From 2d3f8a411f764ec3cfca5e2a31ef682e8144056d Mon Sep 17 00:00:00 2001
From: William Lallemand <wlallemand@haproxy.com>
Date: Tue, 11 Sep 2018 16:51:28 +0200
Subject: [PATCH] MEDIUM: protocol: use a custom AF_MAX to help protocol parser

It's possible to have several protocols per family which is a problem
with the current way the protocols are stored.

This allows to register a new protocol in HAProxy which is not a
protocol in the strict socket definition. It will be used to register a
SOCK_STREAM protocol using socketpair().
---
 include/proto/protocol.h |  4 ++--
 include/types/protocol.h | 17 +++++++++++++++++
 src/protocol.c           |  4 ++--
 3 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/include/proto/protocol.h b/include/proto/protocol.h
index 13a3c0a61..857f9e692 100644
--- a/include/proto/protocol.h
+++ b/include/proto/protocol.h
@@ -25,7 +25,7 @@
 #include <sys/socket.h>
 #include <types/protocol.h>
 
-extern struct protocol *__protocol_by_family[AF_MAX];
+extern struct protocol *__protocol_by_family[AF_CUST_MAX];
 
 /* Registers the protocol <proto> */
 void protocol_register(struct protocol *proto);
@@ -56,7 +56,7 @@ int protocol_enable_all(void);
 /* returns the protocol associated to family <family> or NULL if not found */
 static inline struct protocol *protocol_by_family(int family)
 {
-	if (family >= 0 && family < AF_MAX)
+	if (family >= 0 && family < AF_CUST_MAX)
 		return __protocol_by_family[family];
 	return NULL;
 }
diff --git a/include/types/protocol.h b/include/types/protocol.h
index 9480c1869..378e2b0e1 100644
--- a/include/types/protocol.h
+++ b/include/types/protocol.h
@@ -33,6 +33,23 @@
 struct listener;
 struct connection;
 
+/*
+ * Custom network family for str2sa parsing.  Should be ok to do this since
+ * sa_family_t is standardized as an unsigned integer
+ */
+
+#define AF_CUST_SOCKPAIR     (AF_MAX + 1)
+#define AF_CUST_MAX          (AF_MAX + 2)
+
+/*
+ * Test in case AF_CUST_MAX overflows the sa_family_t (unsigned int)
+ */
+#if (AF_CUST_MAX < AF_MAX)
+# error "Can't build on the target system, AF_CUST_MAX overflow"
+#endif
+
+
+
 /* max length of a protcol name, including trailing zero */
 #define PROTO_NAME_LEN 16
 
diff --git a/src/protocol.c b/src/protocol.c
index 7884ef734..96e01c827 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -22,13 +22,13 @@
 
 /* List head of all registered protocols */
 static struct list protocols = LIST_HEAD_INIT(protocols);
-struct protocol *__protocol_by_family[AF_MAX] = { };
+struct protocol *__protocol_by_family[AF_CUST_MAX] = { };
 
 /* Registers the protocol <proto> */
 void protocol_register(struct protocol *proto)
 {
 	LIST_ADDQ(&protocols, &proto->list);
-	if (proto->sock_domain >= 0 && proto->sock_domain < AF_MAX)
+	if (proto->sock_domain >= 0 && proto->sock_domain < AF_CUST_MAX)
 		__protocol_by_family[proto->sock_domain] = proto;
 }