diff options
| -rw-r--r-- | include/net/ieee802154_netdev.h | 7 | ||||
| -rw-r--r-- | include/net/net_namespace.h | 4 | ||||
| -rw-r--r-- | include/net/netns/ieee802154_6lowpan.h | 22 | ||||
| -rw-r--r-- | net/ieee802154/6lowpan.h | 113 | ||||
| -rw-r--r-- | net/ieee802154/6lowpan_rtnl.c (renamed from net/ieee802154/6lowpan.c) | 323 | ||||
| -rw-r--r-- | net/ieee802154/Makefile | 1 | ||||
| -rw-r--r-- | net/ieee802154/reassembly.c | 564 | ||||
| -rw-r--r-- | net/ieee802154/reassembly.h | 66 |
8 files changed, 864 insertions, 236 deletions
diff --git a/include/net/ieee802154_netdev.h b/include/net/ieee802154_netdev.h index 8196d5d40359..97b2e34d87f7 100644 --- a/include/net/ieee802154_netdev.h +++ b/include/net/ieee802154_netdev.h @@ -29,6 +29,12 @@ #include <net/af_ieee802154.h> +struct ieee802154_frag_info { + __be16 d_tag; + u16 d_size; + u8 d_offset; +}; + /* * A control block of skb passed between the ARPHRD_IEEE802154 device * and other stack parts. @@ -39,6 +45,7 @@ struct ieee802154_mac_cb { struct ieee802154_addr da; u8 flags; u8 seq; + struct ieee802154_frag_info frag_info; }; static inline struct ieee802154_mac_cb *mac_cb(struct sk_buff *skb) diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index 991dcd94cbbf..79387f73f875 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -15,6 +15,7 @@ #include <net/netns/packet.h> #include <net/netns/ipv4.h> #include <net/netns/ipv6.h> +#include <net/netns/ieee802154_6lowpan.h> #include <net/netns/sctp.h> #include <net/netns/dccp.h> #include <net/netns/netfilter.h> @@ -90,6 +91,9 @@ struct net { #if IS_ENABLED(CONFIG_IPV6) struct netns_ipv6 ipv6; #endif +#if IS_ENABLED(CONFIG_IEEE802154_6LOWPAN) + struct netns_ieee802154_lowpan ieee802154_lowpan; +#endif #if defined(CONFIG_IP_SCTP) || defined(CONFIG_IP_SCTP_MODULE) struct netns_sctp sctp; #endif diff --git a/include/net/netns/ieee802154_6lowpan.h b/include/net/netns/ieee802154_6lowpan.h new file mode 100644 index 000000000000..079030c853d8 --- /dev/null +++ b/include/net/netns/ieee802154_6lowpan.h @@ -0,0 +1,22 @@ +/* + * ieee802154 6lowpan in net namespaces + */ + +#include <net/inet_frag.h> + +#ifndef __NETNS_IEEE802154_6LOWPAN_H__ +#define __NETNS_IEEE802154_6LOWPAN_H__ + +struct netns_sysctl_lowpan { +#ifdef CONFIG_SYSCTL + struct ctl_table_header *frags_hdr; +#endif +}; + +struct netns_ieee802154_lowpan { + struct netns_sysctl_lowpan sysctl; + struct netns_frags frags; + u16 max_dsize; +}; + +#endif diff --git a/net/ieee802154/6lowpan.h b/net/ieee802154/6lowpan.h index 2b835db3bda8..0dccf62434d5 100644 --- a/net/ieee802154/6lowpan.h +++ b/net/ieee802154/6lowpan.h @@ -306,6 +306,119 @@ static inline void lowpan_push_hc_data(u8 **hc_ptr, const void *data, *hc_ptr += len; } +static inline u8 lowpan_addr_mode_size(const u8 addr_mode) +{ + static const u8 addr_sizes[] = { + [LOWPAN_IPHC_ADDR_00] = 16, + [LOWPAN_IPHC_ADDR_01] = 8, + [LOWPAN_IPHC_ADDR_02] = 2, + [LOWPAN_IPHC_ADDR_03] = 0, + }; + return addr_sizes[addr_mode]; +} + +static inline u8 lowpan_next_hdr_size(const u8 h_enc, u16 *uncomp_header) +{ + u8 ret = 1; + + if ((h_enc & LOWPAN_NHC_UDP_MASK) == LOWPAN_NHC_UDP_ID) { + *uncomp_header += sizeof(struct udphdr); + + switch (h_enc & LOWPAN_NHC_UDP_CS_P_11) { + case LOWPAN_NHC_UDP_CS_P_00: + ret += 4; + break; + case LOWPAN_NHC_UDP_CS_P_01: + case LOWPAN_NHC_UDP_CS_P_10: + ret += 3; + break; + case LOWPAN_NHC_UDP_CS_P_11: + ret++; + break; + default: + break; + } + + if (!(h_enc & LOWPAN_NHC_UDP_CS_C)) + ret += 2; + } + + return ret; +} + +/** + * lowpan_uncompress_size - returns skb->len size with uncompressed header + * @skb: sk_buff with 6lowpan header inside + * @datagram_offset: optional to get the datagram_offset value + * + * Returns the skb->len with uncompressed header + */ +static inline u16 +lowpan_uncompress_size(const struct sk_buff *skb, u16 *dgram_offset) +{ + u16 ret = 2, uncomp_header = sizeof(struct ipv6hdr); + u8 iphc0, iphc1, h_enc; + + iphc0 = skb_network_header(skb)[0]; + iphc1 = skb_network_header(skb)[1]; + + switch ((iphc0 & LOWPAN_IPHC_TF) >> 3) { + case 0: + ret += 4; + break; + case 1: + ret += 3; + break; + case 2: + ret++; + break; + default: + break; + } + + if (!(iphc0 & LOWPAN_IPHC_NH_C)) + ret++; + + if (!