| /* |
| * Internet Control Message Protocol (ICMPv6) |
| * Linux INET6 implementation |
| * |
| * Authors: |
| * Pedro Roque <roque@di.fc.ul.pt> |
| * |
| * Based on net/ipv4/icmp.c |
| * |
| * RFC 1885 |
| * |
| * 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. |
| */ |
| |
| /* |
| * Changes: |
| * |
| * Andi Kleen : exception handling |
| * Andi Kleen add rate limits. never reply to a icmp. |
| * add more length checks and other fixes. |
| * yoshfuji : ensure to sent parameter problem for |
| * fragments. |
| * YOSHIFUJI Hideaki @USAGI: added sysctl for icmp rate limit. |
| * Randy Dunlap and |
| * YOSHIFUJI Hideaki @USAGI: Per-interface statistics support |
| * Kazunori MIYAZAWA @USAGI: change output process to use ip6_append_data |
| */ |
| |
| #define pr_fmt(fmt) "IPv6: " fmt |
| |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/types.h> |
| #include <linux/socket.h> |
| #include <linux/in.h> |
| #include <linux/kernel.h> |
| #include <linux/sockios.h> |
| #include <linux/net.h> |
| #include <linux/skbuff.h> |
| #include <linux/init.h> |
| #include <linux/netfilter.h> |
| #include <linux/slab.h> |
| |
| #ifdef CONFIG_SYSCTL |
| #include <linux/sysctl.h> |
| #endif |
| |
| #include <linux/inet.h> |
| #include <linux/netdevice.h> |
| #include <linux/icmpv6.h> |
| |
| #include <net/ip.h> |
| #include <net/sock.h> |
| |
| #include <net/ipv6.h> |
| #include <net/ip6_checksum.h> |
| #include <net/ping.h> |
| #include <net/protocol.h> |
| #include <net/raw.h> |
| #include <net/rawv6.h> |
| #include <net/transp_v6.h> |
| #include <net/ip6_route.h> |
| #include <net/addrconf.h> |
| #include <net/icmp.h> |
| #include <net/xfrm.h> |
| #include <net/inet_common.h> |
| #include <net/dsfield.h> |
| #include <net/l3mdev.h> |
| |
| #include <linux/uaccess.h> |
| |
| /* |
| * The ICMP socket(s). This is the most convenient way to flow control |
| * our ICMP output as well as maintain a clean interface throughout |
| * all layers. All Socketless IP sends will soon be gone. |
| * |
| * On SMP we have one ICMP socket per-cpu. |
| */ |
| static inline struct sock *icmpv6_sk(struct net *net) |
| { |
| return *this_cpu_ptr(net->ipv6.icmp_sk); |
| } |
| |
| static int icmpv6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, |
| u8 type, u8 code, int offset, __be32 info) |
| { |
| /* icmpv6_notify checks 8 bytes can be pulled, icmp6hdr is 8 bytes */ |
| struct icmp6hdr *icmp6 = (struct icmp6hdr *) (skb->data + offset); |
| struct net *net = dev_net(skb->dev); |
| |
| if (type == ICMPV6_PKT_TOOBIG) |
| ip6_update_pmtu(skb, net, info, skb->dev->ifindex, 0, sock_net_uid(net, NULL)); |
| else if (type == NDISC_REDIRECT) |
| ip6_redirect(skb, net, skb->dev->ifindex, 0, |
| sock_net_uid(net, NULL)); |
| |
| if (!(type & ICMPV6_INFOMSG_MASK)) |
| if (icmp6->icmp6_type == ICMPV6_ECHO_REQUEST) |
| ping_err(skb, offset, ntohl(info)); |
| |
| return 0; |
| } |
| |
| static int icmpv6_rcv(struct sk_buff *skb); |
| |
| static const struct inet6_protocol icmpv6_protocol = { |
| .handler = icmpv6_rcv, |
| .err_handler = icmpv6_err, |
| .flags = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL, |
| }; |
| |
| /* Called with BH disabled */ |
| static __inline__ struct sock *icmpv6_xmit_lock(struct net *net) |
| { |
| struct sock *sk; |
| |
| sk = icmpv6_sk(net); |
| if (unlikely(!spin_trylock(&sk->sk_lock.slock))) { |
| /* This can happen if the output path (f.e. SIT or |
| * ip6ip6 tunnel) signals dst_link_failure() for an |
| * outgoing ICMP6 packet. |
| */ |
| return NULL; |
| } |
| return sk; |
| } |
| |
| static __inline__ void icmpv6_xmit_unlock(struct sock *sk) |
| { |
| spin_unlock(&sk->sk_lock.slock); |
| } |
| |
| /* |
