1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Helper functions for handling target threads/cpus |
4 | * |
5 | * Copyright (C) 2012, LG Electronics, Namhyung Kim <namhyung.kim@lge.com> |
6 | */ |
7 | |
8 | #include "target.h" |
9 | |
10 | #include <pwd.h> |
11 | #include <stdio.h> |
12 | #include <stdlib.h> |
13 | #include <string.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/string.h> |
16 | |
17 | enum target_errno target__validate(struct target *target) |
18 | { |
19 | enum target_errno ret = TARGET_ERRNO__SUCCESS; |
20 | |
21 | if (target->pid) |
22 | target->tid = target->pid; |
23 | |
24 | /* CPU and PID are mutually exclusive */ |
25 | if (target->tid && target->cpu_list) { |
26 | target->cpu_list = NULL; |
27 | if (ret == TARGET_ERRNO__SUCCESS) |
28 | ret = TARGET_ERRNO__PID_OVERRIDE_CPU; |
29 | } |
30 | |
31 | /* UID and PID are mutually exclusive */ |
32 | if (target->tid && target->uid_str) { |
33 | target->uid_str = NULL; |
34 | if (ret == TARGET_ERRNO__SUCCESS) |
35 | ret = TARGET_ERRNO__PID_OVERRIDE_UID; |
36 | } |
37 | |
38 | /* UID and CPU are mutually exclusive */ |
39 | if (target->uid_str && target->cpu_list) { |
40 | target->cpu_list = NULL; |
41 | if (ret == TARGET_ERRNO__SUCCESS) |
42 | ret = TARGET_ERRNO__UID_OVERRIDE_CPU; |
43 | } |
44 | |
45 | /* PID and SYSTEM are mutually exclusive */ |
46 | if (target->tid && target->system_wide) { |
47 | target->system_wide = false; |
48 | if (ret == TARGET_ERRNO__SUCCESS) |
49 | ret = TARGET_ERRNO__PID_OVERRIDE_SYSTEM; |
50 | } |
51 | |
52 | /* UID and SYSTEM are mutually exclusive */ |
53 | if (target->uid_str && target->system_wide) { |
54 | target->system_wide = false; |
55 | if (ret == TARGET_ERRNO__SUCCESS) |
56 | ret = TARGET_ERRNO__UID_OVERRIDE_SYSTEM; |
57 | } |
58 | |
59 | /* BPF and CPU are mutually exclusive */ |
60 | if (target->bpf_str && target->cpu_list) { |
61 | target->cpu_list = NULL; |
62 | if (ret == TARGET_ERRNO__SUCCESS) |
63 | ret = TARGET_ERRNO__BPF_OVERRIDE_CPU; |
64 | } |
65 | |
66 | /* BPF and PID/TID are mutually exclusive */ |
67 | if (target->bpf_str && target->tid) { |
68 | target->tid = NULL; |
69 | if (ret == TARGET_ERRNO__SUCCESS) |
70 | ret = TARGET_ERRNO__BPF_OVERRIDE_PID; |
71 | } |
72 | |
73 | /* BPF and UID are mutually exclusive */ |
74 | if (target->bpf_str && target->uid_str) { |
75 | target->uid_str = NULL; |
76 | if (ret == TARGET_ERRNO__SUCCESS) |
77 | ret = TARGET_ERRNO__BPF_OVERRIDE_UID; |
78 | } |
79 | |
80 | /* BPF and THREADS are mutually exclusive */ |
81 | if (target->bpf_str && target->per_thread) { |
82 | target->per_thread = false; |
83 | if (ret == TARGET_ERRNO__SUCCESS) |
84 | ret = TARGET_ERRNO__BPF_OVERRIDE_THREAD; |
85 | } |
86 | |
87 | /* THREAD and SYSTEM/CPU are mutually exclusive */ |
88 | if (target->per_thread && (target->system_wide || target->cpu_list)) { |
89 | target->per_thread = false; |
90 | if (ret == TARGET_ERRNO__SUCCESS) |
91 | ret = TARGET_ERRNO__SYSTEM_OVERRIDE_THREAD; |
92 | } |
93 | |
94 | return ret; |
95 | } |
96 | |
97 | enum target_errno target__parse_uid(struct target *target) |
98 | { |
99 | struct passwd pwd, *result; |
100 | char buf[1024]; |
101 | const char *str = target->uid_str; |
102 | |
103 | target->uid = UINT_MAX; |
104 | if (str == NULL) |
105 | return TARGET_ERRNO__SUCCESS; |
106 | |
107 | /* Try user name first */ |
108 | getpwnam_r(str, &pwd, buf, sizeof(buf), &result); |
109 | |
110 | if (result == NULL) { |
111 | /* |
112 | * The user name not found. Maybe it's a UID number. |
113 | */ |
114 | char *endptr; |
115 | int uid = strtol(str, &endptr, 10); |
116 | |
117 | if (*endptr != '\0') |
118 | return TARGET_ERRNO__INVALID_UID; |
119 | |
120 | getpwuid_r(uid, &pwd, buf, sizeof(buf), &result); |
121 | |
122 | if (result == NULL) |
123 | return TARGET_ERRNO__USER_NOT_FOUND; |
124 | } |
125 | |
126 | target->uid = result->pw_uid; |
127 | return TARGET_ERRNO__SUCCESS; |
128 | } |
129 | |
130 | /* |
131 | * This must have a same ordering as the enum target_errno. |
132 | */ |
133 | static const char *target__error_str[] = { |
134 | "PID/TID switch overriding CPU" , |
135 | "PID/TID switch overriding UID" , |
136 | "UID switch overriding CPU" , |
137 | "PID/TID switch overriding SYSTEM" , |
138 | "UID switch overriding SYSTEM" , |
139 | "SYSTEM/CPU switch overriding PER-THREAD" , |
140 | "BPF switch overriding CPU" , |
141 | "BPF switch overriding PID/TID" , |
142 | "BPF switch overriding UID" , |
143 | "BPF switch overriding THREAD" , |
144 | "Invalid User: %s" , |
145 | "Problems obtaining information for user %s" , |
146 | }; |
147 | |
148 | int target__strerror(struct target *target, int errnum, |
149 | char *buf, size_t buflen) |
150 | { |
151 | int idx; |
152 | const char *msg; |
153 | |
154 | BUG_ON(buflen == 0); |
155 | |
156 | if (errnum >= 0) { |
157 | str_error_r(errnum, buf, buflen); |
158 | return 0; |
159 | } |
160 | |
161 | if (errnum < __TARGET_ERRNO__START || errnum >= __TARGET_ERRNO__END) |
162 | return -1; |
163 | |
164 | idx = errnum - __TARGET_ERRNO__START; |
165 | msg = target__error_str[idx]; |
166 | |
167 | switch (errnum) { |
168 | case TARGET_ERRNO__PID_OVERRIDE_CPU ... |
169 | TARGET_ERRNO__BPF_OVERRIDE_THREAD: |
170 | snprintf(buf, size: buflen, fmt: "%s" , msg); |
171 | break; |
172 | |
173 | case TARGET_ERRNO__INVALID_UID: |
174 | case TARGET_ERRNO__USER_NOT_FOUND: |
175 | snprintf(buf, size: buflen, fmt: msg, target->uid_str); |
176 | break; |
177 | |
178 | default: |
179 | /* cannot reach here */ |
180 | break; |
181 | } |
182 | |
183 | return 0; |
184 | } |
185 | |