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  *    in this position and unchanged.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 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 <errno.h>
  39 #include <fcntl.h>
  40 #include <gelf.h>
  41 #include <libgen.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45 #include <sysexits.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(uint32_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_archive(struct bsdar *bsdar, char mode);
  71 static void     write_cleanup(struct bsdar *bsdar);
  72 static void     write_data(struct bsdar *bsdar, struct archive *a,
  73                     const void *buf, size_t s);
  74 static void     write_objs(struct bsdar *bsdar);
  75
  76 void
  77 ar_mode_d(struct bsdar *bsdar)
  78 {
  79
  80         write_archive(bsdar, 'd');
  81 }
  82
  83 void
  84 ar_mode_m(struct bsdar *bsdar)
  85 {
  86
  87         write_archive(bsdar, 'm');
  88 }
  89
  90 void
  91 ar_mode_q(struct bsdar *bsdar)
  92 {
  93
  94         write_archive(bsdar, 'q');
  95 }
  96
  97 void
  98 ar_mode_r(struct bsdar *bsdar)
  99 {
 100
 101         write_archive(bsdar, 'r');
 102 }
 103
 104 void
 105 ar_mode_s(struct bsdar *bsdar)
 106 {
 107
 108         write_archive(bsdar, 's');
 109 }
 110
 111 void
 112 ar_mode_A(struct bsdar *bsdar)
 113 {
 114
 115         write_archive(bsdar, 'A');
 116 }
 117
 118 /*
 119  * Create object from file, return created obj upon success, or NULL
 120  * when an error occurs or the member is not newer than existing
 121  * one while -u is specified.
 122  */
 123 static struct ar_obj *
 124 create_obj_from_file(struct bsdar *bsdar, const char *name, time_t mtime)
 125 {
 126         struct ar_obj           *obj;
 127         struct stat              sb;
 128         const char              *bname;
 129         char                    *tmpname;
 130
 131         if (name == NULL)
 132                 return (NULL);
 133
 134         obj = malloc(sizeof(struct ar_obj));
 135         if (obj == NULL)
 136                 bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 137         if ((obj->fd = open(name, O_RDONLY, 0)) < 0) {
 138                 bsdar_warnc(bsdar, errno, "can't open file: %s", name);
 139                 free(obj);
 140                 return (NULL);
 141         }
 142
 143         tmpname = strdup(name);
 144         if (tmpname == NULL)
 145                 bsdar_errc(bsdar, EX_SOFTWARE, errno, "strdup failed");
 146         if ((bname = basename(tmpname)) == NULL)
 147                 bsdar_errc(bsdar, EX_SOFTWARE, errno, "basename failed");
 148         if (bsdar->options & AR_TR && strlen(bname) > _TRUNCATE_LEN) {
 149                 if ((obj->name = malloc(_TRUNCATE_LEN + 1)) == NULL)
 150                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 151                 (void)strncpy(obj->name, bname, _TRUNCATE_LEN);
 152                 obj->name[_TRUNCATE_LEN] = '\0';
 153         } else
 154                 if ((obj->name = strdup(bname)) == NULL)
 155                     bsdar_errc(bsdar, EX_SOFTWARE, errno, "strdup failed");
 156         free(tmpname);
 157
 158         if (fstat(obj->fd, &sb) < 0) {
 159                 bsdar_warnc(bsdar, errno, "can't fstat file: %s", obj->name);
 160                 goto giveup;
 161         }
 162         if (!S_ISREG(sb.st_mode)) {
 163                 bsdar_warnc(bsdar, 0, "%s is not an ordinary file", obj->name);
 164                 goto giveup;
 165         }
 166
 167         /*
 168          * When option '-u' is specified and member is not newer than the
 169          * existing one, the replace will not happen. While if mtime == 0,
 170          * which indicates that this is to "replace a none exist member",
 171          * the replace will proceed regardless of '-u'.
 172          */
 173         if (mtime != 0 && bsdar->options & AR_U && sb.st_mtime <= mtime)
 174                 goto giveup;
 175
 176         /*
 177          * When option '-D' is specified, mtime and UID / GID from the file
 178          * will be replaced with 0, and file mode with 644. This ensures that
 179          * checksums will match for two archives containing the exact same
 180          * files.
