drivers/connector/cn_proc.c

   1 /*
   2  * cn_proc.c - process events connector
   3  *
   4  * Copyright (C) Matt Helsley, IBM Corp. 2005
   5  * Based on cn_fork.c by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
   6  * Original copyright notice follows:
   7  * Copyright (C) 2005 BULL SA.
   8  *
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  23  */
  24
  25 #include <linux/module.h>
  26 #include <linux/kernel.h>
  27 #include <linux/ktime.h>
  28 #include <linux/init.h>
  29 #include <linux/connector.h>
  30 #include <asm/atomic.h>
  31 #include <asm/unaligned.h>
  32
  33 #include <linux/cn_proc.h>
  34
  35 #define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event))
  36
  37 static atomic_t proc_event_num_listeners = ATOMIC_INIT(0);
  38 static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC };
  39
  40 /* proc_event_counts is used as the sequence number of the netlink message */
  41 static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 };
  42
  43 static inline void get_seq(__u32 *ts, int *cpu)
  44 {
  45         *ts = get_cpu_var(proc_event_counts)++;
  46         *cpu = smp_processor_id();
  47         put_cpu_var(proc_event_counts);
  48 }
  49
  50 void proc_fork_connector(struct task_struct *task)
  51 {
  52         struct cn_msg *msg;
  53         struct proc_event *ev;
  54         __u8 buffer[CN_PROC_MSG_SIZE];
  55         struct timespec ts;
  56
  57         if (atomic_read(&proc_event_num_listeners) < 1)
  58                 return;
  59
  60         msg = (struct cn_msg*)buffer;
  61         ev = (struct proc_event*)msg->data;
  62         get_seq(&msg->seq, &ev->cpu);
  63         ktime_get_ts(&ts); /* get high res monotonic timestamp */
  64         put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
  65         ev->what = PROC_EVENT_FORK;
  66         ev->event_data.fork.parent_pid = task->real_parent->pid;
  67         ev->event_data.fork.parent_tgid = task->real_parent->tgid;
  68         ev->event_data.fork.child_pid = task->pid;
  69         ev->event_data.fork.child_tgid = task->tgid;
  70
  71         memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
  72         msg->ack = 0; /* not used */
  73         msg->len = sizeof(*ev);
  74         /*  If cn_netlink_send() failed, the data is not sent */
  75         cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
  76 }
  77
  78 void proc_exec_connector(struct task_struct *task)
  79 {
  80         struct cn_msg *msg;
  81         struct proc_event *ev;
  82         struct timespec ts;
  83         __u8 buffer[CN_PROC_MSG_SIZE];
  84
  85         if (atomic_read(&proc_event_num_listeners) < 1)
  86                 return;
  87
  88         msg = (struct cn_msg*)buffer;
  89         ev = (struct proc_event*)msg->data;
  90         get_seq(&msg->seq, &ev->cpu);
  91         ktime_get_ts(&ts); /* get high res monotonic timestamp */
  92         put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
  93         ev->what = PROC_EVENT_EXEC;
  94         ev->event_data.exec.process_pid = task->pid;
  95         ev->event_data.exec.process_tgid = task->tgid;
  96
  97         memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
  98         msg->ack = 0; /* not used */
  99         msg->len = sizeof(*ev);
 100         cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 101 }
 102
 103 void proc_id_connector(struct task_struct *task, int which_id)
 104 {
 105         struct cn_msg *msg;
 106         struct proc_event *ev;
 107         __u8 buffer[CN_PROC_MSG_SIZE];
 108         struct timespec ts;
 109
 110         if (atomic_read(&proc_event_num_listeners) < 1)
 111                 return;
 112
 113         msg = (struct cn_msg*)buffer;
 114         ev = (struct proc_event*)msg->data;
 115         ev->what = which_id;
 116         ev->event_data.id.process_pid = task->pid;
 117         ev->event_data.id.process_tgid = task->tgid;
 118         if (which_id == PROC_EVENT_UID) {
 119                 ev->event_data.id.r.ruid = task->uid;
 120                 ev->event_data.id.e.euid = task->euid;
 121         } else if (which_id == PROC_EVENT_GID) {
 122                 ev->event_data.id.r.rgid = task->gid;
