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![Thomas Gleixner](/assets/img/avatar_default.png)
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license 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 you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Armijn Hemel <armijn@tjaldur.nl> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190530000437.338011816@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
188 lines
4.3 KiB
C
188 lines
4.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (C) 2010: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
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* Copyright (C) 2015: Linus Lüssing <linus.luessing@c0d3.blue>
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*
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* Based on the MLD support added to br_multicast.c by YOSHIFUJI Hideaki.
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*/
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#include <linux/skbuff.h>
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#include <net/ipv6.h>
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#include <net/mld.h>
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#include <net/addrconf.h>
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#include <net/ip6_checksum.h>
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static int ipv6_mc_check_ip6hdr(struct sk_buff *skb)
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{
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const struct ipv6hdr *ip6h;
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unsigned int len;
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unsigned int offset = skb_network_offset(skb) + sizeof(*ip6h);
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if (!pskb_may_pull(skb, offset))
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return -EINVAL;
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ip6h = ipv6_hdr(skb);
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if (ip6h->version != 6)
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return -EINVAL;
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len = offset + ntohs(ip6h->payload_len);
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if (skb->len < len || len <= offset)
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return -EINVAL;
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skb_set_transport_header(skb, offset);
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return 0;
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}
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static int ipv6_mc_check_exthdrs(struct sk_buff *skb)
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{
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const struct ipv6hdr *ip6h;
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int offset;
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u8 nexthdr;
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__be16 frag_off;
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ip6h = ipv6_hdr(skb);
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if (ip6h->nexthdr != IPPROTO_HOPOPTS)
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return -ENOMSG;
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nexthdr = ip6h->nexthdr;
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offset = skb_network_offset(skb) + sizeof(*ip6h);
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offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
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if (offset < 0)
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return -EINVAL;
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if (nexthdr != IPPROTO_ICMPV6)
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return -ENOMSG;
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skb_set_transport_header(skb, offset);
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return 0;
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}
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static int ipv6_mc_check_mld_reportv2(struct sk_buff *skb)
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{
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unsigned int len = skb_transport_offset(skb);
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len += sizeof(struct mld2_report);
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return ipv6_mc_may_pull(skb, len) ? 0 : -EINVAL;
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}
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static int ipv6_mc_check_mld_query(struct sk_buff *skb)
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{
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unsigned int transport_len = ipv6_transport_len(skb);
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struct mld_msg *mld;
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unsigned int len;
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/* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
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if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
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return -EINVAL;
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/* MLDv1? */
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if (transport_len != sizeof(struct mld_msg)) {
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/* or MLDv2? */
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if (transport_len < sizeof(struct mld2_query))
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return -EINVAL;
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len = skb_transport_offset(skb) + sizeof(struct mld2_query);
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if (!ipv6_mc_may_pull(skb, len))
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return -EINVAL;
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}
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mld = (struct mld_msg *)skb_transport_header(skb);
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/* RFC2710+RFC3810 (MLDv1+MLDv2) require the multicast link layer
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* all-nodes destination address (ff02::1) for general queries
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*/
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if (ipv6_addr_any(&mld->mld_mca) &&
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!ipv6_addr_is_ll_all_nodes(&ipv6_hdr(skb)->daddr))
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return -EINVAL;
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return 0;
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}
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static int ipv6_mc_check_mld_msg(struct sk_buff *skb)
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{
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unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg);
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struct mld_msg *mld;
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if (!ipv6_mc_may_pull(skb, len))
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return -EINVAL;
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mld = (struct mld_msg *)skb_transport_header(skb);
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switch (mld->mld_type) {
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case ICMPV6_MGM_REDUCTION:
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case ICMPV6_MGM_REPORT:
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return 0;
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case ICMPV6_MLD2_REPORT:
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return ipv6_mc_check_mld_reportv2(skb);
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case ICMPV6_MGM_QUERY:
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return ipv6_mc_check_mld_query(skb);
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default:
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return -ENOMSG;
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}
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}
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static inline __sum16 ipv6_mc_validate_checksum(struct sk_buff *skb)
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{
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return skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo);
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}
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int ipv6_mc_check_icmpv6(struct sk_buff *skb)
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{
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unsigned int len = skb_transport_offset(skb) + sizeof(struct icmp6hdr);
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unsigned int transport_len = ipv6_transport_len(skb);
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struct sk_buff *skb_chk;
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if (!ipv6_mc_may_pull(skb, len))
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return -EINVAL;
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skb_chk = skb_checksum_trimmed(skb, transport_len,
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ipv6_mc_validate_checksum);
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if (!skb_chk)
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return -EINVAL;
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if (skb_chk != skb)
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kfree_skb(skb_chk);
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return 0;
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}
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EXPORT_SYMBOL(ipv6_mc_check_icmpv6);
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/**
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* ipv6_mc_check_mld - checks whether this is a sane MLD packet
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* @skb: the skb to validate
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*
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* Checks whether an IPv6 packet is a valid MLD packet. If so sets
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* skb transport header accordingly and returns zero.
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*
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* -EINVAL: A broken packet was detected, i.e. it violates some internet
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* standard
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* -ENOMSG: IP header validation succeeded but it is not an MLD packet.
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* -ENOMEM: A memory allocation failure happened.
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*
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* Caller needs to set the skb network header and free any returned skb if it
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* differs from the provided skb.
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*/
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int ipv6_mc_check_mld(struct sk_buff *skb)
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{
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int ret;
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ret = ipv6_mc_check_ip6hdr(skb);
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if (ret < 0)
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return ret;
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ret = ipv6_mc_check_exthdrs(skb);
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if (ret < 0)
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return ret;
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ret = ipv6_mc_check_icmpv6(skb);
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if (ret < 0)
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return ret;
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return ipv6_mc_check_mld_msg(skb);
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}
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EXPORT_SYMBOL(ipv6_mc_check_mld);
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