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![Paul Moore](/assets/img/avatar_default.png)
At present the ipv6_renew_options_kern() function ends up calling into access_ok() which is problematic if done from inside an interrupt as access_ok() calls WARN_ON_IN_IRQ() on some (all?) architectures (x86-64 is affected). Example warning/backtrace is shown below: WARNING: CPU: 1 PID: 3144 at lib/usercopy.c:11 _copy_from_user+0x85/0x90 ... Call Trace: <IRQ> ipv6_renew_option+0xb2/0xf0 ipv6_renew_options+0x26a/0x340 ipv6_renew_options_kern+0x2c/0x40 calipso_req_setattr+0x72/0xe0 netlbl_req_setattr+0x126/0x1b0 selinux_netlbl_inet_conn_request+0x80/0x100 selinux_inet_conn_request+0x6d/0xb0 security_inet_conn_request+0x32/0x50 tcp_conn_request+0x35f/0xe00 ? __lock_acquire+0x250/0x16c0 ? selinux_socket_sock_rcv_skb+0x1ae/0x210 ? tcp_rcv_state_process+0x289/0x106b tcp_rcv_state_process+0x289/0x106b ? tcp_v6_do_rcv+0x1a7/0x3c0 tcp_v6_do_rcv+0x1a7/0x3c0 tcp_v6_rcv+0xc82/0xcf0 ip6_input_finish+0x10d/0x690 ip6_input+0x45/0x1e0 ? ip6_rcv_finish+0x1d0/0x1d0 ipv6_rcv+0x32b/0x880 ? ip6_make_skb+0x1e0/0x1e0 __netif_receive_skb_core+0x6f2/0xdf0 ? process_backlog+0x85/0x250 ? process_backlog+0x85/0x250 ? process_backlog+0xec/0x250 process_backlog+0xec/0x250 net_rx_action+0x153/0x480 __do_softirq+0xd9/0x4f7 do_softirq_own_stack+0x2a/0x40 </IRQ> ... While not present in the backtrace, ipv6_renew_option() ends up calling access_ok() via the following chain: access_ok() _copy_from_user() copy_from_user() ipv6_renew_option() The fix presented in this patch is to perform the userspace copy earlier in the call chain such that it is only called when the option data is actually coming from userspace; that place is do_ipv6_setsockopt(). Not only does this solve the problem seen in the backtrace above, it also allows us to simplify the code quite a bit by removing ipv6_renew_options_kern() completely. We also take this opportunity to cleanup ipv6_renew_options()/ipv6_renew_option() a small amount as well. This patch is heavily based on a rough patch by Al Viro. I've taken his original patch, converted a kmemdup() call in do_ipv6_setsockopt() to a memdup_user() call, made better use of the e_inval jump target in the same function, and cleaned up the use ipv6_renew_option() by ipv6_renew_options(). CC: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1172 lines
27 KiB
C
1172 lines
27 KiB
C
/*
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* Extension Header handling for IPv6
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* Linux INET6 implementation
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*
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* Authors:
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* Pedro Roque <roque@di.fc.ul.pt>
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* Andi Kleen <ak@muc.de>
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* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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/* Changes:
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* yoshfuji : ensure not to overrun while parsing
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* tlv options.
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* Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
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* YOSHIFUJI Hideaki @USAGI Register inbound extension header
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* handlers as inet6_protocol{}.
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*/
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#include <linux/errno.h>
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#include <linux/types.h>
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#include <linux/socket.h>
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#include <linux/sockios.h>
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#include <linux/net.h>
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#include <linux/netdevice.h>
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#include <linux/in6.h>
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#include <linux/icmpv6.h>
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#include <linux/slab.h>
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#include <linux/export.h>
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#include <net/dst.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ipv6.h>
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#include <net/protocol.h>
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#include <net/transp_v6.h>
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#include <net/rawv6.h>
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#include <net/ndisc.h>
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#include <net/ip6_route.h>
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#include <net/addrconf.h>
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#include <net/calipso.h>
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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#include <net/xfrm.h>
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#endif
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#include <linux/seg6.h>
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#include <net/seg6.h>
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#ifdef CONFIG_IPV6_SEG6_HMAC
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#include <net/seg6_hmac.h>
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#endif
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#include <linux/uaccess.h>
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/*
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* Parsing tlv encoded headers.
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*
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* Parsing function "func" returns true, if parsing succeed
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* and false, if it failed.
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* It MUST NOT touch skb->h.
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*/
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struct tlvtype_proc {
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int type;
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bool (*func)(struct sk_buff *skb, int offset);
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};
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/*********************
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Generic functions
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*********************/
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/* An unknown option is detected, decide what to do */
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static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
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bool disallow_unknowns)
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{
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if (disallow_unknowns) {
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/* If unknown TLVs are disallowed by configuration
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* then always silently drop packet. Note this also
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* means no ICMP parameter problem is sent which
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* could be a good property to mitigate a reflection DOS
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* attack.