(iphc0 & 0x03)) + ret++; + + ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_SAM) >> + LOWPAN_IPHC_SAM_BIT); + + if (iphc1 & LOWPAN_IPHC_M) { + switch ((iphc1 & LOWPAN_IPHC_DAM_11) >> + LOWPAN_IPHC_DAM_BIT) { + case LOWPAN_IPHC_DAM_00: + ret += 16; + break; + case LOWPAN_IPHC_DAM_01: + ret += 6; + break; + case LOWPAN_IPHC_DAM_10: + ret += 4; + break; + case LOWPAN_IPHC_DAM_11: + ret++; + break; + default: + break; + } + } else { + ret += lowpan_addr_mode_size((iphc1 & LOWPAN_IPHC_DAM_11) >> + LOWPAN_IPHC_DAM_BIT); + } + + if (iphc0 & LOWPAN_IPHC_NH_C) { + h_enc = skb_network_header(skb)[ret]; + ret += lowpan_next_hdr_size(h_enc, &uncomp_header); + } + + if (dgram_offset) + *dgram_offset = uncomp_header; + + return skb->len + uncomp_header - ret; +} + typedef int (*skb_delivery_cb)(struct sk_buff *skb, struct net_device *dev); int lowpan_process_data(struct sk_buff *skb, struct net_device *dev, diff --git a/net/ieee802154/6lowpan.c b/net/ieee802154/6lowpan_rtnl.c index 8edfea5da572..c7bd8b55f7ce 100644 --- a/net/ieee802154/6lowpan.c +++ b/net/ieee802154/6lowpan_rtnl.c @@ -1,10 +1,8 @@ -/* - * Copyright 2011, Siemens AG +/* Copyright 2011, Siemens AG * written by Alexander Smirnov <alex.bluesman.smirnov@gmail.com> */ -/* - * Based on patches from Jon Smirl <jonsmirl@gmail.com> +/* Based on patches from Jon Smirl <jonsmirl@gmail.com> * Copyright (c) 2011 Jon Smirl <jonsmirl@gmail.com> * * This program is free software; you can redistribute it and/or modify @@ -15,10 +13,6 @@ * 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. - * - * You should have received a copy of the GNU General Public License along - * with this program; if not, write to the Free Software Foundation, Inc., - * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ /* Jon's code is based on 6lowpan implementation for Contiki which is: @@ -60,6 +54,7 @@ #include <net/ieee802154_netdev.h> #include <net/ipv6.h> +#include "reassembly.h" #include "6lowpan.h" static LIST_HEAD(lowpan_devices); @@ -68,7 +63,7 @@ static LIST_HEAD(lowpan_devices); struct lowpan_dev_info { struct net_device *real_dev; /* real WPAN device ptr */ struct mutex dev_list_mtx; /* mutex for list ops */ - unsigned short fragment_tag; + __be16 fragment_tag; }; struct lowpan_dev_record { @@ -76,18 +71,6 @@ struct lowpan_dev_record { struct list_head list; }; -struct lowpan_fragment { - struct sk_buff *skb; /* skb to be assembled */ - u16 length; /* length to be assemled */ - u32 bytes_rcv; /* bytes received */ - u16 tag; /* current fragment tag */ - struct timer_list timer; /* assembling timer */ - struct list_head list; /* fragments list */ -}; - -static LIST_HEAD(lowpan_fragments); -static DEFINE_SPINLOCK(flist_lock); - static inline struct lowpan_dev_info *lowpan_dev_info(const struct net_device *dev) { @@ -124,13 +107,11 @@ static int lowpan_header_create(struct sk_buff *skb, lowpan_header_compress(skb, dev, type, daddr, saddr, len); - /* - * NOTE1: I'm still unsure about the fact that compression and WPAN + /* NOTE1: I'm still unsure about the fact that compression and WPAN * header are created here and not later in the xmit. So wait for * an opinion of net maintainers. */ - /* - * NOTE2: to be absolutely correct, we must derive PANid information + /* NOTE2: to be absolutely correct, we must derive PANid information * from MAC subif of the 'dev' and 'real_dev' network devices, but * this isn't implemented in mainline yet, so currently we assign 0xff */ @@ -145,8 +126,7 @@ static int lowpan_header_create(struct sk_buff *skb, /* intra-PAN communications */ da.pan_id = ieee802154_mlme_ops(dev)->get_pan_id(dev); - /* - * if the destination address is the broadcast address, use the + /* if the destination address is the broadcast address, use the * corresponding short address */ if (lowpan_is_addr_broadcast(daddr)) { @@ -188,69 +168,6 @@ static int lowpan_give_skb_to_devices(struct sk_buff *skb, return stat; } -static void lowpan_fragment_timer_expired(unsigned long entry_addr) -{ - struct lowpan_fragment *entry = (struct lowpan_fragment *)entry_addr; - - pr_debug("timer expired for frame with tag %d\n", entry->tag); - - list_del(&entry->list); - dev_kfree_skb(entry->skb); - kfree(entry); -} - -static struct lowpan_fragment * -lowpan_alloc_new_frame(struct sk_buff *skb, u16 len, u16 tag) -{ - struct lowpan_fragment *frame; - - frame = kzalloc(sizeof(struct