| 1 | /* |
| 2 | * Copyright (C) 2019 Jérémie Galarneau <jeremie.galarneau@efficios.com> |
| 3 | * Copyright (C) 2019 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 4 | * |
| 5 | * SPDX-License-Identifier: LGPL-2.1-only |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #define _LGPL_SOURCE |
| 10 | #include "lttng-ctl-helper.hpp" |
| 11 | |
| 12 | #include <common/buffer-view.hpp> |
| 13 | #include <common/compat/poll.hpp> |
| 14 | #include <common/dynamic-buffer.hpp> |
| 15 | #include <common/macros.hpp> |
| 16 | #include <common/optional.hpp> |
| 17 | #include <common/sessiond-comm/sessiond-comm.hpp> |
| 18 | |
| 19 | #include <lttng/clear-handle.h> |
| 20 | #include <lttng/clear.h> |
| 21 | #include <lttng/lttng-error.h> |
| 22 | |
| 23 | #include <algorithm> |
| 24 | #include <string.h> |
| 25 | |
| 26 | enum communication_state { |
| 27 | COMMUNICATION_STATE_RECEIVE_LTTNG_MSG, |
| 28 | COMMUNICATION_STATE_RECEIVE_COMMAND_HEADER, |
| 29 | COMMUNICATION_STATE_END, |
| 30 | COMMUNICATION_STATE_ERROR, |
| 31 | }; |
| 32 | |
| 33 | struct lttng_clear_handle { |
| 34 | LTTNG_OPTIONAL(enum lttng_error_code) clear_return_code; |
| 35 | struct { |
| 36 | int socket; |
| 37 | struct lttng_poll_event events; |
| 38 | size_t bytes_left_to_receive; |
| 39 | enum communication_state state; |
| 40 | struct lttng_dynamic_buffer buffer; |
| 41 | LTTNG_OPTIONAL(size_t) data_size; |
| 42 | } communication; |
| 43 | }; |
| 44 | |
| 45 | void lttng_clear_handle_destroy(struct lttng_clear_handle *handle) |
| 46 | { |
| 47 | int ret; |
| 48 | |
| 49 | if (!handle) { |
| 50 | return; |
| 51 | } |
| 52 | |
| 53 | if (handle->communication.socket >= 0) { |
| 54 | ret = close(handle->communication.socket); |
| 55 | if (ret) { |
| 56 | PERROR("Failed to close lttng-sessiond command socket"); |
| 57 | } |
| 58 | } |
| 59 | lttng_poll_clean(&handle->communication.events); |
| 60 | lttng_dynamic_buffer_reset(&handle->communication.buffer); |
| 61 | free(handle); |
| 62 | } |
| 63 | |
| 64 | static struct lttng_clear_handle *lttng_clear_handle_create(int sessiond_socket) |
| 65 | { |
| 66 | int ret; |
| 67 | struct lttng_clear_handle *handle = zmalloc<lttng_clear_handle>(); |
| 68 | |
| 69 | if (!handle) { |
| 70 | goto end; |
| 71 | } |
| 72 | lttng_dynamic_buffer_init(&handle->communication.buffer); |
| 73 | handle->communication.socket = sessiond_socket; |
| 74 | ret = lttng_poll_create(&handle->communication.events, 1, 0); |
| 75 | if (ret) { |
| 76 | goto error; |
| 77 | } |
| 78 | |
| 79 | ret = lttng_poll_add(&handle->communication.events, sessiond_socket, LPOLLIN | LPOLLRDHUP); |
| 80 | if (ret) { |
| 81 | goto error; |
| 82 | } |
| 83 | |
| 84 | handle->communication.bytes_left_to_receive = sizeof(struct lttcomm_lttng_msg); |
| 85 | handle->communication.state = COMMUNICATION_STATE_RECEIVE_LTTNG_MSG; |
| 86 | end: |
| 87 | return handle; |
| 88 | error: |
| 89 | lttng_clear_handle_destroy(handle); |
| 90 | return nullptr; |
| 91 | } |
| 92 | |
| 93 | static int handle_state_transition(struct lttng_clear_handle *handle) |
| 94 | { |
| 95 | int ret = 0; |
| 96 | |
| 97 | LTTNG_ASSERT(handle->communication.bytes_left_to_receive == 0); |
| 98 | |
| 99 | switch (handle->communication.state) { |
| 100 | case COMMUNICATION_STATE_RECEIVE_LTTNG_MSG: |
| 101 | { |
| 102 | const struct lttcomm_lttng_msg *msg = |
| 103 | (typeof(msg)) handle->communication.buffer.data; |
| 104 | |
| 105 | LTTNG_OPTIONAL_SET(&handle->clear_return_code, |
| 106 | (enum lttng_error_code) msg->ret_code); |
| 107 | if (handle->clear_return_code.value != LTTNG_OK) { |
| 108 | handle->communication.state = COMMUNICATION_STATE_END; |
| 109 | break; |
| 110 | } else if (msg->cmd_header_size != 0 || msg->data_size != 0) { |
