| 1 | /* |
| 2 | * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation; either version 2 |
| 7 | * of the License, or (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write to the Free Software |
| 16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <errno.h> |
| 21 | #include <limits.h> |
| 22 | #include <stdio.h> |
| 23 | #include <stdlib.h> |
| 24 | #include <string.h> |
| 25 | #include <urcu/list.h> |
| 26 | #include <ust/ustctl.h> |
| 27 | |
| 28 | #include "liblttsessiondcomm.h" |
| 29 | #include "lttngerr.h" |
| 30 | #include "trace.h" |
| 31 | #include "session.h" |
| 32 | |
| 33 | static struct ltt_ust_trace *find_session_ust_trace_by_pid( |
| 34 | struct ltt_session *session, pid_t pid); |
| 35 | |
| 36 | /* |
| 37 | * find_session_ust_trace_by_pid |
| 38 | * |
| 39 | * Iterate over the session ust_traces and |
| 40 | * return a pointer or NULL if not found. |
| 41 | */ |
| 42 | static struct ltt_ust_trace *find_session_ust_trace_by_pid( |
| 43 | struct ltt_session *session, pid_t pid) |
| 44 | { |
| 45 | struct ltt_ust_trace *iter; |
| 46 | |
| 47 | cds_list_for_each_entry(iter, &session->ust_traces, list) { |
| 48 | if (iter->pid == pid) { |
| 49 | /* Found */ |
| 50 | return iter; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | return NULL; |
| 55 | } |
| 56 | |
| 57 | /* |
| 58 | * get_trace_count_per_session |
| 59 | * |
| 60 | * Return the total count of traces (ust and kernel) |
| 61 | * for the specified session. |
| 62 | */ |
| 63 | int get_trace_count_per_session(struct ltt_session *session) |
| 64 | { |
| 65 | return session->ust_trace_count + session->kern_trace_count; |
| 66 | } |
| 67 | |
| 68 | /* |
| 69 | * get_traces_per_session |
| 70 | * |
| 71 | * Fill the lttng_trace array of all the |
| 72 | * available trace of the session. |
| 73 | */ |
| 74 | void get_traces_per_session(struct ltt_session *session, struct lttng_trace *traces) |
| 75 | { |
| 76 | int i = 0; |
| 77 | struct ltt_ust_trace *ust_iter; |
| 78 | struct ltt_kernel_trace *kern_iter; |
| 79 | struct lttng_trace trace; |
| 80 | |
| 81 | DBG("Getting userspace traces for session %s", session->name); |
| 82 | |
| 83 | /* Getting userspace traces */ |
| 84 | cds_list_for_each_entry(ust_iter, &session->ust_traces, list) { |
| 85 | trace.type = USERSPACE; |
| 86 | trace.pid = ust_iter->pid; |
| 87 | strncpy(trace.name, ust_iter->name, sizeof(trace.name)); |
| 88 | trace.name[sizeof(trace.name) - 1] = '\0'; |
| 89 | memcpy(&traces[i], &trace, sizeof(trace)); |
| 90 | memset(&trace, 0, sizeof(trace)); |
| 91 | i++; |
| 92 | } |
| 93 | |
| 94 | DBG("Getting kernel traces for session %s", session->name); |
| 95 | |
| 96 | /* Getting kernel traces */ |
| 97 | cds_list_for_each_entry(kern_iter, &session->kernel_traces, list) { |
| 98 | trace.type = KERNEL; |
| 99 | strncpy(trace.name, kern_iter->name, sizeof(trace.name)); |
| 100 | trace.name[sizeof(trace.name) - 1] = '\0'; |
| 101 | memcpy(&traces[i], &trace, sizeof(trace)); |
| 102 | memset(&trace, 0, sizeof(trace)); |
