[PATCH nft] optimize: do not assume log prefix

[Pablo Neira Ayuso <pablo@netfilter.org>]

... log prefix might not be present in log statements.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 src/optimize.c                                    | 15 ++++++++++++---
 .../testcases/optimizations/dumps/merge_vmaps.nft |  1 +
 tests/shell/testcases/optimizations/merge_vmaps   |  1 +
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/src/optimize.c b/src/optimize.c
index f8dd7f8d159f..7a268c452226 100644
--- a/src/optimize.c
+++ b/src/optimize.c
@@ -153,8 +153,16 @@ static bool __stmt_type_eq(const struct stmt *stmt_a, const struct stmt *stmt_b)
 		    stmt_a->log.qthreshold != stmt_b->log.qthreshold ||
 		    stmt_a->log.level != stmt_b->log.level ||
 		    stmt_a->log.logflags != stmt_b->log.logflags ||
-		    stmt_a->log.flags != stmt_b->log.flags ||
-		    stmt_a->log.prefix->etype != EXPR_VALUE ||
+		    stmt_a->log.flags != stmt_b->log.flags)
+			return false;
+
+		if (!!stmt_a->log.prefix ^ !!stmt_b->log.prefix)
+			return false;
+
+		if (!stmt_a->log.prefix)
+			return true;
+
+		if (stmt_a->log.prefix->etype != EXPR_VALUE ||
 		    stmt_b->log.prefix->etype != EXPR_VALUE ||
 		    mpz_cmp(stmt_a->log.prefix->value, stmt_b->log.prefix->value))
 			return false;
@@ -265,7 +273,8 @@ static int rule_collect_stmts(struct optimize_ctx *ctx, struct rule *rule)
 			break;
 		case STMT_LOG:
 			memcpy(&clone->log, &stmt->log, sizeof(clone->log));
-			clone->log.prefix = expr_get(stmt->log.prefix);
+			if (stmt->log.prefix)
+				clone->log.prefix = expr_get(stmt->log.prefix);
 			break;
 		default:
 			break;
diff --git a/tests/shell/testcases/optimizations/dumps/merge_vmaps.nft b/tests/shell/testcases/optimizations/dumps/merge_vmaps.nft
index c1c9743b9f8c..05b9e575c272 100644
--- a/tests/shell/testcases/optimizations/dumps/merge_vmaps.nft
+++ b/tests/shell/testcases/optimizations/dumps/merge_vmaps.nft
@@ -8,5 +8,6 @@ table ip x {
 	chain y {
 		tcp dport vmap { 80 : accept, 81 : accept, 443 : accept, 8000-8100 : accept, 24000-25000 : accept }
 		meta l4proto vmap { tcp : goto filter_in_tcp, udp : goto filter_in_udp }
+		log
 	}
 }
diff --git a/tests/shell/testcases/optimizations/merge_vmaps b/tests/shell/testcases/optimizations/merge_vmaps
index 7b7a2723be4b..0922a221bd6d 100755
--- a/tests/shell/testcases/optimizations/merge_vmaps
+++ b/tests/shell/testcases/optimizations/merge_vmaps
@@ -19,6 +19,7 @@ RULESET="table ip x {
 		}
 		meta l4proto tcp goto filter_in_tcp
 		meta l4proto udp goto filter_in_udp
+		log
 	}
 }"
 
-- 
2.30.2