struct sk_buff *ndisc_build_skb(struct net_device *dev,
const struct in6_addr *daddr,
const struct in6_addr *saddr,
struct icmp6hdr *icmp6h,
const struct in6_addr *target,
int llinfo)
{
struct net *net = dev_net(dev);
struct sock *sk = net->ipv6.ndisc_sk;
struct sk_buff *skb;
struct icmp6hdr *hdr;
int len;
int err;
u8 *opt;
if (!dev->addr_len)
llinfo = 0;
len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
if (llinfo)
len += ndisc_opt_addr_space(dev);
skb = sock_alloc_send_skb(sk,
(MAX_HEADER + sizeof(struct ipv6hdr) +
len + LL_ALLOCATED_SPACE(dev)),
1, &err);
if (!skb) {
ND_PRINTK0(KERN_ERR
"ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n",
__func__, err);
return NULL;
}
skb_reserve(skb, LL_RESERVED_SPACE(dev));
ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
skb->transport_header = skb->tail;
skb_put(skb, len);
hdr = (struct icmp6hdr *)skb_transport_header(skb);
memcpy(hdr, icmp6h, sizeof(*hdr));
opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
if (target) {
ipv6_addr_copy((struct in6_addr *)opt, target);
opt += sizeof(*target);
}
if (llinfo)
ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
dev->addr_len, dev->type);
hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
IPPROTO_ICMPV6,
csum_partial(hdr,
len, 0));
return skb;
}
int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *))
{
struct sk_buff *frag;
struct rt6_info *rt = (struct rt6_info*)skb_dst(skb);
struct ipv6_pinfo *np = skb->sk ? inet6_sk(skb->sk) : NULL;
struct ipv6hdr *tmp_hdr;
struct frag_hdr *fh;
unsigned int mtu, hlen, left, len;
__be32 frag_id = 0;
int ptr, offset = 0, err=0;
u8 *prevhdr, nexthdr = 0;
struct net *net = dev_net(skb_dst(skb)->dev);
hlen = ip6_find_1stfragopt(skb, &prevhdr);
nexthdr = *prevhdr;
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 (!skb->local_df && skb->len > mtu) {
skb->dev = skb_dst(skb)->dev;
icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_FRAGFAILS);
kfree_skb(skb);
return -EMSGSIZE;
}
if (np && np->frag_size < mtu) {
if (np->frag_size)
mtu = np->frag_size;
}
mtu -= hlen + sizeof(struct frag_hdr);
if (skb_has_frag_list(skb)) {
int first_len = skb_pagelen(skb);
struct sk_buff *frag2;
if (first_len - hlen > mtu ||
((first_len - hlen) & 7) ||
skb_cloned(skb))
goto slow_path;
skb_walk_frags(skb, frag) {
/* Correct geometry. */
if (frag->len > mtu ||
((frag->len & 7) && frag->next) ||
skb_headroom(frag) < hlen)
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;
frag = skb_shinfo(skb)->frag_list;
skb_frag_list_init(skb);
/* BUILD HEADER */
*prevhdr = NEXTHDR_FRAGMENT;
tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC);
if (!tmp_hdr) {
IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_FRAGFAILS);
return -ENOMEM;
}
__skb_pull(skb, hlen);
fh = (struct frag_hdr*)__skb_push(skb, sizeof(struct frag_hdr));
__skb_push(skb, hlen);
skb_reset_network_header(skb);
memcpy(skb_network_header(skb), tmp_hdr, hlen);
ipv6_select_ident(fh, &rt->rt6i_dst.addr);
fh->nexthdr = nexthdr;
fh->reserved = 0;
fh->frag_off = htons(IP6_MF);
frag_id = fh->identification;
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));
dst_hold(&rt->dst);
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 = (struct frag_hdr*)__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 != NULL)
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(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->next = NULL;
}
kfree(tmp_hdr);
if (err == 0) {
IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
IPSTATS_MIB_FRAGOKS);
dst_release(&rt->dst);
return 0;
}
while (frag) {
skb = frag->next;
kfree_skb(frag);
frag = skb;
}
IP6_INC_STATS(net, ip6_dst_idev(&rt->dst),
IPSTATS_MIB_FRAGFAILS);
dst_release(&rt->dst);
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.
