X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fuci.git;a=blobdiff_plain;f=list.c;h=006e2a0ca8d2741f84731c62fc80eecebf877ef9;hp=8d73f11405ebad863a4c1fa5228b83c7f6620ccf;hb=ec8cbbbe0f20e67cbd3bd471b9ac55ceacaef7b8;hpb=f7df28b4d0155c780fa46a09d2dbcf7825faebae

diff --git a/list.c b/list.c
index 8d73f11..006e2a0 100644
--- a/list.c
+++ b/list.c
@@ -2,207 +2,715 @@
  * libuci - Library for the Unified Configuration Interface
  * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
  *
- * this program is free software; you can redistribute it and/or modify
- * it under the terms of the gnu lesser general public license version 2.1
- * as published by the free software foundation
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
+ * GNU Lesser General Public License for more details.
  */
 
-#include <glob.h>
+static void uci_list_set_pos(struct uci_list *head, struct uci_list *ptr, int pos)
+{
+	struct uci_list *new_head = head;
+	struct uci_element *p = NULL;
+
+	uci_list_del(ptr);
+	uci_foreach_element(head, p) {
+		if (pos-- <= 0)
+			break;
+		new_head = &p->list;
+	}
 
-/* initialize a list head/item */
-static inline void uci_list_init(struct uci_list *ptr)
+	uci_list_add(new_head->next, ptr);
+}
+
+static inline void uci_list_fixup(struct uci_list *ptr)
 {
-	ptr->prev = ptr;
-	ptr->next = ptr;
+	ptr->prev->next = ptr;
+	ptr->next->prev = ptr;
 }
 
-/* inserts a new list entry between two consecutive entries */
-static inline void __uci_list_add(struct uci_list *prev, struct uci_list *next, struct uci_list *ptr)
+/* 
+ * uci_alloc_generic allocates a new uci_element with payload
+ * payload is appended to the struct to save memory and reduce fragmentation
+ */
+__private struct uci_element *
+uci_alloc_generic(struct uci_context *ctx, int type, const char *name, int size)
 {
-	prev->next = ptr;
-	next->prev = ptr;
-	ptr->prev = prev;
-	ptr->next = next;
+	struct uci_element *e;
+	int datalen = size;
+	void *ptr;
+
+	ptr = uci_malloc(ctx, datalen);
+	e = (struct uci_element *) ptr;
+	e->type = type;
+	if (name) {
+		UCI_TRAP_SAVE(ctx, error);
+		e->name = uci_strdup(ctx, name);
+		UCI_TRAP_RESTORE(ctx);
+	}
+	uci_list_init(&e->list);
+	goto done;
+
+error:
+	free(ptr);
+	UCI_THROW(ctx, ctx->err);
+
+done:
+	return e;
 }
 
-/* inserts a new list entry at the tail of the list */
-static inline void uci_list_add(struct uci_list *head, struct uci_list *ptr)
+__private void
+uci_free_element(struct uci_element *e)
 {
-	/* NB: head->prev points at the tail */
-	__uci_list_add(head->prev, head, ptr);
+	if (e->name)
+		free(e->name);
+	if (!uci_list_empty(&e->list))
+		uci_list_del(&e->list);
+	free(e);
 }
 
-static inline void uci_list_del(struct uci_list *ptr)
+static struct uci_option *
+uci_alloc_option(struct uci_section *s, const char *name, const char *value)
 {
-	struct uci_list *next, *prev;
+	struct uci_package *p = s->package;
+	struct uci_context *ctx = p->ctx;
+	struct uci_option *o;
+
+	o = uci_alloc_element(ctx, option, name, strlen(value) + 1);
+	o->type = UCI_TYPE_STRING;
+	o->v.string = uci_dataptr(o);
+	o->section = s;
+	strcpy(o->v.string, value);
+	uci_list_add(&s->options, &o->e.list);
+
+	return o;
+}
 
-	next = ptr->next;
-	prev = ptr->prev;
+static inline void
+uci_free_option(struct uci_option *o)
+{
+	struct uci_element *e, *tmp;
+
+	switch(o->type) {
+	case UCI_TYPE_STRING:
+		if ((o->v.string != uci_dataptr(o)) &&
+			(o->v.string != NULL))
+			free(o->v.string);
+		break;
+	case UCI_TYPE_LIST:
+		uci_foreach_element_safe(&o->v.list, tmp, e) {
+			uci_free_element(e);
+		}
+		break;
+	default:
+		break;
+	}
+	uci_free_element(&o->e);
+}
+
+static struct uci_option *
+uci_alloc_list(struct uci_section *s, const char *name)
+{
+	struct uci_package *p = s->package;
+	struct uci_context *ctx = p->ctx;
+	struct uci_option *o;
 
