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 <linux/ptrace.h> 32 #include <linux/atomic.h> 33 #include <linux/pid_namespace.h> 34 35 #include <asm/unaligned.h> 36 37 #include <linux/cn_proc.h> 38 39 #define CN_PROC_MSG_SIZE (sizeof(struct cn_msg) + sizeof(struct proc_event)) 40 41 static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); 42 static struct cb_id cn_proc_event_id = { CN_IDX_PROC, CN_VAL_PROC }; 43 44 /* proc_event_counts is used as the sequence number of the netlink message */ 45 static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; 46 47 static inline void get_seq(__u32 *ts, int *cpu) 48 { 49 preempt_disable(); 50 *ts = __this_cpu_inc_return(proc_event_counts) - 1; 51 *cpu = smp_processor_id(); 52 preempt_enable(); 53 } 54 55 void proc_fork_connector(struct task_struct *task) 56 { 57 struct cn_msg *msg; 58 struct proc_event *ev; 59 __u8 buffer[CN_PROC_MSG_SIZE]; 60 struct timespec ts; 61 struct task_struct *parent; 62 63 if (atomic_read(&proc_event_num_listeners) < 1) 64 return; 65 66 msg = (struct cn_msg *)buffer; 67 ev = (struct proc_event *)msg->data; 68 memset(&ev->event_data, 0, sizeof(ev->event_data)); 69 get_seq(&msg->seq, &ev->cpu); 70 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 71 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 72 ev->what = PROC_EVENT_FORK; 73 rcu_read_lock(); 74 parent = rcu_dereference(task->real_parent); 75 ev->event_data.fork.parent_pid = parent->pid; 76 ev->event_data.fork.parent_tgid = parent->tgid; 77 rcu_read_unlock(); 78 ev->event_data.fork.child_pid = task->pid; 79 ev->event_data.fork.child_tgid = task->tgid; 80 81 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 82 msg->ack = 0; /* not used */ 83 msg->len = sizeof(*ev); 84 msg->flags = 0; /* not used */ 85 /* If cn_netlink_send() failed, the data is not sent */ 86 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 87 } 88 89 void proc_exec_connector(struct task_struct *task) 90 { 91 struct cn_msg *msg; 92 struct proc_event *ev; 93 struct timespec ts; 94 __u8 buffer[CN_PROC_MSG_SIZE]; 95 96 if (atomic_read(&proc_event_num_listeners) < 1) 97 return; 98 99 msg = (struct cn_msg *)buffer; 100 ev = (struct proc_event *)msg->data; 101 memset(&ev->event_data, 0, sizeof(ev->event_data)); 102 get_seq(&msg->seq, &ev->cpu); 103 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 104 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 105 ev->what = PROC_EVENT_EXEC; 106 ev->event_data.exec.process_pid = task->pid; 107 ev->event_data.exec.process_tgid = task->tgid; 108 109 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 110 msg->ack = 0; /* not used */ 111 msg->len = sizeof(*ev); 112 msg->flags = 0; /* not used */ 113 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 114 } 115 116 void proc_id_connector(struct task_struct *task, int which_id) 117 { 118 struct cn_msg *msg; 119 struct proc_event *ev; 120 __u8 buffer[CN_PROC_MSG_SIZE]; 121 struct timespec ts; 122 const struct cred *cred; 123 124 if (atomic_read(&proc_event_num_listeners) < 1) 125 return; 126 127 msg = (struct cn_msg *)buffer; 128 ev = (struct proc_event *)msg->data; 129 memset(&ev->event_data, 0, sizeof(ev->event_data)); 130 ev->what = which_id; 131 ev->event_data.id.process_pid = task->pid; 132 ev->event_data.id.process_tgid = task->tgid; 133 rcu_read_lock(); 134 cred = __task_cred(task); 135 if (which_id == PROC_EVENT_UID) { 136 ev->event_data.id.r.ruid = from_kuid_munged(&init_user_ns, cred->uid); 137 ev->event_data.id.e.euid = from_kuid_munged(&init_user_ns, cred->euid); 138 } else if (which_id == PROC_EVENT_GID) { 139 ev->event_data.id.r.rgid = from_kgid_munged(&init_user_ns, cred->gid); 140 ev->event_data.id.e.egid = from_kgid_munged(&init_user_ns, cred->egid); 141 } else { 142 rcu_read_unlock(); 143 return; 144 } 145 rcu_read_unlock(); 146 get_seq(&msg->seq, &ev->cpu); 147 