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1 | /* SPDX-License-Identifier: LGPL-2.1+ */ | |
2 | ||
3 | #include <stdbool.h> | |
4 | #include <stddef.h> | |
5 | #include <string.h> | |
6 | ||
7 | #include "alloc-util.h" | |
8 | #include "extract-word.h" | |
9 | #include "fileio.h" | |
10 | #include "macro.h" | |
11 | #include "parse-util.h" | |
12 | #include "proc-cmdline.h" | |
13 | #include "process-util.h" | |
14 | #include "special.h" | |
15 | #include "string-util.h" | |
16 | #include "util.h" | |
17 | #include "virt.h" | |
18 | ||
19 | int proc_cmdline(char **ret) { | |
20 | const char *e; | |
21 | assert(ret); | |
22 | ||
23 | /* For testing purposes it is sometimes useful to be able to override what we consider /proc/cmdline to be */ | |
24 | e = secure_getenv("SYSTEMD_PROC_CMDLINE"); | |
25 | if (e) { | |
26 | char *m; | |
27 | ||
28 | m = strdup(e); | |
29 | if (!m) | |
30 | return -ENOMEM; | |
31 | ||
32 | *ret = m; | |
33 | return 0; | |
34 | } | |
35 | ||
36 | if (detect_container() > 0) | |
37 | return get_process_cmdline(1, 0, false, ret); | |
38 | else | |
39 | return read_one_line_file("/proc/cmdline", ret); | |
40 | } | |
41 | ||
42 | static int proc_cmdline_extract_first(const char **p, char **ret_word, ProcCmdlineFlags flags) { | |
43 | const char *q = *p; | |
44 | int r; | |
45 | ||
46 | for (;;) { | |
47 | _cleanup_free_ char *word = NULL; | |
48 | const char *c; | |
49 | ||
50 | r = extract_first_word(&q, &word, NULL, EXTRACT_QUOTES|EXTRACT_RELAX); | |
51 | if (r < 0) | |
52 | return r; | |
53 | if (r == 0) | |
54 | break; | |
55 | ||
56 | /* Filter out arguments that are intended only for the initrd */ | |
57 | c = startswith(word, "rd."); | |
58 | if (c) { | |
59 | if (!in_initrd()) | |
60 | continue; | |
61 | ||
62 | if (FLAGS_SET(flags, PROC_CMDLINE_STRIP_RD_PREFIX)) { | |
63 | r = free_and_strdup(&word, c); | |
64 | if (r < 0) | |
65 | return r; | |
66 | } | |
67 | ||
68 | } else if (FLAGS_SET(flags, PROC_CMDLINE_RD_STRICT) && in_initrd()) | |
69 | continue; /* And optionally filter out arguments that are intended only for the host */ | |
70 | ||
71 | *p = q; | |
72 | *ret_word = TAKE_PTR(word); | |
73 | return 1; | |
74 | } | |
75 | ||
76 | *p = q; | |
77 | *ret_word = NULL; | |
78 | return 0; | |
79 | } | |
80 | ||
81 | int proc_cmdline_parse_given(const char *line, proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) { | |
82 | const char *p; | |
83 | int r; | |
84 | ||
85 | assert(parse_item); | |
86 | ||
87 | /* The PROC_CMDLINE_VALUE_OPTIONAL flag doesn't really make sense for proc_cmdline_parse(), let's make this | |
88 | * clear. */ | |
89 | assert(!FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL)); | |
90 | ||
91 | p = line; | |
92 | for (;;) { | |
93 | _cleanup_free_ char *word = NULL; | |
94 | char *value; | |
95 | ||
96 | r = proc_cmdline_extract_first(&p, &word, flags); | |
97 | if (r < 0) | |
98 | return r; | |
99 | if (r == 0) | |
100 | break; | |
101 | ||
102 | value = strchr(word, '='); | |
