diff options
Diffstat (limited to 'src/expr')
| -rw-r--r-- | src/expr/bitwise.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/src/expr/bitwise.c b/src/expr/bitwise.c new file mode 100644 index 0000000..8275758 --- /dev/null +++ b/src/expr/bitwise.c @@ -0,0 +1,235 @@ +/* + * (C) 2012 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. + * + * This code has been sponsored by Sophos Astaro <http://www.sophos.com> + */ + +#include "internal.h" + +#include <stdio.h> +#include <stdint.h> +#include <string.h> /* for memcpy */ +#include <arpa/inet.h> +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftables/expr.h> +#include "data_reg.h" +#include "expr_ops.h" + +struct nft_expr_bitwise { + enum nft_registers sreg; + enum nft_registers dreg; + unsigned int len; + union nft_data_reg mask; + union nft_data_reg xor; +}; + +static int +nft_rule_expr_bitwise_set(struct nft_rule_expr *e, uint16_t type, + const void *data, size_t data_len) +{ + struct nft_expr_bitwise *bitwise = (struct nft_expr_bitwise *)e->data; + + switch(type) { + case NFT_EXPR_BITWISE_SREG: + bitwise->sreg = *((uint32_t *)data); + break; + case NFT_EXPR_BITWISE_DREG: + bitwise->dreg = *((uint32_t *)data); + break; + case NFT_EXPR_BITWISE_LEN: + bitwise->len = *((unsigned int *)data); + break; + case NFT_EXPR_BITWISE_MASK: + memcpy(&bitwise->mask.val, data, data_len); + bitwise->mask.len = data_len; + break; + case NFT_EXPR_BITWISE_XOR: + memcpy(&bitwise->xor.val, data, data_len); + bitwise->xor.len = data_len; + break; + default: + return -1; + } + return 0; +} + +static const void * +nft_rule_expr_bitwise_get(struct nft_rule_expr *e, uint16_t type, size_t *data_len) +{ + struct nft_expr_bitwise *bitwise = (struct nft_expr_bitwise *)e->data; + + switch(type) { + case NFT_EXPR_BITWISE_SREG: + if (e->flags & (1 << NFT_EXPR_BITWISE_SREG)) { + *data_len = sizeof(bitwise->sreg); + return &bitwise->sreg; + } + break; + case NFT_EXPR_BITWISE_DREG: + if (e->flags & (1 << NFT_EXPR_BITWISE_DREG)) { + *data_len = sizeof(bitwise->dreg); + return &bitwise->dreg; + } + break; + case NFT_EXPR_BITWISE_LEN: + if (e->flags & (1 << NFT_EXPR_BITWISE_LEN)) { + *data_len = sizeof(bitwise->len); + return &bitwise->len; + } + break; + case NFT_EXPR_BITWISE_MASK: + if (e->flags & (1 << NFT_EXPR_BITWISE_MASK)) { + *data_len = bitwise->mask.len; + return &bitwise->mask.val; + } + break; + case NFT_EXPR_BITWISE_XOR: + if (e->flags & (1 << NFT_EXPR_BITWISE_XOR)) { + *data_len = bitwise->xor.len; + return &bitwise->xor.val; + } + break; + default: + break; + } + return NULL; +} + +static int nft_rule_expr_bitwise_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_BITWISE_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_BITWISE_SREG: + case NFTA_BITWISE_DREG: + case NFTA_BITWISE_LEN: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + case NFTA_BITWISE_MASK: + case NFTA_BITWISE_XOR: + if (mnl_attr_validate(attr, MNL_TYPE_BINARY) < 0) { + perror("mnl_attr_validate"); + return MNL_CB_ERROR; + } + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nft_rule_expr_bitwise_build(struct nlmsghdr *nlh, struct nft_rule_expr *e) +{ + struct nft_expr_bitwise *bitwise = (struct nft_expr_bitwise *)e->data; + + if (e->flags & (1 << NFT_EXPR_BITWISE_SREG)) + mnl_attr_put_u32(nlh, NFTA_BITWISE_SREG, htonl(bitwise->sreg)); + if (e->flags & (1 << NFT_EXPR_BITWISE_DREG)) + mnl_attr_put_u32(nlh, NFTA_BITWISE_DREG, htonl(bitwise->dreg)); + if (e->flags & (1 << NFT_EXPR_BITWISE_LEN)) + mnl_attr_put_u32(nlh, NFTA_BITWISE_LEN, htonl(bitwise->len)); + if (e->flags & (1 << NFT_EXPR_BITWISE_MASK)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_BITWISE_MASK); + mnl_attr_put(nlh, NFTA_DATA_VALUE, bitwise->mask.len, + bitwise->mask.val); + mnl_attr_nest_end(nlh, nest); + } + if (e->flags & (1 << NFT_EXPR_BITWISE_XOR)) { + struct nlattr *nest; + + nest = mnl_attr_nest_start(nlh, NFTA_BITWISE_XOR); + mnl_attr_put(nlh, NFTA_DATA_VALUE, bitwise->xor.len, + bitwise->xor.val); + mnl_attr_nest_end(nlh, nest); + } +} + +static int +nft_rule_expr_bitwise_parse(struct nft_rule_expr *e, struct nlattr *attr) +{ + struct nft_expr_bitwise *bitwise = (struct nft_expr_bitwise *)e->data; + struct nlattr *tb[NFTA_BITWISE_MAX+1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nft_rule_expr_bitwise_cb, tb) < 0) + return -1; + + if (tb[NFTA_BITWISE_SREG]) { + bitwise->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_BITWISE_SREG])); + e->flags |= (1 << NFT_EXPR_BITWISE_SREG); + } + if (tb[NFTA_BITWISE_DREG]) { + bitwise->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_BITWISE_DREG])); + e->flags |= (1 << NFT_EXPR_BITWISE_DREG); + } + if (tb[NFTA_BITWISE_LEN]) { + bitwise->len = ntohl(mnl_attr_get_u32(tb[NFTA_BITWISE_LEN])); + e->flags |= (1 << NFT_EXPR_BITWISE_LEN); + } + if (tb[NFTA_BITWISE_MASK]) { + ret = nft_parse_data(&bitwise->mask, tb[NFTA_BITWISE_MASK], NULL); + e->flags |= (1 << NFTA_BITWISE_MASK); + } + if (tb[NFTA_BITWISE_XOR]) { + ret = nft_parse_data(&bitwise->xor, tb[NFTA_BITWISE_XOR], NULL); + e->flags |= (1 << NFTA_BITWISE_XOR); + } + + return ret; +} + +static int +nft_rule_expr_bitwise_snprintf(char *buf, size_t size, struct nft_rule_expr *e) +{ + struct nft_expr_bitwise *bitwise = (struct nft_expr_bitwise *)e->data; + int len = size, offset = 0, ret, i; + + ret = snprintf(buf, len, "sreg=%u dreg=%u ", + bitwise->sreg, bitwise->dreg); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + ret = snprintf(buf+offset, len, " mask="); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + for (i=0; i<bitwise->mask.len/sizeof(uint32_t); i++) { + ret = snprintf(buf+offset, len, "%.8x ", bitwise->mask.val[i]); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + ret = snprintf(buf+offset, len, " xor="); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + + for (i=0; i<bitwise->xor.len/sizeof(uint32_t); i++) { + ret = snprintf(buf+offset, len, "%.8x ", bitwise->xor.val[i]); + SNPRINTF_BUFFER_SIZE(ret, size, len, offset); + } + + return offset; +} + +struct expr_ops expr_ops_bitwise = { + .name = "bitwise", + .alloc_len = sizeof(struct nft_expr_bitwise), + .max_attr = NFTA_BITWISE_MAX, + .set = nft_rule_expr_bitwise_set, + .get = nft_rule_expr_bitwise_get, + .parse = nft_rule_expr_bitwise_parse, + .build = nft_rule_expr_bitwise_build, + .snprintf = nft_rule_expr_bitwise_snprintf, +}; 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