X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Froms%2Fu-boot%2Flib%2Fhashtable.c;fp=qemu%2Froms%2Fu-boot%2Flib%2Fhashtable.c;h=4356b234ececa2ec586da0198d5306f5de6114f9;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git

diff --git a/qemu/roms/u-boot/lib/hashtable.c b/qemu/roms/u-boot/lib/hashtable.c
new file mode 100644
index 000000000..4356b234e
--- /dev/null
+++ b/qemu/roms/u-boot/lib/hashtable.c
@@ -0,0 +1,962 @@
+/*
+ * This implementation is based on code from uClibc-0.9.30.3 but was
+ * modified and extended for use within U-Boot.
+ *
+ * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de>
+ *
+ * Original license header:
+ *
+ * Copyright (C) 1993, 1995, 1996, 1997, 2002 Free Software Foundation, Inc.
+ * This file is part of the GNU C Library.
+ * Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1993.
+ *
+ * SPDX-License-Identifier:	LGPL-2.1+
+ */
+
+#include <errno.h>
+#include <malloc.h>
+
+#ifdef USE_HOSTCC		/* HOST build */
+# include <string.h>
+# include <assert.h>
+# include <ctype.h>
+
+# ifndef debug
+#  ifdef DEBUG
+#   define debug(fmt,args...)	printf(fmt ,##args)
+#  else
+#   define debug(fmt,args...)
+#  endif
+# endif
+#else				/* U-Boot build */
+# include <common.h>
+# include <linux/string.h>
+# include <linux/ctype.h>
+#endif
+
+#ifndef	CONFIG_ENV_MIN_ENTRIES	/* minimum number of entries */
+#define	CONFIG_ENV_MIN_ENTRIES 64
+#endif
+#ifndef	CONFIG_ENV_MAX_ENTRIES	/* maximum number of entries */
+#define	CONFIG_ENV_MAX_ENTRIES 512
+#endif
+
+#include <env_callback.h>
+#include <env_flags.h>
+#include <search.h>
+#include <slre.h>
+
+/*
+ * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986
+ * [Knuth]	      The Art of Computer Programming, part 3 (6.4)
+ */
+
+/*
+ * The reentrant version has no static variables to maintain the state.
+ * 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()
+ */
+
+/*
+ * For the used double hash method the table size has to be a prime. To
+ * correct the user given table size we need a prime test.  This trivial
+ * algorithm is adequate because
+ * a)  the code is (most probably) called a few times per program run and
+ * b)  the number is small because the table must fit in the core
+ * */
+static int isprime(unsigned int number)
+{
+	/* no even number will be passed */
+	unsigned int div = 3;
+
+	while (div * div < number && number % div != 0)
+		div += 2;
+
+	return number % div != 0;
+}
+
+/*
+ * Before using the hash table we must allocate memory for it.
+ * Test for an existing table are done. We allocate one element
+ * more as the found prime number says. This is done for more effective
+ * indexing as explained in the comment for the hsearch function.
+ * The contents of the table is zeroed, especially the field used
+ * becomes zero.
+ */
+
+int hcreate_r(size_t nel, struct hsearch_data *htab)
+{
+	/* Test for correct arguments.  */
+	if (htab == NULL) {
+		__set_errno(EINVAL);
+		return 0;
+	}
+
+	/* There is still another table active. Return with error. */
+	if (htab->table != NULL)
+		return 0;
+
+	/* Change nel to the first prime number not smaller as nel. */
+	nel |= 1;		/* make odd */
+	while (!isprime(nel))
+		nel += 2;
+
+	htab->size = nel;
+	htab->filled = 0;
+
+	/* allocate memory and zero out */
+	htab->table = (_ENTRY *) calloc(htab->size + 1, sizeof(_ENTRY));
+	if (htab->table == NULL)
+		return 0;
+
+	/* everything went alright */
+	return 1;
+}
+
+
+/*
+ * hdestroy()
+ */
+
+/*
+ * After using the hash table it has to be destroyed. The used memory can
+ * be freed and the local static variable can be marked as not used.