lowpan_fragment), - GFP_ATOMIC); - if (!frame) - goto frame_err; - - INIT_LIST_HEAD(&frame->list); - - frame->length = len; - frame->tag = tag; - - /* allocate buffer for frame assembling */ - frame->skb = netdev_alloc_skb_ip_align(skb->dev, frame->length + - sizeof(struct ipv6hdr)); - - if (!frame->skb) - goto skb_err; - - frame->skb->priority = skb->priority; - - /* reserve headroom for uncompressed ipv6 header */ - skb_reserve(frame->skb, sizeof(struct ipv6hdr)); - skb_put(frame->skb, frame->length); - - /* copy the first control block to keep a - * trace of the link-layer addresses in case - * of a link-local compressed address - */ - memcpy(frame->skb->cb, skb->cb, sizeof(skb->cb)); - - init_timer(&frame->timer); - /* time out is the same as for ipv6 - 60 sec */ - frame->timer.expires = jiffies + LOWPAN_FRAG_TIMEOUT; - frame->timer.data = (unsigned long)frame; - frame->timer.function = lowpan_fragment_timer_expired; - - add_timer(&frame->timer); - - list_add_tail(&frame->list, &lowpan_fragments); - - return frame; - -skb_err: - kfree(frame); -frame_err: - return NULL; -} - static int process_data(struct sk_buff *skb) { u8 iphc0, iphc1; @@ -264,94 +181,6 @@ static int process_data(struct sk_buff *skb) if (lowpan_fetch_skb_u8(skb, &iphc0)) goto drop; - /* fragments assembling */ - switch (iphc0 & LOWPAN_DISPATCH_MASK) { - case LOWPAN_DISPATCH_FRAG1: - case LOWPAN_DISPATCH_FRAGN: - { - struct lowpan_fragment *frame; - /* slen stores the rightmost 8 bits of the 11 bits length */ - u8 slen, offset = 0; - u16 len, tag; - bool found = false; - - if (lowpan_fetch_skb_u8(skb, &slen) || /* frame length */ - lowpan_fetch_skb_u16(skb, &tag)) /* fragment tag */ - goto drop; - - /* adds the 3 MSB to the 8 LSB to retrieve the 11 bits length */ - len = ((iphc0 & 7) << 8) | slen; - - if ((iphc0 & LOWPAN_DISPATCH_MASK) == LOWPAN_DISPATCH_FRAG1) { - pr_debug("%s received a FRAG1 packet (tag: %d, " - "size of the entire IP packet: %d)", - __func__, tag, len); - } else { /* FRAGN */ - if (lowpan_fetch_skb_u8(skb, &offset)) - goto unlock_and_drop; - pr_debug("%s received a FRAGN packet (tag: %d, " - "size of the entire IP packet: %d, " - "offset: %d)", __func__, tag, len, offset * 8); - } - - /* - * check if frame assembling with the same tag is - * already in progress - */ - spin_lock_bh(&flist_lock); - - list_for_each_entry(frame, &lowpan_fragments, list) - if (frame->tag == tag) { - found = true; - break; - } - - /* alloc new frame structure */ - if (!found) { - pr_debug("%s first fragment received for tag %d, " - "begin packet reassembly", __func__, tag); - frame = lowpan_alloc_new_frame(skb, len, tag); - if (!frame) - goto unlock_and_drop; - } - - /* if payload fits buffer, copy it */ - if (likely((offset * 8 + skb->len) <= frame->length)) - skb_copy_to_linear_data_offset(frame->skb, offset * 8, - skb->data, skb->len); - else - goto unlock_and_drop; - - frame->bytes_rcv += skb->len; - - /* frame assembling complete */ - if ((frame->bytes_rcv == frame->length) && - frame->timer.expires > jiffies) { - /* if timer haven't expired - first of all delete it */ - del_timer_sync(&frame->timer); - list_del(&frame->list); - spin_unlock_bh(&flist_lock); - - pr_debug("%s successfully reassembled fragment " - "(tag %d)", __func__, tag); - - dev_kfree_skb(skb); - skb = frame->skb; - kfree(frame); - - if (lowpan_fetch_skb_u8(skb, &iphc0)) - goto drop; - - break; - } - spin_unlock_bh(&flist_lock); - - return kfree_skb(skb), 0; - } - default: - break; - } - if (lowpan_fetch_skb_u8(skb, &iphc1)) goto drop; @@ -364,8 +193,6 @@ static int process_data(struct sk_buff *skb) IEEE802154_ADDR_LEN, iphc0, iphc1, lowpan_give_skb_to_devices); -unlock_and_drop: - spin_unlock_bh(&flist_lock); drop: kfree_skb(skb); return -EINVAL; @@ -386,7 +213,7 @@ static int lowpan_set_address(struct net_device *dev, void *p) static int lowpan_fragment_xmit(struct sk_buff *skb, u8 *head, - int mlen, int plen, int offset, int type) + int mlen, int plen, int offset, int type) { struct sk_buff *frag; int hlen; @@ -422,51 +249,69 @@ lowpan_fragment_xmit(struct sk_buff *skb, u8 *head, static int lowpan_skb_fragmentation(struct sk_buff *skb, struct net_device *dev) { - int err, header_length, payload_length, tag, offset = 0; + int err; + u16 dgram_offset, dgram_size, payload_length, header_length, + lowpan_size, frag_plen, offset; + __be16 