| /* |
| * IPv6 output functions |
| * Linux INET6 implementation |
| * |
| * Authors: |
| * Pedro Roque <roque@di.fc.ul.pt> |
| * |
| * Based on linux/net/ipv4/ip_output.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. |
| * |
| * Changes: |
| * A.N.Kuznetsov : airthmetics in fragmentation. |
| * extension headers are implemented. |
| * route changes now work. |
| * ip6_forward does not confuse sniffers. |
| * etc. |
| * |
| * H. von Brand : Added missing #include <linux/string.h> |
| * Imran Patel : frag id should be in NBO |
| * Kazunori MIYAZAWA @USAGI |
| * : add ip6_append_data and related functions |
| * for datagram xmit |
| */ |
| |
| #include <linux/errno.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/socket.h> |
| #include <linux/net.h> |
| #include <linux/netdevice.h> |
| #include <linux/if_arp.h> |
| #include <linux/in6.h> |
| #include <linux/tcp.h> |
| #include <linux/route.h> |
| #include <linux/module.h> |
| #include <linux/slab.h> |
| |
| #include <linux/bpf-cgroup.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter_ipv6.h> |
| |
| #include <net/sock.h> |
| #include <net/snmp.h> |
| |
| #include <net/ipv6.h> |
| #include <net/ndisc.h> |
| #include <net/protocol.h> |
| #include <net/ip6_route.h> |
| #include <net/addrconf.h> |
| #include <net/rawv6.h> |
| #include <net/icmp.h> |
| #include <net/xfrm.h> |
| #include <net/checksum.h> |
| #include <linux/mroute6.h> |
| #include <net/l3mdev.h> |
| #include <net/lwtunnel.h> |
| |
| static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff *skb) |
| { |
| struct dst_entry *dst = skb_dst(skb); |
| struct net_device *dev = dst->dev; |
| struct neighbour *neigh; |
| struct in6_addr *nexthop; |
| int ret; |
| |
| if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { |
| struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| |
| if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(sk) && |
| ((mroute6_is_socket(net, skb) && |
| !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) || |
| ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr, |
| &ipv6_hdr(skb)->saddr))) { |
| struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC); |
| |
| /* Do not check for IFF_ALLMULTI; multicast routing |
| is not supported in any case. |
| */ |
| if (newskb) |
| NF_HOOK(NFPROTO_IPV6, NF_INET_POST_ROUTING, |
| net, sk, newskb, NULL, newskb->dev, |
| dev_loopback_xmit); |
| |
| if (ipv6_hdr(skb)->hop_limit == 0) { |
| IP6_INC_STATS(net, idev, |
| IPSTATS_MIB_OUTDISCARDS); |
| kfree_skb(skb); |
| return 0; |
| } |
| } |
| |
| IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, skb->len); |
| |
| if (IPV6_ADDR_MC_SCOPE(&ipv6_hdr(skb)->daddr) <= |
| IPV6_ADDR_SCOPE_NODELOCAL && |
| !(dev->flags & IFF_LOOPBACK)) { |
| kfree_skb(skb); |
| return 0; |
| } |
| } |
| |
| if (lwtunnel_xmit_redirect(dst->lwtstate)) { |
| int res = lwtunnel_xmit(skb); |
| |
| if (res < 0 || res == LWTUNNEL_XMIT_DONE) |
| return res; |
| } |
| |
| rcu_read_lock_bh(); |
| nexthop = rt6_nexthop((struct rt6_info *)dst, &ipv6_hdr(skb)->daddr); |
| neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop); |
| if (unlikely(!neigh)) |
| neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false); |
| if (!IS_ERR(neigh)) { |
| sock_confirm_neigh(skb, neigh); |
| ret = neigh_output(neigh, skb, false); |
| rcu_read_unlock_bh(); |
| return ret; |
| } |
| rcu_read_unlock_bh(); |
| |
| IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| static int ip6_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
| { |
| int ret; |
| |
| ret = BPF_CGROUP_RUN_PROG_INET_EGRESS(sk, skb); |
| if (ret) { |
| kfree_skb(skb); |
| return ret; |
| } |
| |
| #if defined(CONFIG_NETFILTER) && defined(CONFIG_XFRM) |
| /* Policy lookup after SNAT yielded a new policy */ |
| if (skb_dst(skb)->xfrm) { |
| IPCB(skb)->flags |= IPSKB_REROUTED; |
| return dst_output(net, sk, skb); |
| } |
| #endif |
| |
| if ((skb->len > ip6_skb_dst_mtu(skb) && !skb_is_gso(skb)) || |
| dst_allfrag(skb_dst(skb)) || |
| (IP6CB(skb)->frag_max_size && skb->len > IP6CB(skb)->frag_max_size)) |
| return ip6_fragment(net, sk, skb, ip6_finish_output2); |
| else |
| return ip6_finish_output2(net, sk, skb); |
| } |
| |
| int ip6_output(struct net *net, struct sock *sk, struct sk_buff *skb) |
| { |
| struct net_device *dev = skb_dst(skb)->dev; |
| struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| |
| skb->protocol = htons(ETH_P_IPV6); |
| skb->dev = dev; |
| |
| if (unlikely(idev->cnf.disable_ipv6)) { |
| IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS); |
| kfree_skb(skb); |
| return 0; |
| } |
| |
| return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING, |
| net, sk, skb, NULL, dev, |
| ip6_finish_output, |
| !(IP6CB(skb)->flags & IP6SKB_REROUTED)); |
| } |
| |
| bool ip6_autoflowlabel(struct net *net, const struct ipv6_pinfo *np) |
| { |
| if (!np->autoflowlabel_set) |
| return ip6_default_np_autolabel(net); |
| else |
| return np->autoflowlabel; |
| } |
| |
| /* |
| * xmit an sk_buff (used by TCP, SCTP and DCCP) |
| * Note : socket lock is not held for SYNACK packets, but might be modified |
| * by calls to skb_set_owner_w() and ipv6_local_error(), |
| * which are using proper atomic operations or spinlocks. |
| */ |
| int ip6_xmit(const struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6, |
| __u32 mark, struct ipv6_txoptions *opt, int tclass) |
| { |
| struct net *net = sock_net(sk); |
| const struct ipv6_pinfo *np = inet6_sk(sk); |
| struct in6_addr *first_hop = &fl6->daddr; |
| struct dst_entry *dst = skb_dst(skb); |
| unsigned int head_room; |
| struct ipv6hdr *hdr; |
| u8 proto = fl6->flowi6_proto; |
| int seg_len = skb->len; |
| int hlimit = -1; |
| u32 mtu; |
| |
| head_room = sizeof(struct ipv6hdr) + LL_RESERVED_SPACE(dst->dev); |
| if (opt) |
| head_room += opt->opt_nflen + opt->opt_flen; |
| |
| if (unlikely(skb_headroom(skb) < head_room)) { |
| struct sk_buff *skb2 = skb_realloc_headroom(skb, head_room); |
| if (!skb2) { |
| IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_OUTDISCARDS); |
| kfree_skb(skb); |
| return -ENOBUFS; |
| } |
| if (skb->sk) |
| skb_set_owner_w(skb2, skb->sk); |
| consume_skb(skb); |
| skb = skb2; |
| } |
| |
| if (opt) { |
| seg_len += opt->opt_nflen + opt->opt_flen; |
| |
| if (opt->opt_flen) |
