From: Willy Tarreau <w@1wt.eu>
Date: Tue, 14 Mar 2017 13:50:52 +0000 (+0100)
Subject: CONTRIB: tcploop: use the trash instead of NULL for recv()
X-Git-Tag: v1.8-dev1~79
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a84a2dba946bd49676f5222d49eca8d40346e53c;p=thirdparty%2Fhaproxy.git

CONTRIB: tcploop: use the trash instead of NULL for recv()

NULL is Linux-centric and we're not focused on performance here but
portability and reproducibility. Don't use NULL and use the trash
instead. It may lead to multiple recv() calls for large blocks but
as a benefit it will be possible to see the contents with strace.
---

diff --git a/contrib/tcploop/tcploop.c b/contrib/tcploop/tcploop.c
index d1995f46e4..cb9e5f1246 100644
--- a/contrib/tcploop/tcploop.c
+++ b/contrib/tcploop/tcploop.c
@@ -444,6 +444,7 @@ int tcp_recv(int sock, const char *arg)
 {
 	int count = -1; // stop at first read
 	int ret;
+	int max;
 
 	if (arg[1]) {
 		count = atoi(arg + 1);
@@ -454,7 +455,10 @@ int tcp_recv(int sock, const char *arg)
 	}
 
 	while (1) {
-		ret = recv(sock, NULL, (count > 0) ? count : INT_MAX, MSG_NOSIGNAL | MSG_TRUNC);
+		max = (count > 0) ? count : INT_MAX;
+		if (max > sizeof(trash))
+			max = sizeof(trash);
+		ret = recv(sock, trash, max, MSG_NOSIGNAL | MSG_TRUNC);
 		if (ret < 0) {
 			if (errno == EINTR)
 				continue;