/* net/sched/sch_dsmark.c - Differentiated Services field marker */ /* Written 1998-2000 by Werner Almesberger, EPFL ICA */ #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/types.h> #include <linux/string.h> #include <linux/errno.h> #include <linux/skbuff.h> #include <linux/rtnetlink.h> #include <linux/bitops.h> #include <net/pkt_sched.h> #include <net/dsfield.h> #include <net/inet_ecn.h> #include <asm/byteorder.h> /* * classid class marking * ------- ----- ------- * n/a 0 n/a * x:0 1 use entry [0] * ... ... ... * x:y y>0 y+1 use entry [y] * ... ... ... * x:indices-1 indices use entry [indices-1] * ... ... ... * x:y y+1 use entry [y & (indices-1)] * ... ... ... * 0xffff 0x10000 use entry [indices-1] */ #define NO_DEFAULT_INDEX (1 << 16) struct dsmark_qdisc_data { struct Qdisc *q; struct tcf_proto *filter_list; u8 *mask; /* "owns" the array */ u8 *value; u16 indices; u32 default_index; /* index range is 0...0xffff */ int set_tc_index; }; static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index) { return (index <= p->indices && index > 0); } /* ------------------------- Class/flow operations ------------------------- */ static int dsmark_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, struct Qdisc **old) { struct dsmark_qdisc_data *p = qdisc_priv(sch); pr_debug("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n", sch, p, new, old); if (new == NULL) { new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle); if (new == NULL) new = &noop_qdisc; } sch_tree_lock(sch); *old = p->q; p->q = new; qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); qdisc_reset(*old); sch_tree_unlock(sch); return 0; } static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg) { struct dsmark_qdisc_data *p = qdisc_priv(sch); return p->q; } static unsigned long dsmark_get(struct Qdisc *sch, u32 classid) { pr_debug("dsmark_get(sch %p,[qdisc %p],classid %x)\n", sch, qdisc_priv(sch), classid); return TC_H_MIN(classid) + 1; } static unsigned long dsmark_bind_filter(struct Qdisc *sch, unsigned long parent, u32 classid) { return dsmark_get(sch, classid); } static void dsmark_put(struct Qdisc *sch, unsigned long cl) { } static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = { [TCA_DSMARK_INDICES] = { .type = NLA_U16 }, [TCA_DSMARK_DEFAULT_INDEX] = { .type = NLA_U16 }, [TCA_DSMARK_SET_TC_INDEX] = { .type = NLA_FLAG }, [TCA_DSMARK_MASK] = { .type = NLA_U8 }, [TCA_DSMARK_VALUE] = { .type = NLA_U8 }, }; static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent, struct nlattr **tca, unsigned long *arg) { struct dsmark_qdisc_data *p = qdisc_priv(sch); struct nlattr *opt = tca[TCA_OPTIONS]; struct nlattr *tb[TCA_DSMARK_MAX + 1]; int err = -EINVAL; u8 mask = 0; pr_debug("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x)," "arg 0x%lx\n", sch, p, classid, parent, *arg); if (!dsmark_valid_index(p, *arg)) { err = -ENOENT; goto errout; } if (!opt) goto errout; err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy); if (err < 0) goto errout; if (tb[TCA_DSMARK_MASK]) mask = nla_get_u8(tb[TCA_DSMARK_MASK]); if (tb[TCA_DSMARK_VALUE]) p->value[*arg - 1] = nla_get_u8(tb[TCA_DSMARK_VALUE]); if (tb[TCA_DSMARK_MASK]) p->mask[*arg - 1] = mask; err = 0; errout: return err; } static int dsmark_delete(struct Qdisc *sch, unsigned long arg) { struct dsmark_qdisc_data *p = qdisc_priv(sch); if (!dsmark_valid_index(p, arg)) return -EINVAL; p->mask[arg - 1] = 0xff; p->value[arg - 1] = 0; return 0; } static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker) { struct dsmark_qdisc_data *p = qdisc_priv(sch); int i; pr_debug("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker); if (walker->stop) return; for (i = 0; i < p->indices; i++) { if (p->mask[i] == 0xff && !p->value[i]) goto ignore; if (walker->count >= walker->skip) { if (walker->fn(sch, i + 1, walker) < 0) { walker->stop = 1; break; } } ignore: walker->count++; } } static inline struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch, unsigned long cl) { struct dsmark_qdisc_data *p = qdisc_priv(sch); return &p->filter_list; } /* --------------------------- Qdisc operations ---------------------------- */ static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); int err; pr_debug("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p); if (p->set_tc_index) { switch (skb->protocol) { case htons(ETH_P_IP): if (skb_cow_head(skb, sizeof(struct iphdr))) goto drop; skb->tc_index = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK; break; case htons(ETH_P_IPV6): if (skb_cow_head(skb, sizeof(struct ipv6hdr))) goto drop; skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK; break; default: skb->tc_index = 0; break; } } if (TC_H_MAJ(skb->priority) == sch->handle) skb->tc_index = TC_H_MIN(skb->priority); else { struct tcf_result res; int result = tc_classify(skb, p->filter_list, &res); pr_debug("result %d class 0x%04x\n", result, res.classid); switch (result) { #ifdef CONFIG_NET_CLS_ACT case TC_ACT_QUEUED: case TC_ACT_STOLEN: kfree_skb(skb); return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; case TC_ACT_SHOT: goto drop; #endif case TC_ACT_OK: skb->tc_index = TC_H_MIN(res.classid); break; default: if (p->default_index != NO_DEFAULT_INDEX) skb->tc_index = p->default_index; break; } } err = qdisc_enqueue(skb, p->q); if (err != NET_XMIT_SUCCESS) { if (net_xmit_drop_count(err)) sch->qstats.drops++; return