*/
*prevhdr = NEXTHDR_FRAGMENT;
/*
* Keep copying data until we run out.
*/
while(left > 0) {
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.
*/
if ((frag = alloc_skb(len+hlen+sizeof(struct frag_hdr)+LL_ALLOCATED_SPACE(rt->dst.dev), GFP_ATOMIC)) == NULL) {
NETDEBUG(KERN_INFO "IPv6: frag: no memory for new fragment!\n");
IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_FRAGFAILS);
err = -ENOMEM;
goto fail;
}
/*
* Set up data on packet
*/
ip6_copy_metadata(frag, skb);
skb_reserve(frag, LL_RESERVED_SPACE(rt->dst.dev));
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);
/*
* Build fragment header.
*/
fh->nexthdr = nexthdr;
fh->reserved = 0;
if (!frag_id) {
ipv6_select_ident(fh, &rt->rt6i_dst.addr);
frag_id = fh->identification;
} else
fh->identification = frag_id;
/*
* Copy a block of the IP datagram.
*/
if (skb_copy_bits(skb, ptr, skb_transport_header(frag), len))
BUG();
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(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);
kfree_skb(skb);
return err;
fail:
IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)),
IPSTATS_MIB_FRAGFAILS);
kfree_skb(skb);
return err;
}
/*
* Create an arp packet. If (dest_hw == NULL), we create a broadcast
* message.
*/
struct sk_buff *arp_create(int type, int ptype, __be32 dest_ip,
struct net_device *dev, __be32 src_ip,
const unsigned char *dest_hw,
const unsigned char *src_hw,
const unsigned char *target_hw)
{
struct sk_buff *skb;
struct arphdr *arp;
unsigned char *arp_ptr;
/*
* Allocate a buffer
*/
skb = alloc_skb(arp_hdr_len(dev) + LL_ALLOCATED_SPACE(dev), GFP_ATOMIC);
if (skb == NULL)
return NULL;
skb_reserve(skb, LL_RESERVED_SPACE(dev));
skb_reset_network_header(skb);
arp = (struct arphdr *) skb_put(skb, arp_hdr_len(dev));
skb->dev = dev;
skb->protocol = htons(ETH_P_ARP);
if (src_hw == NULL)
src_hw = dev->dev_addr;
if (dest_hw == NULL)
dest_hw = dev->broadcast;
/*
* Fill the device header for the ARP frame
*/
if (dev_hard_header(skb, dev, ptype, dest_hw, src_hw, skb->len) < 0)
goto out;
/*
* Fill out the arp protocol part.
*
* The arp hardware type should match the device type, except for FDDI,
* which (according to RFC 1390) should always equal 1 (Ethernet).
*/
/*
* Exceptions everywhere. AX.25 uses the AX.25 PID value not the
* DIX code for the protocol. Make these device structure fields.
