expr: add fib expression

Allows to query fib for output interface and route type of a packets
source or destination address.

Scheduled for Linux 4.10.

Signed-off-by: Florian Westphal <fw@strlen.de>

diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index 6245207445de6c324926832e7b1586f9de152dd3..5cce49b4b05c5f92d7c05d5ba16a0d5dc8f186d5 100644 (file)
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -227,6 +227,12 @@ enum {
        NFTNL_EXPR_HASH_OFFSET,
 };
 
+enum {
+       NFTNL_EXPR_FIB_DREG     = NFTNL_EXPR_BASE,
+       NFTNL_EXPR_FIB_RESULT,
+       NFTNL_EXPR_FIB_FLAGS,
+};
+
 /*
  * Compat
  */

diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index f39629399ace7eaae9b8c9b033a095819f4198c7..9e1541ee27cf8a42a5357ee3fd73353fd83c4c55 100644 (file)
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -1130,6 +1130,42 @@ enum nft_gen_attributes {
 };
 #define NFTA_GEN_MAX           (__NFTA_GEN_MAX - 1)
 
+/*
+ * enum nft_fib_attributes - nf_tables fib expression netlink attributes
+ *
+ * @NFTA_FIB_DREG: destination register (NLA_U32)
+ * @NFTA_FIB_RESULT: desired result (NLA_U32)
+ * @NFTA_FIB_FLAGS: flowi fields to initialize when querying the FIB (NLA_U32)
+ *
+ * The FIB expression performs a route lookup according
+ * to the packet data.
+ */
+enum nft_fib_attributes {
+       NFTA_FIB_UNSPEC,
+       NFTA_FIB_DREG,
+       NFTA_FIB_RESULT,
+       NFTA_FIB_FLAGS,
+       __NFTA_FIB_MAX
+};
+#define NFTA_FIB_MAX (__NFTA_FIB_MAX - 1)
+
+enum nft_fib_result {
+       NFT_FIB_RESULT_UNSPEC,
+       NFT_FIB_RESULT_OIF,
+       NFT_FIB_RESULT_OIFNAME,
+       NFT_FIB_RESULT_ADDRTYPE,
+       __NFT_FIB_RESULT_MAX
+};
+#define NFT_FIB_RESULT_MAX     (__NFT_FIB_RESULT_MAX - 1)
+
+enum nft_fib_flags {
+       NFTA_FIB_F_SADDR        = 1 << 0,       /* look up src */
+       NFTA_FIB_F_DADDR        = 1 << 1,       /* look up dst */
+       NFTA_FIB_F_MARK         = 1 << 2,       /* use skb->mark */
+       NFTA_FIB_F_IIF          = 1 << 3,       /* restrict to iif */
+       NFTA_FIB_F_OIF          = 1 << 4,       /* restrict to oif */
+};
+
 /**
  * enum nft_trace_attributes - nf_tables trace netlink attributes
  *

diff --git a/src/Makefile.am b/src/Makefile.am
index 4b254706baf675308cf6a177f0c7c4c4590c386f..e1e4144526c33b1640b82db0bcfba9d27974dad5 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -30,6 +30,7 @@ libnftnl_la_SOURCES = utils.c         \
                      expr/data_reg.c   \
                      expr/dup.c        \
                      expr/exthdr.c     \
+                     expr/fib.c        \
                      expr/fwd.c        \
                      expr/limit.c      \
                      expr/log.c        \

