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Watch process creation.
/* exec-notify, so you can watch your acrobat reader or vim executing "bash -c"
* commands ;-)
* Requires some 2.6.x Linux kernel with proc connector enabled.
*
* $ cc -Wall -ansi -pedantic -std=c99 exec-notify.c
*
* (C) 2007-2010 Sebastian Krahmer <krahmer@suse.de> original netlink handling
* stolen from an proc-connector example, copyright folows:
*/
/*
*
* Copyright (C) Matt Helsley, IBM Corp. 2005
* Derived from fcctl.c by Guillaume Thouvenin
* Original copyright notice follows:
*
* Copyright (C) 2005 BULL SA.
* Written by Guillaume Thouvenin <guillaume.thouvenin@bull.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <linux/connector.h>
#include <linux/netlink.h>
#include <linux/cn_proc.h>
#define SEND_MESSAGE_LEN (NLMSG_LENGTH(sizeof(struct cn_msg) + \
sizeof(enum proc_cn_mcast_op)))
#define RECV_MESSAGE_LEN (NLMSG_LENGTH(sizeof(struct cn_msg) + \
sizeof(struct proc_event)))
#define SEND_MESSAGE_SIZE (NLMSG_SPACE(SEND_MESSAGE_LEN))
#define RECV_MESSAGE_SIZE (NLMSG_SPACE(RECV_MESSAGE_LEN))
#define max(x,y) ((y)<(x)?(x):(y))
#define min(x,y) ((y)>(x)?(x):(y))
#define BUFF_SIZE (max(max(SEND_MESSAGE_SIZE, RECV_MESSAGE_SIZE), 1024))
#define MIN_RECV_SIZE (min(SEND_MESSAGE_SIZE, RECV_MESSAGE_SIZE))
#define PROC_CN_MCAST_LISTEN (1)
#define PROC_CN_MCAST_IGNORE (2)
void handle_msg (struct cn_msg *cn_hdr)
{
char cmdline[1024], fname1[1024], ids[1024], fname2[1024], buf[1024];
int r = 0, fd, i;
FILE *f = NULL;
struct proc_event *ev = (struct proc_event *)cn_hdr->data;
snprintf(fname1, sizeof(fname1), "/proc/%d/status", ev->event_data.exec.process_pid);
snprintf(fname2, sizeof(fname2), "/proc/%d/cmdline", ev->event_data.exec.process_pid);
f = fopen(fname1, "r");
fd = open(fname2, O_RDONLY);
memset(&cmdline, 0, sizeof(cmdline));
memset(&ids, 0, sizeof(ids));
while (f && fgets(buf, sizeof(buf), f) != NULL) {
if (strstr(buf, "Uid")) {
strtok(buf, "\n");
snprintf(ids, sizeof(ids), "%s", buf);
}
}
if (f)
fclose(f);
if (fd > 0) {
r = read(fd, cmdline, sizeof(cmdline));
close(fd);
for (i = 0; r > 0 && i < r; ++i) {
if (cmdline[i] == 0)
cmdline[i] = ' ';
}
}
switch(ev->what){
case PROC_EVENT_FORK:
printf("FORK:parent(pid,tgid)=%d,%d\tchild(pid,tgid)=%d,%d\t[%s]\n",
ev->event_data.fork.parent_pid,
ev->event_data.fork.parent_tgid,
ev->event_data.fork.child_pid,
ev->event_data.fork.child_tgid, cmdline);
break;
case PROC_EVENT_EXEC:
printf("EXEC:pid=%d,tgid=%d\t[%s]\t[%s]\n",
ev->event_data.exec.process_pid,
ev->event_data.exec.process_tgid, ids, cmdline);
break;
case PROC_EVENT_EXIT:
printf("EXIT:pid=%d,%d\texit code=%d\n",
ev->event_data.exit.process_pid,
ev->event_data.exit.process_tgid,
ev->event_data.exit.exit_code);
break;
case PROC_EVENT_UID:
printf("UID:pid=%d,%d ruid=%d,euid=%d\n",
ev->event_data.id.process_pid, ev->event_data.id.process_tgid,
