diff options
Diffstat (limited to 'src/expr/numgen.c')
| -rw-r--r-- | src/expr/numgen.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/src/expr/numgen.c b/src/expr/numgen.c new file mode 100644 index 0000000..0981d72 --- /dev/null +++ b/src/expr/numgen.c @@ -0,0 +1,251 @@ +/* + * (C) 2016 by Laura Garcia <nevola@gmail.com> + * + * 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 <stdio.h> +#include <stdint.h> +#include <string.h> +#include <arpa/inet.h> +#include <errno.h> +#include <linux/netfilter/nf_tables.h> + +#include "internal.h" +#include <libmnl/libmnl.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_ng { + enum nft_registers dreg; + unsigned int until; + enum nft_ng_type type; +}; + +static int +nftnl_expr_ng_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_NG_DREG: + ng->dreg = *((uint32_t *)data); + break; + case NFTNL_EXPR_NG_UNTIL: + ng->until = *((uint32_t *)data); + break; + case NFTNL_EXPR_NG_TYPE: + ng->type = *((uint32_t *)data); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_ng_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_NG_DREG: + *data_len = sizeof(ng->dreg); + return &ng->dreg; + case NFTNL_EXPR_NG_UNTIL: + *data_len = sizeof(ng->until); + return &ng->until; + case NFTNL_EXPR_NG_TYPE: + *data_len = sizeof(ng->type); + return &ng->type; + } + return NULL; +} + +static int nftnl_expr_ng_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_NG_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_NG_DREG: + case NFTA_NG_UNTIL: + case NFTA_NG_TYPE: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_ng_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_NG_DREG)) + mnl_attr_put_u32(nlh, NFTA_NG_DREG, htonl(ng->dreg)); + if (e->flags & (1 << NFTNL_EXPR_NG_UNTIL)) + mnl_attr_put_u32(nlh, NFTA_NG_UNTIL, htonl(ng->until)); + if (e->flags & (1 << NFTNL_EXPR_NG_TYPE)) + mnl_attr_put_u32(nlh, NFTA_NG_TYPE, htonl(ng->type)); +} + +static int +nftnl_expr_ng_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + struct nlattr *tb[NFTA_NG_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_ng_cb, tb) < 0) + return -1; + + if (tb[NFTA_NG_DREG]) { + ng->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_NG_DREG])); + e->flags |= (1 << NFTNL_EXPR_NG_DREG); + } + if (tb[NFTA_NG_UNTIL]) { + ng->until = ntohl(mnl_attr_get_u32(tb[NFTA_NG_UNTIL])); + e->flags |= (1 << NFTNL_EXPR_NG_UNTIL); + } + if (tb[NFTA_NG_TYPE]) { + ng->type = ntohl(mnl_attr_get_u32(tb[NFTA_NG_TYPE])); + e->flags |= (1 << NFTNL_EXPR_NG_TYPE); + } + + return ret; +} + +static int nftnl_expr_ng_json_parse(struct nftnl_expr *e, json_t *root, + struct nftnl_parse_err *err) +{ +#ifdef JSON_PARSING + uint32_t dreg, until, type; + + if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32, + &dreg, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_DREG, dreg); + + if (nftnl_jansson_parse_val(root, "until", NFTNL_TYPE_U32, + &until, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_UNTIL, until); + + if (nftnl_jansson_parse_val(root, "type", NFTNL_TYPE_U32, + &type, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_TYPE, type); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + + +static int nftnl_expr_ng_xml_parse(struct nftnl_expr *e, + mxml_node_t *tree, + struct nftnl_parse_err *err) +{ +#ifdef XML_PARSING + uint32_t dreg, until, type; + + if (nftnl_mxml_reg_parse(tree, "dreg", &dreg, MXML_DESCEND_FIRST, + NFTNL_XML_MAND, err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_DREG, dreg); + + if (nftnl_mxml_num_parse(tree, "until", MXML_DESCEND_FIRST, BASE_DEC, + &until, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_UNTIL, until); + + if (nftnl_mxml_num_parse(tree, "type", MXML_DESCEND_FIRST, BASE_DEC, + &type, NFTNL_TYPE_U32, NFTNL_XML_MAND, + err) == 0) + nftnl_expr_set_u32(e, NFTNL_EXPR_NG_TYPE, type); + + return 0; +#else + errno = EOPNOTSUPP; + return -1; +#endif +} + +static int +nftnl_expr_ng_snprintf_default(char *buf, size_t size, + const struct nftnl_expr *e) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + int len = size, offset = 0, ret; + + if (ng->type == NFT_NG_INCREMENTAL) { + ret = snprintf(buf, len, "reg %u = inc(%u)", ng->dreg, + ng->until); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + if (ng->type == NFT_NG_RANDOM) { + ret = snprintf(buf, len, "reg %u = random(%u)", ng->dreg, + ng->until); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + return offset; +} + +static int nftnl_expr_ng_export(char *buf, size_t size, + const struct nftnl_expr *e, int type) +{ + struct nftnl_expr_ng *ng = nftnl_expr_data(e); + + NFTNL_BUF_INIT(b, buf, size); + + if (e->flags & (1 << NFTNL_EXPR_NG_DREG)) + nftnl_buf_u32(&b, type, ng->dreg, DREG); + if (e->flags & (1 << NFTNL_EXPR_NG_UNTIL)) + nftnl_buf_u32(&b, type, ng->until, UNTIL); + if (e->flags & (1 << NFTNL_EXPR_NG_TYPE)) + nftnl_buf_u32(&b, type, ng->type, TYPE); + + return nftnl_buf_done(&b); +} + +static int +nftnl_expr_ng_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_ng_snprintf_default(buf, len, e); + case NFTNL_OUTPUT_XML: + case NFTNL_OUTPUT_JSON: + return nftnl_expr_ng_export(buf, len, e, type); + default: + break; + } + return -1; +} + +struct expr_ops expr_ops_ng = { + .name = "numgen", + .alloc_len = sizeof(struct nftnl_expr_ng), + .max_attr = NFTA_NG_MAX, + .set = nftnl_expr_ng_set, + .get = nftnl_expr_ng_get, + .parse = nftnl_expr_ng_parse, + .build = nftnl_expr_ng_build, + .snprintf = nftnl_expr_ng_snprintf, + .xml_parse = nftnl_expr_ng_xml_parse, + .json_parse = nftnl_expr_ng_json_parse, +}; 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