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