usr.bin/ar/write.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2007 Kai Wang
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD$");
  31
  32 #include <sys/endian.h>
  33 #include <sys/mman.h>
  34 #include <sys/queue.h>
  35 #include <sys/stat.h>
  36 #include <archive.h>
  37 #include <archive_entry.h>
  38 #include <assert.h>
  39 #include <errno.h>
  40 #include <fcntl.h>
  41 #include <gelf.h>
  42 #include <libgen.h>
  43 #include <stdio.h>
  44 #include <stdlib.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #include "ar.h"
  49
  50 #define _ARMAG_LEN 8            /* length of ar magic string */
  51 #define _ARHDR_LEN 60           /* length of ar header */
  52 #define _INIT_AS_CAP 128        /* initial archive string table size */
  53 #define _INIT_SYMOFF_CAP (256*(sizeof(uint64_t))) /* initial so table size */
  54 #define _INIT_SYMNAME_CAP 1024                    /* initial sn table size */
  55 #define _MAXNAMELEN_SVR4 15     /* max member name length in svr4 variant */
  56 #define _TRUNCATE_LEN 15        /* number of bytes to keep for member name */
  57
  58 static void     add_to_ar_str_table(struct bsdar *bsdar, const char *name);
  59 static void     add_to_ar_sym_table(struct bsdar *bsdar, const char *name);
  60 static struct ar_obj    *create_obj_from_file(struct bsdar *bsdar,
  61                     const char *name, time_t mtime);
  62 static void     create_symtab_entry(struct bsdar *bsdar, void *maddr,
  63                     size_t size);
  64 static void     free_obj(struct bsdar *bsdar, struct ar_obj *obj);
  65 static void     insert_obj(struct bsdar *bsdar, struct ar_obj *obj,
  66                     struct ar_obj *pos);
  67 static void     prefault_buffer(const char *buf, size_t s);
  68 static void     read_objs(struct bsdar *bsdar, const char *archive,
  69                     int checkargv);
  70 static void     write_cleanup(struct bsdar *bsdar);
  71 static void     write_data(struct bsdar *bsdar, struct archive *a,
  72                     const void *buf, size_t s);
  73 static void     write_objs(struct bsdar *bsdar);
  74
  75 /*
  76  * Create object from file, return created obj upon success, or NULL
  77  * when an error occurs or the member is not newer than existing
  78  * one while -u is specified.
  79  */
  80 static struct ar_obj *
  81 create_obj_from_file(struct bsdar *bsdar, const char *name, time_t mtime)
  82 {
  83         struct ar_obj           *obj;
  84         struct stat              sb;
  85         const char              *bname;
  86         char                    *tmpname;
  87
  88         if (name == NULL)
  89                 return (NULL);
  90
  91         obj = malloc(sizeof(struct ar_obj));
  92         if (obj == NULL)
  93                 bsdar_errc(bsdar, errno, "malloc failed");
  94         if ((obj->fd = open(name, O_RDONLY, 0)) < 0) {
  95                 bsdar_warnc(bsdar, errno, "can't open file: %s", name);
  96                 free(obj);
  97                 return (NULL);
  98         }
  99
 100         tmpname = strdup(name);
 101         if (tmpname == NULL)
 102                 bsdar_errc(bsdar, errno, "strdup failed");
 103         if ((bname = basename(tmpname)) == NULL)
 104                 bsdar_errc(bsdar, errno, "basename failed");
 105         if (bsdar->options & AR_TR && strlen(bname) > _TRUNCATE_LEN) {
 106                 if ((obj->name = malloc(_TRUNCATE_LEN + 1)) == NULL)
 107                         bsdar_errc(bsdar, errno, "malloc failed");
 108                 (void)strncpy(obj->name, bname, _TRUNCATE_LEN);
 109                 obj->name[_TRUNCATE_LEN] = '\0';
 110         } else
 111                 if ((obj->name = strdup(bname)) == NULL)
 112                     bsdar_errc(bsdar, errno, "strdup failed");
 113         free(tmpname);
 114
 115         if (fstat(obj->fd, &sb) < 0) {
 116                 bsdar_warnc(bsdar, errno, "can't fstat file: %s", obj->name);
 117                 goto giveup;
 118         }
 119         if (!S_ISREG(sb.st_mode)) {
 120                 bsdar_warnc(bsdar, 0, "%s is not an ordinary file", obj->name);
 121                 goto giveup;
 122         }
 123
 124         /*
 125          * When option '-u' is specified and member is not newer than the
 126          * existing one, the replace will not happen. While if mtime == 0,
 127          * which indicates that this is to "replace a none exist member",
 128          * the replace will proceed regardless of '-u'.
