From 55e24f6e773b7c824eb06276faf1386b20bf7440 Mon Sep 17 00:00:00 2001
From: Diomidis Spinellis <dds@FreeBSD.org>
Date: Wed, 23 Jul 2003 22:00:08 +0000
Subject: [PATCH] Document an additional error return value.  The connect(2)
 call can also return EACCES on non-Unix domain sockets as demonstrated by the
 following program:

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

int
main(int argc, char *argv[])
{
	struct sockaddr_in rem_addr;
	int sock;

	if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
		perror("socket");
		exit(1);
	}

	bzero((char *)&rem_addr, sizeof(rem_addr));
	rem_addr.sin_family = AF_INET;
	rem_addr.sin_addr.s_addr = INADDR_NONE;
	rem_addr.sin_port = htons(10000);

	if (connect(sock, (struct sockaddr *)&rem_addr,
sizeof(rem_addr)) < 0) {
		perror("connect");
		exit(1);
	}
}

The call chain returning this value is probably:

kern/uipc_syscalls.c:connect
kern/uipc_socket.c:soconnect
netinet/tcp_usrreq.c:tcp_usr_connect
netinet/tcp_output.c:tcp_output
netinet/ip_output.c:ip_output

Reviewed by:	schweikh (mentor)
MFC after:	2 weeks
---
 lib/libc/sys/connect.2 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/lib/libc/sys/connect.2 b/lib/libc/sys/connect.2
index cfc6460d768..18a656b277a 100644
--- a/lib/libc/sys/connect.2
+++ b/lib/libc/sys/connect.2
@@ -121,6 +121,12 @@ for completion by selecting the socket for writing.
 The socket is non-blocking
 and a previous connection attempt
 has not yet been completed.
+.It Bq Er EACCES
+An attempt is made to connect to a broadcast address (obtained through the
+.Dv INADDR_BROADCAST 
+constant or the
+.Dv INADDR_NONE
+return value) through a socket that does not provide broadcast functionality.
 .El
 .Pp
 The following errors are specific to connecting names in the UNIX domain.