diff --git a/src/expr/fib.c b/src/expr/fib.c
new file mode 100644 (file)
index 0000000..9e63621
--- /dev/null
+++ b/src/expr/fib.c
@@ -0,0 +1,273 @@
+/*
+ * (C) 2016 Red Hat GmbH
+ * Author: Florian Westphal <fw@strlen.de>
+ *
+ * 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 <inttypes.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_fib {
+       uint32_t                flags;
+       uint32_t                result;
+       enum nft_registers      dreg;
+};
+
+static int
+nftnl_expr_fib_set(struct nftnl_expr *e, uint16_t result,
+                   const void *data, uint32_t data_len)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+
+       switch (result) {
+       case NFTNL_EXPR_FIB_RESULT:
+               fib->result = *((uint32_t *)data);
+               break;
+       case NFTNL_EXPR_FIB_DREG:
+               fib->dreg = *((uint32_t *)data);
+               break;
+       case NFTNL_EXPR_FIB_FLAGS:
+               fib->flags = *((uint32_t *)data);
+               break;
+       default:
+               return -1;
+       }
+       return 0;
+}
+
+static const void *
+nftnl_expr_fib_get(const struct nftnl_expr *e, uint16_t result,
+                   uint32_t *data_len)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+
+       switch (result) {
+       case NFTNL_EXPR_FIB_RESULT:
+               *data_len = sizeof(fib->result);
+               return &fib->result;
+       case NFTNL_EXPR_FIB_DREG:
+               *data_len = sizeof(fib->dreg);
+               return &fib->dreg;
+       case NFTNL_EXPR_FIB_FLAGS:
+               *data_len = sizeof(fib->flags);
+               return &fib->flags;
+       }
+       return NULL;
+}
+
+static int nftnl_expr_fib_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_FIB_MAX) < 0)
+               return MNL_CB_OK;
+
+       switch (type) {
+       case NFTA_FIB_RESULT:
+       case NFTA_FIB_DREG:
+       case NFTA_FIB_FLAGS:
+               if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+                       abi_breakage();
+               break;
+       }
+
+       tb[type] = attr;
+       return MNL_CB_OK;
+}
+
+static void
+nftnl_expr_fib_build(struct nlmsghdr *nlh, const struct nftnl_expr *e)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+
+       if (e->flags & (1 << NFTNL_EXPR_FIB_FLAGS))
+               mnl_attr_put_u32(nlh, NFTA_FIB_FLAGS, htonl(fib->flags));
+       if (e->flags & (1 << NFTNL_EXPR_FIB_RESULT))
+               mnl_attr_put_u32(nlh, NFTA_FIB_RESULT, htonl(fib->result));
+       if (e->flags & (1 << NFTNL_EXPR_FIB_DREG))
+               mnl_attr_put_u32(nlh, NFTA_FIB_DREG, htonl(fib->dreg));
+}
+
+static int
+nftnl_expr_fib_parse(struct nftnl_expr *e, struct nlattr *attr)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+       struct nlattr *tb[NFTA_FIB_MAX+1] = {};
+       int ret = 0;
+
+       if (mnl_attr_parse_nested(attr, nftnl_expr_fib_cb, tb) < 0)
+               return -1;
+
+       if (tb[NFTA_FIB_RESULT]) {
+               fib->result = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_RESULT]));
+               e->flags |= (1 << NFTNL_EXPR_FIB_RESULT);
+       }
+       if (tb[NFTA_FIB_DREG]) {
+               fib->dreg = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_DREG]));
+               e->flags |= (1 << NFTNL_EXPR_FIB_DREG);
+       }
+       if (tb[NFTA_FIB_FLAGS]) {
+               fib->flags = ntohl(mnl_attr_get_u32(tb[NFTA_FIB_FLAGS]));
+               e->flags |= (1 << NFTNL_EXPR_FIB_FLAGS);
+       }
+       return ret;
+}
+
+static int nftnl_expr_fib_json_parse(struct nftnl_expr *e, json_t *root,
+                                     struct nftnl_parse_err *err)
+{
+#ifdef JSON_PARSING
+       uint32_t result, flags, dreg;
+
+       if (nftnl_jansson_parse_reg(root, "result", NFTNL_TYPE_U32,
+                                   &result, err) == 0)
+               nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_RESULT, result);
+
+       if (nftnl_jansson_parse_reg(root, "dreg", NFTNL_TYPE_U32,
+                                   &dreg, err) == 0)
+               nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_DREG, dreg);
+
+       if (nftnl_jansson_parse_val(root, "flags", NFTNL_TYPE_U32,
+                                   &flags, err) == 0)
+               nftnl_expr_set_u32(e, NFTNL_EXPR_FIB_FLAGS, flags);
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static const char *fib_type[NFT_FIB_RESULT_MAX + 1] = {
