| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License, version 2 only, |
| 6 | * as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | * |
| 13 | * You should have received a copy of the GNU General Public License along |
| 14 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 16 | */ |
| 17 | |
| 18 | #define _GNU_SOURCE |
| 19 | #include <inttypes.h> |
| 20 | #include <string.h> |
| 21 | #include <unistd.h> |
| 22 | |
| 23 | #include <common/common.h> |
| 24 | #include <common/defaults.h> |
| 25 | #include <common/sessiond-comm/sessiond-comm.h> |
| 26 | |
| 27 | #include "channel.h" |
| 28 | #include "lttng-sessiond.h" |
| 29 | #include "kernel.h" |
| 30 | #include "ust-ctl.h" |
| 31 | #include "utils.h" |
| 32 | #include "ust-app.h" |
| 33 | |
| 34 | /* |
| 35 | * Return allocated channel attributes. |
| 36 | */ |
| 37 | struct lttng_channel *channel_new_default_attr(int dom, |
| 38 | enum lttng_buffer_type type) |
| 39 | { |
| 40 | struct lttng_channel *chan; |
| 41 | |
| 42 | chan = zmalloc(sizeof(struct lttng_channel)); |
| 43 | if (chan == NULL) { |
| 44 | PERROR("zmalloc channel init"); |
| 45 | goto error_alloc; |
| 46 | } |
| 47 | |
| 48 | if (snprintf(chan->name, sizeof(chan->name), "%s", |
| 49 | DEFAULT_CHANNEL_NAME) < 0) { |
| 50 | PERROR("snprintf default channel name"); |
| 51 | goto error; |
| 52 | } |
| 53 | |
| 54 | /* Same for all domains. */ |
| 55 | chan->attr.overwrite = DEFAULT_CHANNEL_OVERWRITE; |
| 56 | chan->attr.tracefile_size = DEFAULT_CHANNEL_TRACEFILE_SIZE; |
| 57 | chan->attr.tracefile_count = DEFAULT_CHANNEL_TRACEFILE_COUNT; |
| 58 | |
| 59 | switch (dom) { |
| 60 | case LTTNG_DOMAIN_KERNEL: |
| 61 | assert(type == LTTNG_BUFFER_GLOBAL); |
| 62 | chan->attr.subbuf_size = |
| 63 | default_get_kernel_channel_subbuf_size(); |
| 64 | chan->attr.num_subbuf = DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM; |
| 65 | chan->attr.output = DEFAULT_KERNEL_CHANNEL_OUTPUT; |
| 66 | chan->attr.switch_timer_interval = DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER; |
| 67 | chan->attr.read_timer_interval = DEFAULT_KERNEL_CHANNEL_READ_TIMER; |
| 68 | break; |
| 69 | case LTTNG_DOMAIN_UST: |
| 70 | switch (type) { |
| 71 | case LTTNG_BUFFER_PER_UID: |
| 72 | chan->attr.subbuf_size = default_get_ust_uid_channel_subbuf_size(); |
| 73 | chan->attr.num_subbuf = DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM; |
| 74 | chan->attr.output = DEFAULT_UST_UID_CHANNEL_OUTPUT; |
| 75 | chan->attr.switch_timer_interval = |
| 76 | DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER; |
| 77 | chan->attr.read_timer_interval = |
| 78 | DEFAULT_UST_UID_CHANNEL_READ_TIMER; |
| 79 | break; |
| 80 | case LTTNG_BUFFER_PER_PID: |
| 81 | default: |
| 82 | chan->attr.subbuf_size = default_get_ust_pid_channel_subbuf_size(); |
| 83 | chan->attr.num_subbuf = DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM; |
| 84 | chan->attr.output = DEFAULT_UST_PID_CHANNEL_OUTPUT; |
| 85 | chan->attr.switch_timer_interval = |
| 86 | DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER; |
| 87 | chan->attr.read_timer_interval = |
| 88 | DEFAULT_UST_PID_CHANNEL_READ_TIMER; |
| 89 | break; |
| 90 | } |
| 91 | break; |
| 92 | default: |
| 93 | goto error; /* Not implemented */ |
| 94 | } |
| 95 | |
| 96 | return chan; |
| 97 | |