ev->event_data.id.r.ruid, ev->event_data.id.e.euid);
break;
default:
break;
}
}
int main(int argc, char **argv)
{
int sk_nl;
int err;
struct sockaddr_nl my_nla, kern_nla, from_nla;
socklen_t from_nla_len;
char buff[BUFF_SIZE];
int rc = -1;
struct nlmsghdr *nl_hdr;
struct cn_msg *cn_hdr;
enum proc_cn_mcast_op *mcop_msg;
size_t recv_len = 0;
if (getuid() != 0) {
printf("Only root can start/stop the fork connector\n");
return 0;
}
if (argc != 1)
return 0;
setvbuf(stdout, NULL, _IONBF, 0);
/*
* Create an endpoint for communication. Use the kernel user
* interface device (PF_NETLINK) which is a datagram oriented
* service (SOCK_DGRAM). The protocol used is the connector
* protocol (NETLINK_CONNECTOR)
*/
sk_nl = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_CONNECTOR);
if (sk_nl == -1) {
printf("socket sk_nl error");
return rc;
}
my_nla.nl_family = AF_NETLINK;
my_nla.nl_groups = CN_IDX_PROC;
my_nla.nl_pid = getpid();
kern_nla.nl_family = AF_NETLINK;
kern_nla.nl_groups = CN_IDX_PROC;
kern_nla.nl_pid = 1;
err = bind(sk_nl, (struct sockaddr *)&my_nla, sizeof(my_nla));
if (err == -1) {
printf("binding sk_nl error");
goto close_and_exit;
}
nl_hdr = (struct nlmsghdr *)buff;
cn_hdr = (struct cn_msg *)NLMSG_DATA(nl_hdr);
mcop_msg = (enum proc_cn_mcast_op*)&cn_hdr->data[0];
printf("sending proc connector: PROC_CN_MCAST_LISTEN... ");
memset(buff, 0, sizeof(buff));
*mcop_msg = PROC_CN_MCAST_LISTEN;
/* fill the netlink header */
nl_hdr->nlmsg_len = SEND_MESSAGE_LEN;
nl_hdr->nlmsg_type = NLMSG_DONE;
nl_hdr->nlmsg_flags = 0;
nl_hdr->nlmsg_seq = 0;
nl_hdr->nlmsg_pid = getpid();
/* fill the connector header */
cn_hdr->id.idx = CN_IDX_PROC;
cn_hdr->id.val = CN_VAL_PROC;
cn_hdr->seq = 0;
cn_hdr->ack = 0;
cn_hdr->len = sizeof(enum proc_cn_mcast_op);
if (send(sk_nl, nl_hdr, nl_hdr->nlmsg_len, 0) != nl_hdr->nlmsg_len) {
printf("failed to send proc connector mcast ctl op!\n");
goto close_and_exit;
}
printf("sent\n");
if (*mcop_msg == PROC_CN_MCAST_IGNORE) {
rc = 0;
goto close_and_exit;
}
printf("Reading process events from proc connector.\n"
"Hit Ctrl-C to exit\n");
for(memset(buff, 0, sizeof(buff)), from_nla_len = sizeof(from_nla);
; memset(buff, 0, sizeof(buff)), from_nla_len = sizeof(from_nla)) {
struct nlmsghdr *nlh = (struct nlmsghdr*)buff;
memcpy(&from_nla, &kern_nla, sizeof(from_nla));
recv_len = recvfrom(sk_nl, buff, BUFF_SIZE, 0,
(struct sockaddr*)&from_nla, &from_nla_len);
if (from_nla.nl_pid != 0)
continue;
if (recv_len < 1)
continue;
while (NLMSG_OK(nlh, recv_len)) {
cn_hdr = NLMSG_DATA(nlh);
if (nlh->nlmsg_type == NLMSG_NOOP)
continue;
if ((nlh->nlmsg_type == NLMSG_ERROR) ||
(nlh->nlmsg_type == NLMSG_OVERRUN))
break;
handle_msg(cn_hdr);
if (nlh->nlmsg_type == NLMSG_DONE)
break;
nlh = NLMSG_NEXT(nlh, recv_len);
}
}
close_and_exit:
close(sk_nl);
exit(rc);
return 0;
}
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