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*/
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goto drop;
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}
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switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
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case 0: /* ignore */
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return true;
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case 1: /* drop packet */
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break;
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case 3: /* Send ICMP if not a multicast address and drop packet */
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/* Actually, it is redundant check. icmp_send
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will recheck in any case.
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*/
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if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
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break;
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/* fall through */
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case 2: /* send ICMP PARM PROB regardless and drop packet */
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icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
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return false;
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}
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drop:
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kfree_skb(skb);
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return false;
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}
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/* Parse tlv encoded option header (hop-by-hop or destination) */
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static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
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struct sk_buff *skb,
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int max_count)
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{
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int len = (skb_transport_header(skb)[1] + 1) << 3;
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const unsigned char *nh = skb_network_header(skb);
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int off = skb_network_header_len(skb);
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const struct tlvtype_proc *curr;
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bool disallow_unknowns = false;
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int tlv_count = 0;
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int padlen = 0;
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if (unlikely(max_count < 0)) {
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disallow_unknowns = true;
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max_count = -max_count;
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}
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if (skb_transport_offset(skb) + len > skb_headlen(skb))
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goto bad;
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off += 2;
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len -= 2;
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while (len > 0) {
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int optlen = nh[off + 1] + 2;
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int i;
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switch (nh[off]) {
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case IPV6_TLV_PAD1:
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optlen = 1;
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padlen++;
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if (padlen > 7)
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goto bad;
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break;
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case IPV6_TLV_PADN:
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/* RFC 2460 states that the purpose of PadN is
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* to align the containing header to multiples
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* of 8. 7 is therefore the highest valid value.
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* See also RFC 4942, Section 2.1.9.5.
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*/
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padlen += optlen;
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if (padlen > 7)
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goto bad;
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/* RFC 4942 recommends receiving hosts to
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* actively check PadN payload to contain
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* only zeroes.
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*/
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for (i = 2; i < optlen; i++) {
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if (nh[off + i] != 0)
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goto bad;
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}
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break;
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default: /* Other TLV code so scan list */
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if (optlen > len)
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goto bad;
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tlv_count++;
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if (tlv_count > max_count)
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goto bad;
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for (curr = procs; curr->type >= 0; curr++) {
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if (curr->type == nh[off]) {
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/* type specific length/alignment
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checks will be performed in the
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func(). */
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if (curr->func(skb, off) == false)
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return false;
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break;
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}
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}
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if (curr->type < 0 &&
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!ip6_tlvopt_unknown(skb, off, disallow_unknowns))
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return false;
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padlen = 0;
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break;
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}
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off += optlen;
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len -= optlen;
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}
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if (len == 0)
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return true;
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bad:
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kfree_skb(skb);
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return false;
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}
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/*****************************
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Destination options header.
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*****************************/
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
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{
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struct ipv6_destopt_hao *hao;
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struct inet6_skb_parm *opt = IP6CB(skb);
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struct ipv6hdr *ipv6h = ipv6_hdr(skb);
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int ret;
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if (opt->dsthao) {
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net_dbg_ratelimited("hao duplicated\n");
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goto discard;
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}
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opt->dsthao = opt->dst1;
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opt->dst1 = 0;
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hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
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if (hao->length != 16) {
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net_dbg_ratelimited("hao invalid option length = %d\n",
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hao->length);
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goto discard;
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}
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if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
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net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
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&hao->addr);
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goto discard;
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}
