]> git.kernelconcepts.de Git - karo-tx-uboot.git/blobdiff - lib/hashtable.c
env: Add support for callbacks to environment vars
[karo-tx-uboot.git] / lib / hashtable.c
index 670a704a4182947d0fccf8592b372d42b61c62a2..e9226665f3454d8f1f5db60fd5e88bf6bf0c9a10 100644 (file)
@@ -54,7 +54,8 @@
 #define        CONFIG_ENV_MAX_ENTRIES 512
 #endif
 
-#include "search.h"
+#include <env_callback.h>
+#include <search.h>
 
 /*
  * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
  * Instead the interface of all functions is extended to take an argument
  * which describes the current status.
  */
+
 typedef struct _ENTRY {
        int used;
        ENTRY entry;
 } _ENTRY;
 
 
+static void _hdelete(const char *key, struct hsearch_data *htab, ENTRY *ep,
+       int idx);
+
 /*
  * hcreate()
  */
@@ -142,7 +147,7 @@ int hcreate_r(size_t nel, struct hsearch_data *htab)
  * be freed and the local static variable can be marked as not used.
  */
 
-void hdestroy_r(struct hsearch_data *htab, int do_apply)
+void hdestroy_r(struct hsearch_data *htab)
 {
        int i;
 
@@ -156,10 +161,7 @@ void hdestroy_r(struct hsearch_data *htab, int do_apply)
        for (i = 1; i <= htab->size; ++i) {
                if (htab->table[i].used > 0) {
                        ENTRY *ep = &htab->table[i].entry;
-                       if (do_apply && htab->apply != NULL) {
-                               /* deletion is always forced */
-                               htab->apply(ep->key, ep->data, NULL, H_FORCE);
-                       }
+
                        free((void *)ep->key);
                        free(ep->data);
                }
@@ -250,14 +252,65 @@ int hmatch_r(const char *match, int last_idx, ENTRY ** retval,
        return 0;
 }
 
+/*
+ * Compare an existing entry with the desired key, and overwrite if the action
+ * is ENTER.  This is simply a helper function for hsearch_r().
+ */
+static inline int _compare_and_overwrite_entry(ENTRY item, ACTION action,
+       ENTRY **retval, struct hsearch_data *htab, int flag,
+       unsigned int hval, unsigned int idx)
+{
+       if (htab->table[idx].used == hval
+           && strcmp(item.key, htab->table[idx].entry.key) == 0) {
+               /* Overwrite existing value? */
+               if ((action == ENTER) && (item.data != NULL)) {
+                       /* check for permission */
+                       if (htab->change_ok != NULL && htab->change_ok(
+                           &htab->table[idx].entry, item.data,
+                           env_op_overwrite, flag)) {
+                               debug("change_ok() rejected setting variable "
+                                       "%s, skipping it!\n", item.key);
+                               __set_errno(EPERM);
+                               *retval = NULL;
+                               return 0;
+                       }
+
+                       /* If there is a callback, call it */
+                       if (htab->table[idx].entry.callback &&
+                           htab->table[idx].entry.callback(item.key,
+                           item.data, env_op_overwrite, flag)) {
+                               debug("callback() rejected setting variable "
+                                       "%s, skipping it!\n", item.key);
+                               __set_errno(EINVAL);
+                               *retval = NULL;
+                               return 0;
+                       }
+
+                       free(htab->table[idx].entry.data);
+                       htab->table[idx].entry.data = strdup(item.data);
+                       if (!htab->table[idx].entry.data) {
+                               __set_errno(ENOMEM);
+                               *retval = NULL;
+                               return 0;
+                       }
+               }
+               /* return found entry */
+               *retval = &htab->table[idx].entry;
+               return idx;
+       }
+       /* keep searching */
+       return -1;
+}
+
 int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
-             struct hsearch_data *htab)
+             struct hsearch_data *htab, int flag)
 {
        unsigned int hval;
        unsigned int count;
        unsigned int len = strlen(item.key);
        unsigned int idx;
        unsigned int first_deleted = 0;
+       int ret;
 
        /* Compute an value for the given string. Perhaps use a better method. */
        hval = len;
@@ -289,23 +342,10 @@ int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
                    && !first_deleted)
                        first_deleted = idx;
 
-               if (htab->table[idx].used == hval
-                   && strcmp(item.key, htab->table[idx].entry.key) == 0) {
-                       /* Overwrite existing value? */
-                       if ((action == ENTER) && (item.data != NULL)) {
-                               free(htab->table[idx].entry.data);
-                               htab->table[idx].entry.data =
-                                       strdup(item.data);
-                               if (!htab->table[idx].entry.data) {
-                                       __set_errno(ENOMEM);
-                                       *retval = NULL;
-                                       return 0;
-                               }
-                       }
-                       /* return found entry */
-                       *retval = &htab->table[idx].entry;
-                       return idx;
-               }
+               ret = _compare_and_overwrite_entry(item, action, retval, htab,
+                       flag, hval, idx);
+               if (ret != -1)
+                       return ret;
 