| 98 | error: |
| 99 | free(chan); |
| 100 | error_alloc: |
| 101 | return NULL; |
| 102 | } |
| 103 | |
| 104 | /* |
| 105 | * Disable kernel channel of the kernel session. |
| 106 | */ |
| 107 | int channel_kernel_disable(struct ltt_kernel_session *ksession, |
| 108 | char *channel_name) |
| 109 | { |
| 110 | int ret; |
| 111 | struct ltt_kernel_channel *kchan; |
| 112 | |
| 113 | assert(ksession); |
| 114 | assert(channel_name); |
| 115 | |
| 116 | kchan = trace_kernel_get_channel_by_name(channel_name, ksession); |
| 117 | if (kchan == NULL) { |
| 118 | ret = LTTNG_ERR_KERN_CHAN_NOT_FOUND; |
| 119 | goto error; |
| 120 | } |
| 121 | |
| 122 | /* Only if channel is enabled disable it. */ |
| 123 | if (kchan->enabled == 1) { |
| 124 | ret = kernel_disable_channel(kchan); |
| 125 | if (ret < 0 && ret != -EEXIST) { |
| 126 | ret = LTTNG_ERR_KERN_CHAN_DISABLE_FAIL; |
| 127 | goto error; |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | ret = LTTNG_OK; |
| 132 | |
| 133 | error: |
| 134 | return ret; |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * Enable kernel channel of the kernel session. |
| 139 | */ |
| 140 | int channel_kernel_enable(struct ltt_kernel_session *ksession, |
| 141 | struct ltt_kernel_channel *kchan) |
| 142 | { |
| 143 | int ret; |
| 144 | |
| 145 | assert(ksession); |
| 146 | assert(kchan); |
| 147 | |
| 148 | if (kchan->enabled == 0) { |
| 149 | ret = kernel_enable_channel(kchan); |
| 150 | if (ret < 0) { |
| 151 | ret = LTTNG_ERR_KERN_CHAN_ENABLE_FAIL; |
| 152 | goto error; |
| 153 | } |
| 154 | } else { |
| 155 | ret = LTTNG_ERR_KERN_CHAN_EXIST; |
| 156 | goto error; |
| 157 | } |
| 158 | |
| 159 | ret = LTTNG_OK; |
| 160 | |
| 161 | error: |
| 162 | return ret; |
| 163 | } |
| 164 | |
| 165 | /* |
| 166 | * Create kernel channel of the kernel session and notify kernel thread. |
| 167 | */ |
| 168 | int channel_kernel_create(struct ltt_kernel_session *ksession, |
| 169 | struct lttng_channel *attr, int kernel_pipe) |
| 170 | { |
| 171 | int ret; |
| 172 | struct lttng_channel *defattr = NULL; |
| 173 | |
| 174 | assert(ksession); |
| 175 | |
| 176 | /* Creating channel attributes if needed */ |
| 177 | if (attr == NULL) { |
| 178 | defattr = channel_new_default_attr(LTTNG_DOMAIN_KERNEL, |
| 179 | LTTNG_BUFFER_GLOBAL); |
| 180 | if (defattr == NULL) { |
| 181 | ret = LTTNG_ERR_FATAL; |
| 182 | goto error; |
| 183 | } |
| 184 | attr = defattr; |
| 185 | } |
| 186 | |
| 187 | if (ksession->snapshot_mode) { |
| 188 | /* Force channel attribute for snapshot mode. */ |
| 189 | attr->attr.overwrite = 1; |
| 190 | attr->attr.output = LTTNG_EVENT_MMAP; |
| 191 | } |
| 192 | |
| 193 | /* Channel not found, creating it */ |
| 194 | ret = kernel_create_channel(ksession, attr); |
| 195 | if (ret < 0) { |
| 196 | ret = LTTNG_ERR_KERN_CHAN_FAIL; |
| 197 | goto error; |
| 198 | } |
| 199 | |
| 200 | /* Notify kernel thread that there is a new channel */ |
| 201 | ret = notify_thread_pipe(kernel_pipe); |
| 202 | if (ret < 0) { |
| 203 | ret = LTTNG_ERR_FATAL; |
| 204 | goto error; |
| 205 | } |
| 206 | |
| 207 | ret = LTTNG_OK; |
| 208 | error: |
| 209 | free(defattr); |
| 210 | return ret; |
| 211 | } |
| 212 | |
| 213 | /* |
| 214 | * Enable UST channel for session and domain. |
| 215 | */ |
| 216 | int channel_ust_enable(struct ltt_ust_session *usess, |