| * Figure out, may we reply to this packet with icmp error. |
| * |
| * We do not reply, if: |
| * - it was icmp error message. |
| * - it is truncated, so that it is known, that protocol is ICMPV6 |
| * (i.e. in the middle of some exthdr) |
| * |
| * --ANK (980726) |
| */ |
| |
| static bool is_ineligible(const struct sk_buff *skb) |
| { |
| int ptr = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; |
| int len = skb->len - ptr; |
| __u8 nexthdr = ipv6_hdr(skb)->nexthdr; |
| __be16 frag_off; |
| |
| if (len < 0) |
| return true; |
| |
| ptr = ipv6_skip_exthdr(skb, ptr, &nexthdr, &frag_off); |
| if (ptr < 0) |
| return false; |
| if (nexthdr == IPPROTO_ICMPV6) { |
| u8 _type, *tp; |
| tp = skb_header_pointer(skb, |
| ptr+offsetof(struct icmp6hdr, icmp6_type), |
| sizeof(_type), &_type); |
| if (!tp || !(*tp & ICMPV6_INFOMSG_MASK)) |
| return true; |
| } |
| return false; |
| } |
| |
| static bool icmpv6_mask_allow(int type) |
| { |
| /* Informational messages are not limited. */ |
| if (type & ICMPV6_INFOMSG_MASK) |
| return true; |
| |
| /* Do not limit pmtu discovery, it would break it. */ |
| if (type == ICMPV6_PKT_TOOBIG) |
| return true; |
| |
| return false; |
| } |
| |
| static bool icmpv6_global_allow(int type) |
| { |
| if (icmpv6_mask_allow(type)) |
| return true; |
| |
| if (icmp_global_allow()) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * Check the ICMP output rate limit |
| */ |
| static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, |
| struct flowi6 *fl6) |
| { |
| struct net *net = sock_net(sk); |
| struct dst_entry *dst; |
| bool res = false; |
| |
| if (icmpv6_mask_allow(type)) |
| return true; |
| |
| /* |
| * Look up the output route. |
| * XXX: perhaps the expire for routing entries cloned by |
| * this lookup should be more aggressive (not longer than timeout). |
| */ |
| dst = ip6_route_output(net, sk, fl6); |
| if (dst->error) { |
| IP6_INC_STATS(net, ip6_dst_idev(dst), |
| IPSTATS_MIB_OUTNOROUTES); |
| } else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) { |
| res = true; |
| } else { |
| struct rt6_info *rt = (struct rt6_info *)dst; |
| int tmo = net->ipv6.sysctl.icmpv6_time; |
| struct inet_peer *peer; |
| |
| /* Give more bandwidth to wider prefixes. */ |
| if (rt->rt6i_dst.plen < 128) |
| tmo >>= ((128 - rt->rt6i_dst.plen)>>5); |
| |
| peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr, 1); |
| res = inet_peer_xrlim_allow(peer, tmo); |
| if (peer) |
| inet_putpeer(peer); |
| } |
| dst_release(dst); |
| return res; |
| } |
| |
| /* |
| * an inline helper for the "simple" if statement below |
| * checks if parameter problem report is caused by an |
| * unrecognized IPv6 option that has the Option Type |
| * highest-order two bits set to 10 |
| */ |
| |
| static bool opt_unrec(struct sk_buff *skb, __u32 offset) |
| { |
| u8 _optval, *op; |
| |
| offset += skb_network_offset(skb); |
| op = skb_header_pointer(skb, offset, sizeof(_optval), &_optval); |
| if (!op) |
| return true; |
| return (*op & 0xC0) == 0x80; |
| } |
| |
| void icmpv6_push_pending_frames(struct sock *sk, struct flowi6 *fl6, |
| struct icmp6hdr *thdr, int len) |
| { |
| struct sk_buff *skb; |
| struct icmp6hdr *icmp6h; |
| |
| skb = skb_peek(&sk->sk_write_queue); |
| if (!skb) |
| return; |
| |
| icmp6h = icmp6_hdr(skb); |
| memcpy(icmp6h, thdr, sizeof(struct icmp6hdr)); |
| icmp6h->icmp6_cksum = 0; |
| |
| if (skb_queue_len(&sk->sk_write_queue) == 1) { |
| skb->csum = csum_partial(icmp6h, |
| sizeof(struct icmp6hdr), skb->csum); |
| icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
| &fl6->daddr, |
| len, fl6->flowi6_proto, |
| skb->csum); |
| } else { |
| __wsum tmp_csum = 0; |
| |
