1/* Copyright (c) 2013 Coraid, Inc.  See COPYING for GPL terms. */
2/*
3 * aoenet.c
4 * Ethernet portion of AoE driver
5 */
6
7#include <linux/gfp.h>
8#include <linux/hdreg.h>
9#include <linux/blkdev.h>
10#include <linux/netdevice.h>
11#include <linux/moduleparam.h>
12#include <net/net_namespace.h>
13#include <asm/unaligned.h>
14#include "aoe.h"
15
16#define NECODES 5
17
18static char *aoe_errlist[] =
19{
20	"no such error",
21	"unrecognized command code",
22	"bad argument parameter",
23	"device unavailable",
24	"config string present",
25	"unsupported version"
26};
27
28enum {
29	IFLISTSZ = 1024,
30};
31
32static char aoe_iflist[IFLISTSZ];
33module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
34MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=dev1[,dev2...]");
35
36static wait_queue_head_t txwq;
37static struct ktstate kts;
38
39#ifndef MODULE
40static int __init aoe_iflist_setup(char *str)
41{
42	strncpy(aoe_iflist, str, IFLISTSZ);
43	aoe_iflist[IFLISTSZ - 1] = '\0';
44	return 1;
45}
46
47__setup("aoe_iflist=", aoe_iflist_setup);
48#endif
49
50static spinlock_t txlock;
51static struct sk_buff_head skbtxq;
52
53/* enters with txlock held */
54static int
55tx(int id) __must_hold(&txlock)
56{
57	struct sk_buff *skb;
58	struct net_device *ifp;
59
60	while ((skb = skb_dequeue(&skbtxq))) {
61		spin_unlock_irq(&txlock);
62		ifp = skb->dev;
63		if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
64			pr_warn("aoe: packet could not be sent on %s.  %s\n",
65				ifp ? ifp->name : "netif",
66				"consider increasing tx_queue_len");
67		dev_put(ifp);
68		spin_lock_irq(&txlock);
69	}
70	return 0;
71}
72
73int
74is_aoe_netif(struct net_device *ifp)
75{
76	register char *p, *q;
77	register int len;
78
79	if (aoe_iflist[0] == '\0')
80		return 1;
81
82	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
83	for (; *p; p = q + strspn(q, WHITESPACE)) {
84		q = p + strcspn(p, WHITESPACE);
85		if (q != p)
86			len = q - p;
87		else
88			len = strlen(p); /* last token in aoe_iflist */
89
90		if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
91			return 1;
92		if (q == p)
93			break;
94	}
95
96	return 0;
97}
98
99int
100set_aoe_iflist(const char __user *user_str, size_t size)
101{
102	if (size >= IFLISTSZ)
103		return -EINVAL;
104
105	if (copy_from_user(aoe_iflist, user_str, size)) {
106		printk(KERN_INFO "aoe: copy from user failed\n");
107		return -EFAULT;
108	}
109	aoe_iflist[size] = 0x00;
110	return 0;
111}
112
113void
114aoenet_xmit(struct sk_buff_head *queue)
115{
116	struct sk_buff *skb, *tmp;
117	ulong flags;
118
119	skb_queue_walk_safe(queue, skb, tmp) {
120		__skb_unlink(skb, queue);
121		spin_lock_irqsave(&txlock, flags);
122		skb_queue_tail(&skbtxq, skb);
123		spin_unlock_irqrestore(&txlock, flags);
124		wake_up(&txwq);
125	}
126}
127
128/*
129 * (1) len doesn't include the header by default.  I want this.
130 */
131static int
132aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
133{
134	struct aoe_hdr *h;
135	struct aoe_atahdr *ah;
136	u32 n;
137	int sn;
138
139	if (dev_net(ifp) != &init_net)
140		goto exit;
141
142	skb = skb_share_check(skb, GFP_ATOMIC);
143	if (skb == NULL)
144		return 0;
145	if (!is_aoe_netif(ifp))
146		goto exit;
147	skb_push(skb, ETH_HLEN);	/* (1) */
148	sn = sizeof(*h) + sizeof(*ah);
149	if (skb->len >= sn) {
150		sn -= skb_headlen(skb);
151		if (sn > 0 && !__pskb_pull_tail(skb, sn))
152			goto exit;
153	}
154	h = (struct aoe_hdr *) skb->data;
155	n = get_unaligned_be32(&h->tag);
156	if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
157		goto exit;
158
159	if (h->verfl & AOEFL_ERR) {
160		n = h->err;
161		if (n > NECODES)
162			n = 0;
163		if (net_ratelimit())
164			printk(KERN_ERR
165				"%s%d.%d@%s; ecode=%d '%s'\n",
166				"aoe: error packet from ",
167				get_unaligned_be16(&h->major),
168				h->minor, skb->dev->name,
169				h->err, aoe_errlist[n]);
170		goto exit;
171	}
172
173	switch (h->cmd) {
174	case AOECMD_ATA:
175		/* ata_rsp may keep skb for later processing or give it back */
176		skb = aoecmd_ata_rsp(skb);
177		break;
178	case AOECMD_CFG:
179		aoecmd_cfg_rsp(skb);
180		break;
181	default:
182		if (h->cmd >= AOECMD_VEND_MIN)
183			break;	/* don't complain about vendor commands */
184		pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
185		break;
186	}
187
188	if (!skb)
189		return 0;
190exit:
191	dev_kfree_skb(skb);
192	return 0;
193}
194
195static struct packet_type aoe_pt __read_mostly = {
196	.type = __constant_htons(ETH_P_AOE),
197	.func = aoenet_rcv,
198};
199
200int __init
201aoenet_init(void)
202{
203	skb_queue_head_init(&skbtxq);
204	init_waitqueue_head(&txwq);
205	spin_lock_init(&txlock);
206	kts.lock = &txlock;
207	kts.fn = tx;
208	kts.waitq = &txwq;
209	kts.id = 0;
210	snprintf(kts.name, sizeof(kts.name), "aoe_tx%d", kts.id);
211	if (aoe_ktstart(&kts))
212		return -EAGAIN;
213	dev_add_pack(&aoe_pt);
214	return 0;
215}
216
217void
218aoenet_exit(void)
219{
220	aoe_ktstop(&kts);
221	skb_queue_purge(&skbtxq);
222	dev_remove_pack(&aoe_pt);
223}
224
225