| 217 | struct ltt_ust_channel *uchan) |
| 218 | { |
| 219 | int ret = LTTNG_OK; |
| 220 | |
| 221 | assert(usess); |
| 222 | assert(uchan); |
| 223 | |
| 224 | /* If already enabled, everything is OK */ |
| 225 | if (uchan->enabled) { |
| 226 | DBG3("Channel %s already enabled. Skipping", uchan->name); |
| 227 | ret = LTTNG_ERR_UST_CHAN_EXIST; |
| 228 | goto end; |
| 229 | } |
| 230 | |
| 231 | DBG2("Channel %s being enabled in UST domain", uchan->name); |
| 232 | |
| 233 | /* |
| 234 | * Enable channel for UST global domain on all applications. Ignore return |
| 235 | * value here since whatever error we got, it means that the channel was |
| 236 | * not created on one or many registered applications and we can not report |
| 237 | * this to the user yet. However, at this stage, the channel was |
| 238 | * successfully created on the session daemon side so the enable-channel |
| 239 | * command is a success. |
| 240 | */ |
| 241 | (void) ust_app_enable_channel_glb(usess, uchan); |
| 242 | |
| 243 | uchan->enabled = 1; |
| 244 | DBG2("Channel %s enabled successfully", uchan->name); |
| 245 | |
| 246 | end: |
| 247 | return ret; |
| 248 | } |
| 249 | |
| 250 | /* |
| 251 | * Create UST channel for session and domain. |
| 252 | */ |
| 253 | int channel_ust_create(struct ltt_ust_session *usess, |
| 254 | struct lttng_channel *attr, enum lttng_buffer_type type) |
| 255 | { |
| 256 | int ret = LTTNG_OK; |
| 257 | struct ltt_ust_channel *uchan = NULL; |
| 258 | struct lttng_channel *defattr = NULL; |
| 259 | |
| 260 | assert(usess); |
| 261 | |
| 262 | /* Creating channel attributes if needed */ |
| 263 | if (attr == NULL) { |
| 264 | defattr = channel_new_default_attr(LTTNG_DOMAIN_UST, type); |
| 265 | if (defattr == NULL) { |
| 266 | ret = LTTNG_ERR_FATAL; |
| 267 | goto error; |
| 268 | } |
| 269 | attr = defattr; |
| 270 | } |
| 271 | |
| 272 | if (usess->snapshot_mode) { |
| 273 | /* Force channel attribute for snapshot mode. */ |
| 274 | attr->attr.overwrite = 1; |
| 275 | attr->attr.output = LTTNG_EVENT_MMAP; |
| 276 | } |
| 277 | |
| 278 | /* |
| 279 | * Validate UST buffer size and number of buffers: must both be power of 2 |
| 280 | * and nonzero. We validate right here for UST, because applications will |
| 281 | * not report the error to the user (unlike kernel tracing). |
| 282 | */ |
| 283 | if (!attr->attr.subbuf_size || |
| 284 | (attr->attr.subbuf_size & (attr->attr.subbuf_size - 1))) { |
| 285 | ret = LTTNG_ERR_INVALID; |
| 286 | goto error; |
| 287 | } |
| 288 | |
| 289 | /* |
| 290 | * Invalid subbuffer size if it's lower then the page size. |
| 291 | */ |
| 292 | if (attr->attr.subbuf_size < page_size) { |
| 293 | ret = LTTNG_ERR_INVALID; |
| 294 | goto error; |
| 295 | } |
| 296 | |
| 297 | if (!attr->attr.num_subbuf || |
| 298 | (attr->attr.num_subbuf & (attr->attr.num_subbuf - 1))) { |
| 299 | ret = LTTNG_ERR_INVALID; |
| 300 | goto error; |
| 301 | } |
| 302 | |
| 303 | if (attr->attr.output != LTTNG_EVENT_MMAP) { |
| 304 | ret = LTTNG_ERR_NOT_SUPPORTED; |
| 305 | goto error; |
| 306 | } |
| 307 | |
| 308 | /* |
| 309 | * The tracefile_size should not be < to the subbuf_size, otherwise |
| 310 | * we won't be able to write the packets on disk |
| 311 | */ |
| 312 | if ((attr->attr.tracefile_size > 0) && |
