From c3394df0f547a542af95685fdf08dc46b22efa55 Mon Sep 17 00:00:00 2001 From: "Anders K. Pedersen" Date: Fri, 28 Oct 2016 05:55:33 +0000 Subject: src: introduce rt expression Introduce support for rt expression for routing related data as implemented in kernel. Signed-off-by: Anders K. Pedersen Signed-off-by: Pablo Neira Ayuso --- src/expr/rt.c | 243 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 243 insertions(+) create mode 100644 src/expr/rt.c (limited to 'src/expr') diff --git a/src/expr/rt.c b/src/expr/rt.c new file mode 100644 index 0000000..5088e66 --- /dev/null +++ b/src/expr/rt.c @@ -0,0 +1,243 @@ +/* + * Copyright (c) 2016 Anders K. Pedersen + * + * 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 "internal.h" +#include +#include +#include + +#ifndef NFT_RT_MAX +#define NFT_RT_MAX (NFT_RT_NEXTHOP6 + 1) +#endif + +struct nftnl_expr_rt { + enum nft_rt_keys key; + enum nft_registers dreg; +}; + +static int +nftnl_expr_rt_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_RT_KEY: + rt->key = *((uint32_t *)data); + break; + case NFTNL_EXPR_RT_DREG: + rt->dreg = *((uint32_t *)data); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_rt_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_RT_KEY: + *data_len = sizeof(rt->key); + return &rt->key; + case NFTNL_EXPR_RT_DREG: + *data_len = sizeof(rt->dreg); + return &rt->dreg; + } + return NULL; +} + +static int nftnl_expr_rt_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_RT_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_RT_KEY: + case NFTA_RT_DREG: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_rt_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_RT_KEY)) + mnl_attr_put_u32(nlh, NFTA_RT_KEY, htonl(rt->key)); + if (e->flags & (1 << NFTNL_EXPR_RT_DREG)) + mnl_attr_put_u32(nlh, NFTA_RT_DREG, htonl(rt->dreg)); +} + +static int +nftnl_expr_rt_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + struct nlattr *tb[NFTA_RT_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_rt_cb, tb) < 0) + return -1; + + if (tb[NFTA_RT_KEY]) { + rt->key = ntohl(mnl_attr_get_u32(tb[NFTA_RT_KEY])); + e->flags |= (1 << NFTNL_EXPR_RT_KEY); + } + if (tb[NFTA_RT_DREG]) { + rt->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_RT_DREG])); + e->flags |= (1 << NFTNL_EXPR_RT_DREG); + } + + return 0; +} + +static const char *rt_key2str_array[NFT_RT_MAX] = { + [NFT_RT_CLASSID] = "classid", + [NFT_RT_NEXTHOP4] = "nexthop4", + [NFT_RT_NEXTHOP6] = "nexthop6", +}; + +static const char *rt_key2str(uint8_t key) +{ + if (key < NFT_RT_MAX) + return rt_key2str_array[key]; + + return "unknown"; +} + +static inline int str2rt_key(const char *str) +{ + int i; + + for (i = 0; i < NFT_RT_MAX; i++) { + if (strcmp(str, rt_key2str_array[i]) == 0) + return i; + } + + errno = EINVAL; + return -1; +} + +static int nftnl_expr_rt_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + const char *val_str; + uint32_t reg; + int val32; + + val_str = nftnl_jansson_parse_str(root, "key", err); + if (val_str != NULL) { + val32 = str2rt_key(val_str); + if (val32 >= 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_RT_KEY, val32); + } + + if (nftnl_jansson_node_exist(root, "dreg")) { + if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32, ®, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_RT_DREG, reg); + } + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int +nftnl_expr_rt_snprintf_default(char *buf, size_t len, + const struct nftnl_expr *e) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_RT_DREG)) { + return snprintf(buf, len, "load %s => reg %u ", + rt_key2str(rt->key), rt->dreg); + } + return 0; +} + +static int nftnl_expr_rt_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_rt *rt = nftnl_expr_data(e); + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_RT_DREG)) + nftnl_buf_u32(&b, type, rt->dreg, DREG); + if (e->flags & (1 << NFTNL_EXPR_RT_KEY)) + nftnl_buf_str(&b, type, rt_key2str(rt->key), KEY); + + return nftnl_buf_done(&b); +} + +static int +nftnl_expr_rt_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_rt_snprintf_default(buf, len, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_rt_export(buf, len, e, type); + default: + break; + } + return -1; +} + +static bool nftnl_expr_rt_cmp(const struct nftnl_expr *e1, + const struct nftnl_expr *e2) +{ + struct nftnl_expr_rt *r1 = nftnl_expr_data(e1); + struct nftnl_expr_rt *r2 = nftnl_expr_data(e2); + bool eq = true; + + if (e1->flags & (1 << NFTNL_EXPR_RT_KEY)) + eq &= (r1->key == r2->key); + if (e1->flags & (1 << NFTNL_EXPR_RT_DREG)) + eq &= (r1->dreg == r2->dreg); + + return eq; +} + +struct expr_ops expr_ops_rt = { + .name = "rt", + .alloc_len = sizeof(struct nftnl_expr_rt), + .max_attr = NFTA_RT_MAX, + .cmp = nftnl_expr_rt_cmp, + .set = nftnl_expr_rt_set, + .get = nftnl_expr_rt_get, + .parse = nftnl_expr_rt_parse, + .build = nftnl_expr_rt_build, + .snprintf = nftnl_expr_rt_snprintf, + .json_parse = nftnl_expr_rt_json_parse, +}; 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