/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
* @data: raw buffer pointer to the packet, if NULL use skb->data
* @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
* @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
*
* The function will try to retrieve the struct flow_keys from either the skbuff
* or a raw buffer specified by the rest parameters
*/
bool __skb_flow_dissect(const struct sk_buff *skb, struct flow_keys *flow,
void *data, __be16 proto, int nhoff, int hlen)
{
u8 ip_proto;
if (!data) {
data = skb->data;
proto = skb->protocol;
nhoff = skb_network_offset(skb);
hlen = skb_headlen(skb);
}
memset(flow, 0, sizeof(*flow));
again:
switch (proto) {
case htons(ETH_P_IP): {
const struct iphdr *iph;
struct iphdr _iph;
ip:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph || iph->ihl < 5)
return false;
nhoff += iph->ihl * 4;
ip_proto = iph->protocol;
if (ip_is_fragment(iph))
ip_proto = 0;
/* skip the address processing if skb is NULL. The assumption
* here is that if there is no skb we are not looking for flow
* info but lengths and protocols.
*/
if (!skb)
break;
iph_to_flow_copy_addrs(flow, iph);
break;
}
case htons(ETH_P_IPV6): {
const struct ipv6hdr *iph;
struct ipv6hdr _iph;
__be32 flow_label;
ipv6:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph)
return false;
ip_proto = iph->nexthdr;
nhoff += sizeof(struct ipv6hdr);
/* see comment above in IPv4 section */
if (!skb)
break;
flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr);
flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr);
flow_label = ip6_flowlabel(iph);
if (flow_label) {
/* Awesome, IPv6 packet has a flow label so we can
* use that to represent the ports without any
* further dissection.
*/
flow->n_proto = proto;
flow->ip_proto = ip_proto;
flow->ports = flow_label;
flow->thoff = (u16)nhoff;
return true;
}
break;
}
case htons(ETH_P_8021AD):
case htons(ETH_P_8021Q): {
const struct vlan_hdr *vlan;
struct vlan_hdr _vlan;
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
if (!vlan)
return false;
proto = vlan->h_vlan_encapsulated_proto;
nhoff += sizeof(*vlan);
goto again;
}
case htons(ETH_P_PPP_SES): {
struct {
struct pppoe_hdr hdr;
__be16 proto;
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
return false;
proto = hdr->proto;
nhoff += PPPOE_SES_HLEN;
switch (proto) {
case htons(PPP_IP):
goto ip;
case htons(PPP_IPV6):
goto ipv6;
default:
return false;
}
}
case __constant_htons(ETH_P_MAP): {
struct {
struct rmnet_map_header_s map;
uint8_t proto;
} *map, _map;
unsigned int maplen;
map = skb_header_pointer(skb, nhoff, sizeof(_map), &_map);
if (!map)
return false;
/* Is MAP command? */
if (map->map.cd_bit)
return false;
/* Is aggregated frame? */
maplen = ntohs(map->map.pkt_len);
maplen += map->map.pad_len;
maplen += sizeof(struct rmnet_map_header_s);
if (maplen < skb->len)
return false;
nhoff += sizeof(struct rmnet_map_header_s);
switch (map->proto & RMNET_IP_VER_MASK) {
case RMNET_IPV4:
proto = htons(ETH_P_IP);
goto ip;
case RMNET_IPV6:
proto = htons(ETH_P_IPV6);
goto ipv6;
default:
return false;
}
}
case htons(ETH_P_FCOE):
flow->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
/* fall through */
default:
return false;
}
switch (ip_proto) {
case IPPROTO_GRE: {
struct gre_hdr {
__be16 flags;
__be16 proto;
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
return false;
/*
* Only look inside GRE if version zero and no
* routing
*/
if (!(hdr->flags & (GRE_VERSION|GRE_ROUTING))) {
proto = hdr->proto;
nhoff += 4;
if (hdr->flags & GRE_CSUM)
nhoff += 4;
if (hdr->flags & GRE_KEY)
nhoff += 4;
if (hdr->flags & GRE_SEQ)
nhoff += 4;
if (proto == htons(ETH_P_TEB)) {
const struct ethhdr *eth;
struct ethhdr _eth;
eth = __skb_header_pointer(skb, nhoff,
sizeof(_eth),
data, hlen, &_eth);
if (!eth)
return false;
proto = eth->h_proto;
nhoff += sizeof(*eth);
}
goto again;
}
break;
}
case IPPROTO_IPIP:
proto = htons(ETH_P_IP);
goto ip;
case IPPROTO_IPV6:
proto = htons(ETH_P_IPV6);
goto ipv6;
default:
break;
}
flow->n_proto = proto;
flow->ip_proto = ip_proto;
flow->thoff = (u16) nhoff;
/* unless skb is set we don't need to record port info */
if (skb)
flow->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
data, hlen);
return true;
}
/* The socket must have it's spinlock held when we get
* here.
