src/common/snapshot.cpp

   1 /*
   2  * Copyright (C) 2020 Simon Marchi <simon.marchi@efficios.com>
   3  *
   4  * SPDX-License-Identifier: LGPL-2.1-only
   5  *
   6  */
   7
   8 #include <common/error.hpp>
   9 #include <common/mi-lttng.hpp>
  10 #include <common/payload-view.hpp>
  11 #include <common/payload.hpp>
  12 #include <common/snapshot.hpp>
  13 #include <lttng/snapshot-internal.hpp>
  14 #include <lttng/snapshot.h>
  15
  16 #include <stdlib.h>
  17
  18 bool lttng_snapshot_output_validate(const struct lttng_snapshot_output *output)
  19 {
  20         bool valid = false;
  21         size_t len;
  22
  23         /*
  24          * It is mandatory to have a ctrl_url. If there is only one output
  25          * URL (in the net://, net6:// or file:// form), it will be in this
  26          * field.
  27          */
  28         len = lttng_strnlen(output->ctrl_url, sizeof(output->ctrl_url));
  29         if (len == 0 || len >= sizeof(output->ctrl_url)) {
  30                 goto end;
  31         }
  32
  33         len = lttng_strnlen(output->data_url, sizeof(output->data_url));
  34         if (len >= sizeof(output->data_url)) {
  35                 goto end;
  36         }
  37
  38         len = lttng_strnlen(output->name, sizeof(output->name));
  39         if (len >= sizeof(output->name)) {
  40                 goto end;
  41         }
  42
  43         valid = true;
  44
  45 end:
  46         return valid;
  47 }
  48
  49 bool lttng_snapshot_output_is_equal(
  50                 const struct lttng_snapshot_output *a,
  51                 const struct lttng_snapshot_output *b)
  52 {
  53         bool equal = false;
  54
  55         LTTNG_ASSERT(a);
  56         LTTNG_ASSERT(b);
  57
  58         if (a->max_size != b->max_size) {
  59                 goto end;
  60         }
  61
  62         if (strcmp(a->name, b->name) != 0) {
  63                 goto end;
  64         }
  65
  66         if (strcmp(a->ctrl_url, b->ctrl_url) != 0) {
  67                 goto end;
  68         }
  69
  70         if (strcmp(a->data_url, b->data_url) != 0) {
  71                 goto end;
  72         }
  73
  74         equal = true;
  75
  76 end:
  77         return equal;
  78 }
  79
  80 /*
  81  * This is essentially the same as `struct lttng_snapshot_output`, but packed.
  82  */
  83 struct lttng_snapshot_output_comm {
  84         uint32_t id;
  85         uint64_t max_size;
  86         char name[LTTNG_NAME_MAX];
  87         char ctrl_url[PATH_MAX];
  88         char data_url[PATH_MAX];
  89 } LTTNG_PACKED;
  90
  91 int lttng_snapshot_output_serialize(
  92                 const struct lttng_snapshot_output *output,
  93                 struct lttng_payload *payload)
  94 {
  95         struct lttng_snapshot_output_comm comm;
  96         int ret;
  97
  98         comm.id = output->id;
  99         comm.max_size = output->max_size;
 100
 101         ret = lttng_strncpy(comm.name, output->name, sizeof(comm.name));
 102         if (ret) {
 103                 goto end;
 104         }
 105
 106         ret = lttng_strncpy(
 107                         comm.ctrl_url, output->ctrl_url, sizeof(comm.ctrl_url));
 108         if (ret) {
 109                 goto end;
 110         }
 111
 112         ret = lttng_strncpy(
 113                         comm.data_url, output->data_url, sizeof(comm.data_url));
 114         if (ret) {
 115                 goto end;
 116         }
 117
 118         ret = lttng_dynamic_buffer_append(
 119                         &payload->buffer, &comm, sizeof(comm));
 120         if (ret) {
 121                 goto end;
 122         }
 123
 124 end:
 125         return ret;
 126 }
 127
 128 ssize_t lttng_snapshot_output_create_from_payload(
 129                 struct lttng_payload_view *view,
 130                 struct lttng_snapshot_output **output_p)
 131 {
 132         const struct lttng_snapshot_output_comm *comm;
 133         struct lttng_snapshot_output *output = NULL;
 134         int ret;
 135
