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
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
|
/****************************************************************/
/* mdso: midipix dso scavenger */
/* Copyright (C) 2015--2017 Z. Gilboa */
/* Released under GPLv2 and GPLv3; see COPYING.MDSO. */
/****************************************************************/
#include <stdio.h>
#include <stddef.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <mdso/mdso.h>
#include "mdso_object_impl.h"
#include "mdso_errinfo_impl.h"
#include "perk_consts.h"
#include "perk_structs.h"
struct mdso_symfn_references {
unsigned char refs[16];
};
struct mdso_symentry_object {
struct pe_raw_coff_object_hdr hdr;
struct pe_raw_sec_hdr sec[2];
struct mdso_symfn_references ref[1];
struct pe_raw_coff_reloc rel[2];
struct pe_raw_coff_symbol sym[9];
struct pe_raw_coff_strtbl cst;
};
int mdso_objgen_symentry(
const struct mdso_driver_ctx * dctx,
const char * sym,
FILE * fout,
struct mdso_object * vobj)
{
struct mdso_symentry_object * syment;
struct pe_raw_coff_symbol * symrec;
unsigned char * mark;
struct pe_aux_rec_section * aux;
size_t buflen;
size_t liblen;
uint32_t symlen;
uint32_t cstlen;
uint32_t objlen;
uint32_t aattr;
uint32_t sattr;
uint32_t rattr;
uint16_t oattr;
uint16_t machine;
uint16_t reltype;
uint32_t relrva;
uint32_t refoff;
uint32_t reloff;
uint32_t symoff;
uint32_t cstoff;
uint32_t datoff;
uint32_t stroff;
if ((buflen = strlen(sym)) > 1024*1024)
return MDSO_CUSTOM_ERROR(dctx,MDSO_ERR_INVALID_DATA);
if ((liblen = strlen(dctx->cctx->libname)) > 1024*1024)
return MDSO_CUSTOM_ERROR(dctx,MDSO_ERR_INVALID_DATA);
symlen = (uint32_t)buflen;
cstlen = (uint32_t)liblen + (3 * symlen) + 64;
objlen = sizeof(*syment) + cstlen;
if (vobj && vobj->addr && (vobj->size < objlen))
return MDSO_BUFFER_ERROR(dctx);
if (vobj && !vobj->addr) {
vobj->size = objlen;
return 0;
}
if (vobj)
syment = (struct mdso_symentry_object *)vobj->addr;
else if (!(syment = calloc(1,objlen)))
return MDSO_SYSTEM_ERROR(dctx);
if (dctx->cctx->drvflags & MDSO_DRIVER_QUAD_PTR) {
aattr = PE_IMAGE_SCN_ALIGN_16BYTES;
machine = PE_IMAGE_FILE_MACHINE_AMD64;
reltype = PE_IMAGE_REL_AMD64_ADDR64;
relrva = 8;
} else {
aattr = PE_IMAGE_SCN_ALIGN_4BYTES;
machine = PE_IMAGE_FILE_MACHINE_I386;
reltype = PE_IMAGE_REL_I386_DIR32;
relrva = 4;
}
sattr = PE_IMAGE_SCN_ALIGN_1BYTES;
sattr |= PE_IMAGE_SCN_MEM_READ;
sattr |= PE_IMAGE_SCN_CNT_INITIALIZED_DATA;
rattr = aattr;
rattr |= PE_IMAGE_SCN_MEM_READ;
rattr |= PE_IMAGE_SCN_CNT_INITIALIZED_DATA;
oattr = PE_IMAGE_FILE_LINE_NUMS_STRIPPED;
refoff = offsetof(struct mdso_symentry_object,ref);
reloff = offsetof(struct mdso_symentry_object,rel);
symoff = offsetof(struct mdso_symentry_object,sym);
cstoff = offsetof(struct pe_raw_coff_strtbl,cst_data);
datoff = 0;
stroff = objlen - symlen - 16;
stroff += 0xf;
stroff |= 0xf;
stroff ^= 0xf;
/* coff object header */
mdso_obj_write_short(syment->hdr.cfh_machine,machine);
mdso_obj_write_short(syment->hdr.cfh_num_of_sections,2);
mdso_obj_write_long(syment->hdr.cfh_ptr_to_sym_tbl,symoff);
mdso_obj_write_long(syment->hdr.cfh_num_of_syms,9);
mdso_obj_write_short(syment->hdr.cfh_characteristics,oattr);
/* .dsostrs section header */
memcpy(syment->sec[0].sh_name,".dsostrs",8);
mdso_obj_write_long(syment->sec[0].sh_size_of_raw_data,symlen+1);
mdso_obj_write_long(syment->sec[0].sh_ptr_to_raw_data,stroff);
mdso_obj_write_long(syment->sec[0].sh_characteristics,sattr);
