1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Data gathering module for Linux-VM Monitor Stream, Stage 1.
4  * Collects accumulated network statistics (Packets received/transmitted,
5  * dropped, errors, ...).
6  *
7  * Copyright IBM Corp. 2003, 2006
8  *
9  * Author: Gerald Schaefer <gerald.schaefer@de.ibm.com>
10  */
11 
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/errno.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/netdevice.h>
17 #include <net/net_namespace.h>
18 
19 #include "appldata.h"
20 
21 
22 /*
23  * Network data
24  *
25  * This is accessed as binary data by z/VM. If changes to it can't be avoided,
26  * the structure version (product ID, see appldata_base.c) needs to be changed
27  * as well and all documentation and z/VM applications using it must be updated.
28  *
29  * The record layout is documented in the Linux for zSeries Device Drivers
30  * book:
31  * http://oss.software.ibm.com/developerworks/opensource/linux390/index.shtml
32  */
33 struct appldata_net_sum_data {
34 	u64 timestamp;
35 	u32 sync_count_1;	/* after VM collected the record data, */
36 	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
37 				   same. If not, the record has been updated on
38 				   the Linux side while VM was collecting the
39 				   (possibly corrupt) data */
40 
41 	u32 nr_interfaces;	/* nr. of network interfaces being monitored */
42 
43 	u32 padding;		/* next value is 64-bit aligned, so these */
44 				/* 4 byte would be padded out by compiler */
45 
46 	u64 rx_packets;		/* total packets received        */
47 	u64 tx_packets;		/* total packets transmitted     */
48 	u64 rx_bytes;		/* total bytes received          */
49 	u64 tx_bytes;		/* total bytes transmitted       */
50 	u64 rx_errors;		/* bad packets received          */
51 	u64 tx_errors;		/* packet transmit problems      */
52 	u64 rx_dropped;		/* no space in linux buffers     */
53 	u64 tx_dropped;		/* no space available in linux   */
54 	u64 collisions;		/* collisions while transmitting */
55 } __packed;
56 
57 
58 /*
59  * appldata_get_net_sum_data()
60  *
61  * gather accumulated network statistics
62  */
63 static void appldata_get_net_sum_data(void *data)
64 {
65 	int i;
66 	struct appldata_net_sum_data *net_data;
67 	struct net_device *dev;
68 	unsigned long rx_packets, tx_packets, rx_bytes, tx_bytes, rx_errors,
69 			tx_errors, rx_dropped, tx_dropped, collisions;
70 
71 	net_data = data;
72 	net_data->sync_count_1++;
73 
74 	i = 0;
75 	rx_packets = 0;
76 	tx_packets = 0;
77 	rx_bytes   = 0;
78 	tx_bytes   = 0;
79 	rx_errors  = 0;
80 	tx_errors  = 0;
81 	rx_dropped = 0;
82 	tx_dropped = 0;
83 	collisions = 0;
84 
85 	rcu_read_lock();
86 	for_each_netdev_rcu(&init_net, dev) {
87 		const struct rtnl_link_stats64 *stats;
88 		struct rtnl_link_stats64 temp;
89 
90 		stats = dev_get_stats(dev, &temp);
91 		rx_packets += stats->rx_packets;
92 		tx_packets += stats->tx_packets;
93 		rx_bytes   += stats->rx_bytes;
94 		tx_bytes   += stats->tx_bytes;
95 		rx_errors  += stats->rx_errors;
96 		tx_errors  += stats->tx_errors;
97 		rx_dropped += stats->rx_dropped;
98 		tx_dropped += stats->tx_dropped;
99 		collisions += stats->collisions;
100 		i++;
101 	}
102 	rcu_read_unlock();
103 
104 	net_data->nr_interfaces = i;
105 	net_data->rx_packets = rx_packets;
106 	net_data->tx_packets = tx_packets;
107 	net_data->rx_bytes   = rx_bytes;
108 	net_data->tx_bytes   = tx_bytes;
109 	net_data->rx_errors  = rx_errors;
110 	net_data->tx_errors  = tx_errors;
111 	net_data->rx_dropped = rx_dropped;
112 	net_data->tx_dropped = tx_dropped;
113 	net_data->collisions = collisions;
114 
115 	net_data->timestamp = get_tod_clock();
116 	net_data->sync_count_2++;
117 }
118 
119 
120 static struct appldata_ops ops = {
121 	.name	   = "net_sum",
122 	.record_nr = APPLDATA_RECORD_NET_SUM_ID,
123 	.size	   = sizeof(struct appldata_net_sum_data),
124 	.callback  = &appldata_get_net_sum_data,
125 	.owner     = THIS_MODULE,
126 	.mod_lvl   = {0xF0, 0xF0},		/* EBCDIC "00" */
127 };
128 
129 
130 /*
131  * appldata_net_init()
132  *
133  * init data, register ops
134  */
135 static int __init appldata_net_init(void)
136 {
137 	int ret;
138 
139 	ops.data = kzalloc(sizeof(struct appldata_net_sum_data), GFP_KERNEL);
140 	if (!ops.data)
141 		return -ENOMEM;
142 
143 	ret = appldata_register_ops(&ops);
144 	if (ret)
145 		kfree(ops.data);
146 
147 	return ret;
148 }
149 
150 /*
151  * appldata_net_exit()
152  *
153  * unregister ops
154  */
155 static void __exit appldata_net_exit(void)
156 {
157 	appldata_unregister_ops(&ops);
158 	kfree(ops.data);
159 }
160 
161 
162 module_init(appldata_net_init);
163 module_exit(appldata_net_exit);
164 
165 MODULE_LICENSE("GPL");
166 MODULE_AUTHOR("Gerald Schaefer");
167 MODULE_DESCRIPTION("Linux-VM Monitor Stream, accumulated network statistics");
168