posix: env: move most implementations to env-common.c

Move most implementations to env-common.c in preparation for adding
putenv.c .

We also take this as an opportunity to switch from using k_spinlock
to sys_sem.

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>

Author: cfriedt

lib/posix/options/CMakeLists.txt

@@ -102,6 +102,7 @@ if (NOT CONFIG_TC_PROVIDES_POSIX_SINGLE_PROCESS)
   zephyr_library_sources_ifdef(CONFIG_POSIX_SINGLE_PROCESS
     confstr.c
     env.c
+    env_common.c
     sysconf.c
     uname.c
   )

lib/posix/options/env.c

@@ -4,279 +4,28 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-#include <errno.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
+#include <stddef.h>
 
-#include <zephyr/logging/log.h>
-#include <zephyr/spinlock.h>
+extern char *z_getenv(const char *name);
+extern int z_getenv_r(const char *name, char *buf, size_t len);
+extern int z_setenv(const char *name, const char *val, int overwrite);
+extern int z_unsetenv(const char *name);
 
-#define TRACK_ALLOC (IS_ENABLED(CONFIG_POSIX_ENV_LOG_LEVEL_DBG) || IS_ENABLED(CONFIG_ZTEST))
-
-LOG_MODULE_REGISTER(posix_env, CONFIG_POSIX_ENV_LOG_LEVEL);
-
-static struct k_spinlock environ_lock;
-static size_t allocated;
-char **environ;
-
-#ifdef CONFIG_ZTEST
-size_t posix_env_get_allocated_space(void)
-{
-	return allocated;
-}
-#endif
-
-static size_t environ_size(void)
-{
-	size_t ret;
-
-	if (environ == NULL) {
-		return 0;
-	}
-
-	for (ret = 0; environ[ret] != NULL; ++ret) {
-	}
-
-	return ret;
-}
-
-static int findenv(const char *name, size_t namelen)
-{
-	const char *env;
-
-	if (name == NULL || namelen == 0 || strchr(name, '=') != NULL) {
-		/* Note: '=' is not a valid name character */
-		return -EINVAL;
-	}
-
-	if (environ == NULL) {
-		return -ENOENT;
-	}
-
-	for (char **envp = &environ[0]; *envp != NULL; ++envp) {
-		env = *envp;
-		if (strncmp(env, name, namelen) == 0 && env[namelen] == '=') {
-			return envp - environ;
-		}
-	}
-
-	return -ENOENT;
-}
-
-char *z_getenv(const char *name)
-{
-	int ret;
-	size_t nsize;
-	char *val = NULL;
-
-	nsize = (name == NULL) ? 0 : strlen(name);
-	K_SPINLOCK(&environ_lock)
-	{
-		ret = findenv(name, nsize);
-		if (ret < 0) {
-			K_SPINLOCK_BREAK;
-		}
-
-		val = environ[ret] + nsize + 1;
-	}
-
-	return val;
-}
 char *getenv(const char *name)
 {
 	return z_getenv(name);
 }
 
-int z_getenv_r(const char *name, char *buf, size_t len)
-{
-	int ret = 0;
-	size_t vsize;
-	size_t nsize;
-	char *val = NULL;
-
-	nsize = (name == NULL) ? 0 : strlen(name);
-	K_SPINLOCK(&environ_lock)
-	{
-		ret = findenv(name, nsize);
-		if (ret < 0) {
-			LOG_DBG("No entry for name '%s'", name);
-			K_SPINLOCK_BREAK;
-		}
-
-		val = environ[ret] + nsize + 1;
-		vsize = strlen(val) + 1;
-		if (vsize > len) {
-			ret = -ERANGE;
-			K_SPINLOCK_BREAK;
-		}
-		strcpy(buf, val);
-		LOG_DBG("Found entry %s", environ[ret]);
-	}
-
-	if (ret < 0) {
-		errno = -ret;
-		ret = -1;
-	}
-
-	return ret;
-}
 int getenv_r(const char *name, char *buf, size_t len)
 {
 	return z_getenv_r(name, buf, len);
 }
 
