[PATCH 2/2 nft v2] jump: Allow goto and jump to a variable using nft input files

[Fernando Fernandez Mancera]

This patch introduces the use of nft input files variables in 'jump' and 'goto'
statements, e.g.

define dest = ber

add table ip foo
add chain ip foo bar {type filter hook input priority 0;}
add chain ip foo ber
add rule ip foo ber counter
add rule ip foo bar jump $dest

table ip foo {
        chain bar {
                type filter hook input priority filter; policy accept;
                jump ber
        }

        chain ber {
                counter packets 71 bytes 6664
        }
}

Signed-off-by: Fernando Fernandez Mancera <ffmanc...@riseup.net>
---
 src/datatype.c                                | 11 +++++++++++
 src/parser_bison.y                            |  3 ++-
 .../shell/testcases/nft-f/0018jump_variable_0 | 19 +++++++++++++++++++
 .../nft-f/dumps/0018jump_variable_0.nft       |  8 ++++++++
 4 files changed, 40 insertions(+), 1 deletion(-)
 create mode 100755 tests/shell/testcases/nft-f/0018jump_variable_0
 create mode 100644 tests/shell/testcases/nft-f/dumps/0018jump_variable_0.nft

diff --git a/src/datatype.c b/src/datatype.c
index 10f185b..1d5ed6f 100644
--- a/src/datatype.c
+++ b/src/datatype.c
@@ -309,11 +309,22 @@ static void verdict_type_print(const struct expr *expr, 
struct output_ctx *octx)
        }
 }
 
+static struct error_record *verdict_type_parse(const struct expr *sym,
+                                              struct expr **res)
+{
+       *res = constant_expr_alloc(&sym->location, &string_type,
+                                  BYTEORDER_HOST_ENDIAN,
+                                  (strlen(sym->identifier) + 1) * 
BITS_PER_BYTE,
+                                  sym->identifier);
+       return NULL;
+}
+
 const struct datatype verdict_type = {
        .type           = TYPE_VERDICT,
        .name           = "verdict",
        .desc           = "netfilter verdict",
        .print          = verdict_type_print,
+       .parse          = verdict_type_parse,
 };
 
 static const struct symbol_table nfproto_tbl = {
diff --git a/src/parser_bison.y b/src/parser_bison.y
index b1e29a8..0fea3c6 100644
--- a/src/parser_bison.y
+++ b/src/parser_bison.y
@@ -3841,7 +3841,8 @@ verdict_expr              :       ACCEPT
                        }
                        ;
 
-chain_expr             :       identifier
+chain_expr             :       variable_expr
+                       |       identifier
                        {
                                $$ = constant_expr_alloc(&@$, &string_type,
                                                         BYTEORDER_HOST_ENDIAN,
diff --git a/tests/shell/testcases/nft-f/0018jump_variable_0 
b/tests/shell/testcases/nft-f/0018jump_variable_0
new file mode 100755
index 0000000..003a1bd
--- /dev/null
+++ b/tests/shell/testcases/nft-f/0018jump_variable_0
@@ -0,0 +1,19 @@
+#!/bin/bash
+
+# Tests use of variables in jump statements
+
+set -e
+
+RULESET="
+define dest = ber
+
+table ip foo {
+       chain bar {
+               jump \$dest
+       }
+
+       chain ber {
+       }
+}"
+
+$NFT -f - <<< "$RULESET"
diff --git a/tests/shell/testcases/nft-f/dumps/0018jump_variable_0.nft 
b/tests/shell/testcases/nft-f/dumps/0018jump_variable_0.nft
new file mode 100644
index 0000000..0ddaf07
--- /dev/null
+++ b/tests/shell/testcases/nft-f/dumps/0018jump_variable_0.nft
@@ -0,0 +1,8 @@
+table ip foo {
+       chain bar {
+               jump ber
+       }
+
+       chain ber {
+       }
+}
-- 
2.20.1