 181          */
 182         if (bsdar->options & AR_D) {
 183                 obj->uid = 0;
 184                 obj->gid = 0;
 185                 obj->mtime = 0;
 186                 obj->md = S_IFREG | 0644;
 187         } else {
 188                 obj->uid = sb.st_uid;
 189                 obj->gid = sb.st_gid;
 190                 obj->mtime = sb.st_mtime;
 191                 obj->md = sb.st_mode;
 192         }
 193         obj->size = sb.st_size;
 194         obj->dev = sb.st_dev;
 195         obj->ino = sb.st_ino;
 196
 197         if (obj->size == 0) {
 198                 obj->maddr = NULL;
 199                 return (obj);
 200         }
 201
 202         if ((obj->maddr = mmap(NULL, obj->size, PROT_READ,
 203             MAP_PRIVATE, obj->fd, (off_t)0)) == MAP_FAILED) {
 204                 bsdar_warnc(bsdar, errno, "can't mmap file: %s", obj->name);
 205                 goto giveup;
 206         }
 207         if (close(obj->fd) < 0)
 208                 bsdar_errc(bsdar, EX_SOFTWARE, errno, "close failed: %s",
 209                     obj->name);
 210
 211         return (obj);
 212
 213 giveup:
 214         if (close(obj->fd) < 0)
 215                 bsdar_errc(bsdar, EX_SOFTWARE, errno, "close failed: %s",
 216                     obj->name);
 217         free(obj->name);
 218         free(obj);
 219         return (NULL);
 220 }
 221
 222 /*
 223  * Free object itself and its associated allocations.
 224  */
 225 static void
 226 free_obj(struct bsdar *bsdar, struct ar_obj *obj)
 227 {
 228         if (obj->fd == -1)
 229                 free(obj->maddr);
 230         else
 231                 if (obj->maddr != NULL && munmap(obj->maddr, obj->size))
 232                         bsdar_warnc(bsdar, errno,
 233                             "can't munmap file: %s", obj->name);
 234         free(obj->name);
 235         free(obj);
 236 }
 237
 238 /*
 239  * Insert obj to the tail, or before/after the pos obj.
 240  */
 241 static void
 242 insert_obj(struct bsdar *bsdar, struct ar_obj *obj, struct ar_obj *pos)
 243 {
 244         if (obj == NULL)
 245                 bsdar_errc(bsdar, EX_SOFTWARE, 0, "try to insert a null obj");
 246
 247         if (pos == NULL || obj == pos)
 248                 /*
 249                  * If the object to move happens to be the position obj,
 250                  * or if there is not a pos obj, move it to tail.
 251                  */
 252                 goto tail;
 253
 254         if (bsdar->options & AR_B) {
 255                 TAILQ_INSERT_BEFORE(pos, obj, objs);
 256                 return;
 257         }
 258         if (bsdar->options & AR_A) {
 259                 TAILQ_INSERT_AFTER(&bsdar->v_obj, pos, obj, objs);
 260                 return;
 261         }
 262
 263 tail:
 264         TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
 265
 266 }
 267
 268 /*
 269  * Read objects from archive into v_obj list. Note that checkargv is
 270  * set when read_objs is used to read objects from the target of
 271  * ADDLIB command (ar script mode), in this case argv array possibly
 272  * specifies the members ADDLIB want.
 273  */
 274 static void
 275 read_objs(struct bsdar *bsdar, const char *archive, int checkargv)
 276 {
 277         struct archive           *a;
 278         struct archive_entry     *entry;
 279         struct ar_obj            *obj;
 280         const char               *name;
 281         const char               *bname;
 282         char                     *buff;
 283         char                    **av;
 284         size_t                    size;
 285         int                       i, r, find;
 286
 287         if ((a = archive_read_new()) == NULL)
 288                 bsdar_errc(bsdar, EX_SOFTWARE, 0, "archive_read_new failed");
 289         archive_read_support_format_ar(a);
 290         AC(archive_read_open_filename(a, archive, DEF_BLKSZ));
 291         for (;;) {
 292                 r = archive_read_next_header(a, &entry);
 293                 if (r == ARCHIVE_FATAL)
 294                         bsdar_errc(bsdar, EX_DATAERR, archive_errno(a), "%s",
 295                             archive_error_string(a));
 296                 if (r == ARCHIVE_EOF)
 297                         break;
 298                 if (r == ARCHIVE_WARN || r == ARCHIVE_RETRY)
 299                         bsdar_warnc(bsdar, archive_errno(a), "%s",
 300                             archive_error_string(a));
 301                 if (r == ARCHIVE_RETRY) {
 302                         bsdar_warnc(bsdar, 0, "Retrying...");
 303                         continue;
 304                 }
 305
 306                 name = archive_entry_pathname(entry);
 307
 308                 /*
 309                  * skip pseudo members.