 136         if (view->buffer.size != sizeof(*comm)) {
 137                 ret = -1;
 138                 goto end;
 139         }
 140
 141         output = lttng_snapshot_output_create();
 142         if (!output) {
 143                 ret = -1;
 144                 goto end;
 145         }
 146
 147         comm = (typeof(comm)) view->buffer.data;
 148
 149         output->id = comm->id;
 150         output->max_size = comm->max_size;
 151
 152         ret = lttng_strncpy(output->name, comm->name, sizeof(output->name));
 153         if (ret) {
 154                 goto end;
 155         }
 156
 157         ret = lttng_strncpy(output->ctrl_url, comm->ctrl_url,
 158                         sizeof(output->ctrl_url));
 159         if (ret) {
 160                 goto end;
 161         }
 162
 163         ret = lttng_strncpy(output->data_url, comm->data_url,
 164                         sizeof(output->data_url));
 165         if (ret) {
 166                 goto end;
 167         }
 168
 169         *output_p = output;
 170         output = NULL;
 171         ret = sizeof(*comm);
 172
 173 end:
 174         lttng_snapshot_output_destroy(output);
 175         return ret;
 176 }
 177
 178 enum lttng_error_code lttng_snapshot_output_mi_serialize(
 179                 const struct lttng_snapshot_output *output,
 180                 struct mi_writer *writer)
 181 {
 182         int ret;
 183         enum lttng_error_code ret_code;
 184
 185         LTTNG_ASSERT(output);
 186         LTTNG_ASSERT(writer);
 187
 188         /* Open output element. */
 189         ret = mi_lttng_writer_open_element(writer,
 190                         mi_lttng_element_action_snapshot_session_output);
 191         if (ret) {
 192                 goto mi_error;
 193         }
 194
 195         /* Name. */
 196         if (strnlen(output->name, LTTNG_NAME_MAX) != 0) {
 197                 ret = mi_lttng_writer_write_element_string(
 198                                 writer, config_element_name, output->name);
 199                 if (ret) {
 200                         goto mi_error;
 201                 }
 202         }
 203
 204         /* Control url (always present). */
 205         ret = mi_lttng_writer_write_element_string(writer,
 206                         mi_lttng_element_snapshot_ctrl_url, output->ctrl_url);
 207         if (ret) {
 208                 goto mi_error;
 209         }
 210
 211         /* Data url (optional). */
 212         if (strnlen(output->data_url, PATH_MAX) != 0) {
 213                 ret = mi_lttng_writer_write_element_string(writer,
 214                                 mi_lttng_element_snapshot_data_url,
 215                                 output->data_url);
 216                 if (ret) {
 217                         goto mi_error;
 218                 }
 219         }
 220
 221         /*
 222          * Maximum size in bytes of the snapshot meaning the total size of all
 223          * streams combined. A value of 0 means unlimited. The default value is
 224          * UINT64_MAX which also means unlimited in practice.
 225          *
 226          * The value is not serialized when it is set to either of those values
 227          * to normalize them to '0'.
 228          */
 229         if (output->max_size > 0 && output->max_size != UINT64_MAX) {
 230                 /* Total size of all stream combined. */
 231                 ret = mi_lttng_writer_write_element_unsigned_int(writer,
 232                                 mi_lttng_element_snapshot_max_size,
 233                                 output->max_size);
 234                 if (ret) {
 235                         goto mi_error;
 236                 }
 237         }
 238
 239         /* Close output element. */
 240         ret = mi_lttng_writer_close_element(writer);
 241         if (ret) {
 242                 goto mi_error;
 243         }
 244
 245         ret_code = LTTNG_OK;
 246         goto end;
 247
 248 mi_error:
 249         ret_code = LTTNG_ERR_MI_IO_FAIL;
 250 end:
 251         return ret_code;
 252 }