 129          */
 130         if (mtime != 0 && bsdar->options & AR_U && sb.st_mtime <= mtime)
 131                 goto giveup;
 132
 133         /*
 134          * When option '-D' is specified, mtime and UID / GID from the file
 135          * will be replaced with 0, and file mode with 644. This ensures that
 136          * checksums will match for two archives containing the exact same
 137          * files.
 138          */
 139         if (bsdar->options & AR_D) {
 140                 obj->uid = 0;
 141                 obj->gid = 0;
 142                 obj->mtime = 0;
 143                 obj->md = S_IFREG | 0644;
 144         } else {
 145                 obj->uid = sb.st_uid;
 146                 obj->gid = sb.st_gid;
 147                 obj->mtime = sb.st_mtime;
 148                 obj->md = sb.st_mode;
 149         }
 150         obj->size = sb.st_size;
 151         obj->dev = sb.st_dev;
 152         obj->ino = sb.st_ino;
 153
 154         if (obj->size == 0) {
 155                 obj->maddr = NULL;
 156                 return (obj);
 157         }
 158
 159         if ((obj->maddr = mmap(NULL, obj->size, PROT_READ,
 160             MAP_PRIVATE, obj->fd, (off_t)0)) == MAP_FAILED) {
 161                 bsdar_warnc(bsdar, errno, "can't mmap file: %s", obj->name);
 162                 goto giveup;
 163         }
 164         if (close(obj->fd) < 0)
 165                 bsdar_errc(bsdar, errno, "close failed: %s",
 166                     obj->name);
 167
 168         return (obj);
 169
 170 giveup:
 171         if (close(obj->fd) < 0)
 172                 bsdar_errc(bsdar, errno, "close failed: %s",
 173                     obj->name);
 174         free(obj->name);
 175         free(obj);
 176         return (NULL);
 177 }
 178
 179 /*
 180  * Free object itself and its associated allocations.
 181  */
 182 static void
 183 free_obj(struct bsdar *bsdar, struct ar_obj *obj)
 184 {
 185         if (obj->fd == -1)
 186                 free(obj->maddr);
 187         else
 188                 if (obj->maddr != NULL && munmap(obj->maddr, obj->size))
 189                         bsdar_warnc(bsdar, errno,
 190                             "can't munmap file: %s", obj->name);
 191         free(obj->name);
 192         free(obj);
 193 }
 194
 195 /*
 196  * Insert obj to the tail, or before/after the pos obj.
 197  */
 198 static void
 199 insert_obj(struct bsdar *bsdar, struct ar_obj *obj, struct ar_obj *pos)
 200 {
 201         if (obj == NULL)
 202                 bsdar_errc(bsdar, 0, "try to insert a null obj");
 203
 204         if (pos == NULL || obj == pos)
 205                 /*
 206                  * If the object to move happens to be the position obj,
 207                  * or if there is not a pos obj, move it to tail.
 208                  */
 209                 goto tail;
 210
 211         if (bsdar->options & AR_B) {
 212                 TAILQ_INSERT_BEFORE(pos, obj, objs);
 213                 return;
 214         }
 215         if (bsdar->options & AR_A) {
 216                 TAILQ_INSERT_AFTER(&bsdar->v_obj, pos, obj, objs);
 217                 return;
 218         }
 219
 220 tail:
 221         TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
 222
 223 }
 224
 225 /*
 226  * Read objects from archive into v_obj list. Note that checkargv is
 227  * set when read_objs is used to read objects from the target of
 228  * ADDLIB command (ar script mode), in this case argv array possibly
 229  * specifies the members ADDLIB want.