+ */
+
+void hdestroy_r(struct hsearch_data *htab)
+{
+	int i;
+
+	/* Test for correct arguments.  */
+	if (htab == NULL) {
+		__set_errno(EINVAL);
+		return;
+	}
+
+	/* free used memory */
+	for (i = 1; i <= htab->size; ++i) {
+		if (htab->table[i].used > 0) {
+			ENTRY *ep = &htab->table[i].entry;
+
+			free((void *)ep->key);
+			free(ep->data);
+		}
+	}
+	free(htab->table);
+
+	/* the sign for an existing table is an value != NULL in htable */
+	htab->table = NULL;
+}
+
+/*
+ * hsearch()
+ */
+
+/*
+ * This is the search function. It uses double hashing with open addressing.
+ * The argument item.key has to be a pointer to an zero terminated, most
+ * probably strings of chars. The function for generating a number of the
+ * strings is simple but fast. It can be replaced by a more complex function
+ * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown.
+ *
+ * We use an trick to speed up the lookup. The table is created by hcreate
+ * with one more element available. This enables us to use the index zero
+ * special. This index will never be used because we store the first hash
+ * index in the field used where zero means not used. Every other value
+ * means used. The used field can be used as a first fast comparison for
+ * equality of the stored and the parameter value. This helps to prevent
+ * unnecessary expensive calls of strcmp.
+ *
+ * This implementation differs from the standard library version of
+ * this function in a number of ways:
+ *
+ * - While the standard version does not make any assumptions about
+ *   the type of the stored data objects at all, this implementation
+ *   works with NUL terminated strings only.
+ * - Instead of storing just pointers to the original objects, we
+ *   create local copies so the caller does not need to care about the
+ *   data any more.
+ * - The standard implementation does not provide a way to update an
+ *   existing entry.  This version will create a new entry or update an
+ *   existing one when both "action == ENTER" and "item.data != NULL".
+ * - Instead of returning 1 on success, we return the index into the
+ *   internal hash table, which is also guaranteed to be positive.
+ *   This allows us direct access to the found hash table slot for
+ *   example for functions like hdelete().
+ */
+
+int hmatch_r(const char *match, int last_idx, ENTRY ** retval,
+	     struct hsearch_data *htab)
+{
+	unsigned int idx;
+	size_t key_len = strlen(match);
+
+	for (idx = last_idx + 1; idx < htab->size; ++idx) {
+		if (htab->table[idx].used <= 0)
+			continue;
+		if (!strncmp(match, htab->table[idx].entry.key, key_len)) {
+			*retval = &htab->table[idx].entry;
+			return idx;
+		}
+	}
+
+	__set_errno(ESRCH);
+	*retval = NULL;
+	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, 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;
+	count = len;
+	while (count-- > 0) {
+		hval <<= 4;
+		hval += item.key[count];
+	}
+
+	/*
+	 * First hash function:
+	 * simply take the modul but prevent zero.
+	 */
+	hval %= htab->size;
+	if (hval == 0)
+		++hval;
+
+	/* The first index tried. */
+	idx = hval;
+
+	if (htab->table[idx].used) {
+		/*
+		 * Further action might be required according to the
+		 * action value.
+		 */
+		unsigned hval2;
+
+		if (htab->table[idx].used == -1
+		    && !first_deleted)
+			first_deleted = idx;
+
+		ret = _compare_and_overwrite_entry(item, action, retval, htab,
+			flag, hval, idx);
+		if (ret != -1)
+			return ret;
+
+		/*
+		 * Second hash function:
+		 * as suggested in [Knuth]
+		 */
+		hval2 = 1 + hval % (htab->size - 2);
+
+		do {
+			/*
+			 * Because SIZE is prime this guarantees to
+			 * step through all available indices.
+			 */
+			if (idx <= hval2)
+				idx = htab->size + idx - hval2;
+			else
+				idx -= hval2;
+
+			/*
+			 * If we visited all entries leave the loop
+			 * unsuccessfully.