                /*
                 * Second hash function:
@@ -331,23 +371,10 @@ int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
                                break;
 
                        /* If entry is found use it. */
-                       if ((htab->table[idx].used == hval)
-                           && strcmp(item.key, htab->table[idx].entry.key) == 0) {
-                               /* Overwrite existing value? */
-                               if ((action == ENTER) && (item.data != NULL)) {
-                                       free(htab->table[idx].entry.data);
-                                       htab->table[idx].entry.data =
-                                               strdup(item.data);
-                                       if (!htab->table[idx].entry.data) {
-                                               __set_errno(ENOMEM);
-                                               *retval = NULL;
-                                               return 0;
-                                       }
-                               }
-                               /* return found entry */
-                               *retval = &htab->table[idx].entry;
-                               return idx;
-                       }
+                       ret = _compare_and_overwrite_entry(item, action, retval,
+                               htab, flag, hval, idx);
+                       if (ret != -1)
+                               return ret;
                }
                while (htab->table[idx].used);
        }
@@ -383,6 +410,32 @@ int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
 
                ++htab->filled;
 
+               /* This is a new entry, so look up a possible callback */
+               env_callback_init(&htab->table[idx].entry);
+
+               /* check for permission */
+               if (htab->change_ok != NULL && htab->change_ok(
+                   &htab->table[idx].entry, item.data, env_op_create, flag)) {
+                       debug("change_ok() rejected setting variable "
+                               "%s, skipping it!\n", item.key);
+                       _hdelete(item.key, htab, &htab->table[idx].entry, idx);
+                       __set_errno(EPERM);
+                       *retval = NULL;
+                       return 0;
+               }
+
+               /* If there is a callback, call it */
+               if (htab->table[idx].entry.callback &&
+                   htab->table[idx].entry.callback(item.key, item.data,
+                   env_op_create, flag)) {
+                       debug("callback() rejected setting variable "
+                               "%s, skipping it!\n", item.key);
+                       _hdelete(item.key, htab, &htab->table[idx].entry, idx);
+                       __set_errno(EINVAL);
+                       *retval = NULL;
+                       return 0;
+               }
+
                /* return new entry */
                *retval = &htab->table[idx].entry;
                return 1;
@@ -404,7 +457,20 @@ int hsearch_r(ENTRY item, ACTION action, ENTRY ** retval,
  * do that.
  */
 
-int hdelete_r(const char *key, struct hsearch_data *htab, int do_apply)
+static void _hdelete(const char *key, struct hsearch_data *htab, ENTRY *ep,
+       int idx)
+{
+       /* free used ENTRY */
+       debug("hdelete: DELETING key \"%s\"\n", key);
+       free((void *)ep->key);
+       free(ep->data);
+       ep->callback = NULL;
+       htab->table[idx].used = -1;
+
+       --htab->filled;
+}
+
+int hdelete_r(const char *key, struct hsearch_data *htab, int flag)
 {
        ENTRY e, *ep;
        int idx;
@@ -413,20 +479,31 @@ int hdelete_r(const char *key, struct hsearch_data *htab, int do_apply)
 
        e.key = (char *)key;
 
-       if ((idx = hsearch_r(e, FIND, &ep, htab)) == 0) {
+       idx = hsearch_r(e, FIND, &ep, htab, 0);
+       if (idx == 0) {
                __set_errno(ESRCH);
                return 0;       /* not found */
        }
 
-       /* free used ENTRY */
-       debug("hdelete: DELETING key \"%s\"\n", key);
-       if (do_apply && htab->apply != NULL)
-               htab->apply(ep->key, ep->data, NULL, H_FORCE);
-       free((void *)ep->key);
-       free(ep->data);
-       htab->table[idx].used = -1;
+       /* Check for permission */
+       if (htab->change_ok != NULL &&
+           htab->change_ok(ep, NULL, env_op_delete, flag)) {
+               debug("change_ok() rejected deleting variable "
+                       "%s, skipping it!\n", key);
+               __set_errno(EPERM);
+               return 0;
+       }
 