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 148 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 149 150 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 151 msg->ack = 0; /* not used */ 152 msg->len = sizeof(*ev); 153 msg->flags = 0; /* not used */ 154 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 155 } 156 157 void proc_sid_connector(struct task_struct *task) 158 { 159 struct cn_msg *msg; 160 struct proc_event *ev; 161 struct timespec ts; 162 __u8 buffer[CN_PROC_MSG_SIZE]; 163 164 if (atomic_read(&proc_event_num_listeners) < 1) 165 return; 166 167 msg = (struct cn_msg *)buffer; 168 ev = (struct proc_event *)msg->data; 169 memset(&ev->event_data, 0, sizeof(ev->event_data)); 170 get_seq(&msg->seq, &ev->cpu); 171 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 172 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 173 ev->what = PROC_EVENT_SID; 174 ev->event_data.sid.process_pid = task->pid; 175 ev->event_data.sid.process_tgid = task->tgid; 176 177 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 178 msg->ack = 0; /* not used */ 179 msg->len = sizeof(*ev); 180 msg->flags = 0; /* not used */ 181 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 182 } 183 184 void proc_ptrace_connector(struct task_struct *task, int ptrace_id) 185 { 186 struct cn_msg *msg; 187 struct proc_event *ev; 188 struct timespec ts; 189 __u8 buffer[CN_PROC_MSG_SIZE]; 190 191 if (atomic_read(&proc_event_num_listeners) < 1) 192 return; 193 194 msg = (struct cn_msg *)buffer; 195 ev = (struct proc_event *)msg->data; 196 memset(&ev->event_data, 0, sizeof(ev->event_data)); 197 get_seq(&msg->seq, &ev->cpu); 198 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 199 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 200 ev->what = PROC_EVENT_PTRACE; 201 ev->event_data.ptrace.process_pid = task->pid; 202 ev->event_data.ptrace.process_tgid = task->tgid; 203 if (ptrace_id == PTRACE_ATTACH) { 204 ev->event_data.ptrace.tracer_pid = current->pid; 205 ev->event_data.ptrace.tracer_tgid = current->tgid; 206 } else if (ptrace_id == PTRACE_DETACH) { 207 ev->event_data.ptrace.tracer_pid = 0; 208 ev->event_data.ptrace.tracer_tgid = 0; 209 } else 210 return; 211 212 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 213 msg->ack = 0; /* not used */ 214 msg->len = sizeof(*ev); 215 msg->flags = 0; /* not used */ 216 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 217 } 218 219 void proc_comm_connector(struct task_struct *task) 220 { 221 struct cn_msg *msg; 222 struct proc_event *ev; 223 struct timespec ts; 224 __u8 buffer[CN_PROC_MSG_SIZE]; 225 226 if (atomic_read(&proc_event_num_listeners) < 1) 227 return; 228 229 msg = (struct cn_msg *)buffer; 230 ev = (struct proc_event *)msg->data; 231 memset(&ev->event_data, 0, sizeof(ev->event_data)); 232 get_seq(&msg->seq, &ev->cpu); 233 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 234 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 235 ev->what = PROC_EVENT_COMM; 236 ev->event_data.comm.process_pid = task->pid; 237 ev->event_data.comm.process_tgid = task->tgid; 238 get_task_comm(ev->event_data.comm.comm, task); 239 240 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 241 msg->ack = 0; /* not used */ 242 msg->len = sizeof(*ev); 243 msg->flags = 0; /* not used */ 244 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 245 } 246 247 void proc_coredump_connector(struct task_struct *task) 248 { 249 struct cn_msg *msg; 250 struct proc_event *ev; 251 __u8 buffer[CN_PROC_MSG_SIZE]; 252 struct timespec ts; 253 254 if (atomic_read(&proc_event_num_listeners) < 1) 255 return; 256 257 msg = (struct cn_msg *)buffer; 258 ev = (struct proc_event *)msg->data; 259 memset(&ev->event_data, 0, sizeof(ev->event_data)); 260 get_seq(&msg->seq, &ev->cpu); 261 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 262 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 263 