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                 if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN))
 125                         continue;
 126
 127                 switch (v->type) {
 128
 129                 case _SD_BUS_VTABLE_START:
 130                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 131                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 132                         break;
 133
 134                 case _SD_BUS_VTABLE_METHOD:
 135                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 136                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 137                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 138                         introspect_write_flags(i, v->type, v->flags);
 139                         fputs("  </method>\n", i->f);
 140                         break;
 141
 142                 case _SD_BUS_VTABLE_PROPERTY:
 143                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 144                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 145                                 v->x.property.member,
 146                                 v->x.property.signature,
 147                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 148                         introspect_write_flags(i, v->type, v->flags);
 149                         fputs("  </property>\n", i->f);
 150                         break;
 151
 152                 case _SD_BUS_VTABLE_SIGNAL:
 153                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 154                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 155                         introspect_write_flags(i, v->type, v->flags);
 156                         fputs("  </signal>\n", i->f);
 157                         break;
 158                 }
 159
 160         }
 161
 162         return 0;
 163 }
 164
 165 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 166         sd_bus_message *q;
 167         int r;
 168
 169         assert(i);
 170         assert(m);
 171         assert(reply);
 172
 173         fputs("</node>\n", i->f);
 174         fflush(i->f);
 175
 176         if (ferror(i->f))
 177                 return -ENOMEM;
 178
 179         r = sd_bus_message_new_method_return(m, &q);
 180         if (r < 0)
 181                 return r;
 182
 183         r = sd_bus_message_append(q, "s", i->introspection);
 184         if (r < 0) {
 185                 sd_bus_message_unref(q);
 186                 return r;
 187         }
 188
 189         *reply = q;
 190         return 0;
 191 }
 192
 193 void introspect_free(struct introspect *i) {
 194         assert(i);
 195
 196         if (i->f)
 197                 fclose(i->f);
 198
 199         if (i->introspection)
 200                 free(i->introspection);
 201
 202         zero(*i);
 203 }