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) __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
  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
  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
 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
 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
 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.name = "aoe_tx";
 209         if (aoe_ktstart(&kts))
 210                 return -EAGAIN;
 211         dev_add_pack(&aoe_pt);
 212         return 0;
 213 }
 214
 215 void
 216 aoenet_exit(void)
 217 {
 218         aoe_ktstop(&kts);
 219         skb_queue_purge(&skbtxq);
 220         dev_remove_pack(&aoe_pt);
 221 }
 222