diff options
author | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-01 15:52:09 -0400 |
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committer | Luke Shumaker <lukeshu@sbcglobal.net> | 2016-06-01 15:52:09 -0400 |
commit | bb110bc7433adeb79b4814ef2a1c04e2160be396 (patch) | |
tree | c45048907133b8bbd7e2d86b350436a9ad0ffe8b /src/libbasic/env-util.c | |
parent | 192d82912f055a2b4a2b5c02f0ef69b002322bba (diff) |
./move.sh
Diffstat (limited to 'src/libbasic/env-util.c')
-rw-r--r-- | src/libbasic/env-util.c | 624 |
1 files changed, 624 insertions, 0 deletions
diff --git a/src/libbasic/env-util.c b/src/libbasic/env-util.c new file mode 100644 index 0000000000..7f5fddb700 --- /dev/null +++ b/src/libbasic/env-util.c @@ -0,0 +1,624 @@ +/*** + This file is part of systemd. + + Copyright 2012 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <limits.h> +#include <stdarg.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "env-util.h" +#include "extract-word.h" +#include "macro.h" +#include "parse-util.h" +#include "string-util.h" +#include "strv.h" +#include "utf8.h" + +#define VALID_CHARS_ENV_NAME \ + DIGITS LETTERS \ + "_" + +#ifndef ARG_MAX +#define ARG_MAX ((size_t) sysconf(_SC_ARG_MAX)) +#endif + +static bool env_name_is_valid_n(const char *e, size_t n) { + const char *p; + + if (!e) + return false; + + if (n <= 0) + return false; + + if (e[0] >= '0' && e[0] <= '9') + return false; + + /* POSIX says the overall size of the environment block cannot + * be > ARG_MAX, an individual assignment hence cannot be + * either. Discounting the equal sign and trailing NUL this + * hence leaves ARG_MAX-2 as longest possible variable + * name. */ + if (n > ARG_MAX - 2) + return false; + + for (p = e; p < e + n; p++) + if (!strchr(VALID_CHARS_ENV_NAME, *p)) + return false; + + return true; +} + +bool env_name_is_valid(const char *e) { + if (!e) + return false; + + return env_name_is_valid_n(e, strlen(e)); +} + +bool env_value_is_valid(const char *e) { + if (!e) + return false; + + if (!utf8_is_valid(e)) + return false; + + /* bash allows tabs in environment variables, and so should + * we */ + if (string_has_cc(e, "\t")) + return false; + + /* POSIX says the overall size of the environment block cannot + * be > ARG_MAX, an individual assignment hence cannot be + * either. Discounting the shortest possible variable name of + * length 1, the equal sign and trailing NUL this hence leaves + * ARG_MAX-3 as longest possible variable value. */ + if (strlen(e) > ARG_MAX - 3) + return false; + + return true; +} + +bool env_assignment_is_valid(const char *e) { + const char *eq; + + eq = strchr(e, '='); + if (!eq) + return false; + + if (!env_name_is_valid_n(e, eq - e)) + return false; + + if (!env_value_is_valid(eq + 1)) + return false; + + /* POSIX says the overall size of the environment block cannot + * be > ARG_MAX, hence the individual variable assignments + * cannot be either, but let's leave room for one trailing NUL + * byte. */ + if (strlen(e) > ARG_MAX - 1) + return false; + + return true; +} + +bool strv_env_is_valid(char **e) { + char **p, **q; + + STRV_FOREACH(p, e) { + size_t k; + + if (!env_assignment_is_valid(*p)) + return false; + + /* Check if there are duplicate assginments */ + k = strcspn(*p, "="); + STRV_FOREACH(q, p + 1) + if (strneq(*p, *q, k) && (*q)[k] == '=') + return false; + } + + return true; +} + +bool strv_env_name_is_valid(char **l) { + char **p, **q; + + STRV_FOREACH(p, l) { + if (!env_name_is_valid(*p)) + return false; + + STRV_FOREACH(q, p + 