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Diffstat (limited to '')
-rw-r--r-- | src/libsystemd/sd-bus/bus-introspect.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/src/libsystemd/sd-bus/bus-introspect.c b/src/libsystemd/sd-bus/bus-introspect.c new file mode 100644 index 0000000..49236a8 --- /dev/null +++ b/src/libsystemd/sd-bus/bus-introspect.c @@ -0,0 +1,284 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include "bus-internal.h" +#include "bus-introspect.h" +#include "bus-objects.h" +#include "bus-protocol.h" +#include "bus-signature.h" +#include "fd-util.h" +#include "fileio.h" +#include "memory-util.h" +#include "string-util.h" + +#define BUS_INTROSPECT_DOCTYPE \ + "<!DOCTYPE node PUBLIC \"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN\"\n" \ + "\"https://www.freedesktop.org/standards/dbus/1.0/introspect.dtd\">\n" + +#define BUS_INTROSPECT_INTERFACE_PEER \ + " <interface name=\"org.freedesktop.DBus.Peer\">\n" \ + " <method name=\"Ping\"/>\n" \ + " <method name=\"GetMachineId\">\n" \ + " <arg type=\"s\" name=\"machine_uuid\" direction=\"out\"/>\n" \ + " </method>\n" \ + " </interface>\n" + +#define BUS_INTROSPECT_INTERFACE_INTROSPECTABLE \ + " <interface name=\"org.freedesktop.DBus.Introspectable\">\n" \ + " <method name=\"Introspect\">\n" \ + " <arg name=\"xml_data\" type=\"s\" direction=\"out\"/>\n" \ + " </method>\n" \ + " </interface>\n" + +#define BUS_INTROSPECT_INTERFACE_PROPERTIES \ + " <interface name=\"org.freedesktop.DBus.Properties\">\n" \ + " <method name=\"Get\">\n" \ + " <arg name=\"interface_name\" direction=\"in\" type=\"s\"/>\n" \ + " <arg name=\"property_name\" direction=\"in\" type=\"s\"/>\n" \ + " <arg name=\"value\" direction=\"out\" type=\"v\"/>\n" \ + " </method>\n" \ + " <method name=\"GetAll\">\n" \ + " <arg name=\"interface_name\" direction=\"in\" type=\"s\"/>\n" \ + " <arg name=\"props\" direction=\"out\" type=\"a{sv}\"/>\n" \ + " </method>\n" \ + " <method name=\"Set\">\n" \ + " <arg name=\"interface_name\" direction=\"in\" type=\"s\"/>\n" \ + " <arg name=\"property_name\" direction=\"in\" type=\"s\"/>\n" \ + " <arg name=\"value\" direction=\"in\" type=\"v\"/>\n" \ + " </method>\n" \ + " <signal name=\"PropertiesChanged\">\n" \ + " <arg type=\"s\" name=\"interface_name\"/>\n" \ + " <arg type=\"a{sv}\" name=\"changed_properties\"/>\n" \ + " <arg type=\"as\" name=\"invalidated_properties\"/>\n" \ + " </signal>\n" \ + " </interface>\n" + +#define BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER \ + " <interface name=\"org.freedesktop.DBus.ObjectManager\">\n" \ + " <method name=\"GetManagedObjects\">\n" \ + " <arg type=\"a{oa{sa{sv}}}\" name=\"object_paths_interfaces_and_properties\" direction=\"out\"/>\n" \ + " </method>\n" \ + " <signal name=\"InterfacesAdded\">\n" \ + " <arg type=\"o\" name=\"object_path\"/>\n" \ + " <arg type=\"a{sa{sv}}\" name=\"interfaces_and_properties\"/>\n" \ + " </signal>\n" \ + " <signal name=\"InterfacesRemoved\">\n" \ + " <arg type=\"o\" name=\"object_path\"/>\n" \ + " <arg type=\"as\" name=\"interfaces\"/>\n" \ + " </signal>\n" \ + " </interface>\n" + +int introspect_begin(struct introspect *i, bool trusted) { + assert(i); + + *i = (struct introspect) { + .trusted = trusted, + }; + + i->f = open_memstream_unlocked(&i->introspection, &i->size); + if (!i->f) + return -ENOMEM; + + fputs(BUS_INTROSPECT_DOCTYPE + "<node>\n", i->f); + + return 0; +} + +int introspect_write_default_interfaces(struct introspect *i, bool object_manager) { + assert(i); + + fputs(BUS_INTROSPECT_INTERFACE_PEER + BUS_INTROSPECT_INTERFACE_INTROSPECTABLE + BUS_INTROSPECT_INTERFACE_PROPERTIES, i->f); + + if (object_manager) + fputs(BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER, i->f); + + return 0; +} + +static int set_interface_name(struct introspect *intro, const char *interface_name) { + if (streq_ptr(intro->interface_name, interface_name)) + return 0; + + if (intro->interface_name) + fputs(" </interface>\n", intro->f); + + if (interface_name) + fprintf(intro->f, " <interface name=\"%s\">\n", interface_name); + + return free_and_strdup(&intro->interface_name, interface_name); +} + +int introspect_write_child_nodes(struct introspect *i, OrderedSet *s, const char *prefix) { + char *node; + + assert(i); + assert(prefix); + + assert_se(set_interface_name(i, NULL) >= 0); + + while ((node = ordered_set_steal_first(s))) { + const char *e; + + e = object_path_startswith(node, prefix); + if (e && e[0]) + fprintf(i->f, " <node