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
|
/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/InterruptDisabler.h>
#include <Kernel/Process.h>
#include <Kernel/TTY/TTY.h>
namespace Kernel {
ErrorOr<FlatPtr> Process::sys$getsid(pid_t pid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
if (pid == 0)
return sid().value();
auto process = Process::from_pid_in_same_jail(pid);
if (!process)
return ESRCH;
if (sid() != process->sid())
return EPERM;
return process->sid().value();
}
ErrorOr<FlatPtr> Process::sys$setsid()
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::proc));
InterruptDisabler disabler;
bool found_process_with_same_pgid_as_my_pid = false;
TRY(Process::for_each_in_pgrp_in_same_jail(pid().value(), [&](auto&) -> ErrorOr<void> {
found_process_with_same_pgid_as_my_pid = true;
return {};
}));
if (found_process_with_same_pgid_as_my_pid)
return EPERM;
// Create a new Session and a new ProcessGroup.
auto process_group = TRY(ProcessGroup::create(ProcessGroupID(pid().value())));
m_pg.with([&](auto& pg) { pg = move(process_group); });
m_tty = nullptr;
return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {
protected_data.sid = pid().value();
return protected_data.sid.value();
});
}
ErrorOr<FlatPtr> Process::sys$getpgid(pid_t pid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
if (pid == 0)
return pgid().value();
auto process = Process::from_pid_in_same_jail(pid);
if (!process)
return ESRCH;
return process->pgid().value();
}
ErrorOr<FlatPtr> Process::sys$getpgrp()
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::stdio));
return pgid().value();
}
SessionID Process::get_sid_from_pgid(ProcessGroupID pgid)
{
// FIXME: This xor sys$setsid() uses the wrong locking mechanism.
SessionID sid { -1 };
MUST(Process::current().for_each_in_pgrp_in_same_jail(pgid, [&](auto& process) -> ErrorOr<void> {
sid = process.sid();
return {};
}));
return sid;
}
ErrorOr<FlatPtr> Process::sys$setpgid(pid_t specified_pid, pid_t specified_pgid)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this);
TRY(require_promise(Pledge::proc));
ProcessID pid = specified_pid ? ProcessID(specified_pid) : this->pid();
if (specified_pgid < 0) {
// The value of the pgid argument is less than 0, or is not a value supported by the implementation.
return EINVAL;
}
auto process = Process::from_pid_in_same_jail(pid);
if (!process)
return ESRCH;
if (process != this && process->ppid() != this->pid()) {
// The value of the pid argument does not match the process ID
// of the calling process or of a child process of the calling process.
return ESRCH;
}
if (process->is_session_leader()) {
// The process indicated by the pid argument is a session leader.
return EPERM;
}
if (process->ppid() == this->pid() && process->sid() != sid()) {
// The value of the pid argument matches the process ID of a child
// process of the calling process and the child process is not in
// the same session as the calling process.
return EPERM;
}
ProcessGroupID new_pgid = specified_pgid ? ProcessGroupID(specified_pgid) : process->pid().value();
SessionID current_sid = sid();
SessionID new_sid = get_sid_from_pgid(new_pgid);
if (new_sid != -1 && current_sid != new_sid) {
// Can't move a process between sessions.
return EPERM;
}
if (new_sid == -1 && new_pgid != process->pid().value()) {
// The value of the pgid argument is valid, but is not
// the calling pid, and is not an existing process group.
return EPERM;
}
// FIXME: There are more EPERM conditions to check for here..
auto process_group = TRY(ProcessGroup::find_or_create(new_pgid));
process->m_pg.with([&](auto& pg) { pg = move(process_group); });
return with_mutable_protected_data([&](auto& protected_data) -> ErrorOr<FlatPtr> {
auto credentials = this->credentials();
auto new_credentials = TRY(Credentials::create(
credentials->uid(),
credentials->gid(),
credentials->euid(),
credentials->egid(),
credentials->suid(),
credentials->sgid(),
credentials->extra_gids(),
new_sid,
new_pgid));
protected_data.credentials = move(new_credentials);
return 0;
});
}
ErrorOr<FlatPtr> Process::sys$get_root_session_id(pid_t force_sid)
{
TRY(require_promise(Pledge::stdio));
pid_t sid = (force_sid == -1) ? this->sid().value() : force_sid;
if (sid == 0)
return 0;
while (true) {
auto sid_process = Process::from_pid_in_same_jail(sid);
if (!sid_process)
return ESRCH;
auto parent_pid = sid_process->ppid().value();
auto parent_process = Process::from_pid_in_same_jail(parent_pid);
if (!parent_process)
return ESRCH;
pid_t parent_sid = parent_process->sid().value();
if (parent_sid == 0)
break;
sid = parent_sid;
}
return sid;
}
}
|