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Diffstat (limited to '')
| -rw-r--r-- | src/expr/nat.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/expr/nat.c b/src/expr/nat.c new file mode 100644 index 0000000..ca727be --- /dev/null +++ b/src/expr/nat.c @@ -0,0 +1,278 @@ +/* + * (C) 2012-2014 Pablo Neira Ayuso <pablo@netfilter.org> + * (C) 2012 Intel Corporation + * + * 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. + * + * Authors: + * Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com> + */ + +#include "internal.h" + +#include <stdio.h> +#include <stdint.h> +#include <limits.h> +#include <string.h> +#include <errno.h> +#include <arpa/inet.h> +#include <libmnl/libmnl.h> +#include <linux/netfilter/nf_tables.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_nat { + enum nft_registers sreg_addr_min; + enum nft_registers sreg_addr_max; + enum nft_registers sreg_proto_min; + enum nft_registers sreg_proto_max; + int family; + enum nft_nat_types type; + uint32_t flags; +}; + +static int +nftnl_expr_nat_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_nat *nat = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_NAT_TYPE: + memcpy(&nat->type, data, sizeof(nat->type)); + break; + case NFTNL_EXPR_NAT_FAMILY: + memcpy(&nat->family, data, sizeof(nat->family)); + break; + case NFTNL_EXPR_NAT_REG_ADDR_MIN: + memcpy(&nat->sreg_addr_min, data, sizeof(nat->sreg_addr_min)); + break; + case NFTNL_EXPR_NAT_REG_ADDR_MAX: + memcpy(&nat->sreg_addr_max, data, sizeof(nat->sreg_addr_max)); + break; + case NFTNL_EXPR_NAT_REG_PROTO_MIN: + memcpy(&nat->sreg_proto_min, data, sizeof(nat->sreg_proto_min)); + break; + case NFTNL_EXPR_NAT_REG_PROTO_MAX: + memcpy(&nat->sreg_proto_max, data, sizeof(nat->sreg_proto_max)); + break; + case NFTNL_EXPR_NAT_FLAGS: + memcpy(&nat->flags, data, sizeof(nat->flags)); + break; + default: + return -1; + } + + return 0; +} + +static const void * +nftnl_expr_nat_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_nat *nat = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_NAT_TYPE: + *data_len = sizeof(nat->type); + return &nat->type; + case NFTNL_EXPR_NAT_FAMILY: + *data_len = sizeof(nat->family); + return &nat->family; + case NFTNL_EXPR_NAT_REG_ADDR_MIN: + *data_len = sizeof(nat->sreg_addr_min); + return &nat->sreg_addr_min; + case NFTNL_EXPR_NAT_REG_ADDR_MAX: + *data_len = sizeof(nat->sreg_addr_max); + return &nat->sreg_addr_max; + case NFTNL_EXPR_NAT_REG_PROTO_MIN: + *data_len = sizeof(nat->sreg_proto_min); + return &nat->sreg_proto_min; + case NFTNL_EXPR_NAT_REG_PROTO_MAX: + *data_len = sizeof(nat->sreg_proto_max); + return &nat->sreg_proto_max; + case NFTNL_EXPR_NAT_FLAGS: + *data_len = sizeof(nat->flags); + return &nat->flags; + } + return NULL; +} + +static int nftnl_expr_nat_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_NAT_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_NAT_TYPE: + case NFTA_NAT_FAMILY: + case NFTA_NAT_REG_ADDR_MIN: + case NFTA_NAT_REG_ADDR_MAX: + case NFTA_NAT_REG_PROTO_MIN: + case NFTA_NAT_REG_PROTO_MAX: + case NFTA_NAT_FLAGS: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static int +nftnl_expr_nat_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_nat *nat = nftnl_expr_data(e); + struct nlattr *tb[NFTA_NAT_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_nat_cb, tb) < 0) + return -1; + + if (tb[NFTA_NAT_TYPE]) { + nat->type = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_TYPE])); + e->flags |= (1 << NFTNL_EXPR_NAT_TYPE); + } + if (tb[NFTA_NAT_FAMILY]) { + nat->family = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_FAMILY])); + e->flags |= (1 << NFTNL_EXPR_NAT_FAMILY); + } + if (tb[NFTA_NAT_REG_ADDR_MIN]) { + nat->sreg_addr_min = + ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_ADDR_MIN])); + e->flags |= (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN); + } + if (tb[NFTA_NAT_REG_ADDR_MAX]) { + nat->sreg_addr_max = + ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_ADDR_MAX])); + e->flags |= (1 << NFTNL_EXPR_NAT_REG_ADDR_MAX); + } + if (tb[NFTA_NAT_REG_PROTO_MIN]) { + nat->sreg_proto_min = + ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_PROTO_MIN])); + e->flags |= (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN); + } + if (tb[NFTA_NAT_REG_PROTO_MAX]) { + nat->sreg_proto_max = + ntohl(mnl_attr_get_u32(tb[NFTA_NAT_REG_PROTO_MAX])); + e->flags |= (1 << NFTNL_EXPR_NAT_REG_PROTO_MAX); + } + if (tb[NFTA_NAT_FLAGS]) { + nat->flags = ntohl(mnl_attr_get_u32(tb[NFTA_NAT_FLAGS])); + e->flags |= (1 << NFTNL_EXPR_NAT_FLAGS); + } + + return 0; +} + +static void +nftnl_expr_nat_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_nat *nat = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_NAT_TYPE)) + mnl_attr_put_u32(nlh, NFTA_NAT_TYPE, htonl(nat->type)); + if (e->flags & (1 << NFTNL_EXPR_NAT_FAMILY)) + mnl_attr_put_u32(nlh, NFTA_NAT_FAMILY, htonl(nat->family)); + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN)) + mnl_attr_put_u32(nlh, NFTA_NAT_REG_ADDR_MIN, + htonl(nat->sreg_addr_min)); + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MAX)) + mnl_attr_put_u32(nlh, NFTA_NAT_REG_ADDR_MAX, + htonl(nat->sreg_addr_max)); + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN)) + mnl_attr_put_u32(nlh, NFTA_NAT_REG_PROTO_MIN, + htonl(nat->sreg_proto_min)); + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MAX)) + mnl_attr_put_u32(nlh, NFTA_NAT_REG_PROTO_MAX, + htonl(nat->sreg_proto_max)); + if (e->flags & (1 << NFTNL_EXPR_NAT_FLAGS)) + mnl_attr_put_u32(nlh, NFTA_NAT_FLAGS, htonl(nat->flags)); +} + +static inline const char *nat2str(uint16_t nat) +{ + switch (nat) { + case NFT_NAT_SNAT: + return "snat"; + case NFT_NAT_DNAT: + return "dnat"; + default: + return "unknown"; + } +} + +static inline int nftnl_str2nat(const char *nat) +{ + if (strcmp(nat, "snat") == 0) + return NFT_NAT_SNAT; + else if (strcmp(nat, "dnat") == 0) + return NFT_NAT_DNAT; + else { + errno = EINVAL; + return -1; + } +} + +static int +nftnl_expr_nat_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_nat *nat = nftnl_expr_data(e); + int offset = 0, ret = 0; + + ret = snprintf(buf, remain, "%s ", nat2str(nat->type)); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + ret = snprintf(buf + offset, remain, "%s ", + nftnl_family2str(nat->family)); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MIN)) { + ret = snprintf(buf + offset, remain, + "addr_min reg %u ", nat->sreg_addr_min); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_ADDR_MAX)) { + ret = snprintf(buf + offset, remain, + "addr_max reg %u ", nat->sreg_addr_max); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MIN)) { + ret = snprintf(buf + offset, remain, + "proto_min reg %u ", nat->sreg_proto_min); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_NAT_REG_PROTO_MAX)) { + ret = snprintf(buf + offset, remain, + "proto_max reg %u ", nat->sreg_proto_max); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_NAT_FLAGS)) { + ret = snprintf(buf + offset, remain, "flags 0x%x ", nat->flags); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +struct expr_ops expr_ops_nat = { + .name = "nat", + .alloc_len = sizeof(struct nftnl_expr_nat), + .max_attr = NFTA_NAT_MAX, + .set = nftnl_expr_nat_set, + .get = nftnl_expr_nat_get, + .parse = nftnl_expr_nat_parse, + .build = nftnl_expr_nat_build, + .output = nftnl_expr_nat_snprintf, +}; 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