| skb_queue_walk(&sk->sk_write_queue, skb) { |
| tmp_csum = csum_add(tmp_csum, skb->csum); |
| } |
| |
| tmp_csum = csum_partial(icmp6h, |
| sizeof(struct icmp6hdr), tmp_csum); |
| icmp6h->icmp6_cksum = csum_ipv6_magic(&fl6->saddr, |
| &fl6->daddr, |
| len, fl6->flowi6_proto, |
| tmp_csum); |
| } |
| ip6_push_pending_frames(sk); |
| } |
| |
| struct icmpv6_msg { |
| struct sk_buff *skb; |
| int offset; |
| uint8_t type; |
| }; |
| |
| static int icmpv6_getfrag(void *from, char *to, int offset, int len, int odd, struct sk_buff *skb) |
| { |
| struct icmpv6_msg *msg = (struct icmpv6_msg *) from; |
| struct sk_buff *org_skb = msg->skb; |
| __wsum csum = 0; |
| |
| csum = skb_copy_and_csum_bits(org_skb, msg->offset + offset, |
| to, len, csum); |
| skb->csum = csum_block_add(skb->csum, csum, odd); |
| if (!(msg->type & ICMPV6_INFOMSG_MASK)) |
| nf_ct_attach(skb, org_skb); |
| return 0; |
| } |
| |
| #if IS_ENABLED(CONFIG_IPV6_MIP6) |
| static void mip6_addr_swap(struct sk_buff *skb) |
| { |
| struct ipv6hdr *iph = ipv6_hdr(skb); |
| struct inet6_skb_parm *opt = IP6CB(skb); |
| struct ipv6_destopt_hao *hao; |
| struct in6_addr tmp; |
| int off; |
| |
| if (opt->dsthao) { |
| off = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO); |
| if (likely(off >= 0)) { |
| hao = (struct ipv6_destopt_hao *) |
| (skb_network_header(skb) + off); |
| tmp = iph->saddr; |
| iph->saddr = hao->addr; |
| hao->addr = tmp; |
| } |
| } |
| } |
| #else |
| static inline void mip6_addr_swap(struct sk_buff *skb) {} |
| #endif |
| |
| static struct dst_entry *icmpv6_route_lookup(struct net *net, |
| struct sk_buff *skb, |
| struct sock *sk, |
| struct flowi6 *fl6) |
| { |
| struct dst_entry *dst, *dst2; |
| struct flowi6 fl2; |
| int err; |
| |
| err = ip6_dst_lookup(net, sk, &dst, fl6); |
| if (err) |
| return ERR_PTR(err); |
| |
| /* |
| * We won't send icmp if the destination is known |
| * anycast. |
| */ |
| if (ipv6_anycast_destination(dst, &fl6->daddr)) { |
| net_dbg_ratelimited("icmp6_send: acast source\n"); |
| dst_release(dst); |
| return ERR_PTR(-EINVAL); |
| } |
| |
| /* No need to clone since we're just using its address. */ |
| dst2 = dst; |
| |
| dst = xfrm_lookup(net, dst, flowi6_to_flowi(fl6), sk, 0); |
| if (!IS_ERR(dst)) { |
| if (dst != dst2) |
| return dst; |
| } else { |
| if (PTR_ERR(dst) == -EPERM) |
| dst = NULL; |
| else |
| return dst; |
| } |
| |
| err = xfrm_decode_session_reverse(skb, flowi6_to_flowi(&fl2), AF_INET6); |
| if (err) |
| goto relookup_failed; |
| |
| err = ip6_dst_lookup(net, sk, &dst2, &fl2); |
| if (err) |
| goto relookup_failed; |
| |
| dst2 = xfrm_lookup(net, dst2, flowi6_to_flowi(&fl2), sk, XFRM_LOOKUP_ICMP); |
| if (!IS_ERR(dst2)) { |
| dst_release(dst); |
| dst = dst2; |
| } else { |
| err = PTR_ERR(dst2); |
| if (err == -EPERM) { |
| dst_release(dst); |
| return dst2; |
| } else |
| goto relookup_failed; |
| } |
| |
| relookup_failed: |
| if (dst) |
| return dst; |
| return ERR_PTR(err); |
| } |
| |
| static int icmp6_iif(const struct sk_buff *skb) |
| { |
| int iif = skb->dev->ifindex; |
| |
| /* for local traffic to local address, skb dev is the loopback |
| * device. Check if there is a dst attached to the skb and if so |
| * get the real device index. Same is needed for replies to a link |
| * local address on a device enslaved to an L3 master device |
| */ |
| if (unlikely(iif == LOOPBACK_IFINDEX || netif_is_l3_master(skb->dev))) { |
| const struct rt6_info *rt6 = skb_rt6_info(skb); |
| |
| if (rt6) |
| iif = rt6->rt6i_idev->dev->ifindex; |
| } |
| |
| return iif; |
| } |
| |
| /* |
| * Send an ICMP message in response to a packet in error |
| */ |
| static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, |
