[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>
diff --git a/drivers/connector/Kconfig b/drivers/connector/Kconfig
index 0bc2059..e0bdc0d 100644
--- a/drivers/connector/Kconfig
+++ b/drivers/connector/Kconfig
@@ -10,4 +10,12 @@
Connector support can also be built as a module. If so, the module
will be called cn.ko.
+config PROC_EVENTS
+ boolean "Report process events to userspace"
+ depends on CONNECTOR=y
+ default y
+ ---help---
+ Provide a connector that reports process events to userspace. Send
+ events such as fork, exec, id change (uid, gid, suid, etc), and exit.
+
endmenu
diff --git a/drivers/connector/Makefile b/drivers/connector/Makefile
index 12ca79e..1f255e4 100644
--- a/drivers/connector/Makefile
+++ b/drivers/connector/Makefile
@@ -1,3 +1,4 @@
obj-$(CONFIG_CONNECTOR) += cn.o
+obj-$(CONFIG_PROC_EVENTS) += cn_proc.o
cn-y += cn_queue.o connector.o
diff --git a/drivers/connector/cn_proc.c b/drivers/connector/cn_proc.c
new file mode 100644
index 0000000..fcdf0ff
--- /dev/null
+++ b/drivers/connector/cn_proc.c
@@ -0,0 +1,222 @@
+/*
+ * cn_proc.c - process events connector
+ *
+ * Copyright (C) Matt Helsley, IBM Corp. 2005
+ * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
+ * Original copyright notice follows:
+ * Copyright (C) 2005 BULL SA.
+ *
+ *
+ * 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
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <asm/atomic.h>
+
+#include <linux/cn_proc.h>
+
+#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
+
+static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
+static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
+
+/* proc_counts is used as the sequence number of the netlink message */
+static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
+
+static inline void get_seq(__u32 *ts, int *cpu)
+{
+ *ts = get_cpu_var(proc_event_counts)++;
+ *cpu = smp_processor_id();
+ put_cpu_var(proc_counts);
+}
+
+void proc_fork_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg*)buffer;
+ ev = (struct proc_event*)msg->data;
+ get_seq(&msg->seq, &ev->cpu);
+ ev->what = PROC_EVENT_FORK;
+ ev->event_data.fork.parent_pid = task->real_parent->pid;
+ ev->event_data.fork.parent_tgid = task->real_parent->tgid;
+ ev->event_data.fork.child_pid = task->pid;
+ ev->event_data.fork.child_tgid = task->tgid;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ /* If cn_netlink_send() failed, the data is not sent */
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_exec_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg*)buffer;
+ ev = (struct proc_event*)msg->data;
+ get_seq(&msg->seq, &ev->cpu);
+ ev->what = PROC_EVENT_EXEC;
+ ev->event_data.exec.process_pid = task->pid;
+ ev->event_data.exec.process_tgid = task->tgid;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_id_connector(struct task_struct *task, int which_id)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg*)buffer;
+ ev = (struct proc_event*)msg->data;
+ ev->what = which_id;
+ ev->event_data.id.process_pid = task->pid;
+ ev->event_data.id.process_tgid = task->tgid;
+ if (which_id == PROC_EVENT_UID) {
+ ev->event_data.id.r.ruid = task->uid;
+ ev->event_data.id.e.euid = task->euid;
+ } else if (which_id == PROC_EVENT_GID) {
+ ev->event_data.id.r.rgid = task->gid;
+ ev->event_data.id.e.egid = task->egid;
+ } else
+ return;
+ get_seq(&msg->seq, &ev->cpu);
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_exit_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg*)buffer;
+ ev = (struct proc_event*)msg->data;
+ get_seq(&msg->seq, &ev->cpu);
+ ev->what = PROC_EVENT_EXIT;
+ ev->event_data.exit.process_pid = task->pid;
+ ev->event_data.exit.process_tgid = task->tgid;
+ ev->event_data.exit.exit_code = task->exit_code;
+ ev->event_data.exit.exit_signal = task->exit_signal;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+/*
+ * Send an acknowledgement message to userspace
+ *
+ * Use 0 for success, EFOO otherwise.
+ * Note: this is the negative of conventional kernel error
+ * values because it's not being returned via syscall return
+ * mechanisms.
+ */
+static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE];
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = (struct cn_msg*)buffer;
+ ev = (struct proc_event*)msg->data;
+ msg->seq = rcvd_seq;
+ ev->cpu = -1;
+ ev->what = PROC_EVENT_NONE;
+ ev->event_data.ack.err = err;
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = rcvd_ack + 1;
+ msg->len = sizeof(*ev);
+ cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
+}
+
+/**
+ * cn_proc_mcast_ctl
+ * @data: message sent from userspace via the connector
+ */
+static void cn_proc_mcast_ctl(void *data)
+{
+ struct cn_msg *msg = data;
+ enum proc_cn_mcast_op *mc_op = NULL;
+ int err = 0;
+
+ if (msg->len != sizeof(*mc_op))
+ return;
+
+ mc_op = (enum proc_cn_mcast_op*)msg->data;
+ switch (*mc_op) {
+ case PROC_CN_MCAST_LISTEN:
+ atomic_inc(&proc_event_num_listeners);
+ break;
+ case PROC_CN_MCAST_IGNORE:
+ atomic_dec(&proc_event_num_listeners);
+ break;
+ default:
+ err = EINVAL;
+ break;
+ }
+ cn_proc_ack(err, msg->seq, msg->ack);
+}
+
+/*
+ * cn_proc_init - initialization entry point
+ *
+ * Adds the connector callback to the connector driver.
+ */
+static int __init cn_proc_init(void)
+{
+ int err;
+
+ if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
+ &cn_proc_mcast_ctl))) {
+ printk(KERN_WARNING "cn_proc failed to register\n");
+ return err;
+ }
+ return 0;
+}
+
+module_init(cn_proc_init);