| 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 as published by |
| 6 | * the Free Software Foundation; either version 2 of the License, or |
| 7 | * (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 along |
| 15 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 16 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 17 | */ |
| 18 | |
| 19 | #define _GNU_SOURCE |
| 20 | #include <errno.h> |
| 21 | #include <fcntl.h> |
| 22 | #include <getopt.h> |
| 23 | #include <grp.h> |
| 24 | #include <limits.h> |
| 25 | #include <stdio.h> |
| 26 | #include <stdlib.h> |
| 27 | #include <string.h> |
| 28 | #include <sys/stat.h> |
| 29 | #include <sys/types.h> |
| 30 | #include <sys/wait.h> |
| 31 | #include <unistd.h> |
| 32 | |
| 33 | #include <lttng/liblttngctl.h> |
| 34 | |
| 35 | #include "lttng.h" |
| 36 | #include "lttngerr.h" |
| 37 | |
| 38 | /* Variables */ |
| 39 | static char *progname; |
| 40 | |
| 41 | /* Prototypes */ |
| 42 | static int process_client_opt(void); |
| 43 | static int process_opt_list_apps(void); |
| 44 | |
| 45 | /* |
| 46 | * start_client |
| 47 | * |
| 48 | * Process client request from the command line |
| 49 | * options. Every tracing action is done by the |
| 50 | * liblttngctl API. |
| 51 | */ |
| 52 | static int process_client_opt(void) |
| 53 | { |
| 54 | int ret; |
| 55 | |
| 56 | /* Connect to the session daemon */ |
| 57 | ret = lttng_connect_sessiond(); |
| 58 | if (ret < 0) { |
| 59 | ERR("%s", lttng_get_readable_code(ret)); |
| 60 | goto end; |
| 61 | } |
| 62 | |
| 63 | if (opt_list_apps) { |
| 64 | ret = process_opt_list_apps(); |
| 65 | if (ret < 0) { |
| 66 | ERR("%s", lttng_get_readable_code(ret)); |
| 67 | goto end; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | return 0; |
| 72 | |
| 73 | end: |
| 74 | return ret; |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * process_opt_list_apps |
| 79 | * |
| 80 | * Get the UST traceable pid list and print |
| 81 | * them to the user. |
| 82 | */ |
| 83 | static int process_opt_list_apps(void) |
| 84 | { |
| 85 | int i, ret; |
| 86 | pid_t *pids; |
| 87 | FILE *fp; |
| 88 | char path[24]; /* Can't go bigger than /proc/65535/cmdline */ |
| 89 | char cmdline[PATH_MAX]; |
| 90 | |
| 91 | ret = lttng_ust_list_apps(&pids); |
| 92 | if (ret < 0) { |
| 93 | goto error; |
| 94 | } |
| 95 | |
| 96 | MSG("LTTng UST traceable application [name (pid)]:"); |
| 97 | for (i=0; i < ret; i++) { |
| 98 | snprintf(path, sizeof(path), "/proc/%d/cmdline", pids[i]); |
| 99 | fp = fopen(path, "r"); |
| 100 | if (fp == NULL) { |
| 101 | continue; |
| 102 | } |
| 103 | ret = fread(cmdline, 1, sizeof(cmdline), fp); |
| 104 | MSG("\t%s (%d)", cmdline, pids[i]); |
| 105 | fclose(fp); |
| 106 | } |
| 107 | |
| 108 | return 0; |
| 109 | |
| 110 | error: |
| 111 | return ret; |
| 112 | } |
| 113 | |
| 114 | /* |
| 115 | * check_ltt_sessiond |
| 116 | * |
| 117 | * Check if the session daemon is available using |
| 118 | * the liblttngctl API for the check. |
| 119 | */ |
| 120 | static int check_ltt_sessiond(void) |
| 121 | { |
| 122 | int ret; |
| 123 | |
| 124 | ret = lttng_check_session_daemon(); |
| 125 | if (ret < 0) { |
| 126 | ERR("No session daemon found. Aborting."); |
| 127 | } |
| 128 | |
| 129 | return ret; |
| 130 | } |
| 131 | |
| 132 | |
| 133 | /* |
| 134 | * clean_exit |
| 135 | */ |
| 136 | void clean_exit(int code) |
| 137 | { |
| 138 | DBG("Clean exit"); |
| 139 | exit(code); |
| 140 | } |
| 141 | |
| 142 | /* |
| 143 | * main |
| 144 | */ |
| 145 | int main(int argc, char *argv[]) |
| 146 | { |
| 147 | int ret; |
| 148 | |
| 149 | progname = argv[0] ? argv[0] : "lttng"; |
| 150 | |
| 151 | /* For Mathieu Desnoyers aka Dr Tracing */ |
| 152 | if (strncmp(progname, "drtrace", 7) == 0) { |
| 153 | MSG("%c[%d;%dmWelcome back Dr Tracing!%c[%dm\n\n", 27,1,33,27,0); |
| 154 | } |
| 155 | |
| 156 | ret = parse_args(argc, (const char **) argv); |
| 157 | if (ret < 0) { |
| 158 | return EXIT_FAILURE; |
| 159 | } |
| 160 | |
| 161 | if (opt_tracing_group != NULL) { |
| 162 | DBG("Set tracing group to '%s'", opt_tracing_group); |
| 163 | lttng_set_tracing_group(opt_tracing_group); |
| 164 | } |
| 165 | |
| 166 | /* If ask for kernel tracing, need root perms */ |
| 167 | if (opt_trace_kernel) { |
| 168 | DBG("Kernel tracing activated"); |
| 169 | if (getuid() != 0) { |
| 170 | ERR("%s must be setuid root", progname); |
| 171 | return -EPERM; |
| 172 | } |
| 173 | } |
| 174 | |
| 175 | /* Check if the lttng session daemon is running. |
| 176 | * If no, a daemon will be spawned. |
| 177 | */ |
| 178 | if (check_ltt_sessiond() < 0) { |
| 179 | return EXIT_FAILURE; |
| 180 | } |
| 181 | |
| 182 | ret = process_client_opt(); |
| 183 | if (ret < 0) { |
| 184 | return ret; |
| 185 | } |
| 186 | |
| 187 | return 0; |
| 188 | } |