| const struct in6_addr *force_saddr) |
| { |
| struct inet6_dev *idev = NULL; |
| struct ipv6hdr *hdr = ipv6_hdr(skb); |
| struct sock *sk; |
| struct net *net; |
| struct ipv6_pinfo *np; |
| const struct in6_addr *saddr = NULL; |
| struct dst_entry *dst; |
| struct icmp6hdr tmp_hdr; |
| struct flowi6 fl6; |
| struct icmpv6_msg msg; |
| struct ipcm6_cookie ipc6; |
| int iif = 0; |
| int addr_type = 0; |
| int len; |
| u32 mark; |
| |
| if ((u8 *)hdr < skb->head || |
| (skb_network_header(skb) + sizeof(*hdr)) > skb_tail_pointer(skb)) |
| return; |
| |
| if (!skb->dev) |
| return; |
| net = dev_net(skb->dev); |
| mark = IP6_REPLY_MARK(net, skb->mark); |
| /* |
| * Make sure we respect the rules |
| * i.e. RFC 1885 2.4(e) |
| * Rule (e.1) is enforced by not using icmp6_send |
| * in any code that processes icmp errors. |
| */ |
| addr_type = ipv6_addr_type(&hdr->daddr); |
| |
| if (ipv6_chk_addr(net, &hdr->daddr, skb->dev, 0) || |
| ipv6_chk_acast_addr_src(net, skb->dev, &hdr->daddr)) |
| saddr = &hdr->daddr; |
| |
| /* |
| * Dest addr check |
| */ |
| |
| if (addr_type & IPV6_ADDR_MULTICAST || skb->pkt_type != PACKET_HOST) { |
| if (type != ICMPV6_PKT_TOOBIG && |
| !(type == ICMPV6_PARAMPROB && |
| code == ICMPV6_UNK_OPTION && |
| (opt_unrec(skb, info)))) |
| return; |
| |
| saddr = NULL; |
| } |
| |
| addr_type = ipv6_addr_type(&hdr->saddr); |
| |
| /* |
| * Source addr check |
| */ |
| |
| if (__ipv6_addr_needs_scope_id(addr_type)) { |
| iif = icmp6_iif(skb); |
| } else { |
| dst = skb_dst(skb); |
| iif = l3mdev_master_ifindex(dst ? dst->dev : skb->dev); |
| } |
| |
| /* |
| * Must not send error if the source does not uniquely |
| * identify a single node (RFC2463 Section 2.4). |
| * We check unspecified / multicast addresses here, |
| * and anycast addresses will be checked later. |
| */ |
| if ((addr_type == IPV6_ADDR_ANY) || (addr_type & IPV6_ADDR_MULTICAST)) { |
| net_dbg_ratelimited("icmp6_send: addr_any/mcast source [%pI6c > %pI6c]\n", |
| &hdr->saddr, &hdr->daddr); |
| return; |
| } |
| |
| /* |
| * Never answer to a ICMP packet. |
| */ |
| if (is_ineligible(skb)) { |
| net_dbg_ratelimited("icmp6_send: no reply to icmp error [%pI6c > %pI6c]\n", |
| &hdr->saddr, &hdr->daddr); |
| return; |
| } |
| |
| /* Needed by both icmp_global_allow and icmpv6_xmit_lock */ |
| local_bh_disable(); |
| |
| /* Check global sysctl_icmp_msgs_per_sec ratelimit */ |
| if (!(skb->dev->flags&IFF_LOOPBACK) && !icmpv6_global_allow(type)) |
| goto out_bh_enable; |
| |
| mip6_addr_swap(skb); |
| |
| memset(&fl6, 0, sizeof(fl6)); |
| fl6.flowi6_proto = IPPROTO_ICMPV6; |
| fl6.daddr = hdr->saddr; |
| if (force_saddr) |
| saddr = force_saddr; |
| if (saddr) |
| fl6.saddr = *saddr; |
| fl6.flowi6_mark = mark; |
| fl6.flowi6_oif = iif; |
| fl6.fl6_icmp_type = type; |
| fl6.fl6_icmp_code = code; |
| fl6.flowi6_uid = sock_net_uid(net, NULL); |
| fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, NULL); |
| security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
| |
| sk = icmpv6_xmit_lock(net); |
| if (!sk) |
| goto out_bh_enable; |
| |
| sk->sk_mark = mark; |
| np = inet6_sk(sk); |
| |
| if (!icmpv6_xrlim_allow(sk, type, &fl6)) |
| goto out; |
| |
| tmp_hdr.icmp6_type = type; |
| tmp_hdr.icmp6_code = code; |
| tmp_hdr.icmp6_cksum = 0; |
| tmp_hdr.icmp6_pointer = htonl(info); |
| |
| if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
| fl6.flowi6_oif = np->mcast_oif; |
| else if (!fl6.flowi6_oif) |
| fl6.flowi6_oif = np->ucast_oif; |
| |
| ipcm6_init_sk(&ipc6, np); |
| fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel); |
| |
| dst = icmpv6_route_lookup(net, skb, sk, &fl6); |
| if (IS_ERR(dst)) |
