diff options
Diffstat (limited to 'src/expr/xfrm.c')
| -rw-r--r-- | src/expr/xfrm.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/src/expr/xfrm.c b/src/expr/xfrm.c new file mode 100644 index 0000000..2db00d5 --- /dev/null +++ b/src/expr/xfrm.c @@ -0,0 +1,200 @@ +/* + * 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 <string.h> +#include <stdint.h> +#include <arpa/inet.h> +#include <errno.h> +#include <linux/netfilter/nf_tables.h> +#include <linux/xfrm.h> + +#include "internal.h" +#include <libmnl/libmnl.h> +#include <libnftnl/expr.h> +#include <libnftnl/rule.h> + +struct nftnl_expr_xfrm { + enum nft_registers dreg; + enum nft_xfrm_keys key; + uint32_t spnum; + uint8_t dir; +}; + +static int +nftnl_expr_xfrm_set(struct nftnl_expr *e, uint16_t type, + const void *data, uint32_t data_len) +{ + struct nftnl_expr_xfrm *x = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_XFRM_KEY: + memcpy(&x->key, data, sizeof(x->key)); + break; + case NFTNL_EXPR_XFRM_DIR: + memcpy(&x->dir, data, sizeof(x->dir)); + break; + case NFTNL_EXPR_XFRM_SPNUM: + memcpy(&x->spnum, data, sizeof(x->spnum)); + break; + case NFTNL_EXPR_XFRM_DREG: + memcpy(&x->dreg, data, sizeof(x->dreg)); + break; + default: + return -1; + } + return 0; +} + +static const void * +nftnl_expr_xfrm_get(const struct nftnl_expr *e, uint16_t type, + uint32_t *data_len) +{ + struct nftnl_expr_xfrm *x = nftnl_expr_data(e); + + switch(type) { + case NFTNL_EXPR_XFRM_KEY: + *data_len = sizeof(x->key); + return &x->key; + case NFTNL_EXPR_XFRM_DIR: + *data_len = sizeof(x->dir); + return &x->dir; + case NFTNL_EXPR_XFRM_SPNUM: + *data_len = sizeof(x->spnum); + return &x->spnum; + case NFTNL_EXPR_XFRM_DREG: + *data_len = sizeof(x->dreg); + return &x->dreg; + } + return NULL; +} + +static int nftnl_expr_xfrm_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_XFRM_MAX) < 0) + return MNL_CB_OK; + + switch (type) { + case NFTA_XFRM_DREG: + case NFTA_XFRM_KEY: + case NFTA_XFRM_SPNUM: + if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) + abi_breakage(); + break; + case NFTA_XFRM_DIR: + if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0) + abi_breakage(); + break; + } + + tb[type] = attr; + return MNL_CB_OK; +} + +static void +nftnl_expr_xfrm_build(struct nlmsghdr *nlh, const struct nftnl_expr *e) +{ + struct nftnl_expr_xfrm *x = nftnl_expr_data(e); + + if (e->flags & (1 << NFTNL_EXPR_XFRM_KEY)) + mnl_attr_put_u32(nlh, NFTA_XFRM_KEY, htonl(x->key)); + if (e->flags & (1 << NFTNL_EXPR_XFRM_DIR)) + mnl_attr_put_u8(nlh, NFTA_XFRM_DIR, x->dir); + if (e->flags & (1 << NFTNL_EXPR_XFRM_SPNUM)) + mnl_attr_put_u32(nlh, NFTA_XFRM_SPNUM, htonl(x->spnum)); + if (e->flags & (1 << NFTNL_EXPR_XFRM_DREG)) + mnl_attr_put_u32(nlh, NFTA_XFRM_DREG, htonl(x->dreg)); +} + +static int +nftnl_expr_xfrm_parse(struct nftnl_expr *e, struct nlattr *attr) +{ + struct nftnl_expr_xfrm *x = nftnl_expr_data(e); + struct nlattr *tb[NFTA_XFRM_MAX+1] = {}; + + if (mnl_attr_parse_nested(attr, nftnl_expr_xfrm_cb, tb) < 0) + return -1; + + if (tb[NFTA_XFRM_KEY]) { + x->key = ntohl(mnl_attr_get_u32(tb[NFTA_XFRM_KEY])); + e->flags |= (1 << NFTNL_EXPR_XFRM_KEY); + } + if (tb[NFTA_XFRM_DIR]) { + x->dir = mnl_attr_get_u8(tb[NFTA_XFRM_DIR]); + e->flags |= (1 << NFTNL_EXPR_XFRM_DIR); + } + if (tb[NFTA_XFRM_SPNUM]) { + x->spnum = ntohl(mnl_attr_get_u32(tb[NFTA_XFRM_SPNUM])); + e->flags |= (1 << NFTNL_EXPR_XFRM_SPNUM); + } + if (tb[NFTA_XFRM_DREG]) { + x->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_XFRM_DREG])); + e->flags |= (1 << NFTNL_EXPR_XFRM_DREG); + } + return 0; +} + +static const char *xfrmkey2str_array[] = { + [NFT_XFRM_KEY_DADDR_IP4] = "daddr4", + [NFT_XFRM_KEY_SADDR_IP4] = "saddr4", + [NFT_XFRM_KEY_DADDR_IP6] = "daddr6", + [NFT_XFRM_KEY_SADDR_IP6] = "saddr6", + [NFT_XFRM_KEY_REQID] = "reqid", + [NFT_XFRM_KEY_SPI] = "spi", +}; + +static const char *xfrmkey2str(uint32_t key) +{ + if (key >= sizeof(xfrmkey2str_array) / sizeof(xfrmkey2str_array[0])) + return "unknown"; + + return xfrmkey2str_array[key]; +} + +static const char *xfrmdir2str_array[] = { + [XFRM_POLICY_IN] = "in", + [XFRM_POLICY_OUT] = "out", +}; + +static const char *xfrmdir2str(uint8_t dir) +{ + if (dir >= sizeof(xfrmdir2str_array) / sizeof(xfrmdir2str_array[0])) + return "unknown"; + + return xfrmdir2str_array[dir]; +} + +static int +nftnl_expr_xfrm_snprintf(char *buf, size_t remain, + uint32_t flags, const struct nftnl_expr *e) +{ + struct nftnl_expr_xfrm *x = nftnl_expr_data(e); + int ret, offset = 0; + + if (e->flags & (1 << NFTNL_EXPR_XFRM_DREG)) { + ret = snprintf(buf, remain, "load %s %u %s => reg %u ", + xfrmdir2str(x->dir), + x->spnum, + xfrmkey2str(x->key), x->dreg); + SNPRINTF_BUFFER_SIZE(ret, remain, offset); + } + return offset; +} + +struct expr_ops expr_ops_xfrm = { + .name = "xfrm", + .alloc_len = sizeof(struct nftnl_expr_xfrm), + .max_attr = NFTA_XFRM_MAX, + .set = nftnl_expr_xfrm_set, + .get = nftnl_expr_xfrm_get, + .parse = nftnl_expr_xfrm_parse, + .build = nftnl_expr_xfrm_build, + .output = nftnl_expr_xfrm_snprintf, +}; 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