-	prev->next = next;
-	next->prev = prev;
+	o = uci_alloc_element(ctx, option, name, 0);
+	o->type = UCI_TYPE_LIST;
+	o->section = s;
+	uci_list_init(&o->v.list);
+	uci_list_add(&s->options, &o->e.list);
+
+	return o;
 }
 
-static void uci_drop_option(struct uci_option *option)
+/* Based on an efficient hash function published by D. J. Bernstein */
+static unsigned int djbhash(unsigned int hash, char *str)
 {
-	if (!option)
+	int len = strlen(str);
+	int i;
+
+	/* initial value */
+	if (hash == ~0)
+		hash = 5381;
+
+	for(i = 0; i < len; i++) {
+		hash = ((hash << 5) + hash) + str[i];
+	}
+	return (hash & 0x7FFFFFFF);
+}
+
+/* fix up an unnamed section, e.g. after adding options to it */
+__private void uci_fixup_section(struct uci_context *ctx, struct uci_section *s)
+{
+	unsigned int hash = ~0;
+	struct uci_element *e;
+	char buf[16];
+
+	if (!s || s->e.name)
 		return;
-	if (option->name)
-		free(option->name);
-	if (option->value)
-		free(option->value);
-	free(option);
+
+	/*
+	 * Generate a name for unnamed sections. This is used as reference
+	 * when locating or updating the section from apps/scripts.
+	 * To make multiple concurrent versions somewhat safe for updating,
+	 * the name is generated from a hash of its type and name/value
+	 * pairs of its option, and it is prefixed by a counter value.
+	 * If the order of the unnamed sections changes for some reason,
+	 * updates to them will be rejected.
+	 */
+	hash = djbhash(hash, s->type);
+	uci_foreach_element(&s->options, e) {
+		struct uci_option *o;
+		hash = djbhash(hash, e->name);
+		o = uci_to_option(e);
+		switch(o->type) {
+		case UCI_TYPE_STRING:
+			hash = djbhash(hash, o->v.string);
+			break;
+		default:
+			break;
+		}
+	}
+	sprintf(buf, "cfg%02x%04x", ++s->package->n_section, hash % (1 << 16));
+	s->e.name = uci_strdup(ctx, buf);
 }
 
-static struct uci_option *uci_add_option(struct uci_section *section, const char *name, const char *value)
+static struct uci_section *
+uci_alloc_section(struct uci_package *p, const char *type, const char *name)
 {
-	struct uci_config *cfg = section->config;
-	struct uci_context *ctx = cfg->ctx;
-	struct uci_option *option = NULL;
+	struct uci_context *ctx = p->ctx;
+	struct uci_section *s;
 
-	UCI_TRAP_SAVE(ctx, error);
-	option = (struct uci_option *) uci_malloc(ctx, sizeof(struct uci_option));
-	option->name = uci_strdup(ctx, name);
-	option->value = uci_strdup(ctx, value);
-	uci_list_add(&section->options, &option->list);
-	UCI_TRAP_RESTORE(ctx);
+	if (name && !name[0])
+		name = NULL;
 
-error:
-	uci_drop_option(option);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	s = uci_alloc_element(ctx, section, name, strlen(type) + 1);
+	uci_list_init(&s->options);
+	s->type = uci_dataptr(s);
+	s->package = p;
+	strcpy(s->type, type);
+	if (name == NULL)
+		s->anonymous = true;
+	p->n_section++;
+
+	uci_list_add(&p->sections, &s->e.list);
+
+	return s;
+}
+
+static void
+uci_free_section(struct uci_section *s)
+{
+	struct uci_element *o, *tmp;
+
+	uci_foreach_element_safe(&s->options, tmp, o) {
+		uci_free_option(uci_to_option(o));
+	}
+	if ((s->type != uci_dataptr(s)) &&
+		(s->type != NULL))
+		free(s->type);
+	uci_free_element(&s->e);
+}
+
+__plugin struct uci_package *
+uci_alloc_package(struct uci_context *ctx, const char *name)
+{
+	struct uci_package *p;
+
+	p = uci_alloc_element(ctx, package, name, 0);
+	p->ctx = ctx;
+	uci_list_init(&p->sections);
+	uci_list_init(&p->delta);
+	uci_list_init(&p->saved_delta);
+	return p;
 }
 
