src/libsystemd-bus/bus-introspect.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2013 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include "util.h"
  23 #include "sd-bus-protocol.h"
  24 #include "bus-introspect.h"
  25 #include "bus-signature.h"
  26 #include "bus-internal.h"
  27
  28 int introspect_begin(struct introspect *i) {
  29         assert(i);
  30
  31         zero(*i);
  32
  33         i->f = open_memstream(&i->introspection, &i->size);
  34         if (!i->f)
  35                 return -ENOMEM;
  36
  37         fputs(SD_BUS_INTROSPECT_DOCTYPE
  38               "<node>\n", i->f);
  39
  40         return 0;
  41 }
  42
  43 int introspect_write_default_interfaces(struct introspect *i, bool object_manager) {
  44         assert(i);
  45
  46         fputs(SD_BUS_INTROSPECT_INTERFACE_PEER
  47               SD_BUS_INTROSPECT_INTERFACE_INTROSPECTABLE
  48               SD_BUS_INTROSPECT_INTERFACE_PROPERTIES, i->f);
  49
  50         if (object_manager)
  51                 fputs(SD_BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER, i->f);
  52
  53         return 0;
  54 }
  55
  56 int introspect_write_child_nodes(struct introspect *i, Set *s, const char *prefix) {
  57         char *node;
  58
  59         assert(i);
  60         assert(prefix);
  61
  62         while ((node = set_steal_first(s))) {
  63                 const char *e;
  64
  65                 e = object_path_startswith(node, prefix);
  66                 if (e && e[0])
  67                         fprintf(i->f, " <node name=\"%s\"/>\n", e);
  68
  69                 free(node);
  70         }
  71
  72         return 0;
  73 }
  74
  75 static void introspect_write_flags(struct introspect *i, int type, int flags) {
  76         if (flags & SD_BUS_VTABLE_DEPRECATED)
  77                 fputs("   <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
  78
  79         if (type == _SD_BUS_VTABLE_METHOD && flags & SD_BUS_VTABLE_METHOD_NO_REPLY)
  80                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
  81
  82         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {
  83                 if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  84                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  85                 else if (flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY)
  86                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  87         }
  88 }
  89
  90 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
  91         int r;
  92
  93         for (;;) {
  94                 size_t l;
  95
  96                 if (!*signature)
  97                         return 0;
  98
  99                 r = signature_element_length(signature, &l);
 100                 if (r < 0)
 101                         return r;
 102
 103                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 104
 105                 if (direction)
 106                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 107                 else
 108                         fputs("/>\n", i->f);
 109
 110                 signature += l;
 111         }
 112 }
 113
 114 int introspect_write_interface(struct introspect *i, const char *interface, const sd_bus_vtable *v) {
 115         assert(i);
 116         assert(interface);
 117         assert(v);
 118
 119         fprintf(i->f, " <interface name=\"%s\">\n", interface);
 120
 121         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 122
 123                 switch (v->type) {
 124
 125                 case _SD_BUS_VTABLE_START:
 126                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 127                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 128                         break;
 129
 130                 case _SD_BUS_VTABLE_METHOD:
 131                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 132                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 133                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 134                         introspect_write_flags(i, v->type, v->flags);
 135                         fputs("  </method>\n", i->f);
 136                         break;
 137
 138                 case _SD_BUS_VTABLE_PROPERTY:
 139                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 140                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 141                                 v->x.property.member,
 142                                 v->x.property.signature,
 143                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 144                         introspect_write_flags(i, v->type, v->flags);
 145                         fputs("  </property>\n", i->f);
 146                         break;
 147
 148                 case _SD_BUS_VTABLE_SIGNAL:
 149                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 150                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 151                         introspect_write_flags(i, v->type, v->flags);
 152                         fputs("  </signal>\n", i->f);
 153                         break;
 154                 }
 155
 156         }
 157
 158         fputs(" </interface>\n", i->f);
 159         return 0;
 160 }
 161
 162 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 163         sd_bus_message *q;
 164         int r;
 165
 166         assert(i);
 167         assert(m);
 168         assert(reply);
 169
 170         fputs("</node>\n", i->f);
 171         fflush(i->f);
 172
 173         if (ferror(i->f))
 174                 return -ENOMEM;
 175
 176         r = sd_bus_message_new_method_return(bus, m, &q);
 177         if (r < 0)
 178                 return r;
 179
 180         r = sd_bus_message_append(q, "s", i->introspection);
 181         if (r < 0) {
 182                 sd_bus_message_unref(q);
 183                 return r;
 184         }
 185
 186         *reply = q;
 187         return 0;
 188 }
 189
 190 void introspect_free(struct introspect *i) {
 191         assert(i);
 192
 193         if (i->f)
 194                 fclose(i->f);
 195
 196         if (i->introspection)
 197                 free(i->introspection);
 198
 199         zero(*i);
 200 }