From b4b7ff4b08e691656c9d77c758fc355833128ac0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 20 Jan 2016 14:01:31 -0300 Subject: Linux-libre 4.4-gnu --- net/ieee802154/6lowpan/reassembly.c | 168 ++++++++++++++++++++++++------------ 1 file changed, 115 insertions(+), 53 deletions(-) (limited to 'net/ieee802154/6lowpan/reassembly.c') diff --git a/net/ieee802154/6lowpan/reassembly.c b/net/ieee802154/6lowpan/reassembly.c index 214d44aef..6b437e876 100644 --- a/net/ieee802154/6lowpan/reassembly.c +++ b/net/ieee802154/6lowpan/reassembly.c @@ -32,21 +32,10 @@ static const char lowpan_frags_cache_name[] = "lowpan-frags"; -struct lowpan_frag_info { - u16 d_tag; - u16 d_size; - u8 d_offset; -}; - -static struct lowpan_frag_info *lowpan_cb(struct sk_buff *skb) -{ - return (struct lowpan_frag_info *)skb->cb; -} - static struct inet_frags lowpan_frags; static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, - struct sk_buff *prev, struct net_device *dev); + struct sk_buff *prev, struct net_device *ldev); static unsigned int lowpan_hash_frag(u16 tag, u16 d_size, const struct ieee802154_addr *saddr, @@ -111,7 +100,7 @@ out: } static inline struct lowpan_frag_queue * -fq_find(struct net *net, const struct lowpan_frag_info *frag_info, +fq_find(struct net *net, const struct lowpan_802154_cb *cb, const struct ieee802154_addr *src, const struct ieee802154_addr *dst) { @@ -121,12 +110,12 @@ fq_find(struct net *net, const struct lowpan_frag_info *frag_info, struct netns_ieee802154_lowpan *ieee802154_lowpan = net_ieee802154_lowpan(net); - arg.tag = frag_info->d_tag; - arg.d_size = frag_info->d_size; + arg.tag = cb->d_tag; + arg.d_size = cb->d_size; arg.src = src; arg.dst = dst; - hash = lowpan_hash_frag(frag_info->d_tag, frag_info->d_size, src, dst); + hash = lowpan_hash_frag(cb->d_tag, cb->d_size, src, dst); q = inet_frag_find(&ieee802154_lowpan->frags, &lowpan_frags, &arg, hash); @@ -138,17 +127,17 @@ fq_find(struct net *net, const struct lowpan_frag_info *frag_info, } static int lowpan_frag_queue(struct lowpan_frag_queue *fq, - struct sk_buff *skb, const u8 frag_type) + struct sk_buff *skb, u8 frag_type) { struct sk_buff *prev, *next; - struct net_device *dev; + struct net_device *ldev; int end, offset; if (fq->q.flags & INET_FRAG_COMPLETE) goto err; - offset = lowpan_cb(skb)->d_offset << 3; - end = lowpan_cb(skb)->d_size; + offset = lowpan_802154_cb(skb)->d_offset << 3; + end = lowpan_802154_cb(skb)->d_size; /* Is this the final fragment? */ if (offset + skb->len == end) { @@ -174,13 +163,16 @@ static int lowpan_frag_queue(struct lowpan_frag_queue *fq, * this fragment, right? */ prev = fq->q.fragments_tail; - if (!prev || lowpan_cb(prev)->d_offset < lowpan_cb(skb)->d_offset) { + if (!prev || + lowpan_802154_cb(prev)->d_offset < + lowpan_802154_cb(skb)->d_offset) { next = NULL; goto found; } prev = NULL; for (next = fq->q.fragments; next != NULL; next = next->next) { - if (lowpan_cb(next)->d_offset >= lowpan_cb(skb)->d_offset) + if (lowpan_802154_cb(next)->d_offset >= + lowpan_802154_cb(skb)->d_offset) break; /* bingo! */ prev = next; } @@ -195,18 +187,15 @@ found: else fq->q.fragments = skb; - dev = skb->dev; - if (dev) + ldev = skb->dev; + if (ldev) skb->dev = NULL; fq->q.stamp = skb->tstamp; - if (frag_type == LOWPAN_DISPATCH_FRAG1) { - /* Calculate uncomp. 6lowpan header to estimate full size */ - fq->q.meat += lowpan_uncompress_size(skb, NULL); + if (frag_type == LOWPAN_DISPATCH_FRAG1) fq->q.flags |= INET_FRAG_FIRST_IN; - } else { - fq->q.meat += skb->len; - } + + fq->q.meat += skb->len; add_frag_mem_limit(fq->q.net, skb->truesize); if (fq->q.flags == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && @@ -215,7 +204,7 @@ found: unsigned long orefdst = skb->_skb_refdst; skb->_skb_refdst = 0UL; - res = lowpan_frag_reasm(fq, prev, dev); + res = lowpan_frag_reasm(fq, prev, ldev); skb->_skb_refdst = orefdst; return res; } @@ -235,7 +224,7 @@ err: * the last and the first frames arrived and all the bits are here. */ static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *prev, - struct net_device *dev) + struct net_device *ldev) { struct sk_buff *fp, *head = fq->q.fragments; int sum_truesize; @@ -313,7 +302,7 @@ static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, struct sk_buff *prev, sub_frag_mem_limit(fq->q.net, sum_truesize); head->next = NULL; - head->dev = dev; + head->dev = ldev; head->tstamp = fq->q.stamp; fq->q.fragments = NULL; @@ -325,24 +314,87 @@ out_oom: return -1; } -static int lowpan_get_frag_info(struct sk_buff *skb, const u8 frag_type, - struct lowpan_frag_info *frag_info) +static int lowpan_frag_rx_handlers_result(struct sk_buff *skb, + lowpan_rx_result res) +{ + switch (res) { + case RX_QUEUED: + return NET_RX_SUCCESS; + case RX_CONTINUE: + /* nobody cared about this packet */ + net_warn_ratelimited("%s: received unknown dispatch\n", + __func__); + + /* fall-through */ + default: + /* all others failure */ + return NET_RX_DROP; + } +} + +static lowpan_rx_result lowpan_frag_rx_h_iphc(struct sk_buff *skb) +{ + int ret; + + if (!lowpan_is_iphc(*skb_network_header(skb))) + return RX_CONTINUE; + + ret = lowpan_iphc_decompress(skb); + if (ret < 0) + return RX_DROP; + + return RX_QUEUED; +} + +static int lowpan_invoke_frag_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_frag_rx_h_iphc); + CALL_RXH(lowpan_rx_h_ipv6); + +rxh_next: + return lowpan_frag_rx_handlers_result(skb, res); +#undef CALL_RXH +} + +#define LOWPAN_FRAG_DGRAM_SIZE_HIGH_MASK 0x07 +#define LOWPAN_FRAG_DGRAM_SIZE_HIGH_SHIFT 8 + +static int lowpan_get_cb(struct sk_buff *skb, u8 frag_type, + struct lowpan_802154_cb *cb) { bool fail; - u8 pattern = 0, low = 0; + u8 high = 0, low = 0; __be16 d_tag = 0; - fail = lowpan_fetch_skb(skb, &pattern, 1); + fail = lowpan_fetch_skb(skb, &high, 1); fail |= lowpan_fetch_skb(skb, &low, 1); - frag_info->d_size = (pattern & 7) << 8 | low; + /* remove the dispatch value and use first three bits as high value + * for the datagram size + */ + cb->d_size = (high & LOWPAN_FRAG_DGRAM_SIZE_HIGH_MASK) << + LOWPAN_FRAG_DGRAM_SIZE_HIGH_SHIFT | low; fail |= lowpan_fetch_skb(skb, &d_tag, 2); - frag_info->d_tag = ntohs(d_tag); + cb->d_tag = ntohs(d_tag); if (frag_type == LOWPAN_DISPATCH_FRAGN) { - fail |= lowpan_fetch_skb(skb, &frag_info->d_offset, 1); + fail |= lowpan_fetch_skb(skb, &cb->d_offset, 1); } else { skb_reset_network_header(skb); - frag_info->d_offset = 0; + cb->d_offset = 0; + /* check if datagram_size has ipv6hdr on FRAG1 */ + fail |= cb->d_size < sizeof(struct ipv6hdr); + /* check if we can dereference the dispatch value */ + fail |= !skb->len; } if (unlikely(fail)) @@ -351,27 +403,33 @@ static int lowpan_get_frag_info(struct sk_buff *skb, const u8 frag_type, return 0; } -int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type) +int lowpan_frag_rcv(struct sk_buff *skb, u8 frag_type) { struct lowpan_frag_queue *fq; struct net *net = dev_net(skb->dev); - struct lowpan_frag_info *frag_info = lowpan_cb(skb); - struct ieee802154_addr source, dest; + struct lowpan_802154_cb *cb = lowpan_802154_cb(skb); + struct ieee802154_hdr hdr; int err; - source = mac_cb(skb)->source; - dest = mac_cb(skb)->dest; + if (ieee802154_hdr_peek_addrs(skb, &hdr) < 0) + goto err; - err = lowpan_get_frag_info(skb, frag_type, frag_info); + err = lowpan_get_cb(skb, frag_type, cb); if (err < 0) goto err; - if (frag_info->d_size > IPV6_MIN_MTU) { + if (frag_type == LOWPAN_DISPATCH_FRAG1) { + err = lowpan_invoke_frag_rx_handlers(skb); + if (err == NET_RX_DROP) + goto err; + } + + if (cb->d_size > IPV6_MIN_MTU) { net_warn_ratelimited("lowpan_frag_rcv: datagram size exceeds MTU\n"); goto err; } - fq = fq_find(net, frag_info, &source, &dest); + fq = fq_find(net, cb, &hdr.source, &hdr.dest); if (fq != NULL) { int ret; @@ -387,7 +445,6 @@ err: kfree_skb(skb); return -1; } -EXPORT_SYMBOL(lowpan_frag_rcv); #ifdef CONFIG_SYSCTL static int zero; @@ -523,14 +580,19 @@ static int __net_init lowpan_frags_init_net(struct net *net) { struct netns_ieee802154_lowpan *ieee802154_lowpan = net_ieee802154_lowpan(net); + int res; ieee802154_lowpan->frags.high_thresh = IPV6_FRAG_HIGH_THRESH; ieee802154_lowpan->frags.low_thresh = IPV6_FRAG_LOW_THRESH; ieee802154_lowpan->frags.timeout = IPV6_FRAG_TIMEOUT; - inet_frags_init_net(&ieee802154_lowpan->frags); - - return lowpan_frags_ns_sysctl_register(net); + res = inet_frags_init_net(&ieee802154_lowpan->frags); + if (res) + return res; + res = lowpan_frags_ns_sysctl_register(net); + if (res) + inet_frags_uninit_net(&ieee802154_lowpan->frags); + return res; } static void __net_exit lowpan_frags_exit_net(struct net *net) -- cgit v1.2.3-54-g00ecf