From: Pablo Neira Ayuso Date: Sun, 3 Dec 2017 21:05:54 +0100 Subject: [PATCH] expr: add flow offload expression This patch adds the new "flow_offload" expression to select what flows are offloaded to an existing flowtable. Signed-off-by: Pablo Neira Ayuso --- create mode 100644 src/expr/flow_offload.c --- a/include/libnftnl/expr.h +++ b/include/libnftnl/expr.h @@ -221,6 +221,10 @@ enum { }; enum { + NFTNL_EXPR_FLOW_TABLE_NAME = NFTNL_EXPR_BASE, +}; + +enum { NFTNL_EXPR_FWD_SREG_DEV = NFTNL_EXPR_BASE, }; --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -952,6 +952,17 @@ enum nft_ct_attributes { }; #define NFTA_CT_MAX (__NFTA_CT_MAX - 1) +/** + * enum nft_flow_attributes - ct offload expression attributes + * @NFTA_FLOW_TABLE_NAME: flow table name (NLA_STRING) + */ +enum nft_offload_attributes { + NFTA_FLOW_UNSPEC, + NFTA_FLOW_TABLE_NAME, + __NFTA_FLOW_MAX, +}; +#define NFTA_FLOW_MAX (__NFTA_FLOW_MAX - 1) + enum nft_limit_type { NFT_LIMIT_PKTS, NFT_LIMIT_PKT_BYTES --- a/src/Makefile.am +++ b/src/Makefile.am @@ -32,6 +32,7 @@ libnftnl_la_SOURCES = utils.c \ expr/data_reg.c \ expr/dup.c \ expr/exthdr.c \ + expr/flow_offload.c \ expr/fib.c \ expr/fwd.c \ expr/limit.c \ --- /dev/null +++ b/src/expr/flow_offload.c @@ -0,0 +1,184 @@ +#include "internal.h" + +#include +#include +#include /* for memcpy */ +#include +#include +#include +#include +#include +#include + +struct nftnl_expr_flow { + char *table_name; +}; + +static int nftnl_expr_flow_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_flow *flow = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_FLOW_TABLE_NAME: + flow->table_name = strdup((const char *)data); + if (!flow->table_name) + return -1; + break; + default: + return -1; + } + return 0; +} + +static const void *nftnl_expr_flow_get(const struct nftnl_expr *e, + uint16_t type, uint32_t *data_len) +{ + struct nftnl_expr_flow *flow = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_FLOW_TABLE_NAME: + *data_len = strlen(flow->table_name) + 1; + return flow->table_name; + } + return NULL; +} + +static int nftnl_expr_flow_cb(const struct nlattr *attr, void *data) +{ + const struct nlattr **tb = data; + int type = mnl_attr_get_type(attr); + + if (mnl_attr_type_valid(attr, NFTA_FLOW_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_FLOW_TABLE_NAME: + if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void nftnl_expr_flow_build(struct nlmsghdr *nlh, + const struct nftnl_expr *e) +{ + struct nftnl_expr_flow *flow = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_FLOW_TABLE_NAME)) + mnl_attr_put_strz(nlh, NFTA_FLOW_TABLE_NAME, flow->table_name); +} + +static int nftnl_expr_flow_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_flow *flow = nftnl_expr_data(e); + struct nlattr *tb[NFTA_FLOW_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_flow_cb, tb) < 0) + return -1; + + if (tb[NFTA_FLOW_TABLE_NAME]) { + flow->table_name = + strdup(mnl_attr_get_str(tb[NFTA_FLOW_TABLE_NAME])); + if (!flow->table_name) + return -1; + e->flags |= (1 << NFTNL_EXPR_FLOW_TABLE_NAME); + } + + return ret; +} + +static int +nftnl_expr_flow_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + const char *table_name; + + table_name = nftnl_jansson_parse_str(root, "flowtable", err); + if (table_name != NULL) + nftnl_expr_set_str(e, NFTNL_EXPR_FLOW_TABLE_NAME, table_name); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int nftnl_expr_flow_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_flow *l = nftnl_expr_data(e); + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_FLOW_TABLE_NAME)) + nftnl_buf_str(&b, type, l->table_name, SET); + + return nftnl_buf_done(&b); +} + +static int nftnl_expr_flow_snprintf_default(char *buf, size_t size, + const struct nftnl_expr *e) +{ + int remain = size, offset = 0, ret; + struct nftnl_expr_flow *l = nftnl_expr_data(e); + + ret = snprintf(buf, remain, "flowtable %s ", l->table_name); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + return offset; +} + +static int nftnl_expr_flow_snprintf(char *buf, size_t size, uint32_t type, + uint32_t flags, const struct nftnl_expr *e) +{ + switch(type) { + case NFTNL_OUTPUT_DEFAULT: + return nftnl_expr_flow_snprintf_default(buf, size, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_flow_export(buf, size, e, type); + default: + break; + } + return -1; +} + +static void nftnl_expr_flow_free(const struct nftnl_expr *e) +{ + struct nftnl_expr_flow *flow = nftnl_expr_data(e); + + xfree(flow->table_name); +} + +static bool nftnl_expr_flow_cmp(const struct nftnl_expr *e1, + const struct nftnl_expr *e2) +{ + struct nftnl_expr_flow *l1 = nftnl_expr_data(e1); + struct nftnl_expr_flow *l2 = nftnl_expr_data(e2); + bool eq = true; + + if (e1->flags & (1 << NFTNL_EXPR_FLOW_TABLE_NAME)) + eq &= !strcmp(l1->table_name, l2->table_name); + + return eq; +} + +struct expr_ops expr_ops_flow = { + .name = "flow_offload", + .alloc_len = sizeof(struct nftnl_expr_flow), + .max_attr = NFTA_FLOW_MAX, + .free = nftnl_expr_flow_free, + .cmp = nftnl_expr_flow_cmp, + .set = nftnl_expr_flow_set, + .get = nftnl_expr_flow_get, + .parse = nftnl_expr_flow_parse, + .build = nftnl_expr_flow_build, + .snprintf = nftnl_expr_flow_snprintf, + .json_parse = nftnl_expr_flow_json_parse, +}; --- a/src/expr_ops.c +++ b/src/expr_ops.c @@ -33,6 +33,7 @@ extern struct expr_ops expr_ops_target; extern struct expr_ops expr_ops_dynset; extern struct expr_ops expr_ops_hash; extern struct expr_ops expr_ops_fib; +extern struct expr_ops expr_ops_flow; static struct expr_ops expr_ops_notrack = { .name = "notrack", @@ -69,6 +70,7 @@ static struct expr_ops *expr_ops[] = { &expr_ops_hash, &expr_ops_fib, &expr_ops_objref, + &expr_ops_flow, NULL, };