Return-Path: Subject: Re: [PATCH 5/5] 6lowpan: Use netdev addr_len to determine lladdr len To: Luiz Augusto von Dentz References: <20170209145551.12747-1-luiz.dentz@gmail.com> <20170209145551.12747-6-luiz.dentz@gmail.com> Cc: linux-bluetooth@vger.kernel.org, patrik.flykt@linux.intel.com From: Alexander Aring Message-ID: <7f9a9a39-fbe4-c577-3b8b-e8350634ddcb@pengutronix.de> Date: Wed, 15 Feb 2017 08:44:19 +0100 MIME-Version: 1.0 In-Reply-To: <20170209145551.12747-6-luiz.dentz@gmail.com> Content-Type: text/plain; charset=windows-1252 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi, On 02/09/2017 03:55 PM, Luiz Augusto von Dentz wrote: > From: Luiz Augusto von Dentz > > This allow technologies such as Bluetooth to use its native lladdr which > is eui48 instead of eui64 which was expected by functions like > lowpan_header_decompress and lowpan_header_compress. > > Signed-off-by: Luiz Augusto von Dentz > --- > net/6lowpan/iphc.c | 17 +++++++++++++++-- > net/bluetooth/6lowpan.c | 43 ++++++++++--------------------------------- > 2 files changed, 25 insertions(+), 35 deletions(-) > > diff --git a/net/6lowpan/iphc.c b/net/6lowpan/iphc.c > index fb5f6fa..ee88feb 100644 > --- a/net/6lowpan/iphc.c > +++ b/net/6lowpan/iphc.c > @@ -827,8 +827,21 @@ static u8 lowpan_compress_ctx_addr(u8 **hc_ptr, const struct net_device *dev, > } > break; > default: > - /* check for SAM/DAM = 11 */ > - memcpy(&tmp.s6_addr[8], lladdr, EUI64_ADDR_LEN); > + switch (dev->addr_len) { > + case ETH_ALEN: > + memcpy(&tmp.s6_addr[8], lladdr, 3); > + tmp.s6_addr[11] = 0xFF; > + tmp.s6_addr[12] = 0xFE; > + memcpy(&tmp.s6_addr[13], lladdr + 3, 3); > + break; > + case EUI64_ADDR_LEN: > + memcpy(&tmp.s6_addr[8], lladdr, EUI64_ADDR_LEN); > + break; > + default: > + dam = LOWPAN_IPHC_DAM_11; > + goto out; > + } > + > /* second bit-flip (Universe/Local) is done according RFC2464 */ > tmp.s6_addr[8] ^= 0x02; move this handling in per link-layer layer decision, see below. > /* context information are always used */ PLEASE... and this is one of my rant! PLEASE LOOK WHAT I HAVE DONE IN THIS FILE IN MY RFC PATCH SERIES YOU NEED TO FIX MORE THAN JUST CONTEXT BASED COMPRESSION. e.g. stateless un/compression Now I for this, I want to see a link-layer evaluation not address length based. Please do so also for the other patch which fixing some behaviour in ipv6. The reason is here that uncompress/compress addresses are defined by RFC 6LoWPAN adapation. There is already a link-layer case, so please add BTLE LLTYPE there! Not move your handling in default, add some WARN_ONCE there... btw: here exists also a cleanup to not always implement the same stuff. We need for stateful/stateless compression one function, because and remember my words if you want to make this cleanup: Stateless compression is stateful compression with prefix fe80::/64 as context. --- Sorry for my rant, but I am somehow pissed off because intel people doesn't look what I did there in my RFC. ... I think now I know why linux kernel people do sometimes a rant. :-) Thanks. > diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c > index 1456b01..d2a1aa5 100644 > --- a/net/bluetooth/6lowpan.c > +++ b/net/bluetooth/6lowpan.c > @@ -64,7 +64,7 @@ struct lowpan_peer { > struct l2cap_chan *chan; > > /* peer addresses in various formats */ > - unsigned char eui64_addr[EUI64_ADDR_LEN]; > + unsigned char lladdr[ETH_ALEN]; > struct in6_addr peer_addr; > }; > > @@ -80,8 +80,6 @@ struct lowpan_btle_dev { > struct delayed_work notify_peers; > }; > > -static void set_addr(u8 *eui, u8 *addr, u8 addr_type); > - > static inline struct lowpan_btle_dev * > lowpan_btle_dev(const struct net_device *netdev) > { > @@ -277,7 +275,6 @@ static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, > const u8 *saddr; > struct lowpan_btle_dev *dev; > struct lowpan_peer *peer; > - unsigned char eui64_daddr[EUI64_ADDR_LEN]; > > dev = lowpan_btle_dev(netdev); > > @@ -287,10 +284,9 @@ static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, > if (!peer) > return -EINVAL; > > - saddr = peer->eui64_addr; > - set_addr(&eui64_daddr[0], chan->src.b, chan->src_type); > + saddr = peer->lladdr; > > - return lowpan_header_decompress(skb, netdev, &eui64_daddr, saddr); > + return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); This looks not right, you are sure that netdev->dev_addr is the _destination_ address? It looks very confusing, because dev_addr is normally the source address of the netdevice interface. > } > > static int recv_pkt(struct sk_buff *skb, struct net_device *dev, > @@ -477,7 +473,7 @@ static int setup_header(struct sk_buff *skb, struct net_device *netdev, > } > } > > - daddr = peer->eui64_addr; > + daddr = peer->lladdr; > *peer_addr = addr; > *peer_addr_type = addr_type; > lowpan_cb(skb)->chan = peer->chan; > @@ -663,27 +659,6 @@ static struct device_type bt_type = { > .name = "bluetooth", > }; > > -static void set_addr(u8 *eui, u8 *addr, u8 addr_type) > -{ > - /* addr is the BT address in little-endian format */ > - eui[0] = addr[5]; > - eui[1] = addr[4]; > - eui[2] = addr[3]; > - eui[3] = 0xFF; > - eui[4] = 0xFE; > - eui[5] = addr[2]; > - eui[6] = addr[1]; > - eui[7] = addr[0]; > - > - /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */ > - if (addr_type == BDADDR_LE_PUBLIC) > - eui[0] &= ~0x02; > - else > - eui[0] |= 0x02; > - > - BT_DBG("type %d addr %*phC", addr_type, 8, eui); > -} > - YAY, this function is totally wrong! :-) > static void ifup(struct net_device *netdev) > { > int err; > @@ -762,14 +737,16 @@ static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, > peer->chan = chan; > memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); > > + baswap((void *)peer->lladdr, &chan->dst); > + > /* RFC 2464 ch. 5 */ > peer->peer_addr.s6_addr[0] = 0xFE; > peer->peer_addr.s6_addr[1] = 0x80; > - set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b, > - chan->dst_type); > > - memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8, > - EUI64_ADDR_LEN); > + memcpy(&peer->peer_addr.s6_addr[8], peer->lladdr, 3); > + peer->peer_addr.s6_addr[11] = 0xFF; > + peer->peer_addr.s6_addr[12] = 0xFE; > + memcpy(&peer->peer_addr.s6_addr[13], peer->lladdr + 3, 3); > What the hell is that? I suppose this is to handling something correct to a behaviour which is another big thing which is totally broken in the BTLE 6LoWPAN code. > /* IPv6 address needs to have the U/L bit set properly so toggle > * it back here. > - Alex