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ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
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(xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
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if (unlikely(ret < 0))
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goto discard;
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if (skb_cloned(skb)) {
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if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
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goto discard;
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/* update all variable using below by copied skbuff */
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hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
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optoff);
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ipv6h = ipv6_hdr(skb);
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}
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if (skb->ip_summed == CHECKSUM_COMPLETE)
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skb->ip_summed = CHECKSUM_NONE;
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swap(ipv6h->saddr, hao->addr);
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if (skb->tstamp == 0)
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__net_timestamp(skb);
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return true;
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discard:
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kfree_skb(skb);
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return false;
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}
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#endif
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static const struct tlvtype_proc tlvprocdestopt_lst[] = {
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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{
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.type = IPV6_TLV_HAO,
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.func = ipv6_dest_hao,
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},
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#endif
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{-1, NULL}
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};
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static int ipv6_destopt_rcv(struct sk_buff *skb)
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{
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struct inet6_dev *idev = __in6_dev_get(skb->dev);
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struct inet6_skb_parm *opt = IP6CB(skb);
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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__u16 dstbuf;
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#endif
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struct dst_entry *dst = skb_dst(skb);
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struct net *net = dev_net(skb->dev);
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int extlen;
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if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
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!pskb_may_pull(skb, (skb_transport_offset(skb) +
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((skb_transport_header(skb)[1] + 1) << 3)))) {
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__IP6_INC_STATS(dev_net(dst->dev), idev,
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IPSTATS_MIB_INHDRERRORS);
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fail_and_free:
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kfree_skb(skb);
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return -1;
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}
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extlen = (skb_transport_header(skb)[1] + 1) << 3;
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if (extlen > net->ipv6.sysctl.max_dst_opts_len)
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goto fail_and_free;
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opt->lastopt = opt->dst1 = skb_network_header_len(skb);
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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dstbuf = opt->dst1;
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#endif
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if (ip6_parse_tlv(tlvprocdestopt_lst, skb,
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init_net.ipv6.sysctl.max_dst_opts_cnt)) {
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skb->transport_header += extlen;
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opt = IP6CB(skb);
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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opt->nhoff = dstbuf;
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#else
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opt->nhoff = opt->dst1;
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#endif
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return 1;
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}
|
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|
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__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
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return -1;
|
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}
|
|
|
|
static void seg6_update_csum(struct sk_buff *skb)
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|
{
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|
struct ipv6_sr_hdr *hdr;
|
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struct in6_addr *addr;
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__be32 from, to;
|
|
|
|
/* srh is at transport offset and seg_left is already decremented
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* but daddr is not yet updated with next segment
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|
*/
|
|
|
|
hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
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addr = hdr->segments + hdr->segments_left;
|
|
|
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hdr->segments_left++;
|
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from = *(__be32 *)hdr;
|
|
|
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hdr->segments_left--;
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to = *(__be32 *)hdr;
|
|
|
|
/* update skb csum with diff resulting from seg_left decrement */
|
|
|
|
update_csum_diff4(skb, from, to);
|
|
|
|
/* compute csum diff between current and next segment and update */
|
|
|
|
update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr),
|
|
(__be32 *)addr);
|
|
}
|
|
|
|
static int ipv6_srh_rcv(struct sk_buff *skb)
|
|
{
|
|
struct inet6_skb_parm *opt = IP6CB(skb);
|
|
struct net *net = dev_net(skb->dev);
|
|
struct ipv6_sr_hdr *hdr;
|
|
struct inet6_dev *idev;
|
|
struct in6_addr *addr;
|
|
int accept_seg6;
|
|
|
|
hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
|
|
|
|
idev = __in6_dev_get(skb->dev);
|
|
|
|
accept_seg6 = net->ipv6.devconf_all->seg6_enabled;
|
|
if (accept_seg6 > idev->cnf.seg6_enabled)
|
|
accept_seg6 = idev->cnf.seg6_enabled;
|
|
|
|
if (!accept_seg6) {
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
|
|
#ifdef CONFIG_IPV6_SEG6_HMAC
|
|
if (!seg6_hmac_validate_skb(skb)) {
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
#endif
|
|
|
|
looped_back:
|
|
if (hdr->segments_left == 0) {
|
|
if (hdr->nexthdr == NEXTHDR_IPV6) {
|
|
int offset = (hdr->hdrlen + 1) << 3;
|
|
|
|
skb_postpull_rcsum(skb, skb_network_header(skb),
|
|
skb_network_header_len(skb));
|
|
|
|
if (!pskb_pull(skb, offset)) {
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
skb_postpull_rcsum(skb, skb_transport_header(skb),
|
|
offset);
|
|
|
|
skb_reset_network_header(skb);
|
|
skb_reset_transport_header(skb);
|
|
skb->encapsulation = 0;
|
|
|
|
__skb_tunnel_rx(skb, skb->dev, net);
|
|
|
|
netif_rx(skb);
|
|
return -1;
|
|
}
|
|
|
|
opt->srcrt = skb_network_header_len(skb);
|
|
opt->lastopt = opt->srcrt;
|
|
skb->transport_header += (hdr->hdrlen + 1) << 3;
|
|
opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
|
|
|
|
return 1;
|
|
}
|
|
|
|
if (hdr->segments_left >= (hdr->hdrlen >> 1)) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
|
|
((&hdr->segments_left) -
|
|
skb_network_header(skb)));
|
|
return -1;
|
|
}
|
|
|
|
if (skb_cloned(skb)) {
|
|
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
|
|
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
|
|
IPSTATS_MIB_OUTDISCARDS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb);
|
|
|
|
hdr->segments_left--;
|
|
addr = hdr->segments + hdr->segments_left;
|
|
|
|
skb_push(skb, sizeof(struct ipv6hdr));
|
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE)
|
|
seg6_update_csum(skb);
|
|
|
|
ipv6_hdr(skb)->daddr = *addr;
|
|
|
|
skb_dst_drop(skb);
|
|
|
|
ip6_route_input(skb);
|
|
|
|
if (skb_dst(skb)->error) {
|
|
dst_input(skb);
|
|
return -1;
|
|
}
|
|
|
|
if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) {
|
|
if (ipv6_hdr(skb)->hop_limit <= 1) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_send(skb, ICMPV6_TIME_EXCEED,
|
|
ICMPV6_EXC_HOPLIMIT, 0);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
ipv6_hdr(skb)->hop_limit--;
|
|
|
|
skb_pull(skb, sizeof(struct ipv6hdr));
|
|
goto looped_back;
|
|
}
|
|
|
|
dst_input(skb);
|
|
|
|
return -1;
|
|
}
|
|
|
|
/********************************
|
|
Routing header.
