From 7ea0b7d809229973d950ed99845bdd0b2eb4cbb7 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 15 Jan 2019 23:23:05 +0100 Subject: xtables: Fix for inserting rule at wrong position iptables-restore allows to insert rules at a certain position which is problematic for iptables-nft to realize since rule position is not determined by number but handle of previous or following rule and in case the rules surrounding the new one are new as well, they don't have a handle to refer to yet. Fix this by making use of NFTNL_RULE_POSITION_ID attribute: When inserting before a rule which does not have a handle, refer to it using its NFTNL_RULE_ID value. If the latter doesn't exist either, assign a new one to it. The last used rule ID value is tracked in a new field of struct nft_handle which is incremented before each use. Signed-off-by: Phil Sutter Signed-off-by: Pablo Neira Ayuso --- iptables/nft.c | 30 ++++-- iptables/nft.h | 1 + .../testcases/ipt-restore/0003-restore-ordering_0 | 117 +++++++++++++++++++++ .../shell/testcases/iptables/0005-rule-replace_0 | 38 +++++++ 4 files changed, 176 insertions(+), 10 deletions(-) create mode 100755 iptables/tests/shell/testcases/ipt-restore/0003-restore-ordering_0 create mode 100755 iptables/tests/shell/testcases/iptables/0005-rule-replace_0 diff --git a/iptables/nft.c b/iptables/nft.c index ee3d142b..83d373c9 100644 --- a/iptables/nft.c +++ b/iptables/nft.c @@ -2063,16 +2063,30 @@ int nft_rule_delete(struct nft_handle *h, const char *chain, static struct nftnl_rule * nft_rule_add(struct nft_handle *h, const char *chain, const char *table, struct iptables_command_state *cs, - uint64_t handle, bool verbose) + struct nftnl_rule *ref, bool verbose) { struct nftnl_rule *r; + uint64_t ref_id; r = nft_rule_new(h, chain, table, cs); if (r == NULL) return NULL; - if (handle > 0) - nftnl_rule_set_u64(r, NFTNL_RULE_POSITION, handle); + if (ref) { + ref_id = nftnl_rule_get_u64(ref, NFTNL_RULE_HANDLE); + if (ref_id > 0) { + nftnl_rule_set_u64(r, NFTNL_RULE_POSITION, ref_id); + DEBUGP("adding after rule handle %"PRIu64"\n", ref_id); + } else { + ref_id = nftnl_rule_get_u32(ref, NFTNL_RULE_ID); + if (!ref_id) { + ref_id = ++h->rule_id; + nftnl_rule_set_u32(ref, NFTNL_RULE_ID, ref_id); + } + nftnl_rule_set_u32(r, NFTNL_RULE_POSITION_ID, ref_id); + DEBUGP("adding after rule ID %"PRIu64"\n", ref_id); + } + } if (batch_rule_add(h, NFT_COMPAT_RULE_INSERT, r) < 0) { nftnl_rule_free(r); @@ -2088,9 +2102,8 @@ nft_rule_add(struct nft_handle *h, const char *chain, int nft_rule_insert(struct nft_handle *h, const char *chain, const char *table, void *data, int rulenum, bool verbose) { - struct nftnl_rule *r, *new_rule; + struct nftnl_rule *r = NULL, *new_rule; struct nftnl_chain *c; - uint64_t handle = 0; /* If built-in chains don't exist for this table, create them */ if (nft_xtables_config_load(h, XTABLES_CONFIG_DEFAULT, 0) < 0) @@ -2118,16 +2131,13 @@ int nft_rule_insert(struct nft_handle *h, const char *chain, errno = ENOENT; goto err; } - - handle = nftnl_rule_get_u64(r, NFTNL_RULE_HANDLE); - DEBUGP("adding after rule handle %"PRIu64"\n", handle); } - new_rule = nft_rule_add(h, chain, table, data, handle, verbose); + new_rule = nft_rule_add(h, chain, table, data, r, verbose); if (!new_rule) goto err; - if (handle) + if (r) nftnl_chain_rule_insert_at(new_rule, r); else nftnl_chain_rule_add(new_rule, c); diff --git a/iptables/nft.h b/iptables/nft.h index 97d73c8b..0726923a 100644 --- a/iptables/nft.h +++ b/iptables/nft.h @@ -32,6 +32,7 @@ struct nft_handle { struct mnl_socket *nl; uint32_t portid; uint32_t seq; + uint32_t rule_id; struct list_head obj_list; int obj_list_num; struct nftnl_batch *batch; diff --git a/iptables/tests/shell/testcases/ipt-restore/0003-restore-ordering_0 b/iptables/tests/shell/testcases/ipt-restore/0003-restore-ordering_0 new file mode 100755 index 00000000..51f2422e --- /dev/null +++ b/iptables/tests/shell/testcases/ipt-restore/0003-restore-ordering_0 @@ -0,0 +1,117 @@ +#!/bin/bash + +# Make sure iptables-restore does the right thing +# when encountering INSERT rules with index. + +set -e + +# show rules, drop uninteresting policy settings +ipt_show() { + $XT_MULTI iptables -S | grep -v '^-P' +} + +# basic issue reproducer + +$XT_MULTI iptables-restore <