| 111 | handle->communication.state = COMMUNICATION_STATE_ERROR; |
| 112 | ret = -1; |
| 113 | break; |
| 114 | } |
| 115 | |
| 116 | handle->communication.state = COMMUNICATION_STATE_END; |
| 117 | handle->communication.bytes_left_to_receive = 0; |
| 118 | LTTNG_OPTIONAL_SET(&handle->communication.data_size, 0); |
| 119 | ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0); |
| 120 | LTTNG_ASSERT(!ret); |
| 121 | break; |
| 122 | } |
| 123 | default: |
| 124 | abort(); |
| 125 | } |
| 126 | |
| 127 | /* Clear reception buffer on state transition. */ |
| 128 | if (lttng_dynamic_buffer_set_size(&handle->communication.buffer, 0)) { |
| 129 | abort(); |
| 130 | } |
| 131 | return ret; |
| 132 | } |
| 133 | |
| 134 | static int handle_incoming_data(struct lttng_clear_handle *handle) |
| 135 | { |
| 136 | int ret; |
| 137 | ssize_t comm_ret; |
| 138 | const size_t original_buffer_size = handle->communication.buffer.size; |
| 139 | |
| 140 | /* Reserve space for reception. */ |
| 141 | ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer, |
| 142 | original_buffer_size + |
| 143 | handle->communication.bytes_left_to_receive); |
| 144 | if (ret) { |
| 145 | goto end; |
| 146 | } |
| 147 | |
| 148 | comm_ret = lttcomm_recv_unix_sock(handle->communication.socket, |
| 149 | handle->communication.buffer.data + original_buffer_size, |
| 150 | handle->communication.bytes_left_to_receive); |
| 151 | if (comm_ret <= 0) { |
| 152 | ret = -1; |
| 153 | goto end; |
| 154 | } |
| 155 | |
| 156 | handle->communication.bytes_left_to_receive -= comm_ret; |
| 157 | if (handle->communication.bytes_left_to_receive == 0) { |
| 158 | ret = handle_state_transition(handle); |
| 159 | } else { |
| 160 | ret = lttng_dynamic_buffer_set_size(&handle->communication.buffer, |
| 161 | original_buffer_size + comm_ret); |
| 162 | } |
| 163 | end: |
| 164 | return ret; |
| 165 | } |
| 166 | |
| 167 | extern enum lttng_clear_handle_status |
| 168 | lttng_clear_handle_wait_for_completion(struct lttng_clear_handle *handle, int timeout_ms) |
| 169 | { |
| 170 | enum lttng_clear_handle_status status; |
| 171 | unsigned long time_left_ms = 0; |
| 172 | const bool has_timeout = timeout_ms > 0; |
| 173 | struct timespec initial_time; |
| 174 | |
| 175 | if (handle->communication.state == COMMUNICATION_STATE_ERROR) { |
| 176 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 177 | goto end; |
| 178 | } else if (handle->communication.state == COMMUNICATION_STATE_END) { |
| 179 | status = LTTNG_CLEAR_HANDLE_STATUS_COMPLETED; |
| 180 | goto end; |
| 181 | } |
| 182 | if (has_timeout) { |
| 183 | int ret = lttng_clock_gettime(CLOCK_MONOTONIC, &initial_time); |
| 184 | if (ret) { |
| 185 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 186 | goto end; |
| 187 | } |
| 188 | time_left_ms = (unsigned long) timeout_ms; |
| 189 | } |
| 190 | |
| 191 | while (handle->communication.state != COMMUNICATION_STATE_END && |
| 192 | (time_left_ms || !has_timeout)) { |
| 193 | int ret; |
| 194 | uint32_t revents; |
| 195 | struct timespec current_time, diff; |
| 196 | unsigned long diff_ms; |
| 197 | |
| 198 | ret = lttng_poll_wait(&handle->communication.events, |
| 199 | has_timeout ? time_left_ms : -1); |
| 200 | if (ret == 0) { |
| 201 | /* timeout */ |
| 202 | break; |
| 203 | } else if (ret < 0) { |
| 204 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 205 | goto end; |
| 206 | } |
| 207 | |
| 208 | /* The sessiond connection socket is the only monitored fd. */ |
| 209 | revents = LTTNG_POLL_GETEV(&handle->communication.events, 0); |
| 210 | if (revents & LPOLLIN) { |
| 211 | ret = handle_incoming_data(handle); |
| 212 | if (ret) { |
| 213 | handle->communication.state = COMMUNICATION_STATE_ERROR; |
