lib/zlog.c

   1 /*
   2  * Copyright (c) 2015-19  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #include "zebra.h"
  18
  19 #include <unistd.h>
  20 #include <sys/time.h>
  21 #include <sys/mman.h>
  22 #include <sys/types.h>
  23 #include <time.h>
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdarg.h>
  28 #include <pthread.h>
  29
  30 /* gettid() & co. */
  31 #ifdef HAVE_PTHREAD_NP_H
  32 #include <pthread_np.h>
  33 #endif
  34 #ifdef linux
  35 #include <sys/syscall.h>
  36 #endif
  37 #ifdef __FreeBSD__
  38 #include <sys/thr.h>
  39 #endif
  40 #ifdef __NetBSD__
  41 #include <lwp.h>
  42 #endif
  43 #ifdef __DragonFly__
  44 #include <sys/lwp.h>
  45 #endif
  46 #ifdef __APPLE__
  47 #include <mach/mach_traps.h>
  48 #endif
  49
  50 #include "memory.h"
  51 #include "atomlist.h"
  52 #include "printfrr.h"
  53 #include "frrcu.h"
  54 #include "zlog.h"
  55 #include "libfrr_trace.h"
  56
  57 DEFINE_MTYPE_STATIC(LIB, LOG_MESSAGE,  "log message");
  58 DEFINE_MTYPE_STATIC(LIB, LOG_TLSBUF,   "log thread-local buffer");
  59
  60 DEFINE_HOOK(zlog_init, (const char *progname, const char *protoname,
  61                         unsigned short instance, uid_t uid, gid_t gid),
  62                        (progname, protoname, instance, uid, gid));
  63 DEFINE_KOOH(zlog_fini, (), ());
  64 DEFINE_HOOK(zlog_aux_init, (const char *prefix, int prio_min),
  65                            (prefix, prio_min));
  66
  67 char zlog_prefix[128];
  68 size_t zlog_prefixsz;
  69 int zlog_tmpdirfd = -1;
  70
  71 static atomic_bool zlog_ec = true, zlog_xid = true;
  72
  73 /* these are kept around because logging is initialized (and directories
  74  * & files created) before zprivs code switches to the FRR user;  therefore
  75  * we need to chown() things so we don't get permission errors later when
  76  * trying to delete things on shutdown
  77  */
  78 static uid_t zlog_uid = -1;
  79 static gid_t zlog_gid = -1;
  80
  81 DECLARE_ATOMLIST(zlog_targets, struct zlog_target, head);
  82 static struct zlog_targets_head zlog_targets;
  83
  84 /* cf. zlog.h for additional comments on this struct.
  85  *
  86  * Note: you MUST NOT pass the format string + va_list to non-FRR format
  87  * string functions (e.g. vsyslog, sd_journal_printv, ...) since FRR uses an
  88  * extended prinf() with additional formats (%pI4 and the like).
  89  *
  90  * Also remember to use va_copy() on args.
  91  */
  92
  93 struct zlog_msg {
  94         struct timespec ts;
  95         int prio;
  96
  97         const char *fmt;
  98         va_list args;
  99         const struct xref_logmsg *xref;
 100
 101         char *stackbuf;
 102         size_t stackbufsz;
 103         char *text;
 104         size_t textlen;
 105
 106         /* This is always ISO8601 with sub-second precision 9 here, it's
 107          * converted for callers as needed.  ts_dot points to the "."
 108          * separating sub-seconds.  ts_zonetail is "Z" or "+00:00" for the
 109          * local time offset.
 110          *
 111          * Valid if ZLOG_TS_ISO8601 is set.
 112          * (0 if timestamp has not been formatted yet)
 113          */
 114         uint32_t ts_flags;
 115         char ts_str[32], *ts_dot, ts_zonetail[8];
 116 };
 117
 118 /* thread-local log message buffering
 119  *
 120  * This is strictly optional and set up by calling zlog_tls_buffer_init()
 121  * on a particular thread.
 122  *
 123  * If in use, this will create a temporary file in /var/tmp which is used as
 124  * memory-mapped MAP_SHARED log message buffer.  The idea there is that buffer
 125  * access doesn't require any syscalls, but in case of a crash the kernel
 126  * knows to sync the memory back to disk.  This way the user can still get the
 127  * last log messages if there were any left unwritten in the buffer.
