This patch introduces the use of nft input files variables in chain policy.
e.g.
define default_policy = "accept"
add table ip foo
add chain ip foo bar {type filter hook input priority filter; policy $default_policy}
table ip foo {
chain bar {
type filter hook input priority filter; policy accept;
}
}
Signed-off-by: Fernando Fernandez Mancera <ffmancera@xxxxxxxxxx>
---
include/rule.h | 2 +-
src/evaluate.c | 51 +++++++++++++++++++
src/json.c | 5 +-
src/mnl.c | 9 ++--
src/netlink.c | 8 ++-
src/parser_bison.y | 19 +++++--
src/parser_json.c | 17 +++++--
src/rule.c | 13 +++--
.../testcases/nft-f/0025policy_variable_0 | 17 +++++++
.../testcases/nft-f/0026policy_variable_0 | 17 +++++++
.../testcases/nft-f/0027policy_variable_1 | 18 +++++++
.../testcases/nft-f/0028policy_variable_1 | 18 +++++++
.../nft-f/dumps/0025policy_variable_0.nft | 5 ++
.../nft-f/dumps/0026policy_variable_0.nft | 5 ++
14 files changed, 186 insertions(+), 18 deletions(-)
create mode 100755 tests/shell/testcases/nft-f/0025policy_variable_0
create mode 100755 tests/shell/testcases/nft-f/0026policy_variable_0
create mode 100755 tests/shell/testcases/nft-f/0027policy_variable_1
create mode 100755 tests/shell/testcases/nft-f/0028policy_variable_1
create mode 100644 tests/shell/testcases/nft-f/dumps/0025policy_variable_0.nft
create mode 100644 tests/shell/testcases/nft-f/dumps/0026policy_variable_0.nft
diff --git a/include/rule.h b/include/rule.h
index c6e8716..b12165a 100644
--- a/include/rule.h
+++ b/include/rule.h
@@ -209,7 +209,7 @@ struct chain {
const char *hookstr;
unsigned int hooknum;
struct prio_spec priority;
- int policy;
+ struct expr *policy;
const char *type;
const char *dev;
struct scope scope;
diff --git a/src/evaluate.c b/src/evaluate.c
index d2faee8..4d8bfbf 100755
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -3415,6 +3415,52 @@ static uint32_t str2hooknum(uint32_t family, const char *hook)
return NF_INET_NUMHOOKS;
}
+static bool evaluate_policy(struct eval_ctx *ctx, struct expr **policy)
+{
+ char policy_str[NFT_NAME_MAXLEN];
+ struct location loc;
+ int policy_num;
+
+ ctx->ectx.len = NFT_NAME_MAXLEN * BITS_PER_BYTE;
+ if (expr_evaluate(ctx, policy) < 0)
+ return false;
+ if ((*policy)->etype != EXPR_VALUE) {
+ expr_error(ctx->msgs, *policy, "%s is not a valid "
+ "policy expression", expr_name(*policy));
+ return false;
+ }
+
+ if ((*policy)->dtype->type == TYPE_STRING) {
+ mpz_export_data(policy_str, (*policy)->value,
+ BYTEORDER_HOST_ENDIAN,
+ NFT_NAME_MAXLEN);
+ loc = (*policy)->location;
+ if (!strcmp(policy_str, "accept")) {
+ expr_free(*policy);
+ policy_num = NF_ACCEPT;
+ *policy = constant_expr_alloc(&loc,
+ &integer_type,
+ BYTEORDER_HOST_ENDIAN,
+ sizeof(int) * BITS_PER_BYTE,
+ &policy_num);
+ } else if (!strcmp(policy_str, "drop")) {
+ expr_free(*policy);
+ policy_num = NF_DROP;
+ *policy = constant_expr_alloc(&(*policy)->location,
+ &integer_type,
+ BYTEORDER_HOST_ENDIAN,
+ sizeof(int) * BITS_PER_BYTE,
+ &policy_num);
+ } else {
+ expr_error(ctx->msgs, *policy, "%s is not a valid policy"
+ " value", policy_str);
+ return false;
+ }
+ }
+
+ return true;
+}
+
static int chain_evaluate(struct eval_ctx *ctx, struct chain *chain)
{
struct table *table;
@@ -3448,6 +3494,11 @@ static int chain_evaluate(struct eval_ctx *ctx, struct chain *chain)
return __stmt_binary_error(ctx, &chain->priority.loc, NULL,
"invalid priority expression %s in this context.",
