--- /dev/null
+/*
+ * net/sched/cls_flow.c Generic flow classifier
+ *
+ * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/random.h>
+#include <linux/pkt_cls.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+
+#include <net/pkt_cls.h>
+#include <net/ip.h>
+#include <net/route.h>
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
+struct flow_head {
+ struct list_head filters;
+};
+
+struct flow_filter {
+ struct list_head list;
+ struct tcf_exts exts;
+ struct tcf_ematch_tree ematches;
+ u32 handle;
+
+ u32 nkeys;
+ u32 keymask;
+ u32 mode;
+ u32 mask;
+ u32 xor;
+ u32 rshift;
+ u32 addend;
+ u32 divisor;
+ u32 baseclass;
+};
+
+static u32 flow_hashrnd __read_mostly;
+static int flow_hashrnd_initted __read_mostly;
+
+static const struct tcf_ext_map flow_ext_map = {
+ .action = TCA_FLOW_ACT,
+ .police = TCA_FLOW_POLICE,
+};
+
+static inline u32 addr_fold(void *addr)
+{
+ unsigned long a = (unsigned long)addr;
+
+ return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
+}
+
+static u32 flow_get_src(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ return ntohl(ip_hdr(skb)->saddr);
+ case __constant_htons(ETH_P_IPV6):
+ return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
+ default:
+ return addr_fold(skb->sk);
+ }
+}
+
+static u32 flow_get_dst(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ return ntohl(ip_hdr(skb)->daddr);
+ case __constant_htons(ETH_P_IPV6):
+ return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
+ default:
+ return addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+ }
+}
+
+static u32 flow_get_proto(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ return ip_hdr(skb)->protocol;
+ case __constant_htons(ETH_P_IPV6):
+ return ipv6_hdr(skb)->nexthdr;
+ default:
+ return 0;
+ }
+}
+
+static int has_ports(u8 protocol)
+{
+ switch (protocol) {
+ case IPPROTO_TCP:
+ case IPPROTO_UDP:
+ case IPPROTO_UDPLITE:
+ case IPPROTO_SCTP:
+ case IPPROTO_DCCP:
+ case IPPROTO_ESP:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+static u32 flow_get_proto_src(const struct sk_buff *skb)
+{
+ u32 res = 0;
+
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP): {
+ struct iphdr *iph = ip_hdr(skb);
+
+ if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+ has_ports(iph->protocol))
+ res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4));
+ break;
+ }
+ case __constant_htons(ETH_P_IPV6): {
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+
+ if (has_ports(iph->nexthdr))
+ res = ntohs(*(__be16 *)&iph[1]);
+ break;
+ }
+ default:
+ res = addr_fold(skb->sk);
+ }
+
+ return res;
+}
+
+static u32 flow_get_proto_dst(const struct sk_buff *skb)
+{
+ u32 res = 0;
+
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP): {
+ struct iphdr *iph = ip_hdr(skb);
+
+ if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+ has_ports(iph->protocol))
+ res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2));
+ break;
+ }
+ case __constant_htons(ETH_P_IPV6): {
+ struct ipv6hdr *iph = ipv6_hdr(skb);
+
+ if (has_ports(iph->nexthdr))
+ res = ntohs(*(__be16 *)((void *)&iph[1] + 2));
+ break;
+ }
+ default:
+ res = addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+ }
+
+ return res;
+}
+
+static u32 flow_get_iif(const struct sk_buff *skb)
+{
+ return skb->iif;
+}
+
+static u32 flow_get_priority(const struct sk_buff *skb)
+{
+ return skb->priority;
+}
+
+static u32 flow_get_mark(const struct sk_buff *skb)
+{
+ return skb->mark;
+}
+
