src: add support for nft_redir expression

This patch adds support for the new nft_redir expression.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/libnftnl/expr.h b/include/libnftnl/expr.h
index 0505dec2296e2083b3e052a8206d574b665646a3..9f25993c91c2703c5a93fab86a9cba17f54c68da 100644 (file)
--- a/include/libnftnl/expr.h
+++ b/include/libnftnl/expr.h
@@ -161,6 +161,12 @@ enum {
        NFT_EXPR_MASQ_FLAGS     = NFT_RULE_EXPR_ATTR_BASE,
 };
 
+enum {
+       NFT_EXPR_REDIR_REG_PROTO_MIN    = NFT_RULE_EXPR_ATTR_BASE,
+       NFT_EXPR_REDIR_REG_PROTO_MAX,
+       NFT_EXPR_REDIR_FLAGS,
+};
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

diff --git a/include/linux/netfilter/nf_tables.h b/include/linux/netfilter/nf_tables.h
index b72ccfeaf86527e12b61230597798d1cb902f949..bb2131563d4147c731095f0c8e39340dc3a19942 100644 (file)
--- a/include/linux/netfilter/nf_tables.h
+++ b/include/linux/netfilter/nf_tables.h
@@ -749,12 +749,33 @@ enum nft_queue_attributes {
  *
  * @NFT_REJECT_ICMP_UNREACH: reject using ICMP unreachable
  * @NFT_REJECT_TCP_RST: reject using TCP RST
+ * @NFT_REJECT_ICMPX_UNREACH: abstracted ICMP unreachable for bridge and inet
  */
 enum nft_reject_types {
        NFT_REJECT_ICMP_UNREACH,
        NFT_REJECT_TCP_RST,
+       NFT_REJECT_ICMPX_UNREACH,
 };
 
+/**
+ * enum nft_reject_code - Generic reject codes for IPv4/IPv6
+ *
+ * @NFT_REJECT_ICMPX_NO_ROUTE: no route to host / network unreachable
+ * @NFT_REJECT_ICMPX_PORT_UNREACH: port unreachable
+ * @NFT_REJECT_ICMPX_HOST_UNREACH: host unreachable
+ * @NFT_REJECT_ICMPX_ADMIN_PROHIBITED: administratively prohibited
+ *
+ * These codes are mapped to real ICMP and ICMPv6 codes.
+ */
+enum nft_reject_inet_code {
+       NFT_REJECT_ICMPX_NO_ROUTE       = 0,
+       NFT_REJECT_ICMPX_PORT_UNREACH,
+       NFT_REJECT_ICMPX_HOST_UNREACH,
+       NFT_REJECT_ICMPX_ADMIN_PROHIBITED,
+       __NFT_REJECT_ICMPX_MAX
+};
+#define NFT_REJECT_ICMPX_MAX   (__NFT_REJECT_ICMPX_MAX + 1)
+
 /**
  * enum nft_reject_attributes - nf_tables reject expression netlink attributes
  *
@@ -816,6 +837,22 @@ enum nft_masq_attributes {
 };
 #define NFTA_MASQ_MAX          (__NFTA_MASQ_MAX - 1)
 
+/**
+ * enum nft_redir_attributes - nf_tables redirect expression netlink attributes
+ *
+ * @NFTA_REDIR_REG_PROTO_MIN: source register of proto range start (NLA_U32: nft_registers)
+ * @NFTA_REDIR_REG_PROTO_MAX: source register of proto range end (NLA_U32: nft_registers)
+ * @NFTA_REDIR_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)
+ */
+enum nft_redir_attributes {
+       NFTA_REDIR_UNSPEC,
+       NFTA_REDIR_REG_PROTO_MIN,
+       NFTA_REDIR_REG_PROTO_MAX,
+       NFTA_REDIR_FLAGS,
+       __NFTA_REDIR_MAX
+};
+#define NFTA_REDIR_MAX         (__NFTA_REDIR_MAX - 1)
+
 /**
  * enum nft_gen_attributes - nf_tables ruleset generation attributes
  *

diff --git a/src/Makefile.am b/src/Makefile.am
index 65bc82a5ee38651052a47f788745647865d79117..941e69eeb256feb59cc8e68fd97204900c1a55b7 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -37,6 +37,7 @@ libnftnl_la_SOURCES = utils.c         \
                      expr/reject.c     \
                      expr/target.c     \
                      expr/masq.c       \
+                     expr/redir.c      \
                      expr/data_reg.h   \
                      libnftnl.map      \
                      expr_ops.h        \

