src/bin/lttng/commands/enable_channels.c

   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; only version 2
   7  * of the License.
   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 <popt.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <sys/stat.h>
  25 #include <sys/types.h>
  26 #include <unistd.h>
  27 #include <inttypes.h>
  28
  29 #include "../command.h"
  30
  31 static char *opt_channels;
  32 static int opt_kernel;
  33 static char *opt_session_name;
  34 static int opt_userspace;
  35 static struct lttng_channel chan;
  36 #if 0
  37 /* Not implemented yet */
  38 static char *opt_cmd_name;
  39 static pid_t opt_pid;
  40 #endif
  41
  42 enum {
  43         OPT_HELP = 1,
  44         OPT_DISCARD,
  45         OPT_OVERWRITE,
  46         OPT_SUBBUF_SIZE,
  47         OPT_NUM_SUBBUF,
  48         OPT_SWITCH_TIMER,
  49         OPT_READ_TIMER,
  50         OPT_USERSPACE,
  51         OPT_LIST_OPTIONS,
  52 };
  53
  54 static struct lttng_handle *handle;
  55
  56 static struct poptOption long_options[] = {
  57         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  58         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  59         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  60         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  61 #if 0
  62         /* Not implemented yet */
  63         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  64         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  65 #else
  66         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  67 #endif
  68         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  69         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  70         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  71         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  72         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  73         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  74         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  75         {0, 0, 0, 0, 0, 0, 0}
  76 };
  77
  78 /*
  79  * usage
  80  */
  81 static void usage(FILE *ofp)
  82 {
  83         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  84         fprintf(ofp, "\n");
  85         fprintf(ofp, "  -h, --help               Show this help\n");
  86         fprintf(ofp, "      --list-options       Simple listing of options\n");
  87         fprintf(ofp, "  -s, --session            Apply on session name\n");
  88         fprintf(ofp, "  -k, --kernel             Apply on the kernel tracer\n");
  89 #if 0
  90         fprintf(ofp, "  -u, --userspace [CMD]    Apply for the user-space tracer\n");
  91         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
  92         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
  93         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
  94 #else
  95         fprintf(ofp, "  -u, --userspace          Apply for the user-space tracer\n");
  96 #endif
  97         fprintf(ofp, "\n");
  98         fprintf(ofp, "Channel options:\n");
  99         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
 100                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
 101         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
 102                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
 103         fprintf(ofp, "      --subbuf-size        Subbuffer size in bytes\n");
 104         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
 105                 DEFAULT_CHANNEL_SUBBUF_SIZE,
 106                 DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
 107         fprintf(ofp, "      --num-subbuf         Number of subbufers\n");
 108         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
 109                 DEFAULT_CHANNEL_SUBBUF_NUM,
 110                 DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM);
 111         fprintf(ofp, "      --switch-timer       Switch timer interval in usec (default: %u)\n",
 112                 DEFAULT_CHANNEL_SWITCH_TIMER);
 113         fprintf(ofp, "      --read-timer         Read timer interval in usec (default: %u)\n",
 114                 DEFAULT_CHANNEL_READ_TIMER);
 115         fprintf(ofp, "\n");
 116 }
 117
 118 /*
 119  * Set default attributes depending on those already defined from the command
 120  * line.
 121  */
 122 static void set_default_attr(struct lttng_domain *dom)
 123 {
 124         struct lttng_channel_attr default_attr;
 125
 126         /* Set attributes */
 127         lttng_channel_set_default_attr(dom, &default_attr);
 128
 129         if (chan.attr.overwrite == -1) {
 130                 chan.attr.overwrite = default_attr.overwrite;
 131         }
 132         if (chan.attr.subbuf_size == -1) {
 133                 chan.attr.subbuf_size = default_attr.subbuf_size;
 134         }
 135         if (chan.attr.num_subbuf == -1) {
 136                 chan.attr.num_subbuf = default_attr.num_subbuf;
 137         }
 138         if (chan.attr.switch_timer_interval == -1) {
 139                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 140         }
 141         if (chan.attr.read_timer_interval == -1) {
 142                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 143         }
 144         if (chan.attr.output == -1) {
 145                 chan.attr.output = default_attr.output;
 146         }
 147 }
 148
 149 /*
 150  * Adding channel using the lttng API.