ev->what = PROC_EVENT_COREDUMP; 264 ev->event_data.coredump.process_pid = task->pid; 265 ev->event_data.coredump.process_tgid = task->tgid; 266 267 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 268 msg->ack = 0; /* not used */ 269 msg->len = sizeof(*ev); 270 msg->flags = 0; /* not used */ 271 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 272 } 273 274 void proc_exit_connector(struct task_struct *task) 275 { 276 struct cn_msg *msg; 277 struct proc_event *ev; 278 __u8 buffer[CN_PROC_MSG_SIZE]; 279 struct timespec ts; 280 281 if (atomic_read(&proc_event_num_listeners) < 1) 282 return; 283 284 msg = (struct cn_msg *)buffer; 285 ev = (struct proc_event *)msg->data; 286 memset(&ev->event_data, 0, sizeof(ev->event_data)); 287 get_seq(&msg->seq, &ev->cpu); 288 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 289 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 290 ev->what = PROC_EVENT_EXIT; 291 ev->event_data.exit.process_pid = task->pid; 292 ev->event_data.exit.process_tgid = task->tgid; 293 ev->event_data.exit.exit_code = task->exit_code; 294 ev->event_data.exit.exit_signal = task->exit_signal; 295 296 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 297 msg->ack = 0; /* not used */ 298 msg->len = sizeof(*ev); 299 msg->flags = 0; /* not used */ 300 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 301 } 302 303 /* 304 * Send an acknowledgement message to userspace 305 * 306 * Use 0 for success, EFOO otherwise. 307 * Note: this is the negative of conventional kernel error 308 * values because it's not being returned via syscall return 309 * mechanisms. 310 */ 311 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) 312 { 313 struct cn_msg *msg; 314 struct proc_event *ev; 315 __u8 buffer[CN_PROC_MSG_SIZE]; 316 struct timespec ts; 317 318 if (atomic_read(&proc_event_num_listeners) < 1) 319 return; 320 321 msg = (struct cn_msg *)buffer; 322 ev = (struct proc_event *)msg->data; 323 memset(&ev->event_data, 0, sizeof(ev->event_data)); 324 msg->seq = rcvd_seq; 325 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 326 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 327 ev->cpu = -1; 328 ev->what = PROC_EVENT_NONE; 329 ev->event_data.ack.err = err; 330 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 331 msg->ack = rcvd_ack + 1; 332 msg->len = sizeof(*ev); 333 msg->flags = 0; /* not used */ 334 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 335 } 336 337 /** 338 * cn_proc_mcast_ctl 339 * @data: message sent from userspace via the connector 340 */ 341 static void cn_proc_mcast_ctl(struct cn_msg *msg, 342 struct netlink_skb_parms *nsp) 343 { 344 enum proc_cn_mcast_op *mc_op = NULL; 345 int err = 0; 346 347 if (msg->len != sizeof(*mc_op)) 348 return; 349 350 /* 351 * Events are reported with respect to the initial pid 352 * and user namespaces so ignore requestors from 353 * other namespaces. 354 */ 355 if ((current_user_ns() != &init_user_ns) || 356 (task_active_pid_ns(current) != &init_pid_ns)) 357 return; 358 359 /* Can only change if privileged. */ 360 if (!capable(CAP_NET_ADMIN)) { 361 err = EPERM; 362 goto out; 363 } 364 365 mc_op = (enum proc_cn_mcast_op *)msg->data; 366 switch (*mc_op) { 367 case PROC_CN_MCAST_LISTEN: 368 atomic_inc(&proc_event_num_listeners); 369 break; 370 case PROC_CN_MCAST_IGNORE: 371 atomic_dec(&proc_event_num_listeners); 372 break; 373 default: 374 err = EINVAL; 375 break; 376 } 377 378 out: 379 cn_proc_ack(err, msg->seq, msg->ack); 380 } 381 382 /* 383 * cn_proc_init - initialization entry point 384 * 385 * Adds the connector callback to the connector driver. 386 */ 387 static int __init cn_proc_init(void) 388 { 389 int err = cn_add_callback(&cn_proc_event_id, 390 "cn_proc", 391 &cn_proc_mcast_ctl); 392 if (err) { 393 pr_warn("cn_proc failed to register\n"); 394 return err; 395 } 396 return 0; 397 } 398 399 module_init(cn_proc_init); 400