+static u32 flow_get_nfct(const struct sk_buff *skb)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+ return addr_fold(skb->nfct);
+#else
+ return 0;
+#endif
+}
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#define CTTUPLE(skb, member) \
+({ \
+ enum ip_conntrack_info ctinfo; \
+ struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \
+ if (ct == NULL) \
+ goto fallback; \
+ ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \
+})
+#else
+#define CTTUPLE(skb, member) \
+({ \
+ goto fallback; \
+ 0; \
+})
+#endif
+
+static u32 flow_get_nfct_src(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ return ntohl(CTTUPLE(skb, src.u3.ip));
+ case __constant_htons(ETH_P_IPV6):
+ return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
+ }
+fallback:
+ return flow_get_src(skb);
+}
+
+static u32 flow_get_nfct_dst(const struct sk_buff *skb)
+{
+ switch (skb->protocol) {
+ case __constant_htons(ETH_P_IP):
+ return ntohl(CTTUPLE(skb, dst.u3.ip));
+ case __constant_htons(ETH_P_IPV6):
+ return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
+ }
+fallback:
+ return flow_get_dst(skb);
+}
+
+static u32 flow_get_nfct_proto_src(const struct sk_buff *skb)
+{
+ return ntohs(CTTUPLE(skb, src.u.all));
+fallback:
+ return flow_get_proto_src(skb);
+}
+
+static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb)
+{
+ return ntohs(CTTUPLE(skb, dst.u.all));
+fallback:
+ return flow_get_proto_dst(skb);
+}
+
+static u32 flow_get_rtclassid(const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_CLS_ROUTE
+ if (skb->dst)
+ return skb->dst->tclassid;
+#endif
+ return 0;
+}
+
+static u32 flow_get_skuid(const struct sk_buff *skb)
+{
+ if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
+ return skb->sk->sk_socket->file->f_uid;
+ return 0;
+}
+
+static u32 flow_get_skgid(const struct sk_buff *skb)
+{
+ if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
+ return skb->sk->sk_socket->file->f_gid;
+ return 0;
+}
+
+static u32 flow_key_get(const struct sk_buff *skb, int key)
+{
+ switch (key) {
+ case FLOW_KEY_SRC:
+ return flow_get_src(skb);
+ case FLOW_KEY_DST:
+ return flow_get_dst(skb);
+ case FLOW_KEY_PROTO:
+ return flow_get_proto(skb);
+ case FLOW_KEY_PROTO_SRC:
+ return flow_get_proto_src(skb);
+ case FLOW_KEY_PROTO_DST:
+ return flow_get_proto_dst(skb);
+ case FLOW_KEY_IIF:
+ return flow_get_iif(skb);
+ case FLOW_KEY_PRIORITY:
+ return flow_get_priority(skb);
+ case FLOW_KEY_MARK:
+ return flow_get_mark(skb);
+ case FLOW_KEY_NFCT:
+ return flow_get_nfct(skb);
+ case FLOW_KEY_NFCT_SRC:
+ return flow_get_nfct_src(skb);
+ case FLOW_KEY_NFCT_DST:
+ return flow_get_nfct_dst(skb);
+ case FLOW_KEY_NFCT_PROTO_SRC:
+ return flow_get_nfct_proto_src(skb);
+ case FLOW_KEY_NFCT_PROTO_DST:
+ return flow_get_nfct_proto_dst(skb);
+ case FLOW_KEY_RTCLASSID:
+ return flow_get_rtclassid(skb);
+ case FLOW_KEY_SKUID:
+ return flow_get_skuid(skb);
+ case FLOW_KEY_SKGID:
+ return flow_get_skgid(skb);
+ default:
+ WARN_ON(1);
+ return 0;
+ }
+}
+
+static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ struct flow_head *head = tp->root;
+ struct flow_filter *f;
+ u32 keymask;
+ u32 classid;
+ unsigned int n, key;
+ int r;
+
+ list_for_each_entry(f, &head->filters, list) {
+ u32 keys[f->nkeys];
+
+ if (!tcf_em_tree_match(skb, &f->ematches, NULL))
+ continue;
+
+ keymask = f->keymask;
+
+ for (n = 0; n < f->nkeys; n++) {
+ key = ffs(keymask) - 1;
+ keymask &= ~(1 << key);
+ keys[n] = flow_key_get(skb, key);
+ }
+
+ if (f->mode == FLOW_MODE_HASH)
+ classid = jhash2(keys, f->nkeys, flow_hashrnd);
+ else {
