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 struct appldata_net_sum_data {
30 	u64 timestamp;
31 	u32 sync_count_1;	/* after VM collected the record data, */
32 	u32 sync_count_2;	/* sync_count_1 and sync_count_2 should be the
33 				   same. If not, the record has been updated on
34 				   the Linux side while VM was collecting the
35 				   (possibly corrupt) data */
36 
37 	u32 nr_interfaces;	/* nr. of network interfaces being monitored */
38 
39 	u32 padding;		/* next value is 64-bit aligned, so these */
40 				/* 4 byte would be padded out by compiler */
41 
42 	u64 rx_packets;		/* total packets received        */
43 	u64 tx_packets;		/* total packets transmitted     */
44 	u64 rx_bytes;		/* total bytes received          */
45 	u64 tx_bytes;		/* total bytes transmitted       */
46 	u64 rx_errors;		/* bad packets received          */
47 	u64 tx_errors;		/* packet transmit problems      */
48 	u64 rx_dropped;		/* no space in linux buffers     */
49 	u64 tx_dropped;		/* no space available in linux   */
50 	u64 collisions;		/* collisions while transmitting */
51 } __packed;
52 
53 
54 /*
55  * appldata_get_net_sum_data()
56  *
57  * gather accumulated network statistics
58  */
appldata_get_net_sum_data(void * data)59 static void appldata_get_net_sum_data(void *data)
60 {
61 	int i;
62 	struct appldata_net_sum_data *net_data;
63 	struct net_device *dev;
64 	unsigned long rx_packets, tx_packets, rx_bytes, tx_bytes, rx_errors,
65 			tx_errors, rx_dropped, tx_dropped, collisions;
66 
67 	net_data = data;
68 	net_data->sync_count_1++;
69 
70 	i = 0;
71 	rx_packets = 0;
72 	tx_packets = 0;
73 	rx_bytes   = 0;
74 	tx_bytes   = 0;
75 	rx_errors  = 0;
76 	tx_errors  = 0;
77 	rx_dropped = 0;
78 	tx_dropped = 0;
79 	collisions = 0;
80 
81 	rcu_read_lock();
82 	for_each_netdev_rcu(&init_net, dev) {
83 		const struct rtnl_link_stats64 *stats;
84 		struct rtnl_link_stats64 temp;
85 
86 		stats = dev_get_stats(dev, &temp);
87 		rx_packets += stats->rx_packets;
88 		tx_packets += stats->tx_packets;
89 		rx_bytes   += stats->rx_bytes;
90 		tx_bytes   += stats->tx_bytes;
91 		rx_errors  += stats->rx_errors;
92 		tx_errors  += stats->tx_errors;
93 		rx_dropped += stats->rx_dropped;
94 		tx_dropped += stats->tx_dropped;
95 		collisions += stats->collisions;
96 		i++;
97 	}
98 	rcu_read_unlock();
99 
100 	net_data->nr_interfaces = i;
101 	net_data->rx_packets = rx_packets;
102 	net_data->tx_packets = tx_packets;
103 	net_data->rx_bytes   = rx_bytes;
104 	net_data->tx_bytes   = tx_bytes;
105 	net_data->rx_errors  = rx_errors;
106 	net_data->tx_errors  = tx_errors;
107 	net_data->rx_dropped = rx_dropped;
108 	net_data->tx_dropped = tx_dropped;
109 	net_data->collisions = collisions;
110 
111 	net_data->timestamp = get_tod_clock();
112 	net_data->sync_count_2++;
113 }
114 
115 
116 static struct appldata_ops ops = {
117 	.name	   = "net_sum",
118 	.record_nr = APPLDATA_RECORD_NET_SUM_ID,
119 	.size	   = sizeof(struct appldata_net_sum_data),
120 	.callback  = &appldata_get_net_sum_data,
121 	.owner     = THIS_MODULE,
122 	.mod_lvl   = {0xF0, 0xF0},		/* EBCDIC "00" */
123 };
124 
125 
126 /*
127  * appldata_net_init()
128  *
129  * init data, register ops
130  */
appldata_net_init(void)131 static int __init appldata_net_init(void)
132 {
133 	int ret;
134 
135 	ops.data = kzalloc(sizeof(struct appldata_net_sum_data), GFP_KERNEL);
136 	if (!ops.data)
137 		return -ENOMEM;
138 
139 	ret = appldata_register_ops(&ops);
140 	if (ret)
141 		kfree(ops.data);
142 
143 	return ret;
144 }
145 
146 /*
147  * appldata_net_exit()
148  *
149  * unregister ops
150  */
appldata_net_exit(void)151 static void __exit appldata_net_exit(void)
152 {
153 	appldata_unregister_ops(&ops);
154 	kfree(ops.data);
155 }
156 
157 
158 module_init(appldata_net_init);
159 module_exit(appldata_net_exit);
160 
161 MODULE_LICENSE("GPL");
162 MODULE_AUTHOR("Gerald Schaefer");
163 MODULE_DESCRIPTION("Linux-VM Monitor Stream, accumulated network statistics");
164