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.p_fds_position ?:
  36                                 &view->_iterator.fds_position,
  37         };
  38 }
  39
  40 LTTNG_HIDDEN
  41 struct lttng_payload_view lttng_payload_view_from_dynamic_buffer(
  42                 const struct lttng_dynamic_buffer *buffer, size_t offset,
  43                 ptrdiff_t len)
  44 {
  45         return (struct lttng_payload_view) {
  46                 .buffer = lttng_buffer_view_from_dynamic_buffer(
  47                         buffer, offset, len)
  48         };
  49 }
  50
  51 LTTNG_HIDDEN
  52 struct lttng_payload_view lttng_payload_view_from_buffer_view(
  53                 const struct lttng_buffer_view *view, size_t offset,
  54                 ptrdiff_t len)
  55 {
  56         return (struct lttng_payload_view) {
  57                 .buffer = lttng_buffer_view_from_view(
  58                         view, offset, len)
  59         };
  60 }
  61
  62 LTTNG_HIDDEN
  63 int lttng_payload_view_get_fd_count(struct lttng_payload_view *payload_view)
  64 {
  65         int ret;
  66         size_t position;
  67
  68         if (!payload_view) {
  69                 ret = -1;
  70                 goto end;
  71         }
  72
  73         ret = lttng_dynamic_array_get_count(&payload_view->_fds);
  74         if (ret < 0) {
  75                 goto end;
  76         }
  77
  78         position = payload_view->_iterator.p_fds_position ?
  79                         *payload_view->_iterator.p_fds_position :
  80                         payload_view->_iterator.fds_position;
  81         ret = ret - (int) position;
  82 end:
  83         return ret;
  84 }
  85
  86 LTTNG_HIDDEN
  87 int lttng_payload_view_pop_fd(struct lttng_payload_view *view)
  88 {
  89         int ret = 0;
  90         size_t fd_count;
  91         size_t *pos;
  92
  93         if (!view) {
  94                 ret = -1;
  95                 goto end;
  96         }
  97
  98         fd_count = lttng_dynamic_array_get_count(&view->_fds);
  99         pos = view->_iterator.p_fds_position ? view->_iterator.p_fds_position :
 100                 &view->_iterator.fds_position;
 101
 102         if (*pos >= fd_count) {
 103                 ret = -1;
 104                 goto end;
 105         }
 106
 107         ret = *((int *) lttng_dynamic_array_get_element(
 108                         &view->_fds, *pos));
 109         (*pos)++;
 110 end:
 111         return ret;
 112 }