+ struct uci_list *new_head = head;
+ struct uci_element *p = NULL;
+
+ uci_list_del(ptr);
+ uci_foreach_element(head, p) {
+ new_head = &p->list;
+ if (pos-- <= 0)
+ break;
+ }
+ uci_list_add(new_head, ptr);
+}
+
+static inline void uci_list_fixup(struct uci_list *ptr)
+{
+ ptr->prev->next = ptr;
+ ptr->next->prev = 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)
+{
+ 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;
+}
+
+__private void
+uci_free_element(struct uci_element *e)
+{
+ if (e->name)
+ free(e->name);
+ if (!uci_list_empty(&e->list))
+ uci_list_del(&e->list);
+ free(e);
+}
+
+static struct uci_option *
+uci_alloc_option(struct uci_section *s, const char *name, const char *value)
+{
+ 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;
+}
+
+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;
+
+ 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;
+}
+
+/* Based on an efficient hash function published by D. J. Bernstein */
+static unsigned int djbhash(unsigned int hash, char *str)
+{
+ 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;
+
+ /*
+ * 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_section *
+uci_alloc_section(struct uci_package *p, const char *type, const char *name)
+{
+ struct uci_context *ctx = p->ctx;
+ struct uci_section *s;
+
+ if (name && !name[0])
+ name = 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;
+}
+
+__private void
+uci_free_package(struct uci_package **package)
+{
+ struct uci_element *e, *tmp;
+ struct uci_package *p = *package;
+
+ if(!p)
+ return;
+
+ 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;
+}
+
+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;
+}
+
+__private struct uci_element *
+uci_lookup_list(struct uci_list *list, const char *name)
+{
+ struct uci_element *e;
+
+ uci_foreach_element(list, e) {
+ if (!strcmp(e->name, name))
+ return e;
+ }
+ return NULL;
+}
+
+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:
+ 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;