 230  */
 231 static void
 232 read_objs(struct bsdar *bsdar, const char *archive, int checkargv)
 233 {
 234         struct archive           *a;
 235         struct archive_entry     *entry;
 236         struct ar_obj            *obj;
 237         const char               *name;
 238         const char               *bname;
 239         char                     *buff;
 240         char                    **av;
 241         size_t                    size;
 242         int                       i, r, find;
 243
 244         if ((a = archive_read_new()) == NULL)
 245                 bsdar_errc(bsdar, 0, "archive_read_new failed");
 246         archive_read_support_format_ar(a);
 247         AC(archive_read_open_filename(a, archive, DEF_BLKSZ));
 248         for (;;) {
 249                 r = archive_read_next_header(a, &entry);
 250                 if (r == ARCHIVE_FATAL)
 251                         bsdar_errc(bsdar, archive_errno(a), "%s",
 252                             archive_error_string(a));
 253                 if (r == ARCHIVE_EOF)
 254                         break;
 255                 if (r == ARCHIVE_WARN || r == ARCHIVE_RETRY)
 256                         bsdar_warnc(bsdar, archive_errno(a), "%s",
 257                             archive_error_string(a));
 258                 if (r == ARCHIVE_RETRY) {
 259                         bsdar_warnc(bsdar, 0, "Retrying...");
 260                         continue;
 261                 }
 262
 263                 name = archive_entry_pathname(entry);
 264
 265                 /*
 266                  * skip pseudo members.
 267                  */
 268                 if (strcmp(name, "/") == 0 || strcmp(name, "//") == 0)
 269                         continue;
 270
 271                 /*
 272                  * If checkargv is set, only read those members specified
 273                  * in argv.
 274                  */
 275                 if (checkargv && bsdar->argc > 0) {
 276                         find = 0;
 277                         for(i = 0; i < bsdar->argc; i++) {
 278                                 av = &bsdar->argv[i];
 279                                 if (*av == NULL)
 280                                         continue;
 281                                 if ((bname = basename(*av)) == NULL)
 282                                         bsdar_errc(bsdar, errno,
 283                                             "basename failed");
 284                                 if (strcmp(bname, name) != 0)
 285                                         continue;
 286
 287                                 *av = NULL;
 288                                 find = 1;
 289                                 break;
 290                         }
 291                         if (!find)
 292                                 continue;
 293                 }
 294
 295                 size = archive_entry_size(entry);
 296
 297                 if (size > 0) {
 298                         if ((buff = malloc(size)) == NULL)
 299                                 bsdar_errc(bsdar, errno, "malloc failed");
 300                         if (archive_read_data(a, buff, size) != (ssize_t)size) {
 301                                 bsdar_warnc(bsdar, archive_errno(a), "%s",
 302                                     archive_error_string(a));
 303                                 free(buff);
 304                                 continue;
 305                         }
 306                 } else
 307                         buff = NULL;
 308
 309                 obj = malloc(sizeof(struct ar_obj));
 310                 if (obj == NULL)
 311                         bsdar_errc(bsdar, errno, "malloc failed");
 312                 obj->maddr = buff;
 313                 if ((obj->name = strdup(name)) == NULL)
 314                         bsdar_errc(bsdar, errno, "strdup failed");
 315                 obj->size = size;
 316                 obj->uid = archive_entry_uid(entry);
 317                 obj->gid = archive_entry_gid(entry);
 318                 obj->md = archive_entry_mode(entry);
 319                 obj->mtime = archive_entry_mtime(entry);
 320                 obj->dev = 0;
 321                 obj->ino = 0;
 322
 323                 /*
 324                  * Objects from archive have obj->fd set to -1,
 325                  * for the ease of cleaning up.
 326                  */
 327                 obj->fd = -1;
 328                 TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
 329         }
 330         AC(archive_read_close(a));
 331         AC(archive_read_free(a));
 332 }
 333
 334 /*
 335  * Determine the constitution of resulting archive.
 336  */
 337 int
 338 ar_write_archive(struct bsdar *bsdar, int mode)
 339 {
 340         struct ar_obj            *nobj, *obj, *obj_temp, *pos;
 341         struct stat               sb;
 342         const char               *bname;
 343         char                    **av;
 344         int                       exitcode, i;
 345
 346         TAILQ_INIT(&bsdar->v_obj);
 347         exitcode = EXIT_SUCCESS;
 348         nobj = NULL;
 349         pos = NULL;
 350         memset(&sb, 0, sizeof(sb));
 351
 352         assert(mode == 'A' || mode == 'd' || mode == 'm' || mode == 'q' ||
 353             mode == 'r' || mode == 's');
 354
 355         /*
 356          * Test if the specified archive exists, to figure out
 357          * whether we are creating one here.
