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