+			 */
+			if (idx == hval)
+				break;
+
+			/* If entry is found use it. */
+			ret = _compare_and_overwrite_entry(item, action, retval,
+				htab, flag, hval, idx);
+			if (ret != -1)
+				return ret;
+		}
+		while (htab->table[idx].used);
+	}
+
+	/* An empty bucket has been found. */
+	if (action == ENTER) {
+		/*
+		 * If table is full and another entry should be
+		 * entered return with error.
+		 */
+		if (htab->filled == htab->size) {
+			__set_errno(ENOMEM);
+			*retval = NULL;
+			return 0;
+		}
+
+		/*
+		 * Create new entry;
+		 * create copies of item.key and item.data
+		 */
+		if (first_deleted)
+			idx = first_deleted;
+
+		htab->table[idx].used = hval;
+		htab->table[idx].entry.key = strdup(item.key);
+		htab->table[idx].entry.data = strdup(item.data);
+		if (!htab->table[idx].entry.key ||
+		    !htab->table[idx].entry.data) {
+			__set_errno(ENOMEM);
+			*retval = NULL;
+			return 0;
+		}
+
+		++htab->filled;
+
+		/* This is a new entry, so look up a possible callback */
+		env_callback_init(&htab->table[idx].entry);
+		/* Also look for flags */
+		env_flags_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;
+	}
+
+	__set_errno(ESRCH);
+	*retval = NULL;
+	return 0;
+}
+
+
+/*
+ * hdelete()
+ */
+
+/*
+ * The standard implementation of hsearch(3) does not provide any way
+ * to delete any entries from the hash table.  We extend the code to
+ * do that.
+ */
+
+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;
+	ep->flags = 0;
+	htab->table[idx].used = -1;
+
+	--htab->filled;
+}
+
+int hdelete_r(const char *key, struct hsearch_data *htab, int flag)
+{
+	ENTRY e, *ep;
+	int idx;
+
+	debug("hdelete: DELETE key \"%s\"\n", key);
+
+	e.key = (char *)key;
+
+	idx = hsearch_r(e, FIND, &ep, htab, 0);
+	if (idx == 0) {
+		__set_errno(ESRCH);
+		return 0;	/* not found */
+	}
+
+	/* 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;
+	}
+
+	/* 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;
+}
+
+/*
+ * hexport()
+ */
+
+#ifndef CONFIG_SPL_BUILD
+/*
+ * Export the data stored in the hash table in linearized form.
+ *
+ * Entries are exported as "name=value" strings, separated by an
+ * arbitrary (non-NUL, of course) separator character. This allows to
+ * use this function both when formatting the U-Boot environment for
+ * external storage (using '\0' as separator), but also when using it
+ * for the "printenv" command to print all variables, simply by using
+ * as '\n" as separator. This can also be used for new features like
+ * exporting the environment data as text file, including the option
+ * for later re-import.
+ *
+ * The entries in the result list will be sorted by ascending key
+ * values.
+ *
+ * If the separator character is different from NUL, then any
+ * separator characters and backslash characters in the values will
+ * be escaped by a preceeding backslash in output. This is needed for
+ * example to enable multi-line values, especially when the output
+ * shall later be parsed (for example, for re-import).
+ *
+ * There are several options how the result buffer is handled:
+ *
+ * *resp  size
+ * -----------
+ *  NULL    0	A string of sufficient length will be allocated.
+ *  NULL   >0	A string of the size given will be
+ *		allocated. An error will be returned if the size is
+ *		not sufficient.  Any unused bytes in the string will
+ *		be '\0'-padded.
+ * !NULL    0	The user-supplied buffer will be used. No length
+ *		checking will be performed, i. e. it is assumed that
+ *		the buffer size will always be big enough. DANGEROUS.
+ * !NULL   >0	The user-supplied buffer will be used. An error will
+ *		be returned if the size is not sufficient.  Any unused
+ *		bytes in the string will be '\0'-padded.
