commit 3cd58bf80555fd22687a11672d5c0dd4c11c2089
author Willy Tarreau <w@1wt.eu> Thu Sep 17 08:35:38 2020 +0200
committer Willy Tarreau <w@1wt.eu> Thu Sep 17 08:35:38 2020 +0200
tree 79646dfd37afb90bf102171c86c67cf0507b161d
parent 36722d2274127ef91959296bb5299c8120b16ce7

MINOR: sock_unix: report the errno string in binding errors

Just like with previous patch, let's report UNIX socket binding errors
in plain text. we can now see for example:

  [ALERT] 260/083531 (13365) : Starting frontend f: cannot switch final and temporary UNIX sockets (Operation not permitted) [/tmp/root.sock]
  [ALERT] 260/083640 (13375) : Starting frontend f: cannot change UNIX socket ownership (Operation not permitted) [/tmp/root.sock]

src/sock_unix.c

diff --git a/src/sock_unix.c b/src/sock_unix.c
index cf3e49c..a3056df 100644
--- a/src/sock_unix.c
+++ b/src/sock_unix.c
@@ -178,20 +178,20 @@
 		/* 2. clean existing orphaned entries */
 		if (unlink(tempname) < 0 && errno != ENOENT) {
 			err |= ERR_FATAL | ERR_ALERT;
-			memprintf(errmsg, "error when trying to unlink previous UNIX socket");
+			memprintf(errmsg, "error when trying to unlink previous UNIX socket (%s)", strerror(errno));
 			goto bind_return;
 		}
 
 		if (unlink(backname) < 0 && errno != ENOENT) {
 			err |= ERR_FATAL | ERR_ALERT;
-			memprintf(errmsg, "error when trying to unlink previous UNIX socket");
+			memprintf(errmsg, "error when trying to unlink previous UNIX socket (%s)", strerror(errno));
 			goto bind_return;
 		}
 
 		/* 3. backup existing socket */
 		if (link(path, backname) < 0 && errno != ENOENT) {
 			err |= ERR_FATAL | ERR_ALERT;
-			memprintf(errmsg, "error when trying to preserve previous UNIX socket");
+			memprintf(errmsg, "error when trying to preserve previous UNIX socket (%s)", strerror(errno));
 			goto bind_return;
 		}
 
@@ -222,7 +222,7 @@
 	fd = socket(rx->proto->fam->sock_domain, rx->proto->sock_type, rx->proto->sock_prot);
 	if (fd < 0) {
 		err |= ERR_FATAL | ERR_ALERT;
-		memprintf(errmsg, "cannot create receiving socket");
+		memprintf(errmsg, "cannot create receiving socket (%s)", strerror(errno));
 		goto bind_return;
 	}
 
@@ -249,7 +249,7 @@
 		}
 		else {
 			err |= ERR_FATAL | ERR_ALERT;
-			memprintf(errmsg, "cannot bind UNIX socket");
+			memprintf(errmsg, "cannot bind UNIX socket (%s)", strerror(errno));
 			goto bind_close_return;
 		}
 		goto err_unlink_temp;
@@ -265,7 +265,7 @@
 	      (chown(tempname, rx->settings->ux.uid, rx->settings->ux.gid) == -1)) ||
 	     (rx->settings->ux.mode != 0 && chmod(tempname, rx->settings->ux.mode) == -1))) {
 		err |= ERR_FATAL | ERR_ALERT;
-		memprintf(errmsg, "cannot change UNIX socket ownership");
+		memprintf(errmsg, "cannot change UNIX socket ownership (%s)", strerror(errno));
 		goto err_unlink_temp;
 	}
 
@@ -275,7 +275,7 @@
 	 */
 	if (!ext && path[0] && rename(tempname, path) < 0) {
 		err |= ERR_FATAL | ERR_ALERT;
-		memprintf(errmsg, "cannot switch final and temporary UNIX sockets");
+		memprintf(errmsg, "cannot switch final and temporary UNIX sockets (%s)", strerror(errno));
 		goto err_rename;
 	}