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Diffstat (limited to '')
| -rw-r--r-- | src/expr/range.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/src/expr/range.c b/src/expr/range.c new file mode 100644 index 0000000..473add8 --- /dev/null +++ b/src/expr/range.c @@ -0,0 +1,217 @@ +/* + * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> + * + * 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 "internal.h" + +#include <stdio.h> +#include <stdint.h> +#include <string.h> +#include <arpa/inet.h> +#include <errno.h> + +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_range { + union nftnl_data_reg data_from; + union nftnl_data_reg data_to; + enum nft_registers sreg; + enum nft_range_ops op; +}; + +static int nftnl_expr_range_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_RANGE_SREG: + memcpy(&range->sreg, data, sizeof(range->sreg)); + break; + case NFTNL_EXPR_RANGE_OP: + memcpy(&range->op, data, sizeof(range->op)); + break; + case NFTNL_EXPR_RANGE_FROM_DATA: + memcpy(&range->data_from.val, data, data_len); + range->data_from.len = data_len; + break; + case NFTNL_EXPR_RANGE_TO_DATA: + memcpy(&range->data_to.val, data, data_len); + range->data_to.len = data_len; + break; + default: + return -1; + } + return 0; +} + +static const void *nftnl_expr_range_get(const struct nftnl_expr *e, + uint16_t type, uint32_t *data_len) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_RANGE_SREG: + *data_len = sizeof(range->sreg); + return &range->sreg; + case NFTNL_EXPR_RANGE_OP: + *data_len = sizeof(range->op); + return &range->op; + case NFTNL_EXPR_RANGE_FROM_DATA: + *data_len = range->data_from.len; + return &range->data_from.val; + case NFTNL_EXPR_RANGE_TO_DATA: + *data_len = range->data_to.len; + return &range->data_to.val; + } + return NULL; +} + +static int nftnl_expr_range_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_RANGE_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_RANGE_SREG: + case NFTA_RANGE_OP: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_RANGE_FROM_DATA: + case NFTA_RANGE_TO_DATA: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_range_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_RANGE_SREG)) + mnl_attr_put_u32(nlh, NFTA_RANGE_SREG, htonl(range->sreg)); + if (e->flags & (1 << NFTNL_EXPR_RANGE_OP)) + mnl_attr_put_u32(nlh, NFTA_RANGE_OP, htonl(range->op)); + if (e->flags & (1 << NFTNL_EXPR_RANGE_FROM_DATA)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_RANGE_FROM_DATA); + mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_from.len, + range->data_from.val); + mnl_attr_nest_end(nlh, nest); + } + if (e->flags & (1 << NFTNL_EXPR_RANGE_TO_DATA)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_RANGE_TO_DATA); + mnl_attr_put(nlh, NFTA_DATA_VALUE, range->data_to.len, + range->data_to.val); + mnl_attr_nest_end(nlh, nest); + } +} + +static int +nftnl_expr_range_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + struct nlattr *tb[NFTA_RANGE_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_range_cb, tb) < 0) + return -1; + + if (tb[NFTA_RANGE_SREG]) { + range->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_SREG])); + e->flags |= (1 << NFTA_RANGE_SREG); + } + if (tb[NFTA_RANGE_OP]) { + range->op = ntohl(mnl_attr_get_u32(tb[NFTA_RANGE_OP])); + e->flags |= (1 << NFTA_RANGE_OP); + } + if (tb[NFTA_RANGE_FROM_DATA]) { + ret = nftnl_parse_data(&range->data_from, + tb[NFTA_RANGE_FROM_DATA], NULL); + e->flags |= (1 << NFTA_RANGE_FROM_DATA); + } + if (tb[NFTA_RANGE_TO_DATA]) { + ret = nftnl_parse_data(&range->data_to, + tb[NFTA_RANGE_TO_DATA], NULL); + e->flags |= (1 << NFTA_RANGE_TO_DATA); + } + + return ret; +} + +static const char *expr_range_str[] = { + [NFT_RANGE_EQ] = "eq", + [NFT_RANGE_NEQ] = "neq", +}; + +static const char *range2str(uint32_t op) +{ + if (op > NFT_RANGE_NEQ) + return "unknown"; + + return expr_range_str[op]; +} + +static inline int nftnl_str2range(const char *op) +{ + if (strcmp(op, "eq") == 0) + return NFT_RANGE_EQ; + else if (strcmp(op, "neq") == 0) + return NFT_RANGE_NEQ; + else { + errno = EINVAL; + return -1; + } +} + +static int nftnl_expr_range_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_range *range = nftnl_expr_data(e); + int offset = 0, ret; + + ret = snprintf(buf, remain, "%s reg %u ", + range2str(range->op), range->sreg); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_from, + 0, DATA_VALUE); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + ret = nftnl_data_reg_snprintf(buf + offset, remain, &range->data_to, + 0, DATA_VALUE); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + return offset; +} + +struct expr_ops expr_ops_range = { + .name = "range", + .alloc_len = sizeof(struct nftnl_expr_range), + .max_attr = NFTA_RANGE_MAX, + .set = nftnl_expr_range_set, + .get = nftnl_expr_range_get, + .parse = nftnl_expr_range_parse, + .build = nftnl_expr_range_build, + .output = nftnl_expr_range_snprintf, +}; |