expr: add support for matching tunnel metadata

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index fd0befc16f6e99579525069c188b7a741a4205d1..b0a0a851766d9928ccabe43e0d63e1d30275f4ea 100644 (file)
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -77,6 +77,11 @@ enum {
        NFTNL_EXPR_SOCKET_DREG,
 };
 
+enum {
+       NFTNL_EXPR_TUNNEL_KEY   = NFTNL_EXPR_BASE,
+       NFTNL_EXPR_TUNNEL_DREG,
+};
+
 enum {
        NFTNL_EXPR_CMP_SREG     = NFTNL_EXPR_BASE,
        NFTNL_EXPR_CMP_OP,

diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index 0450fc0731b57b4c0a1063752992654dc9f7a31b..6dc00c6f819b559b9d1ab8d9c7f7206ef2372db3 100644 (file)
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -1629,4 +1629,19 @@ enum nft_tunnel_key_attributes {
 };
 #define NFTA_TUNNEL_KEY_MAX    (__NFTA_TUNNEL_KEY_MAX - 1)
 
+enum nft_tunnel_keys {
+       NFT_TUNNEL_PATH,
+       NFT_TUNNEL_ID,
+       __NFT_TUNNEL_MAX
+};
+#define NFT_TUNNEL_MAX (__NFT_TUNNEL_MAX - 1)
+
+enum nft_tunnel_attributes {
+       NFTA_TUNNEL_UNSPEC,
+       NFTA_TUNNEL_KEY,
+       NFTA_TUNNEL_DREG,
+       __NFTA_TUNNEL_MAX
+};
+#define NFTA_TUNNEL_MAX        (__NFTA_TUNNEL_MAX - 1)
+
 #endif /* _LINUX_NF_TABLES_H */

diff --git a/src/Makefile.am b/src/Makefile.am
index 30511066cffe1445c6f7afe9da843428b91cd928..9a1a3c45ab7257fc6e863814ddf9512a67e1e11c 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -53,6 +53,7 @@ libnftnl_la_SOURCES = utils.c         \
                      expr/reject.c     \
                      expr/rt.c         \
                      expr/target.c     \
+                     expr/tunnel.c     \
                      expr/masq.c       \
                      expr/redir.c      \
                      expr/hash.c       \

