Initial import

1 files changed, 584 insertions, 0 deletions

diff --git a/net/sched/act_csum.c b/net/sched/act_csum.c
new file mode 100644
index 000000000..4cd5cf1ae
--- /dev/null
+++ b/net/sched/act_csum.c
@@ -0,0 +1,584 @@
+/*
+ * Checksum updating actions
+ *
+ * Copyright (c) 2010 Gregoire Baron <baronchon@n7mm.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+
+#include <linux/netlink.h>
+#include <net/netlink.h>
+#include <linux/rtnetlink.h>
+
+#include <linux/skbuff.h>
+
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/icmp.h>
+#include <linux/icmpv6.h>
+#include <linux/igmp.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/ip6_checksum.h>
+
+#include <net/act_api.h>
+
+#include <linux/tc_act/tc_csum.h>
+#include <net/tc_act/tc_csum.h>
+
+#define CSUM_TAB_MASK 15
+
+static const struct nla_policy csum_policy[TCA_CSUM_MAX + 1] = {
+	[TCA_CSUM_PARMS] = { .len = sizeof(struct tc_csum), },
+};
+
+static int tcf_csum_init(struct net *n, struct nlattr *nla, struct nlattr *est,
+			 struct tc_action *a, int ovr, int bind)
+{
+	struct nlattr *tb[TCA_CSUM_MAX + 1];
+	struct tc_csum *parm;
+	struct tcf_csum *p;
+	int ret = 0, err;
+
+	if (nla == NULL)
+		return -EINVAL;
+
+	err = nla_parse_nested(tb, TCA_CSUM_MAX, nla, csum_policy);
+	if (err < 0)
+		return err;
+
+	if (tb[TCA_CSUM_PARMS] == NULL)
+		return -EINVAL;
+	parm = nla_data(tb[TCA_CSUM_PARMS]);
+
+	if (!tcf_hash_check(parm->index, a, bind)) {
+		ret = tcf_hash_create(parm->index, est, a, sizeof(*p), bind);
+		if (ret)
+			return ret;
+		ret = ACT_P_CREATED;
+	} else {
+		if (bind)/* dont override defaults */
+			return 0;
+		tcf_hash_release(a, bind);
+		if (!ovr)
+			return -EEXIST;
+	}
+
+	p = to_tcf_csum(a);
+	spin_lock_bh(&p->tcf_lock);
+	p->tcf_action = parm->action;
+	p->update_flags = parm->update_flags;
+	spin_unlock_bh(&p->tcf_lock);
+
+	if (ret == ACT_P_CREATED)
+		tcf_hash_insert(a);
+
+	return ret;
+}
+
+/**
+ * tcf_csum_skb_nextlayer - Get next layer pointer
+ * @skb: sk_buff to use
+ * @ihl: previous summed headers length
+ * @ipl: complete packet length
+ * @jhl: next header length
+ *
+ * Check the expected next layer availability in the specified sk_buff.
+ * Return the next layer pointer if pass, NULL otherwise.
+ */
+static void *tcf_csum_skb_nextlayer(struct sk_buff *skb,
+				    unsigned int ihl, unsigned int ipl,
+				    unsigned int jhl)
+{
+	int ntkoff = skb_network_offset(skb);
+	int hl = ihl + jhl;
+
+	if (!pskb_may_pull(skb, ipl + ntkoff) || (ipl < hl) ||
+	    (skb_cloned(skb) &&
+	     !skb_clone_writable(skb, hl + ntkoff) &&
+	     pskb_expand_head(skb, 0, 0, GFP_ATOMIC)))
+		return NULL;
+	else
+		return (void *)(skb_network_header(skb) + ihl);
+}
+
+static int tcf_csum_ipv4_icmp(struct sk_buff *skb,
+			      unsigned int ihl, unsigned int ipl)
+{
+	struct icmphdr *icmph;
+
+	icmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmph));
+	if (icmph == NULL)
+		return 0;
+
+	icmph->checksum = 0;
+	skb->csum = csum_partial(icmph, ipl - ihl, 0);
+	icmph->checksum = csum_fold(skb->csum);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 1;
+}
+
+static int tcf_csum_ipv4_igmp(struct sk_buff *skb,
+			      unsigned int ihl, unsigned int ipl)
+{
+	struct igmphdr *igmph;
+
+	igmph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*igmph));
+	if (igmph == NULL)
+		return 0;
+