err; } sch->q.qlen++; return NET_XMIT_SUCCESS; drop: qdisc_drop(skb, sch); return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; } static struct sk_buff *dsmark_dequeue(struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); struct sk_buff *skb; u32 index; pr_debug("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p); skb = p->q->ops->dequeue(p->q); if (skb == NULL) return NULL; qdisc_bstats_update(sch, skb); sch->q.qlen--; index = skb->tc_index & (p->indices - 1); pr_debug("index %d->%d\n", skb->tc_index, index); switch (skb->protocol) { case htons(ETH_P_IP): ipv4_change_dsfield(ip_hdr(skb), p->mask[index], p->value[index]); break; case htons(ETH_P_IPV6): ipv6_change_dsfield(ipv6_hdr(skb), p->mask[index], p->value[index]); break; default: /* * Only complain if a change was actually attempted. * This way, we can send non-IP traffic through dsmark * and don't need yet another qdisc as a bypass. */ if (p->mask[index] != 0xff || p->value[index]) pr_warning("dsmark_dequeue: unsupported protocol %d\n", ntohs(skb->protocol)); break; } return skb; } static struct sk_buff *dsmark_peek(struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); pr_debug("dsmark_peek(sch %p,[qdisc %p])\n", sch, p); return p->q->ops->peek(p->q); } static unsigned int dsmark_drop(struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); unsigned int len; pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p); if (p->q->ops->drop == NULL) return 0; len = p->q->ops->drop(p->q); if (len) sch->q.qlen--; return len; } static int dsmark_init(struct Qdisc *sch, struct nlattr *opt) { struct dsmark_qdisc_data *p = qdisc_priv(sch); struct nlattr *tb[TCA_DSMARK_MAX + 1]; int err = -EINVAL; u32 default_index = NO_DEFAULT_INDEX; u16 indices; u8 *mask; pr_debug("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt); if (!opt) goto errout; err = nla_parse_nested(tb, TCA_DSMARK_MAX, opt, dsmark_policy); if (err < 0) goto errout; err = -EINVAL; indices = nla_get_u16(tb[TCA_DSMARK_INDICES]); if (hweight32(indices) != 1) goto errout; if (tb[TCA_DSMARK_DEFAULT_INDEX]) default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]); mask = kmalloc(indices * 2, GFP_KERNEL); if (mask == NULL) { err = -ENOMEM; goto errout; } p->mask = mask; memset(p->mask, 0xff, indices); p->value = p->mask + indices; memset(p->value, 0, indices); p->indices = indices; p->default_index = default_index; p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]); p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle); if (p->q == NULL) p->q = &noop_qdisc; pr_debug("dsmark_init: qdisc %p\n", p->q); err = 0; errout: return err; } static void dsmark_reset(struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); pr_debug("dsmark_reset(sch %p,[qdisc %p])\n", sch, p); qdisc_reset(p->q); sch->q.qlen = 0; } static void dsmark_destroy(struct Qdisc *sch) { struct dsmark_qdisc_data *p = qdisc_priv(sch); pr_debug("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p); tcf_destroy_chain(&p->filter_list); qdisc_destroy(p->q); kfree(p->mask); } static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl, struct sk_buff *skb, struct tcmsg *tcm) { struct dsmark_qdisc_data *p = qdisc_priv(sch); struct nlattr *opts = NULL; pr_debug("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl); if (!dsmark_valid_index(p, cl)) return -EINVAL; tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1); tcm->tcm_info = p->q->handle; opts = nla_nest_start(skb, TCA_OPTIONS); if (opts == NULL) goto nla_put_failure; if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mask[cl - 1]) || nla_put_u8(skb, TCA_DSMARK_VALUE, p->value[cl - 1])) goto nla_put_failure; return nla_nest_end(skb, opts); nla_put_failure: nla_nest_cancel(skb, opts); return -EMSGSIZE; } static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb) { struct dsmark_qdisc_data *p = qdisc_priv(sch); struct nlattr *opts = NULL; opts = nla_nest_start(skb, TCA_OPTIONS); if (opts == NULL) goto nla_put_failure; if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices)) goto nla_put_failure; if (p->default_index != NO_DEFAULT_INDEX && nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index)) goto nla_put_failure; if (p->set_tc_index && nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX)) goto nla_put_failure; return nla_nest_end(skb, opts); nla_put_failure: nla_nest_cancel(skb, opts); return -EMSGSIZE; } static const struct Qdisc_class_ops dsmark_class_ops = { .graft = dsmark_graft, .leaf = dsmark_leaf, .get = dsmark_get, .put = dsmark_put, .change = dsmark_change, .delete = dsmark_delete, .walk = dsmark_walk, .tcf_chain = dsmark_find_tcf, .bind_tcf = dsmark_bind_filter, .unbind_tcf = dsmark_put, .dump = dsmark_dump_class, }; static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = { .next = NULL, .cl_ops = &dsmark_class_ops, .id = "dsmark", .priv_size = sizeof(struct dsmark_qdisc_data), .enqueue = dsmark_enqueue, .dequeue = dsmark_dequeue, .peek = dsmark_peek, .drop = dsmark_drop, .init = dsmark_init, .reset = dsmark_reset, .destroy = dsmark_destroy, .change = NULL, .dump = dsmark_dump, .owner = THIS_MODULE, }; static int __init dsmark_module_init(void) { return register_qdisc(&dsmark_qdisc_ops); } static void __exit dsmark_module_exit(void) { unregister_qdisc(&dsmark_qdisc_ops); } module_init(dsmark_module_init) module_exit(dsmark_module_exit) MODULE_LICENSE("GPL");