 358          */
 359         if (stat(bsdar->filename, &sb) != 0) {
 360                 if (errno != ENOENT) {
 361                         bsdar_warnc(bsdar, 0, "stat %s failed",
 362                             bsdar->filename);
 363                         return (EXIT_FAILURE);
 364                 }
 365
 366                 /* We do not create archive in mode 'd', 'm' and 's'.  */
 367                 if (mode != 'r' && mode != 'q') {
 368                         bsdar_warnc(bsdar, 0, "%s: no such file",
 369                             bsdar->filename);
 370                         return (EXIT_FAILURE);
 371                 }
 372
 373                 /* Issue a warning if -c is not specified when creating. */
 374                 if (!(bsdar->options & AR_C))
 375                         bsdar_warnc(bsdar, 0, "creating %s", bsdar->filename);
 376                 goto new_archive;
 377         }
 378
 379         /*
 380          * First read members from existing archive.
 381          */
 382         read_objs(bsdar, bsdar->filename, 0);
 383
 384         /*
 385          * For mode 's', no member will be moved, deleted or replaced.
 386          */
 387         if (mode == 's')
 388                 goto write_objs;
 389
 390         /*
 391          * For mode 'q', we don't need to adjust existing members either.
 392          * Also, -a, -b and -i are ignored in this mode. New members are
 393          * always inserted at tail.
 394          */
 395         if (mode == 'q')
 396                 goto new_archive;
 397
 398         /*
 399          * Mode 'A' adds the contents of another archive to the tail of
 400          * current archive. Note that mode 'A' is a special mode for the
 401          * ADDLIB command of the ar script mode. Currently there is no
 402          * access to this function from the ar command line mode.
 403          */
 404         if (mode == 'A') {
 405                 /*
 406                  * Read objects from the target archive of ADDLIB command.
 407                  * If there are members specified in argv, read those members
 408                  * only, otherwise the entire archive will be read.
 409                  */
 410                 read_objs(bsdar, bsdar->addlib, 1);
 411                 goto write_objs;
 412         }
 413
 414         /*
 415          * Try to find the position member specified by user.
 416          */
 417         if (bsdar->options & AR_A || bsdar->options & AR_B) {
 418                 TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 419                         if (strcmp(obj->name, bsdar->posarg) == 0) {
 420                                 pos = obj;
 421                                 break;
 422                         }
 423                 }
 424
 425                 /*
 426                  * If can't find `pos' specified by user,
 427                  * silently insert objects at tail.
 428                  */
 429                 if (pos == NULL)
 430                         bsdar->options &= ~(AR_A | AR_B);
 431         }
 432
 433         for (i = 0; i < bsdar->argc; i++) {
 434                 av = &bsdar->argv[i];
 435
 436                 TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
 437                         if ((bname = basename(*av)) == NULL)
 438                                 bsdar_errc(bsdar, errno, "basename failed");
 439                         if (bsdar->options & AR_TR) {
 440                                 if (strncmp(bname, obj->name, _TRUNCATE_LEN))
 441                                         continue;
 442                         } else
 443                                 if (strcmp(bname, obj->name) != 0)
 444                                         continue;
 445
 446                         if (mode == 'r') {
 447                                 /*
 448                                  * if the new member is not qualified
 449                                  * to replace the old one, skip it.
 450                                  */
 451                                 nobj = create_obj_from_file(bsdar, *av,
 452                                     obj->mtime);
 453                                 if (nobj == NULL) {
 454                                         exitcode = EXIT_FAILURE;
 455                                         goto skip_obj;
 456                                 }
 457                         }
 458
 459                         if (bsdar->options & AR_V)
 460                                 (void)fprintf(stdout, "%c - %s\n", mode,
 461                                     *av);
 462
 463                         TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
 464                         if (mode == 'd' || mode == 'r')
 465                                 free_obj(bsdar, obj);
 466
 467                         if (mode == 'm')
 468                                 insert_obj(bsdar, obj, pos);
 469                         if (mode == 'r')
 470                                 insert_obj(bsdar, nobj, pos);
 471
 472                 skip_obj:
 473                         *av = NULL;
 474                         break;
 475                 }
 476
 477         }
 478
 479 new_archive:
 480         /*
 481          * When operating in mode 'r', directly add those user specified
 482          * objects which do not exist in current archive. When operating
 483          * in mode 'q', all objects specified in command line args are
 484          * appended to the archive, without comparing with existing ones.
 485          */
 486         for (i = 0; i < bsdar->argc; i++) {
 487                 av = &bsdar->argv[i];
 488                 if (*av != NULL && (mode == 'r' || mode == 'q')) {
 489                         nobj = create_obj_from_file(bsdar, *av, 0);
 490                         if (nobj == NULL) {
 491                                 exitcode = EXIT_FAILURE;
 492                                 *av = NULL;
 493                                 continue;
 494                         }
 495                         insert_obj(bsdar, nobj, pos);
 496                         if (bsdar->options & AR_V && nobj != NULL)
 497                                 (void)fprintf(stdout, "a - %s\n", *av);
 498                         *av = NULL;
 499                 }
 500         }
 501
 502 write_objs:
 503         write_objs(bsdar);
 504         write_cleanup(bsdar);
 505
 506         return (exitcode);
 507 }
 508
 509 /*
 510  * Memory cleaning up.