+ */
+
+static int cmpkey(const void *p1, const void *p2)
+{
+	ENTRY *e1 = *(ENTRY **) p1;
+	ENTRY *e2 = *(ENTRY **) p2;
+
+	return (strcmp(e1->key, e2->key));
+}
+
+static int match_string(int flag, const char *str, const char *pat, void *priv)
+{
+	switch (flag & H_MATCH_METHOD) {
+	case H_MATCH_IDENT:
+		if (strcmp(str, pat) == 0)
+			return 1;
+		break;
+	case H_MATCH_SUBSTR:
+		if (strstr(str, pat))
+			return 1;
+		break;
+#ifdef CONFIG_REGEX
+	case H_MATCH_REGEX:
+		{
+			struct slre *slrep = (struct slre *)priv;
+			struct cap caps[slrep->num_caps + 2];
+
+			if (slre_match(slrep, str, strlen(str), caps))
+				return 1;
+		}
+		break;
+#endif
+	default:
+		printf("## ERROR: unsupported match method: 0x%02x\n",
+			flag & H_MATCH_METHOD);
+		break;
+	}
+	return 0;
+}
+
+static int match_entry(ENTRY *ep, int flag,
+		 int argc, char * const argv[])
+{
+	int arg;
+	void *priv = NULL;
+
+	for (arg = 0; arg < argc; ++arg) {
+#ifdef CONFIG_REGEX
+		struct slre slre;
+
+		if (slre_compile(&slre, argv[arg]) == 0) {
+			printf("Error compiling regex: %s\n", slre.err_str);
+			return 0;
+		}
+
+		priv = (void *)&slre;
+#endif
+		if (flag & H_MATCH_KEY) {
+			if (match_string(flag, ep->key, argv[arg], priv))
+				return 1;
+		}
+		if (flag & H_MATCH_DATA) {
+			if (match_string(flag, ep->data, argv[arg], priv))
+				return 1;
+		}
+	}
+	return 0;
+}
+
+ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag,
+		 char **resp, size_t size,
+		 int argc, char * const argv[])
+{
+	ENTRY *list[htab->size];
+	char *res, *p;
+	size_t totlen;
+	int i, n;
+
+	/* Test for correct arguments.  */
+	if ((resp == NULL) || (htab == NULL)) {
+		__set_errno(EINVAL);
+		return (-1);
+	}
+
+	debug("EXPORT  table = %p, htab.size = %d, htab.filled = %d, "
+		"size = %zu\n", htab, htab->size, htab->filled, size);
+	/*
+	 * Pass 1:
+	 * search used entries,
+	 * save addresses and compute total length
+	 */
+	for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) {
+
+		if (htab->table[i].used > 0) {
+			ENTRY *ep = &htab->table[i].entry;
+			int found = match_entry(ep, flag, argc, argv);
+
+			if ((argc > 0) && (found == 0))
+				continue;
+
+			if ((flag & H_HIDE_DOT) && ep->key[0] == '.')
+				continue;
+
+			list[n++] = ep;
+
+			totlen += strlen(ep->key) + 2;
+
+			if (sep == '\0') {
+				totlen += strlen(ep->data);
+			} else {	/* check if escapes are needed */
+				char *s = ep->data;
+
+				while (*s) {
+					++totlen;
+					/* add room for needed escape chars */
+					if ((*s == sep) || (*s == '\\'))
+						++totlen;
+					++s;
+				}
+			}
+			totlen += 2;	/* for '=' and 'sep' char */
+		}
+	}
+
+#ifdef DEBUG
+	/* Pass 1a: print unsorted list */
+	printf("Unsorted: n=%d\n", n);
+	for (i = 0; i < n; ++i) {
+		printf("\t%3d: %p ==> %-10s => %s\n",
+		       i, list[i], list[i]->key, list[i]->data);
+	}
+#endif
+
+	/* Sort list by keys */
+	qsort(list, n, sizeof(ENTRY *), cmpkey);
+
+	/* Check if the user supplied buffer size is sufficient */
+	if (size) {
+		if (size < totlen + 1) {	/* provided buffer too small */
+			printf("Env export buffer too small: %zu, "
+				"but need %zu\n", size, totlen + 1);
+			__set_errno(ENOMEM);
+			return (-1);
+		}
+	} else {
+		size = totlen + 1;
+	}
+
+	/* Check if the user provided a buffer */
+	if (*resp) {
+		/* yes; clear it */
+		res = *resp;
+		memset(res, '\0', size);
+	} else {
+		/* no, allocate and clear one */
+		*resp = res = calloc(1, size);
+		if (res == NULL) {
+			__set_errno(ENOMEM);
+			return (-1);
+		}
+	}
+	/*
+	 * Pass 2:
+	 * export sorted list of result data
+	 */
+	for (i = 0, p = res; i < n; ++i) {
+		const char *s;
+
+		s = list[i]->key;
+		while (*s)
+			*p++ = *s++;
+		*p++ = '=';
+
+		s = list[i]->data;
+
+		while (*s) {
+			if ((*s == sep) || (*s == '\\'))
+				*p++ = '\\';	/* escape */
+			*p++ = *s++;
+		}
+		*p++ = sep;
