#include <linux/if_arp.h>
#include <net/6lowpan.h>
+#include <net/mac802154.h>
#include <net/ieee802154_netdev.h>
#include "6lowpan_i.h"
-static int lowpan_give_skb_to_devices(struct sk_buff *skb,
- struct net_device *dev)
-{
- struct lowpan_dev_record *entry;
- struct sk_buff *skb_cp;
- int stat = NET_RX_SUCCESS;
+#define LOWPAN_DISPATCH_FIRST 0xc0
+#define LOWPAN_DISPATCH_FRAG_MASK 0xf8
+
+#define LOWPAN_DISPATCH_NALP 0x00
+#define LOWPAN_DISPATCH_ESC 0x40
+#define LOWPAN_DISPATCH_HC1 0x42
+#define LOWPAN_DISPATCH_DFF 0x43
+#define LOWPAN_DISPATCH_BC0 0x50
+#define LOWPAN_DISPATCH_MESH 0x80
+static int lowpan_give_skb_to_device(struct sk_buff *skb)
+{
skb->protocol = htons(ETH_P_IPV6);
- skb->pkt_type = PACKET_HOST;
+ skb->dev->stats.rx_packets++;
+ skb->dev->stats.rx_bytes += skb->len;
- rcu_read_lock();
- list_for_each_entry_rcu(entry, &lowpan_devices, list)
- if (lowpan_dev_info(entry->ldev)->real_dev == skb->dev) {
- skb_cp = skb_copy(skb, GFP_ATOMIC);
- if (!skb_cp) {
- kfree_skb(skb);
- rcu_read_unlock();
- return NET_RX_DROP;
- }
+ return netif_rx(skb);
+}
- skb_cp->dev = entry->ldev;
- stat = netif_rx(skb_cp);
- if (stat == NET_RX_DROP)
- break;
- }
- rcu_read_unlock();
+static int lowpan_rx_handlers_result(struct sk_buff *skb, lowpan_rx_result res)
+{
+ switch (res) {
+ case RX_CONTINUE:
+ /* nobody cared about this packet */
+ net_warn_ratelimited("%s: received unknown dispatch\n",
+ __func__);
+
+ /* fall-through */
+ case RX_DROP_UNUSABLE:
+ kfree_skb(skb);
- consume_skb(skb);
+ /* fall-through */
+ case RX_DROP:
+ return NET_RX_DROP;
+ case RX_QUEUED:
+ return lowpan_give_skb_to_device(skb);
+ default:
+ break;
+ }
- return stat;
+ return NET_RX_DROP;
}
-static int
-iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr)
+static inline bool lowpan_is_frag1(u8 dispatch)
{
- u8 iphc0, iphc1;
- struct ieee802154_addr_sa sa, da;
- void *sap, *dap;
+ return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAG1;
+}
- raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len);
- /* at least two bytes will be used for the encoding */
- if (skb->len < 2)
- return -EINVAL;
+static inline bool lowpan_is_fragn(u8 dispatch)
+{
+ return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAGN;
+}
- if (lowpan_fetch_skb_u8(skb, &iphc0))
- return -EINVAL;
+static lowpan_rx_result lowpan_rx_h_frag(struct sk_buff *skb)
+{
+ int ret;
- if (lowpan_fetch_skb_u8(skb, &iphc1))
- return -EINVAL;
+ if (!(lowpan_is_frag1(*skb_network_header(skb)) ||
+ lowpan_is_fragn(*skb_network_header(skb))))
+ return RX_CONTINUE;
- ieee802154_addr_to_sa(&sa, &hdr->source);
- ieee802154_addr_to_sa(&da, &hdr->dest);
+ ret = lowpan_frag_rcv(skb, *skb_network_header(skb) &
+ LOWPAN_DISPATCH_FRAG_MASK);
+ if (ret == 1)
+ return RX_QUEUED;
- if (sa.addr_type == IEEE802154_ADDR_SHORT)
- sap = &sa.short_addr;
- else
- sap = &sa.hwaddr;
+ /* Packet is freed by lowpan_frag_rcv on error or put into the frag
+ * bucket.