1) + if (streq(*p, *q)) + return false; + } + + return true; +} + +bool strv_env_name_or_assignment_is_valid(char **l) { + char **p, **q; + + STRV_FOREACH(p, l) { + if (!env_assignment_is_valid(*p) && !env_name_is_valid(*p)) + return false; + + STRV_FOREACH(q, p + 1) + if (streq(*p, *q)) + return false; + } + + return true; +} + +static int env_append(char **r, char ***k, char **a) { + assert(r); + assert(k); + + if (!a) + return 0; + + /* Add the entries of a to *k unless they already exist in *r + * in which case they are overridden instead. This assumes + * there is enough space in the r array. */ + + for (; *a; a++) { + char **j; + size_t n; + + n = strcspn(*a, "="); + + if ((*a)[n] == '=') + n++; + + for (j = r; j < *k; j++) + if (strneq(*j, *a, n)) + break; + + if (j >= *k) + (*k)++; + else + free(*j); + + *j = strdup(*a); + if (!*j) + return -ENOMEM; + } + + return 0; +} + +char **strv_env_merge(unsigned n_lists, ...) { + size_t n = 0; + char **l, **k, **r; + va_list ap; + unsigned i; + + /* Merges an arbitrary number of environment sets */ + + va_start(ap, n_lists); + for (i = 0; i < n_lists; i++) { + l = va_arg(ap, char**); + n += strv_length(l); + } + va_end(ap); + + r = new(char*, n+1); + if (!r) + return NULL; + + k = r; + + va_start(ap, n_lists); + for (i = 0; i < n_lists; i++) { + l = va_arg(ap, char**); + if (env_append(r, &k, l) < 0) + goto fail; + } + va_end(ap); + + *k = NULL; + + return r; + +fail: + va_end(ap); + strv_free(r); + + return NULL; +} + +_pure_ static bool env_match(const char *t, const char *pattern) { + assert(t); + assert(pattern); + + /* pattern a matches string a + * a matches a= + * a matches a=b + * a= matches a= + * a=b matches a=b + * a= does not match a + * a=b does not match a= + * a=b does not match a + * a=b does not match a=c */ + + if (streq(t, pattern)) + return true; + + if (!strchr(pattern, '=')) { + size_t l = strlen(pattern); + + return strneq(t, pattern, l) && t[l] == '='; + } + + return false; +} + +char **strv_env_delete(char **x, unsigned n_lists, ...) { + size_t n, i = 0; + char **k, **r; + va_list ap; + + /* Deletes every entry from x that is mentioned in the other + * string lists */ + + n = strv_length(x); + + r = new(char*, n+1); + if (!r) + return NULL; + + STRV_FOREACH(k, x) { + unsigned v; + + va_start(ap, n_lists); + for (v = 0; v < n_lists; v++) { + char **l, **j; + + l = va_arg(ap, char**); + STRV_FOREACH(j, l) + if (env_match(*k, *j)) + goto skip; + } + va_end(ap); + + r[i] = strdup(*k); + if (!r[i]) { + strv_free(r); + return NULL; + } + + i++; + continue; + + skip: + va_end(ap); + } + + r[i] = NULL; + + assert(i <= n); + + return r; +} + +char **strv_env_unset(char **l, const char *p) { + + char **f, **t; + + if (!l) + return NULL; + + assert(p); + + /* Drops every occurrence of the env var setting p in the + * string list. Edits in-place. */ + + for (f = t = l; *f; f++) { + + if (env_match(*f, p)) { + free(*f); + continue; + } + + *(t++) = *f; + } + + *t = NULL; + return l; +} + +char **strv_env_unset_many(char **l, ...) { + + char **f, **t; + + if (!l) + return NULL; + + /* Like strv_env_unset() but applies many at once. Edits in-place. */ + + for (f = t = l; *f; f++) { + bool found = false; + const char *p; + va_list ap; + + va_start(ap, l); + + while ((p = va_arg(ap, const char*))) { + if (env_match(*f, p)) { + found = true; + break; + } + } + + va_end(ap); + + if (found) { + free(*f); + continue; + } + + *(t++) = *f; + } + + *t = NULL; + return l; +} + +char **strv_env_set(char **x, const