+	}
+	*p = '\0';		/* terminate result */
+
+	return size;
+}
+#endif
+
+
+/*
+ * himport()
+ */
+
+/*
+ * Check whether variable 'name' is amongst vars[],
+ * and remove all instances by setting the pointer to NULL
+ */
+static int drop_var_from_set(const char *name, int nvars, char * vars[])
+{
+	int i = 0;
+	int res = 0;
+
+	/* No variables specified means process all of them */
+	if (nvars == 0)
+		return 1;
+
+	for (i = 0; i < nvars; i++) {
+		if (vars[i] == NULL)
+			continue;
+		/* If we found it, delete all of them */
+		if (!strcmp(name, vars[i])) {
+			vars[i] = NULL;
+			res = 1;
+		}
+	}
+	if (!res)
+		debug("Skipping non-listed variable %s\n", name);
+
+	return res;
+}
+
+/*
+ * Import linearized data into hash table.
+ *
+ * This is the inverse function to hexport(): it takes a linear list
+ * of "name=value" pairs and creates hash table entries from it.
+ *
+ * Entries without "value", i. e. consisting of only "name" or
+ * "name=", will cause this entry to be deleted from the hash table.
+ *
+ * The "flag" argument can be used to control the behaviour: when the
+ * H_NOCLEAR bit is set, then an existing hash table will kept, i. e.
+ * new data will be added to an existing hash table; otherwise, old
+ * data will be discarded and a new hash table will be created.
+ *
+ * The separator character for the "name=value" pairs can be selected,
+ * so we both support importing from externally stored environment
+ * data (separated by NUL characters) and from plain text files
+ * (entries separated by newline characters).
+ *
+ * To allow for nicely formatted text input, leading white space
+ * (sequences of SPACE and TAB chars) is ignored, and entries starting
+ * (after removal of any leading white space) with a '#' character are
+ * considered comments and ignored.
+ *
+ * [NOTE: this means that a variable name cannot start with a '#'
+ * character.]
+ *
+ * When using a non-NUL separator character, backslash is used as
+ * escape character in the value part, allowing for example for
+ * multi-line values.
+ *
+ * In theory, arbitrary separator characters can be used, but only
+ * '\0' and '\n' have really been tested.
+ */
+
+int himport_r(struct hsearch_data *htab,
+		const char *env, size_t size, const char sep, int flag,
+		int nvars, char * const vars[])
+{
+	char *data, *sp, *dp, *name, *value;
+	char *localvars[nvars];
+	int i;
+
+	/* Test for correct arguments.  */
+	if (htab == NULL) {
+		__set_errno(EINVAL);
+		return 0;
+	}
+
+	/* we allocate new space to make sure we can write to the array */
+	if ((data = malloc(size)) == NULL) {
+		debug("himport_r: can't malloc %zu bytes\n", size);
+		__set_errno(ENOMEM);
+		return 0;
+	}
+	memcpy(data, env, size);
+	dp = data;
+
+	/* make a local copy of the list of variables */
+	if (nvars)
+		memcpy(localvars, vars, sizeof(vars[0]) * nvars);
+
+	if ((flag & H_NOCLEAR) == 0) {
+		/* Destroy old hash table if one exists */
+		debug("Destroy Hash Table: %p table = %p\n", htab,
+		       htab->table);
+		if (htab->table)
+			hdestroy_r(htab);
+	}
+
+	/*
+	 * Create new hash table (if needed).  The computation of the hash
+	 * table size is based on heuristics: in a sample of some 70+
+	 * existing systems we found an average size of 39+ bytes per entry
+	 * in the environment (for the whole key=value pair). Assuming a
+	 * size of 8 per entry (= safety factor of ~5) should provide enough
+	 * safety margin for any existing environment definitions and still
+	 * allow for more than enough dynamic additions. Note that the
+	 * "size" argument is supposed to give the maximum environment size
+	 * (CONFIG_ENV_SIZE).  This heuristics will result in
+	 * unreasonably large numbers (and thus memory footprint) for
+	 * big flash environments (>8,000 entries for 64 KB
+	 * envrionment size), so we clip it to a reasonable value.
