Extend nft_chain_list_get() to accept an optional chain name callers are
interested in. If chain cache is not present yet, add a suitable payload
to NFT_MSG_GETCHAIN request to retrieve only that single chain. The
table's chain list will then contain only that chain.
Chain cache is considered present (i.e., have_chain_cache set to true)
only if fetch_chain_cache() was called without a specific chain name.
Therefore a full cache update could happen after fetching a specific
chain which means cache update preparation has to drop each table's
chain list to avoid duplicates.
With fetch_chain_cache() potentially ignoring all but a single table,
make fetch_rule_cache() aware of potentially uninitialized chain lists.
Rules are simply not fetched for those then.
Signed-off-by: Phil Sutter <p...@nwl.cc>
---
iptables/nft.c | 64 +++++++++++++++++++++++++++-----------
iptables/nft.h | 3 +-
iptables/xtables-restore.c | 2 +-
iptables/xtables-save.c | 2 +-
4 files changed, 50 insertions(+), 21 deletions(-)
diff --git a/iptables/nft.c b/iptables/nft.c
index 82c892ad96f34..46c7be372a10f 100644
--- a/iptables/nft.c
+++ b/iptables/nft.c
@@ -750,7 +750,7 @@ nft_chain_builtin_find(const struct builtin_table *t, const
char *chain)
static void nft_chain_builtin_init(struct nft_handle *h,
const struct builtin_table *table)
{
- struct nftnl_chain_list *list = nft_chain_list_get(h, table->name);
+ struct nftnl_chain_list *list = nft_chain_list_get(h, table->name,
NULL);
struct nftnl_chain *c;
int i;
@@ -1425,7 +1425,7 @@ static int fetch_table_cache(struct nft_handle *h)
return 1;
}
-static int fetch_chain_cache(struct nft_handle *h)
+static int fetch_chain_cache(struct nft_handle *h, const char *table, const
char *chain)
{
char buf[16536];
struct nlmsghdr *nlh;
@@ -1439,13 +1439,37 @@ static int fetch_chain_cache(struct nft_handle *h)
if (!h->tables[i].name)
continue;
+ /* When not fetching a single chain, kernel returns all chains
+ * of the given family which may belong to other tables than
+ * the expected one. Hence skip chain list initialization only
+ * if both chain and table are specified. */
+ if (chain && table && strcmp(table, h->tables[i].name))
+ continue;
+
+ if (h->cache->table[type].chains)
+ nftnl_chain_list_free(h->cache->table[type].chains);
+
h->cache->table[type].chains = nftnl_chain_list_alloc();
if (!h->cache->table[type].chains)
return -1;
}
- nlh = nftnl_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN, h->family,
- NLM_F_DUMP, h->seq);
+ if (table && chain) {
+ struct nftnl_chain *c;
+
+ nlh = nftnl_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN,
h->family,
+ NLM_F_ACK, h->seq);
+ c = nftnl_chain_alloc();
+ if (!c)
+ return -1;
+ nftnl_chain_set_str(c, NFTNL_CHAIN_TABLE, table);
+ nftnl_chain_set_str(c, NFTNL_CHAIN_NAME, chain);
+ nftnl_chain_nlmsg_build_payload(nlh, c);
+ nftnl_chain_free(c);
+ } else {
+ nlh = nftnl_chain_nlmsg_build_hdr(buf, NFT_MSG_GETCHAIN,
h->family,
+ NLM_F_DUMP, h->seq);
+ }
ret = mnl_talk(h, nlh, nftnl_chain_list_cb, h);
if (ret < 0 && errno == EINTR)
@@ -1596,6 +1620,9 @@ static int fetch_rule_cache(struct nft_handle *h)
if (!h->tables[i].name)
continue;
+ if (!h->cache->table[type].chains)
+ continue;
+
if (nftnl_chain_list_foreach(h->cache->table[type].chains,
nft_rule_list_update, h))
return -1;
@@ -1609,7 +1636,7 @@ static void __nft_build_cache(struct nft_handle *h)
retry:
mnl_genid_get(h, &genid_start);
- fetch_chain_cache(h);
+ fetch_chain_cache(h, NULL, NULL);
fetch_rule_cache(h);
h->have_chain_cache = true;
h->have_rule_cache = true;
@@ -1690,7 +1717,7 @@ static void nft_release_cache(struct nft_handle *h)
}
struct nftnl_chain_list *nft_chain_list_get(struct nft_handle *h,
- const char *table)
+ const char *table, const char
*chain)
{
const struct builtin_table *t;
@@ -1699,8 +1726,9 @@ struct nftnl_chain_list *nft_chain_list_get(struct
nft_handle *h,
return NULL;
if (!h->have_chain_cache) {
- fetch_chain_cache(h);