diff --git a/src/expr/redir.c b/src/expr/redir.c
new file mode 100644 (file)
index 0000000..98e8850
--- /dev/null
+++ b/src/expr/redir.c
@@ -0,0 +1,303 @@
+/*
+ * (C) 2014 by Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
+ *
+ * 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 <arpa/inet.h>
+#include <errno.h>
+#include <inttypes.h>
+
+#include <linux/netfilter/nf_tables.h>
+
+#include "internal.h"
+#include <libmnl/libmnl.h>
+#include <libnftnl/expr.h>
+#include <libnftnl/rule.h>
+#include "expr_ops.h"
+
+struct nft_expr_redir {
+       enum nft_registers sreg_proto_min;
+       enum nft_registers sreg_proto_max;
+       uint32_t        flags;
+};
+
+static int
+nft_rule_expr_redir_set(struct nft_rule_expr *e, uint16_t type,
+                       const void *data, uint32_t data_len)
+{
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       switch (type) {
+       case NFT_EXPR_REDIR_REG_PROTO_MIN:
+               redir->sreg_proto_min = *((uint32_t *)data);
+               break;
+       case NFT_EXPR_REDIR_REG_PROTO_MAX:
+               redir->sreg_proto_max = *((uint32_t *)data);
+               break;
+       case NFT_EXPR_REDIR_FLAGS:
+               redir->flags = *((uint32_t *)data);
+               break;
+       default:
+               return -1;
+       }
+       return 0;
+}
+
+static const void *
+nft_rule_expr_redir_get(const struct nft_rule_expr *e, uint16_t type,
+                       uint32_t *data_len)
+{
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       switch (type) {
+       case NFT_EXPR_REDIR_REG_PROTO_MIN:
+               *data_len = sizeof(redir->sreg_proto_min);
+               return &redir->sreg_proto_min;
+       case NFT_EXPR_REDIR_REG_PROTO_MAX:
+               *data_len = sizeof(redir->sreg_proto_max);
+               return &redir->sreg_proto_max;
+       case NFT_EXPR_REDIR_FLAGS:
+               *data_len = sizeof(redir->flags);
+               return &redir->flags;
+       }
+       return NULL;
+}
+
+static int nft_rule_expr_redir_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_REDIR_MAX) < 0)
+               return MNL_CB_OK;
+
+       switch (type) {
+       case NFTA_REDIR_REG_PROTO_MIN:
+       case NFTA_REDIR_REG_PROTO_MAX:
+       case NFTA_REDIR_FLAGS:
+               if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)
+                       abi_breakage();
+               break;
+       }
+
+       tb[type] = attr;
+       return MNL_CB_OK;
+}
+
+static void
+nft_rule_expr_redir_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
+{
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       if (e->flags & (1 << NFT_EXPR_REDIR_REG_PROTO_MIN))
+               mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MIN,
+                                htobe32(redir->sreg_proto_min));
+       if (e->flags & (1 << NFT_EXPR_REDIR_REG_PROTO_MAX))
+               mnl_attr_put_u32(nlh, NFTA_REDIR_REG_PROTO_MAX,
+                                htobe32(redir->sreg_proto_max));
+       if (e->flags & (1 << NFT_EXPR_REDIR_FLAGS))
+               mnl_attr_put_u32(nlh, NFTA_REDIR_FLAGS, htobe32(redir->flags));
+}
+
+static int
+nft_rule_expr_redir_parse(struct nft_rule_expr *e, struct nlattr *attr)
+{
+       struct nft_expr_redir *redir = nft_expr_data(e);
+       struct nlattr *tb[NFTA_REDIR_MAX + 1] = {};
+
+       if (mnl_attr_parse_nested(attr, nft_rule_expr_redir_cb, tb) < 0)
+               return -1;
+
+       if (tb[NFTA_REDIR_REG_PROTO_MIN]) {
+               redir->sreg_proto_min =
+                       ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MIN]));
+               e->flags |= (1 << NFT_EXPR_REDIR_REG_PROTO_MIN);
+       }
+       if (tb[NFTA_REDIR_REG_PROTO_MAX]) {
+               redir->sreg_proto_max =
+                       ntohl(mnl_attr_get_u32(tb[NFTA_REDIR_REG_PROTO_MAX]));
+               e->flags |= (1 << NFT_EXPR_REDIR_REG_PROTO_MAX);
+       }
+       if (tb[NFTA_REDIR_FLAGS]) {
+               redir->flags = be32toh(mnl_attr_get_u32(tb[NFTA_REDIR_FLAGS]));
+               e->flags |= (1 << NFT_EXPR_REDIR_FLAGS);
+       }
+
+       return 0;
+}
+
+static int
+nft_rule_expr_redir_json_parse(struct nft_rule_expr *e, json_t *root,
+                              struct nft_parse_err *err)
+{
+#ifdef JSON_PARSING
+       uint32_t reg, flags;
+
+       if (nft_jansson_parse_reg(root, "sreg_proto_min", NFT_TYPE_U32,
+                                 &reg, err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_REG_PROTO_MIN, reg);
+
+       if (nft_jansson_parse_reg(root, "sreg_proto_max", NFT_TYPE_U32,
+                                 &reg, err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_REG_PROTO_MAX, reg);
+
+       if (nft_jansson_parse_val(root, "flags", NFT_TYPE_U32, &flags,
+                                 err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_FLAGS, flags);
