expr: add reject

This patch adds support for the reject expression.

Tested-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/libnftables/expr.h b/include/libnftables/expr.h
index 232a810a51a55f4154803fc5455b66f34f5f5c33..64c407ca29f34b3ab5536abfc085b0e6488bb2b2 100644 (file)
--- a/include/libnftables/expr.h
+++ b/include/libnftables/expr.h
@@ -137,6 +137,11 @@ enum {
        NFT_EXPR_LIMIT_UNIT,
 };
 
+enum {
+       NFT_EXPR_REJECT_TYPE    = NFT_RULE_EXPR_ATTR_BASE,
+       NFT_EXPR_REJECT_CODE,
+};
+
 #ifdef __cplusplus
 } /* extern "C" */
 #endif

diff --git a/src/Makefile.am b/src/Makefile.am
index 474dbf002df2e13afd83b0b13244f1bb248c72e3..5f64db20279ed0bad17ba60823b5f13cf4bd252a 100644 (file)
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -30,6 +30,7 @@ libnftables_la_SOURCES = utils.c              \
                         expr/meta.c            \
                         expr/nat.c             \
                         expr/payload.c         \
+                        expr/reject.c          \
                         expr/target.c          \
                         libnftables.map        \
                         internal.h

diff --git a/src/expr/reject.c b/src/expr/reject.c
new file mode 100644 (file)
index 0000000..ca008ef
--- /dev/null
+++ b/src/expr/reject.c
@@ -0,0 +1,213 @@
+/*
+ * (C) 2013 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.
+ *
+ * This code has been sponsored by Sophos Astaro <http://www.sophos.com>
+ */
+
+#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 <libnftables/expr.h>
+#include <libnftables/rule.h>
+#include "expr_ops.h"
+
+struct nft_expr_reject {
+       uint32_t                type;
+       uint8_t                 icmp_code;
+};
+
+static int nft_rule_expr_reject_set(struct nft_rule_expr *e, uint16_t type,
+                                   const void *data, uint32_t data_len)
+{
+       struct nft_expr_reject *reject = nft_expr_data(e);
+
+       switch(type) {
+       case NFT_EXPR_REJECT_TYPE:
+               reject->type = *((uint32_t *)data);
+               break;
+       case NFT_EXPR_REJECT_CODE:
+               reject->icmp_code = *((uint8_t *)data);
+               break;
+       default:
+               return -1;
+       }
+       return 0;
+}
+
+static const void *
+nft_rule_expr_reject_get(const struct nft_rule_expr *e, uint16_t type,
+                        uint32_t *data_len)
+{
+       struct nft_expr_reject *reject = nft_expr_data(e);
+
+       switch(type) {
+       case NFT_EXPR_REJECT_TYPE:
+               *data_len = sizeof(reject->type);
+               return &reject->type;
+       case NFT_EXPR_REJECT_CODE:
+               *data_len = sizeof(reject->icmp_code);
+               return &reject->icmp_code;
+       }
+       return NULL;
+}
+
+static int nft_rule_expr_reject_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_REJECT_MAX) < 0)
+               return MNL_CB_OK;
+
+       switch(type) {
+       case NFTA_REJECT_TYPE:
+               if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0) {
+                       perror("mnl_attr_validate");
+                       return MNL_CB_ERROR;
+               }
+               break;
+       case NFTA_REJECT_ICMP_CODE:
+               if (mnl_attr_validate(attr, MNL_TYPE_U8) < 0) {
+                       perror("mnl_attr_validate");
+                       return MNL_CB_ERROR;
+               }
+               break;
+       }
+
+       tb[type] = attr;
+       return MNL_CB_OK;
+}
+
+static void
+nft_rule_expr_reject_build(struct nlmsghdr *nlh, struct nft_rule_expr *e)
+{
+       struct nft_expr_reject *reject = nft_expr_data(e);
+
+       if (e->flags & (1 << NFT_EXPR_REJECT_TYPE))