|
|
********************************/
|
|
|
|
/* called with rcu_read_lock() */
|
|
static int ipv6_rthdr_rcv(struct sk_buff *skb)
|
|
{
|
|
struct inet6_dev *idev = __in6_dev_get(skb->dev);
|
|
struct inet6_skb_parm *opt = IP6CB(skb);
|
|
struct in6_addr *addr = NULL;
|
|
struct in6_addr daddr;
|
|
int n, i;
|
|
struct ipv6_rt_hdr *hdr;
|
|
struct rt0_hdr *rthdr;
|
|
struct net *net = dev_net(skb->dev);
|
|
int accept_source_route = net->ipv6.devconf_all->accept_source_route;
|
|
|
|
idev = __in6_dev_get(skb->dev);
|
|
if (idev && accept_source_route > idev->cnf.accept_source_route)
|
|
accept_source_route = idev->cnf.accept_source_route;
|
|
|
|
if (!pskb_may_pull(skb, skb_transport_offset(skb) + 8) ||
|
|
!pskb_may_pull(skb, (skb_transport_offset(skb) +
|
|
((skb_transport_header(skb)[1] + 1) << 3)))) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
|
|
hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
|
|
|
|
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr) ||
|
|
skb->pkt_type != PACKET_HOST) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
|
|
/* segment routing */
|
|
if (hdr->type == IPV6_SRCRT_TYPE_4)
|
|
return ipv6_srh_rcv(skb);
|
|
|
|
looped_back:
|
|
if (hdr->segments_left == 0) {
|
|
switch (hdr->type) {
|
|
#if IS_ENABLED(CONFIG_IPV6_MIP6)
|
|
case IPV6_SRCRT_TYPE_2:
|
|
/* Silently discard type 2 header unless it was
|
|
* processed by own
|
|
*/
|
|
if (!addr) {
|
|
__IP6_INC_STATS(net, idev,
|
|
IPSTATS_MIB_INADDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
|
|
opt->lastopt = opt->srcrt = skb_network_header_len(skb);
|
|
skb->transport_header += (hdr->hdrlen + 1) << 3;
|
|
opt->dst0 = opt->dst1;
|
|
opt->dst1 = 0;
|
|
opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb);
|
|
return 1;
|
|
}
|
|
|
|
switch (hdr->type) {
|
|
#if IS_ENABLED(CONFIG_IPV6_MIP6)
|
|
case IPV6_SRCRT_TYPE_2:
|
|
if (accept_source_route < 0)
|
|
goto unknown_rh;
|
|
/* Silently discard invalid RTH type 2 */
|
|
if (hdr->hdrlen != 2 || hdr->segments_left != 1) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
goto unknown_rh;
|
|
}
|
|
|
|
/*
|
|
* This is the routing header forwarding algorithm from
|
|
* RFC 2460, page 16.
|
|
*/
|
|
|
|
n = hdr->hdrlen >> 1;
|
|
|
|
if (hdr->segments_left > n) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
|
|
((&hdr->segments_left) -
|
|
skb_network_header(skb)));
|
|
return -1;
|
|
}
|
|
|
|
/* We are about to mangle packet header. Be careful!
|
|
Do not damage packets queued somewhere.
|
|
*/
|
|
if (skb_cloned(skb)) {
|
|
/* the copy is a forwarded packet */
|
|
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
|
|
__IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
|
|
IPSTATS_MIB_OUTDISCARDS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
|
|
}
|
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE)
|
|
skb->ip_summed = CHECKSUM_NONE;
|
|
|
|
i = n - --hdr->segments_left;
|
|
|
|
rthdr = (struct rt0_hdr *) hdr;
|
|
addr = rthdr->addr;
|
|
addr += i - 1;
|
|
|
|
switch (hdr->type) {
|
|
#if IS_ENABLED(CONFIG_IPV6_MIP6)
|
|
case IPV6_SRCRT_TYPE_2:
|
|
if (xfrm6_input_addr(skb, (xfrm_address_t *)addr,
|
|
(xfrm_address_t *)&ipv6_hdr(skb)->saddr,
|
|
IPPROTO_ROUTING) < 0) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
break;
|
|
#endif
|
|
default:
|
|
break;
|
|
}
|
|
|
|
if (ipv6_addr_is_multicast(addr)) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
|
|
daddr = *addr;
|
|
*addr = ipv6_hdr(skb)->daddr;
|
|
ipv6_hdr(skb)->daddr = daddr;
|
|
|
|
skb_dst_drop(skb);
|
|
ip6_route_input(skb);
|
|
if (skb_dst(skb)->error) {
|
|
skb_push(skb, skb->data - skb_network_header(skb));
|
|
dst_input(skb);
|
|
return -1;
|
|
}
|
|
|
|
if (skb_dst(skb)->dev->flags&IFF_LOOPBACK) {
|
|
if (ipv6_hdr(skb)->hop_limit <= 1) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
|
|
0);
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
ipv6_hdr(skb)->hop_limit--;
|
|
goto looped_back;
|
|
}
|
|
|
|
skb_push(skb, skb->data - skb_network_header(skb));
|
|
dst_input(skb);
|
|
return -1;
|
|
|
|
unknown_rh:
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD,
|
|
(&hdr->type) - skb_network_header(skb));
|
|
return -1;
|
|
}
|
|
|
|
static const struct inet6_protocol rthdr_protocol = {
|
|
.handler = ipv6_rthdr_rcv,
|
|
.flags = INET6_PROTO_NOPOLICY,
|
|
};
|
|
|
|
