src/common/payload-view.c

   1 /*
   2  * Copyright (C) 2020 Jérémie Galarneau <jeremie.galarneau@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <common/dynamic-array.h>
   9 #include <common/buffer-view.h>
  10 #include "payload-view.h"
  11 #include "payload.h"
  12 #include <stddef.h>
  13
  14 LTTNG_HIDDEN
  15 struct lttng_payload_view lttng_payload_view_from_payload(
  16                 const struct lttng_payload *payload, size_t offset,
  17                 ptrdiff_t len)
  18 {
  19         return (struct lttng_payload_view) {
  20                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  21                         &payload->buffer, offset, len),
  22                 ._fds = payload->_fds,
  23         };
  24 }
  25
  26 LTTNG_HIDDEN
  27 struct lttng_payload_view lttng_payload_view_from_view(
  28                 struct lttng_payload_view *view, size_t offset,
  29                 ptrdiff_t len)
  30 {
  31         return (struct lttng_payload_view) {
  32                 .buffer = lttng_buffer_view_from_view(
  33                         &view->buffer, offset, len),
  34                 ._fds = view->_fds,
  35                 ._iterator.p_fds_position = &view->_iterator.fds_position,
  36         };
  37 }
  38
  39 LTTNG_HIDDEN
  40 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  41                 const struct lttng_dynamic_buffer *buffer, size_t offset,
  42                 ptrdiff_t len)
  43 {
  44         return (struct lttng_payload_view) {
  45                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  46                         buffer, offset, len)
  47         };
  48 }
  49
  50 LTTNG_HIDDEN
  51 struct lttng_payload_view lttng_payload_view_from_buffer_view(
  52                 const struct lttng_buffer_view *view, size_t offset,
  53                 ptrdiff_t len)
  54 {
  55         return (struct lttng_payload_view) {
  56                 .buffer = lttng_buffer_view_from_view(
  57                         view, offset, len)
  58         };
  59 }
  60
  61 LTTNG_HIDDEN
  62 int lttng_payload_view_get_fd_count(struct lttng_payload_view *payload_view)
  63 {
  64         int ret;
  65         size_t position;
  66
  67         if (!payload_view) {
  68                 ret = -1;
  69                 goto end;
  70         }
  71
  72         ret = lttng_dynamic_array_get_count(&payload_view->_fds);
  73         if (ret < 0) {
  74                 goto end;
  75         }
  76
  77         position = payload_view->_iterator.p_fds_position ?
  78                         *payload_view->_iterator.p_fds_position :
  79                         payload_view->_iterator.fds_position;
  80         ret = ret - (int) position;
  81 end:
  82         return ret;
  83 }
  84
  85 LTTNG_HIDDEN
  86 int lttng_payload_view_pop_fd(struct lttng_payload_view *view)
  87 {
  88         int ret = 0;
  89         size_t fd_count;
  90         size_t *pos;
  91
  92         if (!view) {
  93                 ret = -1;
  94                 goto end;
  95         }
  96
  97         fd_count = lttng_dynamic_array_get_count(&view->_fds);
  98         pos = view->_iterator.p_fds_position ? view->_iterator.p_fds_position :
  99                 &view->_iterator.fds_position;
 100
 101         if (*pos >= fd_count) {
 102                 ret = -1;
 103                 goto end;
 104         }
 105
 106         ret = *((int *) lttng_dynamic_array_get_element(
 107                         &view->_fds, *pos));
 108         (*pos)++;
 109 end:
 110         return ret;
 111 }