| ipv6_push_frag_opts(skb, opt, &proto); |
| |
| if (opt->opt_nflen) |
| ipv6_push_nfrag_opts(skb, opt, &proto, &first_hop, |
| &fl6->saddr); |
| } |
| |
| skb_push(skb, sizeof(struct ipv6hdr)); |
| skb_reset_network_header(skb); |
| hdr = ipv6_hdr(skb); |
| |
| /* |
| * Fill in the IPv6 header |
| */ |
| if (np) |
| hlimit = np->hop_limit; |
| if (hlimit < 0) |
| hlimit = ip6_dst_hoplimit(dst); |
| |
| ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel, |
| ip6_autoflowlabel(net, np), fl6)); |
| |
| hdr->payload_len = htons(seg_len); |
| hdr->nexthdr = proto; |
| hdr->hop_limit = hlimit; |
| |
| hdr->saddr = fl6->saddr; |
| hdr->daddr = *first_hop; |
| |
| skb->protocol = htons(ETH_P_IPV6); |
| skb->priority = sk->sk_priority; |
| skb->mark = mark; |
| |
| mtu = dst_mtu(dst); |
| if ((skb->len <= mtu) || skb->ignore_df || skb_is_gso(skb)) { |
| IP6_UPD_PO_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_OUT, skb->len); |
| |
| /* if egress device is enslaved to an L3 master device pass the |
| * skb to its handler for processing |
| */ |
| skb = l3mdev_ip6_out((struct sock *)sk, skb); |
| if (unlikely(!skb)) |
| return 0; |
| |
| /* hooks should never assume socket lock is held. |
| * we promote our socket to non const |
| */ |
| return NF_HOOK(NFPROTO_IPV6, NF_INET_LOCAL_OUT, |
| net, (struct sock *)sk, skb, NULL, dst->dev, |
| dst_output); |
| } |
| |
| skb->dev = dst->dev; |
| /* ipv6_local_error() does not require socket lock, |
| * we promote our socket to non const |
| */ |
| ipv6_local_error((struct sock *)sk, EMSGSIZE, fl6, mtu); |
| |
| IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), IPSTATS_MIB_FRAGFAILS); |
| kfree_skb(skb); |
| return -EMSGSIZE; |
| } |
| EXPORT_SYMBOL(ip6_xmit); |
| |
| static int ip6_call_ra_chain(struct sk_buff *skb, int sel) |
| { |
| struct ip6_ra_chain *ra; |
| struct sock *last = NULL; |
| |
| read_lock(&ip6_ra_lock); |
| for (ra = ip6_ra_chain; ra; ra = ra->next) { |
| struct sock *sk = ra->sk; |
| if (sk && ra->sel == sel && |
| (!sk->sk_bound_dev_if || |
| sk->sk_bound_dev_if == skb->dev->ifindex)) { |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| |
| if (np && np->rtalert_isolate && |
| !net_eq(sock_net(sk), dev_net(skb->dev))) { |
| continue; |
| } |
| if (last) { |
| struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC); |
| if (skb2) |
| rawv6_rcv(last, skb2); |
| } |
| last = sk; |
| } |
| } |
| |
| if (last) { |
| rawv6_rcv(last, skb); |
| read_unlock(&ip6_ra_lock); |
| return 1; |
| } |
| read_unlock(&ip6_ra_lock); |
| return 0; |
| } |
| |
| static int ip6_forward_proxy_check(struct sk_buff *skb) |
| { |
| struct ipv6hdr *hdr = ipv6_hdr(skb); |
| u8 nexthdr = hdr->nexthdr; |
| __be16 frag_off; |
| int offset; |
| |
| if (ipv6_ext_hdr(nexthdr)) { |
| offset = ipv6_skip_exthdr(skb, sizeof(*hdr), &nexthdr, &frag_off); |
| if (offset < 0) |
| return 0; |
| } else |
| offset = sizeof(struct ipv6hdr); |
| |
| if (nexthdr == IPPROTO_ICMPV6) { |
| struct icmp6hdr *icmp6; |
| |
| if (!pskb_may_pull(skb, (skb_network_header(skb) + |
| offset + 1 - skb->data))) |
| return 0; |
| |
| icmp6 = (struct icmp6hdr *)(skb_network_header(skb) + offset); |
| |
| switch (icmp6->icmp6_type) { |
| case NDISC_ROUTER_SOLICITATION: |
| case NDISC_ROUTER_ADVERTISEMENT: |
| case NDISC_NEIGHBOUR_SOLICITATION: |
| case NDISC_NEIGHBOUR_ADVERTISEMENT: |
| case NDISC_REDIRECT: |
| /* For reaction involving unicast neighbor discovery |
| * message destined to the proxied address, pass it to |
| * input function. |
| */ |
| return 1; |
| default: |
| break; |
| } |
| } |
| |
| /* |
| * The proxying router can't forward traffic sent to a link-local |
| * address, so signal the sender and discard the packet. This |
| * behavior is clarified by the MIPv6 specification. |
| */ |
| if (ipv6_addr_type(&hdr->daddr) & IPV6_ADDR_LINKLOCAL) { |
| dst_link_failure(skb); |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| static inline int ip6_forward_finish(struct net *net, struct sock *sk, |
| struct sk_buff *skb) |
| { |
| struct dst_entry *dst = skb_dst(skb); |
| |
| __IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTFORWDATAGRAMS); |
| __IP6_ADD_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTOCTETS, skb->len); |
| |
| #ifdef CONFIG_NET_SWITCHDEV |
| if (skb->offload_l3_fwd_mark) { |
| consume_skb(skb); |
| return 0; |
| } |
| #endif |
| |
| skb->tstamp = 0; |
| return dst_output(net, sk, skb); |
| } |
| |
| static bool ip6_pkt_too_big(const struct sk_buff *skb, unsigned int mtu) |
| { |
| if (skb->len <= mtu) |
| return false; |
| |
| /* ipv6 conntrack defrag sets max_frag_size + ignore_df */ |
| if (IP6CB(skb)->frag_max_size && IP6CB(skb)->frag_max_size > mtu) |
| return true; |
| |
| if (skb->ignore_df) |
| return false; |
| |
| if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu)) |
| return false; |
| |
| return true; |
| } |
| |
| int ip6_forward(struct sk_buff *skb) |
| { |
| struct inet6_dev *idev = __in6_dev_get_safely(skb->dev); |
| struct dst_entry *dst = skb_dst(skb); |
| struct ipv6hdr *hdr = ipv6_hdr(skb); |
| struct inet6_skb_parm *opt = IP6CB(skb); |
| struct net *net = dev_net(dst->dev); |
| u32 mtu; |
| |
| if (net->ipv6.devconf_all->forwarding == 0) |
| goto error; |
| |
| if (skb->pkt_type != PACKET_HOST) |
| goto drop; |
| |
| if (unlikely(skb->sk)) |
| goto drop; |
| |
| if (skb_warn_if_lro(skb)) |
| goto drop; |
| |
| if (!xfrm6_policy_check(NULL, XFRM_POLICY_FWD, skb)) { |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); |
| goto drop; |
| } |
| |
| skb_forward_csum(skb); |
| |
| /* |
| * We DO NOT make any processing on |
| * RA packets, pushing them to user level AS IS |
| * without ane WARRANTY that application will be able |
| * to interpret them. The reason is that we |
| * cannot make anything clever here. |
| * |
| * We are not end-node, so that if packet contains |
| * AH/ESP, we cannot make anything. |
| * Defragmentation also would be mistake, RA packets |
| * cannot be fragmented, because there is no warranty |
| * that different fragments will go along one path. --ANK |
| */ |
| if (unlikely(opt->flags & IP6SKB_ROUTERALERT)) { |
| if (ip6_call_ra_chain(skb, ntohs(opt->ra))) |
| return 0; |
| } |
| |
| /* |
| * check and decrement ttl |
| */ |
| if (hdr->hop_limit <= 1) { |
