src/common/payload.h

   1 /*
   2  * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #ifndef LTTNG_PAYLOAD_H
   9 #define LTTNG_PAYLOAD_H
  10
  11 #include <common/dynamic-buffer.h>
  12 #include <common/dynamic-array.h>
  13
  14 /*
  15  * An lttng_payload encompasses the 'data' (bytes) and any passed file
  16  * descriptors as part of a message between liblttng-ctl and the session
  17  * daemon.
  18  */
  19 struct lttng_payload {
  20         struct lttng_dynamic_buffer buffer;
  21         /* private */
  22         struct lttng_dynamic_array _fds;
  23 };
  24
  25 /*
  26  * Initialize a payload. This performs no allocation and is meant
  27  * to be used instead of zero-ing the payload structure.
  28  */
  29 LTTNG_HIDDEN
  30 void lttng_payload_init(struct lttng_payload *payload);
  31
  32 /* Copy a payload. */
  33 LTTNG_HIDDEN
  34 int lttng_payload_copy(const struct lttng_payload *src_payload,
  35                 struct lttng_payload *dst_payload);
  36
  37 /* Release any memory used by the payload. */
  38 LTTNG_HIDDEN
  39 void lttng_payload_reset(struct lttng_payload *payload);
  40
  41 /**
  42  * Add an fd to the payload.
  43  * No ownership of the file descriptor is assumed by the payload.
  44  *
  45  * @payload     Payload instance
  46  * @fd          File descriptor to add to the payload
  47  *
  48  * Returns 0 on success, -1 on allocation error.
  49  */
  50 LTTNG_HIDDEN
  51 int lttng_payload_push_fd(struct lttng_payload *payload, int fd);
  52
  53 #endif /* LTTNG_PAYLOAD_H */