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 const struct cred *cred; 110 111 if (atomic_read(&proc_event_num_listeners) < 1) 112 return; 113 114 msg = (struct cn_msg*)buffer; 115 ev = (struct proc_event*)msg->data; 116 ev->what = which_id; 117 ev->event_data.id.process_pid = task->pid; 118 ev->event_data.id.process_tgid = task->tgid; 119 rcu_read_lock(); 120 cred = __task_cred(task); 121 if (which_id == PROC_EVENT_UID) { 122 ev->event_data.id.r.ruid = cred->uid; 123 ev->event_data.id.e.euid = cred->euid; 124 } else if (which_id == PROC_EVENT_GID) { 125 ev->event_data.id.r.rgid = cred->gid; 126 ev->event_data.id.e.egid = cred->egid; 127 } else { 128 rcu_read_unlock(); 129 return; 130 } 131 rcu_read_unlock(); 132 get_seq(&msg->seq, &ev->cpu); 133 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 134 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 135 136 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 137 msg->ack = 0; /* not used */ 138 msg->len = sizeof(*ev); 139 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 140 } 141 142 void proc_exit_connector(struct task_struct *task) 143 { 144 struct cn_msg *msg; 145 struct proc_event *ev; 146 __u8 buffer[CN_PROC_MSG_SIZE]; 147 struct timespec ts; 148 149 if (atomic_read(&proc_event_num_listeners) < 1) 150 return; 151 152 msg = (struct cn_msg*)buffer; 153 ev = (struct proc_event*)msg->data; 154 get_seq(&msg->seq, &ev->cpu); 155 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 156 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 157 ev->what = PROC_EVENT_EXIT; 158 ev->event_data.exit.process_pid = task->pid; 159 ev->event_data.exit.process_tgid = task->tgid; 160 ev->event_data.exit.exit_code = task->exit_code; 161 ev->event_data.exit.exit_signal = task->exit_signal; 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 /* 170 * Send an acknowledgement message to userspace 171 * 172 * Use 0 for success, EFOO otherwise. 173 * Note: this is the negative of conventional kernel error 174 * values because it's not being returned via syscall return 175 * mechanisms. 176 */ 177 static void cn_proc_ack(int err, int rcvd_seq, int rcvd_ack) 178 { 179 struct cn_msg *msg; 180 struct proc_event *ev; 181 __u8 buffer[CN_PROC_MSG_SIZE]; 182 struct timespec ts; 183 184 if (atomic_read(&proc_event_num_listeners) < 1) 185 return; 186 187 msg = (struct cn_msg*)buffer; 188 ev = (struct proc_event*)msg->data; 189 msg->seq = rcvd_seq; 190 ktime_get_ts(&ts); /* get high res monotonic timestamp */ 191 put_unaligned(timespec_to_ns(&ts), (__u64 *)&ev->timestamp_ns); 192 ev->cpu = -1; 193 ev->what = PROC_EVENT_NONE; 194 ev->event_data.ack.err = err; 195 memcpy(&msg->id, &cn_proc_event_id, sizeof(msg->id)); 196 msg->ack = rcvd_ack + 1; 197 msg->len = sizeof(*ev); 198 cn_netlink_send(msg, CN_IDX_PROC, GFP_KERNEL); 199 } 200 201 /** 202 * cn_proc_mcast_ctl 203 * @data: message sent from userspace via the connector 204 */ 205 static void cn_proc_mcast_ctl(struct cn_msg *msg) 206 { 207 enum proc_cn_mcast_op *mc_op = NULL; 208 int err = 0; 209 210 if (msg->len != sizeof(*mc_op)) 211 return; 212 213 mc_op = (enum proc_cn_mcast_op*)msg->data; 214 switch (*mc_op) { 215 case PROC_CN_MCAST_LISTEN: 216 atomic_inc(&proc_event_num_listeners); 217 break; 218 case PROC_CN_MCAST_IGNORE: 219 atomic_dec(&proc_event_num_listeners); 220 break; 221 default: 222 err = EINVAL; 223 break; 224 } 225 cn_proc_ack(err, msg->seq, msg->ack); 226 } 227 228 /* 229 * cn_proc_init - initialization entry point 230 * 231 * Adds the connector callback to the connector driver. 232 */ 233 static int __init cn_proc_init(void) 234 { 235 int err; 236 237 if ((err = cn_add_callback(&cn_proc_event_id, "cn_proc", 238 &cn_proc_mcast_ctl))) { 239 printk(KERN_WARNING "cn_proc failed to register\n"); 240 return err; 241 } 242 return 0; 243 } 244 245 module_init(cn_proc_init); 246