linux/net/ipv6/exthdrs.c
David S. Miller 2570a4f542 ipv6: skb_dst() can be NULL in ipv6_hop_jumbo().
This fixes CERT-FI FICORA #341748

Discovered by Olli Jarva and Tuomo Untinen from the CROSS
project at Codenomicon Ltd.

Just like in CVE-2007-4567, we can't rely upon skb_dst() being
non-NULL at this point.  We fixed that in commit
e76b2b2567 ("[IPV6]: Do no rely on
skb->dst before it is assigned.")

However commit 483a47d2fe ("ipv6: added
net argument to IP6_INC_STATS_BH") put a new version of the same bug
into this function.

Complicating analysis further, this bug can only trigger when network
namespaces are enabled in the build.  When namespaces are turned off,
the dev_net() does not evaluate it's argument, so the dereference
would not occur.

So, for a long time, namespaces couldn't be turned on unless SYSFS was
disabled.  Therefore, this code has largely been disabled except by
people turning it on explicitly for namespace development.

With help from Eugene Teo <eugene@redhat.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-13 17:27:37 -08:00

876 lines
20 KiB
C

/*
* Extension Header handling for IPv6
* Linux INET6 implementation
*
* Authors:
* Pedro Roque <roque@di.fc.ul.pt>
* Andi Kleen <ak@muc.de>
* Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
*
* 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:
* yoshfuji : ensure not to overrun while parsing
* tlv options.
* Mitsuru KANDA @USAGI and: Remove ipv6_parse_exthdrs().
* YOSHIFUJI Hideaki @USAGI Register inbound extension header
* handlers as inet6_protocol{}.
*/
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/net.h>
#include <linux/netdevice.h>
#include <linux/in6.h>
#include <linux/icmpv6.h>
#include <net/dst.h>
#include <net/sock.h>
#include <net/snmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <net/transp_v6.h>
#include <net/rawv6.h>
#include <net/ndisc.h>
#include <net/ip6_route.h>
#include <net/addrconf.h>
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
#include <net/xfrm.h>
#endif
#include <asm/uaccess.h>
int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
{
const unsigned char *nh = skb_network_header(skb);
int packet_len = skb->tail - skb->network_header;
struct ipv6_opt_hdr *hdr;
int len;
if (offset + 2 > packet_len)
goto bad;
hdr = (struct ipv6_opt_hdr *)(nh + offset);
len = ((hdr->hdrlen + 1) << 3);
if (offset + len > packet_len)
goto bad;
offset += 2;
len -= 2;
while (len > 0) {
int opttype = nh[offset];
int optlen;
if (opttype == type)
return offset;
switch (opttype) {
case IPV6_TLV_PAD0:
optlen = 1;
break;
default:
optlen = nh[offset + 1] + 2;
if (optlen > len)
goto bad;
break;
}
offset += optlen;
len -= optlen;
}
/* not_found */
bad:
return -1;
}
EXPORT_SYMBOL_GPL(ipv6_find_tlv);
/*
* Parsing tlv encoded headers.
*
* Parsing function "func" returns 1, if parsing succeed
* and 0, if it failed.
* It MUST NOT touch skb->h.
*/
struct tlvtype_proc {
int type;
int (*func)(struct sk_buff *skb, int offset);
};
/*********************
Generic functions
*********************/
/* An unknown option is detected, decide what to do */
static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
{
switch ((skb_network_header(skb)[optoff] & 0xC0) >> 6) {
case 0: /* ignore */
return 1;
case 1: /* drop packet */
break;
case 3: /* Send ICMP if not a multicast address and drop packet */
/* Actually, it is redundant check. icmp_send
will recheck in any case.
*/
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr))
break;
case 2: /* send ICMP PARM PROB regardless and drop packet */
icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
return 0;
}
kfree_skb(skb);
return 0;
}
/* Parse tlv encoded option header (hop-by-hop or destination) */
static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
{
struct tlvtype_proc *curr;
const unsigned char *nh = skb_network_header(skb);
int off = skb_network_header_len(skb);
int len = (skb_transport_header(skb)[1] + 1) << 3;
if (skb_transport_offset(skb) + len > skb_headlen(skb))
goto bad;
off += 2;
len -= 2;
while (len > 0) {
int optlen = nh[off + 1] + 2;
switch (nh[off]) {
case IPV6_TLV_PAD0:
optlen = 1;
break;
case IPV6_TLV_PADN:
break;
default: /* Other TLV code so scan list */
if (optlen > len)
goto bad;
for (curr=procs; curr->type >= 0; curr++) {
if (curr->type == nh[off]) {
/* type specific length/alignment
checks will be performed in the
func(). */
if (curr->func(skb, off) == 0)
return 0;
break;
}
}
if (curr->type < 0) {
if (ip6_tlvopt_unknown(skb, off) == 0)
return 0;
}
break;
}
off += optlen;
len -= optlen;
}
if (len == 0)
return 1;
bad:
kfree_skb(skb);
return 0;
}
/*****************************
Destination options header.
*****************************/
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
static int ipv6_dest_hao(struct sk_buff *skb, int optoff)
