drivers/block/aoe/aoenet.c

   1 /* Copyright (c) 2012 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
  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
  55 tx(void)
  56 {
  57         struct sk_buff *skb;
  58
  59         while ((skb = skb_dequeue(&skbtxq))) {
  60                 spin_unlock_irq(&txlock);
  61                 dev_queue_xmit(skb);
  62                 spin_lock_irq(&txlock);
  63         }
  64         return 0;
  65 }
  66
  67 int
  68 is_aoe_netif(struct net_device *ifp)
  69 {
  70         register char *p, *q;
  71         register int len;
  72
  73         if (aoe_iflist[0] == '\0')
  74                 return 1;
  75
  76         p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
  77         for (; *p; p = q + strspn(q, WHITESPACE)) {
  78                 q = p + strcspn(p, WHITESPACE);
  79                 if (q != p)
  80                         len = q - p;
  81                 else
  82                         len = strlen(p); /* last token in aoe_iflist */
  83
  84                 if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
  85                         return 1;
  86                 if (q == p)
  87                         break;
  88         }
  89
  90         return 0;
  91 }
  92
  93 int
  94 set_aoe_iflist(const char __user *user_str, size_t size)
  95 {
  96         if (size >= IFLISTSZ)
  97                 return -EINVAL;
  98
  99         if (copy_from_user(aoe_iflist, user_str, size)) {
 100                 printk(KERN_INFO "aoe: copy from user failed\n");
 101                 return -EFAULT;
 102         }
 103         aoe_iflist[size] = 0x00;
 104         return 0;
 105 }
 106
 107 void
 108 aoenet_xmit(struct sk_buff_head *queue)
 109 {
 110         struct sk_buff *skb, *tmp;
 111         ulong flags;
 112
 113         skb_queue_walk_safe(queue, skb, tmp) {
 114                 __skb_unlink(skb, queue);
 115                 spin_lock_irqsave(&txlock, flags);
 116                 skb_queue_tail(&skbtxq, skb);
 117                 spin_unlock_irqrestore(&txlock, flags);
 118                 wake_up(&txwq);
 119         }
 120 }
 121
 122 /*
 123  * (1) len doesn't include the header by default.  I want this.
 124  */
 125 static int
 126 aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
 127 {
 128         struct aoe_hdr *h;
 129         struct aoe_atahdr *ah;
 130         u32 n;
 131         int sn;
 132
 133         if (dev_net(ifp) != &init_net)
 134                 goto exit;
 135
 136         skb = skb_share_check(skb, GFP_ATOMIC);
 137         if (skb == NULL)
 138                 return 0;
 139         if (!is_aoe_netif(ifp))
 140                 goto exit;
 141         skb_push(skb, ETH_HLEN);        /* (1) */
 142         sn = sizeof(*h) + sizeof(*ah);
 143         if (skb->len >= sn) {
 144                 sn -= skb_headlen(skb);
 145                 if (sn > 0 && !__pskb_pull_tail(skb, sn))
 146                         goto exit;
 147         }
 148         h = (struct aoe_hdr *) skb->data;
 149         n = get_unaligned_be32(&h->tag);
 150         if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
 151                 goto exit;
 152
 153         if (h->verfl & AOEFL_ERR) {
 154                 n = h->err;
 155                 if (n > NECODES)
 156                         n = 0;
 157                 if (net_ratelimit())
 158                         printk(KERN_ERR
 159                                 "%s%d.%d@%s; ecode=%d '%s'\n",
 160                                 "aoe: error packet from ",
 161                                 get_unaligned_be16(&h->major),
 162                                 h->minor, skb->dev->name,
 163                                 h->err, aoe_errlist[n]);
 164                 goto exit;
 165         }
 166
 167         switch (h->cmd) {
 168         case AOECMD_ATA:
 169                 /* ata_rsp may keep skb for later processing or give it back */
 170                 skb = aoecmd_ata_rsp(skb);
 171                 break;
 172         case AOECMD_CFG:
 173                 aoecmd_cfg_rsp(skb);
 174                 break;
 175         default:
 176                 if (h->cmd >= AOECMD_VEND_MIN)
 177                         break;  /* don't complain about vendor commands */
 178                 pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
 179                 break;
 180         }
 181
 182         if (!skb)
 183                 return 0;
 184 exit:
 185         dev_kfree_skb(skb);
 186         return 0;
 187 }
 188
 189 static struct packet_type aoe_pt __read_mostly = {
 190         .type = __constant_htons(ETH_P_AOE),
 191         .func = aoenet_rcv,
 192 };
 193
 194 int __init
 195 aoenet_init(void)
 196 {
 197         skb_queue_head_init(&skbtxq);
 198         init_waitqueue_head(&txwq);
 199         spin_lock_init(&txlock);
 200         kts.lock = &txlock;
 201         kts.fn = tx;
 202         kts.waitq = &txwq;
 203         kts.name = "aoe_tx";
 204         if (aoe_ktstart(&kts))
 205                 return -EAGAIN;
 206         dev_add_pack(&aoe_pt);
 207         return 0;
 208 }
 209
 210 void
 211 aoenet_exit(void)
 212 {
 213         aoe_ktstop(&kts);
 214         skb_queue_purge(&skbtxq);
 215         dev_remove_pack(&aoe_pt);
 216 }
 217