static int __ip6_append_data(struct sock *sk,
struct flowi6 *fl6,
struct sk_buff_head *queue,
struct inet_cork *cork,
struct inet6_cork *v6_cork,
struct page_frag *pfrag,
int getfrag(void *from, char *to, int offset,
int len, int odd, struct sk_buff *skb),
void *from, int length, int transhdrlen,
unsigned int flags, int dontfrag)
{
struct sk_buff *skb, *skb_prev = NULL;
unsigned int maxfraglen, fragheaderlen, mtu, orig_mtu;
int exthdrlen = 0;
int dst_exthdrlen = 0;
int hh_len;
int copy;
int err;
int offset = 0;
__u8 tx_flags = 0;
u32 tskey = 0;
struct rt6_info *rt = (struct rt6_info *)cork->dst;
struct ipv6_txoptions *opt = v6_cork->opt;
int csummode = CHECKSUM_NONE;
unsigned int maxnonfragsize, headersize;
skb = skb_peek_tail(queue);
if (!skb) {
exthdrlen = opt ? opt->opt_flen : 0;
dst_exthdrlen = rt->dst.header_len - rt->rt6i_nfheader_len;
}
mtu = cork->fragsize;
orig_mtu = mtu;
hh_len = LL_RESERVED_SPACE(rt->dst.dev);
fragheaderlen = sizeof(struct ipv6hdr) + rt->rt6i_nfheader_len +
(opt ? opt->opt_nflen : 0);
maxfraglen = ((mtu - fragheaderlen) & ~7) + fragheaderlen -
sizeof(struct frag_hdr);
headersize = sizeof(struct ipv6hdr) +
(opt ? opt->opt_flen + opt->opt_nflen : 0) +
(dst_allfrag(&rt->dst) ?
sizeof(struct frag_hdr) : 0) +
rt->rt6i_nfheader_len;
if (cork->length + length > mtu - headersize && dontfrag &&
(sk->sk_protocol == IPPROTO_UDP ||
sk->sk_protocol == IPPROTO_RAW)) {
ipv6_local_rxpmtu(sk, fl6, mtu - headersize +
sizeof(struct ipv6hdr));
goto emsgsize;
}
if (ip6_sk_ignore_df(sk))
maxnonfragsize = sizeof(struct ipv6hdr) + IPV6_MAXPLEN;
else
maxnonfragsize = mtu;
if (cork->length + length > maxnonfragsize - headersize) {
emsgsize:
ipv6_local_error(sk, EMSGSIZE, fl6,
mtu - headersize +
sizeof(struct ipv6hdr));
return -EMSGSIZE;
}
/* CHECKSUM_PARTIAL only with no extension headers and when
* we are not going to fragment
*/
if (transhdrlen && sk->sk_protocol == IPPROTO_UDP &&
headersize == sizeof(struct ipv6hdr) &&
length < mtu - headersize &&
!(flags & MSG_MORE) &&
rt->dst.dev->features & NETIF_F_V6_CSUM)
csummode = CHECKSUM_PARTIAL;
if (sk->sk_type == SOCK_DGRAM || sk->sk_type == SOCK_RAW) {
sock_tx_timestamp(sk, &tx_flags);
if (tx_flags & SKBTX_ANY_SW_TSTAMP &&
sk->sk_tsflags & SOF_TIMESTAMPING_OPT_ID)
tskey = sk->sk_tskey++;
}
/*
* Let's try using as much space as possible.
* Use MTU if total length of the message fits into the MTU.
* Otherwise, we need to reserve fragment header and
* fragment alignment (= 8-15 octects, in total).
*
* Note that we may need to "move" the data from the tail of
* of the buffer to the new fragment when we split
* the message.
*
* FIXME: It may be fragmented into multiple chunks
* at once if non-fragmentable extension headers
* are too large.
* --yoshfuji
*/
cork->length += length;
if (((length > mtu) ||
(skb && skb_is_gso(skb))) &&
(sk->sk_protocol == IPPROTO_UDP) &&
(rt->dst.dev->features & NETIF_F_UFO) &&
(sk->sk_type == SOCK_DGRAM) && !udp_get_no_check6_tx(sk)) {
err = ip6_ufo_append_data(sk, queue, getfrag, from, length,
hh_len, fragheaderlen, exthdrlen,
transhdrlen, mtu, flags, fl6);
if (err)
goto error;
return 0;
}
if (!skb)
goto alloc_new_skb;
while (length > 0) {
/* Check if the remaining data fits into current packet. */
copy = (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - skb->len;
if (copy < length)
copy = maxfraglen - skb->len;
if (copy <= 0) {
char *data;
unsigned int datalen;
unsigned int fraglen;
unsigned int fraggap;
unsigned int alloclen;
alloc_new_skb:
/* There's no room in the current skb */
if (skb)
fraggap = skb->len - maxfraglen;
else
fraggap = 0;
/* update mtu and maxfraglen if necessary */
if (!skb || !skb_prev)
ip6_append_data_mtu(&mtu, &maxfraglen,
fragheaderlen, skb, rt,
orig_mtu);
skb_prev = skb;
/*
* If remaining data exceeds the mtu,
* we know we need more fragment(s).