tag; u8 head[5]; header_length = skb->mac_len; payload_length = skb->len - header_length; tag = lowpan_dev_info(dev)->fragment_tag++; + lowpan_size = skb_network_header_len(skb); + dgram_size = lowpan_uncompress_size(skb, &dgram_offset) - + header_length; /* first fragment header */ - head[0] = LOWPAN_DISPATCH_FRAG1 | ((payload_length >> 8) & 0x7); - head[1] = payload_length & 0xff; + head[0] = LOWPAN_DISPATCH_FRAG1 | ((dgram_size >> 8) & 0x7); + head[1] = dgram_size & 0xff; head[2] = tag >> 8; head[3] = tag & 0xff; - err = lowpan_fragment_xmit(skb, head, header_length, LOWPAN_FRAG_SIZE, - 0, LOWPAN_DISPATCH_FRAG1); + /* calc the nearest payload length(divided to 8) for first fragment + * which fits into a IEEE802154_MTU + */ + frag_plen = round_down(IEEE802154_MTU - header_length - + LOWPAN_FRAG1_HEAD_SIZE - lowpan_size - + IEEE802154_MFR_SIZE, 8); + err = lowpan_fragment_xmit(skb, head, header_length, + frag_plen + lowpan_size, 0, + LOWPAN_DISPATCH_FRAG1); if (err) { pr_debug("%s unable to send FRAG1 packet (tag: %d)", __func__, tag); goto exit; } - offset = LOWPAN_FRAG_SIZE; + offset = lowpan_size + frag_plen; + dgram_offset += frag_plen; /* next fragment header */ head[0] &= ~LOWPAN_DISPATCH_FRAG1; head[0] |= LOWPAN_DISPATCH_FRAGN; + frag_plen = round_down(IEEE802154_MTU - header_length - + LOWPAN_FRAGN_HEAD_SIZE - IEEE802154_MFR_SIZE, 8); + while (payload_length - offset > 0) { - int len = LOWPAN_FRAG_SIZE; + int len = frag_plen; - head[4] = offset / 8; + head[4] = dgram_offset >> 3; if (payload_length - offset < len) len = payload_length - offset; - err = lowpan_fragment_xmit(skb, head, header_length, - len, offset, LOWPAN_DISPATCH_FRAGN); + err = lowpan_fragment_xmit(skb, head, header_length, len, + offset, LOWPAN_DISPATCH_FRAGN); if (err) { - pr_debug("%s unable to send a subsequent FRAGN packet " - "(tag: %d, offset: %d", __func__, tag, offset); + pr_debug("%s unable to send a FRAGN packet. (tag: %d, offset: %d)\n", + __func__, tag, offset); goto exit; } offset += len; + dgram_offset += len; } exit: @@ -594,44 +439,53 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct sk_buff *local_skb; + int ret; if (!netif_running(dev)) - goto drop; + goto drop_skb; if (dev->type != ARPHRD_IEEE802154) - goto drop; + goto drop_skb; + + local_skb = skb_clone(skb, GFP_ATOMIC); + if (!local_skb) + goto drop_skb; + + kfree_skb(skb); /* check that it's our buffer */ if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { - /* Copy the packet so that the IPv6 header is - * properly aligned. - */ - local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, - skb_tailroom(skb), GFP_ATOMIC); - if (!local_skb) - goto drop; - local_skb->protocol = htons(ETH_P_IPV6); local_skb->pkt_type = PACKET_HOST; /* Pull off the 1-byte of 6lowpan header. */ skb_pull(local_skb, 1); - lowpan_give_skb_to_devices(local_skb, NULL); - - kfree_skb(local_skb); - kfree_skb(skb); + ret = lowpan_give_skb_to_devices(local_skb, NULL); + if (ret == NET_RX_DROP) + goto drop; } else { switch (skb->data[0] & 0xe0) { case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ + ret = process_data(local_skb); + if (ret == NET_RX_DROP) + goto drop; + break; case LOWPAN_DISPATCH_FRAG1: /* first fragment header */ + ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAG1); + if (ret == 1) { + ret = process_data(local_skb); + if (ret == NET_RX_DROP) + goto drop; + } + break; case LOWPAN_DISPATCH_FRAGN: /* next fragments headers */ - local_skb = skb_clone(skb, GFP_ATOMIC); - if (!local_skb) - goto drop; - process_data(local_skb); - - kfree_skb(skb); + ret = lowpan_frag_rcv(local_skb, LOWPAN_DISPATCH_FRAGN); + if (ret == 1) { + ret = process_data(local_skb); + if (ret == NET_RX_DROP) + goto drop; + } break; default: break; @@ -639,9 +493,9 @@ static int lowpan_rcv(struct sk_buff *skb, struct net_device *dev, } return NET_RX_SUCCESS; - -drop: +drop_skb: kfree_skb(skb); +drop: return NET_RX_DROP; } @@ -668,7 +522,7 @@ static int lowpan_newlink(struct net *src_net, struct net_device *dev, lowpan_dev_info(dev)->fragment_tag = 0; mutex_init(&lowpan_dev_info(dev)->dev_list_mtx); - entry = kzalloc(sizeof(struct lowpan_dev_record), GFP_KERNEL); + entry = kzalloc(sizeof(*entry), GFP_KERNEL); if (!entry) { dev_put(real_dev); lowpan_dev_info(dev)->real_dev = NULL; @@ -769,43 +623,40 @@ static int __init lowpan_init_module(void) { int err = 0; - err = lowpan_netlink_init(); + err = lowpan_net_frag_init(); if (err < 0) goto out; + err = lowpan_netlink_init(); + if (err < 0) + goto out_frag; + dev_add_pack(&lowpan_packet_type); err = register_netdevice_notifier(&lowpan_dev_notifier); - if (err < 0) { - dev_remove_pack(&lowpan_packet_type); - lowpan_netlink_fini(); - } + if (err < 0) + goto out_pack; + + return 0; + +out_pack: + dev_remove_pack(&lowpan_packet_type); + lowpan_netlink_fini(); +out_frag: + lowpan_net_frag_exit(); out: return err; } static void __exit lowpan_cleanup_module(void) { - struct lowpan_fragment *frame, *tframe; - lowpan_netlink_fini(); dev_remove_pack(&lowpan_packet_type); - unregister_netdevice_notifier(&lowpan_dev_notifier); + lowpan_net_frag_exit(); - /* Now 6lowpan packet_type is removed, so no new fragments are - * expected on RX, therefore that's the time to clean incomplete - * fragments. - */ - spin_lock_bh(&flist_lock); - list_for_each_entry_safe(frame, tframe, &lowpan_fragments, list) { - del_timer_sync(&frame->timer); - list_del(&frame->list); - dev_kfree_skb(frame->skb); - kfree(frame); - } - spin_unlock_bh(&flist_lock); + unregister_netdevice_notifier(&lowpan_dev_notifier); } module_init(lowpan_init_module); diff --git a/net/ieee802154/Makefile b/net/ieee802154/Makefile index e8f05885ced6..b113fc4be3e0 100644 --- a/net/ieee802154/Makefile +++ b/net/ieee802154/Makefile @@ -2,5 +2,6 @@ obj-$(CONFIG_IEEE802154) += ieee802154.o af_802154.o obj-$(CONFIG_IEEE802154_6LOWPAN) += 6lowpan.o obj-$(CONFIG_6LOWPAN_IPHC) += 6lowpan_iphc.o +6lowpan-y := 6lowpan_rtnl.o reassembly.o ieee802154-y := netlink.o nl-mac.o nl-phy.o nl_policy.o wpan-class.o af_802154-y := af_ieee802154.o raw.o dgram.o diff --git a/net/ieee802154/reassembly.c b/net/ieee802154/reassembly.c new file mode 100644 index 000000000000..eb5995e74316 --- /dev/null +++ b/net/ieee802154/reassembly.c @@ -0,0 +1,564 @@ +/* 6LoWPAN fragment reassembly + * + * + * Authors: + * Alexander Aring <aar@pengutronix.de> + * + * Based on: net/ipv6/reassembly.c + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define pr_fmt(fmt) "6LoWPAN: " fmt + +#include <linux/net.h> +#include <linux/list.h> +#include <linux/netdevice.h> +#include <linux/random.h> +#include <linux/jhash.h> +#include <linux/skbuff.h> +#include <linux/slab.h> +#include <linux/export.h> + +#include <net/ieee802154_netdev.h> +#include <net/ipv6.h> +#include <net/inet_frag.h> + +#include "6lowpan.h" +#include "reassembly.h" + +static struct inet_frags lowpan_frags; + +static int lowpan_frag_reasm(struct lowpan_frag_queue *fq, + struct sk_buff *prev, struct net_device *dev); + +static unsigned int lowpan_hash_frag(__be16 tag, __be16 d_size, + const struct ieee802154_addr *saddr, + const struct ieee802154_addr *daddr) +{ + u32 c; + + net_get_random_once(&lowpan_frags.rnd, sizeof(lowpan_frags.rnd)); + c = jhash_3words(ieee802154_addr_hash(saddr), + ieee802154_addr_hash(daddr), + (__force u32)(tag + (d_size << 16)), + lowpan_frags.rnd); + + return c & (INETFRAGS_HASHSZ - 1); +} + +static unsigned int lowpan_hashfn(struct inet_frag_queue *q) +{ + struct lowpan_frag_queue *fq; + + fq = container_of(q, struct lowpan_frag_queue, q); + return lowpan_hash_frag(fq->tag, fq->d_size, &fq->saddr, &fq->daddr); +} + +bool lowpan_frag_match(struct inet_frag_queue *q, void *a) +{ + struct lowpan_frag_queue *fq; + struct lowpan_create_arg *arg = a; + + fq = container_of(q, struct lowpan_frag_queue, q); + return fq->tag == arg->tag && fq->d_size == arg->d_size && + ieee802154_addr_addr_equal(&fq->saddr, arg->src) && + ieee802154_addr_addr_equal(&fq->daddr, arg->dst); +} +EXPORT_SYMBOL(lowpan_frag_match); + +void lowpan_frag_init(struct inet_frag_queue *q, void *a) +{ + struct lowpan_frag_queue *fq; + struct lowpan_create_arg *arg = a; + + fq = container_of(q, struct lowpan_frag_queue, q); + + fq->tag = arg->tag; + fq->d_size = arg->d_size; + fq->saddr = *arg->src; + fq->daddr = *arg->dst; +} +EXPORT_SYMBOL(lowpan_frag_init); + +void lowpan_expire_frag_queue(struct frag_queue *fq, struct inet_frags *frags) +{ + spin_lock(&fq->q.lock); + + if (fq->q.last_in & INET_FRAG_COMPLETE) + goto out; + + inet_frag_kill(&fq->q, frags); +out: + spin_unlock(&fq->q.lock); + inet_frag_put(&fq->q, frags); +} +EXPORT_SYMBOL(lowpan_expire_frag_queue); + +static void lowpan_frag_expire(unsigned long data) +{ + struct frag_queue *fq; + struct net *net; + + fq = container_of((struct inet_frag_queue *)data, struct frag_queue, q); + net = container_of(fq->q.net, struct net, ieee802154_lowpan.frags); + + lowpan_expire_frag_queue(fq, &lowpan_frags); +} + +static inline struct lowpan_frag_queue * +fq_find(struct net *net, const struct ieee802154_frag_info *frag_info, + const struct ieee802154_addr *src, const struct ieee802154_addr *dst) +{ + struct inet_frag_queue *q; + struct lowpan_create_arg arg; + unsigned int hash; + + arg.tag = frag_info->d_tag; + arg.d_size = frag_info->d_size; + arg.src = src; + arg.dst = dst; + + read_lock(&lowpan_frags.lock); + hash = lowpan_hash_frag(frag_info->d_tag, frag_info->d_size, src, dst); + + q = inet_frag_find(&net->ieee802154_lowpan.frags, + &lowpan_frags, &arg, hash); + if (IS_ERR_OR_NULL(q)) { + inet_frag_maybe_warn_overflow(q, pr_fmt()); + return NULL; + } + return container_of(q, struct lowpan_frag_queue, q); +} + +static int lowpan_frag_queue(struct lowpan_frag_queue *fq, + struct sk_buff *skb, const u8 frag_type) +{ + struct sk_buff *prev, *next; + struct net_device *dev; + int end, offset; + + if (fq->q.last_in & INET_FRAG_COMPLETE) + goto err; + + offset = mac_cb(skb)->frag_info.d_offset << 3; + end = mac_cb(skb)->frag_info.d_size; + + /* Is this the final fragment? */ + if (offset + skb->len == end) { + /* If we already have some bits beyond end + * or have different end, the segment is corrupted. + */ + if (end < fq->q.len || + ((fq->q.last_in & INET_FRAG_LAST_IN) && end != fq->q.len)) + goto err; + fq->q.last_in |= INET_FRAG_LAST_IN; + fq->q.len = end; + } else { + if (end > fq->q.len) { + /* Some bits beyond end -> corruption. */ + if (fq->q.last_in & INET_FRAG_LAST_IN) + goto err; + fq->q.len = end; + } + } + + /* Find out which fragments are in front and at the back of us + * in the chain of fragments so far. We must know where to put + * this fragment, right? + */ + prev = fq->q.fragments_tail; + if (!prev || mac_cb(prev)->frag_info.d_offset < + mac_cb(skb)->frag_info.d_offset) { + next = NULL; + goto found; + } + prev = NULL; + for (next = fq->q.fragments; next != NULL; next = next->next) { + if (mac_cb(next)->frag_info.d_offset >= + mac_cb(skb)->frag_info.d_offset) + break; /* bingo! */ + prev = next; + } + +found: + /* Insert this fragment in the chain of fragments. */ + skb->next = next; + if (!next) + fq->q.fragments_tail = skb; + if (prev) + prev->next = skb; + else + fq->q.fragments = skb; + + dev = skb->dev; + if (dev) + 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); + fq->q.last_in |= INET_FRAG_FIRST_IN; + } else { + fq->q.meat += skb->len; + } + add_frag_mem_limit(&fq->q, skb->truesize); + + if (fq->q.last_in == (INET_FRAG_FIRST_IN | INET_FRAG_LAST_IN) && + fq->q.meat == fq->q.len) { + int res; + unsigned long orefdst = skb->_skb_refdst; + + skb->_skb_refdst = 0UL; + res = lowpan_frag_reasm(fq, prev, dev); + skb->_skb_refdst = orefdst; + return res; + } + + inet_frag_lru_move(&fq->q); + return -1; +err: + kfree_skb(skb); + return -1; +} + +/* Check if this packet is complete. + * Returns NULL on failure by any reason, and pointer + * to current nexthdr field in reassembled frame. + * + * It is called with locked fq, and caller must check that + * queue is eligible for reassembly i.e. it is not COMPLETE, + * 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 sk_buff *fp, *head = fq->q.fragments; + int sum_truesize; + + inet_frag_kill(&fq->q, &lowpan_frags); + + /* Make the one we just received the head. */ + if (prev) { + head = prev->next; + fp = skb_clone(head, GFP_ATOMIC); + + if (!fp) + goto out_oom; + + fp->next = head->next; + if (!fp->next) + fq->q.fragments_tail = fp; + prev->next = fp; + + skb_morph(head, fq->q.fragments); + head->next = fq->q.fragments->next; + + consume_skb(fq->q.fragments); + fq->q.fragments = head; + } + + /* Head of list must not be cloned. */ + if (skb_unclone(head, GFP_ATOMIC)) + goto out_oom; + + /* If the first fragment is fragmented itself, we split + * it to two chunks: the first with data and paged part + * and the second, holding only fragments. + */ + if (skb_has_frag_list(head)) { + struct