*
* We have a potential double-lock case here, so even when
* doing backlog processing we use the BH locking scheme.
* This is because we cannot sleep with the original spinlock
* held.
*/
static int dccp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
{
struct ipv6_pinfo *np = inet6_sk(sk);
struct sk_buff *opt_skb = NULL;
/* Imagine: socket is IPv6. IPv4 packet arrives,
goes to IPv4 receive handler and backlogged.
From backlog it always goes here. Kerboom...
Fortunately, dccp_rcv_established and rcv_established
handle them correctly, but it is not case with
dccp_v6_hnd_req and dccp_v6_ctl_send_reset(). --ANK
*/
if (skb->protocol == htons(ETH_P_IP))
return dccp_v4_do_rcv(sk, skb);
if (sk_filter(sk, skb))
goto discard;
/*
* socket locking is here for SMP purposes as backlog rcv is currently
* called with bh processing disabled.
*/
/* Do Stevens' IPV6_PKTOPTIONS.
Yes, guys, it is the only place in our code, where we
may make it not affecting IPv4.
The rest of code is protocol independent,
and I do not like idea to uglify IPv4.
Actually, all the idea behind IPV6_PKTOPTIONS
looks not very well thought. For now we latch
options, received in the last packet, enqueued
by tcp. Feel free to propose better solution.
--ANK (980728)
*/
if (np->rxopt.all)
opt_skb = skb_clone(skb, GFP_ATOMIC);
if (sk->sk_state == DCCP_OPEN) { /* Fast path */
if (dccp_rcv_established(sk, skb, dccp_hdr(skb), skb->len))
goto reset;
if (opt_skb)
goto ipv6_pktoptions;
return 0;
}
/*
* Step 3: Process LISTEN state
* If S.state == LISTEN,
* If P.type == Request or P contains a valid Init Cookie option,
* (* Must scan the packet's options to check for Init
* Cookies. Only Init Cookies are processed here,
* however; other options are processed in Step 8. This
* scan need only be performed if the endpoint uses Init
* Cookies *)
* (* Generate a new socket and switch to that socket *)
* Set S := new socket for this port pair
* S.state = RESPOND
* Choose S.ISS (initial seqno) or set from Init Cookies
* Initialize S.GAR := S.ISS
* Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies
* Continue with S.state == RESPOND
* (* A Response packet will be generated in Step 11 *)
* Otherwise,
* Generate Reset(No Connection) unless P.type == Reset
* Drop packet and return
*
* NOTE: the check for the packet types is done in
* dccp_rcv_state_process
*/
if (dccp_rcv_state_process(sk, skb, dccp_hdr(skb), skb->len))
goto reset;
if (opt_skb)
goto ipv6_pktoptions;
return 0;
reset:
dccp_v6_ctl_send_reset(sk, skb);
discard:
if (opt_skb != NULL)
__kfree_skb(opt_skb);
kfree_skb(skb);