 511  */
 512 static void
 513 write_cleanup(struct bsdar *bsdar)
 514 {
 515         struct ar_obj           *obj, *obj_temp;
 516
 517         TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
 518                 TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
 519                 free_obj(bsdar, obj);
 520         }
 521
 522         free(bsdar->as);
 523         free(bsdar->s_so);
 524         free(bsdar->s_sn);
 525         bsdar->as = NULL;
 526         bsdar->s_so = NULL;
 527         bsdar->s_so_max = 0;
 528         bsdar->s_sn = NULL;
 529 }
 530
 531 /*
 532  * Fault in the buffer prior to writing as a workaround for poor performance
 533  * due to interaction with kernel fs deadlock avoidance code. See the comment
 534  * above vn_io_fault_doio() in sys/kern/vfs_vnops.c for details of the issue.
 535  */
 536 static void
 537 prefault_buffer(const char *buf, size_t s)
 538 {
 539         volatile const char *p;
 540         size_t page_size;
 541
 542         if (s == 0)
 543                 return;
 544         page_size = sysconf(_SC_PAGESIZE);
 545         for (p = buf; p < buf + s; p += page_size)
 546                 *p;
 547         /*
 548          * Ensure we touch the last page as well, in case the buffer is not
 549          * page-aligned.
 550          */
 551         *(volatile const char *)(buf + s - 1);
 552 }
 553
 554 /*
 555  * Wrapper for archive_write_data().
 556  */
 557 static void
 558 write_data(struct bsdar *bsdar, struct archive *a, const void *buf, size_t s)
 559 {
 560         ssize_t written;
 561
 562         prefault_buffer(buf, s);
 563         while (s > 0) {
 564                 written = archive_write_data(a, buf, s);
 565                 if (written < 0)
 566                         bsdar_errc(bsdar, archive_errno(a), "%s",
 567                             archive_error_string(a));
 568                 buf = (const char *)buf + written;
 569                 s -= written;
 570         }
 571 }
 572
 573 /*
 574  * Write the resulting archive members.
 575  */
 576 static void
 577 write_objs(struct bsdar *bsdar)
 578 {
 579         struct ar_obj           *obj;
 580         struct archive          *a;
 581         struct archive_entry    *entry;
 582         size_t s_sz;            /* size of archive symbol table. */
 583         size_t pm_sz;           /* size of pseudo members */
 584         size_t w_sz;            /* size of words in symbol table */
 585         size_t                   i;
 586         uint64_t                 nr;
 587         uint32_t                 nr32;
 588
 589         if (elf_version(EV_CURRENT) == EV_NONE)
 590                 bsdar_errc(bsdar, 0, "ELF library initialization failed: %s",
 591                     elf_errmsg(-1));
 592
 593         bsdar->rela_off = 0;
 594
 595         /* Create archive symbol table and archive string table, if need. */
 596         TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 597                 if (!(bsdar->options & AR_SS) && obj->maddr != NULL)
 598                         create_symtab_entry(bsdar, obj->maddr, obj->size);
 599                 if (strlen(obj->name) > _MAXNAMELEN_SVR4)
 600                         add_to_ar_str_table(bsdar, obj->name);
 601                 bsdar->rela_off += _ARHDR_LEN + obj->size + obj->size % 2;
 602         }
 603
 604         /*
 605          * Pad the symbol name string table. It is treated specially because
 606          * symbol name table should be padded by a '\0', not the common '\n'
 607          * for other members. The size of sn table includes the pad bit.
 608          */
 609         if (bsdar->s_cnt != 0 && bsdar->s_sn_sz % 2 != 0)
 610                 bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
 611
 612         /*
 613          * Archive string table is padded by a "\n" as the normal members.
 614          * The difference is that the size of archive string table counts
 615          * in the pad bit, while normal members' size fileds do not.
 616          */
 617         if (bsdar->as != NULL && bsdar->as_sz % 2 != 0)
 618                 bsdar->as[bsdar->as_sz++] = '\n';
 619
 620         /*
 621          * If there is a symbol table, calculate the size of pseudo members,
 622          * convert previously stored relative offsets to absolute ones, and
 623          * then make them Big Endian.