| /* Force OUTPUT device used as source address */ |
| skb->dev = dst->dev; |
| icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT, 0); |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS); |
| |
| kfree_skb(skb); |
| return -ETIMEDOUT; |
| } |
| |
| /* XXX: idev->cnf.proxy_ndp? */ |
| if (net->ipv6.devconf_all->proxy_ndp && |
| pneigh_lookup(&nd_tbl, net, &hdr->daddr, skb->dev, 0)) { |
| int proxied = ip6_forward_proxy_check(skb); |
| if (proxied > 0) |
| return ip6_input(skb); |
| else if (proxied < 0) { |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); |
| goto drop; |
| } |
| } |
| |
| if (!xfrm6_route_forward(skb)) { |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INDISCARDS); |
| goto drop; |
| } |
| dst = skb_dst(skb); |
| |
| /* IPv6 specs say nothing about it, but it is clear that we cannot |
| send redirects to source routed frames. |
| We don't send redirects to frames decapsulated from IPsec. |
| */ |
| if (IP6CB(skb)->iif == dst->dev->ifindex && |
| opt->srcrt == 0 && !skb_sec_path(skb)) { |
| struct in6_addr *target = NULL; |
| struct inet_peer *peer; |
| struct rt6_info *rt; |
| |
| /* |
| * incoming and outgoing devices are the same |
| * send a redirect. |
| */ |
| |
| rt = (struct rt6_info *) dst; |
| if (rt->rt6i_flags & RTF_GATEWAY) |
| target = &rt->rt6i_gateway; |
| else |
| target = &hdr->daddr; |
| |
| peer = inet_getpeer_v6(net->ipv6.peers, &hdr->daddr, 1); |
| |
| /* Limit redirects both by destination (here) |
| and by source (inside ndisc_send_redirect) |
| */ |
| if (inet_peer_xrlim_allow(peer, 1*HZ)) |
| ndisc_send_redirect(skb, target); |
| if (peer) |
| inet_putpeer(peer); |
| } else { |
| int addrtype = ipv6_addr_type(&hdr->saddr); |
| |
| /* This check is security critical. */ |
| if (addrtype == IPV6_ADDR_ANY || |
| addrtype & (IPV6_ADDR_MULTICAST | IPV6_ADDR_LOOPBACK)) |
| goto error; |
| if (addrtype & IPV6_ADDR_LINKLOCAL) { |
| icmpv6_send(skb, ICMPV6_DEST_UNREACH, |
| ICMPV6_NOT_NEIGHBOUR, 0); |
| goto error; |
| } |
| } |
| |
| mtu = ip6_dst_mtu_forward(dst); |
| if (mtu < IPV6_MIN_MTU) |
| mtu = IPV6_MIN_MTU; |
| |
| if (ip6_pkt_too_big(skb, mtu)) { |
| /* Again, force OUTPUT device used as source address */ |
| skb->dev = dst->dev; |
| icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INTOOBIGERRORS); |
| __IP6_INC_STATS(net, ip6_dst_idev(dst), |
| IPSTATS_MIB_FRAGFAILS); |
| kfree_skb(skb); |
| return -EMSGSIZE; |
| } |
| |
| if (skb_cow(skb, dst->dev->hard_header_len)) { |
| __IP6_INC_STATS(net, ip6_dst_idev(dst), |
| IPSTATS_MIB_OUTDISCARDS); |
| goto drop; |
| } |
| |
| hdr = ipv6_hdr(skb); |
| |
| /* Mangling hops number delayed to point after skb COW */ |
| |
| hdr->hop_limit--; |
| |
| return NF_HOOK(NFPROTO_IPV6, NF_INET_FORWARD, |
| net, NULL, skb, skb->dev, dst->dev, |
| ip6_forward_finish); |
| |
| error: |
| __IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); |
| drop: |
| kfree_skb(skb); |
| return -EINVAL; |
| } |
| |
| static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) |
| { |
| to->pkt_type = from->pkt_type; |
| to->priority = from->priority; |
| to->protocol = from->protocol; |
| skb_dst_drop(to); |
| skb_dst_set(to, dst_clone(skb_dst(from))); |
| to->dev = from->dev; |
| to->mark = from->mark; |
| |
| skb_copy_hash(to, from); |
| |
| #ifdef CONFIG_NET_SCHED |
| to->tc_index = from->tc_index; |
| #endif |
| nf_copy(to, from); |
| skb_ext_copy(to, from); |
| skb_copy_secmark(to, from); |
| } |
| |
| int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, |
| int (*output)(struct net *, struct sock *, struct sk_buff *)) |
| { |
| struct sk_buff *frag; |
| struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); |
| struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? |
| inet6_sk(skb->sk) : NULL; |
| struct ipv6hdr *tmp_hdr; |
| struct frag_hdr *fh; |
| unsigned int mtu, hlen, left, len, nexthdr_offset; |
| int hroom, troom; |
| __be32 frag_id; |
| int ptr, offset = 0, err = 0; |
| u8 *prevhdr, nexthdr = 0; |
| |
| err = ip6_find_1stfragopt(skb, &prevhdr); |
| if (err < 0) |
| goto fail; |
| hlen = err; |
| nexthdr = *prevhdr; |
| nexthdr_offset = prevhdr - skb_network_header(skb); |
| |
| mtu = ip6_skb_dst_mtu(skb); |
| |
| /* We must not fragment if the socket is set to force MTU discovery |
| * or if the skb it not generated by a local socket. |
| */ |
| if (unlikely(!skb->ignore_df && skb->len > mtu)) |
| goto fail_toobig; |
| |
| if (IP6CB(skb)->frag_max_size) { |
| if (IP6CB(skb)->frag_max_size > mtu) |
| goto fail_toobig; |
| |
| /* don't send fragments larger than what we received */ |
| mtu = IP6CB(skb)->frag_max_size; |
| if (mtu < IPV6_MIN_MTU) |
| mtu = IPV6_MIN_MTU; |
| } |
| |
| if (np && np->frag_size < mtu) { |
| if (np->frag_size) |
| mtu = np->frag_size; |
| } |
| if (mtu < hlen + sizeof(struct frag_hdr) + 8) |
| goto fail_toobig; |
| mtu -= hlen + sizeof(struct frag_hdr); |
| |
| frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, |
| &ipv6_hdr(skb)->saddr); |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL && |
| (err = skb_checksum_help(skb))) |
| goto fail; |
| |
| prevhdr = skb_network_header(skb) + nexthdr_offset; |
| hroom = LL_RESERVED_SPACE(rt->dst.dev); |
| if (skb_has_frag_list(skb)) { |
| unsigned int first_len = skb_pagelen(skb); |
| struct sk_buff *frag2; |
| |
| if (first_len - hlen > mtu || |
| ((first_len - hlen) & 7) || |
| skb_cloned(skb) || |
| skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) |
| goto slow_path; |
| |
| skb_walk_frags(skb, frag) { |
| /* Correct geometry. */ |
| if (frag->len > mtu || |
| ((frag->len & 7) && frag->next) || |
| skb_headroom(frag) < (hlen + hroom + sizeof(struct frag_hdr))) |
| goto slow_path_clean; |
| |
| /* Partially cloned skb? */ |
| if (skb_shared(frag)) |
| goto slow_path_clean; |
| |
| BUG_ON(frag->sk); |
| if (skb->sk) { |
| frag->sk = skb->sk; |
| frag->destructor = sock_wfree; |
| } |
| skb->truesize -= frag->truesize; |
| } |
| |
| err = 0; |
| offset = 0; |
| /* BUILD HEADER */ |
| |
| *prevhdr = NEXTHDR_FRAGMENT; |
| tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); |
| if (!tmp_hdr) { |
| err = -ENOMEM; |
| goto fail; |
| } |
| frag = skb_shinfo(skb)->frag_list; |
| skb_frag_list_init(skb); |
| |
| __skb_pull(skb, hlen); |