 310                  */
 311                 if (strcmp(name, "/") == 0 || strcmp(name, "//") == 0)
 312                         continue;
 313
 314                 /*
 315                  * If checkargv is set, only read those members specified
 316                  * in argv.
 317                  */
 318                 if (checkargv && bsdar->argc > 0) {
 319                         find = 0;
 320                         for(i = 0; i < bsdar->argc; i++) {
 321                                 av = &bsdar->argv[i];
 322                                 if (*av == NULL)
 323                                         continue;
 324                                 if ((bname = basename(*av)) == NULL)
 325                                         bsdar_errc(bsdar, EX_SOFTWARE, errno,
 326                                             "basename failed");
 327                                 if (strcmp(bname, name) != 0)
 328                                         continue;
 329
 330                                 *av = NULL;
 331                                 find = 1;
 332                                 break;
 333                         }
 334                         if (!find)
 335                                 continue;
 336                 }
 337
 338                 size = archive_entry_size(entry);
 339
 340                 if (size > 0) {
 341                         if ((buff = malloc(size)) == NULL)
 342                                 bsdar_errc(bsdar, EX_SOFTWARE, errno,
 343                                     "malloc failed");
 344                         if (archive_read_data(a, buff, size) != (ssize_t)size) {
 345                                 bsdar_warnc(bsdar, archive_errno(a), "%s",
 346                                     archive_error_string(a));
 347                                 free(buff);
 348                                 continue;
 349                         }
 350                 } else
 351                         buff = NULL;
 352
 353                 obj = malloc(sizeof(struct ar_obj));
 354                 if (obj == NULL)
 355                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 356                 obj->maddr = buff;
 357                 if ((obj->name = strdup(name)) == NULL)
 358                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "strdup failed");
 359                 obj->size = size;
 360                 obj->uid = archive_entry_uid(entry);
 361                 obj->gid = archive_entry_gid(entry);
 362                 obj->md = archive_entry_mode(entry);
 363                 obj->mtime = archive_entry_mtime(entry);
 364                 obj->dev = 0;
 365                 obj->ino = 0;
 366
 367                 /*
 368                  * Objects from archive have obj->fd set to -1,
 369                  * for the ease of cleaning up.
 370                  */
 371                 obj->fd = -1;
 372                 TAILQ_INSERT_TAIL(&bsdar->v_obj, obj, objs);
 373         }
 374         AC(archive_read_close(a));
 375         AC(archive_read_free(a));
 376 }
 377
 378 /*
 379  * Determine the constitution of resulting archive.
 380  */
 381 static void
 382 write_archive(struct bsdar *bsdar, char mode)
 383 {
 384         struct ar_obj            *nobj, *obj, *obj_temp, *pos;
 385         struct stat               sb;
 386         const char               *bname;
 387         char                    **av;
 388         int                       i;
 389
 390         TAILQ_INIT(&bsdar->v_obj);
 391         nobj = NULL;
 392         pos = NULL;
 393         memset(&sb, 0, sizeof(sb));
 394
 395         /*
 396          * Test if the specified archive exists, to figure out
 397          * whether we are creating one here.
 398          */
 399         if (stat(bsdar->filename, &sb) != 0) {
 400                 if (errno != ENOENT) {
 401                         bsdar_warnc(bsdar, 0, "stat %s failed",
 402                             bsdar->filename);
 403                         return;
 404                 }
 405
 406                 /* We do not create archive in mode 'd', 'm' and 's'.  */
 407                 if (mode != 'r' && mode != 'q') {
 408                         bsdar_warnc(bsdar, 0, "%s: no such file",
 409                             bsdar->filename);
 410                         return;
 411                 }
 412
 413                 /* Issue a warning if -c is not specified when creating. */
 414                 if (!(bsdar->options & AR_C))
 415                         bsdar_warnc(bsdar, 0, "creating %s", bsdar->filename);
 416                 goto new_archive;
 417         }
 418
 419         /*
 420          * First read members from existing archive.
