--- /dev/null
+/*
+ * 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 struct tcf_common *tcf_csum_ht[CSUM_TAB_MASK + 1];
+static u32 csum_idx_gen;
+static DEFINE_RWLOCK(csum_lock);
+
+static struct tcf_hashinfo csum_hash_info = {
+ .htab = tcf_csum_ht,
+ .hmask = CSUM_TAB_MASK,
+ .lock = &csum_lock,
+};
+
+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 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_common *pc;
+ 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]);
+
+ pc = tcf_hash_check(parm->index, a, bind, &csum_hash_info);
+ if (!pc) {
+ pc = tcf_hash_create(parm->index, est, a, sizeof(*p), bind,
+ &csum_idx_gen, &csum_hash_info);
+ if (IS_ERR(pc))
+ return PTR_ERR(pc);
+ p = to_tcf_csum(pc);
+ ret = ACT_P_CREATED;
+ } else {
+ p = to_tcf_csum(pc);
+ if (!ovr) {
+ tcf_hash_release(pc, bind, &csum_hash_info);
+ return -EEXIST;
+ }
+ }
+
+ 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(pc, &csum_hash_info);
+
+ return ret;
+}
+
+static int tcf_csum_cleanup(struct tc_action *a, int bind)
+{
+ struct tcf_csum *p = a->priv;
+ return tcf_hash_release(&p->common, bind, &csum_hash_info);
+}
+
+/**
+ * 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, struct ipv6hdr *ip6h,
+ unsigned int ihl, unsigned int ipl)
+{
+ struct icmp6hdr *icmp6h;
+
+ icmp6h = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*icmp6h));
+ if (icmp6h == NULL)
+ return 0;
+
+ 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, struct iphdr *iph,
+ unsigned int ihl, unsigned int ipl)
+{
+ struct tcphdr *tcph;
+
+ tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
+ if (tcph == NULL)
+ return 0;
+
+ 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, struct ipv6hdr *ip6h,
+ unsigned int ihl, unsigned int ipl)
+{
+ struct tcphdr *tcph;
+
+ tcph = tcf_csum_skb_nextlayer(skb, ihl, ipl, sizeof(*tcph));
+ if (tcph == NULL)
+ return 0;
+
+ 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, struct iphdr *iph,
+ unsigned int ihl, unsigned int ipl, int udplite)
+{
+ struct udphdr *udph;
+ 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;
+
+ 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, struct ipv6hdr *ip6h,
+ unsigned int ihl, unsigned int ipl, int udplite)
+{
+ struct udphdr *udph;
+ 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;
+
+ 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)
+{
+ 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, 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, 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, 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(iph);
+ }
+
+ 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_PAD0:
+ 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;
+ 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, ip6h,
+ 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, ip6h,
+ 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, ip6h, 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, ip6h, 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,
+ 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;
+ p->tcf_bstats.bytes += qdisc_pkt_len(skb);
+ p->tcf_bstats.packets++;
+ action = p->tcf_action;
+ update_flags = p->update_flags;
+ spin_unlock(&p->tcf_lock);
+
+ if (unlikely(action == TC_ACT_SHOT))
+ goto drop;
+
+ switch (skb->protocol) {
+ 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;
+
+ NLA_PUT(skb, TCA_CSUM_PARMS, sizeof(opt), &opt);
+ 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);
+ NLA_PUT(skb, TCA_CSUM_TM, sizeof(t), &t);
+
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static struct tc_action_ops act_csum_ops = {
+ .kind = "csum",
+ .hinfo = &csum_hash_info,
+ .type = TCA_ACT_CSUM,
+ .capab = TCA_CAP_NONE,
+ .owner = THIS_MODULE,
+ .act = tcf_csum,
+ .dump = tcf_csum_dump,
+ .cleanup = tcf_csum_cleanup,
+ .lookup = tcf_hash_search,
+ .init = tcf_csum_init,
+ .walk = tcf_generic_walker
+};
+
+MODULE_DESCRIPTION("Checksum updating actions");
+MODULE_LICENSE("GPL");
+
+static int __init csum_init_module(void)
+{
+ return tcf_register_action(&act_csum_ops);
+}
+
+static void __exit csum_cleanup_module(void)
+{
+ tcf_unregister_action(&act_csum_ops);
+}
+
+module_init(csum_init_module);
+module_exit(csum_cleanup_module);
projects / mv-sheeva.git / blobdiff