 624          *
 625          * absolute_offset = htobe32(relative_offset + size_of_pseudo_members)
 626          */
 627         w_sz = sizeof(uint32_t);
 628         if (bsdar->s_cnt != 0) {
 629                 s_sz = (bsdar->s_cnt + 1) * sizeof(uint32_t) + bsdar->s_sn_sz;
 630                 pm_sz = _ARMAG_LEN + (_ARHDR_LEN + s_sz);
 631                 if (bsdar->as != NULL)
 632                         pm_sz += _ARHDR_LEN + bsdar->as_sz;
 633                 /* Use the 64-bit word size format if necessary. */
 634                 if (bsdar->s_so_max > UINT32_MAX - pm_sz) {
 635                         w_sz = sizeof(uint64_t);
 636                         pm_sz -= s_sz;
 637                         s_sz = (bsdar->s_cnt + 1) * sizeof(uint64_t) +
 638                             bsdar->s_sn_sz;
 639                         pm_sz += s_sz;
 640                         /* Convert to big-endian. */
 641                         for (i = 0; i < bsdar->s_cnt; i++)
 642                                 bsdar->s_so[i] =
 643                                     htobe64(bsdar->s_so[i] + pm_sz);
 644                 } else {
 645                         /*
 646                          * Convert to big-endian and shuffle in-place to
 647                          * the front of the allocation. XXX UB
 648                          */
 649                         for (i = 0; i < bsdar->s_cnt; i++)
 650                                 ((uint32_t *)(bsdar->s_so))[i] =
 651                                     htobe32(bsdar->s_so[i] + pm_sz);
 652                 }
 653         }
 654
 655         if ((a = archive_write_new()) == NULL)
 656                 bsdar_errc(bsdar, 0, "archive_write_new failed");
 657
 658         archive_write_set_format_ar_svr4(a);
 659
 660         AC(archive_write_open_filename(a, bsdar->filename));
 661
 662         /*
 663          * write the archive symbol table, if there is one.
 664          * If options -s is explicitly specified or we are invoked
 665          * as ranlib, write the symbol table even if it is empty.
 666          */
 667         if ((bsdar->s_cnt != 0 && !(bsdar->options & AR_SS)) ||
 668             bsdar->options & AR_S) {
 669                 entry = archive_entry_new();
 670                 if (entry == NULL)
 671                         bsdar_errc(bsdar, 0, "archive_entry_new failed");
 672                 if (w_sz == sizeof(uint64_t))
 673                         archive_entry_copy_pathname(entry, "/SYM64/");
 674                 else
 675                         archive_entry_copy_pathname(entry, "/");
 676                 if ((bsdar->options & AR_D) == 0)
 677                         archive_entry_set_mtime(entry, time(NULL), 0);
 678                 archive_entry_set_size(entry, (bsdar->s_cnt + 1) * w_sz +
 679                     bsdar->s_sn_sz);
 680                 AC(archive_write_header(a, entry));
 681                 if (w_sz == sizeof(uint64_t)) {
 682                         nr = htobe64(bsdar->s_cnt);
 683                         write_data(bsdar, a, &nr, sizeof(nr));
 684                 } else {
 685                         nr32 = htobe32((uint32_t)bsdar->s_cnt);
 686                         write_data(bsdar, a, &nr32, sizeof(nr32));
 687                 }
 688                 write_data(bsdar, a, bsdar->s_so, w_sz * bsdar->s_cnt);
 689                 write_data(bsdar, a, bsdar->s_sn, bsdar->s_sn_sz);
 690                 archive_entry_free(entry);
 691         }
 692
 693         /* write the archive string table, if any. */
 694         if (bsdar->as != NULL) {
 695                 entry = archive_entry_new();
 696                 if (entry == NULL)
 697                         bsdar_errc(bsdar, 0, "archive_entry_new failed");
 698                 archive_entry_copy_pathname(entry, "//");
 699                 archive_entry_set_size(entry, bsdar->as_sz);
 700                 AC(archive_write_header(a, entry));
 701                 write_data(bsdar, a, bsdar->as, bsdar->as_sz);
 702                 archive_entry_free(entry);
 703         }
 704
 705         /* write normal members. */
 706         TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 707                 entry = archive_entry_new();
 708                 if (entry == NULL)
 709                         bsdar_errc(bsdar, 0, "archive_entry_new failed");
 710                 archive_entry_copy_pathname(entry, obj->name);
 711                 archive_entry_set_uid(entry, obj->uid);
 712                 archive_entry_set_gid(entry, obj->gid);
 713                 archive_entry_set_mode(entry, obj->md);
 714                 archive_entry_set_size(entry, obj->size);
 715                 archive_entry_set_mtime(entry, obj->mtime, 0);
 716                 archive_entry_set_dev(entry, obj->dev);
 717                 archive_entry_set_ino(entry, obj->ino);
 718                 archive_entry_set_filetype(entry, AE_IFREG);
 719                 AC(archive_write_header(a, entry));
 720                 write_data(bsdar, a, obj->maddr, obj->size);
 721                 archive_entry_free(entry);
 722         }
 723
 724         AC(archive_write_close(a));
 725         AC(archive_write_free(a));
 726 }
 727
 728 /*
 729  * Extract global symbols from ELF binary members.
