sd-bus: extend sd_bus_message_read_strv() to paths and signatures

It's rather convenient to be able to read all three types with this function.
Strictly speaking this change is not fully compatible, in case someone was
relying on sd_bus_message_read_strv() returning an error for anything except
"as", but I hope nobody was doing that.

diff --git a/man/sd_bus_message_read_strv.xml b/man/sd_bus_message_read_strv.xml
index a90ae84098395122209936ea8094155bf02cac1a..50580d86bcc5cd27bb6c7c68ebc202ef6d3e410f 100644 (file)
--- a/man/sd_bus_message_read_strv.xml
+++ b/man/sd_bus_message_read_strv.xml
@@ -36,11 +36,13 @@
   <refsect1>
     <title>Description</title>
 
-    <para><function>sd_bus_message_read_strv()</function> gives access to an array of strings in message
-    <parameter>m</parameter>. The "read pointer" in the message must be right before an array of strings. On
-    success, a pointer to the <constant>NULL</constant>-terminated array of strings is returned in the output
-    parameter <parameter>l</parameter>. Note that ownership of this array is transferred to the caller.
-    Hence, the caller is responsible for freeing this array and its contents.</para>
+    <para><function>sd_bus_message_read_strv()</function> gives access to an array of string-like items in
+    message <parameter>m</parameter>. The "read pointer" in the message must be right before an array of
+    strings (D-Bus type <literal>as</literal>), object paths (D-Bus type <literal>ao</literal>), or
+    signatures (D-Bus type <literal>ag</literal>). On success, a pointer to a
+    <constant>NULL</constant>-terminated array of strings is returned in the output parameter
+    <parameter>l</parameter>. Note that ownership of this array is transferred to the caller. Hence, the
+    caller is responsible for freeing this array and its contents.</para>
   </refsect1>
 
   <refsect1>
@@ -73,6 +75,13 @@
 
           <listitem><para>The message cannot be parsed.</para></listitem>
         </varlistentry>
+
+        <varlistentry>
+          <term><constant>-ENXIO</constant></term>
+
+          <listitem><para>The message "read pointer" is not right before an array of the appropriate type.
+          </para></listitem>
+        </varlistentry>
       </variablelist>
     </refsect2>
   </refsect1>

diff --git a/src/libsystemd/sd-bus/bus-message.c b/src/libsystemd/sd-bus/bus-message.c
index f358a8699e8de7dc8005ef4df2886943900d55d9..894d681260f3c233d011577cff02353191f20f5e 100644 (file)
--- a/src/libsystemd/sd-bus/bus-message.c
+++ b/src/libsystemd/sd-bus/bus-message.c
@@ -5587,17 +5587,26 @@ int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz) {
 }
 
 int bus_message_read_strv_extend(sd_bus_message *m, char ***l) {
-        const char *s;
+        char type;
+        const char *contents, *s;
         int r;
 
         assert(m);
         assert(l);
 
-        r = sd_bus_message_enter_container(m, 'a', "s");
+        r = sd_bus_message_peek_type(m, &type, &contents);
+        if (r < 0)
+                return r;
+
+        if (type != SD_BUS_TYPE_ARRAY || !STR_IN_SET(contents, "s", "o", "g"))
+                return -ENXIO;
+
+        r = sd_bus_message_enter_container(m, 'a', NULL);
         if (r <= 0)
                 return r;
 
-        while ((r = sd_bus_message_read_basic(m, 's', &s)) > 0) {
+        /* sd_bus_message_read_basic() does content validation for us. */
+        while ((r = sd_bus_message_read_basic(m, *contents, &s)) > 0) {
                 r = strv_extend(l, s);
                 if (r < 0)
                         return r;