Now it is possible to store multiple variable length user data into rule.
Modify the parser in order to fill the nftnl_udata with the comment, and
the print function for extract these commentary and print it to user.
Signed-off-by: Carlos Falgueras García <carlosfg@xxxxxxxxxx>
---
include/rule.h | 11 +++++++++--
src/netlink_delinearize.c | 7 +++++--
src/netlink_linearize.c | 6 ++++--
src/parser_bison.y | 14 +++++++++++++-
src/rule.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
5 files changed, 73 insertions(+), 10 deletions(-)
diff --git a/include/rule.h b/include/rule.h
index c848f0f..c500e88 100644
--- a/include/rule.h
+++ b/include/rule.h
@@ -4,6 +4,7 @@
#include <stdint.h>
#include <nftables.h>
#include <list.h>
+#include <libnftnl/udata.h>
/**
* struct handle - handle for tables, chains, rules and sets
@@ -155,7 +156,7 @@ extern void chain_print_plain(const struct chain *chain);
* @location: location the rule was defined at
* @stmt: list of statements
* @num_stmts: number of statements in stmts list
- * @comment: comment
+ * @udata: user data
*/
struct rule {
struct list_head list;
@@ -163,7 +164,7 @@ struct rule {
struct location location;
struct list_head stmts;
unsigned int num_stmts;
- const char *comment;
+ struct nftnl_udata_buf *udata;
};
extern struct rule *rule_alloc(const struct location *loc,
@@ -396,4 +397,10 @@ extern int do_command(struct netlink_ctx *ctx, struct cmd *cmd);
extern int cache_update(enum cmd_ops cmd, struct list_head *msgs);
extern void cache_release(void);
+enum udata_type {
+ UDATA_TYPE_COMMENT,
+ __UDATA_TYPE_MAX,
+};
+#define UDATA_TYPE_MAX (__UDATA_TYPE_MAX - 1)
+
#endif /* NFTABLES_RULE_H */
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index d431588..e655e00 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -25,6 +25,7 @@
#include <utils.h>
#include <erec.h>
#include <sys/socket.h>
+#include <libnftnl/udata.h>
struct netlink_parse_ctx {
struct list_head *msgs;
@@ -1773,8 +1774,10 @@ struct rule *netlink_delinearize_rule(struct netlink_ctx *ctx,
uint32_t len;
data = nftnl_rule_get_data(nlr, NFTNL_RULE_USERDATA, &len);
- pctx->rule->comment = xmalloc(len);
- memcpy((char *)pctx->rule->comment, data, len);
+ pctx->rule->udata = nftnl_udata_alloc(len);
+ if (!pctx->rule->udata)
+ memory_allocation_error();
+ nftnl_udata_copy_data(pctx->rule->udata, data, len);
}
nftnl_expr_foreach((struct nftnl_rule *)nlr, netlink_parse_expr, pctx);
diff --git a/src/netlink_linearize.c b/src/netlink_linearize.c
index bb51de7..5ac438e 100644
--- a/src/netlink_linearize.c
+++ b/src/netlink_linearize.c
@@ -21,6 +21,7 @@
#include <netinet/in.h>
#include <linux/netfilter.h>
+#include <libnftnl/udata.h>
struct netlink_linearize_ctx {
@@ -1171,9 +1172,10 @@ void netlink_linearize_rule(struct netlink_ctx *ctx, struct nftnl_rule *nlr,
list_for_each_entry(stmt, &rule->stmts, list)
netlink_gen_stmt(&lctx, stmt);
- if (rule->comment)
+ if (rule->udata)
nftnl_rule_set_data(nlr, NFTNL_RULE_USERDATA,
- rule->comment, strlen(rule->comment) + 1);
+ nftnl_udata_data(rule->udata),
+ nftnl_udata_len(rule->udata));
netlink_dump_rule(nlr);
}
diff --git a/src/parser_bison.y b/src/parser_bison.y
index 90978ab..9f8c005 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -24,6 +24,7 @@
#include <netinet/icmp6.h>
#include <libnftnl/common.h>
#include <libnftnl/set.h>
+#include <libnftnl/udata.h>
#include <rule.h>
#include <statement.h>
@@ -1303,7 +1304,18 @@ rule : stmt_list comment_spec
struct stmt *i;
$$ = rule_alloc(&@$, NULL);
- $$->comment = $2;
+
+ if ($2) {
+ if (!($$->udata = nftnl_udata_alloc(NFT_USERDATA_MAXLEN)))
+ memory_allocation_error();
+
+ if (!nftnl_udata_put_strz($$->udata, UDATA_TYPE_COMMENT, $2)) {
+ erec_queue(error(&@2, "Comment too long: \"%s\"", $2),
+ state->msgs);
+ YYERROR;
+ }
+ }
+
list_for_each_entry(i, $1, list)
$$->num_stmts++;
list_splice_tail($1, &$$->stmts);
diff --git a/src/rule.c b/src/rule.c
index 0b78549..112ae85 100644
--- a/src/rule.c
+++ b/src/rule.c
@@ -23,6 +23,7 @@
#include <libnftnl/common.h>
#include <libnftnl/ruleset.h>
+#include <libnftnl/udata.h>
#include <netinet/ip.h>
#include <linux/netfilter.h>
#include <linux/netfilter_arp.h>
@@ -375,21 +376,59 @@ void rule_free(struct rule *rule)
{
stmt_list_free(&rule->stmts);
handle_free(&rule->handle);
- xfree(rule->comment);
+ nftnl_udata_free(rule->udata);
xfree(rule);
}
+static int rule_parse_udata_cb(const struct nftnl_udata *attr, void *data)
+{
+ unsigned char *value = nftnl_udata_attr_value(attr);
+ uint8_t type = nftnl_udata_attr_type(attr);
+ uint8_t len = nftnl_udata_attr_len(attr);
+ const struct nftnl_udata **tb = data;
+
+ switch (type) {
+ case UDATA_TYPE_COMMENT:
+ if (value[len - 1] != '\0')
+ return -1;
+ break;
+ default:
+ break;
+ };
+
+ tb[type] = attr;
+ return 1;
+}
+
+static void rule_print_udata(const struct nftnl_udata *tb[], uint8_t type)
+{
+ if (!tb[type])
+ return;
+
+ switch (type) {
+ case UDATA_TYPE_COMMENT:
+ printf("comment \"%s\" ",
+ (char *)nftnl_udata_attr_value(tb[type]));
+ break;
+ default:
+ break;
+ }
+}
+
void rule_print(const struct rule *rule)
{
const struct stmt *stmt;
+ const struct nftnl_udata *tb[UDATA_TYPE_MAX + 1] = {};
list_for_each_entry(stmt, &rule->stmts, list) {
stmt->ops->print(stmt);
printf(" ");
}
- if (rule->comment)
- printf("comment \"%s\" ", rule->comment);
+ if (rule->udata) {
+ if (nftnl_udata_parse(rule->udata, rule_parse_udata_cb, tb) > 0)
+ rule_print_udata(tb, UDATA_TYPE_COMMENT);
+ }
if (handle_output > 0)
printf("# handle %" PRIu64, rule->handle.handle);
--
2.7.2
--
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