 421          */
 422         read_objs(bsdar, bsdar->filename, 0);
 423
 424         /*
 425          * For mode 's', no member will be moved, deleted or replaced.
 426          */
 427         if (mode == 's')
 428                 goto write_objs;
 429
 430         /*
 431          * For mode 'q', we don't need to adjust existing members either.
 432          * Also, -a, -b and -i are ignored in this mode. New members are
 433          * always inserted at tail.
 434          */
 435         if (mode == 'q')
 436                 goto new_archive;
 437
 438         /*
 439          * Mode 'A' adds the contents of another archive to the tail of
 440          * current archive. Note that mode 'A' is a special mode for the
 441          * ADDLIB command of the ar script mode. Currently there is no
 442          * access to this function from the ar command line mode.
 443          */
 444         if (mode == 'A') {
 445                 /*
 446                  * Read objects from the target archive of ADDLIB command.
 447                  * If there are members specified in argv, read those members
 448                  * only, otherwise the entire archive will be read.
 449                  */
 450                 read_objs(bsdar, bsdar->addlib, 1);
 451                 goto write_objs;
 452         }
 453
 454         /*
 455          * Try to find the position member specified by user.
 456          */
 457         if (bsdar->options & AR_A || bsdar->options & AR_B) {
 458                 TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 459                         if (strcmp(obj->name, bsdar->posarg) == 0) {
 460                                 pos = obj;
 461                                 break;
 462                         }
 463                 }
 464
 465                 /*
 466                  * If can't find `pos' specified by user,
 467                  * silently insert objects at tail.
 468                  */
 469                 if (pos == NULL)
 470                         bsdar->options &= ~(AR_A | AR_B);
 471         }
 472
 473         for (i = 0; i < bsdar->argc; i++) {
 474                 av = &bsdar->argv[i];
 475
 476                 TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
 477                         if ((bname = basename(*av)) == NULL)
 478                                 bsdar_errc(bsdar, EX_SOFTWARE, errno,
 479                                     "basename failed");
 480                         if (bsdar->options & AR_TR) {
 481                                 if (strncmp(bname, obj->name, _TRUNCATE_LEN))
 482                                         continue;
 483                         } else
 484                                 if (strcmp(bname, obj->name) != 0)
 485                                         continue;
 486
 487                         if (mode == 'r') {
 488                                 /*
 489                                  * if the new member is not qualified
 490                                  * to replace the old one, skip it.
 491                                  */
 492                                 nobj = create_obj_from_file(bsdar, *av,
 493                                     obj->mtime);
 494                                 if (nobj == NULL)
 495                                         goto skip_obj;
 496                         }
 497
 498                         if (bsdar->options & AR_V)
 499                                 (void)fprintf(stdout, "%c - %s\n", mode,
 500                                     *av);
 501
 502                         TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
 503                         if (mode == 'd' || mode == 'r')
 504                                 free_obj(bsdar, obj);
 505
 506                         if (mode == 'm')
 507                                 insert_obj(bsdar, obj, pos);
 508                         if (mode == 'r')
 509                                 insert_obj(bsdar, nobj, pos);
 510
 511                 skip_obj:
 512                         *av = NULL;
 513                         break;
 514                 }
 515
 516         }
 517
 518 new_archive:
 519         /*
 520          * When operating in mode 'r', directly add those user specified
 521          * objects which do not exist in current archive. When operating
 522          * in mode 'q', all objects specified in command line args are
 523          * appended to the archive, without comparing with existing ones.
 524          */
 525         for (i = 0; i < bsdar->argc; i++) {
 526                 av = &bsdar->argv[i];
 527                 if (*av != NULL && (mode == 'r' || mode == 'q')) {
 528                         nobj = create_obj_from_file(bsdar, *av, 0);
 529                         if (nobj != NULL)
 530                                 insert_obj(bsdar, nobj, pos);
 531                         if (bsdar->options & AR_V && nobj != NULL)
 532                                 (void)fprintf(stdout, "a - %s\n", *av);
 533                         *av = NULL;
 534                 }
 535         }
 536
 537 write_objs:
 538         write_objs(bsdar);
 539         write_cleanup(bsdar);
 540 }
 541
 542 /*
 543  * Memory cleaning up.