| fh = __skb_push(skb, sizeof(struct frag_hdr)); |
| __skb_push(skb, hlen); |
| skb_reset_network_header(skb); |
| memcpy(skb_network_header(skb), tmp_hdr, hlen); |
| |
| fh->nexthdr = nexthdr; |
| fh->reserved = 0; |
| fh->frag_off = htons(IP6_MF); |
| fh->identification = frag_id; |
| |
| first_len = skb_pagelen(skb); |
| skb->data_len = first_len - skb_headlen(skb); |
| skb->len = first_len; |
| ipv6_hdr(skb)->payload_len = htons(first_len - |
| sizeof(struct ipv6hdr)); |
| |
| for (;;) { |
| /* Prepare header of the next frame, |
| * before previous one went down. */ |
| if (frag) { |
| frag->ip_summed = CHECKSUM_NONE; |
| skb_reset_transport_header(frag); |
| fh = __skb_push(frag, sizeof(struct frag_hdr)); |
| __skb_push(frag, hlen); |
| skb_reset_network_header(frag); |
| memcpy(skb_network_header(frag), tmp_hdr, |
| hlen); |
| offset += skb->len - hlen - sizeof(struct frag_hdr); |
| fh->nexthdr = nexthdr; |
| fh->reserved = 0; |
| fh->frag_off = htons(offset); |
| if (frag->next) |
| fh->frag_off |= htons(IP6_MF); |
| fh->identification = frag_id; |
| ipv6_hdr(frag)->payload_len = |
| htons(frag->len - |
| sizeof(struct ipv6hdr)); |
| ip6_copy_metadata(frag, skb); |
| } |
| |
| err = output(net, sk, skb); |
| if (!err) |
| IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| IPSTATS_MIB_FRAGCREATES); |
| |
| if (err || !frag) |
| break; |
| |
| skb = frag; |
| frag = skb->next; |
| skb_mark_not_on_list(skb); |
| } |
| |
| kfree(tmp_hdr); |
| |
| if (err == 0) { |
| IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| IPSTATS_MIB_FRAGOKS); |
| return 0; |
| } |
| |
| kfree_skb_list(frag); |
| |
| IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), |
| IPSTATS_MIB_FRAGFAILS); |
| return err; |
| |
| slow_path_clean: |
| skb_walk_frags(skb, frag2) { |
| if (frag2 == frag) |
| break; |
| frag2->sk = NULL; |
| frag2->destructor = NULL; |
| skb->truesize += frag2->truesize; |
| } |
| } |
| |
| slow_path: |
| left = skb->len - hlen; /* Space per frame */ |
| ptr = hlen; /* Where to start from */ |
| |
| /* |
| * Fragment the datagram. |
| */ |
| |
| troom = rt->dst.dev->needed_tailroom; |
| |
| /* |
| * Keep copying data until we run out. |
| */ |
| while (left > 0) { |
| u8 *fragnexthdr_offset; |
| |
| len = left; |
| /* IF: it doesn't fit, use 'mtu' - the data space left */ |
| if (len > mtu) |
| len = mtu; |
| /* IF: we are not sending up to and including the packet end |
| then align the next start on an eight byte boundary */ |
| if (len < left) { |
| len &= ~7; |
| } |
| |
| /* Allocate buffer */ |
| frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + |
| hroom + troom, GFP_ATOMIC); |
| if (!frag) { |
| err = -ENOMEM; |
| goto fail; |
| } |
| |
| /* |
| * Set up data on packet |
| */ |
| |
| ip6_copy_metadata(frag, skb); |
| skb_reserve(frag, hroom); |
| skb_put(frag, len + hlen + sizeof(struct frag_hdr)); |
| skb_reset_network_header(frag); |
| fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); |
| frag->transport_header = (frag->network_header + hlen + |
| sizeof(struct frag_hdr)); |
| |
| /* |
| * Charge the memory for the fragment to any owner |
| * it might possess |
| */ |
| if (skb->sk) |
| skb_set_owner_w(frag, skb->sk); |
| |
| /* |
| * Copy the packet header into the new buffer. |
| */ |
| skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); |
| |
| fragnexthdr_offset = skb_network_header(frag); |
| fragnexthdr_offset += prevhdr - skb_network_header(skb); |
| *fragnexthdr_offset = NEXTHDR_FRAGMENT; |
| |
| /* |
| * Build fragment header. |
| */ |
| fh->nexthdr = nexthdr; |
| fh->reserved = 0; |
| fh->identification = frag_id; |
| |
| /* |
| * Copy a block of the IP datagram. |
| */ |
| BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag), |
| len)); |
| left -= len; |
| |
| fh->frag_off = htons(offset); |
| if (left > 0) |
| fh->frag_off |= htons(IP6_MF); |
| ipv6_hdr(frag)->payload_len = htons(frag->len - |
| sizeof(struct ipv6hdr)); |
| |
| ptr += len; |
| offset += len; |
| |
| /* |
| * Put this fragment into the sending queue. |
| */ |
| err = output(net, sk, frag); |
| if (err) |
| goto fail; |
| |
| IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_FRAGCREATES); |
| } |
| IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_FRAGOKS); |
| consume_skb(skb); |
| return err; |
| |
| fail_toobig: |
| if (skb->sk && dst_allfrag(skb_dst(skb))) |
| sk_nocaps_add(skb->sk, NETIF_F_GSO_MASK); |
| |
| icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu); |
| err = -EMSGSIZE; |
| |
| fail: |
| IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_FRAGFAILS); |
| kfree_skb(skb); |
| return err; |
| } |
| |
| static inline int ip6_rt_check(const struct rt6key *rt_key, |
| const struct in6_addr *fl_addr, |
| const struct in6_addr *addr_cache) |
| { |
| return (rt_key->plen != 128 || !ipv6_addr_equal(fl_addr, &rt_key->addr)) && |
| (!addr_cache || !ipv6_addr_equal(fl_addr, addr_cache)); |
| } |
| |
| static struct dst_entry *ip6_sk_dst_check(struct sock *sk, |
| struct dst_entry *dst, |
| const struct flowi6 *fl6) |
| { |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| struct rt6_info *rt; |
| |
| if (!dst) |
| goto out; |
| |
| if (dst->ops->family != AF_INET6) { |
| dst_release(dst); |
| return NULL; |
| } |
| |
| rt = (struct rt6_info *)dst; |
| /* Yes, checking route validity in not connected |
| * case is not very simple. Take into account, |
| * that we do not support routing by source, TOS, |
| * and MSG_DONTROUTE --ANK (980726) |
| * |
| * 1. ip6_rt_check(): If route was host route, |
| * check that cached destination is current. |
| * If it is network route, we still may |
| * check its validity using saved pointer |
| * to the last used address: daddr_cache. |
| * We do not want to save whole address now, |
| * (because main consumer of this service |
| * is tcp, which has not this problem), |
| * so that the last trick works only on connected |
| * sockets. |
| * 2. oif also should be the same. |
| */ |
| if (ip6_rt_check(&rt->rt6i_dst, &fl6->daddr, np->daddr_cache) || |
| #ifdef CONFIG_IPV6_SUBTREES |
| ip6_rt_check(&rt->rt6i_src, &fl6->saddr, np->saddr_cache) || |
| #endif |
| (!(fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) && |
| (fl6->flowi6_oif && fl6->flowi6_oif != dst->dev->ifindex))) { |
| dst_release(dst); |
