| 1 | /* |
| 2 | * Copyright (C) 2019 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> |
| 3 | * |
| 4 | * SPDX-License-Identifier: GPL-2.0-only |
| 5 | * |
| 6 | */ |
| 7 | |
| 8 | #define _LGPL_SOURCE |
| 9 | #include <inttypes.h> |
| 10 | #include <string.h> |
| 11 | #include <unistd.h> |
| 12 | |
| 13 | #include <common/defaults.h> |
| 14 | #include <common/error.h> |
| 15 | #include <common/utils.h> |
| 16 | |
| 17 | #include "clear.h" |
| 18 | #include "session.h" |
| 19 | #include "ust-app.h" |
| 20 | #include "kernel.h" |
| 21 | #include "cmd.h" |
| 22 | |
| 23 | struct cmd_clear_session_reply_context { |
| 24 | int reply_sock_fd; |
| 25 | }; |
| 26 | |
| 27 | static |
| 28 | void cmd_clear_session_reply(const struct ltt_session *session, |
| 29 | void *_reply_context) |
| 30 | { |
| 31 | int ret; |
| 32 | ssize_t comm_ret; |
| 33 | const struct cmd_clear_session_reply_context *reply_context = |
| 34 | (cmd_clear_session_reply_context *) _reply_context; |
| 35 | struct lttcomm_lttng_msg llm = { |
| 36 | .cmd_type = LTTNG_CLEAR_SESSION, |
| 37 | .ret_code = LTTNG_OK, |
| 38 | .pid = UINT32_MAX, |
| 39 | .cmd_header_size = 0, |
| 40 | .data_size = 0, |
| 41 | .fd_count = 0, |
| 42 | }; |
| 43 | |
| 44 | DBG("End of clear command: replying to client"); |
| 45 | comm_ret = lttcomm_send_unix_sock(reply_context->reply_sock_fd, |
| 46 | &llm, sizeof(llm)); |
| 47 | if (comm_ret != (ssize_t) sizeof(llm)) { |
| 48 | ERR("Failed to send result of session \"%s\" clear to client", |
| 49 | session->name); |
| 50 | } |
| 51 | ret = close(reply_context->reply_sock_fd); |
| 52 | if (ret) { |
| 53 | PERROR("Failed to close client socket in deferred session clear reply"); |
| 54 | } |
| 55 | free(_reply_context); |
| 56 | } |
| 57 | |
| 58 | int cmd_clear_session(struct ltt_session *session, int *sock_fd) |
| 59 | { |
| 60 | int ret = LTTNG_OK; |
| 61 | struct cmd_clear_session_reply_context *reply_context = NULL; |
| 62 | bool session_was_active = false; |
| 63 | struct ltt_kernel_session *ksession; |
| 64 | struct ltt_ust_session *usess; |
| 65 | |
| 66 | ksession = session->kernel_session; |
| 67 | usess = session->ust_session; |
| 68 | |
| 69 | if (sock_fd) { |
| 70 | reply_context = (cmd_clear_session_reply_context *) zmalloc(sizeof(*reply_context)); |
| 71 | if (!reply_context) { |
| 72 | ret = LTTNG_ERR_NOMEM; |
| 73 | goto end; |
| 74 | } |
| 75 | reply_context->reply_sock_fd = *sock_fd; |
| 76 | } |
| 77 | |
| 78 | if (!session->has_been_started) { |
| 79 | /* |
| 80 | * Nothing to be cleared, this is not an error: there is |
| 81 | * indeed nothing to do, and there is no reason why we |
| 82 | * should return an error to the user. |
| 83 | */ |
| 84 | goto end; |
| 85 | } |
| 86 | |
| 87 | /* Unsupported feature in lttng-relayd before 2.11. */ |
| 88 | if (session->consumer->type == CONSUMER_DST_NET && |
| 89 | (session->consumer->relay_major_version == 2 && |
| 90 | session->consumer->relay_minor_version < 12)) { |
| 91 | ret = LTTNG_ERR_CLEAR_NOT_AVAILABLE_RELAY; |
| 92 | goto end; |
| 93 | } |
| 94 | if (session->consumer->type == CONSUMER_DST_NET && |
| 95 | !session->consumer->relay_allows_clear) { |
| 96 | ret = LTTNG_ERR_CLEAR_NOT_AVAILABLE_RELAY; |