 544  */
 545 static void
 546 write_cleanup(struct bsdar *bsdar)
 547 {
 548         struct ar_obj           *obj, *obj_temp;
 549
 550         TAILQ_FOREACH_SAFE(obj, &bsdar->v_obj, objs, obj_temp) {
 551                 TAILQ_REMOVE(&bsdar->v_obj, obj, objs);
 552                 free_obj(bsdar, obj);
 553         }
 554
 555         free(bsdar->as);
 556         free(bsdar->s_so);
 557         free(bsdar->s_sn);
 558         bsdar->as = NULL;
 559         bsdar->s_so = NULL;
 560         bsdar->s_sn = NULL;
 561 }
 562
 563 /*
 564  * Fault in the buffer prior to writing as a workaround for poor performance
 565  * due to interaction with kernel fs deadlock avoidance code. See the comment
 566  * above vn_io_fault_doio() in sys/kern/vfs_vnops.c for details of the issue.
 567  */
 568 static void
 569 prefault_buffer(const char *buf, size_t s)
 570 {
 571         volatile const char *p;
 572         size_t page_size;
 573
 574         if (s == 0)
 575                 return;
 576         page_size = sysconf(_SC_PAGESIZE);
 577         for (p = buf; p < buf + s; p += page_size)
 578                 *p;
 579         /*
 580          * Ensure we touch the last page as well, in case the buffer is not
 581          * page-aligned.
 582          */
 583         *(volatile const char *)(buf + s - 1);
 584 }
 585
 586 /*
 587  * Wrapper for archive_write_data().
 588  */
 589 static void
 590 write_data(struct bsdar *bsdar, struct archive *a, const void *buf, size_t s)
 591 {
 592         ssize_t written;
 593
 594         prefault_buffer(buf, s);
 595         while (s > 0) {
 596                 written = archive_write_data(a, buf, s);
 597                 if (written < 0)
 598                         bsdar_errc(bsdar, EX_SOFTWARE, archive_errno(a), "%s",
 599                             archive_error_string(a));
 600                 buf = (const char *)buf + written;
 601                 s -= written;
 602         }
 603 }
 604
 605 /*
 606  * Write the resulting archive members.
 607  */
 608 static void
 609 write_objs(struct bsdar *bsdar)
 610 {
 611         struct ar_obj           *obj;
 612         struct archive          *a;
 613         struct archive_entry    *entry;
 614         size_t s_sz;            /* size of archive symbol table. */
 615         size_t pm_sz;           /* size of pseudo members */
 616         int                      i, nr;
 617
 618         if (elf_version(EV_CURRENT) == EV_NONE)
 619                 bsdar_errc(bsdar, EX_SOFTWARE, 0,
 620                     "ELF library initialization failed: %s", elf_errmsg(-1));
 621
 622         bsdar->rela_off = 0;
 623
 624         /* Create archive symbol table and archive string table, if need. */
 625         TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 626                 if (!(bsdar->options & AR_SS) && obj->maddr != NULL)
 627                         create_symtab_entry(bsdar, obj->maddr, obj->size);
 628                 if (strlen(obj->name) > _MAXNAMELEN_SVR4)
 629                         add_to_ar_str_table(bsdar, obj->name);
 630                 bsdar->rela_off += _ARHDR_LEN + obj->size + obj->size % 2;
 631                 if (bsdar->rela_off > UINT32_MAX)
 632                         bsdar_errc(bsdar, EX_SOFTWARE, 0,
 633                             "Symbol table offset overflow");
 634         }
 635
 636         /*
 637          * Pad the symbol name string table. It is treated specially because
 638          * symbol name table should be padded by a '\0', not the common '\n'
 639          * for other members. The size of sn table includes the pad bit.
 640          */
 641         if (bsdar->s_cnt != 0 && bsdar->s_sn_sz % 2 != 0)
 642                 bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
 643
 644         /*
 645          * Archive string table is padded by a "\n" as the normal members.
 646          * The difference is that the size of archive string table counts
 647          * in the pad bit, while normal members' size fileds do not.