{
struct ipv6_destopt_hao *hao;
struct inet6_skb_parm *opt = IP6CB(skb);
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
struct in6_addr tmp_addr;
int ret;
if (opt->dsthao) {
LIMIT_NETDEBUG(KERN_DEBUG "hao duplicated\n");
goto discard;
}
opt->dsthao = opt->dst1;
opt->dst1 = 0;
hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) + optoff);
if (hao->length != 16) {
LIMIT_NETDEBUG(
KERN_DEBUG "hao invalid option length = %d\n", hao->length);
goto discard;
}
if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
LIMIT_NETDEBUG(
KERN_DEBUG "hao is not an unicast addr: %pI6\n", &hao->addr);
goto discard;
}
ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
(xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
if (unlikely(ret < 0))
goto discard;
if (skb_cloned(skb)) {
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto discard;
/* update all variable using below by copied skbuff */
hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
optoff);
ipv6h = ipv6_hdr(skb);
}
if (skb->ip_summed == CHECKSUM_COMPLETE)
skb->ip_summed = CHECKSUM_NONE;
ipv6_addr_copy(&tmp_addr, &ipv6h->saddr);
ipv6_addr_copy(&ipv6h->saddr, &hao->addr);
ipv6_addr_copy(&hao->addr, &tmp_addr);
if (skb->tstamp.tv64 == 0)
__net_timestamp(skb);
return 1;
discard:
kfree_skb(skb);
return 0;
}
#endif
static struct tlvtype_proc tlvprocdestopt_lst[] = {
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
{
.type = IPV6_TLV_HAO,
.func = ipv6_dest_hao,
},
#endif
{-1, NULL}
};
static int ipv6_destopt_rcv(struct sk_buff *skb)
{
struct inet6_skb_parm *opt = IP6CB(skb);
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
__u16 dstbuf;
#endif
struct dst_entry *dst;
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_BH(dev_net(skb_dst(skb)->dev), ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
kfree_skb(skb);
return -1;
}
opt->lastopt = opt->dst1 = skb_network_header_len(skb);
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
dstbuf = opt->dst1;
#endif
dst = dst_clone(skb_dst(skb));
if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
dst_release(dst);
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
opt = IP6CB(skb);
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
opt->nhoff = dstbuf;
#else
opt->nhoff = opt->dst1;
#endif
return 1;
}
IP6_INC_STATS_BH(dev_net(dst->dev),
ip6_dst_idev(dst), IPSTATS_MIB_INHDRERRORS);
dst_release(dst);
return -1;
}
/********************************
Routing header.
********************************/
static int ipv6_rthdr_rcv(struct sk_buff *skb)
{
struct inet6_skb_parm *opt = IP6CB(skb);
struct in6_addr *addr = NULL;
struct in6_addr daddr;
struct inet6_dev *idev;
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) {
if (accept_source_route > idev->cnf.accept_source_route)
accept_source_route = idev->cnf.accept_source_route;
in6_dev_put(idev);
}
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_BH(net, ip6_dst_idev(skb_dst(skb)),
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_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
looped_back:
if (hdr->segments_left == 0) {
switch (hdr->type) {
#if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
case IPV6_SRCRT_TYPE_2:
/* Silently discard type 2 header unless it was
* processed by own
*/
if (!addr) {
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
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 defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
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_BH(net, ip6_dst_idev(skb_dst(skb)),
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_BH(net, ip6_dst_idev(skb_dst(skb)),
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_BH(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 defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)
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_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
if (!ipv6_chk_home_addr(dev_net(skb_dst(skb)->dev), addr)) {
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
break;
#endif
default:
break;
}
if (ipv6_addr_is_multicast(addr)) {
IP6_INC_STATS_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INADDRERRORS);
kfree_skb(skb);
return -1;
}
ipv6_addr_copy(&daddr, addr);
ipv6_addr_copy(addr, &ipv6_hdr(skb)->daddr);
ipv6_addr_copy(&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_BH(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_INHDRERRORS);
icmpv6_send(skb, ICMPV6_TIME_EXCEED, ICMPV6_EXC_HOPLIMIT,
0, skb->dev);
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_BH(net, ip6_dst_idev(skb_dst(skb)), 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 | INET6_PROTO_GSO_EXTHDR,
};
static const struct inet6_protocol destopt_protocol = {
.handler = ipv6_destopt_rcv,
.flags = INET6_PROTO_NOPOLICY | INET6_PROTO_GSO_EXTHDR,