static const struct inet6_protocol destopt_protocol = {
|
|
.handler = ipv6_destopt_rcv,
|
|
.flags = INET6_PROTO_NOPOLICY,
|
|
};
|
|
|
|
static const struct inet6_protocol nodata_protocol = {
|
|
.handler = dst_discard,
|
|
.flags = INET6_PROTO_NOPOLICY,
|
|
};
|
|
|
|
int __init ipv6_exthdrs_init(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = inet6_add_protocol(&rthdr_protocol, IPPROTO_ROUTING);
|
|
if (ret)
|
|
goto out;
|
|
|
|
ret = inet6_add_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
|
|
if (ret)
|
|
goto out_rthdr;
|
|
|
|
ret = inet6_add_protocol(&nodata_protocol, IPPROTO_NONE);
|
|
if (ret)
|
|
goto out_destopt;
|
|
|
|
out:
|
|
return ret;
|
|
out_destopt:
|
|
inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
|
|
out_rthdr:
|
|
inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
|
|
goto out;
|
|
};
|
|
|
|
void ipv6_exthdrs_exit(void)
|
|
{
|
|
inet6_del_protocol(&nodata_protocol, IPPROTO_NONE);
|
|
inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
|
|
inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
|
|
}
|
|
|
|
/**********************************
|
|
Hop-by-hop options.
|
|
**********************************/
|
|
|
|
/*
|
|
* Note: we cannot rely on skb_dst(skb) before we assign it in ip6_route_input().
|
|
*/
|
|
static inline struct inet6_dev *ipv6_skb_idev(struct sk_buff *skb)
|
|
{
|
|
return skb_dst(skb) ? ip6_dst_idev(skb_dst(skb)) : __in6_dev_get(skb->dev);
|
|
}
|
|
|
|
static inline struct net *ipv6_skb_net(struct sk_buff *skb)
|
|
{
|
|
return skb_dst(skb) ? dev_net(skb_dst(skb)->dev) : dev_net(skb->dev);
|
|
}
|
|
|
|
/* Router Alert as of RFC 2711 */
|
|
|
|
static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
|
|
{
|
|
const unsigned char *nh = skb_network_header(skb);
|
|
|
|
if (nh[optoff + 1] == 2) {
|
|
IP6CB(skb)->flags |= IP6SKB_ROUTERALERT;
|
|
memcpy(&IP6CB(skb)->ra, nh + optoff + 2, sizeof(IP6CB(skb)->ra));
|
|
return true;
|
|
}
|
|
net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
|
|
nh[optoff + 1]);
|
|
kfree_skb(skb);
|
|
return false;
|
|
}
|
|
|
|
/* Jumbo payload */
|
|
|
|
static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
|
|
{
|
|
const unsigned char *nh = skb_network_header(skb);
|
|
struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
|
|
struct net *net = ipv6_skb_net(skb);
|
|
u32 pkt_len;
|
|
|
|
if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
|
|
net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
|
|
nh[optoff+1]);
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
goto drop;
|
|
}
|
|
|
|
pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
|
|
if (pkt_len <= IPV6_MAXPLEN) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
|
|
return false;
|
|
}
|
|
if (ipv6_hdr(skb)->payload_len) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
|
|
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
|
|
return false;
|
|
}
|
|
|
|
if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
|
|
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
|
|
goto drop;
|
|
}
|
|
|
|
if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
|
|
goto drop;
|
|
|
|
IP6CB(skb)->flags |= IP6SKB_JUMBOGRAM;
|
|
return true;
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return false;
|
|
}
|
|
|
|
/* CALIPSO RFC 5570 */
|
|
|
|
static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
|
|
{
|
|
const unsigned char *nh = skb_network_header(skb);
|
|
|
|
if (nh[optoff + 1] < 8)
|
|
goto drop;
|
|
|
|
if (nh[optoff + 6] * 4 + 8 > nh[optoff + 1])
|
|
goto drop;
|
|
|
|
if (!calipso_validate(skb, nh + optoff))
|
|
goto drop;
|
|
|
|
return true;
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return false;
|
|
}
|
|
|
|
static const struct tlvtype_proc tlvprochopopt_lst[] = {
|
|
{
|
|
.type = IPV6_TLV_ROUTERALERT,
|
|
.func = ipv6_hop_ra,
|
|
},
|
|
{
|
|
.type = IPV6_TLV_JUMBO,
|
|
.func = ipv6_hop_jumbo,
|
|
},
|
|
{
|
|
.type = IPV6_TLV_CALIPSO,
|
|
.func = ipv6_hop_calipso,
|
|
},
|
|
{ -1, }
|
|
};
|
|
|
|
int ipv6_parse_hopopts(struct sk_buff *skb)
|
|
{
|
|
struct inet6_skb_parm *opt = IP6CB(skb);
|
|
struct net *net = dev_net(skb->dev);
|
|
int extlen;
|
|
|
|
/*
|
|
* skb_network_header(skb) is equal to skb->data, and
|
|
* skb_network_header_len(skb) is always equal to
|
|
* sizeof(struct ipv6hdr) by definition of
|
|
* hop-by-hop options.
