diff options
Diffstat (limited to 'net/ieee802154/6lowpan/rx.c')
| -rw-r--r-- | net/ieee802154/6lowpan/rx.c | 188 |
1 files changed, 127 insertions, 61 deletions
diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c index f9cb70b6749f..fded1099fae0 100644 --- a/net/ieee802154/6lowpan/rx.c +++ b/net/ieee802154/6lowpan/rx.c @@ -15,8 +15,9 @@ #include "6lowpan_i.h" -static int lowpan_give_skb_to_device(struct sk_buff *skb, - struct net_device *wdev) +#define LOWPAN_DISPATCH_FRAG_MASK 0xf8 + +static int lowpan_give_skb_to_device(struct sk_buff *skb) { skb->protocol = htons(ETH_P_IPV6); skb->pkt_type = PACKET_HOST; @@ -24,21 +25,77 @@ static int lowpan_give_skb_to_device(struct sk_buff *skb, return netif_rx(skb); } -static int -iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr) +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); + + /* fall-through */ + case RX_DROP: + return NET_RX_DROP; + case RX_QUEUED: + return lowpan_give_skb_to_device(skb); + default: + break; + } + + return NET_RX_DROP; +} + +static inline bool lowpan_is_frag1(u8 dispatch) +{ + return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAG1; +} + +static inline bool lowpan_is_fragn(u8 dispatch) +{ + return (dispatch & LOWPAN_DISPATCH_FRAG_MASK) == LOWPAN_DISPATCH_FRAGN; +} + +static lowpan_rx_result lowpan_rx_h_frag(struct sk_buff *skb) +{ + int ret; + + if (!(lowpan_is_frag1(*skb_network_header(skb)) || + lowpan_is_fragn(*skb_network_header(skb)))) + return RX_CONTINUE; + + ret = lowpan_frag_rcv(skb, *skb_network_header(skb) & + LOWPAN_DISPATCH_FRAG_MASK); + if (ret == 1) + return RX_QUEUED; + + /* Packet is freed by lowpan_frag_rcv on error or put into the frag + * bucket. + */ + return RX_DROP; +} + +int lowpan_iphc_decompress(struct sk_buff *skb) { - u8 iphc0, iphc1; struct ieee802154_addr_sa sa, da; + struct ieee802154_hdr hdr; + u8 iphc0, iphc1; void *sap, *dap; + if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) + return -EINVAL; + raw_dump_table(__func__, "raw skb data dump", skb->data, skb->len); if (lowpan_fetch_skb_u8(skb, &iphc0) || lowpan_fetch_skb_u8(skb, &iphc1)) return -EINVAL; - ieee802154_addr_to_sa(&sa, &hdr->source); - ieee802154_addr_to_sa(&da, &hdr->dest); + ieee802154_addr_to_sa(&sa, &hdr.source); + ieee802154_addr_to_sa(&da, &hdr.dest); if (sa.addr_type == IEEE802154_ADDR_SHORT) sap = &sa.short_addr; @@ -55,78 +112,87 @@ iphc_decompress(struct sk_buff *skb, const struct ieee802154_hdr *hdr) IEEE802154_ADDR_LEN, iphc0, iphc1); } +static lowpan_rx_result lowpan_rx_h_iphc(struct sk_buff *skb) +{ + int ret; + + 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; + + ret = lowpan_iphc_decompress(skb); + if (ret < 0) + return RX_DROP_UNUSABLE; + + return RX_QUEUED; +} + +lowpan_rx_result lowpan_rx_h_ipv6(struct sk_buff *skb) +{ + if (!lowpan_is_ipv6(*skb_network_header(skb))) + return RX_CONTINUE; + + /* Pull off the 1-byte of 6lowpan header. */ + skb_pull(skb, 1); + return RX_QUEUED; +} + +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); + +rxh_next: + return lowpan_rx_handlers_result(skb, res); +#undef CALL_RXH +} + static int lowpan_rcv(struct sk_buff *skb, struct net_device *wdev, struct packet_type *pt, struct net_device *orig_wdev) { - struct ieee802154_hdr hdr; struct net_device *ldev; - int ret; if (wdev->type != ARPHRD_IEEE802154 || skb->pkt_type == PACKET_OTHERHOST) - goto drop; + return NET_RX_DROP; ldev = wdev->ieee802154_ptr->lowpan_dev; if (!ldev || !netif_running(ldev)) - goto drop; + return NET_RX_DROP; /* Replacing skb->dev and followed rx handlers will manipulate skb. */ skb = skb_share_check(skb, GFP_ATOMIC); if (!skb) - goto drop; + return NET_RX_DROP; skb->dev = ldev; - 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_device(skb, wdev); - } 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_device(skb, wdev); - 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_device(skb, wdev); - } 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_device(skb, wdev); - } else if (ret == -1) { - return NET_RX_DROP; - } else { - return NET_RX_SUCCESS; - } - default: - break; - } + /* 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) + return RX_DROP; } -drop_skb: - kfree_skb(skb); -drop: - return NET_RX_DROP; + return lowpan_invoke_rx_handlers(skb); } static struct packet_type lowpan_packet_type = { |