return 0;
/* Handling IPV6_PKTOPTIONS skb the similar
* way it's done for net/ipv6/tcp_ipv6.c
*/
ipv6_pktoptions:
if (!((1 << sk->sk_state) & (DCCPF_CLOSED | DCCPF_LISTEN))) {
if (np->rxopt.bits.rxinfo || np->rxopt.bits.rxoinfo)
np->mcast_oif = inet6_iif(opt_skb);
if (np->rxopt.bits.rxhlim || np->rxopt.bits.rxohlim)
np->mcast_hops = ipv6_hdr(opt_skb)->hop_limit;
if (np->rxopt.bits.rxflow || np->rxopt.bits.rxtclass)
np->rcv_flowinfo = ip6_flowinfo(ipv6_hdr(opt_skb));
if (np->repflow)
np->flow_label = ip6_flowlabel(ipv6_hdr(opt_skb));
if (ipv6_opt_accepted(sk, opt_skb,
&DCCP_SKB_CB(opt_skb)->header.h6)) {
skb_set_owner_r(opt_skb, sk);
memmove(IP6CB(opt_skb),
&DCCP_SKB_CB(opt_skb)->header.h6,
sizeof(struct inet6_skb_parm));
opt_skb = xchg(&np->pktoptions, opt_skb);
} else {
__kfree_skb(opt_skb);
opt_skb = xchg(&np->pktoptions, NULL);
}
}
kfree_skb(opt_skb);
return 0;
}
/**
* __skb_flow_dissect - extract the flow_keys struct and return it
* @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
* @flow_dissector: list of keys to dissect
* @target_container: target structure to put dissected values into
* @data: raw buffer pointer to the packet, if NULL use skb->data
* @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
* @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
* @hlen: packet header length, if @data is NULL use skb_headlen(skb)
*
* The function will try to retrieve individual keys into target specified
* by flow_dissector from either the skbuff or a raw buffer specified by the
* rest parameters.
*
* Caller must take care of zeroing target container memory.
*/
bool __skb_flow_dissect(const struct sk_buff *skb,
struct flow_dissector *flow_dissector,
void *target_container,
void *data, __be16 proto, int nhoff, int hlen,
unsigned int flags)
{
struct flow_dissector_key_control *key_control;
struct flow_dissector_key_basic *key_basic;
struct flow_dissector_key_addrs *key_addrs;
struct flow_dissector_key_ports *key_ports;
struct flow_dissector_key_icmp *key_icmp;
struct flow_dissector_key_tags *key_tags;
struct flow_dissector_key_vlan *key_vlan;
bool skip_vlan = false;
u8 ip_proto = 0;
bool ret;
if (!data) {
data = skb->data;
proto = skb_vlan_tag_present(skb) ?
skb->vlan_proto : skb->protocol;
nhoff = skb_network_offset(skb);
hlen = skb_headlen(skb);
}
/* It is ensured by skb_flow_dissector_init() that control key will
* be always present.
*/
key_control = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_CONTROL,
target_container);
/* It is ensured by skb_flow_dissector_init() that basic key will
* be always present.
