65 lines
2.2 KiB
Diff
65 lines
2.2 KiB
Diff
|
From 64f34f34acedad6cce70f2dd91c82a814d4ffe34 Mon Sep 17 00:00:00 2001
|
||
|
|
From: Phil Sutter <psutter@redhat.com>
|
||
|
|
Date: Wed, 19 May 2021 18:03:43 +0200
|
||
|
|
Subject: [PATCH] src: Support odd-sized payload matches
|
||
|
|
|
||
|
|
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1934926
|
||
|
|
Upstream Status: nftables commit 8a927c56d83ed
|
||
|
|
|
||
|
|
commit 8a927c56d83ed0f78785011bd92a53edc25a0ca0
|
||
|
|
Author: Phil Sutter <phil@nwl.cc>
|
||
|
|
Date: Tue Oct 27 17:05:25 2020 +0100
|
||
|
|
|
||
|
|
src: Support odd-sized payload matches
|
||
|
|
|
||
|
|
When expanding a payload match, don't disregard oversized templates at
|
||
|
|
the right offset. A more flexible user may extract less bytes from the
|
||
|
|
packet if only parts of a field are interesting, e.g. only the prefix of
|
||
|
|
source/destination address. Support that by using the template, but fix
|
||
|
|
the length. Later when creating a relational expression for it, detect
|
||
|
|
the unusually small payload expression length and turn the RHS value
|
||
|
|
into a prefix expression.
|
||
|
|
|
||
|
|
Signed-off-by: Phil Sutter <phil@nwl.cc>
|
||
|
|
---
|
||
|
|
src/netlink_delinearize.c | 6 ++++++
|
||
|
|
src/payload.c | 5 +++++
|
||
|
|
2 files changed, 11 insertions(+)
|
||
|
|
|
||
|
|
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
|
||
|
|
index 88dbd5a..8bdee12 100644
|
||
|
|
--- a/src/netlink_delinearize.c
|
||
|
|
+++ b/src/netlink_delinearize.c
|
||
|
|
@@ -1577,6 +1577,12 @@ static void payload_match_expand(struct rule_pp_ctx *ctx,
|
||
|
|
tmp = constant_expr_splice(right, left->len);
|
||
|
|
expr_set_type(tmp, left->dtype, left->byteorder);
|
||
|
|
|
||
|
|
+ if (left->payload.tmpl && (left->len < left->payload.tmpl->len)) {
|
||
|
|
+ mpz_lshift_ui(tmp->value, left->payload.tmpl->len - left->len);
|
||
|
|
+ tmp->len = left->payload.tmpl->len;
|
||
|
|
+ tmp = prefix_expr_alloc(&tmp->location, tmp, left->len);
|
||
|
|
+ }
|
||
|
|
+
|
||
|
|
nexpr = relational_expr_alloc(&expr->location, expr->op,
|
||
|
|
left, tmp);
|
||
|
|
if (expr->op == OP_EQ)
|
||
|
|
diff --git a/src/payload.c b/src/payload.c
|
||
|
|
index 3576400..45280ef 100644
|
||
|
|
--- a/src/payload.c
|
||
|
|
+++ b/src/payload.c
|
||
|
|
@@ -746,6 +746,11 @@ void payload_expr_expand(struct list_head *list, struct expr *expr,
|
||
|
|
expr->payload.offset += tmpl->len;
|
||
|
|
if (expr->len == 0)
|
||
|
|
return;
|
||
|
|
+ } else if (expr->len > 0) {
|
||
|
|
+ new = payload_expr_alloc(&expr->location, desc, i);
|
||
|
|
+ new->len = expr->len;
|
||
|
|
+ list_add_tail(&new->list, list);
|
||
|
|
+ return;
|
||
|
|
} else
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
--
|
||
|
|
2.31.1
|
||
|
|
|