| goto out; |
| |
| ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); |
| |
| msg.skb = skb; |
| msg.offset = skb_network_offset(skb); |
| msg.type = type; |
| |
| len = skb->len - msg.offset; |
| len = min_t(unsigned int, len, IPV6_MIN_MTU - sizeof(struct ipv6hdr) - sizeof(struct icmp6hdr)); |
| if (len < 0) { |
| net_dbg_ratelimited("icmp: len problem [%pI6c > %pI6c]\n", |
| &hdr->saddr, &hdr->daddr); |
| goto out_dst_release; |
| } |
| |
| rcu_read_lock(); |
| idev = __in6_dev_get(skb->dev); |
| |
| if (ip6_append_data(sk, icmpv6_getfrag, &msg, |
| len + sizeof(struct icmp6hdr), |
| sizeof(struct icmp6hdr), |
| &ipc6, &fl6, (struct rt6_info *)dst, |
| MSG_DONTWAIT)) { |
| ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); |
| ip6_flush_pending_frames(sk); |
| } else { |
| icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
| len + sizeof(struct icmp6hdr)); |
| } |
| rcu_read_unlock(); |
| out_dst_release: |
| dst_release(dst); |
| out: |
| icmpv6_xmit_unlock(sk); |
| out_bh_enable: |
| local_bh_enable(); |
| } |
| |
| /* Slightly more convenient version of icmp6_send. |
| */ |
| void icmpv6_param_prob(struct sk_buff *skb, u8 code, int pos) |
| { |
| icmp6_send(skb, ICMPV6_PARAMPROB, code, pos, NULL); |
| kfree_skb(skb); |
| } |
| |
| /* Generate icmpv6 with type/code ICMPV6_DEST_UNREACH/ICMPV6_ADDR_UNREACH |
| * if sufficient data bytes are available |
| * @nhs is the size of the tunnel header(s) : |
| * Either an IPv4 header for SIT encap |
| * an IPv4 header + GRE header for GRE encap |
| */ |
| int ip6_err_gen_icmpv6_unreach(struct sk_buff *skb, int nhs, int type, |
| unsigned int data_len) |
| { |
| struct in6_addr temp_saddr; |
| struct rt6_info *rt; |
| struct sk_buff *skb2; |
| u32 info = 0; |
| |
| if (!pskb_may_pull(skb, nhs + sizeof(struct ipv6hdr) + 8)) |
| return 1; |
| |
| /* RFC 4884 (partial) support for ICMP extensions */ |
| if (data_len < 128 || (data_len & 7) || skb->len < data_len) |
| data_len = 0; |
| |
| skb2 = data_len ? skb_copy(skb, GFP_ATOMIC) : skb_clone(skb, GFP_ATOMIC); |
| |
| if (!skb2) |
| return 1; |
| |
| skb_dst_drop(skb2); |
| skb_pull(skb2, nhs); |
| skb_reset_network_header(skb2); |
| |
| rt = rt6_lookup(dev_net(skb->dev), &ipv6_hdr(skb2)->saddr, NULL, 0, |
| skb, 0); |
| |
| if (rt && rt->dst.dev) |
| skb2->dev = rt->dst.dev; |
| |
| ipv6_addr_set_v4mapped(ip_hdr(skb)->saddr, &temp_saddr); |
| |
| if (data_len) { |
| /* RFC 4884 (partial) support : |
| * insert 0 padding at the end, before the extensions |
| */ |
| __skb_push(skb2, nhs); |
| skb_reset_network_header(skb2); |
| memmove(skb2->data, skb2->data + nhs, data_len - nhs); |
| memset(skb2->data + data_len - nhs, 0, nhs); |
| /* RFC 4884 4.5 : Length is measured in 64-bit words, |
| * and stored in reserved[0] |
| */ |
| info = (data_len/8) << 24; |
| } |
| if (type == ICMP_TIME_EXCEEDED) |
| icmp6_send(skb2, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, |
| info, &temp_saddr); |
| else |
| icmp6_send(skb2, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, |
| info, &temp_saddr); |
| if (rt) |
| ip6_rt_put(rt); |
| |
| kfree_skb(skb2); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL(ip6_err_gen_icmpv6_unreach); |
| |
| static void icmpv6_echo_reply(struct sk_buff *skb) |
| { |
| struct net *net = dev_net(skb->dev); |
| struct sock *sk; |
| struct inet6_dev *idev; |
| struct ipv6_pinfo *np; |
| const struct in6_addr *saddr = NULL; |
| struct icmp6hdr *icmph = icmp6_hdr(skb); |
| struct icmp6hdr tmp_hdr; |
| struct flowi6 fl6; |
| struct icmpv6_msg msg; |
| struct dst_entry *dst; |
| struct ipcm6_cookie ipc6; |
| u32 mark = IP6_REPLY_MARK(net, skb->mark); |
| |
| saddr = &ipv6_hdr(skb)->daddr; |
