1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22 23 /* 24 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 25 * Use is subject to license terms. 26 */ 27 28 #pragma ident "%Z%%M% %I% %E% SMI" 29 30 #include <sys/sysevent/eventdefs.h> 31 #include <sys/sysevent.h> 32 #include <sys/sysevent_impl.h> 33 #include <sys/fm/protocol.h> 34 #include <sys/sysmacros.h> 35 #include <sys/dumphdr.h> 36 #include <sys/dumpadm.h> 37 #include <sys/fm/util.h> 38 39 #include <libsysevent.h> 40 #include <libnvpair.h> 41 #include <alloca.h> 42 #include <limits.h> 43 #include <strings.h> 44 #include <unistd.h> 45 #include <fcntl.h> 46 #include <errno.h> 47 48 #undef MUTEX_HELD 49 #undef RW_READ_HELD 50 #undef RW_WRITE_HELD 51 52 #include <fmd_api.h> 53 #include <fmd_log.h> 54 #include <fmd_subr.h> 55 #include <fmd_dispq.h> 56 #include <fmd_module.h> 57 #include <fmd_scheme.h> 58 #include <fmd_error.h> 59 60 #include <fmd.h> 61 62 static char *sysev_channel; /* event channel to which we are subscribed */ 63 static char *sysev_class; /* event class to which we are subscribed */ 64 static char *sysev_device; /* device path to use for replaying events */ 65 static char *sysev_sid; /* event channel subscriber identifier */ 66 static void *sysev_evc; /* event channel cookie from evc_bind */ 67 68 static fmd_xprt_t *sysev_xprt; 69 static fmd_hdl_t *sysev_hdl; 70 71 static struct sysev_stats { 72 fmd_stat_t dump_replay; 73 fmd_stat_t dump_lost; 74 fmd_stat_t bad_class; 75 fmd_stat_t bad_attr; 76 fmd_stat_t eagain; 77 } sysev_stats = { 78 { "dump_replay", FMD_TYPE_UINT64, "events replayed from dump device" }, 79 { "dump_lost", FMD_TYPE_UINT64, "events lost from dump device" }, 80 { "bad_class", FMD_TYPE_UINT64, "events dropped due to invalid class" }, 81 { "bad_attr", FMD_TYPE_UINT64, "events dropped due to invalid nvlist" }, 82 { "eagain", FMD_TYPE_UINT64, "events retried due to low memory" }, 83 }; 84 85 /* 86 * Receive an event from the SysEvent channel and post it to our transport. 87 * Under extreme low-memory situations where we cannot event unpack the event, 88 * we can request that SysEvent redeliver the event later by returning EAGAIN. 89 * If we do this too many times, the kernel will drop the event. Rather than 90 * keeping state per-event, we simply attempt a garbage-collect, hoping that 91 * enough free memory will be available by the time the event is redelivered. 92 */ 93 static int 94 sysev_recv(sysevent_t *sep, void *arg) 95 { 96 uint64_t seq = sysevent_get_seq(sep); 97 fmd_xprt_t *xp = arg; 98 nvlist_t *nvl; 99 hrtime_t hrt; 100 101 if (strcmp(sysevent_get_class_name(sep), EC_FM) != 0) { 102 fmd_hdl_error(sysev_hdl, "discarding event 0x%llx: unexpected" 103 " transport class %s\n", seq, sysevent_get_class_name(sep)); 104 sysev_stats.bad_class.fmds_value.ui64++; 105 return (0); 106 } 107 108 if (sysevent_get_attr_list(sep, &nvl) != 0) { 109 if (errno == EAGAIN || errno == ENOMEM) { 110 fmd_modhash_tryapply(fmd.d_mod_hash, fmd_module_trygc); 111 fmd_scheme_hash_trygc(fmd.d_schemes); 112 sysev_stats.eagain.fmds_value.ui64++; 113 return (EAGAIN); 114 } 115 116 fmd_hdl_error(sysev_hdl, "discarding event 0x%llx: missing " 117 "or invalid payload", seq); 118 sysev_stats.bad_attr.fmds_value.ui64++; 119 return (0); 120 } 121 122 sysevent_get_time(sep, &hrt); 123 fmd_xprt_post(sysev_hdl, xp, nvl, hrt); 124 return (0); 125 } 126 127 /* 128 * Checksum algorithm used by the dump transport for verifying the content of 129 * error reports saved on the dump device (copy of the kernel's checksum32()). 