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, buflen, "%s", msg);
171 break;
172
173 case TARGET_ERRNO__INVALID_UID:
174 case TARGET_ERRNO__USER_NOT_FOUND:
175 snprintf(buf, buflen, msg, target->uid_str);
176 break;
177
178 default:
179 /* cannot reach here */
180 break;
181 }
182
183 return 0;
184 }
185
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