diff options
| author | Phil Sutter <phil@nwl.cc> | 2023-12-21 14:31:59 +0100 |
|---|---|---|
| committer | Florian Westphal <fw@strlen.de> | 2024-01-29 15:43:20 +0100 |
| commit | 31bf508be656a429a17e3adb31e9acae5c1a6299 (patch) | |
| tree | ce35b9e6d54ca3d486ab04fa5b53ac651fa4f79b /net/netfilter/nf_tables_api.c | |
| parent | da5141bbe0c2693d85f14a89ee991921904f4d0c (diff) | |
| download | linux-31bf508be656a429a17e3adb31e9acae5c1a6299.tar.gz | |
netfilter: nf_tables: Implement table adoption support
Allow a new process to take ownership of a previously owned table,
useful mostly for firewall management services restarting or suspending
when idle.
By extending __NFT_TABLE_F_UPDATE, the on/off/on check in
nf_tables_updtable() also covers table adoption, although it is actually
not needed: Table adoption is irreversible because nf_tables_updtable()
rejects attempts to drop NFT_TABLE_F_OWNER so table->nlpid setting can
happen just once within the transaction.
If the transaction commences, table's nlpid and flags fields are already
set and no further action is required. If it aborts, the table returns
to orphaned state.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net/netfilter/nf_tables_api.c')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 6a96f0003faa96..b0e0d039897eee 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1194,8 +1194,10 @@ static void nf_tables_table_disable(struct net *net, struct nft_table *table) #define __NFT_TABLE_F_INTERNAL (NFT_TABLE_F_MASK + 1) #define __NFT_TABLE_F_WAS_DORMANT (__NFT_TABLE_F_INTERNAL << 0) #define __NFT_TABLE_F_WAS_AWAKEN (__NFT_TABLE_F_INTERNAL << 1) +#define __NFT_TABLE_F_WAS_ORPHAN (__NFT_TABLE_F_INTERNAL << 2) #define __NFT_TABLE_F_UPDATE (__NFT_TABLE_F_WAS_DORMANT | \ - __NFT_TABLE_F_WAS_AWAKEN) + __NFT_TABLE_F_WAS_AWAKEN | \ + __NFT_TABLE_F_WAS_ORPHAN) static int nf_tables_updtable(struct nft_ctx *ctx) { @@ -1215,8 +1217,8 @@ static int nf_tables_updtable(struct nft_ctx *ctx) if ((nft_table_has_owner(ctx->table) && !(flags & NFT_TABLE_F_OWNER)) || - (!nft_table_has_owner(ctx->table) && - flags & NFT_TABLE_F_OWNER)) + (flags & NFT_TABLE_F_OWNER && + !nft_table_is_orphan(ctx->table))) return -EOPNOTSUPP; if ((flags ^ ctx->table->flags) & NFT_TABLE_F_PERSIST) @@ -1248,6 +1250,13 @@ static int nf_tables_updtable(struct nft_ctx *ctx) } } + if ((flags & NFT_TABLE_F_OWNER) && + !nft_table_has_owner(ctx->table)) { + ctx->table->nlpid = ctx->portid; + ctx->table->flags |= NFT_TABLE_F_OWNER | + __NFT_TABLE_F_WAS_ORPHAN; + } + nft_trans_table_update(trans) = true; nft_trans_commit_list_add_tail(ctx->net, trans); @@ -10423,6 +10432,10 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) } else if (trans->ctx.table->flags & __NFT_TABLE_F_WAS_AWAKEN) { trans->ctx.table->flags &= ~NFT_TABLE_F_DORMANT; } + if (trans->ctx.table->flags & __NFT_TABLE_F_WAS_ORPHAN) { + trans->ctx.table->flags &= ~NFT_TABLE_F_OWNER; + trans->ctx.table->nlpid = 0; + } trans->ctx.table->flags &= ~__NFT_TABLE_F_UPDATE; nft_trans_destroy(trans); } else { |