct rtnl_link_stats) },
 /*
         [IFLA_COST],

src/network/networkctl.c

@@ -125,6 +125,7 @@ typedef struct LinkInfo {
         uint32_t max_mtu;
         uint32_t tx_queues;
         uint32_t rx_queues;
+        char *qdisc;
         char **alternative_names;
 
         union {
@@ -179,6 +180,7 @@ static const LinkInfo* link_info_array_free(LinkInfo *array) {
         for (unsigned i = 0; array && array[i].needs_freeing; i++) {
                 sd_device_unref(array[i].sd_device);
                 free(array[i].ssid);
+                free(array[i].qdisc);
                 strv_free(array[i].alternative_names);
         }
 
@@ -249,7 +251,7 @@ static int decode_netdev(sd_netlink_message *m, LinkInfo *info) {
 
 static int decode_link(sd_netlink_message *m, LinkInfo *info, char **patterns, bool matched_patterns[]) {
         _cleanup_strv_free_ char **altnames = NULL;
-        const char *name;
+        const char *name, *qdisc;
         int ifindex, r;
         uint16_t type;
 
@@ -333,6 +335,13 @@ static int decode_link(sd_netlink_message *m, LinkInfo *info, char **patterns, b
         else if (sd_netlink_message_read(m, IFLA_STATS, sizeof info->stats, &info->stats) >= 0)
                 info->has_stats = true;
 
+        r = sd_netlink_message_read_string(m, IFLA_QDISC, &qdisc);
+        if (r >= 0) {
+                info->qdisc = strdup(qdisc);
+                if (!info->qdisc)
+                        return log_oom();
+        }
+
         /* fill kind info */
         (void) decode_netdev(m, info);
 
@@ -1336,6 +1345,15 @@ static int link_status_one(
                         return table_log_add_error(r);
         }
 
+        if (info->qdisc) {
+                r = table_add_many(table,
+                                   TABLE_EMPTY,
+                                   TABLE_STRING, "QDisc:",
+                                   TABLE_STRING, info->qdisc);
+                if (r < 0)
+                        return table_log_add_error(r);
+        }
+
         if (streq_ptr(info->netdev_kind, "bridge")) {
                 r = table_add_many(table,
                                    TABLE_EMPTY,

test/TEST-47-ISSUE-14566/testsuite.sh

@@ -6,6 +6,7 @@ systemd-analyze log-level debug
 systemd-analyze log-target console
 
 systemctl start issue_14566_test
+sleep 1
 systemctl status issue_14566_test
 
 leaked_pid=$(cat /leakedtestpid)