130 */ 131 static uint32_t 132 sysev_checksum(void *cp_arg, size_t length) 133 { 134 uchar_t *cp, *ep; 135 uint32_t sum = 0; 136 137 for (cp = cp_arg, ep = cp + length; cp < ep; cp++) 138 sum = ((sum >> 1) | (sum << 31)) + *cp; 139 140 return (sum); 141 } 142 143 /* 144 * Replay saved events from the dump transport. This function is installed as 145 * the timer callback and is called only once during the module's lifetime. 146 */ 147 /*ARGSUSED*/ 148 static void 149 sysev_replay(fmd_hdl_t *hdl, id_t id, void *arg) 150 { 151 char *dumpdev; 152 off64_t off, off0; 153 int fd, err; 154 155 /* 156 * Determine the appropriate dump device to use for replaying pending 157 * error reports. If the device property is NULL (default), we 158 * open and query /dev/dump to determine the current dump device. 159 */ 160 if ((dumpdev = sysev_device) == NULL) { 161 if ((fd = open("/dev/dump", O_RDONLY)) == -1) { 162 fmd_hdl_error(hdl, "failed to open /dev/dump " 163 "to locate dump device for event replay"); 164 return; 165 } 166 167 dumpdev = alloca(PATH_MAX); 168 err = ioctl(fd, DIOCGETDEV, dumpdev); 169 (void) close(fd); 170 171 if (err == -1) { 172 if (errno != ENODEV) { 173 fmd_hdl_error(hdl, "failed to obtain " 174 "path to dump device for event replay"); 175 } 176 return; 177 } 178 } 179 180 if (strcmp(dumpdev, "/dev/null") == 0) 181 return; /* return silently and skip replay for /dev/null */ 182 183 /* 184 * Open the appropriate device and then determine the offset of the 185 * start of the ereport dump region located at the end of the device. 186 */ 187 if ((fd = open64(dumpdev, O_RDWR | O_DSYNC)) == -1) { 188 fmd_hdl_error(hdl, "failed to open dump transport %s " 189 "(pending events will not be replayed)", dumpdev); 190 return; 191 } 192 193 off = DUMP_OFFSET + DUMP_LOGSIZE + DUMP_ERPTSIZE; 194 off = off0 = lseek64(fd, -off, SEEK_END) & -DUMP_OFFSET; 195 196 if (off == (off64_t)-1LL) { 197 fmd_hdl_error(hdl, "failed to seek dump transport %s " 198 "(pending events will not be replayed)", dumpdev); 199 (void) close(fd); 200 return; 201 } 202 203 /* 204 * The ereport dump region is a sequence of erpt_dump_t headers each of 205 * which is followed by packed nvlist data. We iterate over them in 206 * order, unpacking and dispatching each one to our dispatch queue. 207 */ 208 for (;;) { 209 char nvbuf[ERPT_DATA_SZ]; 210 uint32_t chksum; 211 erpt_dump_t ed; 212 nvlist_t *nvl; 213 214 fmd_timeval_t ftv, tod; 215 hrtime_t hrt; 216 uint64_t ena; 217 218 if (pread64(fd, &ed, sizeof (ed), off) != sizeof (ed)) { 219 fmd_hdl_error(hdl, "failed to read from dump " 220 "transport %s (pending events lost)", dumpdev); 221 break; 222 } 223 224 if (ed.ed_magic == 0 && ed.ed_size == 0) 225 break; /* end of list: all zero */ 226 227 if (ed.ed_magic == 0) { 228 off += sizeof (ed) + ed.ed_size; 229 continue; /* continue searching */ 230 } 231 232 if (ed.ed_magic != ERPT_MAGIC) { 233 /* 234 * Stop reading silently if the first record has the 235 * wrong magic number; this likely indicates that we 236 * rebooted from non-FMA bits or paged over the dump. 237 */ 238 if (off == off0) 239 break; 240 241 fmd_hdl_error(hdl, "invalid dump transport " 242 "record at %llx (magic number %x, expected %x)\n", 243 (u_longlong_t)off, ed.ed_magic, ERPT_MAGIC); 244 break; 245 } 246 247 