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Diffstat (limited to 'net/ieee802154/6lowpan.c')
-rw-r--r--net/ieee802154/6lowpan.c374
1 files changed, 361 insertions, 13 deletions
diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan.c
index 19d6aef..e4ecc1e 100644
--- a/net/ieee802154/6lowpan.c
+++ b/net/ieee802154/6lowpan.c
@@ -50,8 +50,6 @@
* SUCH DAMAGE.
*/
-#define DEBUG
-
#include <linux/bitops.h>
#include <linux/if_arp.h>
#include <linux/module.h>
@@ -113,6 +111,20 @@ struct lowpan_dev_record {
struct list_head list;
};
+struct lowpan_fragment {
+ struct sk_buff *skb; /* skb to be assembled */
+ spinlock_t lock; /* concurency lock */
+ u16 length; /* length to be assemled */
+ u32 bytes_rcv; /* bytes received */
+ u16 tag; /* current fragment tag */
+ struct timer_list timer; /* assembling timer */
+ struct list_head list; /* fragments list */
+};
+
+static unsigned short fragment_tag;
+static LIST_HEAD(lowpan_fragments);
+spinlock_t flist_lock;
+
static inline struct
lowpan_dev_info *lowpan_dev_info(const struct net_device *dev)
{
@@ -234,6 +246,50 @@ lowpan_uncompress_addr(struct sk_buff *skb, struct in6_addr *ipaddr,
return 0;
}
+static void
+lowpan_compress_udp_header(u8 **hc06_ptr, struct sk_buff *skb)
+{
+ struct udphdr *uh = udp_hdr(skb);
+
+ pr_debug("(%s): UDP header compression\n", __func__);
+
+ if (((uh->source & LOWPAN_NHC_UDP_4BIT_MASK) ==
+ LOWPAN_NHC_UDP_4BIT_PORT) &&
+ ((uh->dest & LOWPAN_NHC_UDP_4BIT_MASK) ==
+ LOWPAN_NHC_UDP_4BIT_PORT)) {
+ pr_debug("(%s): both ports compression to 4 bits\n", __func__);
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_11;
+ **(hc06_ptr + 1) = /* subtraction is faster */
+ (u8)((uh->dest - LOWPAN_NHC_UDP_4BIT_PORT) +
+ ((uh->source & LOWPAN_NHC_UDP_4BIT_PORT) << 4));
+ *hc06_ptr += 2;
+ } else if ((uh->dest & LOWPAN_NHC_UDP_8BIT_MASK) ==
+ LOWPAN_NHC_UDP_8BIT_PORT) {
+ pr_debug("(%s): remove 8 bits of dest\n", __func__);
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_01;
+ memcpy(*hc06_ptr + 1, &uh->source, 2);
+ **(hc06_ptr + 3) = (u8)(uh->dest - LOWPAN_NHC_UDP_8BIT_PORT);
+ *hc06_ptr += 4;
+ } else if ((uh->source & LOWPAN_NHC_UDP_8BIT_MASK) ==
+ LOWPAN_NHC_UDP_8BIT_PORT) {
+ pr_debug("(%s): remove 8 bits of source\n", __func__);
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_10;
+ memcpy(*hc06_ptr + 1, &uh->dest, 2);
+ **(hc06_ptr + 3) = (u8)(uh->source - LOWPAN_NHC_UDP_8BIT_PORT);
+ *hc06_ptr += 4;
+ } else {
+ pr_debug("(%s): can't compress header\n", __func__);
+ **hc06_ptr = LOWPAN_NHC_UDP_CS_P_00;
+ memcpy(*hc06_ptr + 1, &uh->source, 2);
+ memcpy(*hc06_ptr + 3, &uh->dest, 2);
+ *hc06_ptr += 5;
+ }
+
+ /* checksum is always inline */
+ memcpy(*hc06_ptr, &uh->check, 2);
+ *hc06_ptr += 2;
+}
+
static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
{
u8 ret;
@@ -244,6 +300,73 @@ static u8 lowpan_fetch_skb_u8(struct sk_buff *skb)
return ret;
}
+static u16 lowpan_fetch_skb_u16(struct sk_buff *skb)
+{
+ u16 ret;
+
+ BUG_ON(!pskb_may_pull(skb, 2));
+
+ ret = skb->data[0] | (skb->data[1] << 8);
+ skb_pull(skb, 2);
+ return ret;
+}
+
+static int
+lowpan_uncompress_udp_header(struct sk_buff *skb)
+{
+ struct udphdr *uh = udp_hdr(skb);
+ u8 tmp;
+
+ tmp = lowpan_fetch_skb_u8(skb);
+
