summaryrefslogtreecommitdiffhomepage
path: root/src/logic/pe_get_image_meta.c
blob: 540ac87b3ba2532026e1387cd86f3d7f2f77f48d (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include <perk/perk.h>
#include "perk_impl.h"

static int pe_free_image_meta_impl (struct pe_image_meta * meta, int status)
{
	unsigned i;

	if (meta) {
		for (i=0; i<meta->summary.num_of_implibs; i++)
			free(meta->idata[i].items);

		free(meta->idata);
		free(meta->sectbl);
		free(meta);
	}
}

void pe_free_image_meta (struct pe_image_meta * meta)
{
	pe_free_image_meta_impl(meta,0);
}

int pe_get_named_section_index (const struct pe_image_meta * m, const char * name)
{
	int i; for (i=0; i<m->coff.num_of_sections; i++)
		if (!(strcmp(name,m->sectbl[i].name)))
			return i;

	return -1;
}

int pe_get_block_section_index (const struct pe_image_meta * m, const struct pe_block * block)
{
	int i;
	uint32_t low,high;

	for (i=0; i<m->coff.num_of_sections; i++) {
		low  = m->sectbl[i].virtual_addr;
		high = low + m->sectbl[i].virtual_size;

		if ((block->rva >= low) && (block->rva + block->size <= high))
			return i;
	}

	return -1;
}

int pe_get_image_meta (const struct pe_raw_image * image, struct pe_image_meta ** meta)
{
	int i,j,s,status;
	struct pe_image_meta * m;
	char * base = image->addr;

	if (!(m = calloc(1,sizeof(*m))))
		return -1;

	m->ados = (struct pe_image_dos_hdr *)base;

	if ((status = (pe_read_dos_header(m->ados,&m->dos))))
		return pe_free_image_meta_impl(m,status);

	m->acoff = (struct pe_coff_file_hdr *)(base + m->dos.dos_lfanew);

	if ((status = (pe_read_coff_header(m->acoff,&m->coff))))
		return pe_free_image_meta_impl(m,status);

	m->aopt = (union pe_opt_hdr *)((char *)m->acoff + sizeof(m->coff));

	if ((status = (pe_read_optional_header(m->aopt,&m->opt))))
		return pe_free_image_meta_impl(m,status);

	m->asectbl = (struct pe_sec_hdr *)((char *)m->aopt  + m->coff.size_of_opt_hdr);

	if (!(m->sectbl = calloc(m->coff.num_of_sections,sizeof(*(m->sectbl)))))
		return pe_free_image_meta_impl(m,status);

	for (i=0; i<m->coff.num_of_sections; i++)
		pe_read_section_header(&m->asectbl[i],&m->sectbl[i]);

	/* .edata */
	i = pe_get_named_section_index(m,".edata");
	s = pe_get_block_section_index(m,&m->opt.dirs.export_tbl);

	if ((i >= 0) && (i != s))
		return pe_free_image_meta_impl(m,PERK_MALFORMED_IMAGE);

	if (s >= 0) {
		m->hedata = &m->sectbl[s];
		m->aedata = (struct pe_export_hdr *)(base + m->sectbl[s].ptr_to_raw_data
				+ m->opt.dirs.export_tbl.rva - m->sectbl[s].virtual_addr);
	} else if (i >= 0) {
		m->hedata = &m->sectbl[i];
		m->aedata = (struct pe_export_hdr *)(base + m->sectbl[i].ptr_to_raw_data);
	}

	if (m->aedata)
		pe_read_export_header(m->aedata,&m->edata);

	/* .idata */
	struct pe_import_hdr * 		pidata;
	struct pe_import_lookup_item *	pitem;

	i = pe_get_named_section_index(m,".idata");
	s = pe_get_block_section_index(m,&m->opt.dirs.import_tbl);

	if ((i >= 0) && (i != s))
		return pe_free_image_meta_impl(m,PERK_MALFORMED_IMAGE);

	if (s >= 0) {
		m->hidata = &m->sectbl[s];
		m->aidata = (struct pe_import_hdr *)(base + m->sectbl[s].ptr_to_raw_data
				+ m->opt.dirs.import_tbl.rva - m->sectbl[s].virtual_addr);
	} else if (i >= 0) {
		m->hidata = &m->sectbl[i];
		m->aidata = (struct pe_import_hdr *)(base + m->sectbl[i].ptr_to_raw_data);
	}

	if (m->aidata) {
		/* num of implibs */
		for (pidata=m->aidata; pidata->name_rva[0]; pidata++,m->summary.num_of_implibs++);

		/* import headers */
		if (!(m->idata = calloc(m->summary.num_of_implibs,sizeof(*(m->idata)))))
			return pe_free_image_meta_impl(m,status);

		for (i=0; i<m->summary.num_of_implibs; i++) {
			pe_read_import_header(&m->aidata[i],&m->idata[i]);

			m->idata[i].name = base + m->hidata->ptr_to_raw_data
						+ m->idata[i].name_rva - m->hidata->virtual_addr;

			if (m->idata[i].import_lookup_tbl_rva)
				m->idata[i].aitems = (struct pe_import_lookup_item *)(base + m->hidata->ptr_to_raw_data
							+ m->idata[i].import_lookup_tbl_rva - m->hidata->virtual_addr);

			#ifdef PERK_DEVEL
			printf("%s\n",m->idata[i].name);
			#endif

			/* items */
			m->idata[i].count = 0;
			if (m->idata[i].import_lookup_tbl_rva) {
				for (pitem=m->idata[i].aitems; *(uint32_t *)pitem->u.hint_name_tbl_rva; pitem++)
					m->idata[i].count++;

				if (!(m->idata[i].items = calloc(m->idata[i].count,sizeof(*(m->idata[i].items)))))
					return pe_free_image_meta_impl(m,status);
			}

			for (j=0; j<m->idata[i].count; j++) {
				if ((status = pe_read_import_lookup_item(
						&(m->idata[i].aitems[j]),
						&(m->idata[i].items[j]),
						m->opt.std.magic)))
					return pe_free_image_meta_impl(m,status);

				switch (m->opt.std.magic) {
					case PE_MAGIC_PE32:
						m->idata[i].items[j].flags = m->idata[i].items[j].u.import_lookup_entry_32;
						break;

					case PE_MAGIC_PE32_PLUS:
						m->idata[i].items[j].flags = (m->idata[i].items[j].u.import_lookup_entry_64 >> 32);
						break;
				}

				if (!m->idata[i].items[j].flags) {
					struct pe_hint_name_entry * pentry =
						(struct pe_hint_name_entry *)(base + m->hidata->ptr_to_raw_data
							+ m->idata[i].items[j].u.hint_name_tbl_rva - m->hidata->virtual_addr);

					m->idata[i].items[j].name = (char *)pentry->name;
					#ifdef PERK_DEVEL
					printf("%s\n",m->idata[i].items[j].name);
					#endif
				}
			}
		}
	}

	/* image */
	m->image.addr = image->addr;
	m->image.size = image->size;

	/* all done */
	*meta = m;
	return 0;
}