+	 * On the other hand we need to add some more entries for free
+	 * space when importing very small buffers. Both boundaries can
+	 * be overwritten in the board config file if needed.
+	 */
+
+	if (!htab->table) {
+		int nent = CONFIG_ENV_MIN_ENTRIES + size / 8;
+
+		if (nent > CONFIG_ENV_MAX_ENTRIES)
+			nent = CONFIG_ENV_MAX_ENTRIES;
+
+		debug("Create Hash Table: N=%d\n", nent);
+
+		if (hcreate_r(nent, htab) == 0) {
+			free(data);
+			return 0;
+		}
+	}
+
+	/* Parse environment; allow for '\0' and 'sep' as separators */
+	do {
+		ENTRY e, *rv;
+
+		/* skip leading white space */
+		while (isblank(*dp))
+			++dp;
+
+		/* skip comment lines */
+		if (*dp == '#') {
+			while (*dp && (*dp != sep))
+				++dp;
+			++dp;
+			continue;
+		}
+
+		/* parse name */
+		for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp)
+			;
+
+		/* deal with "name" and "name=" entries (delete var) */
+		if (*dp == '\0' || *(dp + 1) == '\0' ||
+		    *dp == sep || *(dp + 1) == sep) {
+			if (*dp == '=')
+				*dp++ = '\0';
+			*dp++ = '\0';	/* terminate name */
+
+			debug("DELETE CANDIDATE: \"%s\"\n", name);
+			if (!drop_var_from_set(name, nvars, localvars))
+				continue;
+
+			if (hdelete_r(name, htab, flag) == 0)
+				debug("DELETE ERROR ##############################\n");
+
+			continue;
+		}
+		*dp++ = '\0';	/* terminate name */
+
+		/* parse value; deal with escapes */
+		for (value = sp = dp; *dp && (*dp != sep); ++dp) {
+			if ((*dp == '\\') && *(dp + 1))
+				++dp;
+			*sp++ = *dp;
+		}
+		*sp++ = '\0';	/* terminate value */
+		++dp;
+
+		if (*name == 0) {
+			debug("INSERT: unable to use an empty key\n");
+			__set_errno(EINVAL);
+			return 0;
+		}
+
+		/* Skip variables which are not supposed to be processed */
+		if (!drop_var_from_set(name, nvars, localvars))
+			continue;
+
+		/* enter into hash table */
+		e.key = name;
+		e.data = value;
+
+		hsearch_r(e, ENTER, &rv, htab, flag);
+		if (rv == NULL)
+			printf("himport_r: can't insert \"%s=%s\" into hash table\n",
+				name, value);
+
+		debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n",
+			htab, htab->filled, htab->size,
+			rv, name, value);
+	} while ((dp < data + size) && *dp);	/* size check needed for text */
+						/* without '\0' termination */
+	debug("INSERT: free(data = %p)\n", data);
+	free(data);
+
+	/* process variables which were not considered */
+	for (i = 0; i < nvars; i++) {
+		if (localvars[i] == NULL)
+			continue;
+		/*
+		 * All variables which were not deleted from the variable list
+		 * were not present in the imported env
+		 * This could mean two things:
+		 * a) if the variable was present in current env, we delete it
+		 * b) if the variable was not present in current env, we notify
+		 *    it might be a typo
+		 */
+		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]);
+	}
+
+	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;
+}