 648          */
 649         if (bsdar->as != NULL && bsdar->as_sz % 2 != 0)
 650                 bsdar->as[bsdar->as_sz++] = '\n';
 651
 652         /*
 653          * If there is a symbol table, calculate the size of pseudo members,
 654          * convert previously stored relative offsets to absolute ones, and
 655          * then make them Big Endian.
 656          *
 657          * absolute_offset = htobe32(relative_offset + size_of_pseudo_members)
 658          */
 659
 660         if (bsdar->s_cnt != 0) {
 661                 s_sz = (bsdar->s_cnt + 1) * sizeof(uint32_t) + bsdar->s_sn_sz;
 662                 pm_sz = _ARMAG_LEN + (_ARHDR_LEN + s_sz);
 663                 if (bsdar->as != NULL)
 664                         pm_sz += _ARHDR_LEN + bsdar->as_sz;
 665                 for (i = 0; (size_t)i < bsdar->s_cnt; i++) {
 666                         if (*(bsdar->s_so + i) > UINT32_MAX - pm_sz)
 667                                 bsdar_errc(bsdar, EX_SOFTWARE, 0,
 668                                     "Symbol table offset overflow");
 669                         *(bsdar->s_so + i) = htobe32(*(bsdar->s_so + i) +
 670                             pm_sz);
 671                 }
 672         }
 673
 674         if ((a = archive_write_new()) == NULL)
 675                 bsdar_errc(bsdar, EX_SOFTWARE, 0, "archive_write_new failed");
 676
 677         archive_write_set_format_ar_svr4(a);
 678
 679         AC(archive_write_open_filename(a, bsdar->filename));
 680
 681         /*
 682          * write the archive symbol table, if there is one.
 683          * If options -s is explicitly specified or we are invoked
 684          * as ranlib, write the symbol table even if it is empty.
 685          */
 686         if ((bsdar->s_cnt != 0 && !(bsdar->options & AR_SS)) ||
 687             bsdar->options & AR_S) {
 688                 entry = archive_entry_new();
 689                 if (entry == NULL)
 690                         bsdar_errc(bsdar, EX_SOFTWARE, 0,
 691                             "archive_entry_new failed");
 692                 archive_entry_copy_pathname(entry, "/");
 693                 if ((bsdar->options & AR_D) == 0)
 694                         archive_entry_set_mtime(entry, time(NULL), 0);
 695                 archive_entry_set_size(entry, (bsdar->s_cnt + 1) *
 696                     sizeof(uint32_t) + bsdar->s_sn_sz);
 697                 AC(archive_write_header(a, entry));
 698                 nr = htobe32(bsdar->s_cnt);
 699                 write_data(bsdar, a, &nr, sizeof(uint32_t));
 700                 write_data(bsdar, a, bsdar->s_so, sizeof(uint32_t) *
 701                     bsdar->s_cnt);
 702                 write_data(bsdar, a, bsdar->s_sn, bsdar->s_sn_sz);
 703                 archive_entry_free(entry);
 704         }
 705
 706         /* write the archive string table, if any. */
 707         if (bsdar->as != NULL) {
 708                 entry = archive_entry_new();
 709                 if (entry == NULL)
 710                         bsdar_errc(bsdar, EX_SOFTWARE, 0,
 711                             "archive_entry_new failed");
 712                 archive_entry_copy_pathname(entry, "//");
 713                 archive_entry_set_size(entry, bsdar->as_sz);
 714                 AC(archive_write_header(a, entry));
 715                 write_data(bsdar, a, bsdar->as, bsdar->as_sz);
 716                 archive_entry_free(entry);
 717         }
 718
 719         /* write normal members. */
 720         TAILQ_FOREACH(obj, &bsdar->v_obj, objs) {
 721                 entry = archive_entry_new();
 722                 if (entry == NULL)
 723                         bsdar_errc(bsdar, EX_SOFTWARE, 0,
 724                             "archive_entry_new failed");
 725                 archive_entry_copy_pathname(entry, obj->name);
 726                 archive_entry_set_uid(entry, obj->uid);
 727                 archive_entry_set_gid(entry, obj->gid);
 728                 archive_entry_set_mode(entry, obj->md);
 729                 archive_entry_set_size(entry, obj->size);
 730                 archive_entry_set_mtime(entry, obj->mtime, 0);
 731                 archive_entry_set_dev(entry, obj->dev);
 732                 archive_entry_set_ino(entry, obj->ino);
 733                 archive_entry_set_filetype(entry, AE_IFREG);
 734                 AC(archive_write_header(a, entry));
 735                 write_data(bsdar, a, obj->maddr, obj->size);
 736                 archive_entry_free(entry);
 737         }
 738
 739         AC(archive_write_close(a));
 740         AC(archive_write_free(a));
 741 }
 742
 743 /*
 744  * Extract global symbols from ELF binary members.