*/
datalen = length + fraggap;
if (datalen > (cork->length <= mtu && !(cork->flags & IPCORK_ALLFRAG) ? mtu : maxfraglen) - fragheaderlen)
datalen = maxfraglen - fragheaderlen - rt->dst.trailer_len;
if ((flags & MSG_MORE) &&
!(rt->dst.dev->features&NETIF_F_SG))
alloclen = mtu;
else
alloclen = datalen + fragheaderlen;
alloclen += dst_exthdrlen;
if (datalen != length + fraggap) {
/*
* this is not the last fragment, the trailer
* space is regarded as data space.
*/
datalen += rt->dst.trailer_len;
}
alloclen += rt->dst.trailer_len;
fraglen = datalen + fragheaderlen;
/*
* We just reserve space for fragment header.
* Note: this may be overallocation if the message
* (without MSG_MORE) fits into the MTU.
*/
alloclen += sizeof(struct frag_hdr);
if (transhdrlen) {
skb = sock_alloc_send_skb(sk,
alloclen + hh_len,
(flags & MSG_DONTWAIT), &err);
} else {
skb = NULL;
if (atomic_read(&sk->sk_wmem_alloc) <=
2 * sk->sk_sndbuf)
skb = sock_wmalloc(sk,
alloclen + hh_len, 1,
sk->sk_allocation);
if (unlikely(!skb))
err = -ENOBUFS;
}
if (!skb)
goto error;
/*
* Fill in the control structures
*/
skb->protocol = htons(ETH_P_IPV6);
skb->ip_summed = csummode;
skb->csum = 0;
/* reserve for fragmentation and ipsec header */
skb_reserve(skb, hh_len + sizeof(struct frag_hdr) +
dst_exthdrlen);
/* Only the initial fragment is time stamped */
skb_shinfo(skb)->tx_flags = tx_flags;
tx_flags = 0;
skb_shinfo(skb)->tskey = tskey;
tskey = 0;
/*
* Find where to start putting bytes
*/
data = skb_put(skb, fraglen);
skb_set_network_header(skb, exthdrlen);
data += fragheaderlen;
skb->transport_header = (skb->network_header +
fragheaderlen);
if (fraggap) {
skb->csum = skb_copy_and_csum_bits(
skb_prev, maxfraglen,
data + transhdrlen, fraggap, 0);
skb_prev->csum = csum_sub(skb_prev->csum,
skb->csum);
data += fraggap;
pskb_trim_unique(skb_prev, maxfraglen);
}
copy = datalen - transhdrlen - fraggap;
if (copy < 0) {
err = -EINVAL;
kfree_skb(skb);
goto error;
} else if (copy > 0 && getfrag(from, data + transhdrlen, offset, copy, fraggap, skb) < 0) {
err = -EFAULT;
kfree_skb(skb);
goto error;
}
offset += copy;
length -= datalen - fraggap;
transhdrlen = 0;
exthdrlen = 0;
dst_exthdrlen = 0;
/*
* Put the packet on the pending queue
*/
__skb_queue_tail(queue, skb);
continue;
}
if (copy > length)
copy = length;
if (!(rt->dst.dev->features&NETIF_F_SG)) {
unsigned int off;
off = skb->len;
if (getfrag(from, skb_put(skb, copy),
offset, copy, off, skb) < 0) {
__skb_trim(skb, off);
err = -EFAULT;
goto error;
}
} else {
int i = skb_shinfo(skb)->nr_frags;
err = -ENOMEM;
if (!sk_page_frag_refill(sk, pfrag))
goto error;
if (!skb_can_coalesce(skb, i, pfrag->page,
pfrag->offset)) {
err = -EMSGSIZE;
if (i == MAX_SKB_FRAGS)
goto error;
__skb_fill_page_desc(skb, i, pfrag->page,
pfrag->offset, 0);
skb_shinfo(skb)->nr_frags = ++i;
get_page(pfrag->page);
}
copy = min_t(int, copy, pfrag->size - pfrag->offset);
if (getfrag(from,
page_address(pfrag->page) + pfrag->offset,
offset, copy, skb->len, skb) < 0)
goto error_efault;
pfrag->offset += copy;
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
skb->len += copy;
skb->data_len += copy;
