ltt-modules/ltt-control.c

   1 /* ltt-control.c
   2  *
   3  * LTT control module over a netlink socket.
   4  *
   5  * Inspired from Relay Apps, by Tom Zanussi and iptables
   6  *
   7  * Copyright 2005 -
   8  * Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
   9  */
  10
  11 #include <linux/init.h>
  12 #include <linux/module.h>
  13 #include <linux/ltt-core.h>
  14 #include <linux/netlink.h>
  15 #include <linux/inet.h>
  16 #include <linux/ip.h>
  17 #include <linux/security.h>
  18 #include <linux/skbuff.h>
  19 #include <linux/types.h>
  20 #include <net/sock.h>
  21 #include "ltt-control.h"
  22
  23
  24 #define LTTCTLM_BASE    0x10
  25 #define LTTCTLM_CONTROL (LTTCTLM_BASE + 1)      /* LTT control message */
  26
  27 static struct sock *socket;
  28
  29 void ltt_control_input(struct sock *sk, int len)
  30 {
  31         struct sk_buff *skb;
  32         struct nlmsghdr *nlh = NULL;
  33         u8 *payload = NULL;
  34         lttctl_peer_msg_t *msg;
  35         int err;
  36
  37         printk(KERN_ALERT "ltt-control ltt_control_input\n");
  38
  39         while ((skb = skb_dequeue(&sk->sk_receive_queue))
  40                                         != NULL) {
  41
  42                 nlh = (struct nlmsghdr *)skb->data;
  43
  44     if(security_netlink_recv(skb)) {
  45                         netlink_ack(skb, nlh, EPERM);
  46                         kfree_skb(skb);
  47                         continue;
  48     }
  49
  50                 /* process netlink message pointed by skb->data */
  51                 err = EINVAL;
  52                 payload = NLMSG_DATA(nlh);
  53                 /* process netlink message with header pointed by
  54                  * nlh and payload pointed by payload
  55                  */
  56                 if(nlh->nlmsg_len != sizeof(lttctl_peer_msg_t) + sizeof(struct nlmsghdr)) {
  57                         printk(KERN_ALERT "ltt-control bad message length\n");
  58                         netlink_ack(skb, nlh, EINVAL);
  59                         kfree_skb(skb);
  60                         continue;
  61                 }
  62                 msg = (lttctl_peer_msg_t*)payload;
  63
  64                 switch(msg->op) {
  65                         case OP_CREATE:
  66                                 err = ltt_control(LTT_CONTROL_CREATE_TRACE, msg->trace_name,
  67                                                                                                                         msg->args);
  68                                 break;
  69                         case OP_DESTROY:
  70                                 err = ltt_control(LTT_CONTROL_DESTROY_TRACE, msg->trace_name,
  71                                                 msg->args);
  72                                 break;
  73                         case OP_START:
  74                                 err = ltt_control(LTT_CONTROL_START, msg->trace_name,
  75                                                 msg->args);
  76                                 break;
  77                         case OP_STOP:
  78                                 err = ltt_control(LTT_CONTROL_STOP, msg->trace_name,
  79                                                 msg->args);
  80                                 break;
  81                         default:
  82                                 err = EBADRQC;
  83                                 printk(KERN_INFO "ltt-control invalid operation\n");
  84                 }
  85                 netlink_ack(skb, nlh, err);
  86                 kfree_skb(skb);
  87         }
  88 }
  89
  90
  91 static int ltt_control_init(void)
  92 {
  93         printk(KERN_ALERT "ltt-control init\n");
  94
  95         socket = netlink_kernel_create(NETLINK_LTT, 1,
  96                         ltt_control_input, THIS_MODULE);
  97         if(socket == NULL) return -EPERM;
  98         else return 0;
  99 }
 100
 101 static void ltt_control_exit(void)
 102 {
 103         printk(KERN_ALERT "ltt-control exit\n");
 104
 105         sock_release(socket->sk_socket);
 106 }
 107
 108
 109 module_init(ltt_control_init)
 110 module_exit(ltt_control_exit)
 111
 112 MODULE_LICENSE("GPL");
 113 MODULE_AUTHOR("Mathieu Desnoyers");
 114 MODULE_DESCRIPTION("Linux Trace Toolkit Controller");
 115