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_EXPLICIT)
  85                         fputs("   <annotation name=\"org.freedesktop.systemd1.Explicit\" value=\"true\"/>\n", i->f);
  86
  87                 if (flags & SD_BUS_VTABLE_PROPERTY_CONST)
  88                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"const\"/>\n", i->f);
  89                 else if (flags & SD_BUS_VTABLE_PROPERTY_EMITS_INVALIDATION)
  90                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  91                 else if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  92                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  93         }
  94
  95         if (!i->trusted &&
  96             (type == _SD_BUS_VTABLE_METHOD || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) &&
  97             !(flags & SD_BUS_VTABLE_UNPRIVILEGED))
  98                 fputs("   <annotation name=\"org.freedesktop.systemd1.Privileged\" value=\"true\"/>\n", i->f);
  99 }
 100
 101 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
 102         int r;
 103
 104         for (;;) {
 105                 size_t l;
 106
 107                 if (!*signature)
 108                         return 0;
 109
 110                 r = signature_element_length(signature, &l);
 111                 if (r < 0)
 112                         return r;
 113
 114                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 115
 116                 if (direction)
 117                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 118                 else
 119                         fputs("/>\n", i->f);
 120
 121                 signature += l;
 122         }
 123 }
 124
 125 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 126         assert(i);
 127         assert(v);
 128
 129         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 130
 131                 /* Ignore methods, signals and properties that are
 132                  * marked "hidden", but do show the interface
 133                  * itself */
 134
 135                 if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN))
 136                         continue;
 137
 138                 switch (v->type) {
 139
 140                 case _SD_BUS_VTABLE_START:
 141                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 142                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 143                         break;
 144
 145                 case _SD_BUS_VTABLE_METHOD:
 146                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 147                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 148                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 149                         introspect_write_flags(i, v->type, v->flags);
 150                         fputs("  </method>\n", i->f);
 151                         break;
 152
 153                 case _SD_BUS_VTABLE_PROPERTY:
 154                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 155                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 156                                 v->x.property.member,
 157                                 v->x.property.signature,
 158                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 159                         introspect_write_flags(i, v->type, v->flags);
 160                         fputs("  </property>\n", i->f);
 161                         break;
 162
 163                 case _SD_BUS_VTABLE_SIGNAL:
 164                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 165                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 166                         introspect_write_flags(i, v->type, v->flags);
 167                         fputs("  </signal>\n", i->f);
 168                         break;
 169                 }
 170
 171         }
 172
 173         return 0;
 174 }
 175
 176 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 177         sd_bus_message *q;
 178         int r;
 179
 180         assert(i);
 181         assert(m);
 182         assert(reply);
 183
 184         fputs("</node>\n", i->f);
 185
 186         r = fflush_and_check(i->f);
 187         if (r < 0)
 188                 return r;
 189
 190         r = sd_bus_message_new_method_return(m, &q);
 191         if (r < 0)
 192                 return r;
 193
 194         r = sd_bus_message_append(q, "s", i->introspection);
 195         if (r < 0) {
 196                 sd_bus_message_unref(q);
 197                 return r;
 198         }
 199
 200         *reply = q;
 201         return 0;
 202 }
 203
 204 void introspect_free(struct introspect *i) {
 205         assert(i);
 206
 207         if (i->f)
 208                 fclose(i->f);
 209
 210         free(i->introspection);
 211         zero(*i);
 212 }