+ classid = keys[0];
+ classid = (classid & f->mask) ^ f->xor;
+ classid = (classid >> f->rshift) + f->addend;
+ }
+
+ if (f->divisor)
+ classid %= f->divisor;
+
+ res->class = 0;
+ res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
+
+ r = tcf_exts_exec(skb, &f->exts, res);
+ if (r < 0)
+ continue;
+ return r;
+ }
+ return -1;
+}
+
+static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
+ [TCA_FLOW_KEYS] = { .type = NLA_U32 },
+ [TCA_FLOW_MODE] = { .type = NLA_U32 },
+ [TCA_FLOW_BASECLASS] = { .type = NLA_U32 },
+ [TCA_FLOW_RSHIFT] = { .type = NLA_U32 },
+ [TCA_FLOW_ADDEND] = { .type = NLA_U32 },
+ [TCA_FLOW_MASK] = { .type = NLA_U32 },
+ [TCA_FLOW_XOR] = { .type = NLA_U32 },
+ [TCA_FLOW_DIVISOR] = { .type = NLA_U32 },
+ [TCA_FLOW_ACT] = { .type = NLA_NESTED },
+ [TCA_FLOW_POLICE] = { .type = NLA_NESTED },
+ [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED },
+};
+
+static int flow_change(struct tcf_proto *tp, unsigned long base,
+ u32 handle, struct nlattr **tca,
+ unsigned long *arg)
+{
+ struct flow_head *head = tp->root;
+ struct flow_filter *f;
+ struct nlattr *opt = tca[TCA_OPTIONS];
+ struct nlattr *tb[TCA_FLOW_MAX + 1];
+ struct tcf_exts e;
+ struct tcf_ematch_tree t;
+ unsigned int nkeys = 0;
+ u32 baseclass = 0;
+ u32 keymask = 0;
+ u32 mode;
+ int err;
+
+ if (opt == NULL)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
+ if (err < 0)
+ return err;
+
+ if (tb[TCA_FLOW_BASECLASS]) {
+ baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
+ if (TC_H_MIN(baseclass) == 0)
+ return -EINVAL;
+ }
+
+ if (tb[TCA_FLOW_KEYS]) {
+ keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
+ if (fls(keymask) - 1 > FLOW_KEY_MAX)
+ return -EOPNOTSUPP;
+
+ nkeys = hweight32(keymask);
+ if (nkeys == 0)
+ return -EINVAL;
+ }
+
+ err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
+ if (err < 0)
+ return err;
+
+ err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
+ if (err < 0)
+ goto err1;
+
+ f = (struct flow_filter *)*arg;
+ if (f != NULL) {
+ err = -EINVAL;
+ if (f->handle != handle && handle)
+ goto err2;
+
+ mode = f->mode;
+ if (tb[TCA_FLOW_MODE])
+ mode = nla_get_u32(tb[TCA_FLOW_MODE]);
+ if (mode != FLOW_MODE_HASH && nkeys > 1)
+ goto err2;
+ } else {
+ err = -EINVAL;
+ if (!handle)
+ goto err2;
+ if (!tb[TCA_FLOW_KEYS])
+ goto err2;
+
+ mode = FLOW_MODE_MAP;
+ if (tb[TCA_FLOW_MODE])
+ mode = nla_get_u32(tb[TCA_FLOW_MODE]);
+ if (mode != FLOW_MODE_HASH && nkeys > 1)
+ goto err2;
+
+ if (TC_H_MAJ(baseclass) == 0)
+ baseclass = TC_H_MAKE(tp->q->handle, baseclass);
+ if (TC_H_MIN(baseclass) == 0)
+ baseclass = TC_H_MAKE(baseclass, 1);
+
+ err = -ENOBUFS;
+ f = kzalloc(sizeof(*f), GFP_KERNEL);
+ if (f == NULL)
+ goto err2;
+
+ f->handle = handle;
+ f->mask = ~0U;
+ }
+
+ tcf_exts_change(tp, &f->exts, &e);
+ tcf_em_tree_change(tp, &f->ematches, &t);
+
+ tcf_tree_lock(tp);
+
+ if (tb[TCA_FLOW_KEYS]) {
+ f->keymask = keymask;
+ f->nkeys = nkeys;
+ }
+
+ f->mode = mode;
+
+ if (tb[TCA_FLOW_MASK])
+ f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
+ if (tb[TCA_FLOW_XOR])
+ f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
+ if (tb[TCA_FLOW_RSHIFT])
+ f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
+ if (tb[TCA_FLOW_ADDEND])
+ f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
+
+ if (tb[TCA_FLOW_DIVISOR])
+ f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
+ if (baseclass)
+ f->baseclass = baseclass;
+
+ if (*arg == 0)
+ list_add_tail(&f->list, &head->filters);
+
+ tcf_tree_unlock(tp);
