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