/* This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <net/6lowpan.h> #include <net/ndisc.h> #include <net/ieee802154_netdev.h> #include <net/mac802154.h> #include "6lowpan_i.h" #define LOWPAN_FRAG1_HEAD_SIZE 0x4 #define LOWPAN_FRAGN_HEAD_SIZE 0x5 struct lowpan_addr_info { struct ieee802154_addr daddr; struct ieee802154_addr saddr; }; static inline struct lowpan_addr_info *lowpan_skb_priv(const struct sk_buff *skb) { WARN_ON_ONCE(skb_headroom(skb) < sizeof(struct lowpan_addr_info)); return (struct lowpan_addr_info *)(skb->data - sizeof(struct lowpan_addr_info)); } /* This callback will be called from AF_PACKET and IPv6 stack, the AF_PACKET * sockets gives an 8 byte array for addresses only! * * TODO I think AF_PACKET DGRAM (sending/receiving) RAW (sending) makes no * sense here. We should disable it, the right use-case would be AF_INET6 * RAW/DGRAM sockets. */ int lowpan_header_create(struct sk_buff *skb, struct net_device *ldev, unsigned short type, const void *daddr, const void *saddr, unsigned int len) { struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr; struct lowpan_addr_info *info = lowpan_skb_priv(skb); struct lowpan_802154_neigh *llneigh = NULL; const struct ipv6hdr *hdr = ipv6_hdr(skb); struct neighbour *n; /* TODO: * if this package isn't ipv6 one, where should it be routed? */ if (type != ETH_P_IPV6) return 0; /* intra-pan communication */ info->saddr.pan_id = wpan_dev->pan_id; info->daddr.pan_id = info->saddr.pan_id; if (!memcmp(daddr, ldev->broadcast, EUI64_ADDR_LEN)) { info->daddr.short_addr = cpu_to_le16(IEEE802154_ADDR_BROADCAST); info->daddr.mode = IEEE802154_ADDR_SHORT; } else { __le16 short_addr = cpu_to_le16(IEEE802154_ADDR_SHORT_UNSPEC); n = neigh_lookup(&nd_tbl, &hdr->daddr, ldev); if (n) { llneigh = lowpan_802154_neigh(neighbour_priv(n)); read_lock_bh(&n->lock); short_addr = llneigh->short_addr; read_unlock_bh(&n->lock); } if (llneigh && lowpan_802154_is_valid_src_short_addr(short_addr)) { info->daddr.short_addr = short_addr; info->daddr.mode = IEEE802154_ADDR_SHORT; } else { info->daddr.mode = IEEE802154_ADDR_LONG; ieee802154_be64_to_le64(&info->daddr.extended_addr, daddr); } if (n) neigh_release(n); } if (!saddr) { if (lowpan_802154_is_valid_src_short_addr(wpan_dev->short_addr)) { info->saddr.mode = IEEE802154_ADDR_SHORT; info->saddr.short_addr = wpan_dev->short_addr; } else { info->saddr.mode = IEEE802154_ADDR_LONG; info->saddr.extended_addr = wpan_dev->extended_addr; } } else { info->saddr.mode = IEEE802154_ADDR_LONG; ieee802154_be64_to_le64(&info->saddr.extended_addr, saddr); } return 0; } static struct sk_buff* lowpan_alloc_frag(struct sk_buff *skb, int size, const struct ieee802154_hdr *master_hdr, bool frag1) { struct net_device *wdev = lowpan_802154_dev(skb->dev)->wdev; struct sk_buff *frag; int rc; frag = alloc_skb(wdev->needed_headroom + wdev->needed_tailroom + size, GFP_ATOMIC); if (likely(frag)) { frag->dev = wdev; frag->priority = skb->priority; skb_reserve(frag, wdev->needed_headroom); skb_reset_network_header(frag); *mac_cb(frag) = *mac_cb(skb); if (frag1) { memcpy(skb_put(frag, skb->mac_len), skb_mac_header(skb), skb->mac_len); } else { rc = wpan_dev_hard_header(frag, wdev, &master_hdr->dest, &master_hdr->source, size); if (rc < 0) { kfree_skb(frag); return ERR_PTR(rc); } } } else { frag = ERR_PTR(-ENOMEM); } return frag; } static int lowpan_xmit_fragment(struct sk_buff *skb, const struct ieee802154_hdr *wpan_hdr, u8 *frag_hdr, int frag_hdrlen, int offset, int len, bool frag1) { struct sk_buff *frag; raw_dump_inline(__func__, " fragment header", frag_hdr, frag_hdrlen); frag = lowpan_alloc_frag(skb, frag_hdrlen + len, wpan_hdr, frag1); if (IS_ERR(frag)) return