expr_name(chain->priority.expr));
+ if (chain->policy) {
+ if (!evaluate_policy(ctx, &chain->policy))
+ return chain_error(ctx, chain, "invalid policy expression %s",
+ expr_name(chain->policy));
+ }
}
list_for_each_entry(rule, &chain->rules, list) {
diff --git a/src/json.c b/src/json.c
index 33e0ec1..ff2e06e 100644
--- a/src/json.c
+++ b/src/json.c
@@ -223,6 +223,7 @@ static json_t *rule_print_json(struct output_ctx *octx,
static json_t *chain_print_json(const struct chain *chain)
{
json_t *root, *tmp;
+ int policy;
root = json_pack("{s:s, s:s, s:s, s:I}",
"family", family2str(chain->handle.family),
@@ -231,12 +232,14 @@ static json_t *chain_print_json(const struct chain *chain)
"handle", chain->handle.handle.id);
if (chain->flags & CHAIN_F_BASECHAIN) {
+ mpz_export_data(&policy, chain->policy->value,
+ BYTEORDER_HOST_ENDIAN, sizeof(int));
tmp = json_pack("{s:s, s:s, s:i, s:s}",
"type", chain->type,
"hook", hooknum2str(chain->handle.family,
chain->hooknum),
"prio", chain->priority.num,
- "policy", chain_policy2str(chain->policy));
+ "policy", chain_policy2str(policy));
if (chain->dev)
json_object_set_new(tmp, "dev", json_string(chain->dev));
json_object_update(root, tmp);
diff --git a/src/mnl.c b/src/mnl.c
index eab8d54..ab71a00 100644
--- a/src/mnl.c
+++ b/src/mnl.c
@@ -518,6 +518,7 @@ int mnl_nft_chain_add(struct netlink_ctx *ctx, const struct cmd *cmd,
{
struct nftnl_chain *nlc;
struct nlmsghdr *nlh;
+ int policy;
nlc = nftnl_chain_alloc();
if (nlc == NULL)
@@ -536,9 +537,11 @@ int mnl_nft_chain_add(struct netlink_ctx *ctx, const struct cmd *cmd,
nftnl_chain_set_str(nlc, NFTNL_CHAIN_TYPE,
cmd->chain->type);
}
- if (cmd->chain->policy != -1)
- nftnl_chain_set_u32(nlc, NFTNL_CHAIN_POLICY,
- cmd->chain->policy);
+ if (cmd->chain->policy) {
+ mpz_export_data(&policy, cmd->chain->policy->value,
+ BYTEORDER_HOST_ENDIAN, sizeof(int));
+ nftnl_chain_set_u32(nlc, NFTNL_CHAIN_POLICY, policy);
+ }
if (cmd->chain->dev != NULL)
nftnl_chain_set_str(nlc, NFTNL_CHAIN_DEV,
cmd->chain->dev);
diff --git a/src/netlink.c b/src/netlink.c
index 14b0df4..d2be63c 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -369,6 +369,7 @@ struct chain *netlink_delinearize_chain(struct netlink_ctx *ctx,
const struct nftnl_chain *nlc)
{
struct chain *chain;
+ int policy;
chain = chain_alloc(nftnl_chain_get_str(nlc, NFTNL_CHAIN_NAME));
chain->handle.family =
@@ -390,7 +391,12 @@ struct chain *netlink_delinearize_chain(struct netlink_ctx *ctx,
nftnl_chain_get_s32(nlc, NFTNL_CHAIN_PRIO);
chain->type =
xstrdup(nftnl_chain_get_str(nlc, NFTNL_CHAIN_TYPE));
- chain->policy =
+ policy = nftnl_chain_get_u32(nlc, NFTNL_CHAIN_POLICY);
+ chain->policy = constant_expr_alloc(&netlink_location,
+ &string_type,
+ BYTEORDER_HOST_ENDIAN,
+ sizeof(int) * BITS_PER_BYTE,
+ &policy);
nftnl_chain_get_u32(nlc, NFTNL_CHAIN_POLICY);
if (nftnl_chain_is_set(nlc, NFTNL_CHAIN_DEV)) {
chain->dev =
diff --git a/src/parser_bison.y b/src/parser_bison.y
index 8ff2235..9edd870 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -636,8 +636,8 @@ int nft_lex(void *, void *, void *);
%type <stmt> meter_stmt meter_stmt_alloc flow_stmt_legacy_alloc
%destructor { stmt_free($$); } meter_stmt meter_stmt_alloc flow_stmt_legacy_alloc
-%type <expr> symbol_expr verdict_expr integer_expr variable_expr chain_expr prio_expr
-%destructor { expr_free($$); } symbol_expr verdict_expr integer_expr variable_expr chain_expr prio_expr
