X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fnet%2Fieee802154%2F6lowpan%2Frx.c;fp=kernel%2Fnet%2Fieee802154%2F6lowpan%2Frx.c;h=ef185dd4110d74e44139e96dd6fdeec26aafb5fd;hb=e09b41010ba33a20a87472ee821fa407a5b8da36;hp=4be1d289ab2df7581d93702d46bf3793abeba1a7;hpb=f93b97fd65072de626c074dbe099a1fff05ce060;p=kvmfornfv.git diff --git a/kernel/net/ieee802154/6lowpan/rx.c b/kernel/net/ieee802154/6lowpan/rx.c index 4be1d289a..ef185dd41 100644 --- a/kernel/net/ieee802154/6lowpan/rx.c +++ b/kernel/net/ieee802154/6lowpan/rx.c @@ -11,147 +11,307 @@ #include #include +#include #include #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; }