| dst = NULL; |
| } |
| |
| out: |
| return dst; |
| } |
| |
| static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, |
| struct dst_entry **dst, struct flowi6 *fl6) |
| { |
| #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
| struct neighbour *n; |
| struct rt6_info *rt; |
| #endif |
| int err; |
| int flags = 0; |
| |
| /* The correct way to handle this would be to do |
| * ip6_route_get_saddr, and then ip6_route_output; however, |
| * the route-specific preferred source forces the |
| * ip6_route_output call _before_ ip6_route_get_saddr. |
| * |
| * In source specific routing (no src=any default route), |
| * ip6_route_output will fail given src=any saddr, though, so |
| * that's why we try it again later. |
| */ |
| if (ipv6_addr_any(&fl6->saddr) && (!*dst || !(*dst)->error)) { |
| struct fib6_info *from; |
| struct rt6_info *rt; |
| bool had_dst = *dst != NULL; |
| |
| if (!had_dst) |
| *dst = ip6_route_output(net, sk, fl6); |
| rt = (*dst)->error ? NULL : (struct rt6_info *)*dst; |
| |
| rcu_read_lock(); |
| from = rt ? rcu_dereference(rt->from) : NULL; |
| err = ip6_route_get_saddr(net, from, &fl6->daddr, |
| sk ? inet6_sk(sk)->srcprefs : 0, |
| &fl6->saddr); |
| rcu_read_unlock(); |
| |
| if (err) |
| goto out_err_release; |
| |
| /* If we had an erroneous initial result, pretend it |
| * never existed and let the SA-enabled version take |
| * over. |
| */ |
| if (!had_dst && (*dst)->error) { |
| dst_release(*dst); |
| *dst = NULL; |
| } |
| |
| if (fl6->flowi6_oif) |
| flags |= RT6_LOOKUP_F_IFACE; |
| } |
| |
| if (!*dst) |
| *dst = ip6_route_output_flags(net, sk, fl6, flags); |
| |
| err = (*dst)->error; |
| if (err) |
| goto out_err_release; |
| |
| #ifdef CONFIG_IPV6_OPTIMISTIC_DAD |
| /* |
| * Here if the dst entry we've looked up |
| * has a neighbour entry that is in the INCOMPLETE |
| * state and the src address from the flow is |
| * marked as OPTIMISTIC, we release the found |
| * dst entry and replace it instead with the |
| * dst entry of the nexthop router |
| */ |
| rt = (struct rt6_info *) *dst; |
| rcu_read_lock_bh(); |
| n = __ipv6_neigh_lookup_noref(rt->dst.dev, |
| rt6_nexthop(rt, &fl6->daddr)); |
| err = n && !(n->nud_state & NUD_VALID) ? -EINVAL : 0; |
| rcu_read_unlock_bh(); |
| |
| if (err) { |
| struct inet6_ifaddr *ifp; |
| struct flowi6 fl_gw6; |
| int redirect; |
| |
| ifp = ipv6_get_ifaddr(net, &fl6->saddr, |
| (*dst)->dev, 1); |
| |
| redirect = (ifp && ifp->flags & IFA_F_OPTIMISTIC); |
| if (ifp) |
| in6_ifa_put(ifp); |
| |
| if (redirect) { |
| /* |
| * We need to get the dst entry for the |
| * default router instead |
| */ |
| dst_release(*dst); |
| memcpy(&fl_gw6, fl6, sizeof(struct flowi6)); |
| memset(&fl_gw6.daddr, 0, sizeof(struct in6_addr)); |
| *dst = ip6_route_output(net, sk, &fl_gw6); |
| err = (*dst)->error; |
| if (err) |
| goto out_err_release; |
| } |
| } |
| #endif |
| if (ipv6_addr_v4mapped(&fl6->saddr) && |
| !(ipv6_addr_v4mapped(&fl6->daddr) || ipv6_addr_any(&fl6->daddr))) { |
| err = -EAFNOSUPPORT; |
| goto out_err_release; |
| } |
| |
| return 0; |
| |
| out_err_release: |
| dst_release(*dst); |
| *dst = NULL; |
| |
| if (err == -ENETUNREACH) |
| IP6_INC_STATS(net, NULL, IPSTATS_MIB_OUTNOROUTES); |
| return err; |
| } |
| |
| /** |
| * ip6_dst_lookup - perform route lookup on flow |
| * @sk: socket which provides route info |
| * @dst: pointer to dst_entry * for result |
| * @fl6: flow to lookup |
| * |
| * This function performs a route lookup on the given flow. |
| * |
| * It returns zero on success, or a standard errno code on error. |
| */ |
| int ip6_dst_lookup(struct net *net, struct sock *sk, struct dst_entry **dst, |
| struct flowi6 *fl6) |
| { |
| *dst = NULL; |
| return ip6_dst_lookup_tail(net, sk, dst, fl6); |
| } |
| EXPORT_SYMBOL_GPL(ip6_dst_lookup); |
| |
| /** |
| * ip6_dst_lookup_flow - perform route lookup on flow with ipsec |
| * @sk: socket which provides route info |
| * @fl6: flow to lookup |
| * @final_dst: final destination address for ipsec lookup |
| * |
| * This function performs a route lookup on the given flow. |
| * |
| * It returns a valid dst pointer on success, or a pointer encoded |
| * error code. |
| */ |
| struct dst_entry *ip6_dst_lookup_flow(const struct sock *sk, struct flowi6 *fl6, |
| const struct in6_addr *final_dst) |
| { |
| struct dst_entry *dst = NULL; |
| int err; |
| |
| err = ip6_dst_lookup_tail(sock_net(sk), sk, &dst, fl6); |
| if (err) |
| return ERR_PTR(err); |
| if (final_dst) |
| fl6->daddr = *final_dst; |
| |
| return xfrm_lookup_route(sock_net(sk), dst, flowi6_to_flowi(fl6), sk, 0); |
| } |
| EXPORT_SYMBOL_GPL(ip6_dst_lookup_flow); |
| |
| /** |
| * ip6_sk_dst_lookup_flow - perform socket cached route lookup on flow |
| * @sk: socket which provides the dst cache and route info |
| * @fl6: flow to lookup |
| * @final_dst: final destination address for ipsec lookup |
| * @connected: whether @sk is connected or not |
| * |
| * This function performs a route lookup on the given flow with the |
| * possibility of using the cached route in the socket if it is valid. |
| * It will take the socket dst lock when operating on the dst cache. |
| * As a result, this function can only be used in process context. |
| * |
| * In addition, for a connected socket, cache the dst in the socket |
| * if the current cache is not valid. |
| * |
| * It returns a valid dst pointer on success, or a pointer encoded |
| * error code. |
| */ |
| struct dst_entry *ip6_sk_dst_lookup_flow(struct sock *sk, struct flowi6 *fl6, |
| const struct in6_addr *final_dst, |
| bool connected) |
| { |
| struct dst_entry *dst = sk_dst_check(sk, inet6_sk(sk)->dst_cookie); |
| |
| dst = ip6_sk_dst_check(sk, dst, fl6); |
| if (dst) |
| return dst; |
| |
| dst = ip6_dst_lookup_flow(sk, fl6, final_dst); |
| if (connected && !IS_ERR(dst)) |
| ip6_sk_dst_store_flow(sk, dst_clone(dst), fl6); |
| |
| return dst; |
| } |
| EXPORT_SYMBOL_GPL(ip6_sk_dst_lookup_flow); |
| |
| static inline struct ipv6_opt_hdr *ip6_opt_dup(struct ipv6_opt_hdr *src, |
| gfp_t gfp) |
| { |
| return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
| } |
| |
| static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src, |
| gfp_t gfp) |
| { |
| return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL; |