+	igmph->csum = 0;
+	skb->csum = csum_partial(igmph, ipl - ihl, 0);
+	igmph->csum = csum_fold(skb->csum);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 1;
+}
+
+static int tcf_csum_ipv6_icmp(struct sk_buff *skb,
+			      unsigned int ihl, unsigned int ipl)
+{
+	struct icmp6hdr *icmp6h;
+	const struct ipv6hdr *ip6h;
+
+	icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
+	if (icmp6h == NULL)
+		return 0;
+
+	ip6h = ipv6_hdr(skb);
+	icmp6h->icmp6_cksum = 0;
+	skb->csum = csum_partial(icmp6h, ipl - ihl, 0);
+	icmp6h->icmp6_cksum = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+					      ipl - ihl, IPPROTO_ICMPV6,
+					      skb->csum);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 1;
+}
+
+static int tcf_csum_ipv4_tcp(struct sk_buff *skb,
+			     unsigned int ihl, unsigned int ipl)
+{
+	struct tcphdr *tcph;
+	const struct iphdr *iph;
+
+	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
+	if (tcph == NULL)
+		return 0;
+
+	iph = ip_hdr(skb);
+	tcph->check = 0;
+	skb->csum = csum_partial(tcph, ipl - ihl, 0);
+	tcph->check = tcp_v4_check(ipl - ihl,
+				   iph->saddr, iph->daddr, skb->csum);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 1;
+}
+
+static int tcf_csum_ipv6_tcp(struct sk_buff *skb,
+			     unsigned int ihl, unsigned int ipl)
+{
+	struct tcphdr *tcph;
+	const struct ipv6hdr *ip6h;
+
+	tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
+	if (tcph == NULL)
+		return 0;
+
+	ip6h = ipv6_hdr(skb);
+	tcph->check = 0;
+	skb->csum = csum_partial(tcph, ipl - ihl, 0);
+	tcph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,
+				      ipl - ihl, IPPROTO_TCP,
+				      skb->csum);
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+	return 1;
+}
+
+static int tcf_csum_ipv4_udp(struct sk_buff *skb,
+			     unsigned int ihl, unsigned int ipl, int udplite)
+{
+	struct udphdr *udph;
+	const struct iphdr *iph;
+	u16 ul;
+
+	/*
+	 * Support both UDP and UDPLITE checksum algorithms, Don't use
+	 * udph->len to get the real length without any protocol check,
+	 * UDPLITE uses udph->len for another thing,
+	 * Use iph->tot_len, or just ipl.
+	 */
+
+	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
+	if (udph == NULL)
+		return 0;
+
+	iph = ip_hdr(skb);
+	ul = ntohs(udph->len);
+
+	if (udplite || udph->check) {
+
+		udph->check = 0;
+
+		if (udplite) {
+			if (ul == 0)
+				skb->csum = csum_partial(udph, ipl - ihl, 0);
+			else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
+				skb->csum = csum_partial(udph, ul, 0);
+			else
+				goto ignore_obscure_skb;
+		} else {
+			if (ul != ipl - ihl)
+				goto ignore_obscure_skb;
+
+			skb->csum = csum_partial(udph, ul, 0);
+		}
+
+		udph->check = csum_tcpudp_magic(iph->saddr, iph->daddr,
+						ul, iph->protocol,
+						skb->csum);
+
+		if (!udph->check)
+			udph->check = CSUM_MANGLED_0;
+	}
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+ignore_obscure_skb:
+	return 1;
+}
+
+static int tcf_csum_ipv6_udp(struct sk_buff *skb,
+			     unsigned int ihl, unsigned int ipl, int udplite)
+{
+	struct udphdr *udph;
+	const struct ipv6hdr *ip6h;
+	u16 ul;
+
+	/*
+	 * Support both UDP and UDPLITE checksum algorithms, Don't use
+	 * udph->len to get the real length without any protocol check,
+	 * UDPLITE uses udph->len for another thing,
+	 * Use ip6h->payload_len + sizeof(*ip6h) ... , or just ipl.
