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-rw-r--r--libc/stdlib/setenv.c225
1 files changed, 105 insertions, 120 deletions
diff --git a/libc/stdlib/setenv.c b/libc/stdlib/setenv.c
index cf10804ec..6598a6c52 100644
--- a/libc/stdlib/setenv.c
+++ b/libc/stdlib/setenv.c
@@ -46,116 +46,109 @@ static char **last_environ;
is then placed in the environment, while the argument of `putenv'
must be used directly. This is all complicated by the fact that we try
to reuse values once generated for a `setenv' call since we can never
- free the strings. */
-int __add_to_environ (const char *name, const char *value,
- const char *combined, int replace) attribute_hidden;
-int __add_to_environ (const char *name, const char *value,
- const char *combined, int replace)
+ free the strings. [in uclibc, we do not] */
+static int __add_to_environ(const char *name, const char *value,
+ int replace)
{
- register char **ep;
- register size_t size;
- const size_t namelen = strlen (name);
- const size_t vallen = value != NULL ? strlen (value) + 1 : 0;
- int rv = -1;
-
- __UCLIBC_MUTEX_LOCK(mylock);
-
- /* We have to get the pointer now that we have the lock and not earlier
- since another thread might have created a new environment. */
- ep = __environ;
-
- size = 0;
- if (ep != NULL) {
- for (; *ep != NULL; ++ep) {
- if (!strncmp (*ep, name, namelen) && (*ep)[namelen] == '=')
- break;
- else
- ++size;
- }
- }
-
- if (ep == NULL || *ep == NULL) {
- char **new_environ;
-
- /* We allocated this space; we can extend it. */
- new_environ = (char **) realloc (last_environ, (size + 2) * sizeof (char *));
- if (new_environ == NULL) {
- goto DONE;
- }
-
- /* If the whole entry is given add it. */
- if (combined != NULL) {
- /* We must not add the string to the search tree since it belongs
- to the user. */
- new_environ[size] = (char *) combined;
- } else {
- /* See whether the value is already known. */
- new_environ[size] = (char *) malloc (namelen + 1 + vallen);
- if (new_environ[size] == NULL) {
- __set_errno (ENOMEM);
- goto DONE;
+ register char **ep;
+ register size_t size;
+ char *var_val;
+ char **new_environ;
+ /* name may come from putenv() and thus may contain "=VAL" part */
+ const size_t namelen = strchrnul(name, '=') - name;
+ int rv = -1;
+
+ __UCLIBC_MUTEX_LOCK(mylock);
+
+ /* We have to get the pointer now that we have the lock and not earlier
+ since another thread might have created a new environment. */
+ ep = __environ;
+
+ size = 0;
+ if (ep != NULL) {
+ while (*ep != NULL) {
+ if (!strncmp(*ep, name, namelen) && (*ep)[namelen] == '=') {
+ /* Found */
+ if (!replace)
+ goto DONE_OK;
+ goto REPLACE;
}
-
- memcpy (new_environ[size], name, namelen);
- new_environ[size][namelen] = '=';
- memcpy (&new_environ[size][namelen + 1], value, vallen);
- }
-
- if (__environ != last_environ) {
- memcpy ((char *) new_environ, (char *) __environ,
- size * sizeof (char *));
+ ++size;
+ ++ep;
}
-
- new_environ[size + 1] = NULL;
- last_environ = __environ = new_environ;
- } else if (replace) {
- char *np;
-
- /* Use the user string if given. */
- if (combined != NULL) {
- np = (char *) combined;
- } else {
- np = malloc (namelen + 1 + vallen);
- if (np == NULL) {
- goto DONE;
- }
- memcpy (np, name, namelen);
- np[namelen] = '=';
- memcpy (&np[namelen + 1], value, vallen);
+ }
+
+ /* Not found, add at the end */
+
+ /* We allocated this space; we can extend it. */
+ new_environ = realloc(last_environ, (size + 2) * sizeof(char *));
+ if (new_environ == NULL) {
+ __set_errno(ENOMEM);
+ goto DONE;
+ }
+ if (__environ != last_environ) {
+ memcpy(new_environ, __environ, size * sizeof(char *));
+ }