+ */
+ return RX_DROP;
+}
- if (da.addr_type == IEEE802154_ADDR_SHORT)
- dap = &da.short_addr;
- else
- dap = &da.hwaddr;
+int lowpan_iphc_decompress(struct sk_buff *skb)
+{
+ struct ieee802154_hdr hdr;
- return lowpan_header_decompress(skb, skb->dev, sap, sa.addr_type,
- IEEE802154_ADDR_LEN, dap, da.addr_type,
- IEEE802154_ADDR_LEN, iphc0, iphc1);
+ if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
+ return -EINVAL;
+
+ return lowpan_header_decompress(skb, skb->dev, &hdr.dest, &hdr.source);
}
-static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev,
- struct packet_type *pt, struct net_device *orig_dev)
+static lowpan_rx_result lowpan_rx_h_iphc(struct sk_buff *skb)
{
- struct ieee802154_hdr hdr;
int ret;
- skb = skb_share_check(skb, GFP_ATOMIC);
- if (!skb)
- goto drop;
+ if (!lowpan_is_iphc(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ /* Setting datagram_offset to zero indicates non frag handling
+ * while doing lowpan_header_decompress.
+ */
+ lowpan_802154_cb(skb)->d_size = 0;
- if (!netif_running(dev))
- goto drop_skb;
+ ret = lowpan_iphc_decompress(skb);
+ if (ret < 0)
+ return RX_DROP_UNUSABLE;
- if (skb->pkt_type == PACKET_OTHERHOST)
- goto drop_skb;
+ return RX_QUEUED;
+}
- if (dev->type != ARPHRD_IEEE802154)
- goto drop_skb;
+lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb)
+{
+ if (!lowpan_is_ipv6(*skb_network_header(skb)))
+ return RX_CONTINUE;
- if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0)
- goto drop_skb;
-
- /* check that it's our buffer */
- if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
- /* Pull off the 1-byte of 6lowpan header. */
- skb_pull(skb, 1);
- return lowpan_give_skb_to_devices(skb, NULL);
- } else {
- switch (skb->data[0] & 0xe0) {
- case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_devices(skb, NULL);
- case LOWPAN_DISPATCH_FRAG1: /* first fragment header */
- ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAG1);
- if (ret == 1) {
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_devices(skb, NULL);
- } else if (ret == -1) {
- return NET_RX_DROP;
- } else {
- return NET_RX_SUCCESS;
- }
- case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */
- ret = lowpan_frag_rcv(skb, LOWPAN_DISPATCH_FRAGN);
- if (ret == 1) {
- ret = iphc_decompress(skb, &hdr);
- if (ret < 0)
- goto drop_skb;
-
- return lowpan_give_skb_to_devices(skb, NULL);
- } else if (ret == -1) {
- return NET_RX_DROP;
- } else {
- return NET_RX_SUCCESS;
- }
- default:
- break;
- }
+ /* Pull off the 1-byte of 6lowpan header. */
+ skb_pull(skb, 1);
+ return RX_QUEUED;
+}
+
+static inline bool lowpan_is_esc(u8 dispatch)
+{
+ return dispatch == LOWPAN_DISPATCH_ESC;
+}
+
+static lowpan_rx_result lowpan_rx_h_esc(struct sk_buff *skb)
+{
+ if (!lowpan_is_esc(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ net_warn_ratelimited("%s: %s\n", skb->dev->name,
+ "6LoWPAN ESC not supported\n");
+
+ return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_hc1(u8 dispatch)
+{
+ return dispatch == LOWPAN_DISPATCH_HC1;
+}
+
+static lowpan_rx_result lowpan_rx_h_hc1(struct sk_buff *skb)
+{
+ if (!lowpan_is_hc1(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ net_warn_ratelimited("%s: %s\n", skb->dev->name,
+ "6LoWPAN HC1 not supported\n");
+
+ return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_dff(u8 dispatch)
+{
+ return dispatch == LOWPAN_DISPATCH_DFF;
+}
+
+static lowpan_rx_result lowpan_rx_h_dff(struct sk_buff *skb)
+{
+ if (!lowpan_is_dff(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ net_warn_ratelimited("%s: %s\n", skb->dev->name,