103 | if (value) | |
104 | *(value++) = 0; | |
105 | ||
106 | r = parse_item(word, value, data); | |
107 | if (r < 0) | |
108 | return r; | |
109 | } | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
114 | int proc_cmdline_parse(proc_cmdline_parse_t parse_item, void *data, ProcCmdlineFlags flags) { | |
115 | _cleanup_free_ char *line = NULL; | |
116 | int r; | |
117 | ||
118 | assert(parse_item); | |
119 | ||
120 | r = proc_cmdline(&line); | |
121 | if (r < 0) | |
122 | return r; | |
123 | ||
124 | return proc_cmdline_parse_given(line, parse_item, data, flags); | |
125 | } | |
126 | ||
127 | static bool relaxed_equal_char(char a, char b) { | |
128 | return a == b || | |
129 | (a == '_' && b == '-') || | |
130 | (a == '-' && b == '_'); | |
131 | } | |
132 | ||
133 | char *proc_cmdline_key_startswith(const char *s, const char *prefix) { | |
134 | assert(s); | |
135 | assert(prefix); | |
136 | ||
137 | /* Much like startswith(), but considers "-" and "_" the same */ | |
138 | ||
139 | for (; *prefix != 0; s++, prefix++) | |
140 | if (!relaxed_equal_char(*s, *prefix)) | |
141 | return NULL; | |
142 | ||
143 | return (char*) s; | |
144 | } | |
145 | ||
146 | bool proc_cmdline_key_streq(const char *x, const char *y) { | |
147 | assert(x); | |
148 | assert(y); | |
149 | ||
150 | /* Much like streq(), but considers "-" and "_" the same */ | |
151 | ||
152 | for (; *x != 0 || *y != 0; x++, y++) | |
153 | if (!relaxed_equal_char(*x, *y)) | |
154 | return false; | |
155 | ||
156 | return true; | |
157 | } | |
158 | ||
159 | int proc_cmdline_get_key(const char *key, ProcCmdlineFlags flags, char **ret_value) { | |
160 | _cleanup_free_ char *line = NULL, *ret = NULL; | |
161 | bool found = false; | |
162 | const char *p; | |
163 | int r; | |
164 | ||
165 | /* Looks for a specific key on the kernel command line. Supports three modes: | |
166 | * | |
167 | * a) The "ret_value" parameter is used. In this case a parameter beginning with the "key" string followed by | |
168 | * "=" is searched for, and the value following it is returned in "ret_value". | |
169 | * | |
170 | * b) as above, but the PROC_CMDLINE_VALUE_OPTIONAL flag is set. In this case if the key is found as a separate | |
171 | * word (i.e. not followed by "=" but instead by whitespace or the end of the command line), then this is | |
172 | * also accepted, and "value" is returned as NULL. | |
173 | * | |
174 | * c) The "ret_value" parameter is NULL. In this case a search for the exact "key" parameter is performed. | |
175 | * | |
176 | * In all three cases, > 0 is returned if the key is found, 0 if not. */ | |
177 | ||
178 | if (isempty(key)) | |
179 | return -EINVAL; | |
180 | ||
181 | if (FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL) && !ret_value) | |
182 | return -EINVAL; | |
183 | ||
184 | r = proc_cmdline(&line); | |
185 | if (r < 0) | |
186 | return r; | |
187 | ||
188 | p = line; | |
189 | for (;;) { | |
190 | _cleanup_free_ char *word = NULL; | |
191 | ||
192 | r = proc_cmdline_extract_first(&p, &word, flags); | |