- h->have_chain_cache = true;
+ fetch_chain_cache(h, table, chain);
+ if (!chain)
+ h->have_chain_cache = true;
}
return h->cache->table[t->type].chains;
@@ -1782,7 +1810,7 @@ int nft_rule_save(struct nft_handle *h, const char
*table, unsigned int format)
struct nftnl_chain *c;
int ret = 0;
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, NULL);
if (!list)
return 0;
@@ -1845,7 +1873,7 @@ int nft_rule_flush(struct nft_handle *h, const char
*chain, const char *table,
nft_fn = nft_rule_flush;
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (list == NULL) {
ret = 1;
goto err;
@@ -1910,7 +1938,7 @@ int nft_chain_user_add(struct nft_handle *h, const char
*chain, const char *tabl
ret = batch_chain_add(h, NFT_COMPAT_CHAIN_USER_ADD, c);
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, NULL);
if (list)
nftnl_chain_list_add(c, list);
@@ -1950,7 +1978,7 @@ int nft_chain_restore(struct nft_handle *h, const char
*chain, const char *table
ret = batch_chain_add(h, NFT_COMPAT_CHAIN_USER_ADD, c);
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (list)
nftnl_chain_list_add(c, list);
@@ -2005,7 +2033,7 @@ int nft_chain_user_del(struct nft_handle *h, const char
*chain,
nft_fn = nft_chain_user_del;
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (list == NULL)
return 0;
@@ -2037,7 +2065,7 @@ nft_chain_find(struct nft_handle *h, const char *table,
const char *chain)
{
struct nftnl_chain_list *list;
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (list == NULL)
return NULL;
@@ -2584,7 +2612,7 @@ int nft_rule_list(struct nft_handle *h, const char
*chain, const char *table,
return 0;
}
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (!list)
return 0;
@@ -2687,7 +2715,7 @@ int nft_rule_list_save(struct nft_handle *h, const char
*chain,
return 0;
}
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (!list)
return 0;
@@ -3371,7 +3399,7 @@ int nft_chain_zero_counters(struct nft_handle *h, const
char *chain,
struct nftnl_chain *c;
int ret = 0;
- list = nft_chain_list_get(h, table);
+ list = nft_chain_list_get(h, table, chain);
if (list == NULL)
goto err;
@@ -3479,7 +3507,7 @@ bool nft_is_table_compatible(struct nft_handle *h, const
char *tablename)
{
struct nftnl_chain_list *clist;
- clist = nft_chain_list_get(h, tablename);
+ clist = nft_chain_list_get(h, tablename, NULL);
if (clist == NULL)
return false;
diff --git a/iptables/nft.h b/iptables/nft.h
index 718acdbf0c55d..4b1c191effbd6 100644
--- a/iptables/nft.h
+++ b/iptables/nft.h
@@ -98,7 +98,8 @@ struct nftnl_chain;
int nft_chain_set(struct nft_handle *h, const char *table, const char *chain,
const char *policy, const struct xt_counters *counters);
struct nftnl_chain_list *nft_chain_list_get(struct nft_handle *h,
- const char *table);
+ const char *table,
+ const char *chain);
int nft_chain_save(struct nft_handle *h, struct nftnl_chain_list *list);
int nft_chain_user_add(struct nft_handle *h, const char *chain, const char
*table);
int nft_chain_user_del(struct nft_handle *h, const char *chain, const char
*table, bool verbose);
diff --git a/iptables/xtables-restore.c b/iptables/xtables-restore.c
index d1486afedc480..835a21be7324f 100644
--- a/iptables/xtables-restore.c
+++ b/iptables/xtables-restore.c
@@ -62,7 +62,7 @@ static struct nftnl_chain_list *get_chain_list(struct
nft_handle *h,
{
struct nftnl_chain_list *chain_list;
- chain_list = nft_chain_list_get(h, table);
+ chain_list = nft_chain_list_get(h, table, NULL);
if (chain_list == NULL)
xtables_error(OTHER_PROBLEM, "cannot retrieve chain list\n");
diff --git a/iptables/xtables-save.c b/iptables/xtables-save.c
index 77b13f7ffbcdd..503ae401737c5 100644
--- a/iptables/xtables-save.c
+++ b/iptables/xtables-save.c
@@ -82,7 +82,7 @@ __do_output(struct nft_handle *h, const char *tablename, void
*data)
return 0;
}
- chain_list = nft_chain_list_get(h, tablename);
+ chain_list = nft_chain_list_get(h, tablename, NULL);
if (!chain_list)
return 0;
--
2.23.0