+%type <expr> symbol_expr verdict_expr integer_expr variable_expr chain_expr prio_expr policy_expr
+%destructor { expr_free($$); } symbol_expr verdict_expr integer_expr variable_expr chain_expr prio_expr policy_expr
%type <expr> primary_expr shift_expr and_expr
%destructor { expr_free($$); } primary_expr shift_expr and_expr
%type <expr> exclusive_or_expr inclusive_or_expr
@@ -2020,17 +2020,28 @@ dev_spec : DEVICE string { $$ = $2; }
| /* empty */ { $$ = NULL; }
;
-policy_spec : POLICY chain_policy
+policy_spec : POLICY policy_expr
{
- if ($<chain>0->policy != -1) {
+ if ($<chain>0->policy) {
erec_queue(error(&@$, "you cannot set chain policy twice"),
state->msgs);
+ expr_free($2);
YYERROR;
}
$<chain>0->policy = $2;
}
;
+policy_expr : variable_expr
+ | chain_policy
+ {
+ $$ = constant_expr_alloc(&@$, &integer_type,
+ BYTEORDER_HOST_ENDIAN,
+ sizeof(int) *
+ BITS_PER_BYTE, &$1);
+ }
+ ;
+
chain_policy : ACCEPT { $$ = NF_ACCEPT; }
| DROP { $$ = NF_DROP; }
;
diff --git a/src/parser_json.c b/src/parser_json.c
index 76c0a5c..a227b17 100644
--- a/src/parser_json.c
+++ b/src/parser_json.c
@@ -2530,13 +2530,20 @@ static struct cmd *json_parse_cmd_add_table(struct json_ctx *ctx, json_t *root,
return cmd_alloc(op, obj, &h, int_loc, NULL);
}
-static int parse_policy(const char *policy)
+static struct expr *parse_policy(const char *policy)
{
+ int policy_num;
+
if (!strcmp(policy, "accept"))
- return NF_ACCEPT;
- if (!strcmp(policy, "drop"))
- return NF_DROP;
- return -1;
+ policy_num = NF_ACCEPT;
+ else if (!strcmp(policy, "drop"))
+ policy_num = NF_DROP;
+ else
+ return NULL;
+
+ return constant_expr_alloc(int_loc, &integer_type,
+ BYTEORDER_HOST_ENDIAN, sizeof(int)
+ * BITS_PER_BYTE, &policy_num);
}
static struct cmd *json_parse_cmd_add_chain(struct json_ctx *ctx, json_t *root,
diff --git a/src/rule.c b/src/rule.c
index 23011d9..afa46e9 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -800,7 +800,7 @@ struct chain *chain_alloc(const char *name)
if (name != NULL)
chain->handle.chain.name = xstrdup(name);
- chain->policy = -1;
+ chain->policy = NULL;
return chain;
}
@@ -824,6 +824,7 @@ void chain_free(struct chain *chain)
if (chain->dev != NULL)
xfree(chain->dev);
expr_free(chain->priority.expr);
+ expr_free(chain->policy);
xfree(chain);
}
@@ -1099,12 +1100,15 @@ static void chain_print_declaration(const struct chain *chain,
struct output_ctx *octx)
{
char priobuf[STD_PRIO_BUFSIZE];
+ int policy;
nft_print(octx, "\tchain %s {", chain->handle.chain.name);
if (nft_output_handle(octx))
nft_print(octx, " # handle %" PRIu64, chain->handle.handle.id);
nft_print(octx, "\n");
if (chain->flags & CHAIN_F_BASECHAIN) {
+ mpz_export_data(&policy, chain->policy->value,
+ BYTEORDER_HOST_ENDIAN, sizeof(int));
nft_print(octx, "\t\ttype %s hook %s", chain->type,
hooknum2str(chain->handle.family, chain->hooknum));
if (chain->dev != NULL)
@@ -1113,7 +1117,7 @@ static void chain_print_declaration(const struct chain *chain,
prio2str(octx, priobuf, sizeof(priobuf),
chain->handle.family, chain->hooknum,
chain->priority.num),
- chain_policy2str(chain->policy));
+ chain_policy2str(policy));
}
}
@@ -1134,17 +1138,20 @@ static void chain_print(const struct chain *chain, struct output_ctx *octx)
void chain_print_plain(const struct chain *chain, struct output_ctx *octx)
{
char priobuf[STD_PRIO_BUFSIZE];
+ int policy;