| |
| if (!ipv6_unicast_destination(skb) && |
| !(net->ipv6.sysctl.anycast_src_echo_reply && |
| ipv6_anycast_destination(skb_dst(skb), saddr))) |
| saddr = NULL; |
| |
| memcpy(&tmp_hdr, icmph, sizeof(tmp_hdr)); |
| tmp_hdr.icmp6_type = ICMPV6_ECHO_REPLY; |
| |
| memset(&fl6, 0, sizeof(fl6)); |
| fl6.flowi6_proto = IPPROTO_ICMPV6; |
| fl6.daddr = ipv6_hdr(skb)->saddr; |
| if (saddr) |
| fl6.saddr = *saddr; |
| fl6.flowi6_oif = icmp6_iif(skb); |
| fl6.fl6_icmp_type = ICMPV6_ECHO_REPLY; |
| fl6.flowi6_mark = mark; |
| fl6.flowi6_uid = sock_net_uid(net, NULL); |
| security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); |
| |
| local_bh_disable(); |
| sk = icmpv6_xmit_lock(net); |
| if (!sk) |
| goto out_bh_enable; |
| sk->sk_mark = mark; |
| np = inet6_sk(sk); |
| |
| if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr)) |
| fl6.flowi6_oif = np->mcast_oif; |
| else if (!fl6.flowi6_oif) |
| fl6.flowi6_oif = np->ucast_oif; |
| |
| if (ip6_dst_lookup(net, sk, &dst, &fl6)) |
| goto out; |
| dst = xfrm_lookup(net, dst, flowi6_to_flowi(&fl6), sk, 0); |
| if (IS_ERR(dst)) |
| goto out; |
| |
| idev = __in6_dev_get(skb->dev); |
| |
| msg.skb = skb; |
| msg.offset = 0; |
| msg.type = ICMPV6_ECHO_REPLY; |
| |
| ipcm6_init_sk(&ipc6, np); |
| ipc6.hlimit = ip6_sk_dst_hoplimit(np, &fl6, dst); |
| ipc6.tclass = ipv6_get_dsfield(ipv6_hdr(skb)); |
| |
| if (ip6_append_data(sk, icmpv6_getfrag, &msg, |
| skb->len + sizeof(struct icmp6hdr), |
| sizeof(struct icmp6hdr), &ipc6, &fl6, |
| (struct rt6_info *)dst, MSG_DONTWAIT)) { |
| __ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS); |
| ip6_flush_pending_frames(sk); |
| } else { |
| icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr, |
| skb->len + sizeof(struct icmp6hdr)); |
| } |
| dst_release(dst); |
| out: |
| icmpv6_xmit_unlock(sk); |
| out_bh_enable: |
| local_bh_enable(); |
| } |
| |
| void icmpv6_notify(struct sk_buff *skb, u8 type, u8 code, __be32 info) |
| { |
| const struct inet6_protocol *ipprot; |
| int inner_offset; |
| __be16 frag_off; |
| u8 nexthdr; |
| struct net *net = dev_net(skb->dev); |
| |
| if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| goto out; |
| |
| nexthdr = ((struct ipv6hdr *)skb->data)->nexthdr; |
| if (ipv6_ext_hdr(nexthdr)) { |
| /* now skip over extension headers */ |
| inner_offset = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), |
| &nexthdr, &frag_off); |
| if (inner_offset < 0) |
| goto out; |
| } else { |
| inner_offset = sizeof(struct ipv6hdr); |
| } |
| |
| /* Checkin header including 8 bytes of inner protocol header. */ |
| if (!pskb_may_pull(skb, inner_offset+8)) |
| goto out; |
| |
| /* BUGGG_FUTURE: we should try to parse exthdrs in this packet. |
| Without this we will not able f.e. to make source routed |
| pmtu discovery. |
| Corresponding argument (opt) to notifiers is already added. |
| --ANK (980726) |
| */ |
| |
| ipprot = rcu_dereference(inet6_protos[nexthdr]); |
| if (ipprot && ipprot->err_handler) |
| ipprot->err_handler(skb, NULL, type, code, inner_offset, info); |
| |
| raw6_icmp_error(skb, nexthdr, type, code, inner_offset, info); |
| return; |
| |
| out: |
| __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); |
| } |
| |
| /* |
| * Handle icmp messages |
| */ |
| |
| static int icmpv6_rcv(struct sk_buff *skb) |
| { |
| struct net *net = dev_net(skb->dev); |
| struct net_device *dev = skb->dev; |
| struct inet6_dev *idev = __in6_dev_get(dev); |
| const struct in6_addr *saddr, *daddr; |
| struct icmp6hdr *hdr; |
| u8 type; |
| bool success = false; |
| |
| if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { |
| struct sec_path *sp = skb_sec_path(skb); |
| int nh; |
| |
