From a22936e4b3a7a9bc6eca434f8be3ef6dfd06d35d Mon Sep 17 00:00:00 2001
From: Roy Marples <roy@marples.name>
Date: Tue, 30 Aug 2022 15:52:21 +0100
Subject: [PATCH] Fix prior for Linux.

---
 src/if-linux.c      | 10 ++++++++++
 src/privsep-linux.c |  4 ++--
 src/privsep-root.c  | 11 +++--------
 3 files changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/if-linux.c b/src/if-linux.c
index 655750a2..e4a16044 100644
--- a/src/if-linux.c
+++ b/src/if-linux.c
@@ -439,6 +439,13 @@ if_opensockets_os(struct dhcpcd_ctx *ctx)
 	int on = 1;
 #endif
 
+#ifdef PRIVSEP
+	if (ctx->options & DHCPCD_PRIVSEPROOT) {
+		ctx->link_fd = -1;
+		goto setup_priv;
+	}
+#endif
+
 	/* Open the link socket first so it gets pid() for the socket.
 	 * Then open our persistent route socket so we get a unique
 	 * pid that doesn't clash with a process id for after we fork. */
@@ -461,6 +468,9 @@ if_opensockets_os(struct dhcpcd_ctx *ctx)
 		logerr("%s: NETLINK_BROADCAST_ERROR", __func__);
 #endif
 
+#ifdef PRIVSEP
+setup_priv:
+#endif
 	if ((priv = calloc(1, sizeof(*priv))) == NULL)
 		return -1;
 
diff --git a/src/privsep-linux.c b/src/privsep-linux.c
index 68f78297..d4439634 100644
--- a/src/privsep-linux.c
+++ b/src/privsep-linux.c
@@ -72,7 +72,7 @@ ps_root_dosendnetlink(struct dhcpcd_ctx *ctx, int protocol, struct msghdr *msg)
 
 	switch(protocol) {
 	case NETLINK_GENERIC:
-		s = priv->netlink_fd;
+		s = priv->generic_fd;
 		break;
 	case NETLINK_ROUTE:
 		s = priv->route_fd;
@@ -83,7 +83,7 @@ ps_root_dosendnetlink(struct dhcpcd_ctx *ctx, int protocol, struct msghdr *msg)
 	}
 
 	if (sendmsg(s, msg, 0) == -1)
-		return =-1;
+		return -1;
 
 	return if_getnetlink(NULL, &riov, s, 0, NULL, NULL);
 }
diff --git a/src/privsep-root.c b/src/privsep-root.c
index 7bf2e068..a8290a40 100644
--- a/src/privsep-root.c
+++ b/src/privsep-root.c
@@ -669,8 +669,8 @@ ps_root_startcb(struct ps_process *psp)
 
 	if (if_opensockets(ctx) == -1)
 		logerr("%s: if_opensockets", __func__);
-	else {
 #ifdef BSD
+	else {
 		/* We only want to write to this socket, so set
 		 * a small as possible buffer size. */
 		socklen_t smallbuf = 1;
@@ -678,14 +678,8 @@ ps_root_startcb(struct ps_process *psp)
 		if (setsockopt(ctx->link_fd, SOL_SOCKET, SO_RCVBUF,
 		    &smallbuf, (socklen_t)sizeof(smallbuf)) == -1)
 			logerr("%s: setsockopt(SO_RCVBUF)", __func__);
-#endif
-#ifdef __linux__
-		/* See if_opensockets_os as to why we close link_fd
-		 * rather than not open it. */
-		close(ctx->link_fd);
-		ctx->link_fd = -1;
-#endif
 	}
+#endif
 
 	/* Open network sockets for sending.
 	 * This is a small bit wasteful for non sandboxed OS's
@@ -740,6 +734,7 @@ ps_root_startcb(struct ps_process *psp)
 	    (DHCPCD_MANAGER | DHCPCD_DEV))
 		dev_start(ctx, ps_root_handleinterface);
 #endif
+
 	return 0;
 }
 
-- 
2.47.2