 128  *
 129  * Sizing this dynamically isn't particularly useful, so here's an 8k buffer
 130  * with a message limit of 64 messages.  Message metadata (e.g. priority,
 131  * timestamp) aren't in the mmap region, so they're lost on crash, but we can
 132  * live with that.
 133  */
 134
 135 #if defined(HAVE_OPENAT) && defined(HAVE_UNLINKAT)
 136 #define CAN_DO_TLS 1
 137 #endif
 138
 139 #define TLS_LOG_BUF_SIZE        8192
 140 #define TLS_LOG_MAXMSG          64
 141
 142 struct zlog_tls {
 143         char *mmbuf;
 144         size_t bufpos;
 145
 146         size_t nmsgs;
 147         struct zlog_msg msgs[TLS_LOG_MAXMSG];
 148         struct zlog_msg *msgp[TLS_LOG_MAXMSG];
 149 };
 150
 151 static inline void zlog_tls_free(void *arg);
 152
 153 /* proper ELF TLS is a bit faster than pthread_[gs]etspecific, so if it's
 154  * available we'll use it here
 155  */
 156
 157 #ifdef __OpenBSD__
 158 static pthread_key_t zlog_tls_key;
 159
 160 static void zlog_tls_key_init(void) __attribute__((_CONSTRUCTOR(500)));
 161 static void zlog_tls_key_init(void)
 162 {
 163         pthread_key_create(&zlog_tls_key, zlog_tls_free);
 164 }
 165
 166 static void zlog_tls_key_fini(void) __attribute__((_DESTRUCTOR(500)));
 167 static void zlog_tls_key_fini(void)
 168 {
 169         pthread_key_delete(zlog_tls_key);
 170 }
 171
 172 static inline struct zlog_tls *zlog_tls_get(void)
 173 {
 174         return pthread_getspecific(zlog_tls_key);
 175 }
 176
 177 static inline void zlog_tls_set(struct zlog_tls *val)
 178 {
 179         pthread_setspecific(zlog_tls_key, val);
 180 }
 181 #else
 182 # ifndef thread_local
 183 #  define thread_local __thread
 184 # endif
 185
 186 static thread_local struct zlog_tls *zlog_tls_var
 187         __attribute__((tls_model("initial-exec")));
 188
 189 static inline struct zlog_tls *zlog_tls_get(void)
 190 {
 191         return zlog_tls_var;
 192 }
 193
 194 static inline void zlog_tls_set(struct zlog_tls *val)
 195 {
 196         zlog_tls_var = val;
 197 }
 198 #endif
 199
 200 #ifdef CAN_DO_TLS
 201 static long zlog_gettid(void)
 202 {
 203         long rv = -1;
 204 #ifdef HAVE_PTHREAD_GETTHREADID_NP
 205         rv = pthread_getthreadid_np();
 206 #elif defined(linux)
 207         rv = syscall(__NR_gettid);
 208 #elif defined(__NetBSD__)
 209         rv = _lwp_self();
 210 #elif defined(__FreeBSD__)
 211         thr_self(&rv);
 212 #elif defined(__DragonFly__)
 213         rv = lwp_gettid();
 214 #elif defined(__OpenBSD__)
 215         rv = getthrid();
 216 #elif defined(__sun)
 217         rv = pthread_self();
 218 #elif defined(__APPLE__)
 219         rv = mach_thread_self();
 220         mach_port_deallocate(mach_task_self(), rv);
 221 #endif
 222         return rv;
 223 }
 224
 225 void zlog_tls_buffer_init(void)
 226 {
 227         struct zlog_tls *zlog_tls;
 228         char mmpath[MAXPATHLEN];
 229         int mmfd;
 230         size_t i;
 231
 232         zlog_tls = zlog_tls_get();
 233
 234         if (zlog_tls || zlog_tmpdirfd < 0)
 235                 return;
 236
 237         zlog_tls = XCALLOC(MTYPE_LOG_TLSBUF, sizeof(*zlog_tls));
 238         for (i = 0; i < array_size(zlog_tls->msgp); i++)
 239                 zlog_tls->msgp[i] = &zlog_tls->msgs[i];
 240
 241         snprintfrr(mmpath, sizeof(mmpath), "logbuf.%ld", zlog_gettid());
 242
 243         mmfd = openat(zlog_tmpdirfd, mmpath,
 244                       O_RDWR | O_CREAT | O_EXCL | O_CLOEXEC, 0600);
 245         if (mmfd < 0) {
 246                 zlog_err("failed to open thread log buffer \"%s\": %s",
 247                          mmpath, strerror(errno));
 248                 goto out_anon;
 249         }
 250         fchown(mmfd, zlog_uid, zlog_gid);
 251
 252 #ifdef HAVE_POSIX_FALLOCATE
 253         if (posix_fallocate(mmfd, 0, TLS_LOG_BUF_SIZE) != 0)