};
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_rthdr:
inet6_del_protocol(&rthdr_protocol, IPPROTO_ROUTING);
out_destopt:
inet6_del_protocol(&destopt_protocol, IPPROTO_DSTOPTS);
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 int ipv6_hop_ra(struct sk_buff *skb, int optoff)
{
const unsigned char *nh = skb_network_header(skb);
if (nh[optoff + 1] == 2) {
IP6CB(skb)->ra = optoff;
return 1;
}
LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_ra: wrong RA length %d\n",
nh[optoff + 1]);
kfree_skb(skb);
return 0;
}
/* Jumbo payload */
static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
{
const unsigned char *nh = skb_network_header(skb);
struct net *net = ipv6_skb_net(skb);
u32 pkt_len;
if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
LIMIT_NETDEBUG(KERN_DEBUG "ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
nh[optoff+1]);
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
IPSTATS_MIB_INHDRERRORS);
goto drop;
}
pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
if (pkt_len <= IPV6_MAXPLEN) {
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
return 0;
}
if (ipv6_hdr(skb)->payload_len) {
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
IPSTATS_MIB_INHDRERRORS);
icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
return 0;
}
if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
IP6_INC_STATS_BH(net, ipv6_skb_idev(skb),
IPSTATS_MIB_INTRUNCATEDPKTS);
goto drop;
}
if (pskb_trim_rcsum(skb, pkt_len + sizeof(struct ipv6hdr)))
goto drop;
return 1;
drop:
kfree_skb(skb);
return 0;
}
static struct tlvtype_proc tlvprochopopt_lst[] = {
{
.type = IPV6_TLV_ROUTERALERT,
.func = ipv6_hop_ra,
},
{
.type = IPV6_TLV_JUMBO,
.func = ipv6_hop_jumbo,
},
{ -1, }
};
int ipv6_parse_hopopts(struct sk_buff *skb)
{
struct inet6_skb_parm *opt = IP6CB(skb);
/*
* 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)))) {
kfree_skb(skb);
return -1;
}
opt->hop = sizeof(struct ipv6hdr);
if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
skb->transport_header += (skb_transport_header(skb)[1] + 1) << 3;
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_rthdr(struct sk_buff *skb, u8 *proto,
struct ipv6_rt_hdr *opt,
struct in6_addr **addr_p)
{
struct rt0_hdr *phdr, *ihdr;
int hops;
ihdr = (struct rt0_hdr *) opt;
phdr = (struct rt0_hdr *) 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));
ipv6_addr_copy(phdr->addr + (hops - 1), *addr_p);
*addr_p = ihdr->addr;
phdr->rt_hdr.nexthdr = *proto;
*proto = NEXTHDR_ROUTING;
}
static void ipv6_push_exthdr(struct sk_buff *skb, u8 *proto, u8 type, struct ipv6_opt_hdr *opt)
{
struct ipv6_opt_hdr *h = (struct ipv6_opt_hdr *)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)
{
if (opt->srcrt) {
ipv6_push_rthdr(skb, proto, opt->srcrt, daddr);
/*
* 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);
}
EXPORT_SYMBOL(ipv6_push_nfrag_opts);
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);
}
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;
}
return opt2;
}
EXPORT_SYMBOL_GPL(ipv6_dup_options);
static int ipv6_renew_option(void *ohdr,
struct ipv6_opt_hdr __user *newopt, int newoptlen,
int inherit,
struct ipv6_opt_hdr **hdr,
char **p)
{
if (inherit) {
if (ohdr) {
memcpy(*p, ohdr, ipv6_optlen((struct ipv6_opt_hdr *)ohdr));
*hdr = (struct ipv6_opt_hdr *)*p;
*p += CMSG_ALIGN(ipv6_optlen(*(struct ipv6_opt_hdr **)hdr));
}
} else {
if (newopt) {
if (copy_from_user(*p, newopt, newoptlen))
return -EFAULT;
*hdr = (struct ipv6_opt_hdr *)*p;
if (ipv6_optlen(*(struct ipv6_opt_hdr **)hdr) > newoptlen)
return -EINVAL;
*p += CMSG_ALIGN(newoptlen);
}
}
return 0;
}
struct ipv6_txoptions *
ipv6_renew_options(struct sock *sk, struct ipv6_txoptions *opt,
int newtype,
struct ipv6_opt_hdr __user *newopt, int newoptlen)
{
int tot_len = 0;
char *p;
struct ipv6_txoptions *opt2;
int err;
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 && newoptlen)
tot_len += CMSG_ALIGN(newoptlen);
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);
opt2->tot_len = tot_len;
p = (char *)(opt2 + 1);
err = ipv6_renew_option(opt ? opt->hopopt : NULL, newopt, newoptlen,
newtype != IPV6_HOPOPTS,
&opt2->hopopt, &p);
if (err)
goto out;
err = ipv6_renew_option(opt ? opt->dst0opt : NULL, newopt, newoptlen,
newtype != IPV6_RTHDRDSTOPTS,
&opt2->dst0opt, &p);
if (err)
goto out;
err = ipv6_renew_option(opt ? opt->srcrt : NULL, newopt, newoptlen,
newtype != IPV6_RTHDR,
(struct ipv6_opt_hdr **)&opt2->srcrt, &p);
if (err)
goto out;
err = ipv6_renew_option(opt ? opt->dst1opt : NULL, newopt, newoptlen,
newtype != IPV6_DSTOPTS,
&opt2->dst1opt, &p);
if (err)
goto out;
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;
out:
sock_kfree_s(sk, opt2, opt2->tot_len);
return ERR_PTR(err);
}
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;
}