From 57c2b152c5f0866be5bf1acda2f341ba26ba9448 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?M=C3=A1t=C3=A9=20Eckl?= Date: Wed, 5 Sep 2018 11:16:44 +0200 Subject: src: add ipsec (xfrm) expression MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This allows matching on ipsec tunnel/beet addresses in xfrm state associated with a packet, ipsec request id and the SPI. Examples: ipsec in ip saddr 192.168.1.0/24 ipsec out ip6 daddr @endpoints ipsec in spi 1-65536 Joint work with Florian Westphal. Cc: Máté Eckl Signed-off-by: Florian Westphal --- src/xfrm.c | 120 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 120 insertions(+) create mode 100644 src/xfrm.c (limited to 'src/xfrm.c') diff --git a/src/xfrm.c b/src/xfrm.c new file mode 100644 index 00000000..0f5818c5 --- /dev/null +++ b/src/xfrm.c @@ -0,0 +1,120 @@ +/* + * XFRM (ipsec) expression + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#define XFRM_TEMPLATE_BE(__token, __dtype, __len) { \ + .token = (__token), \ + .dtype = (__dtype), \ + .len = (__len), \ + .byteorder = BYTEORDER_BIG_ENDIAN, \ +} + +#define XFRM_TEMPLATE_HE(__token, __dtype, __len) { \ + .token = (__token), \ + .dtype = (__dtype), \ + .len = (__len), \ + .byteorder = BYTEORDER_HOST_ENDIAN, \ +} + +const struct xfrm_template xfrm_templates[] = { + [NFT_XFRM_KEY_DADDR_IP4] = XFRM_TEMPLATE_BE("daddr", &ipaddr_type, 4 * BITS_PER_BYTE), + [NFT_XFRM_KEY_SADDR_IP4] = XFRM_TEMPLATE_BE("saddr", &ipaddr_type, 4 * BITS_PER_BYTE), + [NFT_XFRM_KEY_DADDR_IP6] = XFRM_TEMPLATE_BE("daddr", &ip6addr_type, 16 * BITS_PER_BYTE), + [NFT_XFRM_KEY_SADDR_IP6] = XFRM_TEMPLATE_BE("saddr", &ip6addr_type, 16 * BITS_PER_BYTE), + [NFT_XFRM_KEY_REQID] = XFRM_TEMPLATE_HE("reqid", &integer_type, 4 * BITS_PER_BYTE), + [NFT_XFRM_KEY_SPI] = XFRM_TEMPLATE_HE("spi", &integer_type, 4 * BITS_PER_BYTE), +}; + +static void xfrm_expr_print(const struct expr *expr, struct output_ctx *octx) +{ + switch (expr->xfrm.direction) { + case XFRM_POLICY_IN: + nft_print(octx, "ipsec in"); + break; + case XFRM_POLICY_OUT: + nft_print(octx, "ipsec out"); + break; + default: + nft_print(octx, "ipsec (unknown dir %d)", expr->xfrm.direction); + break; + } + + if (expr->xfrm.spnum) + nft_print(octx, " spnum %u", expr->xfrm.spnum); + + switch (expr->xfrm.key) { + case NFT_XFRM_KEY_DADDR_IP4: + case NFT_XFRM_KEY_SADDR_IP4: + nft_print(octx, " ip"); + break; + case NFT_XFRM_KEY_DADDR_IP6: + case NFT_XFRM_KEY_SADDR_IP6: + nft_print(octx, " ip6"); + break; + case NFT_XFRM_KEY_REQID: + case NFT_XFRM_KEY_SPI: + break; + default: + nft_print(octx, " (unknown key 0x%x)", expr->xfrm.key); + return; + } + + nft_print(octx, " %s", xfrm_templates[expr->xfrm.key].token); +} + +static bool xfrm_expr_cmp(const struct expr *e1, const struct expr *e2) +{ + return e1->xfrm.key == e2->xfrm.key && + e1->xfrm.direction == e2->xfrm.direction && + e1->xfrm.spnum == e2->xfrm.spnum; +} + +static void xfrm_expr_clone(struct expr *new, const struct expr *expr) +{ + memcpy(&new->xfrm, &expr->xfrm, sizeof(new->xfrm)); +} + +static const struct expr_ops xfrm_expr_ops = { + .type = EXPR_XFRM, + .name = "xfrm", + .print = xfrm_expr_print, + .json = xfrm_expr_json, + .cmp = xfrm_expr_cmp, + .clone = xfrm_expr_clone, +}; + +struct expr *xfrm_expr_alloc(const struct location *loc, + uint8_t direction, + uint8_t spnum, + enum nft_xfrm_keys key) +{ + struct expr *expr; + + expr = expr_alloc(loc, &xfrm_expr_ops, + xfrm_templates[key].dtype, + xfrm_templates[key].byteorder, + xfrm_templates[key].len); + + expr->xfrm.direction = direction; + expr->xfrm.spnum = spnum; + expr->xfrm.key = key; + + return expr; +} -- cgit v1.2.3