Add support for HTTP/1.0 Persistent Connections to phttpget. Requests are

be marked as HTTP/1.1 but "Connection: Keep-Alive" is added; this convinces
HTTP/1.0 servers and proxies to hold the TCP connection open despite not
being able to use HTTP pipelining.

This dramatically cuts down on the number of TCP connections (and thus port
numbers) used by portsnap when talking to an HTTP/1.0 proxy (e.g., squid),
and has the side benefit of improving performance in those cases.

Tested by:	simon
Approved by:	re (kensmith)
MFC After:	1 week

1 files changed, 10 insertions, 3 deletions

diff --git a/usr.sbin/portsnap/phttpget/phttpget.c b/usr.sbin/portsnap/phttpget/phttpget.c
index 315af00..ffd14c3 100644
--- a/usr.sbin/portsnap/phttpget/phttpget.c
+++ b/usr.sbin/portsnap/phttpget/phttpget.c
@@ -211,7 +211,7 @@ makerequest(char ** buf, char * path, char * server, int connclose)
 	    env_HTTP_PROXY ? server : "",
 	    path, server, env_HTTP_USER_AGENT,
 	    proxyauth ? proxyauth : "",
-	    connclose ? "Connection: Close\r\n" : "");
+	    connclose ? "Connection: Close\r\n" : "Connection: Keep-Alive\r\n");
 	if (buflen == -1)
 		err(1, "asprintf");
 	return(buflen);
@@ -307,6 +307,7 @@ main(int argc, char *argv[])
 	int nreq = 0;		/* Number of next request to send */
 	int nres = 0;		/* Number of next reply to receive */
 	int pipelined = 0;	/* != 0 if connection in pipelined mode. */
+	int keepalive;		/* != 0 if HTTP/1.0 keep-alive rcvd. */
 	int sd = -1;		/* Socket descriptor */
 	int sdflags = 0;	/* Flags on the socket sd */
 	int fd = -1;		/* Descriptor for download target file */
@@ -444,6 +445,7 @@ main(int argc, char *argv[])
 		statuscode = 0;
 		contentlength = -1;
 		chunked = 0;
+		keepalive = 0;
 		do {
 			/* Get a header line */
 			error = readln(sd, resbuf, &resbuflen, &resbufpos);
@@ -497,11 +499,16 @@ main(int argc, char *argv[])
 				continue;
 			}
 
-			/* Check for "Connection: close" header */
+			/*
+			 * Check for "Connection: close" or
+			 * "Connection: Keep-Alive" header
+			 */
 			if (strncmp(hln, "Connection:", 11) == 0) {
 				hln += 11;
 				if (strstr(hln, "close") != NULL)
 					pipelined = 0;
+				if (strstr(hln, "Keep-Alive") != NULL)
+					keepalive = 1;
 
 				/* Next header... */
 				continue;
@@ -673,7 +680,7 @@ main(int argc, char *argv[])
 		 * If necessary, clean up this connection so that we
 		 * can start a new one.
 		 */
-		if (pipelined == 0)
+		if (pipelined == 0 && keepalive == 0)
 			goto cleanupconn;
 		continue;