| if (!(sp && sp->xvec[sp->len - 1]->props.flags & |
| XFRM_STATE_ICMP)) |
| goto drop_no_count; |
| |
| if (!pskb_may_pull(skb, sizeof(*hdr) + sizeof(struct ipv6hdr))) |
| goto drop_no_count; |
| |
| nh = skb_network_offset(skb); |
| skb_set_network_header(skb, sizeof(*hdr)); |
| |
| if (!xfrm6_policy_check_reverse(NULL, XFRM_POLICY_IN, skb)) |
| goto drop_no_count; |
| |
| skb_set_network_header(skb, nh); |
| } |
| |
| __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INMSGS); |
| |
| saddr = &ipv6_hdr(skb)->saddr; |
| daddr = &ipv6_hdr(skb)->daddr; |
| |
| if (skb_checksum_validate(skb, IPPROTO_ICMPV6, ip6_compute_pseudo)) { |
| net_dbg_ratelimited("ICMPv6 checksum failed [%pI6c > %pI6c]\n", |
| saddr, daddr); |
| goto csum_error; |
| } |
| |
| if (!pskb_pull(skb, sizeof(*hdr))) |
| goto discard_it; |
| |
| hdr = icmp6_hdr(skb); |
| |
| type = hdr->icmp6_type; |
| |
| ICMP6MSGIN_INC_STATS(dev_net(dev), idev, type); |
| |
| switch (type) { |
| case ICMPV6_ECHO_REQUEST: |
| if (!net->ipv6.sysctl.icmpv6_echo_ignore_all) |
| icmpv6_echo_reply(skb); |
| break; |
| |
| case ICMPV6_ECHO_REPLY: |
| success = ping_rcv(skb); |
| break; |
| |
| case ICMPV6_PKT_TOOBIG: |
| /* BUGGG_FUTURE: if packet contains rthdr, we cannot update |
| standard destination cache. Seems, only "advanced" |
| destination cache will allow to solve this problem |
| --ANK (980726) |
| */ |
| if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) |
| goto discard_it; |
| hdr = icmp6_hdr(skb); |
| |
| /* to notify */ |
| /* fall through */ |
| case ICMPV6_DEST_UNREACH: |
| case ICMPV6_TIME_EXCEED: |
| case ICMPV6_PARAMPROB: |
| icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
| break; |
| |
| case NDISC_ROUTER_SOLICITATION: |
| case NDISC_ROUTER_ADVERTISEMENT: |
| case NDISC_NEIGHBOUR_SOLICITATION: |
| case NDISC_NEIGHBOUR_ADVERTISEMENT: |
| case NDISC_REDIRECT: |
| ndisc_rcv(skb); |
| break; |
| |
| case ICMPV6_MGM_QUERY: |
| igmp6_event_query(skb); |
| break; |
| |
| case ICMPV6_MGM_REPORT: |
| igmp6_event_report(skb); |
| break; |
| |
| case ICMPV6_MGM_REDUCTION: |
| case ICMPV6_NI_QUERY: |
| case ICMPV6_NI_REPLY: |
| case ICMPV6_MLD2_REPORT: |
| case ICMPV6_DHAAD_REQUEST: |
| case ICMPV6_DHAAD_REPLY: |
| case ICMPV6_MOBILE_PREFIX_SOL: |
| case ICMPV6_MOBILE_PREFIX_ADV: |
| break; |
| |
| default: |
| /* informational */ |
| if (type & ICMPV6_INFOMSG_MASK) |
| break; |
| |
| net_dbg_ratelimited("icmpv6: msg of unknown type [%pI6c > %pI6c]\n", |
| saddr, daddr); |
| |
| /* |
| * error of unknown type. |
| * must pass to upper level |
| */ |
| |
| icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); |
| } |
| |
| /* until the v6 path can be better sorted assume failure and |
| * preserve the status quo behaviour for the rest of the paths to here |
| */ |
| if (success) |
| consume_skb(skb); |
| else |
| kfree_skb(skb); |
| |
| return 0; |
| |
| csum_error: |
| __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_CSUMERRORS); |
| discard_it: |
| __ICMP6_INC_STATS(dev_net(dev), idev, ICMP6_MIB_INERRORS); |
| drop_no_count: |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| void icmpv6_flow_init(struct sock *sk, struct flowi6 *fl6, |
| u8 type, |
| const struct in6_addr *saddr, |
| const struct in6_addr *daddr, |
| int oif) |
| { |
| memset(fl6, 0, sizeof(*fl6)); |
| fl6->saddr = *saddr; |
| fl6->daddr = *daddr; |
| fl6->flowi6_proto = IPPROTO_ICMPV6; |
| fl6->fl6_icmp_type = type; |
| fl6->fl6_icmp_code = 0; |
| fl6->flowi6_oif = oif; |
| security_sk_classify_flow(sk, flowi6_to_flowi(fl6)); |
| } |
| |
| static void __net_exit icmpv6_sk_exit(struct net *net) |
| { |
| int i; |
| |
| for_each_possible_cpu(i) |
