Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * INET		An implementation of the TCP/IP protocol suite for the LINUX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *		operating system.  INET is implemented using the  BSD Socket
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *		interface as the means of communication with the user level.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *		Pseudo-driver for the loopback interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * Version:	@(#)loopback.c	1.0.4b	08/16/93
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  * Authors:	Ross Biro
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  *		Donald Becker, <becker@scyld.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15)  *		Alan Cox	:	Fixed oddments for NET3.014
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16)  *		Alan Cox	:	Rejig for NET3.029 snap #3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17)  *		Alan Cox	:	Fixed NET3.029 bugs and sped up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18)  *		Larry McVoy	:	Tiny tweak to double performance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19)  *		Alan Cox	:	Backed out LMV's tweak - the linux mm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20)  *					can't take it...
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21)  *              Michael Griffith:       Don't bother computing the checksums
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  *                                      on packets received on the loopback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  *                                      interface.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  *		Alexey Kuznetsov:	Potential hang under some extreme
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  *					cases removed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <linux/jiffies.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) #include <linux/interrupt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) #include <linux/string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) #include <linux/socket.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) #include <linux/errno.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) #include <linux/fcntl.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) #include <linux/in.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) #include <linux/inet.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) #include <linux/netdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) #include <linux/etherdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) #include <linux/ethtool.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) #include <net/sock.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) #include <net/checksum.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) #include <linux/if_ether.h>	/* For the statistics structure. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) #include <linux/if_arp.h>	/* For ARPHRD_ETHER */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) #include <linux/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) #include <linux/tcp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) #include <linux/percpu.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) #include <linux/net_tstamp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) #include <net/net_namespace.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) #include <linux/u64_stats_sync.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) /* blackhole_netdev - a device used for dsts that are marked expired!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59)  * This is global device (instead of per-net-ns) since it's not needed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60)  * to be per-ns and gets initialized at boot time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) struct net_device *blackhole_netdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) EXPORT_SYMBOL(blackhole_netdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) /* The higher levels take care of making this non-reentrant (it's
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66)  * called with bh's disabled).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) static netdev_tx_t loopback_xmit(struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 				 struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	skb_tx_timestamp(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 	/* do not fool net_timestamp_check() with various clock bases */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	skb->tstamp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	skb_orphan(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	/* Before queueing this packet to netif_rx(),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	 * make sure dst is refcounted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	skb_dst_force(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	skb->protocol = eth_type_trans(skb, dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	len = skb->len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	if (likely(netif_rx(skb) == NET_RX_SUCCESS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 		dev_lstats_add(dev, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	return NETDEV_TX_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	*packets = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 	*bytes = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	for_each_possible_cpu(i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 		const struct pcpu_lstats *lb_stats;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 		u64 tbytes, tpackets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		unsigned int start;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		lb_stats = per_cpu_ptr(dev->lstats, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 		do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 			start = u64_stats_fetch_begin_irq(&lb_stats->syncp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 			tpackets = u64_stats_read(&lb_stats->packets);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 			tbytes = u64_stats_read(&lb_stats->bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		} while (u64_stats_fetch_retry_irq(&lb_stats->syncp, start));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 		*bytes   += tbytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 		*packets += tpackets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) EXPORT_SYMBOL(dev_lstats_read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) static void loopback_get_stats64(struct net_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 				 struct rtnl_link_stats64 *stats)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 	u64 packets, bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 	dev_lstats_read(dev, &packets, &bytes);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	stats->rx_packets = packets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	stats->tx_packets = packets;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	stats->rx_bytes   = bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	stats->tx_bytes   = bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static u32 always_on(struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 	return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) static const struct ethtool_ops loopback_ethtool_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	.get_link		= always_on,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	