xref: /freebsd/contrib/elftoolchain/libpe/pe_dos.c (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1 /*-
2  * Copyright (c) 2015 Kai Wang
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <assert.h>
28 #include <errno.h>
29 #include <stdlib.h>
30 #include <string.h>
31 
32 #include "_libpe.h"
33 
34 ELFTC_VCSID("$Id: pe_dos.c 3312 2016-01-10 09:23:51Z kaiwang27 $");
35 
36 PE_DosHdr *
37 pe_msdos_header(PE *pe)
38 {
39 
40 	if (pe == NULL) {
41 		errno = EINVAL;
42 		return (NULL);
43 	}
44 
45 	if (pe->pe_dh == NULL) {
46 		errno = ENOENT;
47 		return (NULL);
48 	}
49 
50 	return (pe->pe_dh);
51 }
52 
53 char *
54 pe_msdos_stub(PE *pe, size_t *len)
55 {
56 
57 	if (pe == NULL || len == NULL) {
58 		errno = EINVAL;
59 		return (NULL);
60 	}
61 
62 	if (pe->pe_stub_ex > 0 &&
63 	    (pe->pe_flags & LIBPE_F_LOAD_DOS_STUB) == 0) {
64 		assert((pe->pe_flags & LIBPE_F_SPECIAL_FILE) == 0);
65 		(void) libpe_read_msdos_stub(pe);
66 	}
67 
68 	*len = sizeof(PE_DosHdr) + pe->pe_stub_ex;
69 
70 	return (pe->pe_stub);
71 }
72 
73 int
74 ps_update_msdos_header(PE *pe, PE_DosHdr *dh)
75 {
76 
77 	if (pe == NULL || dh == NULL) {
78 		errno = EINVAL;
79 		return (-1);
80 	}
81 
82 	if (pe->pe_cmd == PE_C_READ || pe->pe_flags & LIBPE_F_FD_DONE) {
83 		errno = EACCES;
84 		return (-1);
85 	}
86 
87 	if (pe->pe_dh == NULL) {
88 		if ((pe->pe_dh = malloc(sizeof(PE_DosHdr))) == NULL) {
89 			errno = ENOMEM;
90 			return (-1);
91 		}
92 	}
93 
94 	*pe->pe_dh = *dh;
95 
96 	pe->pe_flags |= LIBPE_F_DIRTY_DOS_HEADER;
97 
98 	return (0);
99 }
100 
101 int
102 ps_update_msdos_stub(PE *pe, char *dos_stub, size_t sz)
103 {
104 
105 	if (pe == NULL || dos_stub == NULL || sz == 0) {
106 		errno = EINVAL;
107 		return (-1);
108 	}
109 
110 	if (pe->pe_cmd == PE_C_READ || pe->pe_flags & LIBPE_F_FD_DONE) {
111 		errno = EACCES;
112 		return (-1);
113 	}
114 
115 	pe->pe_stub_app = dos_stub;
116 	pe->pe_stub_app_sz = sz;
117 
118 	return (0);
119 }
120