diff options
| author | Phil Sutter <phil@nwl.cc> | 2024-02-27 18:47:39 +0100 |
|---|---|---|
| committer | Phil Sutter <phil@nwl.cc> | 2024-02-27 19:41:02 +0100 |
| commit | bb1a7a5b297aa271f7f59abbcb891cd94d7fb305 (patch) | |
| tree | 57e06b2850481fd6466bfe357b7a4d4bfd1b6a9f /iptables | |
| parent | ff57cd48d2b0c01c1519fd8893fc0432ad211702 (diff) | |
nft: Fix for broken recover_rule_compat()
When IPv4 rule generator was changed to emit payload instead of
meta expressions for l4proto matches, the code reinserting
NFTNL_RULE_COMPAT_* attributes into rules being reused for counter
zeroing was broken by accident.
Make rule compat recovery aware of the alternative match, basically
reinstating the effect of commit 7a373f6683afb ("nft: Fix -Z for rules
with NFTA_RULE_COMPAT") but add a test case this time to make sure
things stay intact.
Fixes: 69278f9602b43 ("nft: use payload matching for layer 4 protocol")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Diffstat (limited to 'iptables')
| -rw-r--r-- | iptables/nft.c | 27 | ||||
| -rwxr-xr-x | iptables/tests/shell/testcases/nft-only/0011-zero-needs-compat_0 | 12 |
2 files changed, 35 insertions, 4 deletions
diff --git a/iptables/nft.c b/iptables/nft.c index dae6698d..ee63c3dc 100644 --- a/iptables/nft.c +++ b/iptables/nft.c @@ -3750,6 +3750,27 @@ const char *nft_strerror(int err) return strerror(err); } +static int l4proto_expr_get_dreg(struct nftnl_expr *e, uint32_t *dregp) +{ + const char *name = nftnl_expr_get_str(e, NFTNL_EXPR_NAME); + uint32_t poff = offsetof(struct iphdr, protocol); + uint32_t pbase = NFT_PAYLOAD_NETWORK_HEADER; + + if (!strcmp(name, "payload") && + nftnl_expr_get_u32(e, NFTNL_EXPR_PAYLOAD_BASE) == pbase && + nftnl_expr_get_u32(e, NFTNL_EXPR_PAYLOAD_OFFSET) == poff && + nftnl_expr_get_u32(e, NFTNL_EXPR_PAYLOAD_LEN) == sizeof(uint8_t)) { + *dregp = nftnl_expr_get_u32(e, NFTNL_EXPR_PAYLOAD_DREG); + return 0; + } + if (!strcmp(name, "meta") && + nftnl_expr_get_u32(e, NFTNL_EXPR_META_KEY) == NFT_META_L4PROTO) { + *dregp = nftnl_expr_get_u32(e, NFTNL_EXPR_META_DREG); + return 0; + } + return -1; +} + static int recover_rule_compat(struct nftnl_rule *r) { struct nftnl_expr_iter *iter; @@ -3766,12 +3787,10 @@ next_expr: if (!e) goto out; - if (strcmp("meta", nftnl_expr_get_str(e, NFTNL_EXPR_NAME)) || - nftnl_expr_get_u32(e, NFTNL_EXPR_META_KEY) != NFT_META_L4PROTO) + /* may be 'ip protocol' or 'meta l4proto' with identical RHS */ + if (l4proto_expr_get_dreg(e, ®) < 0) goto next_expr; - reg = nftnl_expr_get_u32(e, NFTNL_EXPR_META_DREG); - e = nftnl_expr_iter_next(iter); if (!e) goto out; diff --git a/iptables/tests/shell/testcases/nft-only/0011-zero-needs-compat_0 b/iptables/tests/shell/testcases/nft-only/0011-zero-needs-compat_0 new file mode 100755 index 00000000..e276a953 --- /dev/null +++ b/iptables/tests/shell/testcases/nft-only/0011-zero-needs-compat_0 @@ -0,0 +1,12 @@ +#!/bin/bash + +[[ $XT_MULTI == *xtables-nft-multi ]] || { echo "skip $XT_MULTI"; exit 0; } + +set -e + +rule="-p tcp -m tcp --dport 27374 -c 23 42 -j TPROXY --on-port 50080" +for cmd in iptables ip6tables; do + $XT_MULTI $cmd -t mangle -A PREROUTING $rule + $XT_MULTI $cmd -t mangle -Z + $XT_MULTI $cmd -t mangle -v -S | grep -q -- "${rule/23 42/0 0}" +done |