.get_ts_info		= ethtool_op_get_ts_info,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) static int loopback_dev_init(struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 	dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	if (!dev->lstats)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) static void loopback_dev_free(struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	dev_net(dev)->loopback_dev = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 	free_percpu(dev->lstats);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) static const struct net_device_ops loopback_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	.ndo_init        = loopback_dev_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 	.ndo_start_xmit  = loopback_xmit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	.ndo_get_stats64 = loopback_get_stats64,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	.ndo_set_mac_address = eth_mac_addr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) static void gen_lo_setup(struct net_device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 			 unsigned int mtu,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 			 const struct ethtool_ops *eth_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 			 const struct header_ops *hdr_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 			 const struct net_device_ops *dev_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 			 void (*dev_destructor)(struct net_device *dev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 	dev->mtu		= mtu;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	dev->hard_header_len	= ETH_HLEN;	/* 14	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	dev->min_header_len	= ETH_HLEN;	/* 14	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 	dev->addr_len		= ETH_ALEN;	/* 6	*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	dev->type		= ARPHRD_LOOPBACK;	/* 0x0001*/
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	dev->flags		= IFF_LOOPBACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	dev->priv_flags		|= IFF_LIVE_ADDR_CHANGE | IFF_NO_QUEUE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	netif_keep_dst(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	dev->hw_features	= NETIF_F_GSO_SOFTWARE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	dev->features		= NETIF_F_SG | NETIF_F_FRAGLIST
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 		| NETIF_F_GSO_SOFTWARE
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 		| NETIF_F_HW_CSUM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 		| NETIF_F_RXCSUM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 		| NETIF_F_SCTP_CRC
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		| NETIF_F_HIGHDMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 		| NETIF_F_LLTX
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		| NETIF_F_NETNS_LOCAL
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		| NETIF_F_VLAN_CHALLENGED
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 		| NETIF_F_LOOPBACK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	dev->ethtool_ops	= eth_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	dev->header_ops		= hdr_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 	dev->netdev_ops		= dev_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 	dev->needs_free_netdev	= true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	dev->priv_destructor	= dev_destructor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) /* The loopback device is special. There is only one instance
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)  * per network namespace.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) static void loopback_setup(struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	gen_lo_setup(dev, (64 * 1024), &loopback_ethtool_ops, &eth_header_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 		     &loopback_ops, loopback_dev_free);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /* Setup and register the loopback device. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) static __net_init int loopback_net_init(struct net *net)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	struct net_device *dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 	int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	dev = alloc_netdev(0, "lo", NET_NAME_UNKNOWN, loopback_setup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 	if (!dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	dev_net_set(dev, net);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	err = register_netdev(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		goto out_free_netdev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 	BUG_ON(dev->ifindex != LOOPBACK_IFINDEX);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 	net->loopback_dev = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) out_free_netdev:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 	free_netdev(dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	if (net_eq(net, &init_net))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		panic("loopback: Failed to register netdevice: %d\n", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) /* Registered in net/core/dev.c */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) struct pernet_operations __net_initdata loopback_net_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	.init = loopback_net_init,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) /* blackhole netdevice */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) static netdev_tx_t blackhole_netdev_xmit(struct sk_buff *skb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 					 struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	kfree_skb(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	net_warn_ratelimited("%s(): Dropping skb.\n", __func__);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	return NETDEV_TX_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) static const struct net_device_ops blackhole_netdev_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	.ndo_start_xmit = blackhole_netdev_xmit,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) /* This is a dst-dummy device used specifically for invalidated
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)  * DSTs and unlike loopback, this is not per-ns.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) static void blackhole_netdev_setup(struct net_device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	gen_lo_setup(dev, ETH_MIN_MTU, NULL, NULL, &blackhole_netdev_ops, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) /* Setup and register the blackhole_netdev. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) static int __init blackhole_netdev_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	blackhole_netdev = alloc_netdev(0, "blackhole_dev", NET_NAME_UNKNOWN,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 					blackhole_netdev_setup);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	if (!blackhole_netdev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	rtnl_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	dev_init_scheduler(blackhole_netdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 	dev_activate(blackhole_netdev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	rtnl_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	blackhole_netdev->flags |= IFF_UP | IFF_RUNNING;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	dev_net_set(blackhole_netdev, &init_net);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) device_initcall(blackhole_netdev_init);