 745  */
 746 static void
 747 create_symtab_entry(struct bsdar *bsdar, void *maddr, size_t size)
 748 {
 749         Elf             *e;
 750         Elf_Scn         *scn;
 751         GElf_Shdr        shdr;
 752         GElf_Sym         sym;
 753         Elf_Data        *data;
 754         char            *name;
 755         size_t           n, shstrndx;
 756         int              elferr, tabndx, len, i;
 757
 758         if ((e = elf_memory(maddr, size)) == NULL) {
 759                 bsdar_warnc(bsdar, 0, "elf_memory() failed: %s",
 760                      elf_errmsg(-1));
 761                 return;
 762         }
 763         if (elf_kind(e) != ELF_K_ELF) {
 764                 /* Silently ignore non-elf member. */
 765                 elf_end(e);
 766                 return;
 767         }
 768         if (elf_getshstrndx(e, &shstrndx) == 0) {
 769                 bsdar_warnc(bsdar, EX_SOFTWARE, 0, "elf_getshstrndx failed: %s",
 770                      elf_errmsg(-1));
 771                 elf_end(e);
 772                 return;
 773         }
 774
 775         tabndx = -1;
 776         scn = NULL;
 777         while ((scn = elf_nextscn(e, scn)) != NULL) {
 778                 if (gelf_getshdr(scn, &shdr) != &shdr) {
 779                         bsdar_warnc(bsdar, 0,
 780                             "elf_getshdr failed: %s", elf_errmsg(-1));
 781                         continue;
 782                 }
 783                 if ((name = elf_strptr(e, shstrndx, shdr.sh_name)) == NULL) {
 784                         bsdar_warnc(bsdar, 0,
 785                             "elf_strptr failed: %s", elf_errmsg(-1));
 786                         continue;
 787                 }
 788                 if (strcmp(name, ".strtab") == 0) {
 789                         tabndx = elf_ndxscn(scn);
 790                         break;
 791                 }
 792         }
 793         elferr = elf_errno();
 794         if (elferr != 0)
 795                 bsdar_warnc(bsdar, 0, "elf_nextscn failed: %s",
 796                      elf_errmsg(elferr));
 797         if (tabndx == -1) {
 798                 bsdar_warnc(bsdar, 0, "can't find .strtab section");
 799                 elf_end(e);
 800                 return;
 801         }
 802
 803         scn = NULL;
 804         while ((scn = elf_nextscn(e, scn)) != NULL) {
 805                 if (gelf_getshdr(scn, &shdr) != &shdr) {
 806                         bsdar_warnc(bsdar, EX_SOFTWARE, 0,
 807                             "elf_getshdr failed: %s", elf_errmsg(-1));
 808                         continue;
 809                 }
 810                 if (shdr.sh_type != SHT_SYMTAB)
 811                         continue;
 812
 813                 data = NULL;
 814                 n = 0;
 815                 while (n < shdr.sh_size &&
 816                     (data = elf_getdata(scn, data)) != NULL) {
 817                         len = data->d_size / shdr.sh_entsize;
 818                         for (i = 0; i < len; i++) {
 819                                 if (gelf_getsym(data, i, &sym) != &sym) {
 820                                         bsdar_warnc(bsdar, EX_SOFTWARE, 0,
 821                                             "gelf_getsym failed: %s",
 822                                              elf_errmsg(-1));
 823                                         continue;
 824                                 }
 825
 826                                 /* keep only global or weak symbols */
 827                                 if (GELF_ST_BIND(sym.st_info) != STB_GLOBAL &&
 828                                     GELF_ST_BIND(sym.st_info) != STB_WEAK)
 829                                         continue;
 830
 831                                 /* keep only defined symbols */
 832                                 if (sym.st_shndx == SHN_UNDEF)
 833                                         continue;
 834
 835                                 if ((name = elf_strptr(e, tabndx,
 836                                     sym.st_name)) == NULL) {
 837                                         bsdar_warnc(bsdar, EX_SOFTWARE, 0,
 838                                             "elf_strptr failed: %s",
 839                                              elf_errmsg(-1));
 840                                         continue;
 841                                 }
 842
 843                                 add_to_ar_sym_table(bsdar, name);
 844                         }
 845                 }
 846         }
 847         elferr = elf_errno();
 848         if (elferr != 0)
 849                 bsdar_warnc(bsdar, EX_SOFTWARE, 0, "elf_nextscn failed: %s",
 850                      elf_errmsg(elferr));
 851
 852         elf_end(e);
 853 }
 854
 855 /*
 856  * Append to the archive string table buffer.
