^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /* Copyright (C) 2010: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2015: Linus Lüssing <linus.luessing@c0d3.blue>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Based on the MLD support added to br_multicast.c by YOSHIFUJI Hideaki.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/skbuff.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <net/ipv6.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <net/mld.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <net/addrconf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <net/ip6_checksum.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) static int ipv6_mc_check_ip6hdr(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) const struct ipv6hdr *ip6h;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) unsigned int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) unsigned int offset = skb_network_offset(skb) + sizeof(*ip6h);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) if (!pskb_may_pull(skb, offset))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) ip6h = ipv6_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) if (ip6h->version != 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) len = offset + ntohs(ip6h->payload_len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) if (skb->len < len || len <= offset)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) skb_set_transport_header(skb, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static int ipv6_mc_check_exthdrs(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) const struct ipv6hdr *ip6h;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) int offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) u8 nexthdr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) __be16 frag_off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) ip6h = ipv6_hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) if (ip6h->nexthdr != IPPROTO_HOPOPTS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) return -ENOMSG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) nexthdr = ip6h->nexthdr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) offset = skb_network_offset(skb) + sizeof(*ip6h);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) if (offset < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) if (nexthdr != IPPROTO_ICMPV6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) return -ENOMSG;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) skb_set_transport_header(skb, offset);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) static int ipv6_mc_check_mld_reportv2(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) unsigned int len = skb_transport_offset(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) len += sizeof(struct mld2_report);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) return ipv6_mc_may_pull(skb, len) ? 0 : -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) static int ipv6_mc_check_mld_query(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) unsigned int transport_len = ipv6_transport_len(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) struct mld_msg *mld;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) unsigned int len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) /* RFC2710+RFC3810 (MLDv1+MLDv2) require link-local source addresses */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (!(ipv6_addr_type(&ipv6_hdr(skb)->saddr) & IPV6_ADDR_LINKLOCAL))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /* MLDv1? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) if (transport_len != sizeof(struct mld_msg)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) /* or MLDv2? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) if (transport_len < sizeof(struct mld2_query))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) len = skb_transport_offset(skb) + sizeof(struct mld2_query);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (!ipv6_mc_may_pull(skb, len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) mld = (struct mld_msg *)skb_transport_header(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /* RFC2710+RFC3810 (MLDv1+MLDv2) require the multicast link layer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) * all-nodes destination address (ff02::1) for general queries
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (ipv6_addr_any(&mld->mld_mca) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) !ipv6_addr_is_ll_all_nodes(&ipv6_hdr(skb)->daddr))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) static int ipv6_mc_check_mld_msg(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) unsigned int len = skb_transport_offset(skb) + sizeof(struct mld_msg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) struct mld_msg *mld;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!ipv6_mc_may_pull(skb, len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) mld = (struct mld_msg *)skb_transport_header(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) switch (mld->mld_type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) case ICMPV6_MGM_REDUCTION:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) case ICMPV6_MGM_REPORT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) case ICMPV6_MLD2_REPORT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) return ipv6_mc_check_mld_reportv2(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) case ICMPV6_MGM_QUERY:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return ipv6_mc_check_mld_query(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) static inline __sum16 ipv6_mc_validate_checksum(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) return skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) static int ipv6_mc_check_icmpv6(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) unsigned int len = skb_transport_offset(skb) + sizeof(struct icmp6hdr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) unsigned int transport_len = ipv6_transport_len(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) struct sk_buff *skb_chk;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) if (!ipv6_mc_may_pull(skb, len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) skb_chk = skb_checksum_trimmed(skb, transport_len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) ipv6_mc_validate_checksum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if (!skb_chk)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) if (skb_chk != skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) kfree_skb(skb_chk);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) * ipv6_mc_check_mld - checks whether this is a sane MLD packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) * @skb: the skb to validate
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) * Checks whether an IPv6 packet is a valid MLD packet. If so sets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) * skb transport header accordingly and returns zero.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * -EINVAL: A broken packet was detected, i.e. it violates some internet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) * standard
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * -ENOMSG: IP header validation succeeded but it is not an ICMPv6 packet
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * with a hop-by-hop option.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) * -ENODATA: IP+ICMPv6 header with hop-by-hop option validation succeeded
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) * but it is not an MLD packet.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) * -ENOMEM: A memory allocation failure happened.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) * Caller needs to set the skb network header and free any returned skb if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) * differs from the provided skb.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) int ipv6_mc_check_mld(struct sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) ret = ipv6_mc_check_ip6hdr(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) ret = ipv6_mc_check_exthdrs(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) ret = ipv6_mc_check_icmpv6(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) return ipv6_mc_check_mld_msg(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) EXPORT_SYMBOL(ipv6_mc_check_mld);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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