usr/src/cmd/sgs/libelf/common/ar.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 1990, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 /*
  27  *      Copyright (c) 1988 AT&T
  28  *        All Rights Reserved
  29  */
  30
  31 #include <ar.h>
  32 #include <stdlib.h>
  33 #include <memory.h>
  34 #include <errno.h>
  35 #include <libelf.h>
  36 #include "decl.h"
  37 #include "msg.h"
  38 #include "member.h"
  39
  40 #define MANGLE  '\177'
  41
  42
  43 /*
  44  * Archive processing
  45  *      When processing an archive member, two things can happen
  46  *      that are a little tricky.
  47  *
  48  * Sliding
  49  *      Sliding support is left in for backward compatibility and for
  50  *      support of Archives produced on other systems.  The bundled
  51  *      ar(1) produces archives with all members on a 4 byte boundry,
  52  *      so current archives should need no sliding.
  53  *
  54  *      Archive members that are only 2-byte aligned within the file will
  55  *      be slid.  To reuse the file's memory image, the library slides an
  56  *      archive member into its header to align the bytes.  This means
  57  *      the header must be disposable.
  58  *
  59  * Header reuse
  60  *      Because the library can trample the header, it must be preserved to
  61  *      avoid restrictions on archive member reuse.  That is, if the member
  62  *      header changes, the library may see garbage the next time it looks
  63  *      at the header.  After extracting the original header, the library
  64  *      appends it to the parents `ed_memlist' list, thus future lookups first
  65  *      check this list to determine if a member has previously been processed
  66  *      and whether sliding occured.
  67  */
  68
  69
  70 /*
  71  * Size check
  72  *      If the header is too small, the following generates a negative
  73  *      subscript for x.x and fails to compile.
  74  *
  75  * The check is based on sizeof (Elf64) because that's always going
  76  * to be at least as big as Elf32.
  77  */
  78
  79 struct  x
  80 {
  81         char    x[sizeof (struct ar_hdr) - 3 * sizeof (Elf64) - 1];
  82 };
  83
  84
  85
  86 static const char       fmag[] = ARFMAG;
  87
  88
  89 /*
  90  * Convert a string starting at 'p' and ending at 'end' into
  91  * an integer.  Base is the base of the number being converted
  92  * (either 8 or 10).
  93  *
  94  * Returns the converted integer of the string being scaned.
  95  */
  96 unsigned long
  97 _elf_number(char *p, char *end, int base)
  98 {
  99         register unsigned       c;
 100         register unsigned long  n = 0;
 101
 102         while (p < end) {
 103                 if ((c = *p - '0') >= base) {
 104                         while (*p++ == ' ')
 105                                 if (p >= end)
 106                                         return (n);
 107                         return (0);
 108                 }
 109                 n *= base;
 110                 n += c;
 111                 ++p;
 112         }
 113         return (n);
 114 }
 115
 116
 117 /*
 118  * Convert ar_hdr to Member
 119  *      Converts ascii file representation to the binary memory values.
 120  */
 121 Member *
 122 _elf_armem(Elf *elf, char *file, size_t fsz)
 123 {
 124         register struct ar_hdr  *f = (struct ar_hdr *)file;
 125         register Member         *m;
 126         register Memlist        *l, * ol;
 127         register Memident       *i;
 128
 129         if (fsz < sizeof (struct ar_hdr)) {
 130                 _elf_seterr(EFMT_ARHDRSZ, 0);
 131                 return (0);
 132         }
 133
 134         /*
 135          * Determine in this member has already been processed
 136          */
 137         for (l = elf->ed_memlist, ol = l; l; ol = l, l = l->m_next)
 138                 for (i = (Memident *)(l + 1); i < l->m_free; i++)
 139                         if (i->m_offset == file)
 140                                 return (i->m_member);
 141
 142         if (f->ar_fmag[0] != fmag[0] || f->ar_fmag[1] != fmag[1]) {
 143                 _elf_seterr(EFMT_ARFMAG, 0);
 144                 return (0);
 145         }
 146
 147         /*
 148          * Allocate a new member structure and assign it to the next free
 149          * free memlist ident.
