1 /*-
2 * Copyright (c) 2016 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 <sys/param.h>
28 #include <err.h>
29 #include <gelf.h>
30 #include <libpe.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <time.h>
34
35 #include "elfcopy.h"
36
37 ELFTC_VCSID("$Id: pe.c 3508 2016-12-27 06:19:39Z kaiwang27 $");
38
39 /* Convert ELF object to Portable Executable (PE). */
40 void
create_pe(struct elfcopy * ecp,int ifd,int ofd)41 create_pe(struct elfcopy *ecp, int ifd, int ofd)
42 {
43 Elf *e;
44 Elf_Scn *scn;
45 Elf_Data *d;
46 GElf_Ehdr eh;
47 GElf_Shdr sh;
48 PE *pe;
49 PE_Scn *ps;
50 PE_SecHdr psh;
51 PE_CoffHdr pch;
52 PE_OptHdr poh;
53 PE_Object po;
54 PE_Buffer *pb;
55 const char *name;
56 size_t indx;
57 time_t timestamp;
58 int elferr;
59
60 if (ecp->otf == ETF_EFI || ecp->oem == EM_X86_64)
61 po = PE_O_PE32P;
62 else
63 po = PE_O_PE32;
64
65 if ((e = elf_begin(ifd, ELF_C_READ, NULL)) == NULL)
66 errx(EXIT_FAILURE, "elf_begin() failed: %s",
67 elf_errmsg(-1));
68
69 if (gelf_getehdr(e, &eh) == NULL)
70 errx(EXIT_FAILURE, "gelf_getehdr() failed: %s",
71 elf_errmsg(-1));
72
73 if (elf_getshstrndx(e, &indx) == 0)
74 errx(EXIT_FAILURE, "elf_getshstrndx() failed: %s",
75 elf_errmsg(-1));
76
77 if ((pe = pe_init(ofd, PE_C_WRITE, po)) == NULL)
78 err(EXIT_FAILURE, "pe_init() failed");
79
80 /* Setup PE COFF header. */
81 memset(&pch, 0, sizeof(pch));
82 switch (ecp->oem) {
83 case EM_386:
84 pch.ch_machine = IMAGE_FILE_MACHINE_I386;
85 break;
86 case EM_X86_64:
87 pch.ch_machine = IMAGE_FILE_MACHINE_AMD64;
88 break;
89 default:
90 pch.ch_machine = IMAGE_FILE_MACHINE_UNKNOWN;
91 break;
92 }
93 if (elftc_timestamp(×tamp) != 0)
94 err(EXIT_FAILURE, "elftc_timestamp");
95 pch.ch_timestamp = (uint32_t) timestamp;
96 if (pe_update_coff_header(pe, &pch) < 0)
97 err(EXIT_FAILURE, "pe_update_coff_header() failed");
98
99 /* Setup PE optional header. */
100 memset(&poh, 0, sizeof(poh));
101 if (ecp->otf == ETF_EFI)
102 poh.oh_subsystem = IMAGE_SUBSYSTEM_EFI_APPLICATION;
103 poh.oh_entry = (uint32_t) eh.e_entry;
104
105 /*
106 * Default section alignment and file alignment. (Here the
107 * section alignment is set to the default page size of the
108 * archs supported. We should use different section alignment
109 * for some arch. (e.g. IA64)
110 */
111 poh.oh_secalign = 0x1000;
112 poh.oh_filealign = 0x200;
113
114 /* Copy sections. */
115 scn = NULL;
116 while ((scn = elf_nextscn(e, scn)) != NULL) {
117
118 /*
119 * Read in ELF section.