| inet_ctl_sock_destroy(*per_cpu_ptr(net->ipv6.icmp_sk, i)); |
| free_percpu(net->ipv6.icmp_sk); |
| } |
| |
| static int __net_init icmpv6_sk_init(struct net *net) |
| { |
| struct sock *sk; |
| int err, i; |
| |
| net->ipv6.icmp_sk = alloc_percpu(struct sock *); |
| if (!net->ipv6.icmp_sk) |
| return -ENOMEM; |
| |
| for_each_possible_cpu(i) { |
| err = inet_ctl_sock_create(&sk, PF_INET6, |
| SOCK_RAW, IPPROTO_ICMPV6, net); |
| if (err < 0) { |
| pr_err("Failed to initialize the ICMP6 control socket (err %d)\n", |
| err); |
| goto fail; |
| } |
| |
| *per_cpu_ptr(net->ipv6.icmp_sk, i) = sk; |
| |
| /* Enough space for 2 64K ICMP packets, including |
| * sk_buff struct overhead. |
| */ |
| sk->sk_sndbuf = 2 * SKB_TRUESIZE(64 * 1024); |
| } |
| return 0; |
| |
| fail: |
| icmpv6_sk_exit(net); |
| return err; |
| } |
| |
| static struct pernet_operations icmpv6_sk_ops = { |
| .init = icmpv6_sk_init, |
| .exit = icmpv6_sk_exit, |
| }; |
| |
| int __init icmpv6_init(void) |
| { |
| int err; |
| |
| err = register_pernet_subsys(&icmpv6_sk_ops); |
| if (err < 0) |
| return err; |
| |
| err = -EAGAIN; |
| if (inet6_add_protocol(&icmpv6_protocol, IPPROTO_ICMPV6) < 0) |
| goto fail; |
| |
| err = inet6_register_icmp_sender(icmp6_send); |
| if (err) |
| goto sender_reg_err; |
| return 0; |
| |
| sender_reg_err: |
| inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
| fail: |
| pr_err("Failed to register ICMP6 protocol\n"); |
| unregister_pernet_subsys(&icmpv6_sk_ops); |
| return err; |
| } |
| |
| void icmpv6_cleanup(void) |
| { |
| inet6_unregister_icmp_sender(icmp6_send); |
| unregister_pernet_subsys(&icmpv6_sk_ops); |
| inet6_del_protocol(&icmpv6_protocol, IPPROTO_ICMPV6); |
| } |
| |
| |
| static const struct icmp6_err { |
| int err; |
| int fatal; |
| } tab_unreach[] = { |
| { /* NOROUTE */ |
| .err = ENETUNREACH, |
| .fatal = 0, |
| }, |
| { /* ADM_PROHIBITED */ |
| .err = EACCES, |
| .fatal = 1, |
| }, |
| { /* Was NOT_NEIGHBOUR, now reserved */ |
| .err = EHOSTUNREACH, |
| .fatal = 0, |
| }, |
| { /* ADDR_UNREACH */ |
| .err = EHOSTUNREACH, |
| .fatal = 0, |
| }, |
| { /* PORT_UNREACH */ |
| .err = ECONNREFUSED, |
| .fatal = 1, |
| }, |
| { /* POLICY_FAIL */ |
| .err = EACCES, |
| .fatal = 1, |
| }, |
| { /* REJECT_ROUTE */ |
| .err = EACCES, |
| .fatal = 1, |
| }, |
| }; |
| |
| int icmpv6_err_convert(u8 type, u8 code, int *err) |
| { |
| int fatal = 0; |
| |
| *err = EPROTO; |
| |
| switch (type) { |
| case ICMPV6_DEST_UNREACH: |
| fatal = 1; |
| if (code < ARRAY_SIZE(tab_unreach)) { |
| *err = tab_unreach[code].err; |
| fatal = tab_unreach[code].fatal; |
| } |
| break; |
| |
| case ICMPV6_PKT_TOOBIG: |
| *err = EMSGSIZE; |
| break; |
| |
| case ICMPV6_PARAMPROB: |
| *err = EPROTO; |
| fatal = 1; |
| break; |
| |
| case ICMPV6_TIME_EXCEED: |
| *err = EHOSTUNREACH; |
| break; |
| } |
| |
| return fatal; |
| } |
| EXPORT_SYMBOL(icmpv6_err_convert); |
| |
| #ifdef CONFIG_SYSCTL |
| static struct ctl_table ipv6_icmp_table_template[] = { |
| { |
| .procname = "ratelimit", |
| .data = &init_net.ipv6.sysctl.icmpv6_time, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec_ms_jiffies, |
| }, |
| { |
| .procname = "echo_ignore_all", |
| .data = &init_net.ipv6.sysctl.icmpv6_echo_ignore_all, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { }, |
| }; |
| |
| struct ctl_table * __net_init ipv6_icmp_sysctl_init(struct net *net) |
| { |
| struct ctl_table *table; |
| |
| table = kmemdup(ipv6_icmp_table_template, |
| sizeof(ipv6_icmp_table_template), |
| GFP_KERNEL); |
| |
| if (table) { |
| table[0].data = &net->ipv6.sysctl.icmpv6_time; |
| table[1].data = &net->ipv6.sysctl.icmpv6_echo_ignore_all; |
| } |
| return table; |
| } |
| #endif |