--- /dev/null
+/*
+ * 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/ktime.h>
+#include <linux/init.h>
+#include <linux/connector.h>
+#include <linux/gfp.h>
+#include <linux/ptrace.h>
+#include <linux/atomic.h>
+#include <linux/pid_namespace.h>
+
+#include <linux/cn_proc.h>
+
+/*
+ * Size of a cn_msg followed by a proc_event structure. Since the
+ * sizeof struct cn_msg is a multiple of 4 bytes, but not 8 bytes, we
+ * add one 4-byte word to the size here, and then start the actual
+ * cn_msg structure 4 bytes into the stack buffer. The result is that
+ * the immediately following proc_event structure is aligned to 8 bytes.
+ */
+#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event) + 4)
+
+/* See comment above; we test our assumption about sizeof struct cn_msg here. */
+static inline struct cn_msg *buffer_to_cn_msg(__u8 *buffer)
+{
+ BUILD_BUG_ON(sizeof(struct cn_msg) != 20);
+ return (struct cn_msg *)(buffer + 4);
+}
+
+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_event_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)
+{
+ preempt_disable();
+ *ts = __this_cpu_inc_return(proc_event_counts) - 1;
+ *cpu = smp_processor_id();
+ preempt_enable();
+}
+
+void proc_fork_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+ struct task_struct *parent;
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ ev->what = PROC_EVENT_FORK;
+ rcu_read_lock();
+ parent = rcu_dereference(task->real_parent);
+ ev->event_data.fork.parent_pid = parent->pid;
+ ev->event_data.fork.parent_tgid = parent->tgid;
+ rcu_read_unlock();
+ 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);
+ msg->flags = 0; /* not used */
+ /* If cn_netlink_send() failed, the data is not sent */
+ cn_netlink_send(msg, 0, 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] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ 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);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, 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] __aligned(8);
+ const struct cred *cred;
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ ev->what = which_id;
+ ev->event_data.id.process_pid = task->pid;
+ ev->event_data.id.process_tgid = task->tgid;
+ rcu_read_lock();
+ cred = __task_cred(task);
+ if (which_id == PROC_EVENT_UID) {
+ ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid);
+ ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid);
+ } else if (which_id == PROC_EVENT_GID) {
+ ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid);
+ ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid);
+ } else {
+ rcu_read_unlock();
+ return;
+ }
+ rcu_read_unlock();
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_sid_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ ev->what = PROC_EVENT_SID;
+ ev->event_data.sid.process_pid = task->pid;
+ ev->event_data.sid.process_tgid = task->tgid;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_ptrace_connector(struct task_struct *task, int ptrace_id)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ ev->what = PROC_EVENT_PTRACE;
+ ev->event_data.ptrace.process_pid = task->pid;
+ ev->event_data.ptrace.process_tgid = task->tgid;
+ if (ptrace_id == PTRACE_ATTACH) {
+ ev->event_data.ptrace.tracer_pid = current->pid;
+ ev->event_data.ptrace.tracer_tgid = current->tgid;
+ } else if (ptrace_id == PTRACE_DETACH) {
+ ev->event_data.ptrace.tracer_pid = 0;
+ ev->event_data.ptrace.tracer_tgid = 0;
+ } else
+ return;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_comm_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ ev->what = PROC_EVENT_COMM;
+ ev->event_data.comm.process_pid = task->pid;
+ ev->event_data.comm.process_tgid = task->tgid;
+ get_task_comm(ev->event_data.comm.comm, task);
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
+}
+
+void proc_coredump_connector(struct task_struct *task)
+{
+ struct cn_msg *msg;
+ struct proc_event *ev;
+ __u8 buffer[CN_PROC_MSG_SIZE] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ ev->what = PROC_EVENT_COREDUMP;
+ ev->event_data.coredump.process_pid = task->pid;
+ ev->event_data.coredump.process_tgid = task->tgid;
+
+ memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
+ msg->ack = 0; /* not used */
+ msg->len = sizeof(*ev);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, 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] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ get_seq(&msg->seq, &ev->cpu);
+ ev->timestamp_ns = ktime_get_ns();
+ 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);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, 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] __aligned(8);
+
+ if (atomic_read(&proc_event_num_listeners) < 1)
+ return;
+
+ msg = buffer_to_cn_msg(buffer);
+ ev = (struct proc_event *)msg->data;
+ memset(&ev->event_data, 0, sizeof(ev->event_data));
+ msg->seq = rcvd_seq;
+ ev->timestamp_ns = ktime_get_ns();
+ 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);
+ msg->flags = 0; /* not used */
+ cn_netlink_send(msg, 0, CN_IDX_PROC, GFP_KERNEL);
+}
+
+/**
+ * cn_proc_mcast_ctl
+ * @data: message sent from userspace via the connector
+ */
+static void cn_proc_mcast_ctl(struct cn_msg *msg,
+ struct netlink_skb_parms *nsp)
+{
+ enum proc_cn_mcast_op *mc_op = NULL;
+ int err = 0;
+
+ if (msg->len != sizeof(*mc_op))
+ return;
+
+ /*
+ * Events are reported with respect to the initial pid
+ * and user namespaces so ignore requestors from
+ * other namespaces.
+ */
+ if ((current_user_ns() != &init_user_ns) ||
+ (task_active_pid_ns(current) != &init_pid_ns))
+ return;
+
+ /* Can only change if privileged. */
+ if (!__netlink_ns_capable(nsp, &init_user_ns, CAP_NET_ADMIN)) {
+ err = EPERM;
+ goto out;
+ }
+
+ 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;
+ }
+
+out:
+ 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 = cn_add_callback(&cn_proc_event_id,
+ "cn_proc",
+ &cn_proc_mcast_ctl);
+ if (err) {
+ pr_warn("cn_proc failed to register\n");
+ return err;
+ }
+ return 0;
+}
+
+module_init(cn_proc_init);
Code Review / kvmfornfv.git / blobdiff