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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /net/ieee802154/6lowpan/rx.c | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ieee802154/6lowpan/rx.c')
-rw-r--r-- | net/ieee802154/6lowpan/rx.c | 323 |
1 files changed, 323 insertions, 0 deletions
diff --git a/net/ieee802154/6lowpan/rx.c b/net/ieee802154/6lowpan/rx.c new file mode 100644 index 0000000000..517e6493f5 --- /dev/null +++ b/net/ieee802154/6lowpan/rx.c @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#include <linux/if_arp.h> + +#include <net/6lowpan.h> +#include <net/mac802154.h> +#include <net/ieee802154_netdev.h> + +#include "6lowpan_i.h" + +#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->dev->stats.rx_packets++; + skb->dev->stats.rx_bytes += skb->len; + + return netif_rx(skb); +} + +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__); + + fallthrough; + case RX_DROP_UNUSABLE: + kfree_skb(skb); + + fallthrough; + 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) +{ + struct ieee802154_hdr hdr; + + if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) + return -EINVAL; + + return lowpan_header_decompress(skb, skb->dev, &hdr.dest, &hdr.source); +} + +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 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); +} + +/* 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_skb_is_intra_pan_addressing(fc, skb)) + 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; + } + + return lowpan_invoke_rx_handlers(skb); + +drop: + kfree_skb(skb); +out: + return NET_RX_DROP; +} + +static struct packet_type lowpan_packet_type = { + .type = htons(ETH_P_IEEE802154), + .func = lowpan_rcv, +}; + +void lowpan_rx_init(void) +{ + dev_add_pack(&lowpan_packet_type); +} + +void lowpan_rx_exit(void) +{ + dev_remove_pack(&lowpan_packet_type); +} |