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