-static void uci_drop_section(struct uci_section *section)
+__private void
+uci_free_package(struct uci_package **package)
 {
-	struct uci_option *opt;
+	struct uci_element *e, *tmp;
+	struct uci_package *p = *package;
 
-	if (!section)
+	if(!p)
 		return;
 
-	uci_foreach_entry(option, &section->options, opt) {
-		uci_list_del(&opt->list);
-		uci_drop_option(opt);
+	if (p->path)
+		free(p->path);
+	uci_foreach_element_safe(&p->sections, tmp, e) {
+		uci_free_section(uci_to_section(e));
+	}
+	uci_foreach_element_safe(&p->delta, tmp, e) {
+		uci_free_delta(uci_to_delta(e));
+	}
+	uci_foreach_element_safe(&p->saved_delta, tmp, e) {
+		uci_free_delta(uci_to_delta(e));
 	}
+	uci_free_element(&p->e);
+	*package = NULL;
+}
 
-	if (section->name)
-		free(section->name);
-	if (section->type)
-		free(section->type);
-	free(section);
+static void
+uci_free_any(struct uci_element **e)
+{
+	switch((*e)->type) {
+	case UCI_TYPE_SECTION:
+		uci_free_section(uci_to_section(*e));
+		break;
+	case UCI_TYPE_OPTION:
+		uci_free_option(uci_to_option(*e));
+		break;
+	default:
+		break;
+	}
+	*e = NULL;
 }
 
-static struct uci_section *uci_add_section(struct uci_config *cfg, const char *type, const char *name)
+__private struct uci_element *
+uci_lookup_list(struct uci_list *list, const char *name)
 {
-	struct uci_section *section = NULL;
-	struct uci_context *ctx = cfg->ctx;
+	struct uci_element *e;
 
-	UCI_TRAP_SAVE(ctx, error);
-	section = (struct uci_section *) uci_malloc(ctx, sizeof(struct uci_section));
-	section->config = cfg;
-	uci_list_init(&section->list);
-	uci_list_init(&section->options);
-	section->type = uci_strdup(ctx, type);
-	if (name)
-		section->name = uci_strdup(ctx, name);
-	uci_list_add(&cfg->sections, &section->list);
-	UCI_TRAP_RESTORE(ctx);
+	uci_foreach_element(list, e) {
+		if (!strcmp(e->name, name))
+			return e;
+	}
+	return NULL;
+}
 
-	return section;
+static struct uci_element *
+uci_lookup_ext_section(struct uci_context *ctx, struct uci_ptr *ptr)
+{
+	char *idxstr, *t, *section, *name;
+	struct uci_element *e = NULL;
+	struct uci_section *s;
+	int idx, c;
+
+	section = uci_strdup(ctx, ptr->section);
+	name = idxstr = section + 1;
+
+	if (section[0] != '@')
+		goto error;
+
+	/* parse the section index part */
+	idxstr = strchr(idxstr, '[');
+	if (!idxstr)
+		goto error;
+	*idxstr = 0;
+	idxstr++;
+
+	t = strchr(idxstr, ']');
+	if (!t)
+		goto error;
+	if (t[1] != 0)
+		goto error;
+	*t = 0;
+
+	t = NULL;
+	idx = strtol(idxstr, &t, 10);
+	if (t && *t)
+		goto error;
+
+	if (!*name)
+		name = NULL;
+	else if (!uci_validate_type(name))
+		goto error;
+
+	/* if the given index is negative, it specifies the section number from 
+	 * the end of the list */
+	if (idx < 0) {
+		c = 0;
+		uci_foreach_element(&ptr->p->sections, e) {
+			s = uci_to_section(e);
+			if (name && (strcmp(s->type, name) != 0))
+				continue;
+
+			c++;
+		}
+		idx += c;
+	}
+
+	c = 0;
+	uci_foreach_element(&ptr->p->sections, e) {
+		s = uci_to_section(e);
+		if (name && (strcmp(s->type, name) != 0))
+			continue;
+
+		if (idx == c)
+			goto done;
+		c++;
+	}
+	e = NULL;
+	goto done;
 
 error:
-	uci_drop_section(section);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	e = NULL;
+	memset(ptr, 0, sizeof(struct uci_ptr));
+	UCI_THROW(ctx, UCI_ERR_INVAL);
+done:
+	free(section);
+	if (e)
+		ptr->section = e->name;
+	return e;
 }
 