+               mnl_attr_put_u32(nlh, NFTA_REJECT_TYPE, htonl(reject->type));
+       if (e->flags & (1 << NFT_EXPR_REJECT_CODE))
+               mnl_attr_put_u8(nlh, NFTA_REJECT_ICMP_CODE, reject->icmp_code);
+}
+
+static int
+nft_rule_expr_reject_parse(struct nft_rule_expr *e, struct nlattr *attr)
+{
+       struct nft_expr_reject *reject = nft_expr_data(e);
+       struct nlattr *tb[NFTA_REJECT_MAX+1] = {};
+
+       if (mnl_attr_parse_nested(attr, nft_rule_expr_reject_cb, tb) < 0)
+               return -1;
+
+       if (tb[NFTA_REJECT_TYPE]) {
+               reject->type = ntohl(mnl_attr_get_u32(tb[NFTA_REJECT_TYPE]));
+               e->flags |= (1 << NFT_EXPR_REJECT_TYPE);
+       }
+       if (tb[NFTA_REJECT_ICMP_CODE]) {
+               reject->icmp_code = mnl_attr_get_u8(tb[NFTA_REJECT_ICMP_CODE]);
+               e->flags |= (1 << NFT_EXPR_REJECT_CODE);
+       }
+
+       return 0;
+}
+
+static int
+nft_rule_expr_reject_json_parse(struct nft_rule_expr *e, json_t *root)
+{
+#ifdef JSON_PARSING
+       uint32_t type;
+       uint16_t code;
+
+       if (nft_jansson_parse_val(root, "type", NFT_TYPE_U32, &type) < 0)
+               return -1;
+
+       nft_rule_expr_set_u32(e, NFT_EXPR_REJECT_TYPE, type);
+
+       if (nft_jansson_parse_val(root, "code", NFT_TYPE_U8, &code) < 0)
+               return -1;
+
+       nft_rule_expr_set_u8(e, NFT_EXPR_REJECT_CODE, code);
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static int
+nft_rule_expr_reject_xml_parse(struct nft_rule_expr *e, mxml_node_t *tree)
+{
+#ifdef XML_PARSING
+       struct nft_expr_reject *reject = nft_expr_data(e);
+
+       if (nft_mxml_num_parse(tree, "type", MXML_DESCEND_FIRST, BASE_DEC,
+                              &reject->type, NFT_TYPE_U32, NFT_XML_MAND) != 0)
+               return -1;
+
+       e->flags |= (1 << NFT_EXPR_REJECT_TYPE);
+
+       if (nft_mxml_num_parse(tree, "code", MXML_DESCEND_FIRST, BASE_DEC,
+                              &reject->icmp_code, NFT_TYPE_U8, NFT_XML_MAND) != 0)
+               return -1;
+
+       e->flags |= (1 << NFT_EXPR_REJECT_CODE);
+
+       return 0;
+#else
+       errno = EOPNOTSUPP;
+       return -1;
+#endif
+}
+
+static int
+nft_rule_expr_reject_snprintf(char *buf, size_t len, uint32_t type,
+                             uint32_t flags, struct nft_rule_expr *e)
+{
+       struct nft_expr_reject *reject = nft_expr_data(e);
+
+       switch(type) {
+       case NFT_RULE_O_DEFAULT:
+               return snprintf(buf, len, "type %u code %u  ",
+                               reject->type, reject->icmp_code);
+       case NFT_RULE_O_XML:
+               return snprintf(buf, len, "<type>%u</type>"
+                                         "<code>%u</code>",
+                               reject->type, reject->icmp_code);
+       case NFT_RULE_O_JSON:
+               return snprintf(buf, len, "\"type\":%u,"
+                                         "\"code\":%u,",
+                               reject->type, reject->icmp_code);
+       default:
+               break;
+       }
+       return -1;
+}
+
+struct expr_ops expr_ops_reject = {
+       .name           = "reject",
+       .alloc_len      = sizeof(struct nft_expr_reject),
+       .max_attr       = NFTA_REJECT_MAX,
+       .set            = nft_rule_expr_reject_set,
+       .get            = nft_rule_expr_reject_get,
+       .parse          = nft_rule_expr_reject_parse,
+       .build          = nft_rule_expr_reject_build,
+       .snprintf       = nft_rule_expr_reject_snprintf,
+       .xml_parse      = nft_rule_expr_reject_xml_parse,
+       .json_parse     = nft_rule_expr_reject_json_parse,
+};
+
+static void __init expr_reject_init(void)
+{
+       nft_expr_ops_register(&expr_ops_reject);
+}