diff options
Diffstat (limited to 'src/expr/ct.c')
| -rw-r--r-- | src/expr/ct.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/src/expr/ct.c b/src/expr/ct.c new file mode 100644 index 0000000..f4a2aea --- /dev/null +++ b/src/expr/ct.c @@ -0,0 +1,262 @@ +/* + * (C) 2012-2013 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 <stdio.h> +#include <string.h> +#include <stdint.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_ct { + enum nft_ct_keys key; + enum nft_registers dreg; + enum nft_registers sreg; + uint8_t dir; +}; + +#define IP_CT_DIR_ORIGINAL 0 +#define IP_CT_DIR_REPLY 1 + +static int +nftnl_expr_ct_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_ct *ct = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_CT_KEY: + memcpy(&ct->key, data, sizeof(ct->key)); + break; + case NFTNL_EXPR_CT_DIR: + memcpy(&ct->dir, data, sizeof(ct->dir)); + break; + case NFTNL_EXPR_CT_DREG: + memcpy(&ct->dreg, data, sizeof(ct->dreg)); + break; + case NFTNL_EXPR_CT_SREG: + memcpy(&ct->sreg, data, sizeof(ct->sreg)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_ct_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_ct *ct = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_CT_KEY: + *data_len = sizeof(ct->key); + return &ct->key; + case NFTNL_EXPR_CT_DIR: + *data_len = sizeof(ct->dir); + return &ct->dir; + case NFTNL_EXPR_CT_DREG: + *data_len = sizeof(ct->dreg); + return &ct->dreg; + case NFTNL_EXPR_CT_SREG: + *data_len = sizeof(ct->sreg); + return &ct->sreg; + } + return NULL; +} + +static int nftnl_expr_ct_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_CT_MAX) < 0) + return MNL_CB_OK; + + switch(type) { + case NFTA_CT_KEY: + case NFTA_CT_DREG: + case NFTA_CT_SREG: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_CT_DIRECTION: + if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_ct_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_ct *ct = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_CT_KEY)) + mnl_attr_put_u32(nlh, NFTA_CT_KEY, htonl(ct->key)); + if (e->flags & (1 << NFTNL_EXPR_CT_DREG)) + mnl_attr_put_u32(nlh, NFTA_CT_DREG, htonl(ct->dreg)); + if (e->flags & (1 << NFTNL_EXPR_CT_DIR)) + mnl_attr_put_u8(nlh, NFTA_CT_DIRECTION, ct->dir); + if (e->flags & (1 << NFTNL_EXPR_CT_SREG)) + mnl_attr_put_u32(nlh, NFTA_CT_SREG, htonl(ct->sreg)); +} + +static int +nftnl_expr_ct_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_ct *ct = nftnl_expr_data(e); + struct nlattr *tb[NFTA_CT_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_ct_cb, tb) < 0) + return -1; + + if (tb[NFTA_CT_KEY]) { + ct->key = ntohl(mnl_attr_get_u32(tb[NFTA_CT_KEY])); + e->flags |= (1 << NFTNL_EXPR_CT_KEY); + } + if (tb[NFTA_CT_DREG]) { + ct->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_DREG])); + e->flags |= (1 << NFTNL_EXPR_CT_DREG); + } + if (tb[NFTA_CT_SREG]) { + ct->sreg = ntohl(mnl_attr_get_u32(tb[NFTA_CT_SREG])); + e->flags |= (1 << NFTNL_EXPR_CT_SREG); + } + if (tb[NFTA_CT_DIRECTION]) { + ct->dir = mnl_attr_get_u8(tb[NFTA_CT_DIRECTION]); + e->flags |= (1 << NFTNL_EXPR_CT_DIR); + } + + return 0; +} + +static const char *ctkey2str_array[NFT_CT_MAX + 1] = { + [NFT_CT_STATE] = "state", + [NFT_CT_DIRECTION] = "direction", + [NFT_CT_STATUS] = "status", + [NFT_CT_MARK] = "mark", + [NFT_CT_SECMARK] = "secmark", + [NFT_CT_EXPIRATION] = "expiration", + [NFT_CT_HELPER] = "helper", + [NFT_CT_L3PROTOCOL] = "l3protocol", + [NFT_CT_PROTOCOL] = "protocol", + [NFT_CT_SRC] = "src", + [NFT_CT_DST] = "dst", + [NFT_CT_PROTO_SRC] = "proto_src", + [NFT_CT_PROTO_DST] = "proto_dst", + [NFT_CT_LABELS] = "label", + [NFT_CT_PKTS] = "packets", + [NFT_CT_BYTES] = "bytes", + [NFT_CT_AVGPKT] = "avgpkt", + [NFT_CT_ZONE] = "zone", + [NFT_CT_EVENTMASK] = "event", + [NFT_CT_SRC_IP] = "src_ip", + [NFT_CT_DST_IP] = "dst_ip", + [NFT_CT_SRC_IP6] = "src_ip6", + [NFT_CT_DST_IP6] = "dst_ip6", + [NFT_CT_ID] = "id", +}; + +static const char *ctkey2str(uint32_t ctkey) +{ + if (ctkey >= NFT_CT_MAX) + return "unknown"; + + return ctkey2str_array[ctkey]; +} + +static inline int str2ctkey(const char *ctkey) +{ + int i; + + for (i = 0; i < NFT_CT_MAX; i++) { + if (strcmp(ctkey2str_array[i], ctkey) == 0) + return i; + } + + return -1; +} + +static const char *ctdir2str(uint8_t ctdir) +{ + switch (ctdir) { + case IP_CT_DIR_ORIGINAL: + return "original"; + case IP_CT_DIR_REPLY: + return "reply"; + default: + return "unknown"; + } +} + +static inline int str2ctdir(const char *str, uint8_t *ctdir) +{ + if (strcmp(str, "original") == 0) { + *ctdir = IP_CT_DIR_ORIGINAL; + return 0; + } + + if (strcmp(str, "reply") == 0) { + *ctdir = IP_CT_DIR_REPLY; + return 0; + } + + return -1; +} + +static int +nftnl_expr_ct_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_ct *ct = nftnl_expr_data(e); + int ret, offset = 0; + + if (e->flags & (1 << NFTNL_EXPR_CT_SREG)) { + ret = snprintf(buf, remain, "set %s with reg %u ", + ctkey2str(ct->key), ct->sreg); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (e->flags & (1 << NFTNL_EXPR_CT_DREG)) { + ret = snprintf(buf, remain, "load %s => reg %u ", + ctkey2str(ct->key), ct->dreg); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + if (nftnl_expr_is_set(e, NFTNL_EXPR_CT_DIR)) { + ret = snprintf(buf + offset, remain, ", dir %s ", + ctdir2str(ct->dir)); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + + return offset; +} + +struct expr_ops expr_ops_ct = { + .name = "ct", + .alloc_len = sizeof(struct nftnl_expr_ct), + .max_attr = NFTA_CT_MAX, + .set = nftnl_expr_ct_set, + .get = nftnl_expr_ct_get, + .parse = nftnl_expr_ct_parse, + .build = nftnl_expr_ct_build, + .output = nftnl_expr_ct_snprintf, +}; |