 254         /* note next statement is under above if() */
 255 #endif
 256         if (ftruncate(mmfd, TLS_LOG_BUF_SIZE) < 0) {
 257                 zlog_err("failed to allocate thread log buffer \"%s\": %s",
 258                          mmpath, strerror(errno));
 259                 goto out_anon_unlink;
 260         }
 261
 262         zlog_tls->mmbuf = mmap(NULL, TLS_LOG_BUF_SIZE, PROT_READ | PROT_WRITE,
 263                               MAP_SHARED, mmfd, 0);
 264         if (zlog_tls->mmbuf == MAP_FAILED) {
 265                 zlog_err("failed to mmap thread log buffer \"%s\": %s",
 266                          mmpath, strerror(errno));
 267                 goto out_anon_unlink;
 268         }
 269
 270         close(mmfd);
 271         zlog_tls_set(zlog_tls);
 272         return;
 273
 274 out_anon_unlink:
 275         unlink(mmpath);
 276         close(mmfd);
 277 out_anon:
 278
 279 #ifndef MAP_ANONYMOUS
 280 #define MAP_ANONYMOUS MAP_ANON
 281 #endif
 282         zlog_tls->mmbuf = mmap(NULL, TLS_LOG_BUF_SIZE, PROT_READ | PROT_WRITE,
 283                               MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
 284
 285         if (!zlog_tls->mmbuf) {
 286                 zlog_err("failed to anonymous-mmap thread log buffer: %s",
 287                          strerror(errno));
 288                 XFREE(MTYPE_LOG_TLSBUF, zlog_tls);
 289                 zlog_tls_set(NULL);
 290                 return;
 291         }
 292
 293         zlog_tls_set(zlog_tls);
 294 }
 295
 296 void zlog_tls_buffer_fini(void)
 297 {
 298         char mmpath[MAXPATHLEN];
 299
 300         zlog_tls_buffer_flush();
 301
 302         zlog_tls_free(zlog_tls_get());
 303         zlog_tls_set(NULL);
 304
 305         snprintfrr(mmpath, sizeof(mmpath), "logbuf.%ld", zlog_gettid());
 306         if (unlinkat(zlog_tmpdirfd, mmpath, 0))
 307                 zlog_err("unlink logbuf: %s (%d)", strerror(errno), errno);
 308 }
 309
 310 #else /* !CAN_DO_TLS */
 311 void zlog_tls_buffer_init(void)
 312 {
 313 }
 314
 315 void zlog_tls_buffer_fini(void)
 316 {
 317 }
 318 #endif
 319
 320 static inline void zlog_tls_free(void *arg)
 321 {
 322         struct zlog_tls *zlog_tls = arg;
 323
 324         if (!zlog_tls)
 325                 return;
 326
 327         munmap(zlog_tls->mmbuf, TLS_LOG_BUF_SIZE);
 328         XFREE(MTYPE_LOG_TLSBUF, zlog_tls);
 329 }
 330
 331 void zlog_tls_buffer_flush(void)
 332 {
 333         struct zlog_target *zt;
 334         struct zlog_tls *zlog_tls = zlog_tls_get();
 335
 336         if (!zlog_tls)
 337                 return;
 338         if (!zlog_tls->nmsgs)
 339                 return;
 340
 341         rcu_read_lock();
 342         frr_each (zlog_targets, &zlog_targets, zt) {
 343                 if (!zt->logfn)
 344                         continue;
 345
 346                 zt->logfn(zt, zlog_tls->msgp, zlog_tls->nmsgs);
 347         }
 348         rcu_read_unlock();
 349
 350         zlog_tls->bufpos = 0;
 351         zlog_tls->nmsgs = 0;
 352 }
 353
 354
 355 static void vzlog_notls(const struct xref_logmsg *xref, int prio,
 356                         const char *fmt, va_list ap)
 357 {
 358         struct zlog_target *zt;
 359         struct zlog_msg stackmsg = {
 360                 .prio = prio & LOG_PRIMASK,
 361                 .fmt = fmt,
 362                 .xref = xref,
 363         }, *msg = &stackmsg;
 364         char stackbuf[512];
 365
 366         clock_gettime(CLOCK_REALTIME, &msg->ts);
 367         va_copy(msg->args, ap);
 368         msg->stackbuf = stackbuf;
 369         msg->stackbufsz = sizeof(stackbuf);
 370
 371         rcu_read_lock();
 372         frr_each (zlog_targets, &zlog_targets, zt) {
 373                 if (prio > zt->prio_min)
 374                         continue;
 375                 if (!zt->logfn)
 376                         continue;
 377
