1*2de3b87aSKai Wang /*-
2*2de3b87aSKai Wang * Copyright (c) 2006,2008-2011 Joseph Koshy
3*2de3b87aSKai Wang * All rights reserved.
4*2de3b87aSKai Wang *
5*2de3b87aSKai Wang * Redistribution and use in source and binary forms, with or without
6*2de3b87aSKai Wang * modification, are permitted provided that the following conditions
7*2de3b87aSKai Wang * are met:
8*2de3b87aSKai Wang * 1. Redistributions of source code must retain the above copyright
9*2de3b87aSKai Wang * notice, this list of conditions and the following disclaimer.
10*2de3b87aSKai Wang * 2. Redistributions in binary form must reproduce the above copyright
11*2de3b87aSKai Wang * notice, this list of conditions and the following disclaimer in the
12*2de3b87aSKai Wang * documentation and/or other materials provided with the distribution.
13*2de3b87aSKai Wang *
14*2de3b87aSKai Wang * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15*2de3b87aSKai Wang * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*2de3b87aSKai Wang * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*2de3b87aSKai Wang * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*2de3b87aSKai Wang * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*2de3b87aSKai Wang * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*2de3b87aSKai Wang * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*2de3b87aSKai Wang * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*2de3b87aSKai Wang * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*2de3b87aSKai Wang * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*2de3b87aSKai Wang * SUCH DAMAGE.
25*2de3b87aSKai Wang */
26*2de3b87aSKai Wang
27*2de3b87aSKai Wang #include <libelf.h>
28*2de3b87aSKai Wang
29*2de3b87aSKai Wang #include "_libelf.h"
30*2de3b87aSKai Wang
31*2de3b87aSKai Wang ELFTC_VCSID("$Id: elf_begin.c 2364 2011-12-28 17:55:25Z jkoshy $");
32*2de3b87aSKai Wang
33*2de3b87aSKai Wang Elf *
elf_begin(int fd,Elf_Cmd c,Elf * a)34*2de3b87aSKai Wang elf_begin(int fd, Elf_Cmd c, Elf *a)
35*2de3b87aSKai Wang {
36*2de3b87aSKai Wang Elf *e;
37*2de3b87aSKai Wang
38*2de3b87aSKai Wang e = NULL;
39*2de3b87aSKai Wang
40*2de3b87aSKai Wang if (LIBELF_PRIVATE(version) == EV_NONE) {
41*2de3b87aSKai Wang LIBELF_SET_ERROR(SEQUENCE, 0);
42*2de3b87aSKai Wang return (NULL);
43*2de3b87aSKai Wang }
44*2de3b87aSKai Wang
45*2de3b87aSKai Wang switch (c) {
46*2de3b87aSKai Wang case ELF_C_NULL:
47*2de3b87aSKai Wang return (NULL);
48*2de3b87aSKai Wang
49*2de3b87aSKai Wang case ELF_C_WRITE:
50*2de3b87aSKai Wang /*
51*2de3b87aSKai Wang * The ELF_C_WRITE command is required to ignore the
52*2de3b87aSKai Wang * descriptor passed in.
53*2de3b87aSKai Wang */
54*2de3b87aSKai Wang a = NULL;
55*2de3b87aSKai Wang break;
56*2de3b87aSKai Wang
57*2de3b87aSKai Wang case ELF_C_RDWR:
58*2de3b87aSKai Wang if (a != NULL) { /* not allowed for ar(1) archives. */
59*2de3b87aSKai Wang LIBELF_SET_ERROR(ARGUMENT, 0);
60*2de3b87aSKai Wang return (NULL);
61*2de3b87aSKai Wang }
62*2de3b87aSKai Wang /*FALLTHROUGH*/
63*2de3b87aSKai Wang case ELF_C_READ:
64*2de3b87aSKai Wang /*
65*2de3b87aSKai Wang * Descriptor `a' could be for a regular ELF file, or
66*2de3b87aSKai Wang * for an ar(1) archive. If descriptor `a' was opened
67*2de3b87aSKai Wang * using a valid file descriptor, we need to check if
68*2de3b87aSKai Wang * the passed in `fd' value matches the original one.
69*2de3b87aSKai Wang */
70*2de3b87aSKai Wang if (a &&
71*2de3b87aSKai Wang ((a->e_fd != -1 && a->e_fd != fd) || c != a->e_cmd)) {
72*2de3b87aSKai Wang LIBELF_SET_ERROR(ARGUMENT, 0);
73*2de3b87aSKai Wang return (NULL);
74*2de3b87aSKai Wang }
75*2de3b87aSKai Wang break;
76*2de3b87aSKai Wang
77*2de3b87aSKai Wang default:
78*2de3b87aSKai Wang LIBELF_SET_ERROR(ARGUMENT, 0);
79*2de3b87aSKai Wang return (NULL);
80*2de3b87aSKai Wang
81*2de3b87aSKai Wang }
82*2de3b87aSKai Wang
83*2de3b87aSKai Wang if (a == NULL)
84*2de3b87aSKai Wang e = _libelf_open_object(fd, c, 1);
85*2de3b87aSKai Wang else if (a->e_kind == ELF_K_AR)
86*2de3b87aSKai Wang e = _libelf_ar_open_member(a->e_fd, c, a);
87*2de3b87aSKai Wang else
88*2de3b87aSKai Wang (e = a)->e_activations++;
89*2de3b87aSKai Wang
90*2de3b87aSKai Wang return (e);
91*2de3b87aSKai Wang }
92