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 38 static atomic_t proc_event_num_listeners = ATOMIC_INIT(0); 39 static 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 */ 42 static DEFINE_PER_CPU(__u32, proc_event_counts) = { 0 }; 43 44 static inline void get_seq(__u32 *ts, int *cpu) 45 { 46 preempt_disable(); 47 *ts = __this_cpu_inc_return(proc_event_counts) -1; 48 *cpu = smp_processor_id(); 49 preempt_enable(); 50 } 51 52 void proc_fork_connector(struct task_struct *task) 53 { 54 struct cn_msg *msg; 55 struct proc_event *ev; 56 __u8 buffer[CN_PROC_MSG_SIZE]; 57 struct timespec ts; 58 59 if (atomic_read(&proc_event_num_listeners) < 1) 60 return; 61 62 msg = (struct cn_msg*)buffer; 63 ev = (struct proc_event*)msg->data; 64 get_seq(&msg->seq, &ev->cpu); 65 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 66 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 67 ev->what = PROC_EVENT_FORK; 68 ev->event_data.fork.parent_pid = task->real_parent->pid; 69 ev->event_data.fork.parent_tgid = task->real_parent->tgid; 70 ev->event_data.fork.child_pid = task->pid; 71 ev->event_data.fork.child_tgid = task->tgid; 72 73 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 74 msg->ack = 0; /* not used */ 75 msg->len = sizeof(*ev); 76 /* If cn_netlink_send() failed, the data is not sent */ 77 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 78 } 79 80 void proc_exec_connector(struct task_struct *task) 81 { 82 struct cn_msg *msg; 83 struct proc_event *ev; 84 struct timespec ts; 85 __u8 buffer[CN_PROC_MSG_SIZE]; 86 87 if (atomic_read(&proc_event_num_listeners) < 1) 88 return; 89 90 msg = (struct cn_msg*)buffer; 91 ev = (struct proc_event*)msg->data; 92 get_seq(&msg->seq, &ev->cpu); 93 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 94 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 95 ev->what = PROC_EVENT_EXEC; 96 ev->event_data.exec.process_pid = task->pid; 97 ev->event_data.exec.process_tgid = task->tgid; 98 99 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 100 msg->ack = 0; /* not used */ 101 msg->len = sizeof(*ev); 102 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 103 } 104 105 void proc_id_connector(struct task_struct *task, int which_id) 106 { 107 struct cn_msg *msg; 108 struct proc_event *ev; 109 __u8 buffer[CN_PROC_MSG_SIZE]; 110 struct timespec ts; 111 const struct cred *cred; 112 113 if (atomic_read(&proc_event_num_listeners) < 1) 114 return; 115 116 msg = (struct cn_msg*)buffer; 117 ev = (struct proc_event*)msg->data; 118 ev->what = which_id; 119 ev->event_data.id.process_pid = task->pid; 120 ev->event_data.id.process_tgid = task->tgid; 121 rcu_read_lock(); 122 cred = __task_cred(task); 123 if (which_id == PROC_EVENT_UID) { 124 ev->event_data.id.r.ruid = cred->uid; 125 ev->event_data.id.e.euid = cred->euid; 126 } else if (which_id == PROC_EVENT_GID) { 127 ev->event_data.id.r.rgid = cred->gid; 128 ev->event_data.id.e.egid = cred->egid; 129 } else { 130 rcu_read_unlock(); 131 return; 132 } 133 rcu_read_unlock(); 134 get_seq(&msg->seq, &ev->cpu); 135 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 136 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 137 138 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 139 msg->ack = 0; /* not used */ 140 msg->len = sizeof(*ev); 141 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 142 } 143 144 void proc_sid_connector(struct task_struct *task) 145 { 146 struct cn_msg *msg; 147 struct proc_event *ev; 148 struct timespec ts; 149 __u8 buffer[CN_PROC_MSG_SIZE]; 150 151 if (atomic_read(&proc_event_num_listeners) < 1) 152 return; 153 154 msg = (struct cn_msg *)buffer; 155 ev = (struct proc_event *)msg->data; 156 get_seq(&msg->seq, &ev->cpu); 157 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 158 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 159 ev->what = PROC_EVENT_SID; 160 ev->event_data.sid.process_pid = task->pid; 161 ev->event_data.sid.process_tgid = task->tgid; 162 163 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 164 msg->ack = 0; /* not used */ 165 msg->len = sizeof(*ev); 166 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 167 } 168 169 void proc_exit_connector(struct task_struct *task) 170 { 171 struct cn_msg *msg; 172 struct proc_event *ev; 173 __u8 buffer[CN_PROC_MSG_SIZE]; 174 struct timespec ts; 175 176 if (atomic_read(&proc_event_num_listeners) < 1) 177 return; 178 179 msg = (struct cn_msg*)buffer; 180 ev = (struct proc_event*)msg->data; 181 get_seq(&msg->seq, &ev->cpu); 182 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 183 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 184 ev->what = PROC_EVENT_EXIT; 185 ev->event_data.exit.process_pid = task->pid; 186 ev->event_data.exit.process_tgid = task->tgid; 187 ev->event_data.exit.exit_code = task->exit_code; 188 ev->event_data.exit.exit_signal = task->exit_signal; 189 190 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 191 msg->ack = 0; /* not used */ 192 msg->len = sizeof(*ev); 193 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 194 } 195 196 /* 197 * Send an acknowledgement message to userspace 198 * 199 * Use 0 for success, EFOO otherwise. 200 * Note: this is the negative of conventional kernel error 201 * values because it's not being returned via syscall return 202 * mechanisms. 203 */ 204 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) 205 { 206 struct cn_msg *msg; 207 struct proc_event *ev; 208 __u8 buffer[CN_PROC_MSG_SIZE]; 209 struct timespec ts; 210 211 if (atomic_read(&proc_event_num_listeners) < 1) 212 return; 213 214 msg = (struct cn_msg*)buffer; 215 ev = (struct proc_event*)msg->data; 216 msg->seq = rcvd_seq; 217 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 218 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 219 ev->cpu = -1; 220 ev->what = PROC_EVENT_NONE; 221 ev->event_data.ack.err = err; 222 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 223 msg->ack = rcvd_ack + 1; 224 msg->len = sizeof(*ev); 225 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 226 } 227 228 /** 229 * cn_proc_mcast_ctl 230 * @data: message sent from userspace via the connector 231 */ 232 static void cn_proc_mcast_ctl(struct cn_msg *msg, 233 struct netlink_skb_parms *nsp) 234 { 235 enum proc_cn_mcast_op *mc_op = NULL; 236 int err = 0; 237 238 if (msg->len != sizeof(*mc_op)) 239 return; 240 241 mc_op = (enum proc_cn_mcast_op*)msg->data; 242 switch (*mc_op) { 243 case PROC_CN_MCAST_LISTEN: 244 atomic_inc(&proc_event_num_listeners); 245 break; 246 case PROC_CN_MCAST_IGNORE: 247 atomic_dec(&proc_event_num_listeners); 248 break; 249 default: 250 err = EINVAL; 251 break; 252 } 253 cn_proc_ack(err, msg->seq, msg->ack); 254 } 255 256 /* 257 * cn_proc_init - initialization entry point 258 * 259 * Adds the connector callback to the connector driver. 260 */ 261 static int __init cn_proc_init(void) 262 { 263 int err; 264 265 if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc", 266 &cn_proc_mcast_ctl))) { 267 printk(KERN_WARNING "cn_proc failed to register\n"); 268 return err; 269 } 270 return 0; 271 } 272 273 module_init(cn_proc_init); 274