 730  */
 731 static void
 732 create_symtab_entry(struct bsdar *bsdar, void *maddr, size_t size)
 733 {
 734         Elf             *e;
 735         Elf_Scn         *scn;
 736         GElf_Shdr        shdr;
 737         GElf_Sym         sym;
 738         Elf_Data        *data;
 739         char            *name;
 740         size_t           n, shstrndx;
 741         int              elferr, tabndx, len, i;
 742
 743         if ((e = elf_memory(maddr, size)) == NULL) {
 744                 bsdar_warnc(bsdar, 0, "elf_memory() failed: %s",
 745                      elf_errmsg(-1));
 746                 return;
 747         }
 748         if (elf_kind(e) != ELF_K_ELF) {
 749                 /* Silently ignore non-elf member. */
 750                 elf_end(e);
 751                 return;
 752         }
 753         if (elf_getshstrndx(e, &shstrndx) == 0) {
 754                 bsdar_warnc(bsdar, 0, "elf_getshstrndx failed: %s",
 755                      elf_errmsg(-1));
 756                 elf_end(e);
 757                 return;
 758         }
 759
 760         tabndx = -1;
 761         scn = NULL;
 762         while ((scn = elf_nextscn(e, scn)) != NULL) {
 763                 if (gelf_getshdr(scn, &shdr) != &shdr) {
 764                         bsdar_warnc(bsdar, 0,
 765                             "elf_getshdr failed: %s", elf_errmsg(-1));
 766                         continue;
 767                 }
 768                 if ((name = elf_strptr(e, shstrndx, shdr.sh_name)) == NULL) {
 769                         bsdar_warnc(bsdar, 0,
 770                             "elf_strptr failed: %s", elf_errmsg(-1));
 771                         continue;
 772                 }
 773                 if (strcmp(name, ".strtab") == 0) {
 774                         tabndx = elf_ndxscn(scn);
 775                         break;
 776                 }
 777         }
 778         elferr = elf_errno();
 779         if (elferr != 0)
 780                 bsdar_warnc(bsdar, 0, "elf_nextscn failed: %s",
 781                      elf_errmsg(elferr));
 782         if (tabndx == -1) {
 783                 bsdar_warnc(bsdar, 0, "can't find .strtab section");
 784                 elf_end(e);
 785                 return;
 786         }
 787
 788         scn = NULL;
 789         while ((scn = elf_nextscn(e, scn)) != NULL) {
 790                 if (gelf_getshdr(scn, &shdr) != &shdr) {
 791                         bsdar_warnc(bsdar, 0, "elf_getshdr failed: %s",
 792                             elf_errmsg(-1));
 793                         continue;
 794                 }
 795                 if (shdr.sh_type != SHT_SYMTAB)
 796                         continue;
 797
 798                 data = NULL;
 799                 n = 0;
 800                 while (n < shdr.sh_size &&
 801                     (data = elf_getdata(scn, data)) != NULL) {
 802                         len = data->d_size / shdr.sh_entsize;
 803                         for (i = 0; i < len; i++) {
 804                                 if (gelf_getsym(data, i, &sym) != &sym) {
 805                                         bsdar_warnc(bsdar, 0,
 806                                             "gelf_getsym failed: %s",
 807                                              elf_errmsg(-1));
 808                                         continue;
 809                                 }
 810
 811                                 /* keep only global or weak symbols */
 812                                 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL &&
 813                                     GELF_ST_BIND(sym.st_info) != STB_WEAK)
 814                                         continue;
 815
 816                                 /* keep only defined symbols */
 817                                 if (sym.st_shndx == SHN_UNDEF)
 818                                         continue;
 819
 820                                 if ((name = elf_strptr(e, tabndx,
 821                                     sym.st_name)) == NULL) {
 822                                         bsdar_warnc(bsdar, 0,
 823                                             "elf_strptr failed: %s",
 824                                              elf_errmsg(-1));
 825                                         continue;
 826                                 }
 827
 828                                 add_to_ar_sym_table(bsdar, name);
 829                         }
 830                 }
 831         }
 832         elferr = elf_errno();
 833         if (elferr != 0)
 834                 bsdar_warnc(bsdar, 0, "elf_nextscn failed: %s",
 835                      elf_errmsg(elferr));
 836
 837         elf_end(e);
 838 }
 839
 840 /*
 841  * Append to the archive string table buffer.