diff --git a/src/expr/tunnel.c b/src/expr/tunnel.c
new file mode 100644 (file)
index 0000000..2067c35
--- /dev/null
+++ b/src/expr/tunnel.c
@@ -0,0 +1,192 @@
+/*
+ * (C) 2018 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.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.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_tunnel {
+       enum nft_tunnel_keys    key;
+       enum nft_registers      dreg;
+};
+
+static int nftnl_expr_tunnel_set(struct nftnl_expr *e, uint16_t type,
+                                const void *data, uint32_t data_len)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+       switch(type) {
+       case NFTNL_EXPR_TUNNEL_KEY:
+               tunnel->key = *((uint32_t *)data);
+               break;
+       case NFTNL_EXPR_TUNNEL_DREG:
+               tunnel->dreg = *((uint32_t *)data);
+               break;
+       default:
+               return -1;
+       }
+       return 0;
+}
+
+static const void *
+nftnl_expr_tunnel_get(const struct nftnl_expr *e, uint16_t type,
+                      uint32_t *data_len)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+       switch(type) {
+       case NFTNL_EXPR_TUNNEL_KEY:
+               *data_len = sizeof(tunnel->key);
+               return &tunnel->key;
+       case NFTNL_EXPR_TUNNEL_DREG:
+               *data_len = sizeof(tunnel->dreg);
+               return &tunnel->dreg;
+       }
+       return NULL;
+}
+
+static int nftnl_expr_tunnel_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_TUNNEL_MAX) < 0)
+               return MNL_CB_OK;
+
+       switch(type) {
+       case NFTA_TUNNEL_KEY:
+       case NFTA_TUNNEL_DREG:
+               if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+                       abi_breakage();
+               break;
+       }
+
+       tb[type] = attr;
+       return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_tunnel_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+       if (e->flags & (1 << NFTNL_EXPR_TUNNEL_KEY))
+               mnl_attr_put_u32(nlh, NFTA_TUNNEL_KEY, htonl(tunnel->key));
+       if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG))
+               mnl_attr_put_u32(nlh, NFTA_TUNNEL_DREG, htonl(tunnel->dreg));
+}
+
+static int
+nftnl_expr_tunnel_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+       struct nlattr *tb[NFTA_TUNNEL_MAX + 1] = {};
+
+       if (mnl_attr_parse_nested(attr, nftnl_expr_tunnel_cb, tb) < 0)
+               return -1;
+
+       if (tb[NFTA_TUNNEL_KEY]) {
+               tunnel->key = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_KEY]));
+               e->flags |= (1 << NFTNL_EXPR_TUNNEL_KEY);
+       }
+       if (tb[NFTA_TUNNEL_DREG]) {
+               tunnel->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_TUNNEL_DREG]));
+               e->flags |= (1 << NFTNL_EXPR_TUNNEL_DREG);
+       }
+
+       return 0;
+}
+
+static const char *tunnel_key2str_array[NFT_TUNNEL_MAX + 1] = {
+       [NFT_TUNNEL_PATH]       = "path",
+       [NFT_TUNNEL_ID]         = "id",
+};
+
+static const char *tunnel_key2str(uint8_t key)
+{
+       if (key <= NFT_TUNNEL_MAX)
+               return tunnel_key2str_array[key];
+
+       return "unknown";
+}
+
+static inline int str2tunnel_key(const char *str)
+{
+       int i;
+
+       for (i = 0; i <= NFT_TUNNEL_MAX; i++) {
+               if (strcmp(str, tunnel_key2str_array[i]) == 0)
+                       return i;
+       }
+
+       errno = EINVAL;
+       return -1;
+}
+
+static int
+nftnl_expr_tunnel_snprintf_default(char *buf, size_t len,
+                                const struct nftnl_expr *e)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+
+       if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG)) {
+               return snprintf(buf, len, "load %s => reg %u ",
+                               tunnel_key2str(tunnel->key), tunnel->dreg);
+       }
+       return 0;
+}
+
+static int nftnl_expr_tunnel_export(char *buf, size_t size,
+                                 const struct nftnl_expr *e, int type)
+{
+       struct nftnl_expr_tunnel *tunnel = nftnl_expr_data(e);
+       NFTNL_BUF_INIT(b, buf, size);
+
+       if (e->flags & (1 << NFTNL_EXPR_TUNNEL_DREG))
+               nftnl_buf_u32(&b, type, tunnel->dreg, DREG);
+       if (e->flags & (1 << NFTNL_EXPR_TUNNEL_KEY))
+               nftnl_buf_str(&b, type, tunnel_key2str(tunnel->key), KEY);
+
+       return nftnl_buf_done(&b);
+}
+
+static int
+nftnl_expr_tunnel_snprintf(char *buf, size_t len, uint32_t type,
+                        uint32_t flags, const struct nftnl_expr *e)
+{
+       switch (type) {
+       case NFTNL_OUTPUT_DEFAULT:
+               return nftnl_expr_tunnel_snprintf_default(buf, len, e);
+       case NFTNL_OUTPUT_XML:
+       case NFTNL_OUTPUT_JSON:
+               return nftnl_expr_tunnel_export(buf, len, e, type);
+       default:
+               break;
+       }
+       return -1;
+}
+
+struct expr_ops expr_ops_tunnel = {
+       .name           = "tunnel",
+       .alloc_len      = sizeof(struct nftnl_expr_tunnel),
+       .max_attr       = NFTA_TUNNEL_MAX,
+       .set            = nftnl_expr_tunnel_set,
+       .get            = nftnl_expr_tunnel_get,
+       .parse          = nftnl_expr_tunnel_parse,
+       .build          = nftnl_expr_tunnel_build,
+       .snprintf       = nftnl_expr_tunnel_snprintf,
+};

diff --git a/src/expr_ops.c b/src/expr_ops.c
index 23a9bcc7aad742d769737944dfc3a934ac0ec2ed..d418c3e8450163b4e0fd537bf915c2c4af2ff9c2 100644 (file)
--- a/src/expr_ops.c
+++ b/src/expr_ops.c
@@ -37,6 +37,7 @@ extern struct expr_ops expr_ops_hash;
 extern struct expr_ops expr_ops_fib;
 extern struct expr_ops expr_ops_flow;
 extern struct expr_ops expr_ops_socket;
+extern struct expr_ops expr_ops_tunnel;
 extern struct expr_ops expr_ops_osf;
 
 static struct expr_ops expr_ops_notrack = {
@@ -78,6 +79,7 @@ static struct expr_ops *expr_ops[] = {
        &expr_ops_objref,
        &expr_ops_flow,
        &expr_ops_socket,
+       &expr_ops_tunnel,
        &expr_ops_osf,
        NULL,
 };