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 <linux/gfp.h> 31#include <asm/atomic.h> 32#include <asm/unaligned.h> 33 34#include <linux/cn_proc.h> 35 36#define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event)) 37 38static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); 39static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; 40 41/* proc_event_counts is used as the sequence number of the netlink message */ 42static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; 43 44static inline void get_seq(__u32 *ts, int *cpu) 45{ 46 *ts = get_cpu_var(proc_event_counts)++; 47 *cpu = smp_processor_id(); 48 put_cpu_var(proc_event_counts); 49} 50 51void proc_fork_connector(struct task_struct *task) 52{ 53 struct cn_msg *msg; 54 struct proc_event *ev; 55 __u8 buffer[CN_PROC_MSG_SIZE]; 56 struct timespec ts; 57 58 if (atomic_read(&proc_event_num_listeners) < 1) 59 return; 60 61 msg = (struct cn_msg*)buffer; 62 ev = (struct proc_event*)msg->data; 63 get_seq(&msg->seq, &ev->cpu); 64 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 65 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 66 ev->what = PROC_EVENT_FORK; 67 ev->event_data.fork.parent_pid = task->real_parent->pid; 68 ev->event_data.fork.parent_tgid = task->real_parent->tgid; 69 ev->event_data.fork.child_pid = task->pid; 70 ev->event_data.fork.child_tgid = task->tgid; 71 72 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 73 msg->ack = 0; /* not used */ 74 msg->len = sizeof(*ev); 75 /* If cn_netlink_send() failed, the data is not sent */ 76 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 77} 78 79void proc_exec_connector(struct task_struct *task) 80{ 81 struct cn_msg *msg; 82 struct proc_event *ev; 83 struct timespec ts; 84 __u8 buffer[CN_PROC_MSG_SIZE]; 85 86 if (atomic_read(&proc_event_num_listeners) < 1) 87 return; 88 89 msg = (struct cn_msg*)buffer; 90 ev = (struct proc_event*)msg->data; 91 get_seq(&msg->seq, &ev->cpu); 92 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 93 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 94 ev->what = PROC_EVENT_EXEC; 95 ev->event_data.exec.process_pid = task->pid; 96 ev->event_data.exec.process_tgid = task->tgid; 97 98 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 99 msg->ack = 0; /* not used */ 100 msg->len = sizeof(*ev); 101 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 102} 103 104void proc_id_connector(struct task_struct *task, int which_id) 105{ 106 struct cn_msg *msg; 107 struct proc_event *ev; 108 __u8 buffer[CN_PROC_MSG_SIZE]; 109 struct timespec ts; 110 const struct cred *cred; 111 112 if (atomic_read(&proc_event_num_listeners) < 1) 113 return; 114 115 msg = (struct cn_msg*)buffer; 116 ev = (struct proc_event*)msg->data; 117 ev->what = which_id; 118 ev->event_data.id.process_pid = task->pid; 119 ev->event_data.id.process_tgid = task->tgid; 120 rcu_read_lock(); 121 cred = __task_cred(task); 122 if (which_id == PROC_EVENT_UID) { 123 ev->event_data.id.r.ruid = cred->uid; 124 ev->event_data.id.e.euid = cred->euid; 125 } else if (which_id == PROC_EVENT_GID) { 126 ev->event_data.id.r.rgid = cred->gid; 127 ev->event_data.id.e.egid = cred->egid; 128 } else { 129 rcu_read_unlock(); 130 return; 131 } 132 rcu_read_unlock(); 133 get_seq(&msg->seq, &ev->cpu); 134 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 135 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 136 137 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 138 msg->ack = 0; /* not used */ 139 msg->len = sizeof(*ev); 140 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 141} 142 143void proc_sid_connector(struct task_struct *task) 144{ 145 struct cn_msg *msg; 146 struct proc_event *ev; 147 struct timespec ts; 148 __u8 buffer[CN_PROC_MSG_SIZE]; 149 150 if (atomic_read(&proc_event_num_listeners) < 1) 151 return; 152 153 msg = (struct cn_msg *)buffer; 154 ev = (struct proc_event *)msg->data; 155 get_seq(&msg->seq, &ev->cpu); 156 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 157 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 158 ev->what = PROC_EVENT_SID; 159 ev->event_data.sid.process_pid = task->pid; 160 ev->event_data.sid.process_tgid = task->tgid; 161 162 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 163 msg->ack = 0; /* not used */ 164 msg->len = sizeof(*ev); 165 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 166} 167 168void proc_exit_connector(struct task_struct *task) 169{ 170 struct cn_msg *msg; 171 struct proc_event *ev; 172 __u8 buffer[CN_PROC_MSG_SIZE]; 173 struct timespec ts; 174 175 if (atomic_read(&proc_event_num_listeners) < 1) 176 return; 177 178 msg = (struct cn_msg*)buffer; 179 ev = (struct proc_event*)msg->data; 180 get_seq(&msg->seq, &ev->cpu); 181 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 182 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 183 ev->what = PROC_EVENT_EXIT; 184 ev->event_data.exit.process_pid = task->pid; 185 ev->event_data.exit.process_tgid = task->tgid; 186 ev->event_data.exit.exit_code = task->exit_code; 187 ev->event_data.exit.exit_signal = task->exit_signal; 188 189 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 190 msg->ack = 0; /* not used */ 191 msg->len = sizeof(*ev); 192 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 193} 194 195/* 196 * Send an acknowledgement message to userspace 197 * 198 * Use 0 for success, EFOO otherwise. 199 * Note: this is the negative of conventional kernel error 200 * values because it's not being returned via syscall return 201 * mechanisms. 202 */ 203static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) 204{ 205 struct cn_msg *msg; 206 struct proc_event *ev; 207 __u8 buffer[CN_PROC_MSG_SIZE]; 208 struct timespec ts; 209 210 if (atomic_read(&proc_event_num_listeners) < 1) 211 return; 212 213 msg = (struct cn_msg*)buffer; 214 ev = (struct proc_event*)msg->data; 215 msg->seq = rcvd_seq; 216 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 217 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 218 ev->cpu = -1; 219 ev->what = PROC_EVENT_NONE; 220 ev->event_data.ack.err = err; 221 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 222 msg->ack = rcvd_ack + 1; 223 msg->len = sizeof(*ev); 224 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 225} 226 227/** 228 * cn_proc_mcast_ctl 229 * @data: message sent from userspace via the connector 230 */ 231static void cn_proc_mcast_ctl(struct cn_msg *msg, 232 struct netlink_skb_parms *nsp) 233{ 234 enum proc_cn_mcast_op *mc_op = NULL; 235 int err = 0; 236 237 if (msg->len != sizeof(*mc_op)) 238 return; 239 240 mc_op = (enum proc_cn_mcast_op*)msg->data; 241 switch (*mc_op) { 242 case PROC_CN_MCAST_LISTEN: 243 atomic_inc(&proc_event_num_listeners); 244 break; 245 case PROC_CN_MCAST_IGNORE: 246 atomic_dec(&proc_event_num_listeners); 247 break; 248 default: 249 err = EINVAL; 250 break; 251 } 252 cn_proc_ack(err, msg->seq, msg->ack); 253} 254 255/* 256 * cn_proc_init - initialization entry point 257 * 258 * Adds the connector callback to the connector driver. 259 */ 260static int __init cn_proc_init(void) 261{ 262 int err; 263 264 if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc", 265 &cn_proc_mcast_ctl))) { 266 printk(KERN_WARNING "cn_proc failed to register\n"); 267 return err; 268 } 269 return 0; 270} 271 272module_init(cn_proc_init); 273