| 214 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 215 | goto end; |
| 216 | } |
| 217 | } else { |
| 218 | handle->communication.state = COMMUNICATION_STATE_ERROR; |
| 219 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 220 | goto end; |
| 221 | } |
| 222 | if (!has_timeout) { |
| 223 | continue; |
| 224 | } |
| 225 | |
| 226 | ret = lttng_clock_gettime(CLOCK_MONOTONIC, ¤t_time); |
| 227 | if (ret) { |
| 228 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 229 | goto end; |
| 230 | } |
| 231 | diff = timespec_abs_diff(initial_time, current_time); |
| 232 | ret = timespec_to_ms(diff, &diff_ms); |
| 233 | if (ret) { |
| 234 | ERR("Failed to compute elapsed time while waiting for completion"); |
| 235 | status = LTTNG_CLEAR_HANDLE_STATUS_ERROR; |
| 236 | goto end; |
| 237 | } |
| 238 | DBG("%lums elapsed while waiting for session clear completion", diff_ms); |
| 239 | diff_ms = std::max(diff_ms, 1UL); |
| 240 | diff_ms = std::min(diff_ms, time_left_ms); |
| 241 | time_left_ms -= diff_ms; |
| 242 | } |
| 243 | |
| 244 | status = handle->communication.state == COMMUNICATION_STATE_END ? |
| 245 | LTTNG_CLEAR_HANDLE_STATUS_COMPLETED : |
| 246 | LTTNG_CLEAR_HANDLE_STATUS_TIMEOUT; |
| 247 | end: |
| 248 | return status; |
| 249 | } |
| 250 | |
| 251 | extern enum lttng_clear_handle_status |
| 252 | lttng_clear_handle_get_result(const struct lttng_clear_handle *handle, |
| 253 | enum lttng_error_code *result) |
| 254 | { |
| 255 | enum lttng_clear_handle_status status = LTTNG_CLEAR_HANDLE_STATUS_OK; |
| 256 | |
| 257 | if (!handle->clear_return_code.is_set) { |
| 258 | status = LTTNG_CLEAR_HANDLE_STATUS_INVALID; |
| 259 | goto end; |
| 260 | } |
| 261 | *result = handle->clear_return_code.value; |
| 262 | end: |
| 263 | return status; |
| 264 | } |
| 265 | |
| 266 | /* |
| 267 | * Clear the session |
| 268 | */ |
| 269 | enum lttng_error_code lttng_clear_session(const char *session_name, |
| 270 | struct lttng_clear_handle **_handle) |
| 271 | { |
| 272 | enum lttng_error_code ret_code = LTTNG_OK; |
| 273 | struct lttng_clear_handle *handle = nullptr; |
| 274 | struct lttcomm_session_msg lsm = { |
| 275 | .cmd_type = LTTCOMM_SESSIOND_COMMAND_CLEAR_SESSION, |
| 276 | .session = {}, |
| 277 | .domain = {}, |
| 278 | .u = {}, |
| 279 | .fd_count = 0, |
| 280 | }; |
| 281 | int sessiond_socket = -1; |
| 282 | ssize_t comm_ret; |
| 283 | int ret; |
| 284 | |
| 285 | if (session_name == nullptr) { |
| 286 | ret_code = LTTNG_ERR_INVALID; |
| 287 | goto error; |
| 288 | } |
| 289 | ret = lttng_strncpy(lsm.session.name, session_name, sizeof(lsm.session.name)); |
| 290 | if (ret) { |
| 291 | ret_code = LTTNG_ERR_INVALID; |
| 292 | goto error; |
| 293 | } |
| 294 | ret = connect_sessiond(); |
| 295 | if (ret < 0) { |
| 296 | ret_code = LTTNG_ERR_NO_SESSIOND; |
| 297 | goto error; |
| 298 | } else { |
| 299 | sessiond_socket = ret; |
| 300 | } |
| 301 | handle = lttng_clear_handle_create(sessiond_socket); |
| 302 | if (!handle) { |
| 303 | ret_code = LTTNG_ERR_NOMEM; |
| 304 | goto error; |
| 305 | } |
| 306 | comm_ret = lttcomm_send_creds_unix_sock(sessiond_socket, &lsm, sizeof(lsm)); |
| 307 | if (comm_ret < 0) { |
| 308 | ret_code = LTTNG_ERR_FATAL; |
| 309 | goto error; |
| 310 | } |
| 311 | sessiond_socket = -1; |
| 312 | |
| 313 | error: |
| 314 | /* Transfer the handle to the caller. */ |
| 315 | if (_handle) { |
| 316 | *_handle = handle; |
| 317 | handle = nullptr; |
| 318 | } |
| 319 | if (sessiond_socket >= 0) { |
| 320 | ret = close(sessiond_socket); |
| 321 | if (ret < 0) { |
| 322 | PERROR("Failed to close the LTTng session daemon connection socket"); |
| 323 | } |
| 324 | } |
| 325 | if (handle) { |
| 326 | lttng_clear_handle_destroy(handle); |
| 327 | } |
| 328 | return ret_code; |
| 329 | } |