*/
switch (dev->type) {
default:
arp->ar_hrd = htons(dev->type);
arp->ar_pro = htons(ETH_P_IP);
break;
#if defined(CONFIG_AX25) || defined(CONFIG_AX25_MODULE)
case ARPHRD_AX25:
arp->ar_hrd = htons(ARPHRD_AX25);
arp->ar_pro = htons(AX25_P_IP);
break;
#if defined(CONFIG_NETROM) || defined(CONFIG_NETROM_MODULE)
case ARPHRD_NETROM:
arp->ar_hrd = htons(ARPHRD_NETROM);
arp->ar_pro = htons(AX25_P_IP);
break;
#endif
#endif
#ifdef CONFIG_FDDI
case ARPHRD_FDDI:
arp->ar_hrd = htons(ARPHRD_ETHER);
arp->ar_pro = htons(ETH_P_IP);
break;
#endif
#ifdef CONFIG_TR
case ARPHRD_IEEE802_TR:
arp->ar_hrd = htons(ARPHRD_IEEE802);
arp->ar_pro = htons(ETH_P_IP);
break;
#endif
}
arp->ar_hln = dev->addr_len;
arp->ar_pln = 4;
arp->ar_op = htons(type);
arp_ptr=(unsigned char *)(arp+1);
memcpy(arp_ptr, src_hw, dev->addr_len);
arp_ptr+=dev->addr_len;
memcpy(arp_ptr, &src_ip,4);
arp_ptr+=4;
if (target_hw != NULL)
memcpy(arp_ptr, target_hw, dev->addr_len);
else
memset(arp_ptr, 0, dev->addr_len);
arp_ptr+=dev->addr_len;
memcpy(arp_ptr, &dest_ip, 4);
return skb;
out:
kfree_skb(skb);
return NULL;
}
static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
struct rtable *rt,
unsigned int flags)
{
struct inet_sock *inet = inet_sk(sk);
struct net *net = sock_net(sk);
struct iphdr *iph;
struct sk_buff *skb;
unsigned int iphlen;
int err;
if (length > rt->u.dst.dev->mtu) {
ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport,
rt->u.dst.dev->mtu);
return -EMSGSIZE;
}
if (flags&MSG_PROBE)
goto out;
skb = sock_alloc_send_skb(sk,
length + LL_ALLOCATED_SPACE(rt->u.dst.dev) + 15,
flags & MSG_DONTWAIT, &err);
if (skb == NULL)
goto error;
skb_reserve(skb, LL_RESERVED_SPACE(rt->u.dst.dev));
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
skb_dst_set(skb, dst_clone(&rt->u.dst));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
skb_put(skb, length);
skb->ip_summed = CHECKSUM_NONE;
skb->transport_header = skb->network_header;
err = -EFAULT;
if (memcpy_fromiovecend((void *)iph, from, 0, length))
goto error_free;
iphlen = iph->ihl * 4;
/*
* We don't want to modify the ip header, but we do need to
* be sure that it won't cause problems later along the network
* stack. Specifically we want to make sure that iph->ihl is a
* sane value. If ihl points beyond the length of the buffer passed
* in, reject the frame as invalid
*/
err = -EINVAL;
if (iphlen > length)
goto error_free;
if (iphlen >= sizeof(*iph)) {
if (!iph->saddr)
iph->saddr = rt->rt_src;
iph->check = 0;
iph->tot_len = htons(length);
if (!iph->id)
ip_select_ident(iph, &rt->u.dst, NULL);
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
}
if (iph->protocol == IPPROTO_ICMP)
icmp_out_count(net, ((struct icmphdr *)
skb_transport_header(skb))->type);
err = NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
dst_output);
if (err > 0)
err = net_xmit_errno(err);
if (err)
goto error;
out:
return 0;
error_free:
kfree_skb(skb);
error:
IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
if (err == -ENOBUFS && !inet->recverr)
err = 0;
return err;
}
static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
struct rtable *rt,
unsigned int flags)
{
struct inet_sock *inet = inet_sk(sk);
struct net *net = sock_net(sk);
struct iphdr *iph;
struct sk_buff *skb;
unsigned int iphlen;
int err;
if (length > rt->u.dst.dev->mtu) {
