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author | Alexander Duyck <alexander.h.duyck@intel.com> | 2014-09-05 19:20:26 -0400 |
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committer | David S. Miller <davem@davemloft.net> | 2014-09-05 17:47:02 -0700 |
commit | 56193d1bce2b2759cb4bdcc00cd05544894a0c90 (patch) | |
tree | 621b2ce35961049dd263c2f83aee3d9ec39ac686 /net/core/flow_dissector.c | |
parent | 2c048e646212f9880e6f201771a30daa963d7f8b (diff) | |
download | linux-stable-56193d1bce2b2759cb4bdcc00cd05544894a0c90.tar.gz linux-stable-56193d1bce2b2759cb4bdcc00cd05544894a0c90.tar.bz2 linux-stable-56193d1bce2b2759cb4bdcc00cd05544894a0c90.zip |
net: Add function for parsing the header length out of linear ethernet frames
This patch updates some of the flow_dissector api so that it can be used to
parse the length of ethernet buffers stored in fragments. Most of the
changes needed were to __skb_get_poff as it needed to be updated to support
sending a linear buffer instead of a skb.
I have split __skb_get_poff into two functions, the first is skb_get_poff
and it retains the functionality of the original __skb_get_poff. The other
function is __skb_get_poff which now works much like __skb_flow_dissect in
relation to skb_flow_dissect in that it provides the same functionality but
works with just a data buffer and hlen instead of needing an skb.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/flow_dissector.c')
-rw-r--r-- | net/core/flow_dissector.c | 46 |
1 files changed, 32 insertions, 14 deletions
diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 12f48ca7a0b0..8560dea58803 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -13,6 +13,7 @@ #include <linux/if_pppox.h> #include <linux/ppp_defs.h> #include <net/flow_keys.h> +#include <scsi/fc/fc_fcoe.h> /* copy saddr & daddr, possibly using 64bit load/store * Equivalent to : flow->src = iph->saddr; @@ -117,6 +118,13 @@ ipv6: flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); nhoff += sizeof(struct ipv6hdr); + /* skip the flow label processing if skb is NULL. The + * assumption here is that if there is no skb we are not + * looking for flow info as much as we are length. + */ + if (!skb) + break; + flow_label = ip6_flowlabel(iph); if (flow_label) { /* Awesome, IPv6 packet has a flow label so we can @@ -165,6 +173,9 @@ ipv6: return false; } } + case htons(ETH_P_FCOE): + flow->thoff = (u16)(nhoff + FCOE_HEADER_LEN); + /* fall through */ default: return false; } @@ -316,26 +327,18 @@ u16 __skb_tx_hash(const struct net_device *dev, struct sk_buff *skb, } EXPORT_SYMBOL(__skb_tx_hash); -/* __skb_get_poff() returns the offset to the payload as far as it could - * be dissected. The main user is currently BPF, so that we can dynamically - * truncate packets without needing to push actual payload to the user - * space and can analyze headers only, instead. - */ -u32 __skb_get_poff(const struct sk_buff *skb) +u32 __skb_get_poff(const struct sk_buff *skb, void *data, + const struct flow_keys *keys, int hlen) { - struct flow_keys keys; - u32 poff = 0; + u32 poff = keys->thoff; - if (!skb_flow_dissect(skb, &keys)) - return 0; - - poff += keys.thoff; - switch (keys.ip_proto) { + switch (keys->ip_proto) { case IPPROTO_TCP: { const struct tcphdr *tcph; struct tcphdr _tcph; - tcph = skb_header_pointer(skb, poff, sizeof(_tcph), &_tcph); + tcph = __skb_header_pointer(skb, poff, sizeof(_tcph), + data, hlen, &_tcph); if (!tcph) return poff; @@ -369,6 +372,21 @@ u32 __skb_get_poff(const struct sk_buff *skb) return poff; } +/* skb_get_poff() returns the offset to the payload as far as it could + * be dissected. The main user is currently BPF, so that we can dynamically + * truncate packets without needing to push actual payload to the user + * space and can analyze headers only, instead. + */ +u32 skb_get_poff(const struct sk_buff *skb) +{ + struct flow_keys keys; + + if (!skb_flow_dissect(skb, &keys)) + return 0; + + return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb)); +} + static inline int get_xps_queue(struct net_device *dev, struct sk_buff *skb) { #ifdef CONFIG_XPS |