193 | if (r < 0) | |
194 | return r; | |
195 | if (r == 0) | |
196 | break; | |
197 | ||
198 | if (ret_value) { | |
199 | const char *e; | |
200 | ||
201 | e = proc_cmdline_key_startswith(word, key); | |
202 | if (!e) | |
203 | continue; | |
204 | ||
205 | if (*e == '=') { | |
206 | r = free_and_strdup(&ret, e+1); | |
207 | if (r < 0) | |
208 | return r; | |
209 | ||
210 | found = true; | |
211 | ||
212 | } else if (*e == 0 && FLAGS_SET(flags, PROC_CMDLINE_VALUE_OPTIONAL)) | |
213 | found = true; | |
214 | ||
215 | } else { | |
216 | if (streq(word, key)) { | |
217 | found = true; | |
218 | break; /* we found what we were looking for */ | |
219 | } | |
220 | } | |
221 | } | |
222 | ||
223 | if (ret_value) | |
224 | *ret_value = TAKE_PTR(ret); | |
225 | ||
226 | return found; | |
227 | } | |
228 | ||
229 | int proc_cmdline_get_bool(const char *key, bool *ret) { | |
230 | _cleanup_free_ char *v = NULL; | |
231 | int r; | |
232 | ||
233 | assert(ret); | |
234 | ||
235 | r = proc_cmdline_get_key(key, PROC_CMDLINE_VALUE_OPTIONAL, &v); | |
236 | if (r < 0) | |
237 | return r; | |
238 | if (r == 0) { | |
239 | *ret = false; | |
240 | return 0; | |
241 | } | |
242 | ||
243 | if (v) { /* parameter passed */ | |
244 | r = parse_boolean(v); | |
245 | if (r < 0) | |
246 | return r; | |
247 | *ret = r; | |
248 | } else /* no parameter passed */ | |
249 | *ret = true; | |
250 | ||
251 | return 1; | |
252 | } | |
253 | ||
254 | int shall_restore_state(void) { | |
255 | bool ret; | |
256 | int r; | |
257 | ||
258 | r = proc_cmdline_get_bool("systemd.restore_state", &ret); | |
259 | if (r < 0) | |
260 | return r; | |
261 | ||
262 | return r > 0 ? ret : true; | |
263 | } | |
264 | ||
265 | static const char * const rlmap[] = { | |
266 | "emergency", SPECIAL_EMERGENCY_TARGET, | |
267 | "-b", SPECIAL_EMERGENCY_TARGET, | |
268 | "rescue", SPECIAL_RESCUE_TARGET, | |
269 | "single", SPECIAL_RESCUE_TARGET, | |
270 | "-s", SPECIAL_RESCUE_TARGET, | |
271 | "s", SPECIAL_RESCUE_TARGET, | |
272 | "S", SPECIAL_RESCUE_TARGET, | |
273 | "1", SPECIAL_RESCUE_TARGET, | |
274 | "2", SPECIAL_MULTI_USER_TARGET, | |
275 | "3", SPECIAL_MULTI_USER_TARGET, | |
276 | "4", SPECIAL_MULTI_USER_TARGET, | |
277 | "5", SPECIAL_GRAPHICAL_TARGET, | |
278 | NULL | |
279 | }; | |
280 | ||
281 | static const char * const rlmap_initrd[] = { | |
282 | "emergency", SPECIAL_EMERGENCY_TARGET, | |
283 | "rescue", SPECIAL_RESCUE_TARGET, | |
284 | NULL | |
285 | }; | |
286 | ||
287 | const char* runlevel_to_target(const char *word) { | |
288 | const char * const *rlmap_ptr; | |
289 | size_t i; | |
290 | ||
291 | if (!word) | |
292 | return NULL; | |
293 | ||
294 | if (in_initrd()) { | |
295 | word = startswith(word, "rd."); | |
296 | if (!word) | |
297 | return NULL; | |
298 | } | |
299 | ||
300 | rlmap_ptr = in_initrd() ? rlmap_initrd : rlmap; | |
301 | ||
302 | for (i = 0; rlmap_ptr[i]; i += 2) | |
303 | if (streq(word, rlmap_ptr[i])) | |
304 | return rlmap_ptr[i+1]; | |
305 | ||
306 | return NULL; | |
307 | } |