1 files changed, 130 insertions, 0 deletions
diff --git a/include/net/scm.h b/include/net/scm.h
new file mode 100644
index 00000000..745460fa
--- /dev/null
+++ b/include/net/scm.h
@@ -0,0 +1,130 @@
+#ifndef __LINUX_NET_SCM_H
+#define __LINUX_NET_SCM_H
+
+#include <linux/limits.h>
+#include <linux/net.h>
+#include <linux/security.h>
+#include <linux/pid.h>
+#include <linux/nsproxy.h>
+
+/* Well, we should have at least one descriptor open
+ * to accept passed FDs 8)
+ */
+#define SCM_MAX_FD	253
+
+struct scm_fp_list {
+	struct list_head	list;
+	short			count;
+	short			max;
+	struct file		*fp[SCM_MAX_FD];
+};
+
+struct scm_cookie {
+	struct pid		*pid;		/* Skb credentials */
+	const struct cred	*cred;
+	struct scm_fp_list	*fp;		/* Passed files		*/
+	struct ucred		creds;		/* Skb credentials	*/
+#ifdef CONFIG_SECURITY_NETWORK
+	u32			secid;		/* Passed security ID 	*/
+#endif
+};
+
+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);
+
+#ifdef CONFIG_SECURITY_NETWORK
+static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
+{
+	security_socket_getpeersec_dgram(sock, NULL, &scm->secid);
+}
+#else
+static __inline__ void unix_get_peersec_dgram(struct socket *sock, struct scm_cookie *scm)
+{ }
+#endif /* CONFIG_SECURITY_NETWORK */
+
+static __inline__ void scm_set_cred(struct scm_cookie *scm,
+				    struct pid *pid, const struct cred *cred)
+{
+	scm->pid  = get_pid(pid);
+	scm->cred = get_cred(cred);
+	cred_to_ucred(pid, cred, &scm->creds);
+}
+
+static __inline__ void scm_destroy_cred(struct scm_cookie *scm)
+{
+	put_pid(scm->pid);
+	scm->pid  = NULL;
+
+	if (scm->cred)
+		put_cred(scm->cred);
+	scm->cred = NULL;
+}
+
+static __inline__ void scm_destroy(struct scm_cookie *scm)
+{
+	scm_destroy_cred(scm);
+	if (scm && scm->fp)
+		__scm_destroy(scm);
+}
+
+static __inline__ int scm_send(struct socket *sock, struct msghdr *msg,
+			       struct scm_cookie *scm)
+{
+	scm_set_cred(scm, task_tgid(current), current_cred());
+	scm->fp = NULL;
+	unix_get_peersec_dgram(sock, scm);
+	if (msg->msg_controllen <= 0)
+		return 0;
+	return __scm_send(sock, msg, scm);
+}
+
+#ifdef CONFIG_SECURITY_NETWORK
+static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
+{
+	char *secdata;
+	u32 seclen;
+	int err;
+
+	if (test_bit(SOCK_PASSSEC, &sock->flags)) {
+		err = security_secid_to_secctx(scm->secid, &secdata, &seclen);
+
+		if (!err) {
+			put_cmsg(msg, SOL_SOCKET, SCM_SECURITY, seclen, secdata);
+			security_release_secctx(secdata, seclen);
+		}
+	}
+}
+#else
+static inline void scm_passec(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm)
+{ }
+#endif /* CONFIG_SECURITY_NETWORK */
+
+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);
+
+	scm_destroy_cred(scm);
+
+	scm_passec(sock, msg, scm);
+
+	if (!scm->fp)
+		return;
+	
+	scm_detach_fds(msg, scm);
+}
+
+
+#endif /* __LINUX_NET_SCM_H */
+