 150          */
 151         if ((m = (Member *)malloc(sizeof (Member))) == 0) {
 152                 _elf_seterr(EMEM_ARMEM, errno);
 153                 return (0);
 154         }
 155         if ((elf->ed_memlist == 0) || (ol->m_free == ol->m_end)) {
 156                 if ((l = (Memlist *)malloc(sizeof (Memlist) +
 157                     (sizeof (Memident) * MEMIDENTNO))) == 0) {
 158                         _elf_seterr(EMEM_ARMEM, errno);
 159                         return (0);
 160                 }
 161                 l->m_next = 0;
 162                 l->m_free = (Memident *)(l + 1);
 163                 l->m_end = (Memident *)((uintptr_t)l->m_free +
 164                     (sizeof (Memident) * MEMIDENTNO));
 165
 166                 if (elf->ed_memlist == 0)
 167                         elf->ed_memlist = l;
 168                 else
 169                         ol->m_next = l;
 170                 ol = l;
 171         }
 172         ol->m_free->m_offset = file;
 173         ol->m_free->m_member = m;
 174         ol->m_free++;
 175
 176         m->m_err = 0;
 177         (void) memcpy(m->m_name, f->ar_name, ARSZ(ar_name));
 178         m->m_name[ARSZ(ar_name)] = '\0';
 179         m->m_hdr.ar_name = m->m_name;
 180         (void) memcpy(m->m_raw, f->ar_name, ARSZ(ar_name));
 181         m->m_raw[ARSZ(ar_name)] = '\0';
 182         m->m_hdr.ar_rawname = m->m_raw;
 183         m->m_slide = 0;
 184
 185         /*
 186          * Classify file name.
 187          * If a name error occurs, delay until getarhdr().
 188          */
 189
 190         if (f->ar_name[0] != '/') {     /* regular name */
 191                 register char   *p;
 192
 193                 p = &m->m_name[sizeof (m->m_name)];
 194                 while (*--p != '/')
 195                         if (p <= m->m_name)
 196                                 break;
 197                 *p = '\0';
 198         } else if (f->ar_name[1] >= '0' && f->ar_name[1] <= '9') { /* strtab */
 199                 register unsigned long  j;
 200
 201                 j = _elf_number(&f->ar_name[1],
 202                     &f->ar_name[ARSZ(ar_name)], 10);
 203                 if (j < elf->ed_arstrsz)
 204                         m->m_hdr.ar_name = elf->ed_arstr + j;
 205                 else {
 206                         m->m_hdr.ar_name = 0;
 207                         /*LINTED*/ /* MSG_INTL(EFMT_ARSTRNM) */
 208                         m->m_err = (int)EFMT_ARSTRNM;
 209                 }
 210         } else if (f->ar_name[1] == ' ')                        /* "/" */
 211                 m->m_name[1] = '\0';
 212         else if (f->ar_name[1] == '/' && f->ar_name[2] == ' ')  /* "//" */
 213                 m->m_name[2] = '\0';
 214         else if (f->ar_name[1] == 'S' && f->ar_name[2] == 'Y' &&
 215             f->ar_name[3] == 'M' && f->ar_name[4] == '6' &&
 216             f->ar_name[5] == '4' && f->ar_name[6] == '/' &&
 217             f->ar_name[7] == ' ')                               /* "/SYM64/" */
 218                 m->m_name[7] = '\0';
 219         else {                                                  /* "/?" */
 220                 m->m_hdr.ar_name = 0;
 221                 /*LINTED*/ /* MSG_INTL(EFMT_ARUNKNM) */
 222                 m->m_err = (int)EFMT_ARUNKNM;
 223         }
 224
 225         m->m_hdr.ar_date = (time_t)_elf_number(f->ar_date,
 226             &f->ar_date[ARSZ(ar_date)], 10);
 227         /* LINTED */
 228         m->m_hdr.ar_uid = (uid_t)_elf_number(f->ar_uid,
 229             &f->ar_uid[ARSZ(ar_uid)], 10);
 230         /* LINTED */
 231         m->m_hdr.ar_gid = (gid_t)_elf_number(f->ar_gid,
 232             &f->ar_gid[ARSZ(ar_gid)], 10);
 233         /* LINTED */
 234         m->m_hdr.ar_mode = (mode_t)_elf_number(f->ar_mode,
 235             &f->ar_mode[ARSZ(ar_mode)], 8);
 236         m->m_hdr.ar_size = (off_t)_elf_number(f->ar_size,
 237             &f->ar_size[ARSZ(ar_size)], 10);
 238
 239         return (m);
 240 }
 241
 242
 243 /*
 244  * Initial archive processing
 245  *      An archive may have two special members.