| } |
| |
| static void ip6_append_data_mtu(unsigned int *mtu, |
| int *maxfraglen, |
| unsigned int fragheaderlen, |
| struct sk_buff *skb, |
| struct rt6_info *rt, |
| unsigned int orig_mtu) |
| { |
| if (!(rt->dst.flags & DST_XFRM_TUNNEL)) { |
| if (!skb) { |
| /* first fragment, reserve header_len */ |
| *mtu = orig_mtu - rt->dst.header_len; |
| |
| } else { |
| /* |
| * this fragment is not first, the headers |
| * space is regarded as data space. |
| */ |
| *mtu = orig_mtu; |
| } |
| *maxfraglen = ((*mtu - fragheaderlen) & ~7) |
| + fragheaderlen - sizeof(struct frag_hdr); |
| } |
| } |
| |
| static int ip6_setup_cork(struct sock *sk, struct inet_cork_full *cork, |
| struct inet6_cork *v6_cork, struct ipcm6_cookie *ipc6, |
| struct rt6_info *rt, struct flowi6 *fl6) |
| { |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| unsigned int mtu; |
| struct ipv6_txoptions *opt = ipc6->opt; |
| |
| /* |
| * setup for corking |
| */ |
| if (opt) { |
| if (WARN_ON(v6_cork->opt)) |
| return -EINVAL; |
| |
| v6_cork->opt = kzalloc(sizeof(*opt), sk->sk_allocation); |
| if (unlikely(!v6_cork->opt)) |
| return -ENOBUFS; |
| |
| v6_cork->opt->tot_len = sizeof(*opt); |
| v6_cork->opt->opt_flen = opt->opt_flen; |
| v6_cork->opt->opt_nflen = opt->opt_nflen; |
| |
| v6_cork->opt->dst0opt = ip6_opt_dup(opt->dst0opt, |
| sk->sk_allocation); |
| if (opt->dst0opt && !v6_cork->opt->dst0opt) |
| return -ENOBUFS; |
| |
| v6_cork->opt->dst1opt = ip6_opt_dup(opt->dst1opt, |
| sk->sk_allocation); |
| if (opt->dst1opt && !v6_cork->opt->dst1opt) |
| return -ENOBUFS; |
| |
| v6_cork->opt->hopopt = ip6_opt_dup(opt->hopopt, |
| sk->sk_allocation); |
| if (opt->hopopt && !v6_cork->opt->hopopt) |
| return -ENOBUFS; |
| |
| v6_cork->opt->srcrt = ip6_rthdr_dup(opt->srcrt, |
| sk->sk_allocation); |
| if (opt->srcrt && !v6_cork->opt->srcrt) |
| return -ENOBUFS; |
| |
| /* need source address above miyazawa*/ |
| } |
| dst_hold(&rt->dst); |
| cork->base.dst = &rt->dst; |
| cork->fl.u.ip6 = *fl6; |
| v6_cork->hop_limit = ipc6->hlimit; |
| v6_cork->tclass = ipc6->tclass; |
| if (rt->dst.flags & DST_XFRM_TUNNEL) |
| mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
| READ_ONCE(rt->dst.dev->mtu) : dst_mtu(&rt->dst); |
| else |
| mtu = np->pmtudisc >= IPV6_PMTUDISC_PROBE ? |
| READ_ONCE(rt->dst.dev->mtu) : dst_mtu(xfrm_dst_path(&rt->dst)); |
| if (np->frag_size < mtu) { |
| if (np->frag_size) |
| mtu = np->frag_size; |
| } |
| if (mtu < IPV6_MIN_MTU) |
| return -EINVAL; |
| cork->base.fragsize = mtu; |
| cork->base.gso_size = ipc6->gso_size; |
| cork->base.tx_flags = 0; |
| sock_tx_timestamp(sk, ipc6->sockc.tsflags, &cork->base.tx_flags); |
| |
| if (dst_allfrag(xfrm_dst_path(&rt->dst))) |
| cork->base.flags |= IPCORK_ALLFRAG; |
| cork->base.length = 0; |
| |
| cork->base.transmit_time = ipc6->sockc.transmit_time; |
| |
| return 0; |
| } |
| |
| static int __ip6_append_data(struct sock *sk, |
| struct flowi6 *fl6, |
| struct sk_buff_head *queue, |
| struct inet_cork *cork, |
| struct inet6_cork *v6_cork, |
| struct page_frag *pfrag, |
| int getfrag(void *from, char *to, int offset, |
| int len, int odd, struct sk_buff *skb), |
| void *from, int length, int transhdrlen, |
| unsigned int flags, struct ipcm6_cookie *ipc6) |
| { |
| struct sk_buff *skb, *skb_prev = NULL; |
| unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu, pmtu; |
| struct ubuf_info *uarg = NULL; |
| int exthdrlen = 0; |
| int dst_exthdrlen = 0; |
| int hh_len; |
| int copy; |
| int err; |
| int offset = 0; |
| u32 tskey = 0; |
| struct rt6_info *rt = (struct rt6_info *)cork->dst; |
| struct ipv6_txoptions *opt = v6_cork->opt; |
| int csummode = CHECKSUM_NONE; |
| unsigned int maxnonfragsize, headersize; |
| unsigned int wmem_alloc_delta = 0; |
| bool paged, extra_uref; |
| |
| skb = skb_peek_tail(queue); |
| if (!skb) { |
| exthdrlen = opt ? opt->opt_flen : 0; |
| dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len; |
| } |
| |
| paged = !!cork->gso_size; |
| mtu = cork->gso_size ? IP6_MAX_MTU : cork->fragsize; |
| orig_mtu = mtu; |
| |
| if (cork->tx_flags & SKBTX_ANY_SW_TSTAMP && |
| sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID) |
| tskey = sk->sk_tskey++; |
| |
| hh_len = LL_RESERVED_SPACE(rt->dst.dev); |
| |
| fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len + |
| (opt ? opt->opt_nflen : 0); |
| maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen - |
| sizeof(struct frag_hdr); |
| |
| headersize = sizeof(struct ipv6hdr) + |
| (opt ? opt->opt_flen + opt->opt_nflen : 0) + |
| (dst_allfrag(&rt->dst) ? |
| sizeof(struct frag_hdr) : 0) + |
| rt->rt6i_nfheader_len; |
| |
| /* as per RFC 7112 section 5, the entire IPv6 Header Chain must fit |
| * the first fragment |
| */ |
| if (headersize + transhdrlen > mtu) |
| goto emsgsize; |
| |
| if (cork->length + length > mtu - headersize && ipc6->dontfrag && |
| (sk->sk_protocol == IPPROTO_UDP || |
| sk->sk_protocol == IPPROTO_RAW)) { |
| ipv6_local_rxpmtu(sk, fl6, mtu - headersize + |
| sizeof(struct ipv6hdr)); |
| goto emsgsize; |
| } |
| |
| if (ip6_sk_ignore_df(sk)) |
| maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN; |
| else |
| maxnonfragsize = mtu; |
| |
| if (cork->length + length > maxnonfragsize - headersize) { |
| emsgsize: |
| pmtu = max_t(int, mtu - headersize + sizeof(struct ipv6hdr), 0); |
| ipv6_local_error(sk, EMSGSIZE, fl6, pmtu); |
| return -EMSGSIZE; |
| } |
| |
| /* CHECKSUM_PARTIAL only with no extension headers and when |
| * we are not going to fragment |
| */ |
| if (transhdrlen && sk->sk_protocol == IPPROTO_UDP && |
| headersize == sizeof(struct ipv6hdr) && |
| length <= mtu - headersize && |
| (!(flags & MSG_MORE) || cork->gso_size) && |
| rt->dst.dev->features & (NETIF_F_IPV6_CSUM | NETIF_F_HW_CSUM)) |
| csummode = CHECKSUM_PARTIAL; |
| |
| if (flags & MSG_ZEROCOPY && length && sock_flag(sk, SOCK_ZEROCOPY)) { |
| uarg = sock_zerocopy_realloc(sk, length, skb_zcopy(skb)); |
| if (!uarg) |
| return -ENOBUFS; |
| extra_uref = true; |
| if (rt->dst.dev->features & NETIF_F_SG && |
| csummode == CHECKSUM_PARTIAL) { |
| paged = true; |
| } else { |
| uarg->zerocopy = 0; |
| skb_zcopy_set(skb, uarg, &extra_uref); |
| } |
| } |
| |
| /* |
| * Let's try using as much space as possible. |
| * Use MTU if total length of the message fits into the MTU. |
