asmfetch/env.S at main · Pickzelle/asmfetch · GitHub

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
env_username:   .ascii "USER"
env_shell:      .ascii "SHELL"
env_desktop:    .ascii "XDG_CURRENT_DESKTOP"
env_session:    .ascii "XDG_SESSION_TYPE"

.lcomm username, 65
.lcomm username_length, 8

.lcomm shell_path, 65
.lcomm shell_path_length, 8

.lcomm desktop, 65
.lcomm desktop_length, 8

.lcomm session, 65
.lcomm session_length, 8

.lcomm target, 65

populate_envs:
	mov  rcx, 4
	mov  rsi, offset env_username
	mov  rdi, offset target
	call copy_count
	mov  rdi, offset username
	call populate_env
	mov  username_length, rcx

	mov  rcx, 5
	mov  rsi, offset env_shell
	mov  rdi, offset target
	call copy_count
	mov  rdi, offset shell_path
	call populate_env
	mov  shell_path_length, rcx

	mov  rcx, 19
	mov  rsi, offset env_desktop
	mov  rdi, offset target
	call copy_count
	mov  rdi, offset desktop
	call populate_env
	mov  desktop_length, rcx

	mov  rcx, 16
	mov  rsi, offset env_session
	mov  rdi, offset target
	call copy_count
	mov  rdi, offset session
	call populate_env
	mov  session_length, rcx

	ret

populate_env:
	mov  rax, r15
	xor  r8, r8
	xor  r9, r9
	xor  r13, r13
	xor  rsi, rsi
	call env_loop
	ret

env_loop:
	mov r14, r8
	add r14, r9
	mov bl, [rax + r14]

	cmp bl, [target + r9]
	je  env_char_matched

	xor rsi, rsi

	test bl, bl
	je   env_check_zero

skip_env:
	xor r13, r13
	inc r9

	mov r14, r8
	add r14, r9
	mov bl, [rax + r14]

	test bl, bl
	jne  skip_env

	inc r13
	inc r8
	add r8, r9
	xor r9, r9
	jmp env_loop

env_char_matched:
	inc r9

	inc rsi
	cmp rsi, rcx
	jne env_loop

	mov r14, r8
	add r14, r9
	add r14, rax
	inc r14

	mov  rsi, r14
	call copy_null
	ret

env_check_zero:
	cmp r13, 1
	jne skip_env
	ret