 842  */
 843 static void
 844 add_to_ar_str_table(struct bsdar *bsdar, const char *name)
 845 {
 846
 847         if (bsdar->as == NULL) {
 848                 bsdar->as_cap = _INIT_AS_CAP;
 849                 bsdar->as_sz = 0;
 850                 if ((bsdar->as = malloc(bsdar->as_cap)) == NULL)
 851                         bsdar_errc(bsdar, errno, "malloc failed");
 852         }
 853
 854         /*
 855          * The space required for holding one member name in as table includes:
 856          * strlen(name) + (1 for '/') + (1 for '\n') + (possibly 1 for padding).
 857          */
 858         while (bsdar->as_sz + strlen(name) + 3 > bsdar->as_cap) {
 859                 bsdar->as_cap *= 2;
 860                 bsdar->as = realloc(bsdar->as, bsdar->as_cap);
 861                 if (bsdar->as == NULL)
 862                         bsdar_errc(bsdar, errno, "realloc failed");
 863         }
 864         strncpy(&bsdar->as[bsdar->as_sz], name, strlen(name));
 865         bsdar->as_sz += strlen(name);
 866         bsdar->as[bsdar->as_sz++] = '/';
 867         bsdar->as[bsdar->as_sz++] = '\n';
 868 }
 869
 870 /*
 871  * Append to the archive symbol table buffer.
 872  */
 873 static void
 874 add_to_ar_sym_table(struct bsdar *bsdar, const char *name)
 875 {
 876
 877         if (bsdar->s_so == NULL) {
 878                 if ((bsdar->s_so = malloc(_INIT_SYMOFF_CAP)) ==
 879                     NULL)
 880                         bsdar_errc(bsdar, errno, "malloc failed");
 881                 bsdar->s_so_cap = _INIT_SYMOFF_CAP;
 882                 bsdar->s_cnt = 0;
 883         }
 884
 885         if (bsdar->s_sn == NULL) {
 886                 if ((bsdar->s_sn = malloc(_INIT_SYMNAME_CAP)) == NULL)
 887                         bsdar_errc(bsdar, errno, "malloc failed");
 888                 bsdar->s_sn_cap = _INIT_SYMNAME_CAP;
 889                 bsdar->s_sn_sz = 0;
 890         }
 891
 892         if (bsdar->s_cnt * sizeof(uint64_t) >= bsdar->s_so_cap) {
 893                 bsdar->s_so_cap *= 2;
 894                 bsdar->s_so = realloc(bsdar->s_so, bsdar->s_so_cap);
 895                 if (bsdar->s_so == NULL)
 896                         bsdar_errc(bsdar, errno, "realloc failed");
 897         }
 898         bsdar->s_so[bsdar->s_cnt] = bsdar->rela_off;
 899         if ((uint64_t)bsdar->rela_off > bsdar->s_so_max)
 900                 bsdar->s_so_max = (uint64_t)bsdar->rela_off;
 901         bsdar->s_cnt++;
 902
 903         /*
 904          * The space required for holding one symbol name in sn table includes:
 905          * strlen(name) + (1 for '\n') + (possibly 1 for padding).
 906          */
 907         while (bsdar->s_sn_sz + strlen(name) + 2 > bsdar->s_sn_cap) {
 908                 bsdar->s_sn_cap *= 2;
 909                 bsdar->s_sn = realloc(bsdar->s_sn, bsdar->s_sn_cap);
 910                 if (bsdar->s_sn == NULL)
 911                         bsdar_errc(bsdar, errno, "realloc failed");
 912         }
 913         strncpy(&bsdar->s_sn[bsdar->s_sn_sz], name, strlen(name));
 914         bsdar->s_sn_sz += strlen(name);
 915         bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
 916 }