 246  *
 247  *      A symbol table, named / or /SYM64/, must be first if it is present.
 248  *      Both forms use the same layout differing in the width of the
 249  *      integer type used (32 or 64-bit respectively).
 250  *
 251  *      A long name string table, named //, must precede all "normal"
 252  *      members. This string table is used to hold the names of archive
 253  *      members with names that are longer than 15 characters. It should not
 254  *      be confused with the string table found at the end of the symbol
 255  *      table, which is used to hold symbol names.
 256  *
 257  *      This code "peeks" at headers but doesn't change them.
 258  *      Later processing wants original headers.
 259  *
 260  *      String table is converted, changing '/' name terminators
 261  *      to nulls.  The last byte in the string table, which should
 262  *      be '\n', is set to nil, guaranteeing null termination.  That
 263  *      byte should be '\n', but this code doesn't check.
 264  *
 265  *      The symbol table conversion is delayed until needed.
 266  */
 267 void
 268 _elf_arinit(Elf * elf)
 269 {
 270         char                            *base = elf->ed_ident;
 271         register char                   *end = base + elf->ed_fsz;
 272         register struct ar_hdr          *a;
 273         register char                   *hdr = base + SARMAG;
 274         register char                   *mem;
 275         int                             j;
 276         size_t                          sz = SARMAG;
 277
 278         elf->ed_status = ES_COOKED;
 279         elf->ed_nextoff = SARMAG;
 280         for (j = 0; j < 2; ++j)  {      /* 2 special members */
 281                 unsigned long   n;
 282
 283                 if (((end - hdr) < sizeof (struct ar_hdr)) ||
 284                     (_elf_vm(elf, (size_t)(SARMAG),
 285                     sizeof (struct ar_hdr)) != OK_YES))
 286                         return;
 287
 288                 a = (struct ar_hdr *)hdr;
 289                 mem = (char *)a + sizeof (struct ar_hdr);
 290                 n = _elf_number(a->ar_size, &a->ar_size[ARSZ(ar_size)], 10);
 291                 if ((end - mem < n) || (a->ar_name[0] != '/') ||
 292                     ((sz = n) != n)) {
 293                         return;
 294                 }
 295
 296                 hdr = mem + sz;
 297                 if (a->ar_name[1] == ' ') {     /* 32-bit symbol table */
 298                         elf->ed_arsym = mem;
 299                         elf->ed_arsymsz = sz;
 300                         elf->ed_arsymoff = (char *)a - base;
 301                 } else if (a->ar_name[1] == '/' && a->ar_name[2] == ' ') {
 302                                                 /* Long name string table */
 303                         int     k;
 304
 305                         if (_elf_vm(elf, (size_t)(mem - elf->ed_ident),
 306                             sz) != OK_YES)
 307                                 return;
 308                         if (elf->ed_vm == 0) {
 309                                 char    *nmem;
 310                                 if ((nmem = malloc(sz)) == 0) {
 311                                         _elf_seterr(EMEM_ARSTR, errno);
 312                                         return;
 313                                 }
 314                                 (void) memcpy(nmem, mem, sz);
 315                                 elf->ed_myflags |= EDF_ASTRALLOC;
 316                                 mem = nmem;
 317                         }
 318
 319                         elf->ed_arstr = mem;
 320                         elf->ed_arstrsz = sz;
 321                         elf->ed_arstroff = (char *)a - base;
 322                         for (k = 0; k < sz; k++) {
 323                                 if (*mem == '/')
 324                                         *mem = '\0';
 325                                 ++mem;
 326                         }
 327                         *(mem - 1) = '\0';
 328                 } else if (a->ar_name[1] == 'S' && a->ar_name[2] == 'Y' &&
 329                     a->ar_name[3] == 'M' && a->ar_name[4] == '6' &&
 330                     a->ar_name[5] == '4' && a->ar_name[6] == '/' &&
 331                     a->ar_name[7] == ' ') {
 332                                                 /* 64-bit symbol table */
 333                         elf->ed_arsym = mem;
 334                         elf->ed_arsymsz = sz;
 335                         elf->ed_arsymoff = (char *)a - base;
 336                         elf->ed_myflags |= EDF_ARSYM64;
 337                 } else {
 338                         return;
 339                 }
 340                 hdr += sz & 1;
 341         }
 342 }