|
|
*/
|
|
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr) + 8) ||
|
|
!pskb_may_pull(skb, (sizeof(struct ipv6hdr) +
|
|
((skb_transport_header(skb)[1] + 1) << 3)))) {
|
|
fail_and_free:
|
|
kfree_skb(skb);
|
|
return -1;
|
|
}
|
|
|
|
extlen = (skb_transport_header(skb)[1] + 1) << 3;
|
|
if (extlen > net->ipv6.sysctl.max_hbh_opts_len)
|
|
goto fail_and_free;
|
|
|
|
opt->flags |= IP6SKB_HOPBYHOP;
|
|
if (ip6_parse_tlv(tlvprochopopt_lst, skb,
|
|
init_net.ipv6.sysctl.max_hbh_opts_cnt)) {
|
|
skb->transport_header += extlen;
|
|
opt = IP6CB(skb);
|
|
opt->nhoff = sizeof(struct ipv6hdr);
|
|
return 1;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Creating outbound headers.
|
|
*
|
|
* "build" functions work when skb is filled from head to tail (datagram)
|
|
* "push" functions work when headers are added from tail to head (tcp)
|
|
*
|
|
* In both cases we assume, that caller reserved enough room
|
|
* for headers.
|
|
*/
|
|
|
|
static void ipv6_push_rthdr0(struct sk_buff *skb, u8 *proto,
|
|
struct ipv6_rt_hdr *opt,
|
|
struct in6_addr **addr_p, struct in6_addr *saddr)
|
|
{
|
|
struct rt0_hdr *phdr, *ihdr;
|
|
int hops;
|
|
|
|
ihdr = (struct rt0_hdr *) opt;
|
|
|
|
phdr = skb_push(skb, (ihdr->rt_hdr.hdrlen + 1) << 3);
|
|
memcpy(phdr, ihdr, sizeof(struct rt0_hdr));
|
|
|
|
hops = ihdr->rt_hdr.hdrlen >> 1;
|
|
|
|
if (hops > 1)
|
|
memcpy(phdr->addr, ihdr->addr + 1,
|
|
(hops - 1) * sizeof(struct in6_addr));
|
|
|
|
phdr->addr[hops - 1] = **addr_p;
|
|
*addr_p = ihdr->addr;
|
|
|
|
phdr->rt_hdr.nexthdr = *proto;
|
|
*proto = NEXTHDR_ROUTING;
|
|
}
|
|
|
|
static void ipv6_push_rthdr4(struct sk_buff *skb, u8 *proto,
|
|
struct ipv6_rt_hdr *opt,
|
|
struct in6_addr **addr_p, struct in6_addr *saddr)
|
|
{
|
|
struct ipv6_sr_hdr *sr_phdr, *sr_ihdr;
|
|
int plen, hops;
|
|
|
|
sr_ihdr = (struct ipv6_sr_hdr *)opt;
|
|
plen = (sr_ihdr->hdrlen + 1) << 3;
|
|
|
|
sr_phdr = skb_push(skb, plen);
|
|
memcpy(sr_phdr, sr_ihdr, sizeof(struct ipv6_sr_hdr));
|
|
|
|
hops = sr_ihdr->first_segment + 1;
|
|
memcpy(sr_phdr->segments + 1, sr_ihdr->segments + 1,
|
|
(hops - 1) * sizeof(struct in6_addr));
|
|
|
|
sr_phdr->segments[0] = **addr_p;
|
|
*addr_p = &sr_ihdr->segments[sr_ihdr->segments_left];
|
|
|
|
if (sr_ihdr->hdrlen > hops * 2) {
|
|
int tlvs_offset, tlvs_length;
|
|
|
|
tlvs_offset = (1 + hops * 2) << 3;
|
|
tlvs_length = (sr_ihdr->hdrlen - hops * 2) << 3;
|
|
memcpy((char *)sr_phdr + tlvs_offset,
|
|
(char *)sr_ihdr + tlvs_offset, tlvs_length);
|
|
}
|
|
|
|
#ifdef CONFIG_IPV6_SEG6_HMAC
|
|
if (sr_has_hmac(sr_phdr)) {
|
|
struct net *net = NULL;
|
|
|
|
if (skb->dev)
|
|
net = dev_net(skb->dev);
|
|
else if (skb->sk)
|
|
net = sock_net(skb->sk);
|
|
|
|
WARN_ON(!net);
|
|
|
|
if (net)
|
|
seg6_push_hmac(net, saddr, sr_phdr);
|
|
}
|
|
#endif
|
|
|
|
sr_phdr->nexthdr = *proto;
|
|
*proto = NEXTHDR_ROUTING;
|
|
}
|
|
|
|
static void ipv6_push_rthdr(struct sk_buff *skb, u8 *proto,
|
|
struct ipv6_rt_hdr *opt,
|
|
struct in6_addr **addr_p, struct in6_addr *saddr)
|
|
{
|
|