ip_local_error(sk, EMSGSIZE, rt->rt_dst, inet->dport,
rt->u.dst.dev->mtu);
return -EMSGSIZE;
}
if (flags&MSG_PROBE)
goto out;
skb = sock_alloc_send_skb(sk,
length + LL_ALLOCATED_SPACE(rt->u.dst.dev) + 15,
flags & MSG_DONTWAIT, &err);
if (skb == NULL)
goto error;
skb_reserve(skb, LL_RESERVED_SPACE(rt->u.dst.dev));
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
skb_dst_set(skb, dst_clone(&rt->u.dst));
skb_reset_network_header(skb);
iph = ip_hdr(skb);
skb_put(skb, length);
skb->ip_summed = CHECKSUM_NONE;
skb->transport_header = skb->network_header;
err = memcpy_fromiovecend((void *)iph, from, 0, length);
if (err)
goto error_fault;
/* We don't modify invalid header */
iphlen = iph->ihl * 4;
if (iphlen >= sizeof(*iph) && iphlen <= length) {
if (!iph->saddr)
iph->saddr = rt->rt_src;
iph->check = 0;
iph->tot_len = htons(length);
if (!iph->id)
ip_select_ident(iph, &rt->u.dst, NULL);
iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
}
if (iph->protocol == IPPROTO_ICMP)
icmp_out_count(net, ((struct icmphdr *)
skb_transport_header(skb))->type);
err = NF_HOOK(PF_INET, NF_INET_LOCAL_OUT, skb, NULL, rt->u.dst.dev,
dst_output);
if (err > 0)
err = net_xmit_errno(err);
if (err)
goto error;
out:
return 0;
error_fault:
err = -EFAULT;
kfree_skb(skb);
error:
IP_INC_STATS(net, IPSTATS_MIB_OUTDISCARDS);
if (err == -ENOBUFS && !inet->recverr)
err = 0;
return err;
}
/*
* Send a Neighbour Advertisement
*/
static void __ndisc_send(struct net_device *dev,
struct neighbour *neigh,
const struct in6_addr *daddr,
const struct in6_addr *saddr,
struct icmp6hdr *icmp6h, const struct in6_addr *target,
int llinfo)
{
struct flowi fl;
struct dst_entry *dst;
struct net *net = dev_net(dev);
struct sock *sk = net->ipv6.ndisc_sk;
struct sk_buff *skb;
struct icmp6hdr *hdr;
struct inet6_dev *idev;
int len;
int err;
u8 *opt, type;
type = icmp6h->icmp6_type;
icmpv6_flow_init(sk, &fl, type, saddr, daddr, dev->ifindex);
dst = icmp6_dst_alloc(dev, neigh, daddr);
if (!dst)
return;
err = xfrm_lookup(&dst, &fl, NULL, 0);
if (err < 0)
return;
if (!dev->addr_len)
llinfo = 0;
len = sizeof(struct icmp6hdr) + (target ? sizeof(*target) : 0);
if (llinfo)
len += ndisc_opt_addr_space(dev);
skb = sock_alloc_send_skb(sk,
(MAX_HEADER + sizeof(struct ipv6hdr) +
len + LL_ALLOCATED_SPACE(dev)),
1, &err);
if (!skb) {
ND_PRINTK0(KERN_ERR
"ICMPv6 ND: %s() failed to allocate an skb.\n",
__func__);
dst_release(dst);
return;
}
skb_reserve(skb, LL_RESERVED_SPACE(dev));
ip6_nd_hdr(sk, skb, dev, saddr, daddr, IPPROTO_ICMPV6, len);
skb->transport_header = skb->tail;
skb_put(skb, len);
hdr = (struct icmp6hdr *)skb_transport_header(skb);
memcpy(hdr, icmp6h, sizeof(*hdr));
opt = skb_transport_header(skb) + sizeof(struct icmp6hdr);
if (target) {
ipv6_addr_copy((struct in6_addr *)opt, target);
opt += sizeof(*target);
}
if (llinfo)
ndisc_fill_addr_option(opt, llinfo, dev->dev_addr,
dev->addr_len, dev->type);
hdr->icmp6_cksum = csum_ipv6_magic(saddr, daddr, len,
IPPROTO_ICMPV6,
csum_partial((__u8 *) hdr,
len, 0));
skb->dst = dst;
idev = in6_dev_get(dst->dev);
IP6_INC_STATS(idev, IPSTATS_MIB_OUTREQUESTS);
err = NF_HOOK(PF_INET6, NF_INET_LOCAL_OUT, skb, NULL, dst->dev,
dst_output);
if (!err) {
ICMP6MSGOUT_INC_STATS(idev, type);
ICMP6_INC_STATS(idev, ICMP6_MIB_OUTMSGS);
}
if (likely(idev != NULL))
in6_dev_put(idev);
}