120 */
121
122 if (gelf_getshdr(scn, &sh) == NULL) {
123 warnx("gelf_getshdr() failed: %s", elf_errmsg(-1));
124 (void) elf_errno();
125 continue;
126 }
127 if ((name = elf_strptr(e, indx, sh.sh_name)) ==
128 NULL) {
129 warnx("elf_strptr() failed: %s", elf_errmsg(-1));
130 (void) elf_errno();
131 continue;
132 }
133
134 /* Skip sections unneeded. */
135 if (strcmp(name, ".shstrtab") == 0 ||
136 strcmp(name, ".symtab") == 0 ||
137 strcmp(name, ".strtab") == 0)
138 continue;
139
140 if ((d = elf_getdata(scn, NULL)) == NULL) {
141 warnx("elf_getdata() failed: %s", elf_errmsg(-1));
142 (void) elf_errno();
143 continue;
144 }
145
146 if (strcmp(name, ".text") == 0) {
147 poh.oh_textbase = (uint32_t) sh.sh_addr;
148 poh.oh_textsize = (uint32_t) roundup(sh.sh_size,
149 poh.oh_filealign);
150 } else {
151 if (po == PE_O_PE32 && strcmp(name, ".data") == 0)
152 poh.oh_database = sh.sh_addr;
153 if (sh.sh_type == SHT_NOBITS)
154 poh.oh_bsssize += (uint32_t)
155 roundup(sh.sh_size, poh.oh_filealign);
156 else if (sh.sh_flags & SHF_ALLOC)
157 poh.oh_datasize += (uint32_t)
158 roundup(sh.sh_size, poh.oh_filealign);
159 }
160
161 /*
162 * Create PE/COFF section.
163 */
164
165 if ((ps = pe_newscn(pe)) == NULL) {
166 warn("pe_newscn() failed");
167 continue;
168 }
169
170 /*
171 * Setup PE/COFF section header. The section name is not
172 * NUL-terminated if its length happens to be 8. Long
173 * section name should be truncated for PE image according
174 * to the PE/COFF specification.
175 */
176 memset(&psh, 0, sizeof(psh));
177 strncpy(psh.sh_name, name, sizeof(psh.sh_name));
178 psh.sh_addr = sh.sh_addr;
179 psh.sh_virtsize = sh.sh_size;
180 if (sh.sh_type != SHT_NOBITS)
181 psh.sh_rawsize = roundup(sh.sh_size, poh.oh_filealign);
182 else
183 psh.sh_char |= IMAGE_SCN_CNT_UNINITIALIZED_DATA;
184
185 /*
186 * Translate ELF section flags to PE/COFF section flags.
187 */
188 psh.sh_char |= IMAGE_SCN_MEM_READ;
189 if (sh.sh_flags & SHF_WRITE)
190 psh.sh_char |= IMAGE_SCN_MEM_WRITE;
191 if (sh.sh_flags & SHF_EXECINSTR)
192 psh.sh_char |= IMAGE_SCN_MEM_EXECUTE |
193 IMAGE_SCN_CNT_CODE;
194 if ((sh.sh_flags & SHF_ALLOC) && (psh.sh_char & 0xF0) == 0)
195 psh.sh_char |= IMAGE_SCN_CNT_INITIALIZED_DATA;
196
197 /* Mark relocation section "discardable". */
198 if (strcmp(name, ".reloc") == 0)
199 psh.sh_char |= IMAGE_SCN_MEM_DISCARDABLE;
200
201 if (pe_update_section_header(ps, &psh) < 0) {
202 warn("pe_update_section_header() failed");
203 continue;
204 }
205
206 /* Copy section content. */
207 if ((pb = pe_newbuffer(ps)) == NULL) {
208 warn("pe_newbuffer() failed");
209 continue;
210 }
211 pb->pb_align = 1;
212 pb->pb_off = 0;
213 if (sh.sh_type != SHT_NOBITS) {
214 pb->pb_size = roundup(sh.sh_size, poh.oh_filealign);
215 if ((pb->pb_buf = calloc(1, pb->pb_size)) == NULL) {
216 warn("calloc failed");
217 continue;
218 }
219 memcpy(pb->pb_buf, d->d_buf, sh.sh_size);
220 }
221 }
222 elferr = elf_errno();
223 if (elferr != 0)
224 warnx("elf_nextscn() failed: %s", elf_errmsg(elferr));
225
226 /* Update PE optional header. */
227 if (pe_update_opt_header(pe, &poh) < 0)
228 err(EXIT_FAILURE, "pe_update_opt_header() failed");
229
230 /* Write out PE/COFF object. */
231 if (pe_update(pe) < 0)
232 err(EXIT_FAILURE, "pe_update() failed");
233
234 pe_finish(pe);
235 elf_end(e);
236 }
237