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-rw-r--r--tools/env/fw_env.c74
1 files changed, 70 insertions, 4 deletions
diff --git a/tools/env/fw_env.c b/tools/env/fw_env.c
index 5be36fc35..a596a1b0d 100644
--- a/tools/env/fw_env.c
+++ b/tools/env/fw_env.c
@@ -182,6 +182,32 @@ char *fw_getenv (char *name)
}
/*
+ * Search the default environment for a variable.
+ * Return the value, if found, or NULL, if not found.
+ */
+char *fw_getdefenv(char *name)
+{
+ char *env, *nxt;
+
+ for (env = default_environment; *env; env = nxt + 1) {
+ char *val;
+
+ for (nxt = env; *nxt; ++nxt) {
+ if (nxt >= &default_environment[ENV_SIZE]) {
+ fprintf(stderr, "## Error: "
+ "default environment not terminated\n");
+ return NULL;
+ }
+ }
+ val = envmatch(name, env);
+ if (!val)
+ continue;
+ return val;
+ }
+ return NULL;
+}
+
+/*
* Print the current definition of one, or more, or all
* environment variables
*/
@@ -282,6 +308,7 @@ int fw_env_write(char *name, char *value)
int len;
char *env, *nxt;
char *oldval = NULL;
+ int deleting, creating, overwriting;
/*
* search if variable with this name already exists
@@ -299,10 +326,49 @@ int fw_env_write(char *name, char *value)
break;
}
- /*
- * Delete any existing definition
- */
- if (oldval) {
+ deleting = (oldval && !(value && strlen(value)));
+ creating = (!oldval && (value && strlen(value)));
+ overwriting = (oldval && (value && strlen(value)));
+
+ /* check for permission */
+ if (deleting) {
+ if (env_flags_validate_varaccess(name,
+ ENV_FLAGS_VARACCESS_PREVENT_DELETE)) {
+ printf("Can't delete \"%s\"\n", name);
+ errno = EROFS;
+ return -1;
+ }
+ } else if (overwriting) {
+ if (env_flags_validate_varaccess(name,
+ ENV_FLAGS_VARACCESS_PREVENT_OVERWR)) {
+ printf("Can't overwrite \"%s\"\n", name);
+ errno = EROFS;
+ return -1;
+ } else if (env_flags_validate_varaccess(name,
+ ENV_FLAGS_VARACCESS_PREVENT_NONDEF_OVERWR)) {
+ const char *defval = fw_getdefenv(name);
+
+ if (defval == NULL)
+ defval = "";
+ if (strcmp(oldval, defval)
+ != 0) {
+ printf("Can't overwrite \"%s\"\n", name);
+ errno = EROFS;
+ return -1;
+ }
+ }
+ } else if (creating) {
+ if (env_flags_validate_varaccess(name,
+ ENV_FLAGS_VARACCESS_PREVENT_CREATE)) {
+ printf("Can't create \"%s\"\n", name);
+ errno = EROFS;
+ return -1;
+ }
+ } else
+ /* Nothing to do */
+ return 0;
+
+ if (deleting || overwriting) {
#ifndef CONFIG_ENV_OVERWRITE
/*
* Ethernet Address and serial# can be set only once