 151  */
 152 static int enable_channel(char *session_name)
 153 {
 154         int ret = CMD_SUCCESS;
 155         char *channel_name;
 156         struct lttng_domain dom;
 157
 158         /* Create lttng domain */
 159         if (opt_kernel) {
 160                 dom.type = LTTNG_DOMAIN_KERNEL;
 161         } else if (opt_userspace) {
 162                 dom.type = LTTNG_DOMAIN_UST;
 163         } else {
 164                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 165                 ret = CMD_ERROR;
 166                 goto error;
 167         }
 168
 169         set_default_attr(&dom);
 170
 171         handle = lttng_create_handle(session_name, &dom);
 172         if (handle == NULL) {
 173                 ret = -1;
 174                 goto error;
 175         }
 176
 177         /* Strip channel list (format: chan1,chan2,...) */
 178         channel_name = strtok(opt_channels, ",");
 179         while (channel_name != NULL) {
 180                 /* Copy channel name and normalize it */
 181                 strncpy(chan.name, channel_name, NAME_MAX);
 182                 chan.name[NAME_MAX - 1] = '\0';
 183
 184                 DBG("Enabling channel %s", channel_name);
 185
 186                 ret = lttng_enable_channel(handle, &chan);
 187                 if (ret < 0) {
 188                         goto error;
 189                 } else {
 190                         MSG("%s channel %s enabled for session %s",
 191                                         opt_kernel ? "Kernel" : "UST", channel_name,
 192                                         session_name);
 193                 }
 194
 195                 /* Next event */
 196                 channel_name = strtok(NULL, ",");
 197         }
 198
 199 error:
 200         lttng_destroy_handle(handle);
 201
 202         return ret;
 203 }
 204
 205 /*
 206  * Default value for channel configuration.
 207  */
 208 static void init_channel_config(void)
 209 {
 210         /*
 211          * Put -1 everywhere so we can identify those set by the command line and
 212          * those needed to be set by the default values.
 213          */
 214         memset(&chan.attr, -1, sizeof(chan.attr));
 215 }
 216
 217 /*
 218  * Add channel to trace session
 219  */
 220 int cmd_enable_channels(int argc, const char **argv)
 221 {
 222         int opt, ret;
 223         static poptContext pc;
 224         char *session_name = NULL;
 225
 226         init_channel_config();
 227
 228         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 229         poptReadDefaultConfig(pc, 0);
 230
 231         while ((opt = poptGetNextOpt(pc)) != -1) {
 232                 switch (opt) {
 233                 case OPT_HELP:
 234                         usage(stderr);
 235                         ret = CMD_SUCCESS;
 236                         goto end;
 237                 case OPT_DISCARD:
 238                         chan.attr.overwrite = 0;
 239                         DBG("Channel set to discard");
 240                         break;
 241                 case OPT_OVERWRITE:
 242                         chan.attr.overwrite = 1;
 243                         DBG("Channel set to overwrite");
 244                         break;
 245                 case OPT_SUBBUF_SIZE:
 246                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 247                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 248                         break;
 249                 case OPT_NUM_SUBBUF:
 250                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 251                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 252                         break;
 253                 case OPT_SWITCH_TIMER:
 254                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 255                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 256                         break;
 257                 case OPT_READ_TIMER:
 258                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 259                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 260                         break;
 261                 case OPT_USERSPACE:
 262                         opt_userspace = 1;
 263                         break;
 264                 case OPT_LIST_OPTIONS:
 265                         list_cmd_options(stdout, long_options);
 266                         ret = CMD_SUCCESS;
 267                         goto end;
 268                 default:
 269                         usage(stderr);
 270                         ret = CMD_UNDEFINED;
 271                         goto end;
 272                 }
 273         }
 274
 275         opt_channels = (char*) poptGetArg(pc);
 276         if (opt_channels == NULL) {
 277                 ERR("Missing channel name.\n");
 278                 usage(stderr);
 279                 ret = CMD_SUCCESS;
 280                 goto end;
 281         }
 282
 283         if (!opt_session_name) {
 284                 session_name = get_session_name();
 285                 if (session_name == NULL) {
 286                         ret = -1;
 287                         goto end;
 288                 }
 289         } else {
 290                 session_name = opt_session_name;
 291         }
 292
 293         ret = enable_channel(session_name);
 294
 295 end:
 296         return ret;
 297 }