nft_print(octx, "chain %s %s %s", family2str(chain->handle.family),
chain->handle.table.name, chain->handle.chain.name);
if (chain->flags & CHAIN_F_BASECHAIN) {
+ mpz_export_data(&policy, chain->policy->value,
+ BYTEORDER_HOST_ENDIAN, 4);
nft_print(octx, " { type %s hook %s priority %s; policy %s; }",
chain->type, chain->hookstr,
prio2str(octx, priobuf, sizeof(priobuf),
chain->handle.family, chain->hooknum,
chain->priority.num),
- chain_policy2str(chain->policy));
+ chain_policy2str(policy));
}
if (nft_output_handle(octx))
nft_print(octx, " # handle %" PRIu64, chain->handle.handle.id);
diff --git a/tests/shell/testcases/nft-f/0025policy_variable_0 b/tests/shell/testcases/nft-f/0025policy_variable_0
new file mode 100755
index 0000000..b88e968
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0025policy_variable_0
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Tests use of variables in chain policy
+
+set -e
+
+RULESET="
+define default_policy = \"accept\"
+
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter
+ policy \$default_policy
+ }
+}"
+
+$NFT -f - <<< "$RULESET"
diff --git a/tests/shell/testcases/nft-f/0026policy_variable_0 b/tests/shell/testcases/nft-f/0026policy_variable_0
new file mode 100755
index 0000000..d4d98ed
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0026policy_variable_0
@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Tests use of variables in chain policy
+
+set -e
+
+RULESET="
+define default_policy = \"drop\"
+
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter
+ policy \$default_policy
+ }
+}"
+
+$NFT -f - <<< "$RULESET"
diff --git a/tests/shell/testcases/nft-f/0027policy_variable_1 b/tests/shell/testcases/nft-f/0027policy_variable_1
new file mode 100755
index 0000000..ae35516
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0027policy_variable_1
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Tests use of variables in chain policy
+
+set -e
+
+RULESET="
+define default_policy = { 127.0.0.1 }
+
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter
+ policy \$default_policy
+ }
+}"
+
+$NFT -f - <<< "$RULESET" && exit 1
+exit 0
diff --git a/tests/shell/testcases/nft-f/0028policy_variable_1 b/tests/shell/testcases/nft-f/0028policy_variable_1
new file mode 100755
index 0000000..027eb01
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0028policy_variable_1
@@ -0,0 +1,18 @@
+#!/bin/bash
+
+# Tests use of variables in priority specification
+
+set -e
+
+RULESET="
+define default_policy = *
+
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter
+ policy \$default_policy
+ }
+}"
+
+$NFT -f - <<< "$RULESET" && exit 1
+exit 0
diff --git a/tests/shell/testcases/nft-f/dumps/0025policy_variable_0.nft b/tests/shell/testcases/nft-f/dumps/0025policy_variable_0.nft
new file mode 100644
index 0000000..f409309
--- /dev/null
+++ b/tests/shell/testcases/nft-f/dumps/0025policy_variable_0.nft
@@ -0,0 +1,5 @@
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter; policy accept;
+ }
+}
diff --git a/tests/shell/testcases/nft-f/dumps/0026policy_variable_0.nft b/tests/shell/testcases/nft-f/dumps/0026policy_variable_0.nft
new file mode 100644
index 0000000..d729e1e
--- /dev/null
+++ b/tests/shell/testcases/nft-f/dumps/0026policy_variable_0.nft
@@ -0,0 +1,5 @@
+table inet global {
+ chain prerouting {
+ type filter hook prerouting priority filter; policy drop;
+ }
+}
--
2.20.1