PTR_ERR(frag); memcpy(skb_put(frag, frag_hdrlen), frag_hdr, frag_hdrlen); memcpy(skb_put(frag, len), skb_network_header(skb) + offset, len); raw_dump_table(__func__, " fragment dump", frag->data, frag->len); return dev_queue_xmit(frag); } static int lowpan_xmit_fragmented(struct sk_buff *skb, struct net_device *ldev, const struct ieee802154_hdr *wpan_hdr, u16 dgram_size, u16 dgram_offset) { __be16 frag_tag; u8 frag_hdr[5]; int frag_cap, frag_len, payload_cap, rc; int skb_unprocessed, skb_offset; frag_tag = htons(lowpan_802154_dev(ldev)->fragment_tag); lowpan_802154_dev(ldev)->fragment_tag++; frag_hdr[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x07); frag_hdr[1] = dgram_size & 0xff; memcpy(frag_hdr + 2, &frag_tag, sizeof(frag_tag)); payload_cap = ieee802154_max_payload(wpan_hdr); frag_len = round_down(payload_cap - LOWPAN_FRAG1_HEAD_SIZE - skb_network_header_len(skb), 8); skb_offset = skb_network_header_len(skb); skb_unprocessed = skb->len - skb->mac_len - skb_offset; rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr, LOWPAN_FRAG1_HEAD_SIZE, 0, frag_len + skb_network_header_len(skb), true); if (rc) { pr_debug("%s unable to send FRAG1 packet (tag: %d)", __func__, ntohs(frag_tag)); goto err; } frag_hdr[0] &= ~LOWPAN_DISPATCH_FRAG1; frag_hdr[0] |= LOWPAN_DISPATCH_FRAGN; frag_cap = round_down(payload_cap - LOWPAN_FRAGN_HEAD_SIZE, 8); do { dgram_offset += frag_len; skb_offset += frag_len; skb_unprocessed -= frag_len; frag_len = min(frag_cap, skb_unprocessed); frag_hdr[4] = dgram_offset >> 3; rc = lowpan_xmit_fragment(skb, wpan_hdr, frag_hdr, LOWPAN_FRAGN_HEAD_SIZE, skb_offset, frag_len, false); if (rc) { pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n", __func__, ntohs(frag_tag), skb_offset); goto err; } } while (skb_unprocessed > frag_cap); ldev->stats.tx_packets++; ldev->stats.tx_bytes += dgram_size; consume_skb(skb); return NET_XMIT_SUCCESS; err: kfree_skb(skb); return rc; } static int lowpan_header(struct sk_buff *skb, struct net_device *ldev, u16 *dgram_size, u16 *dgram_offset) { struct wpan_dev *wpan_dev = lowpan_802154_dev(ldev)->wdev->ieee802154_ptr; struct ieee802154_mac_cb *cb = mac_cb_init(skb); struct lowpan_addr_info info; memcpy(&info, lowpan_skb_priv(skb), sizeof(info)); *dgram_size = skb->len; lowpan_header_compress(skb, ldev, &info.daddr, &info.saddr); /* dgram_offset = (saved bytes after compression) + lowpan header len */ *dgram_offset = (*dgram_size - skb->len) + skb_network_header_len(skb); cb->type = IEEE802154_FC_TYPE_DATA; if (info.daddr.mode == IEEE802154_ADDR_SHORT && ieee802154_is_broadcast_short_addr(info.daddr.short_addr)) cb->ackreq = false; else cb->ackreq = wpan_dev->ackreq; return wpan_dev_hard_header(skb, lowpan_802154_dev(ldev)->wdev, &info.daddr, &info.saddr, 0); } netdev_tx_t lowpan_xmit(struct sk_buff *skb, struct net_device *ldev) { struct ieee802154_hdr wpan_hdr; int max_single, ret; u16 dgram_size, dgram_offset; pr_debug("package xmit\n"); WARN_ON_ONCE(skb->len > IPV6_MIN_MTU); /* We must take a copy of the skb before we modify/replace the ipv6 * header as the header could be used elsewhere */ skb = skb_unshare(skb, GFP_ATOMIC); if (!skb) return NET_XMIT_DROP; ret = lowpan_header(skb, ldev, &dgram_size, &dgram_offset); if (ret < 0) { kfree_skb(skb); return NET_XMIT_DROP; } if (ieee802154_hdr_peek(skb, &wpan_hdr) < 0) { kfree_skb(skb); return NET_XMIT_DROP; } max_single = ieee802154_max_payload(&wpan_hdr); if (skb_tail_pointer(skb) - skb_network_header(skb) <= max_single) { skb->dev = lowpan_802154_dev(ldev)->wdev; ldev->stats.tx_packets++; ldev->stats.tx_bytes += dgram_size; return dev_queue_xmit(skb); } else { netdev_tx_t rc; pr_debug("frame is too big, fragmentation is needed\n"); rc = lowpan_xmit_fragmented(skb, ldev, &wpan_hdr, dgram_size, dgram_offset); return rc < 0 ? NET_XMIT_DROP : rc; } }