char *p) { + + char **k, **r; + char* m[2] = { (char*) p, NULL }; + + /* Overrides the env var setting of p, returns a new copy */ + + r = new(char*, strv_length(x)+2); + if (!r) + return NULL; + + k = r; + if (env_append(r, &k, x) < 0) + goto fail; + + if (env_append(r, &k, m) < 0) + goto fail; + + *k = NULL; + + return r; + +fail: + strv_free(r); + return NULL; +} + +char *strv_env_get_n(char **l, const char *name, size_t k) { + char **i; + + assert(name); + + if (k <= 0) + return NULL; + + STRV_FOREACH(i, l) + if (strneq(*i, name, k) && + (*i)[k] == '=') + return *i + k + 1; + + return NULL; +} + +char *strv_env_get(char **l, const char *name) { + assert(name); + + return strv_env_get_n(l, name, strlen(name)); +} + +char **strv_env_clean_with_callback(char **e, void (*invalid_callback)(const char *p, void *userdata), void *userdata) { + char **p, **q; + int k = 0; + + STRV_FOREACH(p, e) { + size_t n; + bool duplicate = false; + + if (!env_assignment_is_valid(*p)) { + if (invalid_callback) + invalid_callback(*p, userdata); + free(*p); + continue; + } + + n = strcspn(*p, "="); + STRV_FOREACH(q, p + 1) + if (strneq(*p, *q, n) && (*q)[n] == '=') { + duplicate = true; + break; + } + + if (duplicate) { + free(*p); + continue; + } + + e[k++] = *p; + } + + if (e) + e[k] = NULL; + + return e; +} + +char *replace_env(const char *format, char **env) { + enum { + WORD, + CURLY, + VARIABLE + } state = WORD; + + const char *e, *word = format; + char *r = NULL, *k; + + assert(format); + + for (e = format; *e; e ++) { + + switch (state) { + + case WORD: + if (*e == '$') + state = CURLY; + break; + + case CURLY: + if (*e == '{') { + k = strnappend(r, word, e-word-1); + if (!k) + goto fail; + + free(r); + r = k; + + word = e-1; + state = VARIABLE; + + } else if (*e == '$') { + k = strnappend(r, word, e-word); + if (!k) + goto fail; + + free(r); + r = k; + + word = e+1; + state = WORD; + } else + state = WORD; + break; + + case VARIABLE: + if (*e == '}') { + const char *t; + + t = strempty(strv_env_get_n(env, word+2, e-word-2)); + + k = strappend(r, t); + if (!k) + goto fail; + + free(r); + r = k; + + word = e+1; + state = WORD; + } + break; + } + } + + k = strnappend(r, word, e-word); + if (!k) + goto fail; + + free(r); + return k; + +fail: + free(r); + return NULL; +} + +char **replace_env_argv(char **argv, char **env) { + char **ret, **i; + unsigned k = 0, l = 0; + + l = strv_length(argv); + + ret = new(char*, l+1); + if (!ret) + return NULL; + + STRV_FOREACH(i, argv) { + + /* If $FOO appears as single word, replace it by the split up variable */ + if ((*i)[0] == '$' && (*i)[1] != '{' && (*i)[1] != '$') { + char *e; + char **w, **m = NULL; + unsigned q; + + e = strv_env_get(env, *i+1); + if (e) { + int r; + + r = strv_split_extract(&m, e, WHITESPACE, EXTRACT_RELAX|EXTRACT_QUOTES); + if (r < 0) { + ret[k] = NULL; + strv_free(ret); + return NULL; + } + } else + m = NULL; + + q = strv_length(m); + l = l + q - 1; + + w = realloc(ret, sizeof(char*) * (l+1)); + if (!w) { + ret[k] = NULL; + strv_free(ret); + strv_free(m); + return NULL; + } + + ret = w; + if (m) { + memcpy(ret + k, m, q * sizeof(char*)); + free(m); + } + + k += q; + continue; + } + + /* If ${FOO} appears as part of a word, replace it by the variable as-is */ + ret[k] = replace_env(*i, env); + if (!ret[k]) { + strv_free(ret); + return NULL; + } + k++; + } + + ret[k] = NULL; + return ret; +} + +int getenv_bool(const char *p) { + const char *e; + + e = getenv(p); + if (!e) + return -ENXIO; + + return parse_boolean(e); +} |