name=\"%s\"/>\n", e); + + free(node); + } + + return 0; +} + +static void introspect_write_flags(struct introspect *i, int type, uint64_t flags) { + if (flags & SD_BUS_VTABLE_DEPRECATED) + fputs(" <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f); + + if (type == _SD_BUS_VTABLE_METHOD && (flags & SD_BUS_VTABLE_METHOD_NO_REPLY)) + fputs(" <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f); + + if (IN_SET(type, _SD_BUS_VTABLE_PROPERTY, _SD_BUS_VTABLE_WRITABLE_PROPERTY)) { + if (flags & SD_BUS_VTABLE_PROPERTY_EXPLICIT) + fputs(" <annotation name=\"org.freedesktop.systemd1.Explicit\" value=\"true\"/>\n", i->f); + + if (flags & SD_BUS_VTABLE_PROPERTY_CONST) + fputs(" <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"const\"/>\n", i->f); + else if (flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION) + fputs(" <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f); + else if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE)) + fputs(" <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f); + } + + if (!i->trusted && + IN_SET(type, _SD_BUS_VTABLE_METHOD, _SD_BUS_VTABLE_WRITABLE_PROPERTY) && + !(flags & SD_BUS_VTABLE_UNPRIVILEGED)) + fputs(" <annotation name=\"org.freedesktop.systemd1.Privileged\" value=\"true\"/>\n", i->f); +} + +/* Note that "names" is both an input and an output parameter. It initially points to the first argument name in a + NULL-separated list of strings, and is then advanced with each argument, and the resulting pointer is returned. */ +static int introspect_write_arguments(struct introspect *i, const char *signature, const char **names, const char *direction) { + int r; + + for (;;) { + size_t l; + + if (!*signature) + return 0; + + r = signature_element_length(signature, &l); + if (r < 0) + return r; + + fprintf(i->f, " <arg type=\"%.*s\"", (int) l, signature); + + if (**names != '\0') { + fprintf(i->f, " name=\"%s\"", *names); + *names += strlen(*names) + 1; + } + + if (direction) + fprintf(i->f, " direction=\"%s\"/>\n", direction); + else + fputs("/>\n", i->f); + + signature += l; + } +} + +int introspect_write_interface( + struct introspect *i, + const char *interface_name, + const sd_bus_vtable *v) { + + const sd_bus_vtable *vtable = ASSERT_PTR(v); + const char *names = ""; + int r; + + assert(i); + assert(interface_name); + + r = set_interface_name(i, interface_name); + if (r < 0) + return r; + + for (; v->type != _SD_BUS_VTABLE_END; v = bus_vtable_next(vtable, v)) { + + /* Ignore methods, signals and properties that are + * marked "hidden", but do show the interface + * itself */ + + if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN)) + continue; + + switch (v->type) { + + case _SD_BUS_VTABLE_START: + if (v->flags & SD_BUS_VTABLE_DEPRECATED) + fputs(" <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f); + break; + + case _SD_BUS_VTABLE_METHOD: + fprintf(i->f, " <method name=\"%s\">\n", v->x.method.member); + if (bus_vtable_has_names(vtable)) + names = strempty(v->x.method.names); + introspect_write_arguments(i, strempty(v->x.method.signature), &names, "in"); + introspect_write_arguments(i, strempty(v->x.method.result), &names, "out"); + introspect_write_flags(i, v->type, v->flags); + fputs(" </method>\n", i->f); + break; + + case _SD_BUS_VTABLE_PROPERTY: + case _SD_BUS_VTABLE_WRITABLE_PROPERTY: + fprintf(i->f, " <property name=\"%s\" type=\"%s\" access=\"%s\">\n", + v->x.property.member, + v->x.property.signature, + v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read"); + introspect_write_flags(i, v->type, v->flags); + fputs(" </property>\n", i->f); + break; + + case _SD_BUS_VTABLE_SIGNAL: + fprintf(i->f, " <signal name=\"%s\">\n", v->x.signal.member); + if (bus_vtable_has_names(vtable)) + names = strempty(v->x.signal.names); + introspect_write_arguments(i, strempty(v->x.signal.signature), &names, NULL); + introspect_write_flags(i, v->type, v->flags); + fputs(" </signal>\n", i->f); + break; + } + + } + + return 0; +} + +int introspect_finish(struct introspect *i, char **ret) { + int r; + + assert(i); + + assert_se(set_interface_name(i, NULL) >= 0); + + fputs("</node>\n", i->f); + + r = fflush_and_check(i->f); + if (r < 0) + return r; + + i->f = safe_fclose(i->f); + *ret = TAKE_PTR(i->introspection); + + return 0; +} + +void introspect_free(struct introspect *i) { + assert(i); + + /* Normally introspect_finish() does all the work, this is just a backup for error paths */ + + safe_fclose(i->f); + free(i->interface_name); + free(i->introspection); +} |