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Diffstat (limited to '')
| -rw-r--r-- | src/expr/fwd.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/expr/fwd.c b/src/expr/fwd.c new file mode 100644 index 0000000..51f6612 --- /dev/null +++ b/src/expr/fwd.c @@ -0,0 +1,162 @@ +/* + * (C) 2015 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 <stdio.h> +#include <stdint.h> +#include <string.h> +#include <arpa/inet.h> +#include <errno.h> +#include "internal.h" +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> +#include "expr_ops.h" +#include "data_reg.h" + +struct nftnl_expr_fwd { + enum nft_registers sreg_dev; + enum nft_registers sreg_addr; + uint32_t nfproto; +}; + +static int nftnl_expr_fwd_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_fwd *fwd = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_FWD_SREG_DEV: + memcpy(&fwd->sreg_dev, data, sizeof(fwd->sreg_dev)); + break; + case NFTNL_EXPR_FWD_SREG_ADDR: + memcpy(&fwd->sreg_addr, data, sizeof(fwd->sreg_addr)); + break; + case NFTNL_EXPR_FWD_NFPROTO: + memcpy(&fwd->nfproto, data, sizeof(fwd->nfproto)); + break; + default: + return -1; + } + return 0; +} + +static const void *nftnl_expr_fwd_get(const struct nftnl_expr *e, + uint16_t type, uint32_t *data_len) +{ + struct nftnl_expr_fwd *fwd = nftnl_expr_data(e); + + switch (type) { + case NFTNL_EXPR_FWD_SREG_DEV: + *data_len = sizeof(fwd->sreg_dev); + return &fwd->sreg_dev; + case NFTNL_EXPR_FWD_SREG_ADDR: + *data_len = sizeof(fwd->sreg_addr); + return &fwd->sreg_addr; + case NFTNL_EXPR_FWD_NFPROTO: + *data_len = sizeof(fwd->nfproto); + return &fwd->nfproto; + } + return NULL; +} + +static int nftnl_expr_fwd_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_FWD_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_FWD_SREG_DEV: + case NFTA_FWD_SREG_ADDR: + case NFTA_FWD_NFPROTO: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void nftnl_expr_fwd_build(struct nlmsghdr *nlh, + const struct nftnl_expr *e) +{ + struct nftnl_expr_fwd *fwd = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) + mnl_attr_put_u32(nlh, NFTA_FWD_SREG_DEV, htonl(fwd->sreg_dev)); + if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) + mnl_attr_put_u32(nlh, NFTA_FWD_SREG_ADDR, htonl(fwd->sreg_addr)); + if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) + mnl_attr_put_u32(nlh, NFTA_FWD_NFPROTO, htonl(fwd->nfproto)); +} + +static int nftnl_expr_fwd_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_fwd *fwd = nftnl_expr_data(e); + struct nlattr *tb[NFTA_FWD_MAX + 1] = {}; + int ret = 0; + + if (mnl_attr_parse_nested(attr, nftnl_expr_fwd_cb, tb) < 0) + return -1; + + if (tb[NFTA_FWD_SREG_DEV]) { + fwd->sreg_dev = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_DEV])); + e->flags |= (1 << NFTNL_EXPR_FWD_SREG_DEV); + } + if (tb[NFTA_FWD_SREG_ADDR]) { + fwd->sreg_addr = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_SREG_ADDR])); + e->flags |= (1 << NFTNL_EXPR_FWD_SREG_ADDR); + } + if (tb[NFTA_FWD_NFPROTO]) { + fwd->nfproto = ntohl(mnl_attr_get_u32(tb[NFTA_FWD_NFPROTO])); + e->flags |= (1 << NFTNL_EXPR_FWD_NFPROTO); + } + + return ret; +} + +static int nftnl_expr_fwd_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_fwd *fwd = nftnl_expr_data(e); + int offset = 0, ret; + + if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_DEV)) { + ret = snprintf(buf + offset, remain, "sreg_dev %u ", + fwd->sreg_dev); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (e->flags & (1 << NFTNL_EXPR_FWD_SREG_ADDR)) { + ret = snprintf(buf + offset, remain, "sreg_addr %u ", + fwd->sreg_addr); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + if (e->flags & (1 << NFTNL_EXPR_FWD_NFPROTO)) { + ret = snprintf(buf + offset, remain, "nfproto %u ", + fwd->nfproto); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +struct expr_ops expr_ops_fwd = { + .name = "fwd", + .alloc_len = sizeof(struct nftnl_expr_fwd), + .max_attr = NFTA_FWD_MAX, + .set = nftnl_expr_fwd_set, + .get = nftnl_expr_fwd_get, + .parse = nftnl_expr_fwd_parse, + .build = nftnl_expr_fwd_build, + .output = nftnl_expr_fwd_snprintf, +}; |