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 modify
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <popt.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <sys/stat.h>
  24 #include <sys/types.h>
  25 #include <unistd.h>
  26 #include <inttypes.h>
  27
  28 #include "../command.h"
  29
  30 #include <src/common/sessiond-comm/sessiond-comm.h>
  31
  32 static char *opt_channels;
  33 static int opt_kernel;
  34 static char *opt_session_name;
  35 static int opt_userspace;
  36 static struct lttng_channel chan;
  37 #if 0
  38 /* Not implemented yet */
  39 static char *opt_cmd_name;
  40 static pid_t opt_pid;
  41 #endif
  42
  43 enum {
  44         OPT_HELP = 1,
  45         OPT_DISCARD,
  46         OPT_OVERWRITE,
  47         OPT_SUBBUF_SIZE,
  48         OPT_NUM_SUBBUF,
  49         OPT_SWITCH_TIMER,
  50         OPT_READ_TIMER,
  51         OPT_USERSPACE,
  52         OPT_LIST_OPTIONS,
  53 };
  54
  55 static struct lttng_handle *handle;
  56
  57 static struct poptOption long_options[] = {
  58         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  59         {"help",           'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
  60         {"session",        's', POPT_ARG_STRING, &opt_session_name, 0, 0, 0},
  61         {"kernel",         'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
  62 #if 0
  63         /* Not implemented yet */
  64         {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
  65         {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
  66 #else
  67         {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
  68 #endif
  69         {"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
  70         {"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
  71         {"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
  72         {"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
  73         {"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
  74         {"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
  75         {"list-options",   0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
  76         {0, 0, 0, 0, 0, 0, 0}
  77 };
  78
  79 /*
  80  * usage
  81  */
  82 static void usage(FILE *ofp)
  83 {
  84         fprintf(ofp, "usage: lttng enable-channel NAME[,NAME2,...] [options] [channel_options]\n");
  85         fprintf(ofp, "\n");
  86         fprintf(ofp, "  -h, --help               Show this help\n");
  87         fprintf(ofp, "      --list-options       Simple listing of options\n");
  88         fprintf(ofp, "  -s, --session            Apply to session name\n");
  89         fprintf(ofp, "  -k, --kernel             Apply to the kernel tracer\n");
  90 #if 0
  91         fprintf(ofp, "  -u, --userspace [CMD]    Apply to the user-space tracer\n");
  92         fprintf(ofp, "                           If no CMD, the domain used is UST global\n");
  93         fprintf(ofp, "                           or else the domain is UST EXEC_NAME\n");
  94         fprintf(ofp, "  -p, --pid PID            If -u, apply to specific PID (domain: UST PID)\n");
  95 #else
  96         fprintf(ofp, "  -u, --userspace          Apply to the user-space tracer\n");
  97 #endif
  98         fprintf(ofp, "\n");
  99         fprintf(ofp, "Channel options:\n");
 100         fprintf(ofp, "      --discard            Discard event when buffers are full%s\n",
 101                 DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
 102         fprintf(ofp, "      --overwrite          Flight recorder mode%s\n",
 103                 DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
 104         fprintf(ofp, "      --subbuf-size SIZE   Subbuffer size in bytes\n");
 105         fprintf(ofp, "                               (default: %u, kernel default: %u)\n",
 106                 DEFAULT_CHANNEL_SUBBUF_SIZE,
 107                 DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
 108         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 109         fprintf(ofp, "                               kernel and ust tracers\n");
 110         fprintf(ofp, "      --num-subbuf NUM     Number of subbufers\n");
 111         fprintf(ofp, "                               (default: %u)\n",
 112                 DEFAULT_CHANNEL_SUBBUF_NUM);
 113         fprintf(ofp, "                               Needs to be a power of 2 for\n");
 114         fprintf(ofp, "                               kernel and ust tracers\n");
 115         fprintf(ofp, "      --switch-timer USEC  Switch timer interval in usec (default: %u)\n",
 116                 DEFAULT_CHANNEL_SWITCH_TIMER);
 117         fprintf(ofp, "      --read-timer USEC    Read timer interval in usec (default: %u)\n",
 118                 DEFAULT_CHANNEL_READ_TIMER);
 119         fprintf(ofp, "\n");
 120 }
 121
 122 /*
 123  * Set default attributes depending on those already defined from the command
 124  * line.
 125  */
 126 static void set_default_attr(struct lttng_domain *dom)
 127 {
 128         struct lttng_channel_attr default_attr;
 129
 130         /* Set attributes */
 131         lttng_channel_set_default_attr(dom, &default_attr);
 132
 133         if (chan.attr.overwrite == -1) {
 134                 chan.attr.overwrite = default_attr.overwrite;
 135         }
 136         if (chan.attr.subbuf_size == -1) {
 137                 chan.attr.subbuf_size = default_attr.subbuf_size;
 138         }
 139         if (chan.attr.num_subbuf == -1) {
 140                 chan.attr.num_subbuf = default_attr.num_subbuf;
 141         }
 142         if (chan.attr.switch_timer_interval == -1) {
 143                 chan.attr.switch_timer_interval = default_attr.switch_timer_interval;
 144         }
 145         if (chan.attr.read_timer_interval == -1) {
 146                 chan.attr.read_timer_interval = default_attr.read_timer_interval;
 147         }
 148         if (chan.attr.output == -1) {
 149                 chan.attr.output = default_attr.output;
 150         }
 151 }
 152
 153 /*
 154  * Adding channel using the lttng API.
