block/aoe/aoenet.c

0001 /* Copyright (c) 2013 Coraid, Inc.  See COPYING for GPL terms. */
0002 /*
0003  * aoenet.c
0004  * Ethernet portion of AoE driver
0005  */
0006
0007 #include <linux/gfp.h>
0008 #include <linux/hdreg.h>
0009 #include <linux/blkdev.h>
0010 #include <linux/netdevice.h>
0011 #include <linux/moduleparam.h>
0012 #include <net/net_namespace.h>
0013 #include <asm/unaligned.h>
0014 #include "aoe.h"
0015
0016 #define NECODES 5
0017
0018 static char *aoe_errlist[] =
0019 {
0020     "no such error",
0021     "unrecognized command code",
0022     "bad argument parameter",
0023     "device unavailable",
0024     "config string present",
0025     "unsupported version"
0026 };
0027
0028 enum {
0029     IFLISTSZ = 1024,
0030 };
0031
0032 static char aoe_iflist[IFLISTSZ];
0033 module_param_string(aoe_iflist, aoe_iflist, IFLISTSZ, 0600);
0034 MODULE_PARM_DESC(aoe_iflist, "aoe_iflist=dev1[,dev2...]");
0035
0036 static wait_queue_head_t txwq;
0037 static struct ktstate kts;
0038
0039 #ifndef MODULE
0040 static int __init aoe_iflist_setup(char *str)
0041 {
0042     strncpy(aoe_iflist, str, IFLISTSZ);
0043     aoe_iflist[IFLISTSZ - 1] = '\0';
0044     return 1;
0045 }
0046
0047 __setup("aoe_iflist=", aoe_iflist_setup);
0048 #endif
0049
0050 static spinlock_t txlock;
0051 static struct sk_buff_head skbtxq;
0052
0053 /* enters with txlock held */
0054 static int
0055 tx(int id) __must_hold(&txlock)
0056 {
0057     struct sk_buff *skb;
0058     struct net_device *ifp;
0059
0060     while ((skb = skb_dequeue(&skbtxq))) {
0061         spin_unlock_irq(&txlock);
0062         ifp = skb->dev;
0063         if (dev_queue_xmit(skb) == NET_XMIT_DROP && net_ratelimit())
0064             pr_warn("aoe: packet could not be sent on %s.  %s\n",
0065                 ifp ? ifp->name : "netif",
0066                 "consider increasing tx_queue_len");
0067         spin_lock_irq(&txlock);
0068     }
0069     return 0;
0070 }
0071
0072 int
0073 is_aoe_netif(struct net_device *ifp)
0074 {
0075     register char *p, *q;
0076     register int len;
0077
0078     if (aoe_iflist[0] == '\0')
0079         return 1;
0080
0081     p = aoe_iflist + strspn(aoe_iflist, WHITESPACE);
0082     for (; *p; p = q + strspn(q, WHITESPACE)) {
0083         q = p + strcspn(p, WHITESPACE);
0084         if (q != p)
0085             len = q - p;
0086         else
0087             len = strlen(p); /* last token in aoe_iflist */
0088
0089         if (strlen(ifp->name) == len && !strncmp(ifp->name, p, len))
0090             return 1;
0091         if (q == p)
0092             break;
0093     }
0094
0095     return 0;
0096 }
0097
0098 int
0099 set_aoe_iflist(const char __user *user_str, size_t size)
0100 {
0101     if (size >= IFLISTSZ)
0102         return -EINVAL;
0103
0104     if (copy_from_user(aoe_iflist, user_str, size)) {
0105         printk(KERN_INFO "aoe: copy from user failed\n");
0106         return -EFAULT;
0107     }
0108     aoe_iflist[size] = 0x00;
0109     return 0;
0110 }
0111
0112 void
0113 aoenet_xmit(struct sk_buff_head *queue)
0114 {
0115     struct sk_buff *skb, *tmp;
0116     ulong flags;
0117
0118     skb_queue_walk_safe(queue, skb, tmp) {
0119         __skb_unlink(skb, queue);
0120         spin_lock_irqsave(&txlock, flags);
0121         skb_queue_tail(&skbtxq, skb);
0122         spin_unlock_irqrestore(&txlock, flags);
0123         wake_up(&txwq);
0124     }
0125 }
0126
0127 /*
0128  * (1) len doesn't include the header by default.  I want this.