+ if ((tmp & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) {
+ pr_debug("(%s): UDP header uncompression\n", __func__);
+ switch (tmp & LOWPAN_NHC_UDP_CS_P_11) {
+ case LOWPAN_NHC_UDP_CS_P_00:
+ memcpy(&uh->source, &skb->data[0], 2);
+ memcpy(&uh->dest, &skb->data[2], 2);
+ skb_pull(skb, 4);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_01:
+ memcpy(&uh->source, &skb->data[0], 2);
+ uh->dest =
+ skb->data[2] + LOWPAN_NHC_UDP_8BIT_PORT;
+ skb_pull(skb, 3);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_10:
+ uh->source = skb->data[0] + LOWPAN_NHC_UDP_8BIT_PORT;
+ memcpy(&uh->dest, &skb->data[1], 2);
+ skb_pull(skb, 3);
+ break;
+ case LOWPAN_NHC_UDP_CS_P_11:
+ uh->source =
+ LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] >> 4);
+ uh->dest =
+ LOWPAN_NHC_UDP_4BIT_PORT + (skb->data[0] & 0x0f);
+ skb_pull(skb, 1);
+ break;
+ default:
+ pr_debug("(%s) ERROR: unknown UDP format\n", __func__);
+ goto err;
+ break;
+ }
+
+ pr_debug("(%s): uncompressed UDP ports: src = %d, dst = %d\n",
+ __func__, uh->source, uh->dest);
+
+ /* copy checksum */
+ memcpy(&uh->check, &skb->data[0], 2);
+ skb_pull(skb, 2);
+ } else {
+ pr_debug("(%s): ERROR: unsupported NH format\n", __func__);
+ goto err;
+ }
+
+ return 0;
+err:
+ return -EINVAL;
+}
+
static int lowpan_header_create(struct sk_buff *skb,
struct net_device *dev,
unsigned short type, const void *_daddr,
@@ -342,8 +465,6 @@ static int lowpan_header_create(struct sk_buff *skb,
if (hdr->nexthdr == UIP_PROTO_UDP)
iphc0 |= LOWPAN_IPHC_NH_C;
-/* TODO: next header compression */
-
if ((iphc0 & LOWPAN_IPHC_NH_C) == 0) {
*hc06_ptr = hdr->nexthdr;
hc06_ptr += 1;
@@ -431,8 +552,9 @@ static int lowpan_header_create(struct sk_buff *skb,
}
}
- /* TODO: UDP header compression */
- /* TODO: Next Header compression */
+ /* UDP header compression */
+ if (hdr->nexthdr == UIP_PROTO_UDP)
+ lowpan_compress_udp_header(&hc06_ptr, skb);
head[0] = iphc0;
head[1] = iphc1;
@@ -467,6 +589,7 @@ static int lowpan_header_create(struct sk_buff *skb,
memcpy(&(sa.hwaddr), saddr, 8);
mac_cb(skb)->flags = IEEE802154_FC_TYPE_DATA;
+
return dev_hard_header(skb, lowpan_dev_info(dev)->real_dev,
type, (void *)&da, (void *)&sa, skb->len);
}
@@ -511,6 +634,21 @@ static int lowpan_skb_deliver(struct sk_buff *skb, struct ipv6hdr *hdr)
return stat;
}
+static void lowpan_fragment_timer_expired(unsigned long entry_addr)
+{
+ struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr;
+
+ pr_debug("%s: timer expired for frame with tag %d\n", __func__,
+ entry->tag);
+
+ spin_lock(&flist_lock);
+ list_del(&entry->list);
+ spin_unlock(&flist_lock);
+
+ dev_kfree_skb(entry->skb);
+ kfree(entry);
+}
+
static int
lowpan_process_data(struct sk_buff *skb)
{
@@ -525,6 +663,107 @@ lowpan_process_data(struct sk_buff *skb)
if (skb->len < 2)
goto drop;
iphc0 = lowpan_fetch_skb_u8(skb);
+
+ /* fragments assembling */
+ switch (iphc0 & LOWPAN_DISPATCH_MASK) {
+ case LOWPAN_DISPATCH_FRAG1:
+ case LOWPAN_DISPATCH_FRAGN:
+ {
+ struct lowpan_fragment *frame;
+ u8 len, offset;
+ u16 tag;
+ bool found = false;
+
+ len = lowpan_fetch_skb_u8(skb); /* frame length */
+ tag = lowpan_fetch_skb_u16(skb);
+
+ /*
+ * check if frame assembling with the same tag is
+ * already in progress
+ */