 155  */
 156 static int enable_channel(char *session_name)
 157 {
 158         int ret = CMD_SUCCESS, warn = 0;
 159         char *channel_name;
 160         struct lttng_domain dom;
 161
 162         memset(&dom, 0, sizeof(dom));
 163
 164         /* Create lttng domain */
 165         if (opt_kernel) {
 166                 dom.type = LTTNG_DOMAIN_KERNEL;
 167         } else if (opt_userspace) {
 168                 dom.type = LTTNG_DOMAIN_UST;
 169         } else {
 170                 ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
 171                 ret = CMD_ERROR;
 172                 goto error;
 173         }
 174
 175         set_default_attr(&dom);
 176
 177         handle = lttng_create_handle(session_name, &dom);
 178         if (handle == NULL) {
 179                 ret = -1;
 180                 goto error;
 181         }
 182
 183         /* Strip channel list (format: chan1,chan2,...) */
 184         channel_name = strtok(opt_channels, ",");
 185         while (channel_name != NULL) {
 186                 /* Copy channel name and normalize it */
 187                 strncpy(chan.name, channel_name, NAME_MAX);
 188                 chan.name[NAME_MAX - 1] = '\0';
 189
 190                 DBG("Enabling channel %s", channel_name);
 191
 192                 ret = lttng_enable_channel(handle, &chan);
 193                 if (ret < 0) {
 194                         switch (-ret) {
 195                         case LTTCOMM_KERN_CHAN_EXIST:
 196                         case LTTCOMM_UST_CHAN_EXIST:
 197                                 WARN("Channel %s: %s (session %s", channel_name,
 198                                                 lttng_strerror(ret), session_name);
 199                                 goto error;
 200                         default:
 201                                 ERR("Channel %s: %s (session %s)", channel_name,
 202                                                 lttng_strerror(ret), session_name);
 203                                 break;
 204                         }
 205                         warn = 1;
 206                 } else {
 207                         MSG("%s channel %s enabled for session %s",
 208                                         opt_kernel ? "Kernel" : "UST", channel_name,
 209                                         session_name);
 210                 }
 211
 212                 /* Next event */
 213                 channel_name = strtok(NULL, ",");
 214         }
 215
 216         ret = CMD_SUCCESS;
 217
 218 error:
 219         if (warn) {
 220                 ret = CMD_WARNING;
 221         }
 222
 223         lttng_destroy_handle(handle);
 224
 225         return ret;
 226 }
 227
 228 /*
 229  * Default value for channel configuration.
 230  */
 231 static void init_channel_config(void)
 232 {
 233         /*
 234          * Put -1 everywhere so we can identify those set by the command line and
 235          * those needed to be set by the default values.
 236          */
 237         memset(&chan.attr, -1, sizeof(chan.attr));
 238 }
 239
 240 /*
 241  * Add channel to trace session
 242  */
 243 int cmd_enable_channels(int argc, const char **argv)
 244 {
 245         int opt, ret = CMD_SUCCESS;
 246         static poptContext pc;
 247         char *session_name = NULL;
 248
 249         init_channel_config();
 250
 251         pc = poptGetContext(NULL, argc, argv, long_options, 0);
 252         poptReadDefaultConfig(pc, 0);
 253
 254         while ((opt = poptGetNextOpt(pc)) != -1) {
 255                 switch (opt) {
 256                 case OPT_HELP:
 257                         usage(stdout);
 258                         goto end;
 259                 case OPT_DISCARD:
 260                         chan.attr.overwrite = 0;
 261                         DBG("Channel set to discard");
 262                         break;
 263                 case OPT_OVERWRITE:
 264                         chan.attr.overwrite = 1;
 265                         DBG("Channel set to overwrite");
 266                         break;
 267                 case OPT_SUBBUF_SIZE:
 268                         /* TODO Replace atol with strtol and check for errors */
 269                         chan.attr.subbuf_size = atol(poptGetOptArg(pc));
 270                         DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
 271                         break;
 272                 case OPT_NUM_SUBBUF:
 273                         /* TODO Replace atoi with strtol and check for errors */
 274                         chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
 275                         DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
 276                         break;
 277                 case OPT_SWITCH_TIMER:
 278                         /* TODO Replace atoi with strtol and check for errors */
 279                         chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
 280                         DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
 281                         break;
 282                 case OPT_READ_TIMER:
 283                         /* TODO Replace atoi with strtol and check for errors */
 284                         chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
 285                         DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
 286                         break;
 287                 case OPT_USERSPACE:
 288                         opt_userspace = 1;
 289                         break;
 290                 case OPT_LIST_OPTIONS:
 291                         list_cmd_options(stdout, long_options);
 292                         goto end;
 293                 default:
 294                         usage(stderr);
 295                         ret = CMD_UNDEFINED;
 296                         goto end;
 297                 }
 298         }
 299
 300         opt_channels = (char*) poptGetArg(pc);
 301         if (opt_channels == NULL) {
 302                 ERR("Missing channel name.\n");
 303                 usage(stderr);
 304                 ret = CMD_ERROR;
 305                 goto end;
 306         }
 307
 308         if (!opt_session_name) {
 309                 session_name = get_session_name();
 310                 if (session_name == NULL) {
 311                         ret = CMD_ERROR;
 312                         goto end;
 313                 }
 314         } else {
 315                 session_name = opt_session_name;
 316         }
 317
 318         ret = enable_channel(session_name);
 319
 320 end:
 321         if (!opt_session_name && session_name) {
 322                 free(session_name);
 323         }
 324         poptFreeContext(pc);
 325         return ret;
 326 }