+       [NFT_FIB_RESULT_OIF] = "oif",
+       [NFT_FIB_RESULT_OIFNAME] = "oifname",
+       [NFT_FIB_RESULT_ADDRTYPE] = "type",
+};
+
+static const char *fib_type_str(enum nft_fib_result r)
+{
+       if (r <= NFT_FIB_RESULT_MAX)
+               return fib_type[r];
+
+       return "unknown";
+}
+
+static int
+nftnl_expr_fib_snprintf_default(char *buf, size_t size,
+                               const struct nftnl_expr *e)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+       int len = size, offset = 0, ret, i;
+       uint32_t flags = fib->flags;
+       static const struct {
+               int bit;
+               const char *name;
+       } tab[] = {
+               { NFTA_FIB_F_SADDR, "saddr" },
+               { NFTA_FIB_F_DADDR, "daddr" },
+               { NFTA_FIB_F_MARK, "mark" },
+               { NFTA_FIB_F_IIF, "iif" },
+               { NFTA_FIB_F_OIF, "oif" },
+       };
+
+       for (i = 0; i < (sizeof(tab) / sizeof(tab[0])); i++) {
+               if (flags & tab[i].bit) {
+                       ret = snprintf(buf + offset, len, "%s ", tab[i].name);
+                       SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+                       flags &= ~tab[i].bit;
+                       if (flags) {
+                               ret = snprintf(buf + offset, len, ". ");
+                               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+                       }
+               }
+       }
+
+       if (flags) {
+               ret = snprintf(buf + offset, len, "unknown 0x%" PRIx32, flags);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       ret = snprintf(buf + offset, len, "%s => reg %d ", fib_type_str(fib->result), fib->dreg);
+       SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+
+       return offset;
+}
+
+static int nftnl_expr_fib_export(char *buf, size_t size,
+                                 const struct nftnl_expr *e, int type)
+{
+       struct nftnl_expr_fib *fib = nftnl_expr_data(e);
+
+       NFTNL_BUF_INIT(b, buf, size);
+
+       if (e->flags & (1 << NFTNL_EXPR_FIB_RESULT))
+               nftnl_buf_u32(&b, type, fib->result, OP);
+       if (e->flags & (1 << NFTNL_EXPR_FIB_DREG))
+               nftnl_buf_u32(&b, type, fib->dreg, DREG);
+       if (e->flags & (1 << NFTNL_EXPR_FIB_FLAGS))
+               nftnl_buf_u32(&b, type, fib->flags, FLAGS);
+
+       return nftnl_buf_done(&b);
+}
+
+static int
+nftnl_expr_fib_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_fib_snprintf_default(buf, len, e);
+       case NFTNL_OUTPUT_XML:
+       case NFTNL_OUTPUT_JSON:
+               return nftnl_expr_fib_export(buf, len, e, type);
+       default:
+               break;
+       }
+       return -1;
+}
+
+static bool nftnl_expr_fib_cmp(const struct nftnl_expr *e1,
+                               const struct nftnl_expr *e2)
+{
+       struct nftnl_expr_fib *h1 = nftnl_expr_data(e1);
+       struct nftnl_expr_fib *h2 = nftnl_expr_data(e2);
+       bool eq = true;
+
+       if (e1->flags & (1 << NFTNL_EXPR_FIB_RESULT))
+               eq &= (h1->result == h2->result);
+       if (e1->flags & (1 << NFTNL_EXPR_FIB_DREG))
+               eq &= (h1->dreg == h2->dreg);
+       if (e1->flags & (1 << NFTNL_EXPR_FIB_FLAGS))
+               eq &= (h1->flags == h2->flags);
+
+       return eq;
+}
+
+struct expr_ops expr_ops_fib = {
+       .name           = "fib",
+       .alloc_len      = sizeof(struct nftnl_expr_fib),
+       .max_attr       = NFTA_FIB_MAX,
+       .cmp            = nftnl_expr_fib_cmp,
+       .set            = nftnl_expr_fib_set,
+       .get            = nftnl_expr_fib_get,
+       .parse          = nftnl_expr_fib_parse,
+       .build          = nftnl_expr_fib_build,
+       .snprintf       = nftnl_expr_fib_snprintf,
+       .json_parse     = nftnl_expr_fib_json_parse,
+};

diff --git a/src/expr_ops.c b/src/expr_ops.c
index a2de9cdd38fc0c047f3aaedf53d010405090a179..4d7d1fab4577fe5a949273e31a2a3a4ea30e80dd 100644 (file)
--- a/src/expr_ops.c
+++ b/src/expr_ops.c
@@ -31,6 +31,7 @@ extern struct expr_ops expr_ops_quota;
 extern struct expr_ops expr_ops_target;
 extern struct expr_ops expr_ops_dynset;
 extern struct expr_ops expr_ops_hash;
+extern struct expr_ops expr_ops_fib;
 
 static struct expr_ops expr_ops_notrack = {
        .name   = "notrack",
@@ -65,6 +66,7 @@ static struct expr_ops *expr_ops[] = {
        &expr_ops_target,
        &expr_ops_dynset,
        &expr_ops_hash,
+       &expr_ops_fib,
        NULL,
 };