-       --htab->filled;
+       /* If there is a callback, call it */
+       if (htab->table[idx].entry.callback &&
+           htab->table[idx].entry.callback(key, NULL, env_op_delete, flag)) {
+               debug("callback() rejected deleting variable "
+                       "%s, skipping it!\n", key);
+               __set_errno(EINVAL);
+               return 0;
+       }
+
+       _hdelete(key, htab, ep, idx);
 
        return 1;
 }
@@ -435,6 +512,7 @@ int hdelete_r(const char *key, struct hsearch_data *htab, int do_apply)
  * hexport()
  */
 
+#ifndef CONFIG_SPL_BUILD
 /*
  * Export the data stored in the hash table in linearized form.
  *
@@ -481,7 +559,7 @@ static int cmpkey(const void *p1, const void *p2)
        return (strcmp(e1->key, e2->key));
 }
 
-ssize_t hexport_r(struct hsearch_data *htab, const char sep,
+ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
                 char **resp, size_t size,
                 int argc, char * const argv[])
 {
@@ -518,6 +596,9 @@ ssize_t hexport_r(struct hsearch_data *htab, const char sep,
                        if ((argc > 0) && (found == 0))
                                continue;
 
+                       if ((flag & H_HIDE_DOT) && ep->key[0] == '.')
+                               continue;
+
                        list[n++] = ep;
 
                        totlen += strlen(ep->key) + 2;
@@ -601,6 +682,7 @@ ssize_t hexport_r(struct hsearch_data *htab, const char sep,
 
        return size;
 }
+#endif
 
 
 /*
@@ -672,7 +754,7 @@ static int drop_var_from_set(const char *name, int nvars, char * vars[])
 
 int himport_r(struct hsearch_data *htab,
                const char *env, size_t size, const char sep, int flag,
-               int nvars, char * const vars[], int do_apply)
+               int nvars, char * const vars[])
 {
        char *data, *sp, *dp, *name, *value;
        char *localvars[nvars];
@@ -702,7 +784,7 @@ int himport_r(struct hsearch_data *htab,
                debug("Destroy Hash Table: %p table = %p\n", htab,
                       htab->table);
                if (htab->table)
-                       hdestroy_r(htab, do_apply);
+                       hdestroy_r(htab);
        }
 
        /*
@@ -768,7 +850,7 @@ int himport_r(struct hsearch_data *htab,
                        if (!drop_var_from_set(name, nvars, localvars))
                                continue;
 
-                       if (hdelete_r(name, htab, do_apply) == 0)
+                       if (hdelete_r(name, htab, flag) == 0)
                                debug("DELETE ERROR ##############################\n");
 
                        continue;
@@ -792,30 +874,10 @@ int himport_r(struct hsearch_data *htab,
                e.key = name;
                e.data = value;
 
-               /* if there is an apply function, check what it has to say */
-               if (do_apply && htab->apply != NULL) {
-                       debug("searching before calling cb function"
-                               " for  %s\n", name);
-                       /*
-                        * Search for variable in existing env, so to pass
-                        * its previous value to the apply callback
-                        */
-                       hsearch_r(e, FIND, &rv, htab);
-                       debug("previous value was %s\n", rv ? rv->data : "");
-                       if (htab->apply(name, rv ? rv->data : NULL,
-                               value, flag)) {
-                               debug("callback function refused to set"
-                                       " variable %s, skipping it!\n", name);
-                               continue;
-                       }
-               }
-
-               hsearch_r(e, ENTER, &rv, htab);
-               if (rv == NULL) {
+               hsearch_r(e, ENTER, &rv, htab, flag);
+               if (rv == NULL)
                        printf("himport_r: can't insert \"%s=%s\" into hash table\n",
                                name, value);
-                       return 0;
-               }
 
                debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
                        htab, htab->filled, htab->size,
@@ -837,7 +899,7 @@ int himport_r(struct hsearch_data *htab,
                 * b) if the variable was not present in current env, we notify
                 *    it might be a typo
                 */
-               if (hdelete_r(localvars[i], htab, do_apply) == 0)
+               if (hdelete_r(localvars[i], htab, flag) == 0)
                        printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]);
                else
                        printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]);
@@ -846,3 +908,27 @@ int himport_r(struct hsearch_data *htab,
        debug("INSERT: done\n");
        return 1;               /* everything OK */
 }
+
+/*
+ * hwalk_r()
+ */
+
+/*
+ * Walk all of the entries in the hash, calling the callback for each one.
+ * this allows some generic operation to be performed on each element.
+ */
+int hwalk_r(struct hsearch_data *htab, int (*callback)(ENTRY *))
+{
+       int i;
+       int retval;
+
+       for (i = 1; i <= htab->size; ++i) {
+               if (htab->table[i].used > 0) {
+                       retval = callback(&htab->table[i].entry);
+                       if (retval)
+                               return retval;
+               }
+       }
+
+       return 0;
+}