if (ed.ed_size > ERPT_DATA_SZ) { 248 fmd_hdl_error(hdl, "invalid dump transport " 249 "record at %llx size (%u exceeds limit)\n", 250 (u_longlong_t)off, ed.ed_size); 251 break; 252 } 253 254 if (pread64(fd, nvbuf, ed.ed_size, 255 off + sizeof (ed)) != ed.ed_size) { 256 fmd_hdl_error(hdl, "failed to read dump " 257 "transport event (offset %llx)", (u_longlong_t)off); 258 259 sysev_stats.dump_lost.fmds_value.ui64++; 260 goto next; 261 } 262 263 if ((chksum = sysev_checksum(nvbuf, 264 ed.ed_size)) != ed.ed_chksum) { 265 fmd_hdl_error(hdl, "dump transport event at " 266 "offset %llx is corrupt (checksum %x != %x)\n", 267 (u_longlong_t)off, chksum, ed.ed_chksum); 268 269 sysev_stats.dump_lost.fmds_value.ui64++; 270 goto next; 271 } 272 273 if ((err = nvlist_xunpack(nvbuf, 274 ed.ed_size, &nvl, &fmd.d_nva)) != 0) { 275 fmd_hdl_error(hdl, "failed to unpack dump " 276 "transport event at offset %llx: %s\n", 277 (u_longlong_t)off, fmd_strerror(err)); 278 279 sysev_stats.dump_lost.fmds_value.ui64++; 280 goto next; 281 } 282 283 /* 284 * If ed_hrt_nsec is set it contains the gethrtime() value from 285 * when the event was originally enqueued for the transport. 286 * If it is zero, we use the weaker bound ed_hrt_base instead. 287 */ 288 if (ed.ed_hrt_nsec != 0) 289 hrt = ed.ed_hrt_nsec; 290 else 291 hrt = ed.ed_hrt_base; 292 293 /* 294 * If this is an FMA protocol event of class "ereport.*" that 295 * contains valid ENA, we can improve the precision of 'hrt'. 296 */ 297 if (nvlist_lookup_uint64(nvl, FM_EREPORT_ENA, &ena) == 0) 298 hrt = fmd_time_ena2hrt(hrt, ena); 299 300 /* 301 * Now convert 'hrt' to an adjustable TOD based on the values 302 * in ed_tod_base which correspond to one another and are 303 * sampled before reboot using the old gethrtime() clock. 304 * fmd_event_recreate() will use this TOD value to re-assign 305 * the event an updated gethrtime() value based on the current 306 * value of the non-adjustable gethrtime() clock. Phew. 307 */ 308 tod.ftv_sec = ed.ed_tod_base.sec; 309 tod.ftv_nsec = ed.ed_tod_base.nsec; 310 fmd_time_hrt2tod(ed.ed_hrt_base, &tod, hrt, &ftv); 311 312 (void) nvlist_remove_all(nvl, FMD_EVN_TOD); 313 (void) nvlist_add_uint64_array(nvl, 314 FMD_EVN_TOD, (uint64_t *)&ftv, 2); 315 316 fmd_xprt_post(hdl, sysev_xprt, nvl, 0); 317 sysev_stats.dump_replay.fmds_value.ui64++; 318 319 next: 320 /* 321 * Reset the magic number for the event record to zero so that 322 * we do not replay the same event multiple times. 323 */ 324 ed.ed_magic = 0; 325 326 if (pwrite64(fd, &ed, sizeof (ed), off) != sizeof (ed)) { 327 fmd_hdl_error(hdl, "failed to mark dump " 328 "transport event (offset %llx)", (u_longlong_t)off); 329 } 330 331 off += sizeof (ed) + ed.ed_size; 332 } 333 334 (void) close(fd); 335 } 336 337 static const fmd_prop_t sysev_props[] = { 338 { "class", FMD_TYPE_STRING, EC_ALL }, /* event class */ 339 { "device", FMD_TYPE_STRING, NULL }, /* replay device */ 340 { "channel", FMD_TYPE_STRING, FM_ERROR_CHAN }, /* channel name */ 341 { "sid", FMD_TYPE_STRING, "fmd" }, /* subscriber id */ 342 { NULL, 0, NULL } 343 }; 344 345 static const fmd_hdl_ops_t sysev_ops = { 346 NULL, /* fmdo_recv */ 347 sysev_replay, /* fmdo_timeout */ 348 NULL, /* fmdo_close */ 349 NULL, /* fmdo_stats */ 350 NULL, /* fmdo_gc */ 351 NULL, /* fmdo_send */ 352 }; 353 354 static const fmd_hdl_info_t sysev_info = { 355 "SysEvent Transport Agent", "1.0", &sysev_ops, sysev_props 356 }; 357 358 /* 359 * Bind to the sysevent channel we use for listening for error events and then 360 * subscribe to appropriate events received over this channel. 