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         if ((type == _SD_BUS_VTABLE_METHOD || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) && (flags & SD_BUS_VTABLE_UNPRIVILEGED))
  91                 fputs("   <annotation name=\"org.freedesktop.systemd1.Unprivileged\" value=\"true\"/>\n", i->f);
  92 }
  93
  94 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
  95         int r;
  96
  97         for (;;) {
  98                 size_t l;
  99
 100                 if (!*signature)
 101                         return 0;
 102
 103                 r = signature_element_length(signature, &l);
 104                 if (r < 0)
 105                         return r;
 106
 107                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 108
 109                 if (direction)
 110                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 111                 else
 112                         fputs("/>\n", i->f);
 113
 114                 signature += l;
 115         }
 116 }
 117
 118 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 119         assert(i);
 120         assert(v);
 121
 122         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 123
 124                 switch (v->type) {
 125
 126                 case _SD_BUS_VTABLE_START:
 127                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 128                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 129                         break;
 130
 131                 case _SD_BUS_VTABLE_METHOD:
 132                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 133                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 134                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 135                         introspect_write_flags(i, v->type, v->flags);
 136                         fputs("  </method>\n", i->f);
 137                         break;
 138
 139                 case _SD_BUS_VTABLE_PROPERTY:
 140                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 141                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 142                                 v->x.property.member,
 143                                 v->x.property.signature,
 144                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 145                         introspect_write_flags(i, v->type, v->flags);
 146                         fputs("  </property>\n", i->f);
 147                         break;
 148
 149                 case _SD_BUS_VTABLE_SIGNAL:
 150                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 151                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 152                         introspect_write_flags(i, v->type, v->flags);
 153                         fputs("  </signal>\n", i->f);
 154                         break;
 155                 }
 156
 157         }
 158
 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(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 }