aoenet.c

  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 <linux/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	strscpy(aoe_iflist, str, IFLISTSZ);
 43	return 1;
 44}
 45
 46__setup("aoe_iflist=", aoe_iflist_setup);
 47#endif
 48
 49static spinlock_t txlock;
 50static struct sk_buff_head skbtxq;
 51
 52/* enters with txlock held */
 53static int
 54tx(int id) __must_hold(&txlock)
 55{
 56	struct sk_buff *skb;
 57	struct net_device *ifp;
 58
 59	while ((skb = skb_dequeue(&skbtxq))) {
 60		spin_unlock_irq(&txlock);
 61		ifp = skb->dev;
 62		if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
 63			pr_warn("aoe: packet could not be sent on %s.  %s\n",
 64				ifp ? ifp->name : "netif",
 65				"consider increasing tx_queue_len");
 66		dev_put(ifp);
 67		spin_lock_irq(&txlock);
 68	}
 69	return 0;
 70}
 71
 72int
 73is_aoe_netif(struct net_device *ifp)
 74{
 75	register char *p, *q;
 76	register int len;
 77
 78	if (aoe_iflist[0] == '\0')
 79		return 1;
 80
 81	p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
 82	for (; *p; p = q + strspn(q, WHITESPACE)) {
 83		q = p + strcspn(p, WHITESPACE);
 84		if (q != p)
 85			len = q - p;
 86		else
 87			len = strlen(p); /* last token in aoe_iflist */
 88
 89		if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
 90			return 1;
 91		if (q == p)
 92			break;
 93	}
 94
 95	return 0;
 96}
 97
 98int
 99set_aoe_iflist(const char __user *user_str, size_t size)
100{
101	if (size >= IFLISTSZ)
102		return -EINVAL;
103
104	if (copy_from_user(aoe_iflist, user_str, size)) {
105		printk(KERN_INFO "aoe: copy from user failed\n");
106		return -EFAULT;
107	}
108	aoe_iflist[size] = 0x00;
109	return 0;
110}
111
112void
113aoenet_xmit(struct sk_buff_head *queue)
114{
115	struct sk_buff *skb, *tmp;
116	ulong flags;
117
118	skb_queue_walk_safe(queue, skb, tmp) {
119		__skb_unlink(skb, queue);
120		spin_lock_irqsave(&txlock, flags);
121		skb_queue_tail(&skbtxq, skb);
122		spin_unlock_irqrestore(&txlock, flags);
123		wake_up(&txwq);
124	}
125}
126
127/*
128 * (1) len doesn't include the header by default.  I want this.
129 */
130static int
131aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
132{
133	struct aoe_hdr *h;
134	struct aoe_atahdr *ah;
135	u32 n;
136	int sn;
137
138	if (dev_net(ifp) != &init_net)
139		goto exit;
140
141	skb = skb_share_check(skb, GFP_ATOMIC);
142	if (skb == NULL)
143		return 0;
144	if (!is_aoe_netif(ifp))
145		goto exit;
146	skb_push(skb, ETH_HLEN);	/* (1) */
147	sn = sizeof(*h) + sizeof(*ah);
148	if (skb->len >= sn) {
149		sn -= skb_headlen(skb);
150		if (sn > 0 && !__pskb_pull_tail(skb, sn))
151			goto exit;
152	}
153	h = (struct aoe_hdr *) skb->data;
154	n = get_unaligned_be32(&h->tag);
155	if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
156		goto exit;
157
158	if (h->verfl & AOEFL_ERR) {
159		n = h->err;
160		if (n > NECODES)
161			n = 0;
162		if (net_ratelimit())
163			printk(KERN_ERR
164				"%s%d.%d@%s; ecode=%d '%s'\n",
165				"aoe: error packet from ",
166				get_unaligned_be16(&h->major),
167				h->minor, skb->dev->name,
168				h->err, aoe_errlist[n]);
169		goto exit;
170	}
171
172	switch (h->cmd) {
173	case AOECMD_ATA:
174		/* ata_rsp may keep skb for later processing or give it back */
175		skb = aoecmd_ata_rsp(skb);
176		break;
177	case AOECMD_CFG:
178		aoecmd_cfg_rsp(skb);
179		break;
180	default:
181		if (h->cmd >= AOECMD_VEND_MIN)
182			break;	/* don't complain about vendor commands */
183		pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
184		break;
185	}
186
187	if (!skb)
188		return 0;
189exit:
190	dev_kfree_skb(skb);
191	return 0;
192}
193
194static struct packet_type aoe_pt __read_mostly = {
195	.type = __constant_htons(ETH_P_AOE),
196	.func = aoenet_rcv,
197};
198
199int __init
200aoenet_init(void)
201{
202	skb_queue_head_init(&skbtxq);
203	init_waitqueue_head(&txwq);
204	spin_lock_init(&txlock);
205	kts.lock = &txlock;
206	kts.fn = tx;
207	kts.waitq = &txwq;
208	kts.id = 0;
209	snprintf(kts.name, sizeof(kts.name), "aoe_tx%d", kts.id);
210	if (aoe_ktstart(&kts))
211		return -EAGAIN;
212	dev_add_pack(&aoe_pt);
213	return 0;
214}
215
216void
217aoenet_exit(void)
218{
219	aoe_ktstop(&kts);
220	skb_queue_purge(&skbtxq);
221	dev_remove_pack(&aoe_pt);
222}
223