From: Jeremy Sowden <jeremy@azazel.net>
Date: Sun, 25 Oct 2020 13:15:53 +0000 (+0100)
Subject: pknlusr: do not treat recv return value of zero as an error
X-Git-Tag: v3.12~15
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3c120ef5f199ed2c3cc315cf5f704b8ec886d31f;p=thirdparty%2Fxtables-addons.git

pknlusr: do not treat recv return value of zero as an error

A return-value of zero is not an error, so there is no point calling
perror, but since we have not requested and do not expect a zero-length
datagram, we treat it as EOF and exit.

Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
---

diff --git a/extensions/pknock/pknlusr.c b/extensions/pknock/pknlusr.c
index 16a9af9..81cfae0 100644
--- a/extensions/pknock/pknlusr.c
+++ b/extensions/pknock/pknlusr.c
@@ -51,10 +51,12 @@ int main(void)
 
 		memset(nlmsg, 0, nlmsg_size);
 		status = recv(sock_fd, nlmsg, nlmsg_size, 0);
-		if (status <= 0) {
+		if (status < 0) {
 			perror("recv()");
 			return 1;
 		}
+		if (status == 0)
+			break;
 		cn_msg = NLMSG_DATA(nlmsg);
 		pknock_msg = (struct xt_pknock_nl_msg *)(cn_msg->data);
 		ip = inet_ntop(AF_INET, &pknock_msg->peer_ip, ipbuf, sizeof(ipbuf));