- 根目录:
- net
- ipv6
- exthdrs.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 <linux/slab.h>
#include <linux/export.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;
tmp_addr = ipv6h->saddr;
ipv6h->saddr = hao->addr;
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 = skb_dst(skb);
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(dst->dev), ip6_dst_idev(dst),
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
if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
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);
return -1;
}
/********************************
Routing header.
********************************/
/* called with rcu_read_lock() */
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 && 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_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;
}
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_BH(net, ip6_dst_idev(skb_dst(skb)),
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_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));
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;
}
/**
* 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;
fl6->daddr = *((struct rt0_hdr *)opt->srcrt)->addr;
return orig;
}
EXPORT_SYMBOL_GPL(fl6_update_dst);