361 */ 362 void 363 sysev_init(fmd_hdl_t *hdl) 364 { 365 uint_t flags; 366 367 if (fmd_hdl_register(hdl, FMD_API_VERSION, &sysev_info) != 0) 368 return; /* invalid property settings */ 369 370 (void) fmd_stat_create(hdl, FMD_STAT_NOALLOC, sizeof (sysev_stats) / 371 sizeof (fmd_stat_t), (fmd_stat_t *)&sysev_stats); 372 373 sysev_channel = fmd_prop_get_string(hdl, "channel"); 374 sysev_class = fmd_prop_get_string(hdl, "class"); 375 sysev_device = fmd_prop_get_string(hdl, "device"); 376 sysev_sid = fmd_prop_get_string(hdl, "sid"); 377 378 if (sysev_channel == NULL) 379 fmd_hdl_abort(hdl, "channel property must be defined\n"); 380 381 if (sysev_sid == NULL) 382 fmd_hdl_abort(hdl, "sid property must be defined\n"); 383 384 if ((errno = sysevent_evc_bind(sysev_channel, &sysev_evc, 385 EVCH_CREAT | EVCH_HOLD_PEND)) != 0) { 386 fmd_hdl_abort(hdl, "failed to bind to event transport " 387 "channel %s", sysev_channel); 388 } 389 390 sysev_xprt = fmd_xprt_open(hdl, FMD_XPRT_RDONLY, NULL, NULL); 391 sysev_hdl = hdl; 392 393 /* 394 * If we're subscribing to the default channel, keep our subscription 395 * active even if we die unexpectedly so we continue queuing events. 396 * If we're not (e.g. running under fmsim), do not specify SUB_KEEP so 397 * that our event channel will be destroyed if we die unpleasantly. 398 */ 399 if (strcmp(sysev_channel, FM_ERROR_CHAN) == 0) 400 flags = EVCH_SUB_KEEP | EVCH_SUB_DUMP; 401 else 402 flags = EVCH_SUB_DUMP; 403 404 errno = sysevent_evc_subscribe(sysev_evc, 405 sysev_sid, sysev_class, sysev_recv, sysev_xprt, flags); 406 407 if (errno != 0) { 408 if (errno == EEXIST) { 409 fmd_hdl_abort(hdl, "another fault management daemon is " 410 "active on transport channel %s\n", sysev_channel); 411 } else { 412 fmd_hdl_abort(hdl, "failed to subscribe to %s on " 413 "transport channel %s", sysev_class, sysev_channel); 414 } 415 } 416 417 /* 418 * Once the transport is open, install a single timer to fire at once 419 * in the context of the module's thread to run sysev_replay(). This 420 * thread will block in its first fmd_xprt_post() until fmd is ready. 421 */ 422 fmd_hdl_debug(hdl, "transport '%s' open\n", sysev_channel); 423 (void) fmd_timer_install(hdl, NULL, NULL, 0); 424 } 425 426 /* 427 * Close the channel by unsubscribing and unbinding. We only do this when a 428 * a non-default channel has been selected. If we're using FM_ERROR_CHAN, 429 * the system default, we do *not* want to unsubscribe because the kernel will 430 * remove the subscriber queue and any events published in our absence will 431 * therefore be lost. This scenario may occur when, for example, fmd is sent 432 * a SIGTERM by init(1M) during reboot but an error is detected and makes it 433 * into the sysevent channel queue before init(1M) manages to call uadmin(2). 434 */ 435 void 436 sysev_fini(fmd_hdl_t *hdl) 437 { 438 if (strcmp(sysev_channel, FM_ERROR_CHAN) != 0) { 439 sysevent_evc_unsubscribe(sysev_evc, sysev_sid); 440 sysevent_evc_unbind(sysev_evc); 441 } 442 443 if (sysev_xprt != NULL) 444 fmd_xprt_close(hdl, sysev_xprt); 445 446 fmd_prop_free_string(hdl, sysev_class); 447 fmd_prop_free_string(hdl, sysev_channel); 448 fmd_prop_free_string(hdl, sysev_device); 449 fmd_prop_free_string(hdl, sysev_sid); 450 } 451