linux/drivers/block/aoe/aoenet.c
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   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
  18static 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
  28enum {
  29        IFLISTSZ = 1024,
  30};
  31
  32static char aoe_iflist[IFLISTSZ];
  33module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
  34MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=dev1[,dev2...]");
  35
  36static wait_queue_head_t txwq;
  37static struct ktstate kts;
  38
  39#ifndef MODULE
  40static 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
  50static spinlock_t txlock;
  51static struct sk_buff_head skbtxq;
  52
  53/* enters with txlock held */
  54static int
  55tx(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
  72int
  73is_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
  98int
  99set_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
 112void
 113aoenet_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 */
 130static int
 131aoenet_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;
 189exit:
 190        dev_kfree_skb(skb);
 191        return 0;
 192}
 193
 194static struct packet_type aoe_pt __read_mostly = {
 195        .type = __constant_htons(ETH_P_AOE),
 196        .func = aoenet_rcv,
 197};
 198
 199int __init
 200aoenet_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
 215void
 216aoenet_exit(void)
 217{
 218        aoe_ktstop(&kts);
 219        skb_queue_purge(&skbtxq);
 220        dev_remove_pack(&aoe_pt);
 221}
 222
 223