From e54c16b1c0c8b1180c5874166de45f61c62385d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anton=20Luka=20=C5=A0ijanec?= <anton@sijanec.eu>
Date: Wed, 21 Aug 2024 15:18:29 +0200
Subject: jedrni modul tcp_times

---
 iv/orodja/ldmitm/tcp_times.c | 117 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 iv/orodja/ldmitm/tcp_times.c

(limited to 'iv/orodja/ldmitm/tcp_times.c')

diff --git a/iv/orodja/ldmitm/tcp_times.c b/iv/orodja/ldmitm/tcp_times.c
new file mode 100644
index 0000000..0996857
--- /dev/null
+++ b/iv/orodja/ldmitm/tcp_times.c
@@ -0,0 +1,117 @@
+/*
+Prevajanje: make
+Namestitev v jedro: insmod tcp_times.ko
+Uporaba v C:
+#include <stdint.h>
+#include "tcp_times.h"
+int tcp_times = open("/proc/tcp_times", O_RDWR);
+if (tcp_times == -1) {
+	perror("open tcp_times");
+	break;
+}
+int tcpsock = accept(boundsocket, &address, &addrlen);
+struct tcp_times tt = {
+	.fd = tcpsock
+};
+if (ioctl(tcp_times, 0, &tt) == -1) {
+	perror("ioctl tcp_times");
+	break;
+}
+// sedaj so polja v tt populirana
+*/
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/proc_fs.h>
+#include <linux/net.h>
+#include <linux/tcp.h>
+#include <linux/version.h>
+#include "tcp_times.h"
+#define MIN(a,b) (((a)<(b))?(a):(b))
+MODULE_AUTHOR("Anton Luka Šijanec <anton@sijanec.eu>");
+MODULE_DESCRIPTION("tcp last received tsval, rtt procfs ioctl driver");
+MODULE_LICENSE("");
+static struct proc_dir_entry * ent;
+static long myioctl (struct file * filep, unsigned int cmd, unsigned long arg) {
+	switch(cmd) {
+		case 0:
+			struct tcp_times tt;
+			if (copy_from_user(&tt, (void *) arg, sizeof tt))
+				return -EFAULT;
+			struct fd f = fdget(tt.fd);
+			if (!f.file)
+				return -EBADF;
+			struct socket * sock = sock_from_file(f.file);
+			if (!sock) {
+				fdput(f);
+				return -ENOTSOCK;
+			}
+			if (!(sock->type & SOCK_STREAM)) {
+				fdput(f);
+				return -ENOSTR;
+			}
+			if (!sock->sk) {
+				fdput(f);
+				return -EBADFD;
+			}
+			if (sock->sk->sk_protocol != IPPROTO_TCP) {
+				fdput(f);
+				return -ESOCKTNOSUPPORT;
+			}
+			struct tcp_sock * tp = tcp_sk(sock->sk);
+			tt.ts_recent_stamp = tp->rx_opt.ts_recent_stamp;
+			tt.ts_recent = tp->rx_opt.ts_recent;
+			tt.rcv_tsval = tp->rx_opt.rcv_tsval;
+			tt.rcv_tsecr = tp->rx_opt.rcv_tsecr;
+			tt.saw_tstamp = tp->rx_opt.saw_tstamp;
+			tt.tstamp_ok = tp->rx_opt.tstamp_ok;
+			tt.dsack = tp->rx_opt.dsack;
+			tt.wscale_ok = tp->rx_opt.wscale_ok;
+			tt.sack_ok = tp->rx_opt.sack_ok;
+			tt.smc_ok = tp->rx_opt.smc_ok;
+			tt.snd_wscale = tp->rx_opt.snd_wscale;
+			tt.rcv_wscale = tp->rx_opt.rcv_wscale;
+			tt.advmss = tp->advmss;
+			tt.rttvar_us = tp->rttvar_us;
+			tt.srtt_us = tp->srtt_us;
+			tt.rcv_rtt_est.rtt_us = tp->rcv_rtt_est.rtt_us;
+			tt.rcv_rtt_est.seq = tp->rcv_rtt_est.seq;
+			tt.rcv_rtt_est.time = tp->rcv_rtt_est.time;
+			tt.rtt_us = tp->rack.rtt_us;
+			tt.mdev_max_us = tp->mdev_max_us;
+			fdput(f);
+			if (copy_to_user((void *) arg, &tt, sizeof tt)) {
+				fdput(f);
+				return -EFAULT;
+			}
+			return 0;
+		default:
+			return -EINVAL;
+	}
+}
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5,6,0)
+static const struct file_operations ops = {
+	.owner = THIS_MODULE,
+	.unlocked_ioctl = myioctl,
+};
+#else
+static const struct proc_ops ops = {
+	.proc_ioctl = myioctl,
+};
+#endif
+static int __init custom_init (void) {
+	ent = proc_create("tcp_times", 0666, NULL, &ops);
+	if (!ent) {
+		printk(KERN_INFO "tcp_times failed to create procfs entry.");
+		return -EINVAL;
+	}
+	printk(KERN_INFO "tcp_times kernel module loaded.");
+	return 0;
+}
+static void __exit custom_exit (void) {
+	proc_remove(ent);
+	printk(KERN_INFO "tcp_times kernel module exiting ...");
+}
+module_init(custom_init);
+module_exit(custom_exit);
-- 
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