From: Rick Jones Date: Mon, 17 Nov 2014 22:04:29 +0000 (-0800) Subject: icmp: Remove some spurious dropped packet profile hits from the ICMP path X-Git-Tag: v4.9.8~5202^2~168 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e3e3217029a35c579bf100998b43976d0b1cb8d7;p=platform%2Fkernel%2Flinux-rpi3.git icmp: Remove some spurious dropped packet profile hits from the ICMP path If icmp_rcv() has successfully processed the incoming ICMP datagram, we should use consume_skb() rather than kfree_skb() because a hit on the likes of perf -e skb:kfree_skb is not called-for. Signed-off-by: Rick Jones Signed-off-by: David S. Miller --- diff --git a/include/net/ping.h b/include/net/ping.h index 026479b..f074060 100644 --- a/include/net/ping.h +++ b/include/net/ping.h @@ -82,7 +82,7 @@ int ping_common_sendmsg(int family, struct msghdr *msg, size_t len, int ping_v6_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, size_t len); int ping_queue_rcv_skb(struct sock *sk, struct sk_buff *skb); -void ping_rcv(struct sk_buff *skb); +bool ping_rcv(struct sk_buff *skb); #ifdef CONFIG_PROC_FS struct ping_seq_afinfo { diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 36b7bfa..36f5584 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -190,7 +190,7 @@ EXPORT_SYMBOL(icmp_err_convert); */ struct icmp_control { - void (*handler)(struct sk_buff *skb); + bool (*handler)(struct sk_buff *skb); short error; /* This ICMP is classed as an error message */ }; @@ -746,7 +746,7 @@ static bool icmp_tag_validation(int proto) * ICMP_PARAMETERPROB. */ -static void icmp_unreach(struct sk_buff *skb) +static bool icmp_unreach(struct sk_buff *skb) { const struct iphdr *iph; struct icmphdr *icmph; @@ -839,10 +839,10 @@ static void icmp_unreach(struct sk_buff *skb) icmp_socket_deliver(skb, info); out: - return; + return true; out_err: ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS); - goto out; + return false; } @@ -850,17 +850,20 @@ out_err: * Handle ICMP_REDIRECT. */ -static void icmp_redirect(struct sk_buff *skb) +static bool icmp_redirect(struct sk_buff *skb) { if (skb->len < sizeof(struct iphdr)) { ICMP_INC_STATS_BH(dev_net(skb->dev), ICMP_MIB_INERRORS); - return; + return false; } - if (!pskb_may_pull(skb, sizeof(struct iphdr))) - return; + if (!pskb_may_pull(skb, sizeof(struct iphdr))) { + /* there aught to be a stat */ + return false; + } icmp_socket_deliver(skb, icmp_hdr(skb)->un.gateway); + return true; } /* @@ -875,7 +878,7 @@ static void icmp_redirect(struct sk_buff *skb) * See also WRT handling of options once they are done and working. */ -static void icmp_echo(struct sk_buff *skb) +static bool icmp_echo(struct sk_buff *skb) { struct net *net; @@ -891,6 +894,8 @@ static void icmp_echo(struct sk_buff *skb) icmp_param.head_len = sizeof(struct icmphdr); icmp_reply(&icmp_param, skb); } + /* should there be an ICMP stat for ignored echos? */ + return true; } /* @@ -900,7 +905,7 @@ static void icmp_echo(struct sk_buff *skb) * MUST be accurate to a few minutes. * MUST be updated at least at 15Hz. */ -static void icmp_timestamp(struct sk_buff *skb) +static bool icmp_timestamp(struct sk_buff *skb) { struct timespec tv; struct icmp_bxm icmp_param; @@ -927,15 +932,17 @@ static void icmp_timestamp(struct sk_buff *skb) icmp_param.data_len = 0; icmp_param.head_len = sizeof(struct icmphdr) + 12; icmp_reply(&icmp_param, skb); -out: - return; + return true; + out_err: ICMP_INC_STATS_BH(dev_net(skb_dst(skb)->dev), ICMP_MIB_INERRORS); - goto out; + return false; } -static void icmp_discard(struct sk_buff *skb) +static bool icmp_discard(struct sk_buff *skb) { + /* pretend it was a success */ + return true; } /* @@ -946,6 +953,7 @@ int icmp_rcv(struct sk_buff *skb) struct icmphdr *icmph; struct rtable *rt = skb_rtable(skb); struct net *net = dev_net(rt->dst.dev); + bool success; if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb)) { struct sec_path *sp = skb_sec_path(skb); @@ -1012,7 +1020,12 @@ int icmp_rcv(struct sk_buff *skb) } } - icmp_pointers[icmph->type].handler(skb); + success = icmp_pointers[icmph->type].handler(skb); + + if (success) { + consume_skb(skb); + return 0; + } drop: kfree_skb(skb); diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 736236c..ce2920f 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -955,7 +955,7 @@ EXPORT_SYMBOL_GPL(ping_queue_rcv_skb); * All we need to do is get the socket. */ -void ping_rcv(struct sk_buff *skb) +bool ping_rcv(struct sk_buff *skb) { struct sock *sk; struct net *net = dev_net(skb->dev); @@ -974,11 +974,11 @@ void ping_rcv(struct sk_buff *skb) pr_debug("rcv on socket %p\n", sk); ping_queue_rcv_skb(sk, skb_get(skb)); sock_put(sk); - return; + return true; } pr_debug("no socket, dropping\n"); - /* We're called from icmp_rcv(). kfree_skb() is done there. */ + return false; } EXPORT_SYMBOL_GPL(ping_rcv); diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 0929340..39b3ff9 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -679,6 +679,7 @@ static int icmpv6_rcv(struct sk_buff *skb) const struct in6_addr *saddr, *daddr; struct icmp6hdr *hdr; u8 type; + bool success = false; if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) { struct sec_path *sp = skb_sec_path(skb); @@ -726,7 +727,7 @@ static int icmpv6_rcv(struct sk_buff *skb) break; case ICMPV6_ECHO_REPLY: - ping_rcv(skb); + success = ping_rcv(skb); break; case ICMPV6_PKT_TOOBIG: @@ -790,7 +791,14 @@ static int icmpv6_rcv(struct sk_buff *skb) icmpv6_notify(skb, type, hdr->icmp6_code, hdr->icmp6_mtu); } - kfree_skb(skb); + /* until the v6 path can be better sorted assume failure and + * preserve the status quo behaviour for the rest of the paths to here + */ + if (success) + consume_skb(skb); + else + kfree_skb(skb); + return 0; csum_error: