ipvs: avoid indirect calls when calculating checksums

The function pointer ip_vs_protocol->csum_check is only used in protocol
specific code, and never in the generic one.
Remove the function pointer from struct ip_vs_protocol and call the
checksum functions directly.
This reduces the performance impact of the Spectre mitigation, and
should give a small improvement even with RETPOLINES disabled.

Signed-off-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Acked-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index a0d2e0b..047f9a5 100644 (file)
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -453,9 +453,6 @@ struct ip_vs_protocol {
        int (*dnat_handler)(struct sk_buff *skb, struct ip_vs_protocol *pp,
                            struct ip_vs_conn *cp, struct ip_vs_iphdr *iph);
 
-       int (*csum_check)(int af, struct sk_buff *skb,
-                         struct ip_vs_protocol *pp);
-
        const char *(*state_name)(int state);
 
        void (*state_transition)(struct ip_vs_conn *cp, int direction,

diff --git a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
index 5320d39..480598c 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_ah_esp.c
@@ -129,7 +129,6 @@ struct ip_vs_protocol ip_vs_protocol_ah = {
        .conn_out_get =         ah_esp_conn_out_get,
        .snat_handler =         NULL,
        .dnat_handler =         NULL,
-       .csum_check =           NULL,
        .state_transition =     NULL,
        .register_app =         NULL,
        .unregister_app =       NULL,
@@ -152,7 +151,6 @@ struct ip_vs_protocol ip_vs_protocol_esp = {
        .conn_out_get =         ah_esp_conn_out_get,
        .snat_handler =         NULL,
        .dnat_handler =         NULL,
-       .csum_check =           NULL,
        .state_transition =     NULL,
        .register_app =         NULL,
        .unregister_app =       NULL,

diff --git a/net/netfilter/ipvs/ip_vs_proto_sctp.c b/net/netfilter/ipvs/ip_vs_proto_sctp.c
index b0cd7d0..bc3d162 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_proto_sctp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_sctp.c
@@ -10,6 +10,9 @@
 #include <net/ip_vs.h>
 
 static int
+sctp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp);
+
+static int
 sctp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
                   struct ip_vs_proto_data *pd,
                   int *verdict, struct ip_vs_conn **cpp,
@@ -105,7 +108,7 @@ sctp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!sctp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /* Call application helper if needed */
@@ -152,7 +155,7 @@ sctp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!sctp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /* Call application helper if needed */
@@ -587,7 +590,6 @@ struct ip_vs_protocol ip_vs_protocol_sctp = {
        .conn_out_get   = ip_vs_conn_out_get_proto,
        .snat_handler   = sctp_snat_handler,
        .dnat_handler   = sctp_dnat_handler,
-       .csum_check     = sctp_csum_check,
        .state_name     = sctp_state_name,
        .state_transition = sctp_state_transition,
        .app_conn_bind  = sctp_app_conn_bind,

diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c
index 1770fc6..6a275f9 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_proto_tcp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c
@@ -32,6 +32,9 @@
 #include <net/ip_vs.h>
 
 static int
+tcp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp);
+
+static int
 tcp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
                  struct ip_vs_proto_data *pd,
                  int *verdict, struct ip_vs_conn **cpp,
@@ -166,7 +169,7 @@ tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!tcp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /* Call application helper if needed */
@@ -192,7 +195,7 @@ tcp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr,
                                     cp->dport, cp->vport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
-                       skb->ip_summed = (cp->app && pp->csum_check) ?
+                       skb->ip_summed = cp->app ?
                                         CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
        } else {
                /* full checksum calculation */
@@ -244,7 +247,7 @@ tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!tcp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -275,7 +278,7 @@ tcp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr,
                                     cp->vport, cp->dport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
-                       skb->ip_summed = (cp->app && pp->csum_check) ?
+                       skb->ip_summed = cp->app ?
                                         CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
        } else {
                /* full checksum calculation */
@@ -736,7 +739,6 @@ struct ip_vs_protocol ip_vs_protocol_tcp = {
        .conn_out_get =         ip_vs_conn_out_get_proto,
        .snat_handler =         tcp_snat_handler,
        .dnat_handler =         tcp_dnat_handler,
-       .csum_check =           tcp_csum_check,
        .state_name =           tcp_state_name,
        .state_transition =     tcp_state_transition,
        .app_conn_bind =        tcp_app_conn_bind,

diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c b/net/netfilter/ipvs/ip_vs_proto_udp.c
index 0f53c49..3285718 100644 (file)
--- a/net/netfilter/ipvs/ip_vs_proto_udp.c
+++ b/net/netfilter/ipvs/ip_vs_proto_udp.c
@@ -29,6 +29,9 @@
 #include <net/ip6_checksum.h>
 
 static int
+udp_csum_check(int af, struct sk_buff *skb, struct ip_vs_protocol *pp);
+
+static int
 udp_conn_schedule(struct netns_ipvs *ipvs, int af, struct sk_buff *skb,
                  struct ip_vs_proto_data *pd,
                  int *verdict, struct ip_vs_conn **cpp,
@@ -156,7 +159,7 @@ udp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!udp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -186,7 +189,7 @@ udp_snat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr,
                                     cp->dport, cp->vport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
-                       skb->ip_summed = (cp->app && pp->csum_check) ?
+                       skb->ip_summed = cp->app ?
                                         CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
        } else {
                /* full checksum calculation */
@@ -239,7 +242,7 @@ udp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                int ret;
 
                /* Some checks before mangling */
-               if (pp->csum_check && !pp->csum_check(cp->af, skb, pp))
+               if (!udp_csum_check(cp->af, skb, pp))
                        return 0;
 
                /*
@@ -270,7 +273,7 @@ udp_dnat_handler(struct sk_buff *skb, struct ip_vs_protocol *pp,
                udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr,
                                     cp->vport, cp->dport);
                if (skb->ip_summed == CHECKSUM_COMPLETE)
-                       skb->ip_summed = (cp->app && pp->csum_check) ?
+                       skb->ip_summed = cp->app ?
                                         CHECKSUM_UNNECESSARY : CHECKSUM_NONE;
        } else {
                /* full checksum calculation */
@@ -494,7 +497,6 @@ struct ip_vs_protocol ip_vs_protocol_udp = {
        .conn_out_get =         ip_vs_conn_out_get_proto,
        .snat_handler =         udp_snat_handler,
        .dnat_handler =         udp_dnat_handler,
-       .csum_check =           udp_csum_check,
        .state_transition =     udp_state_transition,
        .state_name =           udp_state_name,
        .register_app =         udp_register_app,