From 76b82c425818ee246ed1100997d6e2a09f07976f Mon Sep 17 00:00:00 2001 From: "Jose M. Guisado Gomez" Date: Mon, 21 Sep 2020 15:28:22 +0200 Subject: chain: add userdata and comment support Adds NFTNL_CHAIN_USERDATA, in order to support userdata for chains. Adds NFTNL_UDATA_CHAIN_COMMENT chain userdata type to support storing a comment. Relies on NFTA_CHAIN_USERDATA. Signed-off-by: Jose M. Guisado Gomez Signed-off-by: Pablo Neira Ayuso --- include/libnftnl/chain.h | 1 + include/libnftnl/udata.h | 6 ++++++ include/linux/netfilter/nf_tables.h | 2 ++ src/chain.c | 31 +++++++++++++++++++++++++++++++ 4 files changed, 40 insertions(+) diff --git a/include/libnftnl/chain.h b/include/libnftnl/chain.h index 0e57a5a..f56e581 100644 --- a/include/libnftnl/chain.h +++ b/include/libnftnl/chain.h @@ -34,6 +34,7 @@ enum nftnl_chain_attr { NFTNL_CHAIN_DEVICES, NFTNL_CHAIN_FLAGS, NFTNL_CHAIN_ID, + NFTNL_CHAIN_USERDATA, __NFTNL_CHAIN_MAX }; #define NFTNL_CHAIN_MAX (__NFTNL_CHAIN_MAX - 1) diff --git a/include/libnftnl/udata.h b/include/libnftnl/udata.h index 2e38fcc..dbf3a60 100644 --- a/include/libnftnl/udata.h +++ b/include/libnftnl/udata.h @@ -15,6 +15,12 @@ enum nftnl_udata_table_types { }; #define NFTNL_UDATA_TABLE_MAX (__NFTNL_UDATA_TABLE_MAX - 1) +enum nftnl_udata_chain_types { + NFTNL_UDATA_CHAIN_COMMENT, + __NFTNL_UDATA_CHAIN_MAX +}; +#define NFTNL_UDATA_CHAIN_MAX (__NFTNL_UDATA_CHAIN_MAX - 1) + enum nftnl_udata_rule_types { NFTNL_UDATA_RULE_COMMENT, NFTNL_UDATA_RULE_EBTABLES_POLICY, diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h index 8099777..77d178a 100644 --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -197,6 +197,7 @@ enum nft_table_attributes { * @NFTA_CHAIN_TYPE: type name of the string (NLA_NUL_STRING) * @NFTA_CHAIN_COUNTERS: counter specification of the chain (NLA_NESTED: nft_counter_attributes) * @NFTA_CHAIN_FLAGS: chain flags + * @NFTA_CHAIN_USERDATA: user data (NLA_BINARY) */ enum nft_chain_attributes { NFTA_CHAIN_UNSPEC, @@ -211,6 +212,7 @@ enum nft_chain_attributes { NFTA_CHAIN_PAD, NFTA_CHAIN_FLAGS, NFTA_CHAIN_ID, + NFTA_CHAIN_USERDATA, __NFTA_CHAIN_MAX }; #define NFTA_CHAIN_MAX (__NFTA_CHAIN_MAX - 1) diff --git a/src/chain.c b/src/chain.c index 94efa90..aac9da6 100644 --- a/src/chain.c +++ b/src/chain.c @@ -51,6 +51,11 @@ struct nftnl_chain { uint32_t flags; uint32_t chain_id; + struct { + void *data; + uint32_t len; + } user; + struct list_head rule_list; }; @@ -125,6 +130,8 @@ void nftnl_chain_free(const struct nftnl_chain *c) xfree(c->type); if (c->flags & (1 << NFTNL_CHAIN_DEV)) xfree(c->dev); + if (c->flags & (1 << NFTNL_CHAIN_USERDATA)) + xfree(c->user.data); if (c->flags & (1 << NFTNL_CHAIN_DEVICES)) { for (i = 0; i < c->dev_array_len; i++) xfree(c->dev_array[i]); @@ -290,6 +297,16 @@ int nftnl_chain_set_data(struct nftnl_chain *c, uint16_t attr, case NFTNL_CHAIN_ID: memcpy(&c->chain_id, data, sizeof(c->chain_id)); break; + case NFTNL_CHAIN_USERDATA: + if (c->flags & (1 << NFTNL_CHAIN_USERDATA)) + xfree(c->user.data); + + c->user.data = malloc(data_len); + if (!c->user.data) + return -1; + memcpy(c->user.data, data, data_len); + c->user.len = data_len; + break; } c->flags |= (1 << attr); return 0; @@ -391,6 +408,9 @@ const void *nftnl_chain_get_data(const struct nftnl_chain *c, uint16_t attr, case NFTNL_CHAIN_ID: *data_len = sizeof(uint32_t); return &c->chain_id; + case NFTNL_CHAIN_USERDATA: + *data_len = c->user.len; + return c->user.data; } return NULL; } @@ -513,6 +533,8 @@ void nftnl_chain_nlmsg_build_payload(struct nlmsghdr *nlh, const struct nftnl_ch mnl_attr_put_u32(nlh, NFTA_CHAIN_FLAGS, htonl(c->chain_flags)); if (c->flags & (1 << NFTNL_CHAIN_ID)) mnl_attr_put_u32(nlh, NFTA_CHAIN_ID, htonl(c->chain_id)); + if (c->flags & (1 << NFTNL_CHAIN_USERDATA)) + mnl_attr_put(nlh, NFTA_CHAIN_USERDATA, c->user.len, c->user.data); } EXPORT_SYMBOL(nftnl_chain_rule_add); @@ -576,6 +598,10 @@ static int nftnl_chain_parse_attr_cb(const struct nlattr *attr, void *data) if (mnl_attr_validate(attr, MNL_TYPE_U64) < 0) abi_breakage(); break; + case NFTA_CHAIN_USERDATA: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) + abi_breakage(); + break; } tb[type] = attr; @@ -777,6 +803,11 @@ int nftnl_chain_nlmsg_parse(const struct nlmsghdr *nlh, struct nftnl_chain *c) c->chain_id = ntohl(mnl_attr_get_u32(tb[NFTA_CHAIN_ID])); c->flags |= (1 << NFTNL_CHAIN_ID); } + if (tb[NFTA_CHAIN_USERDATA]) { + nftnl_chain_set_data(c, NFTNL_CHAIN_USERDATA, + mnl_attr_get_payload(tb[NFTA_CHAIN_USERDATA]), + mnl_attr_get_payload_len(tb[NFTA_CHAIN_USERDATA])); + } c->family = nfg->nfgen_family; c->flags |= (1 << NFTNL_CHAIN_FAMILY); -- cgit v1.2.3