0129  */
0130 static int
0131 aoenet_rcv(struct sk_buff *skb, struct net_device *ifp, struct packet_type *pt, struct net_device *orig_dev)
0132 {
0133     struct aoe_hdr *h;
0134     struct aoe_atahdr *ah;
0135     u32 n;
0136     int sn;
0137
0138     if (dev_net(ifp) != &init_net)
0139         goto exit;
0140
0141     skb = skb_share_check(skb, GFP_ATOMIC);
0142     if (skb == NULL)
0143         return 0;
0144     if (!is_aoe_netif(ifp))
0145         goto exit;
0146     skb_push(skb, ETH_HLEN);    /* (1) */
0147     sn = sizeof(*h) + sizeof(*ah);
0148     if (skb->len >= sn) {
0149         sn -= skb_headlen(skb);
0150         if (sn > 0 && !__pskb_pull_tail(skb, sn))
0151             goto exit;
0152     }
0153     h = (struct aoe_hdr *) skb->data;
0154     n = get_unaligned_be32(&h->tag);
0155     if ((h->verfl & AOEFL_RSP) == 0 || (n & 1<<31))
0156         goto exit;
0157
0158     if (h->verfl & AOEFL_ERR) {
0159         n = h->err;
0160         if (n > NECODES)
0161             n = 0;
0162         if (net_ratelimit())
0163             printk(KERN_ERR
0164                 "%s%d.%d@%s; ecode=%d '%s'\n",
0165                 "aoe: error packet from ",
0166                 get_unaligned_be16(&h->major),
0167                 h->minor, skb->dev->name,
0168                 h->err, aoe_errlist[n]);
0169         goto exit;
0170     }
0171
0172     switch (h->cmd) {
0173     case AOECMD_ATA:
0174         /* ata_rsp may keep skb for later processing or give it back */
0175         skb = aoecmd_ata_rsp(skb);
0176         break;
0177     case AOECMD_CFG:
0178         aoecmd_cfg_rsp(skb);
0179         break;
0180     default:
0181         if (h->cmd >= AOECMD_VEND_MIN)
0182             break;  /* don't complain about vendor commands */
0183         pr_info("aoe: unknown AoE command type 0x%02x\n", h->cmd);
0184         break;
0185     }
0186
0187     if (!skb)
0188         return 0;
0189 exit:
0190     dev_kfree_skb(skb);
0191     return 0;
0192 }
0193
0194 static struct packet_type aoe_pt __read_mostly = {
0195     .type = __constant_htons(ETH_P_AOE),
0196     .func = aoenet_rcv,
0197 };
0198
0199 int __init
0200 aoenet_init(void)
0201 {
0202     skb_queue_head_init(&skbtxq);
0203     init_waitqueue_head(&txwq);
0204     spin_lock_init(&txlock);
0205     kts.lock = &txlock;
0206     kts.fn = tx;
0207     kts.waitq = &txwq;
0208     kts.id = 0;
0209     snprintf(kts.name, sizeof(kts.name), "aoe_tx%d", kts.id);
0210     if (aoe_ktstart(&kts))
0211         return -EAGAIN;
0212     dev_add_pack(&aoe_pt);
0213     return 0;
0214 }
0215
0216 void
0217 aoenet_exit(void)
0218 {
0219     aoe_ktstop(&kts);
0220     skb_queue_purge(&skbtxq);
0221     dev_remove_pack(&aoe_pt);
0222 }
0223