switch (opt->type) {
|
|
case IPV6_SRCRT_TYPE_0:
|
|
case IPV6_SRCRT_STRICT:
|
|
case IPV6_SRCRT_TYPE_2:
|
|
ipv6_push_rthdr0(skb, proto, opt, addr_p, saddr);
|
|
break;
|
|
case IPV6_SRCRT_TYPE_4:
|
|
ipv6_push_rthdr4(skb, proto, opt, addr_p, saddr);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
|
|
{
|
|
struct ipv6_opt_hdr *h = skb_push(skb, ipv6_optlen(opt));
|
|
|
|
memcpy(h, opt, ipv6_optlen(opt));
|
|
h->nexthdr = *proto;
|
|
*proto = type;
|
|
}
|
|
|
|
void ipv6_push_nfrag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt,
|
|
u8 *proto,
|
|
struct in6_addr **daddr, struct in6_addr *saddr)
|
|
{
|
|
if (opt->srcrt) {
|
|
ipv6_push_rthdr(skb, proto, opt->srcrt, daddr, saddr);
|
|
/*
|
|
* IPV6_RTHDRDSTOPTS is ignored
|
|
* unless IPV6_RTHDR is set (RFC3542).
|
|
*/
|
|
if (opt->dst0opt)
|
|
ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst0opt);
|
|
}
|
|
if (opt->hopopt)
|
|
ipv6_push_exthdr(skb, proto, NEXTHDR_HOP, opt->hopopt);
|
|
}
|
|
|
|
void ipv6_push_frag_opts(struct sk_buff *skb, struct ipv6_txoptions *opt, u8 *proto)
|
|
{
|
|
if (opt->dst1opt)
|
|
ipv6_push_exthdr(skb, proto, NEXTHDR_DEST, opt->dst1opt);
|
|
}
|
|
EXPORT_SYMBOL(ipv6_push_frag_opts);
|
|
|
|
struct ipv6_txoptions *
|
|
ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
|
|
{
|
|
struct ipv6_txoptions *opt2;
|
|
|
|
opt2 = sock_kmalloc(sk, opt->tot_len, GFP_ATOMIC);
|
|
if (opt2) {
|
|
long dif = (char *)opt2 - (char *)opt;
|
|
memcpy(opt2, opt, opt->tot_len);
|
|
if (opt2->hopopt)
|
|
*((char **)&opt2->hopopt) += dif;
|
|
if (opt2->dst0opt)
|
|
*((char **)&opt2->dst0opt) += dif;
|
|
if (opt2->dst1opt)
|
|
*((char **)&opt2->dst1opt) += dif;
|
|
if (opt2->srcrt)
|
|
*((char **)&opt2->srcrt) += dif;
|
|
refcount_set(&opt2->refcnt, 1);
|
|
}
|
|
return opt2;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv6_dup_options);
|
|
|
|
static void ipv6_renew_option(int renewtype,
|
|
struct ipv6_opt_hdr **dest,
|
|
struct ipv6_opt_hdr *old,
|
|
struct ipv6_opt_hdr *new,
|
|
int newtype, char **p)
|
|
{
|
|
struct ipv6_opt_hdr *src;
|
|
|
|
src = (renewtype == newtype ? new : old);
|
|
if (!src)
|
|
return;
|
|
|
|
memcpy(*p, src, ipv6_optlen(src));
|
|
*dest = (struct ipv6_opt_hdr *)*p;
|
|
*p += CMSG_ALIGN(ipv6_optlen(*dest));
|
|
}
|
|
|
|
/**
|
|
* ipv6_renew_options - replace a specific ext hdr with a new one.
|
|
*
|
|
* @sk: sock from which to allocate memory
|
|
* @opt: original options
|
|
* @newtype: option type to replace in @opt
|
|
* @newopt: new option of type @newtype to replace (user-mem)
|
|
* @newoptlen: length of @newopt
|
|
*
|
|
* Returns a new set of options which is a copy of @opt with the
|
|
* option type @newtype replaced with @newopt.
|
|
*
|
|
* @opt may be NULL, in which case a new set of options is returned
|
|
* containing just @newopt.
|
|
*
|
|
* @newopt may be NULL, in which case the specified option type is
|
|
* not copied into the new set of options.
|
|
*
|
|
* The new set of options is allocated from the socket option memory
|
|
* buffer of @sk.