 378                 zt->logfn(zt, &msg, 1);
 379         }
 380         rcu_read_unlock();
 381
 382         va_end(msg->args);
 383         if (msg->text && msg->text != stackbuf)
 384                 XFREE(MTYPE_LOG_MESSAGE, msg->text);
 385 }
 386
 387 static void vzlog_tls(struct zlog_tls *zlog_tls, const struct xref_logmsg *xref,
 388                       int prio, const char *fmt, va_list ap)
 389 {
 390         struct zlog_target *zt;
 391         struct zlog_msg *msg;
 392         char *buf;
 393         bool ignoremsg = true;
 394         bool immediate = false;
 395
 396         /* avoid further processing cost if no target wants this message */
 397         rcu_read_lock();
 398         frr_each (zlog_targets, &zlog_targets, zt) {
 399                 if (prio > zt->prio_min)
 400                         continue;
 401                 ignoremsg = false;
 402                 break;
 403         }
 404         rcu_read_unlock();
 405
 406         if (ignoremsg)
 407                 return;
 408
 409         msg = &zlog_tls->msgs[zlog_tls->nmsgs];
 410         zlog_tls->nmsgs++;
 411         if (zlog_tls->nmsgs == array_size(zlog_tls->msgs))
 412                 immediate = true;
 413
 414         memset(msg, 0, sizeof(*msg));
 415         clock_gettime(CLOCK_REALTIME, &msg->ts);
 416         va_copy(msg->args, ap);
 417         msg->stackbuf = buf = zlog_tls->mmbuf + zlog_tls->bufpos;
 418         msg->stackbufsz = TLS_LOG_BUF_SIZE - zlog_tls->bufpos - 1;
 419         msg->fmt = fmt;
 420         msg->prio = prio & LOG_PRIMASK;
 421         msg->xref = xref;
 422         if (msg->prio < LOG_INFO)
 423                 immediate = true;
 424
 425         if (!immediate) {
 426                 /* messages written later need to take the formatting cost
 427                  * immediately since we can't hold a reference on varargs
 428                  */
 429                 zlog_msg_text(msg, NULL);
 430
 431                 if (msg->text != buf)
 432                         /* zlog_msg_text called malloc() on us :( */
 433                         immediate = true;
 434                 else {
 435                         zlog_tls->bufpos += msg->textlen + 1;
 436                         /* write a second \0 to mark current end position
 437                          * (in case of crash this signals end of unwritten log
 438                          * messages in mmap'd logbuf file)
 439                          */
 440                         zlog_tls->mmbuf[zlog_tls->bufpos] = '\0';
 441
 442                         /* avoid malloc() for next message */
 443                         if (TLS_LOG_BUF_SIZE - zlog_tls->bufpos < 256)
 444                                 immediate = true;
 445                 }
 446         }
 447
 448         if (immediate)
 449                 zlog_tls_buffer_flush();
 450
 451         va_end(msg->args);
 452         if (msg->text && msg->text != buf)
 453                 XFREE(MTYPE_LOG_MESSAGE, msg->text);
 454 }
 455
 456 void vzlogx(const struct xref_logmsg *xref, int prio,
 457             const char *fmt, va_list ap)
 458 {
 459         struct zlog_tls *zlog_tls = zlog_tls_get();
 460
 461 #ifdef HAVE_LTTNG
 462         va_list copy;
 463         va_copy(copy, ap);
 464         char *msg = vasprintfrr(MTYPE_LOG_MESSAGE, fmt, copy);
 465
 466         switch (prio) {
 467         case LOG_ERR:
 468                 frrtracelog(TRACE_ERR, msg);
 469                 break;
 470         case LOG_WARNING:
 471                 frrtracelog(TRACE_WARNING, msg);
 472                 break;
 473         case LOG_DEBUG:
 474                 frrtracelog(TRACE_DEBUG, msg);
 475                 break;
 476         case LOG_NOTICE:
 477                 frrtracelog(TRACE_DEBUG, msg);
 478                 break;
 479         case LOG_INFO:
 480         default:
 481                 frrtracelog(TRACE_INFO, msg);
 482                 break;
 483         }
 484
 485         va_end(copy);
 486         XFREE(MTYPE_LOG_MESSAGE, msg);
 487 #endif
 488
 489         if (zlog_tls)
 490                 vzlog_tls(zlog_tls, xref, prio, fmt, ap);
 491         else
 492                 vzlog_notls(xref, prio, fmt, ap);
 493 }
 494
 495 void zlog_sigsafe(const char *text, size_t len)
 496 {
 497         struct zlog_target *zt;
 498         const char *end = text + len, *nlpos;
 499
 500         while (text < end) {
 501                 nlpos = memchr(text, '\n', end - text);
 502                 if (!nlpos)
 503                         nlpos = end;
 504
 505                 frr_each (zlog_targets, &zlog_targets, zt) {
 506                         if (LOG_CRIT > zt->prio_min)
 507                                 continue;
 508                         if (!zt->logfn_sigsafe)
 509                                 continue;
 510
 511                         zt->logfn_sigsafe(zt, text, nlpos - text);
 512                 }
 513
 514                 if (nlpos == end)
 515                         break;
 516                 text = nlpos + 1;
 517         }
 518 }
 519
 520
 521 int zlog_msg_prio(struct zlog_msg *msg)
 522 {
 523         return msg->prio;
 524 }
 525
 526 const struct xref_logmsg *zlog_msg_xref(struct zlog_msg *msg)
 527 {
 528         return msg->xref;
 529 }
 530
 531 const char *zlog_msg_text(struct zlog_msg *msg, size_t *textlen)
 532 {
 533         if (!msg->text) {
 534                 va_list args;
 535                 bool do_xid, do_ec;
 536                 size_t need = 0, hdrlen;
 537                 struct fbuf fb = {
 538                         .buf = msg->stackbuf,
 539                         .pos = msg->stackbuf,
 540                         .len = msg->stackbufsz,
 541                 };
 542
 543                 do_ec = atomic_load_explicit(&zlog_ec, memory_order_relaxed);
 544                 do_xid = atomic_load_explicit(&zlog_xid, memory_order_relaxed);
 545
 546                 if (msg->xref && do_xid && msg->xref->xref.xrefdata->uid[0]) {
 547                         need += bputch(&fb, '[');
 548                         need += bputs(&fb, msg->xref->xref.xrefdata->uid);
 549                         need += bputch(&fb, ']');
 550                 }
 551                 if (msg->xref && do_ec && msg->xref->ec)
 552                         need += bprintfrr(&fb, "[EC %u]", msg->xref->ec);
 553                 if (need)
 554                         need += bputch(&fb, ' ');
 555
 556                 hdrlen = need;
 557                 assert(hdrlen < msg->stackbufsz);
 558
 559                 va_copy(args, msg->args);
 560                 need += vbprintfrr(&fb, msg->fmt, args);
 561                 va_end(args);
 562
 563                 msg->textlen = need;
 564                 need += bputch(&fb, '\0');
 565
 566                 if (need <= msg->stackbufsz)
 567                         msg->text = msg->stackbuf;
 568                 else {
 569                         msg->text = XMALLOC(MTYPE_LOG_MESSAGE, need);
 570
 571                         memcpy(msg->text, msg->stackbuf, hdrlen);
 572
 573                         fb.buf = msg->text;
 574                         fb.len = need;
 575                         fb.pos = msg->text + hdrlen;
 576
 577                         va_copy(args, msg->args);
 578                         vbprintfrr(&fb, msg->fmt, args);
 579                         va_end(args);
 580
 581                         bputch(&fb, '\0');
 582                 }
 583         }
 584         if (textlen)
 585                 *textlen = msg->textlen;
 586         return msg->text;
 587 }
 588
 589 #define ZLOG_TS_FORMAT          (ZLOG_TS_ISO8601 | ZLOG_TS_LEGACY)
 590 #define ZLOG_TS_FLAGS           ~ZLOG_TS_PREC
 591