*/
key_basic = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_BASIC,
target_container);
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
struct ethhdr *eth = eth_hdr(skb);
struct flow_dissector_key_eth_addrs *key_eth_addrs;
key_eth_addrs = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_ETH_ADDRS,
target_container);
memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
}
proto_again:
switch (proto) {
case htons(ETH_P_IP): {
const struct iphdr *iph;
struct iphdr _iph;
ip:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph || iph->ihl < 5)
goto out_bad;
nhoff += iph->ihl * 4;
ip_proto = iph->protocol;
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
key_addrs = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_IPV4_ADDRS,
target_container);
memcpy(&key_addrs->v4addrs, &iph->saddr,
sizeof(key_addrs->v4addrs));
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
}
if (ip_is_fragment(iph)) {
key_control->flags |= FLOW_DIS_IS_FRAGMENT;
if (iph->frag_off & htons(IP_OFFSET)) {
goto out_good;
} else {
key_control->flags |= FLOW_DIS_FIRST_FRAG;
if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
goto out_good;
}
}
__skb_flow_dissect_ipv4(skb, flow_dissector,
target_container, data, iph);
if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
goto out_good;
break;
}
case htons(ETH_P_IPV6): {
const struct ipv6hdr *iph;
struct ipv6hdr _iph;
ipv6:
iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
if (!iph)
goto out_bad;
ip_proto = iph->nexthdr;
nhoff += sizeof(struct ipv6hdr);
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
key_addrs = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_IPV6_ADDRS,
target_container);
memcpy(&key_addrs->v6addrs, &iph->saddr,
sizeof(key_addrs->v6addrs));
key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
}
if ((dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
(flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
ip6_flowlabel(iph)) {
__be32 flow_label = ip6_flowlabel(iph);
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
key_tags = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_FLOW_LABEL,
target_container);
key_tags->flow_label = ntohl(flow_label);
}
if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
goto out_good;
}
__skb_flow_dissect_ipv6(skb, flow_dissector,
target_container, data, iph);
if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
goto out_good;
break;
}
case htons(ETH_P_8021AD):
case htons(ETH_P_8021Q): {
const struct vlan_hdr *vlan;
struct vlan_hdr _vlan;
bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
if (vlan_tag_present)
proto = skb->protocol;
if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
data, hlen, &_vlan);
if (!vlan)
goto out_bad;
proto = vlan->h_vlan_encapsulated_proto;
nhoff += sizeof(*vlan);
if (skip_vlan)
goto proto_again;
}
skip_vlan = true;
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_VLAN)) {
key_vlan = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_VLAN,
target_container);
if (vlan_tag_present) {
key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
key_vlan->vlan_priority =
(skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
} else {
key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
VLAN_VID_MASK;
key_vlan->vlan_priority =
(ntohs(vlan->h_vlan_TCI) &
VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
}
}
goto proto_again;
}
case htons(ETH_P_PPP_SES): {
struct {
struct pppoe_hdr hdr;
__be16 proto;
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
goto out_bad;
proto = hdr->proto;
nhoff += PPPOE_SES_HLEN;
switch (proto) {
case htons(PPP_IP):
goto ip;
case htons(PPP_IPV6):
goto ipv6;
default:
goto out_bad;
}
}
case htons(ETH_P_TIPC): {
struct {
__be32 pre[3];
__be32 srcnode;
} *hdr, _hdr;
hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
if (!hdr)
goto out_bad;
if (dissector_uses_key(flow_dissector,
FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
key_addrs = skb_flow_dissector_target(flow_dissector,
FLOW_DISSECTOR_KEY_TIPC_ADDRS,
target_container);
key_addrs->tipcaddrs.srcnode = hdr->srcnode;
key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
}
goto out_good;
}
case htons(ETH_P_MPLS_UC):
case htons(ETH_P_MPLS_MC):
mpls:
switch (__skb_flow_dissect_mpls(skb, flow_dissector,
target_container, data,
nhoff, hlen)) {
case FLOW_DISSECT_RET_OUT_GOOD:
goto out_good;
case FLOW_DISSECT_RET_OUT_BAD:
default:
goto out_bad;
}
case htons(ETH_P_FCOE):
if ((hlen - nhoff) < FCOE_HEADER_LEN)
goto out_bad;
nhoff += FCOE_HEADER_LEN;
goto out_good;
case htons(ETH_P_ARP):
case htons(ETH_P_RARP):
switch (__skb_flow_dissect_arp(skb, flow_dissector,
target_container, data,
nhoff, hlen)) {
case FLOW_DISSECT_RET_OUT_GOOD:
goto out_good;
case FLOW_DISSECT_RET_OUT_BAD:
default:
goto out_bad;
}
default:
goto out_bad;
}