| 103 | i++; |
| 104 | } |
| 105 | } |
| 106 | |
| 107 | /* |
| 108 | * ust_create_trace |
| 109 | * |
| 110 | * Create an userspace trace using pid. |
| 111 | * This trace is then appended to the current session |
| 112 | * ust trace list. |
| 113 | */ |
| 114 | int ust_create_trace(int sock, pid_t pid) |
| 115 | { |
| 116 | int ret; |
| 117 | struct ltt_ust_trace *trace; |
| 118 | |
| 119 | DBG("Creating trace for pid %d", pid); |
| 120 | |
| 121 | trace = malloc(sizeof(struct ltt_ust_trace)); |
| 122 | if (trace == NULL) { |
| 123 | perror("malloc"); |
| 124 | ret = -1; |
| 125 | goto error; |
| 126 | } |
| 127 | |
| 128 | /* Init */ |
| 129 | trace->pid = pid; |
| 130 | trace->shmid = 0; |
| 131 | /* NOTE: to be removed. Trace name will no longer be |
| 132 | * required for LTTng userspace tracer. For now, we set it |
| 133 | * to 'auto' for API compliance. |
| 134 | */ |
| 135 | snprintf(trace->name, 5, "auto"); |
| 136 | |
| 137 | ret = ustctl_create_trace(sock, trace->name); |
| 138 | if (ret < 0) { |
| 139 | ret = LTTCOMM_CREATE_FAIL; |
| 140 | goto error_create; |
| 141 | } |
| 142 | |
| 143 | /* Check if current session is valid */ |
| 144 | if (current_session) { |
| 145 | cds_list_add(&trace->list, ¤t_session->ust_traces); |
| 146 | current_session->ust_trace_count++; |
| 147 | } |
| 148 | |
| 149 | return 0; |
| 150 | |
| 151 | error_create: |
| 152 | free(trace); |
| 153 | error: |
| 154 | return ret; |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | * ust_start_trace |
| 159 | * |
| 160 | * Start a trace. This trace, identified by the pid, must be |
| 161 | * in the current session ust_traces list. |
| 162 | */ |
| 163 | int ust_start_trace(int sock, pid_t pid) |
| 164 | { |
| 165 | int ret; |
| 166 | struct ltt_ust_trace *trace; |
| 167 | |
| 168 | DBG("Starting trace for pid %d", pid); |
| 169 | |
| 170 | trace = find_session_ust_trace_by_pid(current_session, pid); |
| 171 | if (trace == NULL) { |
| 172 | ret = LTTCOMM_NO_TRACE; |
| 173 | goto error; |
| 174 | } |
| 175 | |
| 176 | ret = ustctl_start_trace(sock, "auto"); |
| 177 | if (ret < 0) { |
| 178 | ret = LTTCOMM_START_FAIL; |
| 179 | goto error; |
| 180 | } |
| 181 | |
| 182 | error: |
| 183 | return ret; |
| 184 | } |
| 185 | |
| 186 | /* |
| 187 | * ust_stop_trace |
| 188 | * |
| 189 | * Stop a trace. This trace, identified by the pid, must be |
| 190 | * in the current session ust_traces list. |
| 191 | */ |
| 192 | int ust_stop_trace(int sock, pid_t pid) |
| 193 | { |
| 194 | int ret; |
| 195 | struct ltt_ust_trace *trace; |
| 196 | |
| 197 | DBG("Stopping trace for pid %d", pid); |
| 198 | |
| 199 | trace = find_session_ust_trace_by_pid(current_session, pid); |
| 200 | if (trace == NULL) { |
| 201 | ret = LTTCOMM_NO_TRACE; |
| 202 | goto error; |
| 203 | } |
| 204 | |
| 205 | ret = ustctl_stop_trace(sock, trace->name); |
| 206 | if (ret < 0) { |
| 207 | ret = LTTCOMM_STOP_FAIL; |
| 208 | goto error; |
| 209 | } |
| 210 | |
| 211 | error: |
| 212 | return ret; |
| 213 | } |
| 214 | |