-static void uci_drop_config(struct uci_config *cfg)
+int
+uci_lookup_next(struct uci_context *ctx, struct uci_element **e, struct uci_list *list, const char *name)
 {
-	struct uci_section *s;
+	UCI_HANDLE_ERR(ctx);
 
-	if(!cfg)
-		return;
+	*e = uci_lookup_list(list, name);
+	if (!*e)
+		UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+
+	return 0;
+}
+
+int
+uci_lookup_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str, bool extended)
+{
+	struct uci_element *e;
+
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, ptr != NULL);
+
+	if (str)
+		UCI_INTERNAL(uci_parse_ptr, ctx, ptr, str);
+
+	ptr->flags |= UCI_LOOKUP_DONE;
+
+	/* look up the package first */
+	if (ptr->p)
+		e = &ptr->p->e;
+	else
+		e = uci_lookup_list(&ctx->root, ptr->package);
+
+	if (!e) {
+		UCI_INTERNAL(uci_load, ctx, ptr->package, &ptr->p);
+		if (!ptr->p)
+			goto notfound;
+		ptr->last = &ptr->p->e;
+	} else {
+		ptr->p = uci_to_package(e);
+		ptr->last = e;
+	}
+
+	if (!ptr->section && !ptr->s)
+		goto complete;
+
+	/* if the section name validates as a regular name, pass through
+	 * to the regular uci_lookup function call */
+	if (ptr->s) {
+		e = &ptr->s->e;
+	} else if (ptr->flags & UCI_LOOKUP_EXTENDED) {
+		if (extended)
+			e = uci_lookup_ext_section(ctx, ptr);
+		else
+			UCI_THROW(ctx, UCI_ERR_INVAL);
+	} else {
+		e = uci_lookup_list(&ptr->p->sections, ptr->section);
+	}
+
+	if (!e)
+		goto abort;
+
+	ptr->last = e;
+	ptr->s = uci_to_section(e);
+
+	if (ptr->option) {
+		e = uci_lookup_list(&ptr->s->options, ptr->option);
+		if (!e)
+			goto abort;
+
+		ptr->o = uci_to_option(e);
+		ptr->last = e;
+	}
+
+complete:
+	ptr->flags |= UCI_LOOKUP_COMPLETE;
+abort:
+	return 0;
+
+notfound:
+	UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+	return 0;
+}
+
+__private struct uci_element *
+uci_expand_ptr(struct uci_context *ctx, struct uci_ptr *ptr, bool complete)
+{
+	UCI_ASSERT(ctx, ptr != NULL);
+
+	if (!(ptr->flags & UCI_LOOKUP_DONE))
+		UCI_INTERNAL(uci_lookup_ptr, ctx, ptr, NULL, 1);
+	if (complete && !(ptr->flags & UCI_LOOKUP_COMPLETE))
+		UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+	UCI_ASSERT(ctx, ptr->p != NULL);
+
+	/* fill in missing string info */
+	if (ptr->p && !ptr->package)
+		ptr->package = ptr->p->e.name;
+	if (ptr->s && !ptr->section)
+		ptr->section = ptr->s->e.name;
+	if (ptr->o && !ptr->option)
+		ptr->option = ptr->o->e.name;
+
+	if (ptr->o)
+		return &ptr->o->e;
+	if (ptr->s)
+		return &ptr->s->e;
+	if (ptr->p)
+		return &ptr->p->e;
+	else
+		return NULL;
+}
+
+static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, bool internal)
+{
+	struct uci_element *e;
+	struct uci_package *p;
+
+	p = ptr->p;
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
+
+	e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
+	uci_list_add(&ptr->o->v.list, &e->list);
+}
+
+int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
+{
+	/* NB: UCI_INTERNAL use means without delta tracking */
+	bool internal = ctx && ctx->internal;
+	struct uci_element *e;
+	struct uci_package *p;
+	char *n;
+
+	UCI_HANDLE_ERR(ctx);
+
+	e = uci_expand_ptr(ctx, ptr, true);
+	p = ptr->p;
 
