src/libsystemd/sd-bus/bus-message.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <byteswap.h>
   5 #include <stdbool.h>
   6 #include <sys/socket.h>
   7
   8 #include "sd-bus.h"
   9
  10 #include "bus-creds.h"
  11 #include "bus-protocol.h"
  12 #include "macro.h"
  13 #include "time-util.h"
  14
  15 struct bus_container {
  16         char enclosing;
  17         bool need_offsets:1;
  18
  19         /* Indexes into the signature  string */
  20         unsigned index, saved_index;
  21         char *signature;
  22
  23         size_t before, begin, end;
  24
  25         /* dbus1: pointer to the array size value, if this is a value */
  26         uint32_t *array_size;
  27
  28         /* gvariant: list of offsets to end of children if this is struct/dict entry/array */
  29         size_t *offsets, n_offsets, offsets_allocated, offset_index;
  30         size_t item_size;
  31
  32         char *peeked_signature;
  33 };
  34
  35 struct bus_body_part {
  36         struct bus_body_part *next;
  37         void *data;
  38         void *mmap_begin;
  39         size_t size;
  40         size_t mapped;
  41         size_t allocated;
  42         uint64_t memfd_offset;
  43         int memfd;
  44         bool free_this:1;
  45         bool munmap_this:1;
  46         bool sealed:1;
  47         bool is_zero:1;
  48 };
  49
  50 struct sd_bus_message {
  51         /* Caveat: a message can be referenced in two different ways: the main (user-facing) way will also
  52          * pin the bus connection object the message is associated with. The secondary way ("queued") is used
  53          * when a message is in the read or write queues of the bus connection object, which will not pin the
  54          * bus connection object. This is necessary so that we don't have to have a pair of cyclic references
  55          * between a message that is queued and its connection: as soon as a message is only referenced by
  56          * the connection (by means of being queued) and the connection itself has no other references it
  57          * will be freed. */
  58
  59         unsigned n_ref;     /* Counter of references that pin the connection */
  60         unsigned n_queued;  /* Counter of references that do not pin the connection */
  61
  62         sd_bus *bus;
  63
  64         uint64_t reply_cookie;
  65
  66         const char *path;
  67         const char *interface;
  68         const char *member;
  69         const char *destination;
  70         const char *sender;
  71
  72         sd_bus_error error;
  73
  74         sd_bus_creds creds;
  75
  76         usec_t monotonic;
  77         usec_t realtime;
  78         uint64_t seqnum;
  79         int64_t priority;
  80         uint64_t verify_destination_id;
  81
  82         bool sealed:1;
  83         bool dont_send:1;
  84         bool allow_fds:1;
  85         bool free_header:1;
  86         bool free_fds:1;
  87         bool poisoned:1;
  88
  89         /* The first and last bytes of the message */
  90         struct bus_header *header;
  91         void *footer;
  92
  93         /* How many bytes are accessible in the above pointers */
  94         size_t header_accessible;
  95         size_t footer_accessible;
  96
  97         size_t fields_size;
  98         size_t body_size;
  99         size_t user_body_size;
 100
 101         struct bus_body_part body;
 102         struct bus_body_part *body_end;
 103         unsigned n_body_parts;
 104
 105         size_t rindex;
 106         struct bus_body_part *cached_rindex_part;
 107         size_t cached_rindex_part_begin;
 108
 109         uint32_t n_fds;
 110         int *fds;
 111
 112         struct bus_container root_container, *containers;
 113         size_t n_containers;
 114         size_t containers_allocated;
 115
 116         struct iovec *iovec;
 117         struct iovec iovec_fixed[2];
 118         unsigned n_iovec;
 119
 120         char *peeked_signature;
 121
