Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

include/net/scm.h

@@ -0,0 +1,71 @@
+#ifndef __LINUX_NET_SCM_H
+#define __LINUX_NET_SCM_H
+
+#include <linux/limits.h>
+#include <linux/net.h>
+
+/* Well, we should have at least one descriptor open
+ * to accept passed FDs 8)
+ */
+#define SCM_MAX_FD	(OPEN_MAX-1)
+
+struct scm_fp_list
+{
+	int		count;
+	struct file	*fp[SCM_MAX_FD];
+};
+
+struct scm_cookie
+{
+	struct ucred		creds;		/* Skb credentials	*/
+	struct scm_fp_list	*fp;		/* Passed files		*/
+	unsigned long		seq;		/* Connection seqno	*/
+};
+
+extern void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm);
+extern void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm);
+extern int __scm_send(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm);
+extern void __scm_destroy(struct scm_cookie *scm);
+extern struct scm_fp_list * scm_fp_dup(struct scm_fp_list *fpl);
+
+static __inline__ void scm_destroy(struct scm_cookie *scm)
+{
+	if (scm && scm->fp)
+		__scm_destroy(scm);
+}
+
+static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
+			       struct scm_cookie *scm)
+{
+	memset(scm, 0, sizeof(*scm));
+	scm->creds.uid = current->uid;
+	scm->creds.gid = current->gid;
+	scm->creds.pid = current->tgid;
+	if (msg->msg_controllen <= 0)
+		return 0;
+	return __scm_send(sock, msg, scm);
+}
+
+static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg,
+				struct scm_cookie *scm, int flags)
+{
+	if (!msg->msg_control)
+	{
+		if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp)
+			msg->msg_flags |= MSG_CTRUNC;
+		scm_destroy(scm);
+		return;
+	}
+
+	if (test_bit(SOCK_PASSCRED, &sock->flags))
+		put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(scm->creds), &scm->creds);
+
+	if (!scm->fp)
+		return;
+	
+	scm_detach_fds(msg, scm);
+}
+
+
+#endif /* __LINUX_NET_SCM_H */
+