[PATCH] Process Events Connector

This patch adds a connector that reports fork, exec, id change, and exit
events for all processes to userspace.  It replaces the fork_advisor patch
that ELSA is currently using.  Applications that may find these events
useful include accounting/auditing (e.g.  ELSA), system activity monitoring
(e.g.  top), security, and resource management (e.g.  CKRM).

Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 133 insertions, 0 deletions

diff --git a/include/linux/cn_proc.h b/include/linux/cn_proc.h
new file mode 100644
index 000000000000..70ab56317380
--- /dev/null
+++ b/include/linux/cn_proc.h
@@ -0,0 +1,127 @@
+/*
+ * cn_proc.h - process events connector
+ *
+ * Copyright (C) Matt Helsley, IBM Corp. 2005
+ * Based on cn_fork.h by Nguyen Anh Quynh and Guillaume Thouvenin
+ * Original copyright notice follows:
+ * Copyright (C) 2005 Nguyen Anh Quynh <aquynh@gmail.com>
+ * Copyright (C) 2005 Guillaume Thouvenin <guillaume.thouvenin@bull.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef CN_PROC_H
+#define CN_PROC_H
+
+#include <linux/types.h>
+#include <linux/connector.h>
+
+/*
+ * Userspace sends this enum to register with the kernel that it is listening
+ * for events on the connector.
+ */
+enum proc_cn_mcast_op {
+	PROC_CN_MCAST_LISTEN = 1,
+	PROC_CN_MCAST_IGNORE = 2
+};
+
+/*
+ * From the user's point of view, the process
+ * ID is the thread group ID and thread ID is the internal
+ * kernel "pid". So, fields are assigned as follow:
+ *
+ *  In user space     -  In  kernel space
+ *
+ * parent process ID  =  parent->tgid
+ * parent thread  ID  =  parent->pid
+ * child  process ID  =  child->tgid
+ * child  thread  ID  =  child->pid
+ */
+
+struct proc_event {
+	enum what {
+		/* Use successive bits so the enums can be used to record
+		 * sets of events as well
+		 */
+		PROC_EVENT_NONE = 0x00000000,
+		PROC_EVENT_FORK = 0x00000001,
+		PROC_EVENT_EXEC = 0x00000002,
+		PROC_EVENT_UID  = 0x00000004,
+		PROC_EVENT_GID  = 0x00000040,
+		/* "next" should be 0x00000400 */
+		/* "last" is the last process event: exit */
+		PROC_EVENT_EXIT = 0x80000000
+	} what;
+	__u32 cpu;
+	union { /* must be last field of proc_event struct */
+		struct {
+			__u32 err;
+		} ack;
+
+		struct fork_proc_event {
+			pid_t parent_pid;
+			pid_t parent_tgid;
+			pid_t child_pid;
+			pid_t child_tgid;
+		} fork;
+
+		struct exec_proc_event {
+			pid_t process_pid;
+			pid_t process_tgid;
+		} exec;
+
+		struct id_proc_event {
+			pid_t process_pid;
+			pid_t process_tgid;
+			union {
+				uid_t ruid; /* current->uid */
+				gid_t rgid; /* current->gid */
+			} r;
+			union {
+				uid_t euid;
+				gid_t egid;
+			} e;
+		} id;
+
+		struct exit_proc_event {
+			pid_t process_pid;
+			pid_t process_tgid;
+			__u32 exit_code, exit_signal;
+		} exit;
+	} event_data;
+};
+
+#ifdef __KERNEL__
+#ifdef CONFIG_PROC_EVENTS
+void proc_fork_connector(struct task_struct *task);
+void proc_exec_connector(struct task_struct *task);
+void proc_id_connector(struct task_struct *task, int which_id);
+void proc_exit_connector(struct task_struct *task);
+#else
+static inline void proc_fork_connector(struct task_struct *task)
+{}
+
+static inline void proc_exec_connector(struct task_struct *task)
+{}
+
+static inline void proc_id_connector(struct task_struct *task,
+				     int which_id)
+{}
+
+static inline void proc_exit_connector(struct task_struct *task)
+{}
+#endif	/* CONFIG_PROC_EVENTS */
+#endif	/* __KERNEL__ */
+#endif	/* CN_PROC_H */
diff --git a/include/linux/connector.h b/include/linux/connector.h
index 95952cc1f525..c5769c6585f4 100644
--- a/include/linux/connector.h
+++ b/include/linux/connector.h
@@ -27,6 +27,12 @@
 #define CN_IDX_CONNECTOR		0xffffffff
 #define CN_VAL_CONNECTOR		0xffffffff
 
+/*
+ * Process Events connector unique ids -- used for message routing
+ */
+#define CN_IDX_PROC			0x1
+#define CN_VAL_PROC			0x1
+
 #define CN_NETLINK_USERS		1
 
 /*