 592 size_t zlog_msg_ts(struct zlog_msg *msg, char *out, size_t outsz,
 593                    uint32_t flags)
 594 {
 595         size_t len1;
 596
 597         if (!(flags & ZLOG_TS_FORMAT))
 598                 return 0;
 599
 600         if (!(msg->ts_flags & ZLOG_TS_FORMAT) ||
 601             ((msg->ts_flags ^ flags) & ZLOG_TS_UTC)) {
 602                 struct tm tm;
 603
 604                 if (flags & ZLOG_TS_UTC)
 605                         gmtime_r(&msg->ts.tv_sec, &tm);
 606                 else
 607                         localtime_r(&msg->ts.tv_sec, &tm);
 608
 609                 strftime(msg->ts_str, sizeof(msg->ts_str),
 610                          "%Y-%m-%dT%H:%M:%S", &tm);
 611
 612                 if (flags & ZLOG_TS_UTC) {
 613                         msg->ts_zonetail[0] = 'Z';
 614                         msg->ts_zonetail[1] = '\0';
 615                 } else
 616                         snprintfrr(msg->ts_zonetail, sizeof(msg->ts_zonetail),
 617                                    "%+03d:%02d",
 618                                    (int)(tm.tm_gmtoff / 3600),
 619                                    (int)(labs(tm.tm_gmtoff) / 60) % 60);
 620
 621                 msg->ts_dot = msg->ts_str + strlen(msg->ts_str);
 622                 snprintfrr(msg->ts_dot,
 623                            msg->ts_str + sizeof(msg->ts_str) - msg->ts_dot,
 624                            ".%09lu", (unsigned long)msg->ts.tv_nsec);
 625
 626                 msg->ts_flags = ZLOG_TS_ISO8601 | (flags & ZLOG_TS_UTC);
 627         }
 628
 629         len1 = flags & ZLOG_TS_PREC;
 630         len1 = (msg->ts_dot - msg->ts_str) + (len1 ? len1 + 1 : 0);
 631
 632         if (len1 > strlen(msg->ts_str))
 633                 len1 = strlen(msg->ts_str);
 634
 635         if (flags & ZLOG_TS_LEGACY) {
 636                 if (len1 + 1 > outsz)
 637                         return 0;
 638
 639                 /* just swap out the formatting, faster than redoing it */
 640                 for (char *p = msg->ts_str; p < msg->ts_str + len1; p++) {
 641                         switch (*p) {
 642                         case '-':
 643                                 *out++ = '/';
 644                                 break;
 645                         case 'T':
 646                                 *out++ = ' ';
 647                                 break;
 648                         default:
 649                                 *out++ = *p;
 650                         }
 651                 }
 652                 *out = '\0';
 653                 return len1;
 654         } else {
 655                 size_t len2 = strlen(msg->ts_zonetail);
 656
 657                 if (len1 + len2 + 1 > outsz)
 658                         return 0;
 659                 memcpy(out, msg->ts_str, len1);
 660                 memcpy(out + len1, msg->ts_zonetail, len2);
 661                 out[len1 + len2] = '\0';
 662                 return len1 + len2;
 663         }
 664 }
 665
 666 void zlog_set_prefix_ec(bool enable)
 667 {
 668         atomic_store_explicit(&zlog_ec, enable, memory_order_relaxed);
 669 }
 670
 671 bool zlog_get_prefix_ec(void)
 672 {
 673         return atomic_load_explicit(&zlog_ec, memory_order_relaxed);
 674 }
 675
 676 void zlog_set_prefix_xid(bool enable)
 677 {
 678         atomic_store_explicit(&zlog_xid, enable, memory_order_relaxed);
 679 }
 680
 681 bool zlog_get_prefix_xid(void)
 682 {
 683         return atomic_load_explicit(&zlog_xid, memory_order_relaxed);
 684 }
 685
 686 /* setup functions */
 687
 688 struct zlog_target *zlog_target_clone(struct memtype *mt,
 689                                       struct zlog_target *oldzt, size_t size)
 690 {
 691         struct zlog_target *newzt;
 692
 693         newzt = XCALLOC(mt, size);
 694         if (oldzt) {