-	uci_foreach_entry(section, &cfg->sections, s) {
-		uci_list_del(&s->list);
-		uci_drop_section(s);
+	UCI_ASSERT(ctx, ptr->s);
+	UCI_ASSERT(ctx, ptr->value);
+
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
+
+	n = uci_strdup(ctx, ptr->value);
+	if (e->name)
+		free(e->name);
+	e->name = n;
+
+	if (e->type == UCI_TYPE_SECTION)
+		uci_to_section(e)->anonymous = false;
+
+	return 0;
+}
+
+int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
+{
+	struct uci_package *p = s->package;
+	char order[32];
+
+	UCI_HANDLE_ERR(ctx);
+
+	uci_list_set_pos(&s->package->sections, &s->e.list, pos);
+	if (!ctx->internal && p->has_delta) {
+		sprintf(order, "%d", pos);
+		uci_add_delta(ctx, &p->delta, UCI_CMD_REORDER, s->e.name, NULL, order);
 	}
 
-	if (cfg->name)
-		free(cfg->name);
-	free(cfg);
+	return 0;
 }
 
+int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *type, struct uci_section **res)
+{
+	bool internal = ctx && ctx->internal;
+	struct uci_section *s;
+
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, p != NULL);
+	s = uci_alloc_section(p, type, NULL);
+	uci_fixup_section(ctx, s);
+	*res = s;
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_ADD, s->e.name, NULL, type);
+
+	return 0;
+}
 
-static struct uci_config *uci_alloc_config(struct uci_context *ctx, const char *name)
+int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	struct uci_config *cfg = NULL;
+	/* NB: pass on internal flag to uci_del_element */
+	bool internal = ctx && ctx->internal;
+	struct uci_package *p;
+	struct uci_element *e;
 
-	UCI_TRAP_SAVE(ctx, error);
-	cfg = (struct uci_config *) uci_malloc(ctx, sizeof(struct uci_config));
-	uci_list_init(&cfg->list);
-	uci_list_init(&cfg->sections);
-	cfg->name = uci_strdup(ctx, name);
-	cfg->ctx = ctx;
-	UCI_TRAP_RESTORE(ctx);
-	return cfg;
+	UCI_HANDLE_ERR(ctx);
 
-error:
-	uci_drop_config(cfg);
-	UCI_THROW(ctx, ctx->errno);
-	return NULL;
+	e = uci_expand_ptr(ctx, ptr, true);
+	p = ptr->p;
+
+	UCI_ASSERT(ctx, ptr->s);
+
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
+
+	uci_free_any(&e);
+
+	if (ptr->option)
+		ptr->o = NULL;
+	else if (ptr->section)
+		ptr->s = NULL;
+
+	return 0;
 }
 
-int uci_unload(struct uci_context *ctx, const char *name)
+int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	struct uci_config *cfg;
+	/* NB: UCI_INTERNAL use means without delta tracking */
+	bool internal = ctx && ctx->internal;
+	struct uci_option *prev = NULL;
+	const char *value2 = NULL;
 
 	UCI_HANDLE_ERR(ctx);
-	UCI_ASSERT(ctx, name != NULL);
 
-	uci_foreach_entry(config, &ctx->root, cfg) {
-		if (!strcmp(cfg->name, name))
-			goto found;
+	uci_expand_ptr(ctx, ptr, false);
+	UCI_ASSERT(ctx, ptr->s);
+	UCI_ASSERT(ctx, ptr->value);
+
+	if (ptr->o) {
+		switch (ptr->o->type) {
+		case UCI_TYPE_STRING:
+			/* we already have a string value, convert that to a list */
+			prev = ptr->o;
+			value2 = ptr->value;
+			ptr->value = ptr->o->v.string;
+			break;
+		case UCI_TYPE_LIST:
+			uci_add_element_list(ctx, ptr, internal);
+			return 0;
+		default:
+			UCI_THROW(ctx, UCI_ERR_INVAL);
+			break;
+		}
 	}
-	UCI_THROW(ctx, UCI_ERR_NOTFOUND);
 
-found:
-	uci_list_del(&cfg->list);
-	uci_drop_config(cfg);
+	ptr->o = uci_alloc_list(ptr->s, ptr->option);
+	if (prev) {
+		uci_add_element_list(ctx, ptr, true);
+		uci_free_option(prev);
+		ptr->value = value2;
+	}
+	uci_add_element_list(ctx, ptr, internal);
 
 	return 0;
 }
 
-char **uci_list_configs(struct uci_context *ctx)
+int uci_del_list(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	char **configs;
-	glob_t globbuf;
-	int size, i;
-	char *buf;
+	/* NB: pass on internal flag to uci_del_element */
+	bool internal = ctx && ctx->internal;
+	struct uci_element *e, *tmp;
+	struct uci_package *p;
 