+	 */
+
+	udph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*udph));
+	if (udph == NULL)
+		return 0;
+
+	ip6h = ipv6_hdr(skb);
+	ul = ntohs(udph->len);
+
+	udph->check = 0;
+
+	if (udplite) {
+		if (ul == 0)
+			skb->csum = csum_partial(udph, ipl - ihl, 0);
+
+		else if ((ul >= sizeof(*udph)) && (ul <= ipl - ihl))
+			skb->csum = csum_partial(udph, ul, 0);
+
+		else
+			goto ignore_obscure_skb;
+	} else {
+		if (ul != ipl - ihl)
+			goto ignore_obscure_skb;
+
+		skb->csum = csum_partial(udph, ul, 0);
+	}
+
+	udph->check = csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr, ul,
+				      udplite ? IPPROTO_UDPLITE : IPPROTO_UDP,
+				      skb->csum);
+
+	if (!udph->check)
+		udph->check = CSUM_MANGLED_0;
+
+	skb->ip_summed = CHECKSUM_NONE;
+
+ignore_obscure_skb:
+	return 1;
+}
+
+static int tcf_csum_ipv4(struct sk_buff *skb, u32 update_flags)
+{
+	const struct iphdr *iph;
+	int ntkoff;
+
+	ntkoff = skb_network_offset(skb);
+
+	if (!pskb_may_pull(skb, sizeof(*iph) + ntkoff))
+		goto fail;
+
+	iph = ip_hdr(skb);
+
+	switch (iph->frag_off & htons(IP_OFFSET) ? 0 : iph->protocol) {
+	case IPPROTO_ICMP:
+		if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
+			if (!tcf_csum_ipv4_icmp(skb, iph->ihl * 4,
+						ntohs(iph->tot_len)))
+				goto fail;
+		break;
+	case IPPROTO_IGMP:
+		if (update_flags & TCA_CSUM_UPDATE_FLAG_IGMP)
+			if (!tcf_csum_ipv4_igmp(skb, iph->ihl * 4,
+						ntohs(iph->tot_len)))
+				goto fail;
+		break;
+	case IPPROTO_TCP:
+		if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
+			if (!tcf_csum_ipv4_tcp(skb, iph->ihl * 4,
+					       ntohs(iph->tot_len)))
+				goto fail;
+		break;
+	case IPPROTO_UDP:
+		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
+			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
+					       ntohs(iph->tot_len), 0))
+				goto fail;
+		break;
+	case IPPROTO_UDPLITE:
+		if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
+			if (!tcf_csum_ipv4_udp(skb, iph->ihl * 4,
+					       ntohs(iph->tot_len), 1))
+				goto fail;
+		break;
+	}
+
+	if (update_flags & TCA_CSUM_UPDATE_FLAG_IPV4HDR) {
+		if (skb_cloned(skb) &&
+		    !skb_clone_writable(skb, sizeof(*iph) + ntkoff) &&
+		    pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
+			goto fail;
+
+		ip_send_check(ip_hdr(skb));
+	}
+
+	return 1;
+
+fail:
+	return 0;
+}
+
+static int tcf_csum_ipv6_hopopts(struct ipv6_opt_hdr *ip6xh,
+				 unsigned int ixhl, unsigned int *pl)
+{
+	int off, len, optlen;
+	unsigned char *xh = (void *)ip6xh;
+
+	off = sizeof(*ip6xh);
+	len = ixhl - off;
+
+	while (len > 1) {
+		switch (xh[off]) {
+		case IPV6_TLV_PAD1:
+			optlen = 1;
+			break;
+		case IPV6_TLV_JUMBO:
+			optlen = xh[off + 1] + 2;
+			if (optlen != 6 || len < 6 || (off & 3) != 2)
+				/* wrong jumbo option length/alignment */
+				return 0;
+			*pl = ntohl(*(__be32 *)(xh + off + 2));
+			goto done;
+		default:
+			optlen = xh[off + 1] + 2;
+			if (optlen > len)
+				/* ignore obscure options */
+				goto done;
+			break;
+		}
+		off += optlen;
+		len -= optlen;
+	}
+
+done:
+	return 1;
+}
+
+static int tcf_csum_ipv6(struct sk_buff *skb, u32 update_flags)
+{
+	struct ipv6hdr *ip6h;
+	struct ipv6_opt_hdr *ip6xh;
+	unsigned int hl, ixhl;
+	unsigned int pl;
+	int ntkoff;
+	u8 nexthdr;
+
+	ntkoff = skb_network_offset(skb);
+
+	hl = sizeof(*ip6h);
+
+	if (!pskb_may_pull(skb, hl + ntkoff))
+		goto fail;
+
+	ip6h = ipv6_hdr(skb);
+
+	pl = ntohs(ip6h->payload_len);
+	nexthdr = ip6h->nexthdr;
+
+	do {
+		switch (nexthdr) {
+		case NEXTHDR_FRAGMENT:
+			goto ignore_skb;
+		case NEXTHDR_ROUTING:
+		case NEXTHDR_HOP:
+		case NEXTHDR_DEST:
+			if (!pskb_may_pull(skb, hl + sizeof(*ip6xh) + ntkoff))
+				goto fail;
+			ip6xh = (void *)(skb_network_header(skb) + hl);
+			ixhl = ipv6_optlen(ip6xh);
+			if (!pskb_may_pull(skb, hl + ixhl + ntkoff))
+				goto fail;
+			ip6xh = (void *)(skb_network_header(skb) + hl);
+			if ((nexthdr == NEXTHDR_HOP) &&
+			    !(tcf_csum_ipv6_hopopts(ip6xh, ixhl, &pl)))
+				goto fail;
+			nexthdr = ip6xh->nexthdr;
+			hl += ixhl;
+			break;
+		case IPPROTO_ICMPV6:
+			if (update_flags & TCA_CSUM_UPDATE_FLAG_ICMP)
+				if (!tcf_csum_ipv6_icmp(skb,
+							hl, pl + sizeof(*ip6h)))
+					goto fail;
+			goto done;
+		case IPPROTO_TCP:
+			if (update_flags & TCA_CSUM_UPDATE_FLAG_TCP)
+				if (!tcf_csum_ipv6_tcp(skb,
+						       hl, pl + sizeof(*ip6h)))
+					goto fail;
+			goto done;
+		case IPPROTO_UDP:
+			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDP)
+				if (!tcf_csum_ipv6_udp(skb, hl,
+						       pl + sizeof(*ip6h), 0))
+					goto fail;
+			goto done;
+		case IPPROTO_UDPLITE:
+			if (update_flags & TCA_CSUM_UPDATE_FLAG_UDPLITE)
+				if (!tcf_csum_ipv6_udp(skb, hl,
+						       pl + sizeof(*ip6h), 1))
+					goto fail;
+			goto done;
+		default:
+			goto ignore_skb;
+		}
+	} while (pskb_may_pull(skb, hl + 1 + ntkoff));
+
+done:
+ignore_skb:
+	return 1;
+
+fail:
+	return 0;
+}
+
+static int tcf_csum(struct sk_buff *skb,
+		    const struct tc_action *a, struct tcf_result *res)
+{
+	struct tcf_csum *p = a->priv;
+	int action;
+	u32 update_flags;
+
+	spin_lock(&p->tcf_lock);
+	p->tcf_tm.lastuse = jiffies;
+	bstats_update(&p->tcf_bstats, skb);
+	action = p->tcf_action;
+	update_flags = p->update_flags;
+	spin_unlock(&p->tcf_lock);
+
+	if (unlikely(action == TC_ACT_SHOT))
+		goto drop;
+
+	switch (tc_skb_protocol(skb)) {
+	case cpu_to_be16(ETH_P_IP):
+		if (!tcf_csum_ipv4(skb, update_flags))
+			goto drop;
+		break;
+	case cpu_to_be16(ETH_P_IPV6):
+		if (!tcf_csum_ipv6(skb, update_flags))
+			goto drop;
+		break;
+	}
+
+	return action;
+
+drop:
+	spin_lock(&p->tcf_lock);
+	p->tcf_qstats.drops++;
+	spin_unlock(&p->tcf_lock);
+	return TC_ACT_SHOT;
+}
+
+static int tcf_csum_dump(struct sk_buff *skb,
+			 struct tc_action *a, int bind, int ref)
+{
+	unsigned char *b = skb_tail_pointer(skb);
+	struct tcf_csum *p = a->priv;
+	struct tc_csum opt = {
+		.update_flags = p->update_flags,
+		.index   = p->tcf_index,
+		.action  = p->tcf_action,
+		.refcnt  = p->tcf_refcnt - ref,
+		.bindcnt = p->tcf_bindcnt - bind,
+	};
+	struct tcf_t t;
+
+	if (nla_put(skb, TCA_CSUM_PARMS, sizeof(opt), &opt))
+		goto nla_put_failure;
+	t.install = jiffies_to_clock_t(jiffies - p->tcf_tm.install);
+	t.lastuse = jiffies_to_clock_t(jiffies - p->tcf_tm.lastuse);
+	t.expires = jiffies_to_clock_t(p->tcf_tm.expires);
+	if (nla_put(skb, TCA_CSUM_TM, sizeof(t), &t))
+		goto nla_put_failure;
+
+	return skb->len;
+
+nla_put_failure:
+	nlmsg_trim(skb, b);
+	return -1;
+}
+
+static struct tc_action_ops act_csum_ops = {
+	.kind		= "csum",
+	.type		= TCA_ACT_CSUM,
+	.owner		= THIS_MODULE,
+	.act		= tcf_csum,
+	.dump		= tcf_csum_dump,
+	.init		= tcf_csum_init,
+};
+
+MODULE_DESCRIPTION("Checksum updating actions");
+MODULE_LICENSE("GPL");
+
+static int __init csum_init_module(void)
+{
+	return tcf_register_action(&act_csum_ops, CSUM_TAB_MASK);
+}
+
+static void __exit csum_cleanup_module(void)
+{
+	tcf_unregister_action(&act_csum_ops);
+}
+
+module_init(csum_init_module);
+module_exit(csum_cleanup_module);