 122         /* If set replies to this message must carry the signature
 123          * specified here to successfully seal. This is initialized
 124          * from the vtable data */
 125         const char *enforced_reply_signature;
 126
 127         usec_t timeout;
 128
 129         size_t header_offsets[_BUS_MESSAGE_HEADER_MAX];
 130         unsigned n_header_offsets;
 131 };
 132
 133 static inline bool BUS_MESSAGE_NEED_BSWAP(sd_bus_message *m) {
 134         return m->header->endian != BUS_NATIVE_ENDIAN;
 135 }
 136
 137 static inline uint16_t BUS_MESSAGE_BSWAP16(sd_bus_message *m, uint16_t u) {
 138         return BUS_MESSAGE_NEED_BSWAP(m) ? bswap_16(u) : u;
 139 }
 140
 141 static inline uint32_t BUS_MESSAGE_BSWAP32(sd_bus_message *m, uint32_t u) {
 142         return BUS_MESSAGE_NEED_BSWAP(m) ? bswap_32(u) : u;
 143 }
 144
 145 static inline uint64_t BUS_MESSAGE_BSWAP64(sd_bus_message *m, uint64_t u) {
 146         return BUS_MESSAGE_NEED_BSWAP(m) ? bswap_64(u) : u;
 147 }
 148
 149 static inline uint64_t BUS_MESSAGE_COOKIE(sd_bus_message *m) {
 150         if (m->header->version == 2)
 151                 return BUS_MESSAGE_BSWAP64(m, m->header->dbus2.cookie);
 152
 153         return BUS_MESSAGE_BSWAP32(m, m->header->dbus1.serial);
 154 }
 155
 156 static inline size_t BUS_MESSAGE_SIZE(sd_bus_message *m) {
 157         return
 158                 sizeof(struct bus_header) +
 159                 ALIGN8(m->fields_size) +
 160                 m->body_size;
 161 }
 162
 163 static inline size_t BUS_MESSAGE_BODY_BEGIN(sd_bus_message *m) {
 164         return
 165                 sizeof(struct bus_header) +
 166                 ALIGN8(m->fields_size);
 167 }
 168
 169 static inline void* BUS_MESSAGE_FIELDS(sd_bus_message *m) {
 170         return (uint8_t*) m->header + sizeof(struct bus_header);
 171 }
 172
 173 static inline bool BUS_MESSAGE_IS_GVARIANT(sd_bus_message *m) {
 174         return m->header->version == 2;
 175 }
 176
 177 int bus_message_get_blob(sd_bus_message *m, void **buffer, size_t *sz);
 178 int bus_message_read_strv_extend(sd_bus_message *m, char ***l);
 179
 180 int bus_message_from_header(
 181                 sd_bus *bus,
 182                 void *header,
 183                 size_t header_accessible,
 184                 void *footer,
 185                 size_t footer_accessible,
 186                 size_t message_size,
 187                 int *fds,
 188                 size_t n_fds,
 189                 const char *label,
 190                 size_t extra,
 191                 sd_bus_message **ret);
 192
 193 int bus_message_from_malloc(
 194                 sd_bus *bus,
 195                 void *buffer,
 196                 size_t length,
 197                 int *fds,
 198                 size_t n_fds,
 199                 const char *label,
 200                 sd_bus_message **ret);
 201
 202 int bus_message_get_arg(sd_bus_message *m, unsigned i, const char **str);
 203 int bus_message_get_arg_strv(sd_bus_message *m, unsigned i, char ***strv);
 204
 205 int bus_message_parse_fields(sd_bus_message *m);
 206
 207 struct bus_body_part *message_append_part(sd_bus_message *m);
 208
 209 #define MESSAGE_FOREACH_PART(part, i, m) \
 210         for ((i) = 0, (part) = &(m)->body; (i) < (m)->n_body_parts; (i)++, (part) = (part)->next)
 211
 212 int bus_body_part_map(struct bus_body_part *part);
 213 void bus_body_part_unmap(struct bus_body_part *part);
 214
 215 int bus_message_to_errno(sd_bus_message *m);
 216
 217 int bus_message_new_synthetic_error(sd_bus *bus, uint64_t serial, const sd_bus_error *e, sd_bus_message **m);
 218
 219 int bus_message_remarshal(sd_bus *bus, sd_bus_message **m);
 220
 221 void bus_message_set_sender_driver(sd_bus *bus, sd_bus_message *m);
 222 void bus_message_set_sender_local(sd_bus *bus, sd_bus_message *m);
 223
 224 sd_bus_message* bus_message_ref_queued(sd_bus_message *m, sd_bus *bus);
 225 sd_bus_message* bus_message_unref_queued(sd_bus_message *m, sd_bus *bus);