| 313 | (attr->attr.tracefile_size < attr->attr.subbuf_size)) { |
| 314 | ret = LTTNG_ERR_INVALID; |
| 315 | goto error; |
| 316 | } |
| 317 | |
| 318 | /* Validate buffer type. */ |
| 319 | switch (type) { |
| 320 | case LTTNG_BUFFER_PER_PID: |
| 321 | break; |
| 322 | case LTTNG_BUFFER_PER_UID: |
| 323 | break; |
| 324 | default: |
| 325 | ret = LTTNG_ERR_BUFFER_NOT_SUPPORTED; |
| 326 | goto error; |
| 327 | } |
| 328 | |
| 329 | /* Create UST channel */ |
| 330 | uchan = trace_ust_create_channel(attr); |
| 331 | if (uchan == NULL) { |
| 332 | ret = LTTNG_ERR_FATAL; |
| 333 | goto error; |
| 334 | } |
| 335 | uchan->enabled = 1; |
| 336 | if (trace_ust_is_max_id(usess->used_channel_id)) { |
| 337 | ret = LTTNG_ERR_UST_CHAN_FAIL; |
| 338 | goto error; |
| 339 | } |
| 340 | uchan->id = trace_ust_get_next_chan_id(usess); |
| 341 | |
| 342 | DBG2("Channel %s is being created for UST with buffer %d and id %" PRIu64, |
| 343 | uchan->name, type, uchan->id); |
| 344 | |
| 345 | /* Flag session buffer type. */ |
| 346 | if (!usess->buffer_type_changed) { |
| 347 | usess->buffer_type = type; |
| 348 | usess->buffer_type_changed = 1; |
| 349 | } else if (usess->buffer_type != type) { |
| 350 | /* Buffer type was already set. Refuse to create channel. */ |
| 351 | ret = LTTNG_ERR_BUFFER_TYPE_MISMATCH; |
| 352 | goto error_free_chan; |
| 353 | } |
| 354 | |
| 355 | /* Enable channel for global domain */ |
| 356 | ret = ust_app_create_channel_glb(usess, uchan); |
| 357 | if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { |
| 358 | ret = LTTNG_ERR_UST_CHAN_FAIL; |
| 359 | goto error_free_chan; |
| 360 | } |
| 361 | |
| 362 | /* Adding the channel to the channel hash table. */ |
| 363 | rcu_read_lock(); |
| 364 | lttng_ht_add_unique_str(usess->domain_global.channels, &uchan->node); |
| 365 | rcu_read_unlock(); |
| 366 | |
| 367 | DBG2("Channel %s created successfully", uchan->name); |
| 368 | |
| 369 | free(defattr); |
| 370 | return LTTNG_OK; |
| 371 | |
| 372 | error_free_chan: |
| 373 | /* |
| 374 | * No need to remove the channel from the hash table because at this point |
| 375 | * it was not added hence the direct call and no call_rcu(). |
| 376 | */ |
| 377 | trace_ust_destroy_channel(uchan); |
| 378 | error: |
| 379 | free(defattr); |
| 380 | return ret; |
| 381 | } |
| 382 | |
| 383 | /* |
| 384 | * Disable UST channel for session and domain. |
| 385 | */ |
| 386 | int channel_ust_disable(struct ltt_ust_session *usess, |
| 387 | struct ltt_ust_channel *uchan) |
| 388 | { |
| 389 | int ret = LTTNG_OK; |
| 390 | |
| 391 | assert(usess); |
| 392 | assert(uchan); |
| 393 | |
| 394 | /* Already disabled */ |
| 395 | if (uchan->enabled == 0) { |
| 396 | DBG2("Channel UST %s already disabled", uchan->name); |
| 397 | goto end; |
| 398 | } |
| 399 | |
| 400 | DBG2("Channel %s being disabled in UST global domain", uchan->name); |
| 401 | /* Disable channel for global domain */ |
| 402 | ret = ust_app_disable_channel_glb(usess, uchan); |
| 403 | if (ret < 0 && ret != -LTTNG_UST_ERR_EXIST) { |
| 404 | ret = LTTNG_ERR_UST_CHAN_DISABLE_FAIL; |
| 405 | goto error; |
| 406 | } |
| 407 | |
| 408 | uchan->enabled = 0; |
| 409 | |
| 410 | DBG2("Channel %s disabled successfully", uchan->name); |
| 411 | |
| 412 | return LTTNG_OK; |
| 413 | |
| 414 | end: |
| 415 | error: |
| 416 | return ret; |
| 417 | } |