 857  */
 858 static void
 859 add_to_ar_str_table(struct bsdar *bsdar, const char *name)
 860 {
 861
 862         if (bsdar->as == NULL) {
 863                 bsdar->as_cap = _INIT_AS_CAP;
 864                 bsdar->as_sz = 0;
 865                 if ((bsdar->as = malloc(bsdar->as_cap)) == NULL)
 866                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 867         }
 868
 869         /*
 870          * The space required for holding one member name in as table includes:
 871          * strlen(name) + (1 for '/') + (1 for '\n') + (possibly 1 for padding).
 872          */
 873         while (bsdar->as_sz + strlen(name) + 3 > bsdar->as_cap) {
 874                 bsdar->as_cap *= 2;
 875                 bsdar->as = realloc(bsdar->as, bsdar->as_cap);
 876                 if (bsdar->as == NULL)
 877                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
 878         }
 879         strncpy(&bsdar->as[bsdar->as_sz], name, strlen(name));
 880         bsdar->as_sz += strlen(name);
 881         bsdar->as[bsdar->as_sz++] = '/';
 882         bsdar->as[bsdar->as_sz++] = '\n';
 883 }
 884
 885 /*
 886  * Append to the archive symbol table buffer.
 887  */
 888 static void
 889 add_to_ar_sym_table(struct bsdar *bsdar, const char *name)
 890 {
 891
 892         if (bsdar->s_so == NULL) {
 893                 if ((bsdar->s_so = malloc(_INIT_SYMOFF_CAP)) ==
 894                     NULL)
 895                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 896                 bsdar->s_so_cap = _INIT_SYMOFF_CAP;
 897                 bsdar->s_cnt = 0;
 898         }
 899
 900         if (bsdar->s_sn == NULL) {
 901                 if ((bsdar->s_sn = malloc(_INIT_SYMNAME_CAP)) == NULL)
 902                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "malloc failed");
 903                 bsdar->s_sn_cap = _INIT_SYMNAME_CAP;
 904                 bsdar->s_sn_sz = 0;
 905         }
 906
 907         if (bsdar->s_cnt * sizeof(uint32_t) >= bsdar->s_so_cap) {
 908                 bsdar->s_so_cap *= 2;
 909                 bsdar->s_so = realloc(bsdar->s_so, bsdar->s_so_cap);
 910                 if (bsdar->s_so == NULL)
 911                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
 912         }
 913         bsdar->s_so[bsdar->s_cnt] = bsdar->rela_off;
 914         bsdar->s_cnt++;
 915
 916         /*
 917          * The space required for holding one symbol name in sn table includes:
 918          * strlen(name) + (1 for '\n') + (possibly 1 for padding).
 919          */
 920         while (bsdar->s_sn_sz + strlen(name) + 2 > bsdar->s_sn_cap) {
 921                 bsdar->s_sn_cap *= 2;
 922                 bsdar->s_sn = realloc(bsdar->s_sn, bsdar->s_sn_cap);
 923                 if (bsdar->s_sn == NULL)
 924                         bsdar_errc(bsdar, EX_SOFTWARE, errno, "realloc failed");
 925         }
 926         strncpy(&bsdar->s_sn[bsdar->s_sn_sz], name, strlen(name));
 927         bsdar->s_sn_sz += strlen(name);
 928         bsdar->s_sn[bsdar->s_sn_sz++] = '\0';
 929 }