From b7d5154c18cb57dd5680114315fbc4175cf1ea26 Mon Sep 17 00:00:00 2001
From: "Ned T. Crigler" <crigler@users.sourceforge.net>
Date: Mon, 4 Aug 2014 12:51:15 -0700
Subject: [PATCH] Try to use chdir to get around the sun_path length limit.

If a socket's path name would overflow sun_path, try to make it fit by
temporarily changing to the directory the socket is in and using the
path's basename in sun_path.

This should help for the case where the basename of the socket does fit
in sun_path, even if the rest of the path doesn't.
---
 attach.c | 22 ++++++++++++++++++++++
 master.c | 22 ++++++++++++++++++++++
 2 files changed, 44 insertions(+)

diff --git a/attach.c b/attach.c
index a4ae626..45788e2 100644
--- a/attach.c
+++ b/attach.c
@@ -156,6 +156,28 @@ attach_main(int noerror)
 	/* Attempt to open the socket. Don't display an error if noerror is 
 	** set. */
 	s = connect_socket(sockname);
+	if (s < 0 && errno == ENAMETOOLONG)
+	{
+		char *slash = strrchr(sockname, '/');
+
+		/* Try to shorten the socket's path name by using chdir. */
+		if (slash)
+		{
+			int dirfd = open(".", O_RDONLY);
+
+			if (dirfd >= 0)
+			{
+				*slash = '\0';
+				if (chdir(sockname) >= 0)
+				{
+					s = connect_socket(slash + 1);
+					fchdir(dirfd);
+				}
+				*slash = '/';
+				close(dirfd);
+			}
+		}
+	}
 	if (s < 0)
 	{
 		if (!noerror)
diff --git a/master.c b/master.c
index 86195d1..146110d 100644
--- a/master.c
+++ b/master.c
@@ -561,6 +561,28 @@ master_main(char **argv, int waitattach, int dontfork)
 
 	/* Create the unix domain socket. */
 	s = create_socket(sockname);
+	if (s < 0 && errno == ENAMETOOLONG)
+	{
+		char *slash = strrchr(sockname, '/');
+
+		/* Try to shorten the socket's path name by using chdir. */
+		if (slash)
+		{
+			int dirfd = open(".", O_RDONLY);
+
+			if (dirfd >= 0)
+			{
+				*slash = '\0';
+				if (chdir(sockname) >= 0)
+				{
+					s = create_socket(slash + 1);
+					fchdir(dirfd);
+				}
+				*slash = '/';
+				close(dirfd);
+			}
+		}
+	}
 	if (s < 0)
 	{
 		printf("%s: %s: %s\n", progname, sockname, strerror(errno));