1 /* SPDX-License-Identifier: LGPL-2.1+ */
3 This file is part of systemd.
5 Copyright 2012 Lennart Poettering
15 #include "alloc-util.h"
18 #include "extract-word.h"
20 #include "parse-util.h"
21 #include "string-util.h"
25 #define VALID_CHARS_ENV_NAME \
30 #define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX))
33 static bool env_name_is_valid_n(const char *e, size_t n) {
42 if (e[0] >= '0' && e[0] <= '9')
45 /* POSIX says the overall size of the environment block cannot
46 * be > ARG_MAX, an individual assignment hence cannot be
47 * either. Discounting the equal sign and trailing NUL this
48 * hence leaves ARG_MAX-2 as longest possible variable
53 for (p = e; p < e + n; p++)
54 if (!strchr(VALID_CHARS_ENV_NAME, *p))
60 bool env_name_is_valid(const char *e) {
64 return env_name_is_valid_n(e, strlen(e));
67 bool env_value_is_valid(const char *e) {
71 if (!utf8_is_valid(e))
74 /* bash allows tabs and newlines in environment variables, and so
76 if (string_has_cc(e, "\t\n"))
79 /* POSIX says the overall size of the environment block cannot
80 * be > ARG_MAX, an individual assignment hence cannot be
81 * either. Discounting the shortest possible variable name of
82 * length 1, the equal sign and trailing NUL this hence leaves
83 * ARG_MAX-3 as longest possible variable value. */
84 if (strlen(e) > ARG_MAX - 3)
90 bool env_assignment_is_valid(const char *e) {
97 if (!env_name_is_valid_n(e, eq - e))
100 if (!env_value_is_valid(eq + 1))
103 /* POSIX says the overall size of the environment block cannot
104 * be > ARG_MAX, hence the individual variable assignments
105 * cannot be either, but let's leave room for one trailing NUL
107 if (strlen(e) > ARG_MAX - 1)
113 #if 0 /// UNNEEDED by elogind
114 bool strv_env_is_valid(char **e) {
120 if (!env_assignment_is_valid(*p))
123 /* Check if there are duplicate assginments */
124 k = strcspn(*p, "=");
125 STRV_FOREACH(q, p + 1)
126 if (strneq(*p, *q, k) && (*q)[k] == '=')
133 bool strv_env_name_is_valid(char **l) {
137 if (!env_name_is_valid(*p))
140 STRV_FOREACH(q, p + 1)
148 bool strv_env_name_or_assignment_is_valid(char **l) {
152 if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p))
155 STRV_FOREACH(q, p + 1)
163 static int env_append(char **r, char ***k, char **a) {
170 /* Add the entries of a to *k unless they already exist in *r
171 * in which case they are overridden instead. This assumes
172 * there is enough space in the r array. */
178 n = strcspn(*a, "=");
183 for (j = r; j < *k; j++)
184 if (strneq(*j, *a, n))
200 char **strv_env_merge(size_t n_lists, ...) {
206 /* Merges an arbitrary number of environment sets */
208 va_start(ap, n_lists);
209 for (i = 0; i < n_lists; i++) {
210 l = va_arg(ap, char**);
221 va_start(ap, n_lists);
222 for (i = 0; i < n_lists; i++) {
223 l = va_arg(ap, char**);
224 if (env_append(r, &k, l) < 0)
240 static bool env_match(const char *t, const char *pattern) {
244 /* pattern a matches string a
249 * a= does not match a
250 * a=b does not match a=
251 * a=b does not match a
252 * a=b does not match a=c */
254 if (streq(t, pattern))
257 if (!strchr(pattern, '=')) {
258 size_t l = strlen(pattern);
260 return strneq(t, pattern, l) && t[l] == '=';
266 static bool env_entry_has_name(const char *entry, const char *name) {
272 t = startswith(entry, name);
279 char **strv_env_delete(char **x, size_t n_lists, ...) {
284 /* Deletes every entry from x that is mentioned in the other
296 va_start(ap, n_lists);
297 for (v = 0; v < n_lists; v++) {
300 l = va_arg(ap, char**);
302 if (env_match(*k, *j))
327 char **strv_env_unset(char **l, const char *p) {
336 /* Drops every occurrence of the env var setting p in the
337 * string list. Edits in-place. */
339 for (f = t = l; *f; f++) {
341 if (env_match(*f, p)) {
353 char **strv_env_unset_many(char **l, ...) {
360 /* Like strv_env_unset() but applies many at once. Edits in-place. */
362 for (f = t = l; *f; f++) {
369 while ((p = va_arg(ap, const char*))) {
370 if (env_match(*f, p)) {
390 int strv_env_replace(char ***l, char *p) {
392 const char *t, *name;
396 /* Replace first occurrence of the env var or add a new one in the
397 * string list. Drop other occurences. Edits in-place. Does not copy p.
398 * p must be a valid key=value assignment.