| * Otherwise, we need to reserve fragment header and |
| * fragment alignment (= 8-15 octects, in total). |
| * |
| * Note that we may need to "move" the data from the tail of |
| * of the buffer to the new fragment when we split |
| * the message. |
| * |
| * FIXME: It may be fragmented into multiple chunks |
| * at once if non-fragmentable extension headers |
| * are too large. |
| * --yoshfuji |
| */ |
| |
| cork->length += length; |
| if (!skb) |
| goto alloc_new_skb; |
| |
| while (length > 0) { |
| /* Check if the remaining data fits into current packet. */ |
| copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len; |
| if (copy < length) |
| copy = maxfraglen - skb->len; |
| |
| if (copy <= 0) { |
| char *data; |
| unsigned int datalen; |
| unsigned int fraglen; |
| unsigned int fraggap; |
| unsigned int alloclen; |
| unsigned int pagedlen; |
| alloc_new_skb: |
| /* There's no room in the current skb */ |
| if (skb) |
| fraggap = skb->len - maxfraglen; |
| else |
| fraggap = 0; |
| /* update mtu and maxfraglen if necessary */ |
| if (!skb || !skb_prev) |
| ip6_append_data_mtu(&mtu, &maxfraglen, |
| fragheaderlen, skb, rt, |
| orig_mtu); |
| |
| skb_prev = skb; |
| |
| /* |
| * If remaining data exceeds the mtu, |
| * we know we need more fragment(s). |
| */ |
| datalen = length + fraggap; |
| |
| if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen) |
| datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len; |
| fraglen = datalen + fragheaderlen; |
| pagedlen = 0; |
| |
| if ((flags & MSG_MORE) && |
| !(rt->dst.dev->features&NETIF_F_SG)) |
| alloclen = mtu; |
| else if (!paged) |
| alloclen = fraglen; |
| else { |
| alloclen = min_t(int, fraglen, MAX_HEADER); |
| pagedlen = fraglen - alloclen; |
| } |
| |
| alloclen += dst_exthdrlen; |
| |
| if (datalen != length + fraggap) { |
| /* |
| * this is not the last fragment, the trailer |
| * space is regarded as data space. |
| */ |
| datalen += rt->dst.trailer_len; |
| } |
| |
| alloclen += rt->dst.trailer_len; |
| fraglen = datalen + fragheaderlen; |
| |
| /* |
| * We just reserve space for fragment header. |
| * Note: this may be overallocation if the message |
| * (without MSG_MORE) fits into the MTU. |
| */ |
| alloclen += sizeof(struct frag_hdr); |
| |
| copy = datalen - transhdrlen - fraggap - pagedlen; |
| if (copy < 0) { |
| err = -EINVAL; |
| goto error; |
| } |
| if (transhdrlen) { |
| skb = sock_alloc_send_skb(sk, |
| alloclen + hh_len, |
| (flags & MSG_DONTWAIT), &err); |
| } else { |
| skb = NULL; |
| if (refcount_read(&sk->sk_wmem_alloc) + wmem_alloc_delta <= |
| 2 * sk->sk_sndbuf) |
| skb = alloc_skb(alloclen + hh_len, |
| sk->sk_allocation); |
| if (unlikely(!skb)) |
| err = -ENOBUFS; |
| } |
| if (!skb) |
| goto error; |
| /* |
| * Fill in the control structures |
| */ |
| skb->protocol = htons(ETH_P_IPV6); |
| skb->ip_summed = csummode; |
| skb->csum = 0; |
| /* reserve for fragmentation and ipsec header */ |
| skb_reserve(skb, hh_len + sizeof(struct frag_hdr) + |
| dst_exthdrlen); |
| |
| /* |
| * Find where to start putting bytes |
| */ |
| data = skb_put(skb, fraglen - pagedlen); |
| skb_set_network_header(skb, exthdrlen); |
| data += fragheaderlen; |
| skb->transport_header = (skb->network_header + |
| fragheaderlen); |
| if (fraggap) { |
| skb->csum = skb_copy_and_csum_bits( |
| skb_prev, maxfraglen, |
| data + transhdrlen, fraggap, 0); |
| skb_prev->csum = csum_sub(skb_prev->csum, |
| skb->csum); |
| data += fraggap; |
| pskb_trim_unique(skb_prev, maxfraglen); |
| } |
| if (copy > 0 && |
| getfrag(from, data + transhdrlen, offset, |
| copy, fraggap, skb) < 0) { |
| err = -EFAULT; |
| kfree_skb(skb); |
| goto error; |
| } |
| |
| offset += copy; |
| length -= copy + transhdrlen; |
| transhdrlen = 0; |
| exthdrlen = 0; |
| dst_exthdrlen = 0; |
| |
| /* Only the initial fragment is time stamped */ |
| skb_shinfo(skb)->tx_flags = cork->tx_flags; |
| cork->tx_flags = 0; |
| skb_shinfo(skb)->tskey = tskey; |
| tskey = 0; |
| skb_zcopy_set(skb, uarg, &extra_uref); |
| |
| if ((flags & MSG_CONFIRM) && !skb_prev) |
| skb_set_dst_pending_confirm(skb, 1); |
| |
| /* |
| * Put the packet on the pending queue |
| */ |
| if (!skb->destructor) { |
| skb->destructor = sock_wfree; |
| skb->sk = sk; |
| wmem_alloc_delta += skb->truesize; |
| } |
| __skb_queue_tail(queue, skb); |
| continue; |
| } |
| |
| if (copy > length) |
| copy = length; |
| |
| if (!(rt->dst.dev->features&NETIF_F_SG) && |
| skb_tailroom(skb) >= copy) { |
| unsigned int off; |
| |
| off = skb->len; |
| if (getfrag(from, skb_put(skb, copy), |
| offset, copy, off, skb) < 0) { |
| __skb_trim(skb, off); |
| err = -EFAULT; |
| goto error; |
| } |
| } else if (!uarg || !uarg->zerocopy) { |
| int i = skb_shinfo(skb)->nr_frags; |
| |
| err = -ENOMEM; |
| if (!sk_page_frag_refill(sk, pfrag)) |
| goto error; |
| |
| if (!skb_can_coalesce(skb, i, pfrag->page, |
| pfrag->offset)) { |
| err = -EMSGSIZE; |
| if (i == MAX_SKB_FRAGS) |
| goto error; |
| |
| __skb_fill_page_desc(skb, i, pfrag->page, |
| pfrag->offset, 0); |
| skb_shinfo(skb)->nr_frags = ++i; |
| get_page(pfrag->page); |
| } |
| copy = min_t(int, copy, pfrag->size - pfrag->offset); |
| if (getfrag(from, |
| page_address(pfrag->page) + pfrag->offset, |
| offset, copy, skb->len, skb) < 0) |
| goto error_efault; |
| |
| pfrag->offset += copy; |
| skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); |
| skb->len += copy; |
| skb->data_len += copy; |
| skb->truesize += copy; |
| wmem_alloc_delta += copy; |
| } else { |
| err = skb_zerocopy_iter_dgram(skb, from, copy); |
| if (err < 0) |
| goto error; |
| } |
| offset += copy; |
| length -= copy; |
| } |
| |
| if (wmem_alloc_delta) |
| refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); |
| return 0; |
| |
| error_efault: |
| err = -EFAULT; |
| error: |
| if (uarg) |
| sock_zerocopy_put_abort(uarg, extra_uref); |
| cork->length -= length; |
| IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS); |
| refcount_add(wmem_alloc_delta, &sk->sk_wmem_alloc); |
| return err; |
| } |
| |
| int ip6_append_data(struct sock *sk, |
| int getfrag(void *from, char *to, int offset, int len, |
| int odd, struct sk_buff *skb), |
| void *from, int length, int transhdrlen, |
| struct ipcm6_cookie *ipc6, struct flowi6 *fl6, |