sk_buff *clone; + int i, plen = 0; + + clone = alloc_skb(0, GFP_ATOMIC); + if (!clone) + goto out_oom; + clone->next = head->next; + head->next = clone; + skb_shinfo(clone)->frag_list = skb_shinfo(head)->frag_list; + skb_frag_list_init(head); + for (i = 0; i < skb_shinfo(head)->nr_frags; i++) + plen += skb_frag_size(&skb_shinfo(head)->frags[i]); + clone->len = head->data_len - plen; + clone->data_len = clone->len; + head->data_len -= clone->len; + head->len -= clone->len; + add_frag_mem_limit(&fq->q, clone->truesize); + } + + WARN_ON(head == NULL); + + sum_truesize = head->truesize; + for (fp = head->next; fp;) { + bool headstolen; + int delta; + struct sk_buff *next = fp->next; + + sum_truesize += fp->truesize; + if (skb_try_coalesce(head, fp, &headstolen, &delta)) { + kfree_skb_partial(fp, headstolen); + } else { + if (!skb_shinfo(head)->frag_list) + skb_shinfo(head)->frag_list = fp; + head->data_len += fp->len; + head->len += fp->len; + head->truesize += fp->truesize; + } + fp = next; + } + sub_frag_mem_limit(&fq->q, sum_truesize); + + head->next = NULL; + head->dev = dev; + head->tstamp = fq->q.stamp; + + fq->q.fragments = NULL; + fq->q.fragments_tail = NULL; + + return 1; +out_oom: + net_dbg_ratelimited("lowpan_frag_reasm: no memory for reassembly\n"); + return -1; +} + +static int lowpan_get_frag_info(struct sk_buff *skb, const u8 frag_type, + struct ieee802154_frag_info *frag_info) +{ + bool fail; + u8 pattern = 0, low = 0; + + fail = lowpan_fetch_skb(skb, &pattern, 1); + fail |= lowpan_fetch_skb(skb, &low, 1); + frag_info->d_size = (pattern & 7) << 8 | low; + fail |= lowpan_fetch_skb(skb, &frag_info->d_tag, 2); + + if (frag_type == LOWPAN_DISPATCH_FRAGN) { + fail |= lowpan_fetch_skb(skb, &frag_info->d_offset, 1); + } else { + skb_reset_network_header(skb); + frag_info->d_offset = 0; + } + + if (unlikely(fail)) + return -EIO; + + return 0; +} + +int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type) +{ + struct lowpan_frag_queue *fq; + struct net *net = dev_net(skb->dev); + struct ieee802154_frag_info *frag_info = &mac_cb(skb)->frag_info; + int err; + + err = lowpan_get_frag_info(skb, frag_type, frag_info); + if (err < 0) + goto err; + + if (frag_info->d_size > net->ieee802154_lowpan.max_dsize) + goto err; + + inet_frag_evictor(&net->ieee802154_lowpan.frags, &lowpan_frags, false); + + fq = fq_find(net, frag_info, &mac_cb(skb)->sa, &mac_cb(skb)->da); + if (fq != NULL) { + int ret; + spin_lock(&fq->q.lock); + ret = lowpan_frag_queue(fq, skb, frag_type); + spin_unlock(&fq->q.lock); + + inet_frag_put(&fq->q, &lowpan_frags); + return ret; + } + +err: + kfree_skb(skb); + return -1; +} +EXPORT_SYMBOL(lowpan_frag_rcv); + +#ifdef CONFIG_SYSCTL +static struct ctl_table lowpan_frags_ns_ctl_table[] = { + { + .procname = "6lowpanfrag_high_thresh", + .data = &init_net.ieee802154_lowpan.frags.high_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "6lowpanfrag_low_thresh", + .data = &init_net.ieee802154_lowpan.frags.low_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { + .procname = "6lowpanfrag_time", + .data = &init_net.ieee802154_lowpan.frags.timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "6lowpanfrag_max_datagram_size", + .data = &init_net.ieee802154_lowpan.max_dsize, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec + }, + { } +}; + +static struct ctl_table lowpan_frags_ctl_table[] = { + { + .procname = "6lowpanfrag_secret_interval", + .data = &lowpan_frags.secret_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { } +}; + +static int __net_init lowpan_frags_ns_sysctl_register(struct net *net) +{ + struct ctl_table *table; + struct ctl_table_header *hdr; + + table = lowpan_frags_ns_ctl_table; + if (!net_eq(net, &init_net)) { + table = kmemdup(table, sizeof(lowpan_frags_ns_ctl_table), + GFP_KERNEL); + if (table == NULL) + goto err_alloc; + + table[0].data = &net->ieee802154_lowpan.frags.high_thresh; + table[1].data = &net->ieee802154_lowpan.frags.low_thresh; + table[2].data = &net->ieee802154_lowpan.frags.timeout; + table[2].data = &net->ieee802154_lowpan.max_dsize; + + /* Don't export sysctls to unprivileged users */ + if (net->user_ns != &init_user_ns) + table[0].procname = NULL; + } + + hdr = register_net_sysctl(net, "net/ieee802154/6lowpan", table); + if (hdr == NULL) + goto