Commit 51b8f812 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller

ipv6: exthdrs: get rid of indirect calls in ip6_parse_tlv()

As presented last month in our "BIG TCP" talk at netdev 0x15,
we plan using IPv6 jumbograms.

One of the minor problem we talked about is the fact that
ip6_parse_tlv() is currently using tables to list known tlvs,
thus using potentially expensive indirect calls.

While we could mitigate this cost using macros from
indirect_call_wrapper.h, we also can get rid of the tables
and let the compiler emit optimized code.
Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Cc: Justin Iurman <justin.iurman@uliege.be>
Cc: Coco Li <lixiaoyan@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d8517985
...@@ -55,19 +55,6 @@ ...@@ -55,19 +55,6 @@
#include <linux/uaccess.h> #include <linux/uaccess.h>
/*
* Parsing tlv encoded headers.
*
* Parsing function "func" returns true, if parsing succeed
* and false, if it failed.
* It MUST NOT touch skb->h.
*/
struct tlvtype_proc {
int type;
bool (*func)(struct sk_buff *skb, int offset);
};
/********************* /*********************
Generic functions Generic functions
*********************/ *********************/
...@@ -112,16 +99,23 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff, ...@@ -112,16 +99,23 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
return false; return false;
} }
static bool ipv6_hop_ra(struct sk_buff *skb, int optoff);
static bool ipv6_hop_ioam(struct sk_buff *skb, int optoff);
static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff);
static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff);
#if IS_ENABLED(CONFIG_IPV6_MIP6)
static bool ipv6_dest_hao(struct sk_buff *skb, int optoff);
#endif
/* Parse tlv encoded option header (hop-by-hop or destination) */ /* Parse tlv encoded option header (hop-by-hop or destination) */
static bool ip6_parse_tlv(const struct tlvtype_proc *procs, static bool ip6_parse_tlv(bool hopbyhop,
struct sk_buff *skb, struct sk_buff *skb,
int max_count) int max_count)
{ {
int len = (skb_transport_header(skb)[1] + 1) << 3; int len = (skb_transport_header(skb)[1] + 1) << 3;
const unsigned char *nh = skb_network_header(skb); const unsigned char *nh = skb_network_header(skb);
int off = skb_network_header_len(skb); int off = skb_network_header_len(skb);
const struct tlvtype_proc *curr;
bool disallow_unknowns = false; bool disallow_unknowns = false;
int tlv_count = 0; int tlv_count = 0;
int padlen = 0; int padlen = 0;
...@@ -176,20 +170,45 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs, ...@@ -176,20 +170,45 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
if (tlv_count > max_count) if (tlv_count > max_count)
goto bad; goto bad;
for (curr = procs; curr->type >= 0; curr++) { if (hopbyhop) {
if (curr->type == nh[off]) { switch (nh[off]) {
/* type specific length/alignment case IPV6_TLV_ROUTERALERT:
checks will be performed in the if (!ipv6_hop_ra(skb, off))
func(). */ return false;
if (curr->func(skb, off) == false) break;
case IPV6_TLV_IOAM:
if (!ipv6_hop_ioam(skb, off))
return false;
break;
case IPV6_TLV_JUMBO:
if (!ipv6_hop_jumbo(skb, off))
return false;
break;
case IPV6_TLV_CALIPSO:
if (!ipv6_hop_calipso(skb, off))
return false;
break;
default:
if (!ip6_tlvopt_unknown(skb, off,
disallow_unknowns))
return false; return false;
break; break;
} }
} } else {
if (curr->type < 0 && switch (nh[off]) {
!ip6_tlvopt_unknown(skb, off, disallow_unknowns)) #if IS_ENABLED(CONFIG_IPV6_MIP6)
case IPV6_TLV_HAO:
if (!ipv6_dest_hao(skb, off))
return false; return false;
break;
#endif
default:
if (!ip6_tlvopt_unknown(skb, off,
disallow_unknowns))
return false;
break;
}
}
padlen = 0; padlen = 0;
} }
off += optlen; off += optlen;
...@@ -267,16 +286,6 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff) ...@@ -267,16 +286,6 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
} }
#endif #endif
static const struct tlvtype_proc tlvprocdestopt_lst[] = {
#if IS_ENABLED(CONFIG_IPV6_MIP6)
{
.type = IPV6_TLV_HAO,
.func = ipv6_dest_hao,
},
#endif
{-1, NULL}
};
static int ipv6_destopt_rcv(struct sk_buff *skb) static int ipv6_destopt_rcv(struct sk_buff *skb)
{ {
struct inet6_dev *idev = __in6_dev_get(skb->dev); struct inet6_dev *idev = __in6_dev_get(skb->dev);
...@@ -307,8 +316,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) ...@@ -307,8 +316,7 @@ static int ipv6_destopt_rcv(struct sk_buff *skb)
dstbuf = opt->dst1; dstbuf = opt->dst1;
#endif #endif
if (ip6_parse_tlv(tlvprocdestopt_lst, skb, if (ip6_parse_tlv(false, skb, net->ipv6.sysctl.max_dst_opts_cnt)) {
net->ipv6.sysctl.max_dst_opts_cnt)) {
skb->transport_header += extlen; skb->transport_header += extlen;
opt = IP6CB(skb); opt = IP6CB(skb);
#if IS_ENABLED(CONFIG_IPV6_MIP6) #if IS_ENABLED(CONFIG_IPV6_MIP6)
...@@ -1051,26 +1059,6 @@ static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff) ...@@ -1051,26 +1059,6 @@ static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
return false; return false;
} }
static const struct tlvtype_proc tlvprochopopt_lst[] = {
{
.type = IPV6_TLV_ROUTERALERT,
.func = ipv6_hop_ra,
},
{
.type = IPV6_TLV_IOAM,
.func = ipv6_hop_ioam,
},
{
.type = IPV6_TLV_JUMBO,
.func = ipv6_hop_jumbo,
},
{
.type = IPV6_TLV_CALIPSO,
.func = ipv6_hop_calipso,
},
{ -1, }
};
int ipv6_parse_hopopts(struct sk_buff *skb) int ipv6_parse_hopopts(struct sk_buff *skb)
{ {
struct inet6_skb_parm *opt = IP6CB(skb); struct inet6_skb_parm *opt = IP6CB(skb);
...@@ -1096,8 +1084,7 @@ int ipv6_parse_hopopts(struct sk_buff *skb) ...@@ -1096,8 +1084,7 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
goto fail_and_free; goto fail_and_free;
opt->flags |= IP6SKB_HOPBYHOP; opt->flags |= IP6SKB_HOPBYHOP;
if (ip6_parse_tlv(tlvprochopopt_lst, skb, if (ip6_parse_tlv(true, skb, net->ipv6.sysctl.max_hbh_opts_cnt)) {
net->ipv6.sysctl.max_hbh_opts_cnt)) {
skb->transport_header += extlen; skb->transport_header += extlen;
opt = IP6CB(skb); opt = IP6CB(skb);
opt->nhoff = sizeof(struct ipv6hdr); opt->nhoff = sizeof(struct ipv6hdr);
......
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