ioctl: The POSIX signature differs from BSD and glibc

BSD and glibc have the signature for request as unsigned long.
musl and Solaris have a signed int.

As such, we need to detect this at compile time and adjust the
signature of our internal ioctl functions to match.
To keep the onwire format the same, memcpy the request to the
unsigned long request and back again, thus preserving the signedness.

1 files changed, 21 insertions, 1 deletions

diff --git a/src/privsep-root.c b/src/privsep-root.c
index dd60a4ff..47363624 100644
--- a/src/privsep-root.c
+++ b/src/privsep-root.c
@@ -46,6 +46,8 @@
 #include "privsep.h"
 #include "script.h"
 
+__CTASSERT(sizeof(ioctl_request_t) <= sizeof(unsigned long));
+
 struct psr_error
 {
 	ssize_t psr_result;
@@ -130,7 +132,16 @@ ps_root_doioctl(unsigned long req, void *data, size_t len)
 
 	s = socket(PF_INET, SOCK_DGRAM, 0);
 	if (s != -1)
+#ifdef IOCTL_REQUEST_TYPE
+	{
+		ioctl_request_t reqt;
+
+		memcpy(&reqt, &req, sizeof(reqt));
+		err = ioctl(s, reqt, data, len);
+	}
+#else
 		err = ioctl(s, req, data, len);
+#endif
 	else
 		err = -1;
 	if (s != -1)
@@ -410,9 +421,18 @@ ps_root_script(const struct interface *ifp, const void *data, size_t len)
 }
 
 ssize_t
-ps_root_ioctl(struct dhcpcd_ctx *ctx, unsigned long req, void *data, size_t len)
+ps_root_ioctl(struct dhcpcd_ctx *ctx, ioctl_request_t req, void *data,
+    size_t len)
 {
+#ifdef IOCTL_REQUEST_TYPE
+	unsigned long ulreq = 0;
+
+	memcpy(&ulreq, &req, sizeof(req));
+	if (ps_sendcmd(ctx, ctx->ps_root_fd, PS_IOCTL, ulreq, data, len) == -1)
+		return -1;
+#else
 	if (ps_sendcmd(ctx, ctx->ps_root_fd, PS_IOCTL, req, data, len) == -1)
 		return -1;
+#endif
 	return ps_root_readerror(ctx);
 }