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 sd_bus_vtable *v) {
 115         assert(i);
 116         assert(v);
 117
 118         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 119
 120                 switch (v->type) {
 121
 122                 case _SD_BUS_VTABLE_START:
 123                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 124                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 125                         break;
 126
 127                 case _SD_BUS_VTABLE_METHOD:
 128                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 129                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 130                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 131                         introspect_write_flags(i, v->type, v->flags);
 132                         fputs("  </method>\n", i->f);
 133                         break;
 134
 135                 case _SD_BUS_VTABLE_PROPERTY:
 136                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 137                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 138                                 v->x.property.member,
 139                                 v->x.property.signature,
 140                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 141                         introspect_write_flags(i, v->type, v->flags);
 142                         fputs("  </property>\n", i->f);
 143                         break;
 144
 145                 case _SD_BUS_VTABLE_SIGNAL:
 146                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 147                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 148                         introspect_write_flags(i, v->type, v->flags);
 149                         fputs("  </signal>\n", i->f);
 150                         break;
 151                 }
 152
 153         }
 154
 155         return 0;
 156 }
 157
 158 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 159         sd_bus_message *q;
 160         int r;
 161
 162         assert(i);
 163         assert(m);
 164         assert(reply);
 165
 166         fputs("</node>\n", i->f);
 167         fflush(i->f);
 168
 169         if (ferror(i->f))
 170                 return -ENOMEM;
 171
 172         r = sd_bus_message_new_method_return(bus, m, &q);
 173         if (r < 0)
 174                 return r;
 175
 176         r = sd_bus_message_append(q, "s", i->introspection);
 177         if (r < 0) {
 178                 sd_bus_message_unref(q);
 179                 return r;
 180         }
 181
 182         *reply = q;
 183         return 0;
 184 }
 185
 186 void introspect_free(struct introspect *i) {
 187         assert(i);
 188
 189         if (i->f)
 190                 fclose(i->f);
 191
 192         if (i->introspection)
 193                 free(i->introspection);
 194
 195         zero(*i);
 196 }