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, bool trusted) {
  30         assert(i);
  31
  32         zero(*i);
  33         i->trusted = trusted;
  34
  35         i->f = open_memstream(&i->introspection, &i->size);
  36         if (!i->f)
  37                 return -ENOMEM;
  38
  39         fputs(BUS_INTROSPECT_DOCTYPE
  40               "<node>\n", i->f);
  41
  42         return 0;
  43 }
  44
  45 int introspect_write_default_interfaces(struct introspect *i, bool object_manager) {
  46         assert(i);
  47
  48         fputs(BUS_INTROSPECT_INTERFACE_PEER
  49               BUS_INTROSPECT_INTERFACE_INTROSPECTABLE
  50               BUS_INTROSPECT_INTERFACE_PROPERTIES, i->f);
  51
  52         if (object_manager)
  53                 fputs(BUS_INTROSPECT_INTERFACE_OBJECT_MANAGER, i->f);
  54
  55         return 0;
  56 }
  57
  58 int introspect_write_child_nodes(struct introspect *i, Set *s, const char *prefix) {
  59         char *node;
  60
  61         assert(i);
  62         assert(prefix);
  63
  64         while ((node = set_steal_first(s))) {
  65                 const char *e;
  66
  67                 e = object_path_startswith(node, prefix);
  68                 if (e && e[0])
  69                         fprintf(i->f, " <node name=\"%s\"/>\n", e);
  70
  71                 free(node);
  72         }
  73
  74         return 0;
  75 }
  76
  77 static void introspect_write_flags(struct introspect *i, int type, int flags) {
  78         if (flags & SD_BUS_VTABLE_DEPRECATED)
  79                 fputs("   <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
  80
  81         if (type == _SD_BUS_VTABLE_METHOD && (flags & SD_BUS_VTABLE_METHOD_NO_REPLY))
  82                 fputs("   <annotation name=\"org.freedesktop.DBus.Method.NoReply\" value=\"true\"/>\n", i->f);
  83
  84         if (type == _SD_BUS_VTABLE_PROPERTY || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) {
  85                 if (!(flags & SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE))
  86                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"false\"/>\n", i->f);
  87                 else if (flags & SD_BUS_VTABLE_PROPERTY_INVALIDATE_ONLY)
  88                         fputs("   <annotation name=\"org.freedesktop.DBus.Property.EmitsChangedSignal\" value=\"invalidates\"/>\n", i->f);
  89         }
  90
  91         if (!i->trusted &&
  92             (type == _SD_BUS_VTABLE_METHOD || type == _SD_BUS_VTABLE_WRITABLE_PROPERTY) &&
  93             !(flags & SD_BUS_VTABLE_UNPRIVILEGED))
  94                 fputs("   <annotation name=\"org.freedesktop.systemd1.Privileged\" value=\"true\"/>\n", i->f);
  95 }
  96
  97 static int introspect_write_arguments(struct introspect *i, const char *signature, const char *direction) {
  98         int r;
  99
 100         for (;;) {
 101                 size_t l;
 102
 103                 if (!*signature)
 104                         return 0;
 105
 106                 r = signature_element_length(signature, &l);
 107                 if (r < 0)
 108                         return r;
 109
 110                 fprintf(i->f, "   <arg type=\"%.*s\"", (int) l, signature);
 111
 112                 if (direction)
 113                         fprintf(i->f, " direction=\"%s\"/>\n", direction);
 114                 else
 115                         fputs("/>\n", i->f);
 116
 117                 signature += l;
 118         }
 119 }
 120
 121 int introspect_write_interface(struct introspect *i, const sd_bus_vtable *v) {
 122         assert(i);
 123         assert(v);
 124
 125         for (; v->type != _SD_BUS_VTABLE_END; v++) {
 126
 127                 /* Ignore methods, signals and properties that are
 128                  * marked "hidden", but do show the interface
 129                  * itself */
 130
 131                 if (v->type != _SD_BUS_VTABLE_START && (v->flags & SD_BUS_VTABLE_HIDDEN))
 132                         continue;
 133
 134                 switch (v->type) {
 135
 136                 case _SD_BUS_VTABLE_START:
 137                         if (v->flags & SD_BUS_VTABLE_DEPRECATED)
 138                                 fputs("  <annotation name=\"org.freedesktop.DBus.Deprecated\" value=\"true\"/>\n", i->f);
 139                         break;
 140
 141                 case _SD_BUS_VTABLE_METHOD:
 142                         fprintf(i->f, "  <method name=\"%s\">\n", v->x.method.member);
 143                         introspect_write_arguments(i, strempty(v->x.method.signature), "in");
 144                         introspect_write_arguments(i, strempty(v->x.method.result), "out");
 145                         introspect_write_flags(i, v->type, v->flags);
 146                         fputs("  </method>\n", i->f);
 147                         break;
 148
 149                 case _SD_BUS_VTABLE_PROPERTY:
 150                 case _SD_BUS_VTABLE_WRITABLE_PROPERTY:
 151                         fprintf(i->f, "  <property name=\"%s\" type=\"%s\" access=\"%s\">\n",
 152                                 v->x.property.member,
 153                                 v->x.property.signature,
 154                                 v->type == _SD_BUS_VTABLE_WRITABLE_PROPERTY ? "readwrite" : "read");
 155                         introspect_write_flags(i, v->type, v->flags);
 156                         fputs("  </property>\n", i->f);
 157                         break;
 158
 159                 case _SD_BUS_VTABLE_SIGNAL:
 160                         fprintf(i->f, "  <signal name=\"%s\">\n", v->x.signal.member);
 161                         introspect_write_arguments(i, strempty(v->x.signal.signature), NULL);
 162                         introspect_write_flags(i, v->type, v->flags);
 163                         fputs("  </signal>\n", i->f);
 164                         break;
 165                 }
 166
 167         }
 168
 169         return 0;
 170 }
 171
 172 int introspect_finish(struct introspect *i, sd_bus *bus, sd_bus_message *m, sd_bus_message **reply) {
 173         sd_bus_message *q;
 174         int r;
 175
 176         assert(i);
 177         assert(m);
 178         assert(reply);
 179
 180         fputs("</node>\n", i->f);
 181         fflush(i->f);
 182
 183         if (ferror(i->f))
 184                 return -ENOMEM;
 185
 186         r = sd_bus_message_new_method_return(m, &q);
 187         if (r < 0)
 188                 return r;
 189
 190         r = sd_bus_message_append(q, "s", i->introspection);
 191         if (r < 0) {
 192                 sd_bus_message_unref(q);
 193                 return r;
 194         }
 195
 196         *reply = q;
 197         return 0;
 198 }
 199
 200 void introspect_free(struct introspect *i) {
 201         assert(i);
 202
 203         if (i->f)
 204                 fclose(i->f);
 205
 206         if (i->introspection)
 207                 free(i->introspection);
 208
 209         zero(*i);
 210 }