+ spin_lock(&flist_lock);
+
+ list_for_each_entry(frame, &lowpan_fragments, list)
+ if (frame->tag == tag) {
+ found = true;
+ break;
+ }
+
+ /* alloc new frame structure */
+ if (!found) {
+ frame = kzalloc(sizeof(struct lowpan_fragment),
+ GFP_ATOMIC);
+ if (!frame)
+ goto unlock_and_drop;
+
+ INIT_LIST_HEAD(&frame->list);
+
+ frame->length = (iphc0 & 7) | (len << 3);
+ frame->tag = tag;
+
+ /* allocate buffer for frame assembling */
+ frame->skb = alloc_skb(frame->length +
+ sizeof(struct ipv6hdr), GFP_ATOMIC);
+
+ if (!frame->skb) {
+ kfree(frame);
+ goto unlock_and_drop;
+ }
+
+ frame->skb->priority = skb->priority;
+ frame->skb->dev = skb->dev;
+
+ /* reserve headroom for uncompressed ipv6 header */
+ skb_reserve(frame->skb, sizeof(struct ipv6hdr));
+ skb_put(frame->skb, frame->length);
+
+ init_timer(&frame->timer);
+ /* time out is the same as for ipv6 - 60 sec */
+ frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT;
+ frame->timer.data = (unsigned long)frame;
+ frame->timer.function = lowpan_fragment_timer_expired;
+
+ add_timer(&frame->timer);
+
+ list_add_tail(&frame->list, &lowpan_fragments);
+ }
+
+ if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1)
+ goto unlock_and_drop;
+
+ offset = lowpan_fetch_skb_u8(skb); /* fetch offset */
+
+ /* if payload fits buffer, copy it */
+ if (likely((offset * 8 + skb->len) <= frame->length))
+ skb_copy_to_linear_data_offset(frame->skb, offset * 8,
+ skb->data, skb->len);
+ else
+ goto unlock_and_drop;
+
+ frame->bytes_rcv += skb->len;
+
+ /* frame assembling complete */
+ if ((frame->bytes_rcv == frame->length) &&
+ frame->timer.expires > jiffies) {
+ /* if timer haven't expired - first of all delete it */
+ del_timer(&frame->timer);
+ list_del(&frame->list);
+ spin_unlock(&flist_lock);
+
+ dev_kfree_skb(skb);
+ skb = frame->skb;
+ kfree(frame);
+ iphc0 = lowpan_fetch_skb_u8(skb);
+ break;
+ }
+ spin_unlock(&flist_lock);
+
+ return kfree_skb(skb), 0;
+ }
+ default:
+ break;
+ }
+
iphc1 = lowpan_fetch_skb_u8(skb);
_saddr = mac_cb(skb)->sa.hwaddr;
@@ -659,7 +898,10 @@ lowpan_process_data(struct sk_buff *skb)
goto drop;
}
- /* TODO: UDP header parse */
+ /* UDP data uncompression */
+ if (iphc0 & LOWPAN_IPHC_NH_C)
+ if (lowpan_uncompress_udp_header(skb))
+ goto drop;
/* Not fragmented package */
hdr.payload_len = htons(skb->len);
@@ -674,6 +916,9 @@ lowpan_process_data(struct sk_buff *skb)
lowpan_raw_dump_table(__func__, "raw header dump", (u8 *)&hdr,
sizeof(hdr));
return lowpan_skb_deliver(skb, &hdr);
+
+unlock_and_drop:
+ spin_unlock(&flist_lock);
drop:
kfree_skb(skb);
return -EINVAL;
@@ -692,18 +937,115 @@ static int lowpan_set_address(struct net_device *dev, void *p)
return 0;
}
+static int lowpan_get_mac_header_length(struct sk_buff *skb)
+{
+ /*
+ * Currently long addressing mode is supported only, so the overall
+ * header size is 21:
+ * FC SeqNum DPAN DA SA Sec
+ * 2 + 1 + 2 + 8 + 8 + 0 = 21
+ */
+ return 21;
+}
+
+static int
+lowpan_fragment_xmit(struct sk_buff *skb, u8 *head,
+ int mlen, int plen, int offset)
+{
+ struct sk_buff *frag;
+ int hlen, ret;
+
+ /* if payload length is zero, therefore it's a first fragment */
+ hlen = (plen == 0 ? LOWPAN_FRAG1_HEAD_SIZE : LOWPAN_FRAGN_HEAD_SIZE);
+