+
+ *arg = (unsigned long)f;
+ return 0;
+
+err2:
+ tcf_em_tree_destroy(tp, &t);
+err1:
+ tcf_exts_destroy(tp, &e);
+ return err;
+}
+
+static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
+{
+ tcf_exts_destroy(tp, &f->exts);
+ tcf_em_tree_destroy(tp, &f->ematches);
+ kfree(f);
+}
+
+static int flow_delete(struct tcf_proto *tp, unsigned long arg)
+{
+ struct flow_filter *f = (struct flow_filter *)arg;
+
+ tcf_tree_lock(tp);
+ list_del(&f->list);
+ tcf_tree_unlock(tp);
+ flow_destroy_filter(tp, f);
+ return 0;
+}
+
+static int flow_init(struct tcf_proto *tp)
+{
+ struct flow_head *head;
+
+ if (!flow_hashrnd_initted) {
+ get_random_bytes(&flow_hashrnd, 4);
+ flow_hashrnd_initted = 1;
+ }
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (head == NULL)
+ return -ENOBUFS;
+ INIT_LIST_HEAD(&head->filters);
+ tp->root = head;
+ return 0;
+}
+
+static void flow_destroy(struct tcf_proto *tp)
+{
+ struct flow_head *head = tp->root;
+ struct flow_filter *f, *next;
+
+ list_for_each_entry_safe(f, next, &head->filters, list) {
+ list_del(&f->list);
+ flow_destroy_filter(tp, f);
+ }
+ kfree(head);
+}
+
+static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
+{
+ struct flow_head *head = tp->root;
+ struct flow_filter *f;
+
+ list_for_each_entry(f, &head->filters, list)
+ if (f->handle == handle)
+ return (unsigned long)f;
+ return 0;
+}
+
+static void flow_put(struct tcf_proto *tp, unsigned long f)
+{
+ return;
+}
+
+static int flow_dump(struct tcf_proto *tp, unsigned long fh,
+ struct sk_buff *skb, struct tcmsg *t)
+{
+ struct flow_filter *f = (struct flow_filter *)fh;
+ struct nlattr *nest;
+
+ if (f == NULL)
+ return skb->len;
+
+ t->tcm_handle = f->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
+ NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
+
+ if (f->mask != ~0 || f->xor != 0) {
+ NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
+ NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
+ }
+ if (f->rshift)
+ NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
+ if (f->addend)
+ NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
+
+ if (f->divisor)
+ NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
+ if (f->baseclass)
+ NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
+
+ if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
+ goto nla_put_failure;
+
+ if (f->ematches.hdr.nmatches &&
+ tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+
+ if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nlmsg_trim(skb, nest);
+ return -1;
+}
+
+static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+{
+ struct flow_head *head = tp->root;
+ struct flow_filter *f;
+
+ list_for_each_entry(f, &head->filters, list) {
+ if (arg->count < arg->skip)
+ goto skip;
+ if (arg->fn(tp, (unsigned long)f, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+skip:
+ arg->count++;
+ }
+}
+
+static struct tcf_proto_ops cls_flow_ops __read_mostly = {
+ .kind = "flow",
+ .classify = flow_classify,
+ .init = flow_init,
+ .destroy = flow_destroy,
+ .change = flow_change,
+ .delete = flow_delete,
+ .get = flow_get,
+ .put = flow_put,
+ .dump = flow_dump,
+ .walk = flow_walk,
+ .owner = THIS_MODULE,
+};
+
+static int __init cls_flow_init(void)
+{
+ return register_tcf_proto_ops(&cls_flow_ops);
+}
+
+static void __exit cls_flow_exit(void)
+{
+ unregister_tcf_proto_ops(&cls_flow_ops);
+}
+
+module_init(cls_flow_init);
+module_exit(cls_flow_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("TC flow classifier");