err_reg; + + net->ieee802154_lowpan.sysctl.frags_hdr = hdr; + return 0; + +err_reg: + if (!net_eq(net, &init_net)) + kfree(table); +err_alloc: + return -ENOMEM; +} + +static void __net_exit lowpan_frags_ns_sysctl_unregister(struct net *net) +{ + struct ctl_table *table; + + table = net->ieee802154_lowpan.sysctl.frags_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ieee802154_lowpan.sysctl.frags_hdr); + if (!net_eq(net, &init_net)) + kfree(table); +} + +static struct ctl_table_header *lowpan_ctl_header; + +static int lowpan_frags_sysctl_register(void) +{ + lowpan_ctl_header = register_net_sysctl(&init_net, + "net/ieee802154/6lowpan", + lowpan_frags_ctl_table); + return lowpan_ctl_header == NULL ? -ENOMEM : 0; +} + +static void lowpan_frags_sysctl_unregister(void) +{ + unregister_net_sysctl_table(lowpan_ctl_header); +} +#else +static inline int lowpan_frags_ns_sysctl_register(struct net *net) +{ + return 0; +} + +static inline void lowpan_frags_ns_sysctl_unregister(struct net *net) +{ +} + +static inline int lowpan_frags_sysctl_register(void) +{ + return 0; +} + +static inline void lowpan_frags_sysctl_unregister(void) +{ +} +#endif + +static int __net_init lowpan_frags_init_net(struct net *net) +{ + net->ieee802154_lowpan.frags.high_thresh = IPV6_FRAG_HIGH_THRESH; + net->ieee802154_lowpan.frags.low_thresh = IPV6_FRAG_LOW_THRESH; + net->ieee802154_lowpan.frags.timeout = IPV6_FRAG_TIMEOUT; + net->ieee802154_lowpan.max_dsize = 0xFFFF; + + inet_frags_init_net(&net->ieee802154_lowpan.frags); + + return lowpan_frags_ns_sysctl_register(net); +} + +static void __net_exit lowpan_frags_exit_net(struct net *net) +{ + lowpan_frags_ns_sysctl_unregister(net); + inet_frags_exit_net(&net->ieee802154_lowpan.frags, &lowpan_frags); +} + +static struct pernet_operations lowpan_frags_ops = { + .init = lowpan_frags_init_net, + .exit = lowpan_frags_exit_net, +}; + +int __init lowpan_net_frag_init(void) +{ + int ret; + + ret = lowpan_frags_sysctl_register(); + if (ret) + goto out; + + ret = register_pernet_subsys(&lowpan_frags_ops); + if (ret) + goto err_pernet; + + lowpan_frags.hashfn = lowpan_hashfn; + lowpan_frags.constructor = lowpan_frag_init; + lowpan_frags.destructor = NULL; + lowpan_frags.skb_free = NULL; + lowpan_frags.qsize = sizeof(struct frag_queue); + lowpan_frags.match = lowpan_frag_match; + lowpan_frags.frag_expire = lowpan_frag_expire; + lowpan_frags.secret_interval = 10 * 60 * HZ; + inet_frags_init(&lowpan_frags); +err_pernet: + lowpan_frags_sysctl_unregister(); +out: + return ret; +} + +void lowpan_net_frag_exit(void) +{ + inet_frags_fini(&lowpan_frags); + lowpan_frags_sysctl_unregister(); + unregister_pernet_subsys(&lowpan_frags_ops); +} diff --git a/net/ieee802154/reassembly.h b/net/ieee802154/reassembly.h new file mode 100644 index 000000000000..055518b9da2d --- /dev/null +++ b/net/ieee802154/reassembly.h @@ -0,0 +1,66 @@ +#ifndef __IEEE802154_6LOWPAN_REASSEMBLY_H__ +#define __IEEE802154_6LOWPAN_REASSEMBLY_H__ + +#include <net/inet_frag.h> + +struct lowpan_create_arg { + __be16 tag; + u16 d_size; + const struct ieee802154_addr *src; + const struct ieee802154_addr *dst; +}; + +/* Equivalent of ipv4 struct ip + */ +struct lowpan_frag_queue { + struct inet_frag_queue q; + + __be16 tag; + u16 d_size; + struct ieee802154_addr saddr; + struct ieee802154_addr daddr; +}; + +static inline u32 ieee802154_addr_hash(const struct ieee802154_addr *a) +{ + switch (a->addr_type) { + case IEEE802154_ADDR_LONG: + return (__force u32)((((u32 *)a->hwaddr))[0] ^ + ((u32 *)(a->hwaddr))[1]); + case IEEE802154_ADDR_SHORT: + return (__force u32)(a->short_addr); + default: + return 0; + } +} + +static inline bool ieee802154_addr_addr_equal(const struct ieee802154_addr *a1, + const struct ieee802154_addr *a2) +{ + if (a1->pan_id != a2->pan_id) + return false; + + if (a1->addr_type != a2->addr_type) + return false; + + switch (a1->addr_type) { + case IEEE802154_ADDR_LONG: + if (memcmp(a1->hwaddr, a2->hwaddr, IEEE802154_ADDR_LEN)) + return false; + break; + case IEEE802154_ADDR_SHORT: + if (a1->short_addr != a2->short_addr) + return false; + break; + default: + return false; + } + + return true; +} + +int lowpan_frag_rcv(struct sk_buff *skb, const u8 frag_type); +void lowpan_net_frag_exit(void); +int lowpan_net_frag_init(void); + +#endif /* __IEEE802154_6LOWPAN_REASSEMBLY_H__ */ |