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 #include "bus-protocol.h"
  28
  29 int introspect_begin(struct introspect *i) {
  30         assert(i);
  31
  32         zero(*i);
  33
  34         i->f = open_memstream(&i->introspection, &i->size);
  35         if (!i->f)
  36                 return -ENOMEM;
  37
  38         fputs(BUS_INTROSPECT_DOCTYPE
  39               "<node>\n", i->f);
  40
  41         return 0;
  42 }
  43
  44 int introspect_write_default_interfaces(struct introspect *i, bool object_manager) {
  45         assert(i);
  46
  47         fputs(BUS_INTROSPECT_INTERFACE_PEER
  48               BUS_INTROSPECT_INTERFACE_INTROSPECTABLE
  49               BUS_INTROSPECT_INTERFACE_PROPERTIES, i->f);
  50
  51         if (object_manager)
  52                 fputs(BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER, i->f);
  53
  54         return 0;
  55 }
  56
  57 int introspect_write_child_nodes(struct introspect *i, Set *s, const char *prefix) {
  58         char *node;
  59
  60         assert(i);
  61         assert(prefix);
  62
  63         while ((node = set_steal_first(s))) {
  64                 const char *e;
  65
  66                 e = object_path_startswith(node, prefix);
  67                 if (e && e[0])
  68                         fprintf(i->f, " <node name=\"%s\"/>\n", e);
  69
  70                 free(node);
  71         }
  72
  73         return 0;
  74 }
  75
  76 static void introspect_write_flags(struct introspect *i, int type, int flags) {
  77         if (flags & SD_BUS_VTABLE_DEPRECATED)
  78                 fputs("   <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
  79
  80         if (type == _SD_BUS_VTABLE_METHOD && flags & SD_BUS_VTABLE_METHOD_NO_REPLY)
  81                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
  82
  83         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {
  84                 if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  85                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  86                 else if (flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY)
  87                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  88         }
  89 }
  90
  91 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
  92         int r;
  93
  94         for (;;) {
  95                 size_t l;
  96
  97                 if (!*signature)
  98                         return 0;
  99
 100                 r = signature_element_length(signature, &l);
 101                 if (r < 0)
 102                         return r;
 103
 104                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 105
 106                 if (direction)
 107                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 108                 else
 109                         fputs("/>\n", i->f);
 110
 111                 signature += l;
 112         }
 113 }
 114
 115 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 116         assert(i);
 117         assert(v);
 118
 119         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 120
 121                 switch (v->type) {
 122
 123                 case _SD_BUS_VTABLE_START:
 124                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 125                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 126                         break;
 127
 128                 case _SD_BUS_VTABLE_METHOD:
 129                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 130                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 131                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 132                         introspect_write_flags(i, v->type, v->flags);
 133                         fputs("  </method>\n", i->f);
 134                         break;
 135
 136                 case _SD_BUS_VTABLE_PROPERTY:
 137                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 138                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 139                                 v->x.property.member,
 140                                 v->x.property.signature,
 141                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 142                         introspect_write_flags(i, v->type, v->flags);
 143                         fputs("  </property>\n", i->f);
 144                         break;
 145
 146                 case _SD_BUS_VTABLE_SIGNAL:
 147                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 148                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 149                         introspect_write_flags(i, v->type, v->flags);
 150                         fputs("  </signal>\n", i->f);
 151                         break;
 152                 }
 153
 154         }
 155
 156         return 0;
 157 }
 158
 159 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 160         sd_bus_message *q;
 161         int r;
 162
 163         assert(i);
 164         assert(m);
 165         assert(reply);
 166
 167         fputs("</node>\n", i->f);
 168         fflush(i->f);
 169
 170         if (ferror(i->f))
 171                 return -ENOMEM;
 172
 173         r = sd_bus_message_new_method_return(m, &q);
 174         if (r < 0)
 175                 return r;
 176
 177         r = sd_bus_message_append(q, "s", i->introspection);
 178         if (r < 0) {
 179                 sd_bus_message_unref(q);
 180                 return r;
 181         }
 182
 183         *reply = q;
 184         return 0;
 185 }
 186
 187 void introspect_free(struct introspect *i) {
 188         assert(i);
 189
 190         if (i->f)
 191                 fclose(i->f);
 192
 193         if (i->introspection)
 194                 free(i->introspection);
 195
 196         zero(*i);
 197 }