|
|
*/
|
|
struct ipv6_txoptions *
|
|
ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
|
|
int newtype, struct ipv6_opt_hdr *newopt)
|
|
{
|
|
int tot_len = 0;
|
|
char *p;
|
|
struct ipv6_txoptions *opt2;
|
|
|
|
if (opt) {
|
|
if (newtype != IPV6_HOPOPTS && opt->hopopt)
|
|
tot_len += CMSG_ALIGN(ipv6_optlen(opt->hopopt));
|
|
if (newtype != IPV6_RTHDRDSTOPTS && opt->dst0opt)
|
|
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst0opt));
|
|
if (newtype != IPV6_RTHDR && opt->srcrt)
|
|
tot_len += CMSG_ALIGN(ipv6_optlen(opt->srcrt));
|
|
if (newtype != IPV6_DSTOPTS && opt->dst1opt)
|
|
tot_len += CMSG_ALIGN(ipv6_optlen(opt->dst1opt));
|
|
}
|
|
|
|
if (newopt)
|
|
tot_len += CMSG_ALIGN(ipv6_optlen(newopt));
|
|
|
|
if (!tot_len)
|
|
return NULL;
|
|
|
|
tot_len += sizeof(*opt2);
|
|
opt2 = sock_kmalloc(sk, tot_len, GFP_ATOMIC);
|
|
if (!opt2)
|
|
return ERR_PTR(-ENOBUFS);
|
|
|
|
memset(opt2, 0, tot_len);
|
|
refcount_set(&opt2->refcnt, 1);
|
|
opt2->tot_len = tot_len;
|
|
p = (char *)(opt2 + 1);
|
|
|
|
ipv6_renew_option(IPV6_HOPOPTS, &opt2->hopopt,
|
|
(opt ? opt->hopopt : NULL),
|
|
newopt, newtype, &p);
|
|
ipv6_renew_option(IPV6_RTHDRDSTOPTS, &opt2->dst0opt,
|
|
(opt ? opt->dst0opt : NULL),
|
|
newopt, newtype, &p);
|
|
ipv6_renew_option(IPV6_RTHDR,
|
|
(struct ipv6_opt_hdr **)&opt2->srcrt,
|
|
(opt ? (struct ipv6_opt_hdr *)opt->srcrt : NULL),
|
|
newopt, newtype, &p);
|
|
ipv6_renew_option(IPV6_DSTOPTS, &opt2->dst1opt,
|
|
(opt ? opt->dst1opt : NULL),
|
|
newopt, newtype, &p);
|
|
|
|
opt2->opt_nflen = (opt2->hopopt ? ipv6_optlen(opt2->hopopt) : 0) +
|
|
(opt2->dst0opt ? ipv6_optlen(opt2->dst0opt) : 0) +
|
|
(opt2->srcrt ? ipv6_optlen(opt2->srcrt) : 0);
|
|
opt2->opt_flen = (opt2->dst1opt ? ipv6_optlen(opt2->dst1opt) : 0);
|
|
|
|
return opt2;
|
|
}
|
|
|
|
struct ipv6_txoptions *ipv6_fixup_options(struct ipv6_txoptions *opt_space,
|
|
struct ipv6_txoptions *opt)
|
|
{
|
|
/*
|
|
* ignore the dest before srcrt unless srcrt is being included.
|
|
* --yoshfuji
|
|
*/
|
|
if (opt && opt->dst0opt && !opt->srcrt) {
|
|
if (opt_space != opt) {
|
|
memcpy(opt_space, opt, sizeof(*opt_space));
|
|
opt = opt_space;
|
|
}
|
|
opt->opt_nflen -= ipv6_optlen(opt->dst0opt);
|
|
opt->dst0opt = NULL;
|
|
}
|
|
|
|
return opt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(ipv6_fixup_options);
|
|
|
|
/**
|
|
* fl6_update_dst - update flowi destination address with info given
|
|
* by srcrt option, if any.
|
|
*
|
|
* @fl6: flowi6 for which daddr is to be updated
|
|
* @opt: struct ipv6_txoptions in which to look for srcrt opt
|
|
* @orig: copy of original daddr address if modified
|
|
*
|
|
* Returns NULL if no txoptions or no srcrt, otherwise returns orig
|
|
* and initial value of fl6->daddr set in orig
|
|
*/
|
|
struct in6_addr *fl6_update_dst(struct flowi6 *fl6,
|
|
const struct ipv6_txoptions *opt,
|
|
struct in6_addr *orig)
|
|
{
|
|
if (!opt || !opt->srcrt)
|
|
return NULL;
|
|
|
|
*orig = fl6->daddr;
|
|
|
|
switch (opt->srcrt->type) {
|
|
case IPV6_SRCRT_TYPE_0:
|
|
case IPV6_SRCRT_STRICT:
|
|
case IPV6_SRCRT_TYPE_2:
|
|
fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
|
|
break;
|
|
case IPV6_SRCRT_TYPE_4:
|
|
{
|
|
struct ipv6_sr_hdr *srh = (struct ipv6_sr_hdr *)opt->srcrt;
|
|
|
|
fl6->daddr = srh->segments[srh->segments_left];
|
|
break;
|
|
}
|
|
default:
|
|
return NULL;
|
|
}
|
|
|
|
return orig;
|
|
}
|
|
EXPORT_SYMBOL_GPL(fl6_update_dst);
|