| struct rt6_info *rt, unsigned int flags) |
| { |
| struct inet_sock *inet = inet_sk(sk); |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| int exthdrlen; |
| int err; |
| |
| if (flags&MSG_PROBE) |
| return 0; |
| if (skb_queue_empty(&sk->sk_write_queue)) { |
| /* |
| * setup for corking |
| */ |
| err = ip6_setup_cork(sk, &inet->cork, &np->cork, |
| ipc6, rt, fl6); |
| if (err) |
| return err; |
| |
| exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); |
| length += exthdrlen; |
| transhdrlen += exthdrlen; |
| } else { |
| fl6 = &inet->cork.fl.u.ip6; |
| transhdrlen = 0; |
| } |
| |
| return __ip6_append_data(sk, fl6, &sk->sk_write_queue, &inet->cork.base, |
| &np->cork, sk_page_frag(sk), getfrag, |
| from, length, transhdrlen, flags, ipc6); |
| } |
| EXPORT_SYMBOL_GPL(ip6_append_data); |
| |
| static void ip6_cork_release(struct inet_cork_full *cork, |
| struct inet6_cork *v6_cork) |
| { |
| if (v6_cork->opt) { |
| kfree(v6_cork->opt->dst0opt); |
| kfree(v6_cork->opt->dst1opt); |
| kfree(v6_cork->opt->hopopt); |
| kfree(v6_cork->opt->srcrt); |
| kfree(v6_cork->opt); |
| v6_cork->opt = NULL; |
| } |
| |
| if (cork->base.dst) { |
| dst_release(cork->base.dst); |
| cork->base.dst = NULL; |
| cork->base.flags &= ~IPCORK_ALLFRAG; |
| } |
| memset(&cork->fl, 0, sizeof(cork->fl)); |
| } |
| |
| struct sk_buff *__ip6_make_skb(struct sock *sk, |
| struct sk_buff_head *queue, |
| struct inet_cork_full *cork, |
| struct inet6_cork *v6_cork) |
| { |
| struct sk_buff *skb, *tmp_skb; |
| struct sk_buff **tail_skb; |
| struct in6_addr final_dst_buf, *final_dst = &final_dst_buf; |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| struct net *net = sock_net(sk); |
| struct ipv6hdr *hdr; |
| struct ipv6_txoptions *opt = v6_cork->opt; |
| struct rt6_info *rt = (struct rt6_info *)cork->base.dst; |
| struct flowi6 *fl6 = &cork->fl.u.ip6; |
| unsigned char proto = fl6->flowi6_proto; |
| |
| skb = __skb_dequeue(queue); |
| if (!skb) |
| goto out; |
| tail_skb = &(skb_shinfo(skb)->frag_list); |
| |
| /* move skb->data to ip header from ext header */ |
| if (skb->data < skb_network_header(skb)) |
| __skb_pull(skb, skb_network_offset(skb)); |
| while ((tmp_skb = __skb_dequeue(queue)) != NULL) { |
| __skb_pull(tmp_skb, skb_network_header_len(skb)); |
| *tail_skb = tmp_skb; |
| tail_skb = &(tmp_skb->next); |
| skb->len += tmp_skb->len; |
| skb->data_len += tmp_skb->len; |
| skb->truesize += tmp_skb->truesize; |
| tmp_skb->destructor = NULL; |
| tmp_skb->sk = NULL; |
| } |
| |
| /* Allow local fragmentation. */ |
| skb->ignore_df = ip6_sk_ignore_df(sk); |
| |
| *final_dst = fl6->daddr; |
| __skb_pull(skb, skb_network_header_len(skb)); |
| if (opt && opt->opt_flen) |
| ipv6_push_frag_opts(skb, opt, &proto); |
| if (opt && opt->opt_nflen) |
| ipv6_push_nfrag_opts(skb, opt, &proto, &final_dst, &fl6->saddr); |
| |
| skb_push(skb, sizeof(struct ipv6hdr)); |
| skb_reset_network_header(skb); |
| hdr = ipv6_hdr(skb); |
| |
| ip6_flow_hdr(hdr, v6_cork->tclass, |
| ip6_make_flowlabel(net, skb, fl6->flowlabel, |
| ip6_autoflowlabel(net, np), fl6)); |
| hdr->hop_limit = v6_cork->hop_limit; |
| hdr->nexthdr = proto; |
| hdr->saddr = fl6->saddr; |
| hdr->daddr = *final_dst; |
| |
| skb->priority = sk->sk_priority; |
| skb->mark = sk->sk_mark; |
| |
| skb->tstamp = cork->base.transmit_time; |
| |
| skb_dst_set(skb, dst_clone(&rt->dst)); |
| IP6_UPD_PO_STATS(net, rt->rt6i_idev, IPSTATS_MIB_OUT, skb->len); |
| if (proto == IPPROTO_ICMPV6) { |
| struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); |
| |
| ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); |
| ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); |
| } |
| |
| ip6_cork_release(cork, v6_cork); |
| out: |
| return skb; |
| } |
| |
| int ip6_send_skb(struct sk_buff *skb) |
| { |
| struct net *net = sock_net(skb->sk); |
| struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); |
| int err; |
| |
| err = ip6_local_out(net, skb->sk, skb); |
| if (err) { |
| if (err > 0) |
| err = net_xmit_errno(err); |
| if (err) |
| IP6_INC_STATS(net, rt->rt6i_idev, |
| IPSTATS_MIB_OUTDISCARDS); |
| } |
| |
| return err; |
| } |
| |
| int ip6_push_pending_frames(struct sock *sk) |
| { |
| struct sk_buff *skb; |
| |
| skb = ip6_finish_skb(sk); |
| if (!skb) |
| return 0; |
| |
| return ip6_send_skb(skb); |
| } |
| EXPORT_SYMBOL_GPL(ip6_push_pending_frames); |
| |
| static void __ip6_flush_pending_frames(struct sock *sk, |
| struct sk_buff_head *queue, |
| struct inet_cork_full *cork, |
| struct inet6_cork *v6_cork) |
| { |
| struct sk_buff *skb; |
| |
| while ((skb = __skb_dequeue_tail(queue)) != NULL) { |
| if (skb_dst(skb)) |
| IP6_INC_STATS(sock_net(sk), ip6_dst_idev(skb_dst(skb)), |
| IPSTATS_MIB_OUTDISCARDS); |
| kfree_skb(skb); |
| } |
| |
| ip6_cork_release(cork, v6_cork); |
| } |
| |
| void ip6_flush_pending_frames(struct sock *sk) |
| { |
| __ip6_flush_pending_frames(sk, &sk->sk_write_queue, |
| &inet_sk(sk)->cork, &inet6_sk(sk)->cork); |
| } |
| EXPORT_SYMBOL_GPL(ip6_flush_pending_frames); |
| |
| struct sk_buff *ip6_make_skb(struct sock *sk, |
| int getfrag(void *from, char *to, int offset, |
| int len, int odd, struct sk_buff *skb), |
| void *from, int length, int transhdrlen, |
| struct ipcm6_cookie *ipc6, struct flowi6 *fl6, |
| struct rt6_info *rt, unsigned int flags, |
| struct inet_cork_full *cork) |
| { |
| struct inet6_cork v6_cork; |
| struct sk_buff_head queue; |
| int exthdrlen = (ipc6->opt ? ipc6->opt->opt_flen : 0); |
| int err; |
| |
| if (flags & MSG_PROBE) |
| return NULL; |
| |
| __skb_queue_head_init(&queue); |
| |
| cork->base.flags = 0; |
| cork->base.addr = 0; |
| cork->base.opt = NULL; |
| cork->base.dst = NULL; |
| v6_cork.opt = NULL; |
| err = ip6_setup_cork(sk, cork, &v6_cork, ipc6, rt, fl6); |
| if (err) { |
| ip6_cork_release(cork, &v6_cork); |
| return ERR_PTR(err); |
| } |
| if (ipc6->dontfrag < 0) |
| ipc6->dontfrag = inet6_sk(sk)->dontfrag; |
| |
| err = __ip6_append_data(sk, fl6, &queue, &cork->base, &v6_cork, |
| ¤t->task_frag, getfrag, from, |
| length + exthdrlen, transhdrlen + exthdrlen, |
| flags, ipc6); |
| if (err) { |
| __ip6_flush_pending_frames(sk, &queue, cork, &v6_cork); |
| return ERR_PTR(err); |
| } |
| |
| return __ip6_make_skb(sk, &queue, cork, &v6_cork); |
| } |