+ "6LoWPAN DFF not supported\n");
+
+ return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_bc0(u8 dispatch)
+{
+ return dispatch == LOWPAN_DISPATCH_BC0;
+}
+
+static lowpan_rx_result lowpan_rx_h_bc0(struct sk_buff *skb)
+{
+ if (!lowpan_is_bc0(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ net_warn_ratelimited("%s: %s\n", skb->dev->name,
+ "6LoWPAN BC0 not supported\n");
+
+ return RX_DROP_UNUSABLE;
+}
+
+static inline bool lowpan_is_mesh(u8 dispatch)
+{
+ return (dispatch & LOWPAN_DISPATCH_FIRST) == LOWPAN_DISPATCH_MESH;
+}
+
+static lowpan_rx_result lowpan_rx_h_mesh(struct sk_buff *skb)
+{
+ if (!lowpan_is_mesh(*skb_network_header(skb)))
+ return RX_CONTINUE;
+
+ net_warn_ratelimited("%s: %s\n", skb->dev->name,
+ "6LoWPAN MESH not supported\n");
+
+ return RX_DROP_UNUSABLE;
+}
+
+static int lowpan_invoke_rx_handlers(struct sk_buff *skb)
+{
+ lowpan_rx_result res;
+
+#define CALL_RXH(rxh) \
+ do { \
+ res = rxh(skb); \
+ if (res != RX_CONTINUE) \
+ goto rxh_next; \
+ } while (0)
+
+ /* likely at first */
+ CALL_RXH(lowpan_rx_h_iphc);
+ CALL_RXH(lowpan_rx_h_frag);
+ CALL_RXH(lowpan_rx_h_ipv6);
+ CALL_RXH(lowpan_rx_h_esc);
+ CALL_RXH(lowpan_rx_h_hc1);
+ CALL_RXH(lowpan_rx_h_dff);
+ CALL_RXH(lowpan_rx_h_bc0);
+ CALL_RXH(lowpan_rx_h_mesh);
+
+rxh_next:
+ return lowpan_rx_handlers_result(skb, res);
+#undef CALL_RXH
+}
+
+static inline bool lowpan_is_nalp(u8 dispatch)
+{
+ return (dispatch & LOWPAN_DISPATCH_FIRST) == LOWPAN_DISPATCH_NALP;
+}
+
+/* Lookup for reserved dispatch values at:
+ * https://www.iana.org/assignments/_6lowpan-parameters/_6lowpan-parameters.xhtml#_6lowpan-parameters-1
+ *
+ * Last Updated: 2015-01-22
+ */
+static inline bool lowpan_is_reserved(u8 dispatch)
+{
+ return ((dispatch >= 0x44 && dispatch <= 0x4F) ||
+ (dispatch >= 0x51 && dispatch <= 0x5F) ||
+ (dispatch >= 0xc8 && dispatch <= 0xdf) ||
+ (dispatch >= 0xe8 && dispatch <= 0xff));
+}
+
+/* lowpan_rx_h_check checks on generic 6LoWPAN requirements
+ * in MAC and 6LoWPAN header.
+ *
+ * Don't manipulate the skb here, it could be shared buffer.
+ */
+static inline bool lowpan_rx_h_check(struct sk_buff *skb)
+{
+ __le16 fc = ieee802154_get_fc_from_skb(skb);
+
+ /* check on ieee802154 conform 6LoWPAN header */
+ if (!ieee802154_is_data(fc) ||
+ !ieee802154_is_intra_pan(fc))
+ return false;
+
+ /* check if we can dereference the dispatch */
+ if (unlikely(!skb->len))
+ return false;
+
+ if (lowpan_is_nalp(*skb_network_header(skb)) ||
+ lowpan_is_reserved(*skb_network_header(skb)))
+ return false;
+
+ return true;
+}
+
+static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev,
+ struct packet_type *pt, struct net_device *orig_wdev)
+{
+ struct net_device *ldev;
+
+ if (wdev->type != ARPHRD_IEEE802154 ||
+ skb->pkt_type == PACKET_OTHERHOST ||
+ !lowpan_rx_h_check(skb))
+ goto drop;
+
+ ldev = wdev->ieee802154_ptr->lowpan_dev;
+ if (!ldev || !netif_running(ldev))
+ goto drop;
+
+ /* Replacing skb->dev and followed rx handlers will manipulate skb. */
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb)
+ goto out;
+ skb->dev = ldev;
+
+ /* When receive frag1 it's likely that we manipulate the buffer.
+ * When recevie iphc we manipulate the data buffer. So we need
+ * to unshare the buffer.
+ */
+ if (lowpan_is_frag1(*skb_network_header(skb)) ||
+ lowpan_is_iphc(*skb_network_header(skb))) {
+ skb = skb_unshare(skb, GFP_ATOMIC);
+ if (!skb)
+ goto out;
}
-drop_skb:
- kfree_skb(skb);
+ return lowpan_invoke_rx_handlers(skb);
+
drop:
+ kfree_skb(skb);
+out:
return NET_RX_DROP;
}
Code Review / kvmfornfv.git / blobdiff