skb->truesize += copy;
atomic_add(copy, &sk->sk_wmem_alloc);
}
offset += copy;
length -= copy;
}
return 0;
error_efault:
err = -EFAULT;
error:
cork->length -= length;
IP6_INC_STATS(sock_net(sk), rt->rt6i_idev, IPSTATS_MIB_OUTDISCARDS);
return err;
}
static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags,
struct l2tp_tunnel *tunnel, u8 cmd)
{
void *hdr;
struct nlattr *nest;
struct sock *sk = NULL;
struct inet_sock *inet;
#if IS_ENABLED(CONFIG_IPV6)
struct ipv6_pinfo *np = NULL;
#endif
hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd);
if (!hdr)
return -EMSGSIZE;
if (nla_put_u8(skb, L2TP_ATTR_PROTO_VERSION, tunnel->version) ||
nla_put_u32(skb, L2TP_ATTR_CONN_ID, tunnel->tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_PEER_CONN_ID, tunnel->peer_tunnel_id) ||
nla_put_u32(skb, L2TP_ATTR_DEBUG, tunnel->debug) ||
nla_put_u16(skb, L2TP_ATTR_ENCAP_TYPE, tunnel->encap))
goto nla_put_failure;
nest = nla_nest_start(skb, L2TP_ATTR_STATS);
if (nest == NULL)
goto nla_put_failure;
if (nla_put_u64_64bit(skb, L2TP_ATTR_TX_PACKETS,
atomic_long_read(&tunnel->stats.tx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_BYTES,
atomic_long_read(&tunnel->stats.tx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_TX_ERRORS,
atomic_long_read(&tunnel->stats.tx_errors),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_PACKETS,
atomic_long_read(&tunnel->stats.rx_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_BYTES,
atomic_long_read(&tunnel->stats.rx_bytes),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_SEQ_DISCARDS,
atomic_long_read(&tunnel->stats.rx_seq_discards),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_OOS_PACKETS,
atomic_long_read(&tunnel->stats.rx_oos_packets),
L2TP_ATTR_STATS_PAD) ||
nla_put_u64_64bit(skb, L2TP_ATTR_RX_ERRORS,
atomic_long_read(&tunnel->stats.rx_errors),
L2TP_ATTR_STATS_PAD))
goto nla_put_failure;
nla_nest_end(skb, nest);
sk = tunnel->sock;
if (!sk)
goto out;
#if IS_ENABLED(CONFIG_IPV6)
if (sk->sk_family == AF_INET6)
np = inet6_sk(sk);
#endif
inet = inet_sk(sk);
switch (tunnel->encap) {
case L2TP_ENCAPTYPE_UDP:
switch (sk->sk_family) {
case AF_INET:
if (nla_put_u8(skb, L2TP_ATTR_UDP_CSUM, !sk->sk_no_check_tx))
goto nla_put_failure;
break;
#if IS_ENABLED(CONFIG_IPV6)
case AF_INET6:
if (udp_get_no_check6_tx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_TX))
goto nla_put_failure;
if (udp_get_no_check6_rx(sk) &&
nla_put_flag(skb, L2TP_ATTR_UDP_ZERO_CSUM6_RX))
goto nla_put_failure;
break;
#endif
}
if (nla_put_u16(skb, L2TP_ATTR_UDP_SPORT, ntohs(inet->inet_sport)) ||
nla_put_u16(skb, L2TP_ATTR_UDP_DPORT, ntohs(inet->inet_dport)))
goto nla_put_failure;
/* fall through */
case L2TP_ENCAPTYPE_IP:
#if IS_ENABLED(CONFIG_IPV6)
if (np) {
if (nla_put_in6_addr(skb, L2TP_ATTR_IP6_SADDR,
&np->saddr) ||
nla_put_in6_addr(skb, L2TP_ATTR_IP6_DADDR,
&sk->sk_v6_daddr))
goto nla_put_failure;
} else
#endif
if (nla_put_in_addr(skb, L2TP_ATTR_IP_SADDR,
inet->inet_saddr) ||
nla_put_in_addr(skb, L2TP_ATTR_IP_DADDR,
inet->inet_daddr))
goto nla_put_failure;
break;
}
out:
genlmsg_end(skb, hdr);
return 0;
nla_put_failure:
genlmsg_cancel(skb, hdr);
return -1;
}