| 97 | goto end; |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * After a stop followed by a clear, all subsequent clear are |
| 102 | * effect-less until start is performed. |
| 103 | */ |
| 104 | if (session->cleared_after_last_stop) { |
| 105 | ret = LTTNG_OK; |
| 106 | goto end; |
| 107 | } |
| 108 | |
| 109 | /* |
| 110 | * After a stop followed by a rotation, all subsequent clear are effect-less |
| 111 | * until start is performed. |
| 112 | */ |
| 113 | if (session->rotated_after_last_stop) { |
| 114 | ret = LTTNG_OK; |
| 115 | goto end; |
| 116 | } |
| 117 | |
| 118 | session_was_active = session->active; |
| 119 | if (session_was_active) { |
| 120 | ret = stop_kernel_session(ksession); |
| 121 | if (ret != LTTNG_OK) { |
| 122 | goto end; |
| 123 | } |
| 124 | if (usess && usess->active) { |
| 125 | ret = ust_app_stop_trace_all(usess); |
| 126 | if (ret < 0) { |
| 127 | ret = LTTNG_ERR_UST_STOP_FAIL; |
| 128 | goto end; |
| 129 | } |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | /* |
| 134 | * Clear active kernel and UST session buffers. |
| 135 | */ |
| 136 | if (session->kernel_session) { |
| 137 | ret = kernel_clear_session(session); |
| 138 | if (ret != LTTNG_OK) { |
| 139 | goto end; |
| 140 | } |
| 141 | } |
| 142 | if (session->ust_session) { |
| 143 | ret = ust_app_clear_session(session); |
| 144 | if (ret != LTTNG_OK) { |
| 145 | goto end; |
| 146 | } |
| 147 | } |
| 148 | |
| 149 | if (session->output_traces) { |
| 150 | /* |
| 151 | * Use rotation to delete local and remote stream files. |
| 152 | */ |
| 153 | if (reply_context) { |
| 154 | ret = session_add_clear_notifier(session, |
| 155 | cmd_clear_session_reply, |
| 156 | (void *) reply_context); |
| 157 | if (ret) { |
| 158 | ret = LTTNG_ERR_FATAL; |
| 159 | goto end; |
| 160 | } |
| 161 | /* |
| 162 | * On success, ownership of reply_context has been |
| 163 | * passed to session_add_clear_notifier(). |
| 164 | */ |
| 165 | reply_context = NULL; |
| 166 | *sock_fd = -1; |
| 167 | } |
| 168 | ret = cmd_rotate_session(session, NULL, true, |
| 169 | LTTNG_TRACE_CHUNK_COMMAND_TYPE_DELETE); |
| 170 | if (ret != LTTNG_OK) { |
| 171 | goto end; |
| 172 | } |
| 173 | } |
| 174 | if (!session->active) { |
| 175 | session->cleared_after_last_stop = true; |
| 176 | } |
| 177 | if (session_was_active) { |
| 178 | /* Kernel tracing */ |
| 179 | if (ksession != NULL) { |
| 180 | DBG("Start kernel tracing session \"%s\"", |
| 181 | session->name); |
| 182 | ret = start_kernel_session(ksession); |
| 183 | if (ret != LTTNG_OK) { |
| 184 | goto end; |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | /* Flag session that trace should start automatically */ |
| 189 | if (usess) { |
| 190 | int int_ret = ust_app_start_trace_all(usess); |
| 191 | |
| 192 | if (int_ret < 0) { |
| 193 | ret = LTTNG_ERR_UST_START_FAIL; |
| 194 | goto end; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * Open a packet in every stream of the session to ensure that |
| 200 | * viewers can correctly identify the boundaries of the periods |
| 201 | * during which tracing was active for this session. |
| 202 | */ |
| 203 | ret = session_open_packets(session); |
| 204 | if (ret != LTTNG_OK) { |
| 205 | goto end; |
| 206 | } |
| 207 | } |
| 208 | ret = LTTNG_OK; |
| 209 | end: |
| 210 | free(reply_context); |
| 211 | return ret; |
| 212 | } |