+ lowpan_raw_dump_inline(__func__, "6lowpan fragment header", head, hlen);
+
+ frag = dev_alloc_skb(hlen + mlen + plen + IEEE802154_MFR_SIZE);
+ if (!frag)
+ return -ENOMEM;
+
+ frag->priority = skb->priority;
+ frag->dev = skb->dev;
+
+ /* copy header, MFR and payload */
+ memcpy(skb_put(frag, mlen), skb->data, mlen);
+ memcpy(skb_put(frag, hlen), head, hlen);
+
+ if (plen)
+ skb_copy_from_linear_data_offset(skb, offset + mlen,
+ skb_put(frag, plen), plen);
+
+ lowpan_raw_dump_table(__func__, " raw fragment dump", frag->data,
+ frag->len);
+
+ ret = dev_queue_xmit(frag);
+
+ return ret;
+}
+
+static int
+lowpan_skb_fragmentation(struct sk_buff *skb)
+{
+ int err, header_length, payload_length, tag, offset = 0;
+ u8 head[5];
+
+ header_length = lowpan_get_mac_header_length(skb);
+ payload_length = skb->len - header_length;
+ tag = fragment_tag++;
+
+ /* first fragment header */
+ head[0] = LOWPAN_DISPATCH_FRAG1 | (payload_length & 0x7);
+ head[1] = (payload_length >> 3) & 0xff;
+ head[2] = tag & 0xff;
+ head[3] = tag >> 8;
+
+ err = lowpan_fragment_xmit(skb, head, header_length, 0, 0);
+
+ /* next fragment header */
+ head[0] &= ~LOWPAN_DISPATCH_FRAG1;
+ head[0] |= LOWPAN_DISPATCH_FRAGN;
+
+ while ((payload_length - offset > 0) && (err >= 0)) {
+ int len = LOWPAN_FRAG_SIZE;
+
+ head[4] = offset / 8;
+
+ if (payload_length - offset < len)
+ len = payload_length - offset;
+
+ err = lowpan_fragment_xmit(skb, head, header_length,
+ len, offset);
+ offset += len;
+ }
+
+ return err;
+}
+
static netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *dev)
{
- int err = 0;
+ int err = -1;
pr_debug("(%s): package xmit\n", __func__);
skb->dev = lowpan_dev_info(dev)->real_dev;
if (skb->dev == NULL) {
pr_debug("(%s) ERROR: no real wpan device found\n", __func__);
- dev_kfree_skb(skb);
- } else
+ goto error;
+ }
+
+ if (skb->len <= IEEE802154_MTU) {
err = dev_queue_xmit(skb);
+ goto out;
+ }
+
+ pr_debug("(%s): frame is too big, fragmentation is needed\n",
+ __func__);
+ err = lowpan_skb_fragmentation(skb);
+error:
+ dev_kfree_skb(skb);
+out:
+ if (err < 0)
+ pr_debug("(%s): ERROR: xmit failed\n", __func__);
return (err < 0 ? NETDEV_TX_BUSY : NETDEV_TX_OK);
}
@@ -730,13 +1072,12 @@ static void lowpan_setup(struct net_device *dev)
dev->addr_len = IEEE802154_ADDR_LEN;
memset(dev->broadcast, 0xff, IEEE802154_ADDR_LEN);
dev->type = ARPHRD_IEEE802154;
- dev->features = NETIF_F_NO_CSUM;
/* Frame Control + Sequence Number + Address fields + Security Header */
dev->hard_header_len = 2 + 1 + 20 + 14;
dev->needed_tailroom = 2; /* FCS */
dev->mtu = 1281;
dev->tx_queue_len = 0;
- dev->flags = IFF_NOARP | IFF_BROADCAST;
+ dev->flags = IFF_BROADCAST | IFF_MULTICAST;
dev->watchdog_timeo = 0;
dev->netdev_ops = &lowpan_netdev_ops;
@@ -765,8 +1106,15 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
goto drop;
/* check that it's our buffer */
- if ((skb->data[0] & 0xe0) == 0x60)
+ switch (skb->data[0] & 0xe0) {
+ case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
+ case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
+ case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
lowpan_process_data(skb);
+ break;
+ default:
+ break;
+ }
return NET_RX_SUCCESS;
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