From 8b27b10f5863a5b63e46304a71aa01463d1efac4 Mon Sep 17 00:00:00 2001 From: Julian Anastasov Date: Sun, 17 Oct 2010 16:17:20 +0300 Subject: [PATCH] ipvs: optimize checksums for apps Avoid full checksum calculation for apps that can provide info whether csum was broken after payload mangling. For now only ip_vs_ftp mangles payload and it updates the csum, so the full recalculation is avoided for all packets. Add CHECKSUM_UNNECESSARY for snat_handler (TCP and UDP). It is needed to support SNAT from local address for the case when csum is fully recalculated. Signed-off-by: Julian Anastasov Signed-off-by: Simon Horman --- include/net/ip_vs.h | 12 +++++++++-- net/netfilter/ipvs/ip_vs_ftp.c | 7 ++++++- net/netfilter/ipvs/ip_vs_proto_tcp.c | 31 ++++++++++++++++++++++------ net/netfilter/ipvs/ip_vs_proto_udp.c | 31 ++++++++++++++++++++++------ 4 files changed, 66 insertions(+), 15 deletions(-) diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h index 6e8a6192e574..adcdba9dd183 100644 --- a/include/net/ip_vs.h +++ b/include/net/ip_vs.h @@ -597,11 +597,19 @@ struct ip_vs_app { __be16 port; /* port number in net order */ atomic_t usecnt; /* usage counter */ - /* output hook: return false if can't linearize. diff set for TCP. */ + /* + * output hook: Process packet in inout direction, diff set for TCP. + * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok, + * 2=Mangled but checksum was not updated + */ int (*pkt_out)(struct ip_vs_app *, struct ip_vs_conn *, struct sk_buff *, int *diff); - /* input hook: return false if can't linearize. diff set for TCP. */ + /* + * input hook: Process packet in outin direction, diff set for TCP. + * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok, + * 2=Mangled but checksum was not updated + */ int (*pkt_in)(struct ip_vs_app *, struct ip_vs_conn *, struct sk_buff *, int *diff); diff --git a/net/netfilter/ipvs/ip_vs_ftp.c b/net/netfilter/ipvs/ip_vs_ftp.c index 090889a3b3af..75455000ad1c 100644 --- a/net/netfilter/ipvs/ip_vs_ftp.c +++ b/net/netfilter/ipvs/ip_vs_ftp.c @@ -242,9 +242,14 @@ static int ip_vs_ftp_out(struct ip_vs_app *app, struct ip_vs_conn *cp, ret = nf_nat_mangle_tcp_packet(skb, ct, ctinfo, start-data, end-start, buf, buf_len); - if (ret) + if (ret) { ip_vs_nfct_expect_related(skb, ct, n_cp, IPPROTO_TCP, 0, 0); + if (skb->ip_summed == CHECKSUM_COMPLETE) + skb->ip_summed = CHECKSUM_UNNECESSARY; + /* csum is updated */ + ret = 1; + } } /* diff --git a/net/netfilter/ipvs/ip_vs_proto_tcp.c b/net/netfilter/ipvs/ip_vs_proto_tcp.c index 318d011036db..64dc2954cf78 100644 --- a/net/netfilter/ipvs/ip_vs_proto_tcp.c +++ b/net/netfilter/ipvs/ip_vs_proto_tcp.c @@ -120,6 +120,7 @@ tcp_snat_handler(struct sk_buff *skb, struct tcphdr *tcph; unsigned int tcphoff; int oldlen; + int payload_csum = 0; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -134,13 +135,20 @@ tcp_snat_handler(struct sk_buff *skb, return 0; if (unlikely(cp->app != NULL)) { + int ret; + /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; /* Call application helper if needed */ - if (!ip_vs_app_pkt_out(cp, skb)) + if (!(ret = ip_vs_app_pkt_out(cp, skb))) return 0; + /* ret=2: csum update is needed after payload mangling */ + if (ret == 1) + oldlen = skb->len - tcphoff; + else + payload_csum = 1; } tcph = (void *)skb_network_header(skb) + tcphoff; @@ -151,12 +159,13 @@ tcp_snat_handler(struct sk_buff *skb, tcp_partial_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, htons(oldlen), htons(skb->len - tcphoff)); - } else if (!cp->app) { + } else if (!payload_csum) { /* Only port and addr are changed, do fast csum update */ tcp_fast_csum_update(cp->af, tcph, &cp->daddr, &cp->vaddr, cp->dport, cp->vport); if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->ip_summed = CHECKSUM_NONE; + skb->ip_summed = (cp->app && pp->csum_check) ? + CHECKSUM_UNNECESSARY : CHECKSUM_NONE; } else { /* full checksum calculation */ tcph->check = 0; @@ -174,6 +183,7 @@ tcp_snat_handler(struct sk_buff *skb, skb->len - tcphoff, cp->protocol, skb->csum); + skb->ip_summed = CHECKSUM_UNNECESSARY; IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", pp->name, tcph->check, @@ -190,6 +200,7 @@ tcp_dnat_handler(struct sk_buff *skb, struct tcphdr *tcph; unsigned int tcphoff; int oldlen; + int payload_csum = 0; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -204,6 +215,8 @@ tcp_dnat_handler(struct sk_buff *skb, return 0; if (unlikely(cp->app != NULL)) { + int ret; + /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; @@ -212,8 +225,13 @@ tcp_dnat_handler(struct sk_buff *skb, * Attempt ip_vs_app call. * It will fix ip_vs_conn and iph ack_seq stuff */ - if (!ip_vs_app_pkt_in(cp, skb)) + if (!