summaryrefslogtreecommitdiffstats
path: root/drivers/block/aoe/aoenet.c
blob: 71d3ea8d30062cc85b7edba1e4f8270673f6a829 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
/* Copyright (c) 2012 Coraid, Inc.  See COPYING for GPL terms. */
/*
 * aoenet.c
 * Ethernet portion of AoE driver
 */

#include <linux/gfp.h>
#include <linux/hdreg.h>
#include <linux/blkdev.h>
#include <linux/netdevice.h>
#include <linux/moduleparam.h>
#include <net/net_namespace.h>
#include <asm/unaligned.h>
#include "aoe.h"

#define NECODES 5

static char *aoe_errlist[] =
{
	"no such error",
	"unrecognized command code",
	"bad argument parameter",
	"device unavailable",
	"config string present",
	"unsupported version"
};

enum {
	IFLISTSZ = 1024,
};

static char aoe_iflist[IFLISTSZ];
module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=dev1[,dev2...]");

static wait_queue_head_t txwq;
static struct ktstate kts;

#ifndef MODULE
static int __init aoe_iflist_setup(char *str)
{
	strncpy(aoe_iflist, str, IFLISTSZ);
	aoe_iflist[IFLISTSZ - 1] = '\0';
	return 1;
}

__setup("aoe_iflist=", aoe_iflist_setup);
#endif

static spinlock_t txlock;
static struct sk_buff_head skbtxq;

/* enters with txlock held */
static int
tx(void) __must_hold(&txlock)
{
	struct sk_buff *skb;
	struct net_device *ifp;

	while ((skb = skb_dequeue(&skbtxq))) {
		spin_unlock_irq(&txlock);
		ifp = skb->dev;
		if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
			pr_warn("aoe: packet could not be sent on %s.  %s\n",
				ifp ? ifp->name : "netif",
				"consider increasing tx_queue_len");
		spin_lock_irq(&txlock);
	}
	return 0;
}

int
is_aoe_netif(struct net_device *ifp)
{
	register char *p, *q;
	register int len;

	if (aoe_iflist[0] == '\0')
		return 1;

	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
	for (; *p; p = q + strspn(q, WHITESPACE)) {
		q = p + strcspn(p, WHITESPACE);
		if (q != p)
			len = q - p;
		else
			len = strlen(p); /* last token in aoe_iflist */

		if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
			return 1;
		if (q == p)
			break;
	}

	return 0;
}

int
set_aoe_iflist(const char __user *user_str, size_t size)
{
	if (size >= IFLISTSZ)
		return -EINVAL;

	if (copy_from_user(aoe_iflist, user_str, size)) {
		printk(KERN_INFO "aoe: copy from user failed\n");
		return -EFAULT;
	}
	aoe_iflist[size] = 0x00;
	return 0;
}

void
aoenet_xmit(struct sk_buff_head *queue)
{
	struct sk_buff *skb, *tmp;
	ulong flags;

	skb_queue_walk_safe(queue, skb, tmp) {
		__skb_unlink(skb, queue);
		spin_lock_irqsave(&txlock, flags);
		skb_queue_tail(&skbtxq, skb);
		spin_unlock_irqrestore(&txlock, flags);
		wake_up(&txwq);
	}
}

/*
 * (1) len doesn't include the header by default.  I want this.
 */
static int
aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
{
	struct aoe_hdr *h;
	struct aoe_atahdr *ah;
	u32 n;
	int sn;

	if (dev_net(ifp) != &init_net)
		goto exit;

	skb = skb_share_check(skb, GFP_ATOMIC);
	if (skb == NULL)
		return 0;
	if (!is_aoe_netif(ifp))
		goto exit;
	skb_push(skb, ETH_HLEN);	/* (1) */
	sn = sizeof(*h) + sizeof(*ah);
	if (skb->len >= sn) {
		sn -= skb_headlen(skb);
		if (sn > 0 && !__pskb_pull_tail(skb, sn))
			goto exit;
	}
	h = (struct aoe_hdr *) skb->data;
	n = get_unaligned_be32(&h->tag);
	if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
		goto exit;

	if (h->verfl & AOEFL_ERR) {
		n = h->err;
		if (n > NECODES)
			n = 0;
		if (net_ratelimit())
			printk(KERN_ERR
				"%s%d.%d@%s; ecode=%d '%s'\n",
				"aoe: error packet from ",
				get_unaligned_be16(&h->major),
				h->minor, skb->dev->name,
				h->err, aoe_errlist[n]);
		goto exit;
	}

	switch (h->cmd) {
	case AOECMD_ATA:
		/* ata_rsp may keep skb for later processing or give it back */
		skb = aoecmd_ata_rsp(skb);
		break;
	case AOECMD_CFG:
		aoecmd_cfg_rsp(skb);
		break;
	default:
		if (h->cmd >= AOECMD_VEND_MIN)
			break;	/* don't complain about vendor commands */
		pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
		break;
	}

	if (!skb)
		return 0;
exit:
	dev_kfree_skb(skb);
	return 0;
}

static struct packet_type aoe_pt __read_mostly = {
	.type = __constant_htons(ETH_P_AOE),
	.func = aoenet_rcv,
};

int __init
aoenet_init(void)
{
	skb_queue_head_init(&skbtxq);
	init_waitqueue_head(&txwq);
	spin_lock_init(&txlock);
	kts.lock = &txlock;
	kts.fn = tx;
	kts.waitq = &txwq;
	kts.name = "aoe_tx";
	if (aoe_ktstart(&kts))
		return -EAGAIN;
	dev_add_pack(&aoe_pt);
	return 0;
}

void
aoenet_exit(void)
{
	aoe_ktstop(&kts);
	skb_queue_purge(&skbtxq);
	dev_remove_pack(&aoe_pt);
}