[libnftnl PATCH 2/2] chain: Add lookup functions for chain list and rules in chain

[Phil Sutter]

For now, these lookup functions simply iterate over the linked list
until they find the right entry. In future, they may make use of more
optimized data structures behind the curtains.

Signed-off-by: Phil Sutter <p...@nwl.cc>
---
 include/libnftnl/chain.h |  2 ++
 src/chain.c              | 28 ++++++++++++++++++++++++++++
 src/libnftnl.map         |  3 +++
 3 files changed, 33 insertions(+)

diff --git a/include/libnftnl/chain.h b/include/libnftnl/chain.h
index f04f61056cc7c..64e10e91aaefe 100644
--- a/include/libnftnl/chain.h
+++ b/include/libnftnl/chain.h
@@ -76,6 +76,7 @@ int nftnl_chain_nlmsg_parse(const struct nlmsghdr *nlh, 
struct nftnl_chain *t);
 int nftnl_rule_foreach(struct nftnl_chain *c,
                          int (*cb)(struct nftnl_rule *r, void *data),
                          void *data);
+struct nftnl_rule *nftnl_rule_lookup_byindex(struct nftnl_chain *c, uint32_t 
index);
 
 struct nftnl_rule_iter;
 
@@ -89,6 +90,7 @@ struct nftnl_chain_list *nftnl_chain_list_alloc(void);
 void nftnl_chain_list_free(struct nftnl_chain_list *list);
 int nftnl_chain_list_is_empty(const struct nftnl_chain_list *list);
 int nftnl_chain_list_foreach(struct nftnl_chain_list *chain_list, int 
(*cb)(struct nftnl_chain *t, void *data), void *data);
+struct nftnl_chain *nftnl_chain_list_lookup_byname(struct nftnl_chain_list 
*chain_list, const char *chain);
 
 void nftnl_chain_list_add(struct nftnl_chain *r, struct nftnl_chain_list 
*list);
 void nftnl_chain_list_add_tail(struct nftnl_chain *r, struct nftnl_chain_list 
*list);
diff --git a/src/chain.c b/src/chain.c
index c8b7f9ba12618..8668fb7d1494d 100644
--- a/src/chain.c
+++ b/src/chain.c
@@ -734,6 +734,20 @@ int nftnl_rule_foreach(struct nftnl_chain *c,
        return 0;
 }
 
+EXPORT_SYMBOL(nftnl_rule_lookup_byindex);
+struct nftnl_rule *
+nftnl_rule_lookup_byindex(struct nftnl_chain *c, uint32_t index)
+{
+       struct nftnl_rule *r;
+
+       list_for_each_entry(r, &c->rule_list, head) {
+               if (!index)
+                       return r;
+               index--;
+       }
+       return NULL;
+}
+
 struct nftnl_rule_iter {
        const struct nftnl_chain        *c;
        struct nftnl_rule               *cur;
@@ -856,6 +870,20 @@ int nftnl_chain_list_foreach(struct nftnl_chain_list 
*chain_list,
        return 0;
 }
 
+EXPORT_SYMBOL(nftnl_chain_list_lookup_byname);
+struct nftnl_chain *
+nftnl_chain_list_lookup_byname(struct nftnl_chain_list *chain_list,
+                              const char *chain)
+{
+       struct nftnl_chain *c;
+
+       list_for_each_entry(c, &chain_list->list, head) {
+               if (!strcmp(chain, c->name))
+                       return c;
+       }
+       return NULL;
+}
+
 struct nftnl_chain_list_iter {
        const struct nftnl_chain_list   *list;
        struct nftnl_chain              *cur;
diff --git a/src/libnftnl.map b/src/libnftnl.map
index 96d5b5f1cec49..0d3be32263eee 100644
--- a/src/libnftnl.map
+++ b/src/libnftnl.map
@@ -345,4 +345,7 @@ LIBNFTNL_12 {
   nftnl_rule_iter_create;
   nftnl_rule_iter_next;
   nftnl_rule_iter_destroy;
+
+  nftnl_chain_list_lookup_byname;
+  nftnl_rule_lookup_byindex;
 } LIBNFTNL_11;
-- 
2.19.0