 695                 newzt->prio_min = oldzt->prio_min;
 696                 newzt->logfn = oldzt->logfn;
 697                 newzt->logfn_sigsafe = oldzt->logfn_sigsafe;
 698         }
 699
 700         return newzt;
 701 }
 702
 703 struct zlog_target *zlog_target_replace(struct zlog_target *oldzt,
 704                                         struct zlog_target *newzt)
 705 {
 706         if (newzt)
 707                 zlog_targets_add_tail(&zlog_targets, newzt);
 708         if (oldzt)
 709                 zlog_targets_del(&zlog_targets, oldzt);
 710         return oldzt;
 711 }
 712
 713
 714 /* common init */
 715
 716 #define TMPBASEDIR "/var/tmp/frr"
 717
 718 static char zlog_tmpdir[MAXPATHLEN];
 719
 720 void zlog_aux_init(const char *prefix, int prio_min)
 721 {
 722         if (prefix)
 723                 strlcpy(zlog_prefix, prefix, sizeof(zlog_prefix));
 724
 725         hook_call(zlog_aux_init, prefix, prio_min);
 726 }
 727
 728 void zlog_init(const char *progname, const char *protoname,
 729                unsigned short instance, uid_t uid, gid_t gid)
 730 {
 731         zlog_uid = uid;
 732         zlog_gid = gid;
 733
 734         if (instance) {
 735                 snprintfrr(zlog_tmpdir, sizeof(zlog_tmpdir),
 736                            "/var/tmp/frr/%s-%d.%ld",
 737                            progname, instance, (long)getpid());
 738
 739                 zlog_prefixsz = snprintfrr(zlog_prefix, sizeof(zlog_prefix),
 740                                            "%s[%d]: ", protoname, instance);
 741         } else {
 742                 snprintfrr(zlog_tmpdir, sizeof(zlog_tmpdir),
 743                            "/var/tmp/frr/%s.%ld",
 744                            progname, (long)getpid());
 745
 746                 zlog_prefixsz = snprintfrr(zlog_prefix, sizeof(zlog_prefix),
 747                                            "%s: ", protoname);
 748         }
 749
 750         if (mkdir(TMPBASEDIR, 0700) != 0) {
 751                 if (errno != EEXIST) {
 752                         zlog_err("failed to mkdir \"%s\": %s",
 753                                  TMPBASEDIR, strerror(errno));
 754                         goto out_warn;
 755                 }
 756         }
 757         chown(TMPBASEDIR, zlog_uid, zlog_gid);
 758
 759         if (mkdir(zlog_tmpdir, 0700) != 0) {
 760                 zlog_err("failed to mkdir \"%s\": %s",
 761                          zlog_tmpdir, strerror(errno));
 762                 goto out_warn;
 763         }
 764
 765 #ifdef O_PATH
 766         zlog_tmpdirfd = open(zlog_tmpdir,
 767                              O_PATH | O_RDONLY | O_CLOEXEC);
 768 #else
 769         zlog_tmpdirfd = open(zlog_tmpdir,
 770                              O_DIRECTORY | O_RDONLY | O_CLOEXEC);
 771 #endif
 772         if (zlog_tmpdirfd < 0) {
 773                 zlog_err("failed to open \"%s\": %s",
 774                          zlog_tmpdir, strerror(errno));
 775                 goto out_warn;
 776         }
 777
 778 #ifdef AT_EMPTY_PATH
 779         fchownat(zlog_tmpdirfd, "", zlog_uid, zlog_gid, AT_EMPTY_PATH);
 780 #else
 781         chown(zlog_tmpdir, zlog_uid, zlog_gid);
 782 #endif
 783
 784         hook_call(zlog_init, progname, protoname, instance, uid, gid);
 785         return;
 786
 787 out_warn:
 788         zlog_err("crashlog and per-thread log buffering unavailable!");
 789         hook_call(zlog_init, progname, protoname, instance, uid, gid);
 790 }
 791
 792 void zlog_fini(void)
 793 {
 794         hook_call(zlog_fini);
 795
 796         if (zlog_tmpdirfd >= 0) {
 797                 close(zlog_tmpdirfd);
 798                 zlog_tmpdirfd = -1;
 799
 800                 if (rmdir(zlog_tmpdir))
 801                         zlog_err("failed to rmdir \"%s\": %s",
 802                                  zlog_tmpdir, strerror(errno));
 803         }
 804 }