+ last_environ = __environ = new_environ;
+
+ ep = &new_environ[size];
+ /* Ensure env is NULL terminated in case malloc below fails */
+ ep[0] = NULL;
+ ep[1] = NULL;
+
+ REPLACE:
+ var_val = (char*) name;
+ /* Build VAR=VAL if we called by setenv, not putenv. */
+ if (value != NULL) {
+ const size_t vallen = strlen(value) + 1;
+
+ var_val = malloc(namelen + 1 + vallen);
+ if (var_val == NULL) {
+ __set_errno(ENOMEM);
+ goto DONE;
}
- *ep = np;
- }
+ memcpy(var_val, name, namelen);
+ var_val[namelen] = '=';
+ memcpy(&var_val[namelen + 1], value, vallen);
+ }
+ *ep = var_val;
- rv = 0;
+ DONE_OK:
+ rv = 0;
DONE:
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return rv;
+ __UCLIBC_MUTEX_UNLOCK(mylock);
+ return rv;
}
/* libc_hidden_proto(setenv) */
-int setenv (const char *name, const char *value, int replace)
+int setenv(const char *name, const char *value, int replace)
{
- return __add_to_environ (name, value, NULL, replace);
+ /* NB: setenv("VAR", NULL, 1) inserts "VAR=" string */
+ return __add_to_environ(name, value ? value : "", replace);
}
libc_hidden_def(setenv)
/* libc_hidden_proto(unsetenv) */
-int unsetenv (const char *name)
+int unsetenv(const char *name)
{
- size_t len;
- char **ep;
-
- if (name == NULL || *name == '\0' || strchr (name, '=') != NULL) {
- __set_errno (EINVAL);
+ const char *eq;
+ size_t len;
+ char **ep;
+
+ if (name == NULL || *name == '\0'
+ || *(eq = strchrnul(name, '=')) == '='
+ ) {
+ __set_errno(EINVAL);
return -1;
- }
-
- len = strlen (name);
- __UCLIBC_MUTEX_LOCK(mylock);
- ep = __environ;
- while (*ep != NULL) {
- if (!strncmp (*ep, name, len) && (*ep)[len] == '=') {
+ }
+ len = eq - name; /* avoiding strlen this way */
+
+ __UCLIBC_MUTEX_LOCK(mylock);
+ ep = __environ;
+ /* NB: clearenv(); unsetenv("foo"); should not segfault */
+ if (ep) while (*ep != NULL) {
+ if (!strncmp(*ep, name, len) && (*ep)[len] == '=') {
/* Found it. Remove this pointer by moving later ones back. */
char **dp = ep;
do {
@@ -165,42 +158,34 @@ int unsetenv (const char *name)
} else {
++ep;
}
- }
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return 0;
+ }
+ __UCLIBC_MUTEX_UNLOCK(mylock);
+ return 0;
}
libc_hidden_def(unsetenv)
/* The `clearenv' was planned to be added to POSIX.1 but probably
never made it. Nevertheless the POSIX.9 standard (POSIX bindings
for Fortran 77) requires this function. */
-int clearenv (void)
+int clearenv(void)
{
- __UCLIBC_MUTEX_LOCK(mylock);
- if (__environ == last_environ && __environ != NULL) {
- /* We allocated this environment so we can free it. */
- free (__environ);
- last_environ = NULL;
- }
- /* Clear the environment pointer removes the whole environment. */
- __environ = NULL;
- __UCLIBC_MUTEX_UNLOCK(mylock);
- return 0;
+ __UCLIBC_MUTEX_LOCK(mylock);
+ /* If we allocated this environment we can free it.
+ * If we did not allocate this environment, it's NULL already
+ * and is safe to free(). */
+ free(last_environ);
+ last_environ = NULL;
+ /* Clearing environ removes the whole environment. */
+ __environ = NULL;
+ __UCLIBC_MUTEX_UNLOCK(mylock);
+ return 0;
}
/* Put STRING, which is of the form "NAME=VALUE", in the environment. */
-int putenv (char *string)
+int putenv(char *string)
{
- int result;
- const char *const name_end = strchr (string, '=');
-
- if (name_end != NULL) {
- char *name = strndup(string, name_end - string);
- result = __add_to_environ (name, NULL, string, 1);
- free(name);
- return(result);
- }
- unsetenv (string);
- return 0;
+ if (strchr(string, '=') != NULL) {
+ return __add_to_environ(string, NULL, 1);
+ }
+ return unsetenv(string);
}
-
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-10 13:47:07 +0000