 123                 ev->event_data.id.e.egid = task->egid;
 124         } else
 125                 return;
 126         get_seq(&msg->seq, &ev->cpu);
 127         ktime_get_ts(&ts); /* get high res monotonic timestamp */
 128         put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
 129
 130         memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 131         msg->ack = 0; /* not used */
 132         msg->len = sizeof(*ev);
 133         cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 134 }
 135
 136 void proc_exit_connector(struct task_struct *task)
 137 {
 138         struct cn_msg *msg;
 139         struct proc_event *ev;
 140         __u8 buffer[CN_PROC_MSG_SIZE];
 141         struct timespec ts;
 142
 143         if (atomic_read(&proc_event_num_listeners) < 1)
 144                 return;
 145
 146         msg = (struct cn_msg*)buffer;
 147         ev = (struct proc_event*)msg->data;
 148         get_seq(&msg->seq, &ev->cpu);
 149         ktime_get_ts(&ts); /* get high res monotonic timestamp */
 150         put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
 151         ev->what = PROC_EVENT_EXIT;
 152         ev->event_data.exit.process_pid = task->pid;
 153         ev->event_data.exit.process_tgid = task->tgid;
 154         ev->event_data.exit.exit_code = task->exit_code;
 155         ev->event_data.exit.exit_signal = task->exit_signal;
 156
 157         memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 158         msg->ack = 0; /* not used */
 159         msg->len = sizeof(*ev);
 160         cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 161 }
 162
 163 /*
 164  * Send an acknowledgement message to userspace
 165  *
 166  * Use 0 for success, EFOO otherwise.
 167  * Note: this is the negative of conventional kernel error
 168  * values because it's not being returned via syscall return
 169  * mechanisms.
 170  */
 171 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack)
 172 {
 173         struct cn_msg *msg;
 174         struct proc_event *ev;
 175         __u8 buffer[CN_PROC_MSG_SIZE];
 176         struct timespec ts;
 177
 178         if (atomic_read(&proc_event_num_listeners) < 1)
 179                 return;
 180
 181         msg = (struct cn_msg*)buffer;
 182         ev = (struct proc_event*)msg->data;
 183         msg->seq = rcvd_seq;
 184         ktime_get_ts(&ts); /* get high res monotonic timestamp */
 185         put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns);
 186         ev->cpu = -1;
 187         ev->what = PROC_EVENT_NONE;
 188         ev->event_data.ack.err = err;
 189         memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id));
 190         msg->ack = rcvd_ack + 1;
 191         msg->len = sizeof(*ev);
 192         cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL);
 193 }
 194
 195 /**
 196  * cn_proc_mcast_ctl
 197  * @data: message sent from userspace via the connector
 198  */
 199 static void cn_proc_mcast_ctl(void *data)
 200 {
 201         struct cn_msg *msg = data;
 202         enum proc_cn_mcast_op *mc_op = NULL;
 203         int err = 0;
 204
 205         if (msg->len != sizeof(*mc_op))
 206                 return;
 207
 208         mc_op = (enum proc_cn_mcast_op*)msg->data;
 209         switch (*mc_op) {
 210         case PROC_CN_MCAST_LISTEN:
 211                 atomic_inc(&proc_event_num_listeners);
 212                 break;
 213         case PROC_CN_MCAST_IGNORE:
 214                 atomic_dec(&proc_event_num_listeners);
 215                 break;
 216         default:
 217                 err = EINVAL;
 218                 break;
 219         }
 220         cn_proc_ack(err, msg->seq, msg->ack);
 221 }
 222
 223 /*
 224  * cn_proc_init - initialization entry point
 225  *
 226  * Adds the connector callback to the connector driver.
 227  */
 228 static int __init cn_proc_init(void)
 229 {
 230         int err;
 231
 232         if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc",
 233                                    &cn_proc_mcast_ctl))) {
 234                 printk(KERN_WARNING "cn_proc failed to register\n");
 235                 return err;
 236         }
 237         return 0;
 238 }
 239
 240 module_init(cn_proc_init);