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static int
+nft_rule_expr_redir_xml_parse(struct nft_rule_expr *e, mxml_node_t *tree,
+                             struct nft_parse_err *err)
+{
+#ifdef XML_PARSING
+       uint32_t reg, flags;
+
+       if (nft_mxml_reg_parse(tree, "sreg_proto_min", &reg,
+                              MXML_DESCEND, NFT_XML_OPT, err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_REG_PROTO_MIN, reg);
+
+       if (nft_mxml_reg_parse(tree, "sreg_proto_max", &reg,
+                              MXML_DESCEND, NFT_XML_OPT, err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_REG_PROTO_MAX, reg);
+
+       if (nft_mxml_num_parse(tree, "flags", MXML_DESCEND_FIRST, BASE_DEC,
+                              &flags, NFT_TYPE_U32, NFT_XML_OPT, err) == 0)
+               nft_rule_expr_set_u32(e, NFT_EXPR_REDIR_FLAGS, flags);
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static int nft_rule_expr_redir_snprintf_json(char *buf, size_t len,
+                                            struct nft_rule_expr *e)
+{
+       int ret, size = len, offset = 0;
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MIN)) {
+               ret = snprintf(buf + offset, len, "\"sreg_proto_min\":%u,",
+                              redir->sreg_proto_min);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MAX)) {
+               ret = snprintf(buf + offset, len, "\"sreg_proto_max\":%u,",
+                              redir->sreg_proto_max);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_FLAGS)) {
+               ret = snprintf(buf + offset, len, "\"flags\":%u",
+                              redir->flags);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       return offset;
+}
+
+static int nft_rule_expr_redir_snprintf_xml(char *buf, size_t len,
+                                           struct nft_rule_expr *e)
+{
+       int ret, size = len, offset = 0;
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MIN)) {
+               ret = snprintf(buf + offset, len,
+                              "<sreg_proto_min>%u<sreg_proto_min>",
+                              redir->sreg_proto_min);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MAX)) {
+               ret = snprintf(buf + offset, len,
+                              "<sreg_proto_max>%u</sreg_proto_max>",
+                              redir->sreg_proto_max);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_FLAGS)) {
+               ret = snprintf(buf + offset, len, "<flags>%u</flags>",
+                              redir->flags);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       return offset;
+}
+
+static int nft_rule_expr_redir_snprintf_default(char *buf, size_t len,
+                                               struct nft_rule_expr *e)
+{
+       int ret, size = len, offset = 0;
+       struct nft_expr_redir *redir = nft_expr_data(e);
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MIN)) {
+               ret = snprintf(buf + offset, len, "proto_min reg %u ",
+                              redir->sreg_proto_min);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_REG_PROTO_MAX)) {
+               ret = snprintf(buf + offset, len, "proto_max reg %u ",
+                              redir->sreg_proto_max);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       if (nft_rule_expr_is_set(e, NFT_EXPR_REDIR_FLAGS)) {
+               ret = snprintf(buf + offset , len, "flags 0x%x ",
+                              redir->flags);
+               SNPRINTF_BUFFER_SIZE(ret, size, len, offset);
+       }
+
+       return 0;
+}
+
+static int
+nft_rule_expr_redir_snprintf(char *buf, size_t len, uint32_t type,
+                            uint32_t flags, struct nft_rule_expr *e)
+{
+       switch (type) {
+       case NFT_OUTPUT_DEFAULT:
+               return nft_rule_expr_redir_snprintf_default(buf, len, e);
+       case NFT_OUTPUT_XML:
+               return nft_rule_expr_redir_snprintf_xml(buf, len, e);
+       case NFT_OUTPUT_JSON:
+               return nft_rule_expr_redir_snprintf_json(buf, len, e);
+       default:
+               break;
+       }
+       return -1;
+}
+
+struct expr_ops expr_ops_redir = {
+       .name           = "redir",
+       .alloc_len      = sizeof(struct nft_expr_redir),
+       .max_attr       = NFTA_REDIR_MAX,
+       .set            = nft_rule_expr_redir_set,
+       .get            = nft_rule_expr_redir_get,
+       .parse          = nft_rule_expr_redir_parse,
+       .build          = nft_rule_expr_redir_build,
+       .snprintf       = nft_rule_expr_redir_snprintf,
+       .xml_parse      = nft_rule_expr_redir_xml_parse,
+       .json_parse     = nft_rule_expr_redir_json_parse,
+};
+
+static void __init expr_redir_init(void)
+{
+       nft_expr_ops_register(&expr_ops_redir);
+}