src/libsystemd/sd-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 "bus-introspect.h"
  24 #include "bus-signature.h"
  25 #include "bus-internal.h"
  26 #include "bus-protocol.h"
  27
  28 int introspect_begin(struct introspect *i, bool trusted) {
  29         assert(i);
  30
  31         zero(*i);
  32         i->trusted = trusted;
  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_CONST)
  85                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"const\"/>\n", i->f);
  86                 else if (flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)
  87                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  88                 else if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  89                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  90         }
  91
  92         if (!i->trusted &&
  93             (type == _SD_BUS_VTABLE_METHOD || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) &&
  94             !(flags & SD_BUS_VTABLE_UNPRIVILEGED))
  95                 fputs("   <annotation name=\"org.freedesktop.systemd1.Privileged\" value=\"true\"/>\n", i->f);
  96 }
  97
  98 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
  99         int r;
 100
 101         for (;;) {
 102                 size_t l;
 103
 104                 if (!*signature)
 105                         return 0;
 106
 107                 r = signature_element_length(signature, &l);
 108                 if (r < 0)
 109                         return r;
 110
 111                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 112
 113                 if (direction)
 114                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 115                 else
 116                         fputs("/>\n", i->f);
 117
 118                 signature += l;
 119         }
 120 }
 121
 122 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 123         assert(i);
 124         assert(v);
 125
 126         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 127
 128                 /* Ignore methods, signals and properties that are
 129                  * marked "hidden", but do show the interface
 130                  * itself */
 131
 132                 if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN))
 133                         continue;
 134
 135                 switch (v->type) {
 136
 137                 case _SD_BUS_VTABLE_START:
 138                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 139                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 140                         break;
 141
 142                 case _SD_BUS_VTABLE_METHOD:
 143                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 144                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 145                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 146                         introspect_write_flags(i, v->type, v->flags);
 147                         fputs("  </method>\n", i->f);
 148                         break;
 149
 150                 case _SD_BUS_VTABLE_PROPERTY:
 151                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 152                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 153                                 v->x.property.member,
 154                                 v->x.property.signature,
 155                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 156                         introspect_write_flags(i, v->type, v->flags);
 157                         fputs("  </property>\n", i->f);
 158                         break;
 159
 160                 case _SD_BUS_VTABLE_SIGNAL:
 161                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 162                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 163                         introspect_write_flags(i, v->type, v->flags);
 164                         fputs("  </signal>\n", i->f);
 165                         break;
 166                 }
 167
 168         }
 169
 170         return 0;
 171 }
 172
 173 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 174         sd_bus_message *q;
 175         int r;
 176
 177         assert(i);
 178         assert(m);
 179         assert(reply);
 180
 181         fputs("</node>\n", i->f);
 182         fflush(i->f);
 183
 184         if (ferror(i->f))
 185                 return -ENOMEM;
 186
 187         r = sd_bus_message_new_method_return(m, &q);
 188         if (r < 0)
 189                 return r;
 190
 191         r = sd_bus_message_append(q, "s", i->introspection);
 192         if (r < 0) {
 193                 sd_bus_message_unref(q);
 194                 return r;
 195         }
 196
 197         *reply = q;
 198         return 0;
 199 }
 200
 201 void introspect_free(struct introspect *i) {
 202         assert(i);
 203
 204         if (i->f)
 205                 fclose(i->f);
 206
 207         if (i->introspection)
 208                 free(i->introspection);
 209
 210         zero(*i);
 211 }