From a970963a2ad4411efcd7362c63f7d2e3bec5cbc2 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Wed, 14 Sep 2016 11:41:26 +0200 Subject: expr: add fib expression Allows to query fib for output interface and route type of a packets source or destination address. Scheduled for Linux 4.10. Signed-off-by: Florian Westphal --- include/libnftnl/expr.h | 6 + include/linux/netfilter/nf_tables.h | 36 +++++ src/Makefile.am | 1 + src/expr/fib.c | 273 ++++++++++++++++++++++++++++++++++++ src/expr_ops.c | 2 + 5 files changed, 318 insertions(+) create mode 100644 src/expr/fib.c diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h index 6245207..5cce49b 100644 --- a/include/libnftnl/expr.h +++ b/include/libnftnl/expr.h @@ -227,6 +227,12 @@ enum { NFTNL_EXPR_HASH_OFFSET, }; +enum { + NFTNL_EXPR_FIB_DREG = NFTNL_EXPR_BASE, + NFTNL_EXPR_FIB_RESULT, + NFTNL_EXPR_FIB_FLAGS, +}; + /* * Compat */ diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h index f396293..9e1541e 100644 --- a/include/linux/netfilter/nf_tables.h +++ b/include/linux/netfilter/nf_tables.h @@ -1130,6 +1130,42 @@ enum nft_gen_attributes { }; #define NFTA_GEN_MAX (__NFTA_GEN_MAX - 1) +/* + * enum nft_fib_attributes - nf_tables fib expression netlink attributes + * + * @NFTA_FIB_DREG: destination register (NLA_U32) + * @NFTA_FIB_RESULT: desired result (NLA_U32) + * @NFTA_FIB_FLAGS: flowi fields to initialize when querying the FIB (NLA_U32) + * + * The FIB expression performs a route lookup according + * to the packet data. + */ +enum nft_fib_attributes { + NFTA_FIB_UNSPEC, + NFTA_FIB_DREG, + NFTA_FIB_RESULT, + NFTA_FIB_FLAGS, + __NFTA_FIB_MAX +}; +#define NFTA_FIB_MAX (__NFTA_FIB_MAX - 1) + +enum nft_fib_result { + NFT_FIB_RESULT_UNSPEC, + NFT_FIB_RESULT_OIF, + NFT_FIB_RESULT_OIFNAME, + NFT_FIB_RESULT_ADDRTYPE, + __NFT_FIB_RESULT_MAX +}; +#define NFT_FIB_RESULT_MAX (__NFT_FIB_RESULT_MAX - 1) + +enum nft_fib_flags { + NFTA_FIB_F_SADDR = 1 << 0, /* look up src */ + NFTA_FIB_F_DADDR = 1 << 1, /* look up dst */ + NFTA_FIB_F_MARK = 1 << 2, /* use skb->mark */ + NFTA_FIB_F_IIF = 1 << 3, /* restrict to iif */ + NFTA_FIB_F_OIF = 1 << 4, /* restrict to oif */ +}; + /** * enum nft_trace_attributes - nf_tables trace netlink attributes * diff --git a/src/Makefile.am b/src/Makefile.am index 4b25470..e1e4144 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -30,6 +30,7 @@ libnftnl_la_SOURCES = utils.c \ expr/data_reg.c \ expr/dup.c \ expr/exthdr.c \ + expr/fib.c \ expr/fwd.c \ expr/limit.c \ expr/log.c \ diff --git a/src/expr/fib.c b/src/expr/fib.c new file mode 100644 index 0000000..9e63621 --- /dev/null +++ b/src/expr/fib.c @@ -0,0 +1,273 @@ +/* + * (C) 2016 Red Hat GmbH + * Author: Florian Westphal + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" +#include +#include +#include + +struct nftnl_expr_fib { + uint32_t flags; + uint32_t result; + enum nft_registers dreg; +}; + +static int +nftnl_expr_fib_set(struct nftnl_expr *e, uint16_t result, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + + switch (result) { + case NFTNL_EXPR_FIB_RESULT: + fib->result = *((uint32_t *)data); + break; + case NFTNL_EXPR_FIB_DREG: + fib->dreg = *((uint32_t *)data); + break; + case NFTNL_EXPR_FIB_FLAGS: + fib->flags = *((uint32_t *)data); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_fib_get(const struct nftnl_expr *e, uint16_t result, + uint32_t *data_len) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + + switch (result) { + case NFTNL_EXPR_FIB_RESULT: + *data_len = sizeof(fib->result); + return &fib->result; + case NFTNL_EXPR_FIB_DREG: + *data_len = sizeof(fib->dreg); + return &fib->dreg; + case NFTNL_EXPR_FIB_FLAGS: + *data_len = sizeof(fib->flags); + return &fib->flags; + } + return NULL; +} + +static int nftnl_expr_fib_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_FIB_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_FIB_RESULT: + case NFTA_FIB_DREG: + case NFTA_FIB_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_fib_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_FIB_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_FIB_FLAGS, htonl(fib->flags)); + if (e->flags & (1 << NFTNL_EXPR_FIB_RESULT)) + mnl_attr_put_u32(nlh, NFTA_FIB_RESULT, htonl(fib->result)); + if (e->flags & (1 << NFTNL_EXPR_FIB_DREG)) + mnl_attr_put_u32(nlh, NFTA_FIB_DREG, htonl(fib->dreg)); +} + +static int +nftnl_expr_fib_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + struct nlattr *tb[NFTA_FIB_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_fib_cb, tb) < 0) + return -1; + + if (tb[NFTA_FIB_RESULT]) { + fib->result = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_RESULT])); + e->flags |= (1 << NFTNL_EXPR_FIB_RESULT); + } + if (tb[NFTA_FIB_DREG]) { + fib->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_DREG])); + e->flags |= (1 << NFTNL_EXPR_FIB_DREG); + } + if (tb[NFTA_FIB_FLAGS]) { + fib->flags = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_FLAGS])); + e->flags |= (1 << NFTNL_EXPR_FIB_FLAGS); + } + return ret; +} + +static int nftnl_expr_fib_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + uint32_t result, flags, dreg; + + if (nftnl_jansson_parse_reg(root, "result", NFTNL_TYPE_U32, + &result, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_RESULT, result); + + if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32, + &dreg, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_DREG, dreg); + + if (nftnl_jansson_parse_val(root, "flags", NFTNL_TYPE_U32, + &flags, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_FLAGS, flags); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static const char *fib_type[NFT_FIB_RESULT_MAX + 1] = { + [NFT_FIB_RESULT_OIF] = "oif", + [NFT_FIB_RESULT_OIFNAME] = "oifname", + [NFT_FIB_RESULT_ADDRTYPE] = "type", +}; + +static const char *fib_type_str(enum nft_fib_result r) +{ + if (r <= NFT_FIB_RESULT_MAX) + return fib_type[r]; + + return "unknown"; +} + +static int +nftnl_expr_fib_snprintf_default(char *buf, size_t size, + const struct nftnl_expr *e) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + int len = size, offset = 0, ret, i; + uint32_t flags = fib->flags; + static const struct { + int bit; + const char *name; + } tab[] = { + { NFTA_FIB_F_SADDR, "saddr" }, + { NFTA_FIB_F_DADDR, "daddr" }, + { NFTA_FIB_F_MARK, "mark" }, + { NFTA_FIB_F_IIF, "iif" }, + { NFTA_FIB_F_OIF, "oif" }, + }; + + for (i = 0; i < (sizeof(tab) / sizeof(tab[0])); i++) { + if (flags & tab[i].bit) { + ret = snprintf(buf + offset, len, "%s ", tab[i].name); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + flags &= ~tab[i].bit; + if (flags) { + ret = snprintf(buf + offset, len, ". "); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + } + } + + if (flags) { + ret = snprintf(buf + offset, len, "unknown 0x%" PRIx32, flags); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + ret = snprintf(buf + offset, len, "%s => reg %d ", fib_type_str(fib->result), fib->dreg); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + return offset; +} + +static int nftnl_expr_fib_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_fib *fib = nftnl_expr_data(e); + + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_FIB_RESULT)) + nftnl_buf_u32(&b, type, fib->result, OP); + if (e->flags & (1 << NFTNL_EXPR_FIB_DREG)) + nftnl_buf_u32(&b, type, fib->dreg, DREG); + if (e->flags & (1 << NFTNL_EXPR_FIB_FLAGS)) + nftnl_buf_u32(&b, type, fib->flags, FLAGS); + + return nftnl_buf_done(&b); +} + +static int +nftnl_expr_fib_snprintf(char *buf, size_t len, uint32_t type, + uint32_t flags, const struct nftnl_expr *e) +{ + switch (type) { + case NFTNL_OUTPUT_DEFAULT: + return nftnl_expr_fib_snprintf_default(buf, len, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_fib_export(buf, len, e, type); + default: + break; + } + return -1; +} + +static bool nftnl_expr_fib_cmp(const struct nftnl_expr *e1, + const struct nftnl_expr *e2) +{ + struct nftnl_expr_fib *h1 = nftnl_expr_data(e1); + struct nftnl_expr_fib *h2 = nftnl_expr_data(e2); + bool eq = true; + + if (e1->flags & (1 << NFTNL_EXPR_FIB_RESULT)) + eq &= (h1->result == h2->result); + if (e1->flags & (1 << NFTNL_EXPR_FIB_DREG)) + eq &= (h1->dreg == h2->dreg); + if (e1->flags & (1 << NFTNL_EXPR_FIB_FLAGS)) + eq &= (h1->flags == h2->flags); + + return eq; +} + +struct expr_ops expr_ops_fib = { + .name = "fib", + .alloc_len = sizeof(struct nftnl_expr_fib), + .max_attr = NFTA_FIB_MAX, + .cmp = nftnl_expr_fib_cmp, + .set = nftnl_expr_fib_set, + .get = nftnl_expr_fib_get, + .parse = nftnl_expr_fib_parse, + .build = nftnl_expr_fib_build, + .snprintf = nftnl_expr_fib_snprintf, + .json_parse = nftnl_expr_fib_json_parse, +}; diff --git a/src/expr_ops.c b/src/expr_ops.c index a2de9cd..4d7d1fa 100644 --- a/src/expr_ops.c +++ b/src/expr_ops.c @@ -31,6 +31,7 @@ extern struct expr_ops expr_ops_quota; 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; static struct expr_ops expr_ops_notrack = { .name = "notrack", @@ -65,6 +66,7 @@ static struct expr_ops *expr_ops[] = { &expr_ops_target, &expr_ops_dynset, &expr_ops_hash, + &expr_ops_fib, NULL, }; -- cgit v1.2.3