/* .dsosyms section header */
memcpy(syment->sec[1].sh_name,".dsosyms",8);
mdso_obj_write_long(syment->sec[1].sh_size_of_raw_data,2*relrva);
mdso_obj_write_long(syment->sec[1].sh_ptr_to_raw_data,refoff);
mdso_obj_write_long(syment->sec[1].sh_ptr_to_relocs,reloff);
mdso_obj_write_short(syment->sec[1].sh_num_of_relocs,2);
mdso_obj_write_long(syment->sec[1].sh_characteristics,rattr);
/* .dsosyms relocation record: .symstr */
mdso_obj_write_long(syment->rel[0].rel_sym,6);
mdso_obj_write_long(syment->rel[0].rel_rva,0);
mdso_obj_write_short(syment->rel[0].rel_type,reltype);
/* .dsosyms relocation record: .dsometa_libname */
mdso_obj_write_long(syment->rel[1].rel_sym,8);
mdso_obj_write_long(syment->rel[1].rel_rva,relrva);
mdso_obj_write_short(syment->rel[1].rel_type,reltype);
/* coff string table */
mdso_obj_write_long(syment->cst.cst_size,cstlen);
/* coff symbol table */
symrec = syment->sym;
mark = syment->cst.cst_data;
/* coff symbol: .file */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_FILE;
symrec[0].cs_num_of_aux_symbols[0] = 1;
mdso_obj_write_short(&symrec[0].cs_section_number[0],PE_IMAGE_SYM_DEBUG);
mdso_obj_write_long(&symrec[1].cs_name[4],cstoff+datoff);
memcpy(symrec[0].cs_name,".file",5);
memcpy(&mark[0],".",1);
memcpy(&mark[1],sym,symlen);
memcpy(&mark[1+symlen],"_symentry.s",11);
datoff += 13 + symlen;
mark += 13 + symlen;
symrec += 2;
/* coff symbol: .dsostrs */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
symrec[0].cs_num_of_aux_symbols[0] = 1;
mdso_obj_write_short(symrec[0].cs_section_number,1);
memcpy(symrec[0].cs_name,".dsostrs",8);
aux = (struct pe_aux_rec_section *)&symrec[1];
mdso_obj_write_long(aux->aux_size,symlen+1);
mdso_obj_write_short(aux->aux_num_of_relocs,0);
datoff += 0;
mark += 0;
symrec += 2;
/* coff symbol: .dsosyms */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
symrec[0].cs_num_of_aux_symbols[0] = 1;
mdso_obj_write_short(symrec[0].cs_section_number,2);
memcpy(symrec[0].cs_name,".dsosyms",8);
aux = (struct pe_aux_rec_section *)&symrec[1];
mdso_obj_write_long(aux->aux_size,2*relrva);
mdso_obj_write_short(aux->aux_num_of_relocs,2);
datoff += 0;
mark += 0;
symrec += 2;
/* coff symbol: .symstr */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_STATIC;
symrec[0].cs_num_of_aux_symbols[0] = 0;
mdso_obj_write_short(symrec[0].cs_section_number,1);
memcpy(symrec[0].cs_name,".symstr",7);
datoff += 0;
mark += 0;
symrec += 1;
/* coff symbol: __imp_sym */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_EXTERNAL;
symrec[0].cs_num_of_aux_symbols[0] = 0;
mdso_obj_write_short(symrec[0].cs_section_number,2);
mdso_obj_write_long(&symrec[0].cs_name[4],cstoff+datoff);
if (dctx->cctx->drvflags & MDSO_DRIVER_QUAD_PTR) {
memcpy(&mark[0],"__imp_",6);
memcpy(&mark[6],sym,symlen);
} else {
memcpy(&mark[0],"__imp_",6);
memcpy(&mark[7],sym,symlen);
mark[6] = '_';
datoff++;
mark++;
}
datoff += 7 + symlen;
mark += 7 + symlen;
symrec += 1;
/* coff symbol: .dsometa_libname */
symrec[0].cs_storage_class[0] = PE_IMAGE_SYM_CLASS_EXTERNAL;
symrec[0].cs_num_of_aux_symbols[0] = 0;
mdso_obj_write_short(symrec[0].cs_section_number,0);
mdso_obj_write_long(&symrec[0].cs_name[4],cstoff+datoff);
memcpy(&mark[0],".dsometa_",9);
memcpy(&mark[9],dctx->cctx->libname,liblen);
/* .symstr */
mark = syment->hdr.cfh_machine;
memcpy(&mark[stroff],sym,symlen);
/* tada */
if (fout)
if (fwrite(syment,objlen,1,fout) == 0)
return MDSO_FILE_ERROR(dctx);
if (!vobj)
free(syment);
return 0;
}
|