(ret = ip_vs_app_pkt_in(cp, skb))) return 0; + /* ret=2: csum update is needed after payload mangling */ + if (ret == 1) + oldlen = skb->len - tcphoff; + else + payload_csum = 1; } tcph = (void *)skb_network_header(skb) + tcphoff; @@ -226,12 +244,13 @@ tcp_dnat_handler(struct sk_buff *skb, tcp_partial_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, htons(oldlen), htons(skb->len - tcphoff)); - } else if (!cp->app) { + } else if (!payload_csum) { /* Only port and addr are changed, do fast csum update */ tcp_fast_csum_update(cp->af, tcph, &cp->vaddr, &cp->daddr, cp->vport, cp->dport); if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->ip_summed = CHECKSUM_NONE; + skb->ip_summed = (cp->app && pp->csum_check) ? + CHECKSUM_UNNECESSARY : CHECKSUM_NONE; } else { /* full checksum calculation */ tcph->check = 0; diff --git a/net/netfilter/ipvs/ip_vs_proto_udp.c b/net/netfilter/ipvs/ip_vs_proto_udp.c index f9290893bd93..9c558c40bfbb 100644 --- a/net/netfilter/ipvs/ip_vs_proto_udp.c +++ b/net/netfilter/ipvs/ip_vs_proto_udp.c @@ -121,6 +121,7 @@ udp_snat_handler(struct sk_buff *skb, struct udphdr *udph; unsigned int udphoff; int oldlen; + int payload_csum = 0; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -135,6 +136,8 @@ udp_snat_handler(struct sk_buff *skb, return 0; if (unlikely(cp->app != NULL)) { + int ret; + /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; @@ -142,8 +145,13 @@ udp_snat_handler(struct sk_buff *skb, /* * Call application helper if needed */ - if (!ip_vs_app_pkt_out(cp, skb)) + if (!(ret = ip_vs_app_pkt_out(cp, skb))) return 0; + /* ret=2: csum update is needed after payload mangling */ + if (ret == 1) + oldlen = skb->len - udphoff; + else + payload_csum = 1; } udph = (void *)skb_network_header(skb) + udphoff; @@ -156,12 +164,13 @@ udp_snat_handler(struct sk_buff *skb, udp_partial_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr, htons(oldlen), htons(skb->len - udphoff)); - } else if (!cp->app && (udph->check != 0)) { + } else if (!payload_csum && (udph->check != 0)) { /* Only port and addr are changed, do fast csum update */ udp_fast_csum_update(cp->af, udph, &cp->daddr, &cp->vaddr, cp->dport, cp->vport); if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->ip_summed = CHECKSUM_NONE; + skb->ip_summed = (cp->app && pp->csum_check) ? + CHECKSUM_UNNECESSARY : CHECKSUM_NONE; } else { /* full checksum calculation */ udph->check = 0; @@ -181,6 +190,7 @@ udp_snat_handler(struct sk_buff *skb, skb->csum); if (udph->check == 0) udph->check = CSUM_MANGLED_0; + skb->ip_summed = CHECKSUM_UNNECESSARY; IP_VS_DBG(11, "O-pkt: %s O-csum=%d (+%zd)\n", pp->name, udph->check, (char*)&(udph->check) - (char*)udph); @@ -196,6 +206,7 @@ udp_dnat_handler(struct sk_buff *skb, struct udphdr *udph; unsigned int udphoff; int oldlen; + int payload_csum = 0; #ifdef CONFIG_IP_VS_IPV6 if (cp->af == AF_INET6) @@ -210,6 +221,8 @@ udp_dnat_handler(struct sk_buff *skb, return 0; if (unlikely(cp->app != NULL)) { + int ret; + /* Some checks before mangling */ if (pp->csum_check && !pp->csum_check(cp->af, skb, pp)) return 0; @@ -218,8 +231,13 @@ udp_dnat_handler(struct sk_buff *skb, * Attempt ip_vs_app call. * It will fix ip_vs_conn */ - if (!ip_vs_app_pkt_in(cp, skb)) + if (!(ret = ip_vs_app_pkt_in(cp, skb))) return 0; + /* ret=2: csum update is needed after payload mangling */ + if (ret == 1) + oldlen = skb->len - udphoff; + else + payload_csum = 1; } udph = (void *)skb_network_header(skb) + udphoff; @@ -232,12 +250,13 @@ udp_dnat_handler(struct sk_buff *skb, udp_partial_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr, htons(oldlen), htons(skb->len - udphoff)); - } else if (!cp->app && (udph->check != 0)) { + } else if (!payload_csum && (udph->check != 0)) { /* Only port and addr are changed, do fast csum update */ udp_fast_csum_update(cp->af, udph, &cp->vaddr, &cp->daddr, cp->vport, cp->dport); if (skb->ip_summed == CHECKSUM_COMPLETE) - skb->ip_summed = CHECKSUM_NONE; + skb->ip_summed = (cp->app && pp->csum_check) ? + CHECKSUM_UNNECESSARY : CHECKSUM_NONE; } else { /* full checksum calculation */ udph->check = 0; -- 2.39.5