-	if (glob(UCI_CONFDIR "/*", GLOB_MARK, NULL, &globbuf) != 0)
-		return NULL;
+	UCI_HANDLE_ERR(ctx);
 
-	size = sizeof(char *) * (globbuf.gl_pathc + 1);
-	for(i = 0; i < globbuf.gl_pathc; i++)
-		size += strlen(globbuf.gl_pathv[i]) + 1;
+	uci_expand_ptr(ctx, ptr, false);
+	UCI_ASSERT(ctx, ptr->s);
+	UCI_ASSERT(ctx, ptr->value);
 
-	configs = malloc(size);
-	if (!configs)
-		return NULL;
+	if (!(ptr->o && ptr->option))
+		return 0;
 
-	memset(configs, 0, size);
-	buf = (char *) &configs[globbuf.gl_pathc + 1];
-	for(i = 0; i < globbuf.gl_pathc; i++) {
-		configs[i] = buf;
-		strcpy(buf, globbuf.gl_pathv[i]);
-		buf += strlen(buf) + 1;
+	if ((ptr->o->type != UCI_TYPE_LIST))
+		return 0;
+
+	p = ptr->p;
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_DEL, ptr->section, ptr->option, ptr->value);
+
+	uci_foreach_element_safe(&ptr->o->v.list, tmp, e) {
+		if (!strcmp(ptr->value, uci_to_option(e)->e.name)) {
+			uci_free_option(uci_to_option(e));
+		}
 	}
-	return configs;
+
+	return 0;
+}
+
+int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
+{
+	/* NB: UCI_INTERNAL use means without delta tracking */
+	bool internal = ctx && ctx->internal;
+
+	UCI_HANDLE_ERR(ctx);
+	uci_expand_ptr(ctx, ptr, false);
+	UCI_ASSERT(ctx, ptr->value);
+	UCI_ASSERT(ctx, ptr->s || (!ptr->option && ptr->section));
+	if (!ptr->option && ptr->value[0]) {
+		UCI_ASSERT(ctx, uci_validate_type(ptr->value));
+	}
+
+	if (!ptr->o && ptr->s && ptr->option) {
+		struct uci_element *e;
+		e = uci_lookup_list(&ptr->s->options, ptr->option);
+		if (e)
+			ptr->o = uci_to_option(e);
+	}
+	if (!ptr->value[0]) {
+		/* if setting a nonexistant option/section to a nonexistant value,
+		 * exit without errors */
+		if (!(ptr->flags & UCI_LOOKUP_COMPLETE))
+			return 0;
+
+		return uci_delete(ctx, ptr);
+	} else if (!ptr->o && ptr->option) { /* new option */
+		ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
+		ptr->last = &ptr->o->e;
+	} else if (!ptr->s && ptr->section) { /* new section */
+		ptr->s = uci_alloc_section(ptr->p, ptr->value, ptr->section);
+		ptr->last = &ptr->s->e;
+	} else if (ptr->o && ptr->option) { /* update option */
+		if ((ptr->o->type == UCI_TYPE_STRING) &&
+			!strcmp(ptr->o->v.string, ptr->value))
+			return 0;
+		uci_free_option(ptr->o);
+		ptr->o = uci_alloc_option(ptr->s, ptr->option, ptr->value);
+		ptr->last = &ptr->o->e;
+	} else if (ptr->s && ptr->section) { /* update section */
+		char *s = uci_strdup(ctx, ptr->value);
+
+		if (ptr->s->type == uci_dataptr(ptr->s)) {
+			ptr->last = NULL;
+			ptr->last = uci_realloc(ctx, ptr->s, sizeof(struct uci_section));
+			ptr->s = uci_to_section(ptr->last);
+			uci_list_fixup(&ptr->s->e.list);
+		} else {
+			free(ptr->s->type);
+		}
+		ptr->s->type = s;
+	} else {
+		UCI_THROW(ctx, UCI_ERR_INVAL);
+	}
+
+	if (!internal && ptr->p->has_delta)
+		uci_add_delta(ctx, &ptr->p->delta, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
+
+	return 0;
+}
+
+int uci_unload(struct uci_context *ctx, struct uci_package *p)
+{
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, p != NULL);
+
+	uci_free_package(&p);
+	return 0;
 }