404 name = strndupa(p, t - p);
406 for (f = *l; f && *f; f++)
407 if (env_entry_has_name(*f, name)) {
408 free_and_replace(*f, p);
409 strv_env_unset(f + 1, *f);
413 /* We didn't find a match, we need to append p or create a new strv */
414 if (strv_push(l, p) < 0)
419 char **strv_env_set(char **x, const char *p) {
422 _cleanup_strv_free_ char **r = NULL;
423 char* m[2] = { (char*) p, NULL };
425 /* Overrides the env var setting of p, returns a new copy */
427 r = new(char*, strv_length(x)+2);
432 if (env_append(r, &k, x) < 0)
435 if (env_append(r, &k, m) < 0)
443 char *strv_env_get_n(char **l, const char *name, size_t k, unsigned flags) {
451 STRV_FOREACH_BACKWARDS(i, l)
452 if (strneq(*i, name, k) &&
456 if (flags & REPLACE_ENV_USE_ENVIRONMENT) {
459 t = strndupa(name, k);
466 char *strv_env_get(char **l, const char *name) {
469 return strv_env_get_n(l, name, strlen(name), 0);
472 char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) {
478 bool duplicate = false;
480 if (!env_assignment_is_valid(*p)) {
481 if (invalid_callback)
482 invalid_callback(*p, userdata);
487 n = strcspn(*p, "=");
488 STRV_FOREACH(q, p + 1)
489 if (strneq(*p, *q, n) && (*q)[n] == '=') {
508 char *replace_env_n(const char *format, size_t n, char **env, unsigned flags) {
519 const char *e, *word = format, *test_value;
521 _cleanup_free_ char *r = NULL;
527 for (e = format, i = 0; *e && i < n; e ++, i ++)
537 k = strnappend(r, word, e-word-1);
541 free_and_replace(r, k);
546 } else if (*e == '$') {
547 k = strnappend(r, word, e-word);
551 free_and_replace(r, k);
556 } else if (flags & REPLACE_ENV_ALLOW_BRACELESS && strchr(VALID_CHARS_ENV_NAME, *e)) {
557 k = strnappend(r, word, e-word-1);
561 free_and_replace(r, k);
564 state = VARIABLE_RAW;
574 t = strv_env_get_n(env, word+2, e-word-2, flags);
580 free_and_replace(r, k);
584 } else if (*e == ':') {
585 if (!(flags & REPLACE_ENV_ALLOW_EXTENDED))
586 /* Treat this as unsupported syntax, i.e. do no replacement */
597 state = DEFAULT_VALUE;
599 state = ALTERNATE_VALUE;
608 case DEFAULT_VALUE: /* fall through */
609 case ALTERNATE_VALUE:
610 assert(flags & REPLACE_ENV_ALLOW_EXTENDED);
623 _cleanup_free_ char *v = NULL;
625 t = strv_env_get_n(env, word+2, len, flags);
627 if (t && state == ALTERNATE_VALUE)
628 t = v = replace_env_n(test_value, e-test_value, env, flags);
629 else if (!t && state == DEFAULT_VALUE)
630 t = v = replace_env_n(test_value, e-test_value, env, flags);
636 free_and_replace(r, k);
644 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
646 if (!strchr(VALID_CHARS_ENV_NAME, *e)) {
649 t = strv_env_get_n(env, word+1, e-word-1, flags);
655 free_and_replace(r, k);
664 if (state == VARIABLE_RAW) {
667 assert(flags & REPLACE_ENV_ALLOW_BRACELESS);
669 t = strv_env_get_n(env, word+1, e-word-1, flags);
670 return strappend(r, t);
672 return strnappend(r, word, e-word);
675 char **replace_env_argv(char **argv, char **env) {
679 l = strv_length(argv);
681 ret = new(char*, l+1);
685 STRV_FOREACH(i, argv) {
687 /* If $FOO appears as single word, replace it by the split up variable */
688 if ((*i)[0] == '$' && !IN_SET((*i)[1], '{', '$')) {
690 char **w, **m = NULL;
693 e = strv_env_get(env, *i+1);
697 r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES);
709 w = reallocarray(ret, l + 1, sizeof(char *));
719 memcpy(ret + k, m, q * sizeof(char*));
727 /* If ${FOO} appears as part of a word, replace it by the variable as-is */
728 ret[k] = replace_env(*i, env, 0);
741 int getenv_bool(const char *p) {
748 return parse_boolean(e);
751 #if 0 /// UNNEEDED by elogind
752 int getenv_bool_secure(const char *p) {
755 e = secure_getenv(p);
759 return parse_boolean(e);
762 int serialize_environment(FILE *f, char **environment) {
765 STRV_FOREACH(e, environment) {
766 _cleanup_free_ char *ce;
772 fprintf(f, "env=%s\n", ce);
775 /* caller should call ferror() */
780 int deserialize_environment(char ***environment, const char *line) {
787 assert(startswith(line, "env="));
788 r = cunescape(line + 4, 0, &uce);
792 return strv_env_replace(environment, uce);