When called with --noflush, xtables-restore would trip over chain lines:
Parser uses strtok() to separate chain name, policy and counters which
inserts nul-chars into the source string. Therefore strlen() can't be
used anymore to find end of line. Fix this by caching line length before
calling xtables_restore_parse_line().
Fixes: 09cb517949e69 ("xtables-restore: Improve performance of --noflush operation")
Signed-off-by: Phil Sutter <phil@xxxxxx>
---
.../testcases/ipt-restore/0010-noflush-new-chain_0 | 10 ++++++++++
iptables/xtables-restore.c | 4 +++-
2 files changed, 13 insertions(+), 1 deletion(-)
create mode 100755 iptables/tests/shell/testcases/ipt-restore/0010-noflush-new-chain_0
diff --git a/iptables/tests/shell/testcases/ipt-restore/0010-noflush-new-chain_0 b/iptables/tests/shell/testcases/ipt-restore/0010-noflush-new-chain_0
new file mode 100755
index 0000000000000..739e684a21183
--- /dev/null
+++ b/iptables/tests/shell/testcases/ipt-restore/0010-noflush-new-chain_0
@@ -0,0 +1,10 @@
+#!/bin/sh -e
+
+# assert input feed from buffer doesn't trip over
+# added nul-chars from parsing chain line.
+
+$XT_MULTI iptables-restore --noflush <<EOF
+*filter
+:foobar - [0:0]
+-A foobar -j ACCEPT
+COMMIT
diff --git a/iptables/xtables-restore.c b/iptables/xtables-restore.c
index 2f0fe7d439d94..dd907e0b8ddd5 100644
--- a/iptables/xtables-restore.c
+++ b/iptables/xtables-restore.c
@@ -327,10 +327,12 @@ void xtables_restore_parse(struct nft_handle *h,
line = 0;
ptr = preload_buffer;
while (*ptr) {
+ size_t len = strlen(ptr);
+
h->error.lineno = ++line;
DEBUGP("%s: buffered line %d: '%s'\n", __func__, line, ptr);
xtables_restore_parse_line(h, p, &state, ptr);
- ptr += strlen(ptr) + 1;
+ ptr += len + 1;
}
if (*buffer) {
h->error.lineno = ++line;
--
2.24.0