-int z_setenv(const char *name, const char *val, int overwrite)
-{
-	int ret = 0;
-	char *env;
-	char **envp;
-	size_t esize;
-	const size_t vsize = (val == NULL) ? 0 : strlen(val);
-	const size_t nsize = (name == NULL) ? 0 : strlen(name);
-	/* total size of name + '=' + val + '\0' */
-	const size_t tsize = nsize + 1 /* '=' */ + vsize + 1 /* '\0' */;
-
-	if (name == NULL || val == NULL) {
-		LOG_DBG("Invalid name '%s' or value '%s'", name, val);
-		errno = EINVAL;
-		return -1;
-	}
-
-	K_SPINLOCK(&environ_lock)
-	{
-		ret = findenv(name, nsize);
-		if (ret == -EINVAL) {
-			LOG_DBG("Invalid name '%s'", name);
-			K_SPINLOCK_BREAK;
-		}
-		if (ret >= 0) {
-			/* name was found in environ */
-			esize = strlen(environ[ret]) + 1;
-			if (overwrite == 0) {
-				LOG_DBG("Found entry %s", environ[ret]);
-				ret = 0;
-				K_SPINLOCK_BREAK;
-			}
-		} else {
-			/* name was not found in environ -> add new entry */
-			esize = environ_size();
-			envp = realloc(environ, sizeof(char **) *
-							(esize + 1 /* new entry */ + 1 /* NULL */));
-			if (envp == NULL) {
-				ret = -ENOMEM;
-				K_SPINLOCK_BREAK;
-			}
-
-			if (TRACK_ALLOC) {
-				allocated += sizeof(char **) * (esize + 2);
-				LOG_DBG("realloc %zu bytes (allocated: %zu)",
-					sizeof(char **) * (esize + 2), allocated);
-			}
-
-			environ = envp;
-			ret = esize;
-			environ[ret] = NULL;
-			environ[ret + 1] = NULL;
-			esize = 0;
-		}
-
-		if (esize < tsize) {
-			/* need to malloc or realloc space for new environ entry */
-			env = realloc(environ[ret], tsize);
-			if (env == NULL) {
-				ret = -ENOMEM;
-				K_SPINLOCK_BREAK;
-			}
-			if (TRACK_ALLOC) {
-				allocated += tsize - esize;
-				LOG_DBG("realloc %zu bytes (allocated: %zu)", tsize - esize,
-					allocated);
-			}
-			environ[ret] = env;
-		}
-
-		strcpy(environ[ret], name);
-		environ[ret][nsize] = '=';
-		strncpy(environ[ret] + nsize + 1, val, vsize + 1);
-		LOG_DBG("Added entry %s", environ[ret]);
-
-		ret = 0;
-	}
-
-	if (ret < 0) {
-		errno = -ret;
-		ret = -1;
-	}
-
-	return ret;
-}
 int setenv(const char *name, const char *val, int overwrite)
 {
 	return z_setenv(name, val, overwrite);
 }
 
-int z_unsetenv(const char *name)
-{
-	int ret = 0;
-	char **envp;
-	size_t esize;
-	size_t nsize;
-
-	nsize = (name == NULL) ? 0 : strlen(name);
-	K_SPINLOCK(&environ_lock)
-	{
-		ret = findenv(name, nsize);
-		if (ret < 0) {
-			ret = (ret == -EINVAL) ? -EINVAL : 0;
-			K_SPINLOCK_BREAK;
-		}
-
-		esize = environ_size();
-		if (TRACK_ALLOC) {
-			allocated -= strlen(environ[ret]) + 1;
-			LOG_DBG("free %zu bytes (allocated: %zu)", strlen(environ[ret]) + 1,
-				allocated);
-		}
-		free(environ[ret]);
-
-		/* shuffle remaining environment variable pointers forward */
-		for (; ret < esize; ++ret) {
-			environ[ret] = environ[ret + 1];
-		}
-		/* environ must be terminated with a NULL pointer */
-		environ[ret] = NULL;
-
-		/* reduce environ size and update allocation */
-		--esize;
-		if (esize == 0) {
-			free(environ);
-			environ = NULL;
-		} else {
-			envp = realloc(environ, (esize + 1 /* NULL */) * sizeof(char **));
-			if (envp != NULL) {
-				environ = envp;
-			}
-		}
-		__ASSERT_NO_MSG((esize >= 1 && environ != NULL) || environ == NULL);
-
-		if (TRACK_ALLOC) {
-			/* recycle nsize here */
-			nsize = ((esize == 0) ? 2 : 1) * sizeof(char **);
-			allocated -= nsize;
-			LOG_DBG("free %zu bytes (allocated: %zu)", nsize, allocated);
-		}
-
-		ret = 0;
-	}
-
-	if (ret < 0) {
-		errno = -ret;
-		ret = -1;
-	}
-
-	return ret;
-}
 int unsetenv(const char *name)
 {
 	return z_unsetenv(name);