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 
18 static 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 
28 enum {
29 	IFLISTSZ = 1024,
30 };
31 
32 static char aoe_iflist[IFLISTSZ];
33 module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
34 MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=dev1[,dev2...]");
35 
36 static wait_queue_head_t txwq;
37 static struct ktstate kts;
38 
39 #ifndef MODULE
aoe_iflist_setup(char * str)40 static 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 
50 static spinlock_t txlock;
51 static struct sk_buff_head skbtxq;
52 
53 /* enters with txlock held */
54 static int
tx(int id)55 tx(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 		spin_lock_irq(&txlock);
68 	}
69 	return 0;
70 }
71 
72 int
is_aoe_netif(struct net_device * ifp)73 is_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 
98 int
set_aoe_iflist(const char __user * user_str,size_t size)99 set_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 
112 void
aoenet_xmit(struct sk_buff_head * queue)113 aoenet_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  */
130 static int
aoenet_rcv(struct sk_buff * skb,struct net_device * ifp,struct packet_type * pt,struct net_device * orig_dev)131 aoenet_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;
189 exit:
190 	dev_kfree_skb(skb);
191 	return 0;
192 }
193 
194 static struct packet_type aoe_pt __read_mostly = {
195 	.type = __constant_htons(ETH_P_AOE),
196 	.func = aoenet_rcv,
197 };
198 
199 int __init
aoenet_init(void)200 aoenet_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 
216 void
aoenet_exit(void)217 aoenet_exit(void)
218 {
219 	aoe_ktstop(&kts);
220 	skb_queue_purge(&skbtxq);
221 	dev_remove_pack(&aoe_pt);
222 }
223 
224