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#ifdef __linux__ /* only build on linux */
#include <ruby.h>
#ifdef HAVE_RB_WAIT_FOR_SINGLE_FD
#include <ruby/io.h>
#endif
#include <sys/types.h>
#include <unistd.h>
#include <sys/socket.h>
#include <linux/netlink.h>
#include <linux/connector.h>
#define _LINUX_TIME_H
#include <linux/cn_proc.h>
#include <errno.h>
static VALUE mGod;
static VALUE cNetlinkHandler;
static VALUE cEventHandler;
static ID proc_exit;
static ID proc_fork;
static ID m_call;
static ID m_watching_pid;
static int nl_sock; /* socket for netlink connection */
VALUE
nlh_handle_events()
{
char buff[CONNECTOR_MAX_MSG_SIZE];
struct nlmsghdr *hdr;
struct proc_event *event;
VALUE extra_data;
#ifdef HAVE_RB_WAIT_FOR_SINGLE_FD
int ret;
if((ret = rb_wait_for_single_fd(nl_sock, RB_WAITFD_IN, NULL)) < 0){
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
/* If there were no events detected, return */
if(!(ret & RB_WAITFD_IN)){
return INT2FIX(0);
}
#else
fd_set fds;
FD_ZERO(&fds);
FD_SET(nl_sock, &fds);
if (0 > rb_thread_select(nl_sock + 1, &fds, NULL, NULL, NULL)) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
/* If there were no events detected, return */
if (! FD_ISSET(nl_sock, &fds)) {
return INT2FIX(0);
}
#endif
/* if there are events, make calls */
if (-1 == recv(nl_sock, buff, sizeof(buff), 0)) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
hdr = (struct nlmsghdr *)buff;
if (NLMSG_ERROR == hdr->nlmsg_type) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
} else if (NLMSG_DONE == hdr->nlmsg_type) {
event = (struct proc_event *)((struct cn_msg *)NLMSG_DATA(hdr))->data;
switch(event->what) {
case PROC_EVENT_EXIT:
if (Qnil == rb_funcall(cEventHandler, m_watching_pid, 1, INT2FIX(event->event_data.exit.process_pid))) {
return INT2FIX(0);
}
extra_data = rb_hash_new();
rb_hash_aset(extra_data, ID2SYM(rb_intern("pid")), INT2FIX(event->event_data.exit.process_pid));
rb_hash_aset(extra_data, ID2SYM(rb_intern("exit_code")), INT2FIX(event->event_data.exit.exit_code));
rb_hash_aset(extra_data, ID2SYM(rb_intern("exit_signal")), INT2FIX(event->event_data.exit.exit_signal));
rb_hash_aset(extra_data, ID2SYM(rb_intern("thread_group_id")), INT2FIX(event->event_data.exit.process_tgid));
rb_funcall(cEventHandler, m_call, 3, INT2FIX(event->event_data.exit.process_pid), ID2SYM(proc_exit), extra_data);
return INT2FIX(1);
case PROC_EVENT_FORK:
if (Qnil == rb_funcall(cEventHandler, m_watching_pid, 1, INT2FIX(event->event_data.fork.parent_pid))) {
return INT2FIX(0);
}
extra_data = rb_hash_new();
rb_hash_aset(extra_data, ID2SYM(rb_intern("parent_pid")), INT2FIX(event->event_data.fork.parent_pid));
rb_hash_aset(extra_data, ID2SYM(rb_intern("parent_thread_group_id")), INT2FIX(event->event_data.fork.parent_tgid));
rb_hash_aset(extra_data, ID2SYM(rb_intern("child_pid")), INT2FIX(event->event_data.fork.child_pid));
rb_hash_aset(extra_data, ID2SYM(rb_intern("child_thread_group_id")), INT2FIX(event->event_data.fork.child_tgid));
rb_funcall(cEventHandler, m_call, 3, INT2FIX(event->event_data.fork.parent_pid), ID2SYM(proc_fork), extra_data);
return INT2FIX(1);
default:
break;
}
}
return Qnil;
}
#define NL_MESSAGE_SIZE (sizeof(struct nlmsghdr) + sizeof(struct cn_msg) + \
sizeof(int))
void
connect_to_netlink()
{
struct sockaddr_nl sa_nl; /* netlink interface info */
char buff[NL_MESSAGE_SIZE];
struct nlmsghdr *hdr; /* for telling netlink what we want */
struct cn_msg *msg; /* the actual connector message */
/* connect to netlink socket */
nl_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
if (-1 == nl_sock) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
bzero(&sa_nl, sizeof(sa_nl));
sa_nl.nl_family = AF_NETLINK;
sa_nl.nl_groups = CN_IDX_PROC;
sa_nl.nl_pid = getpid();
if (-1 == bind(nl_sock, (struct sockaddr *)&sa_nl, sizeof(sa_nl))) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
/* Fill header */
hdr = (struct nlmsghdr *)buff;
hdr->nlmsg_len = NL_MESSAGE_SIZE;
hdr->nlmsg_type = NLMSG_DONE;
hdr->nlmsg_flags = 0;
hdr->nlmsg_seq = 0;
hdr->nlmsg_pid = getpid();
/* Fill message */
msg = (struct cn_msg *)NLMSG_DATA(hdr);
msg->id.idx = CN_IDX_PROC; /* Connecting to process information */
msg->id.val = CN_VAL_PROC;
msg->seq = 0;
msg->ack = 0;
msg->flags = 0;
msg->len = sizeof(int);
*(int*)msg->data = PROC_CN_MCAST_LISTEN;
if (-1 == send(nl_sock, hdr, hdr->nlmsg_len, 0)) {
rb_raise(rb_eStandardError, "%s", strerror(errno));
}
}
void
Init_netlink_handler_ext()
{
proc_exit = rb_intern("proc_exit");
proc_fork = rb_intern("proc_fork");
m_call = rb_intern("call");
m_watching_pid = rb_intern("watching_pid?");
mGod = rb_const_get(rb_cObject, rb_intern("God"));
cEventHandler = rb_const_get(mGod, rb_intern("EventHandler"));
cNetlinkHandler = rb_define_class_under(mGod, "NetlinkHandler", rb_cObject);
rb_define_singleton_method(cNetlinkHandler, "handle_events", nlh_handle_events, 0);
connect_to_netlink();
}
#endif
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