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 dev_put(ifp);
68 spin_lock_irq(&txlock);
69 }
70 return 0;
71 }
72
73 int
is_aoe_netif(struct net_device * ifp)74 is_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
99 int
set_aoe_iflist(const char __user * user_str,size_t size)100 set_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
113 void
aoenet_xmit(struct sk_buff_head * queue)114 aoenet_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 */
131 static int
aoenet_rcv(struct sk_buff * skb,struct net_device * ifp,struct packet_type * pt,struct net_device * orig_dev)132 aoenet_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;
190 exit:
191 dev_kfree_skb(skb);
192 return 0;
193 }
194
195 static struct packet_type aoe_pt __read_mostly = {
196 .type = __constant_htons(ETH_P_AOE),
197 .func = aoenet_rcv,
198 };
199
200 int __init
aoenet_init(void)201 aoenet_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
217 void
aoenet_exit(void)218 aoenet_exit(void)
219 {
220 aoe_ktstop(&kts);
221 skb_queue_purge(&skbtxq);
222 dev_remove_pack(&aoe_pt);
223 }
224
225