cls_rsvp.h
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上传日期:2013-04-10
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文件大小:15k
- /*
- * net/sched/cls_rsvp.h Template file for RSVPv[46] classifiers.
- *
- * 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.
- *
- * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
- */
- /*
- Comparing to general packet classification problem,
- RSVP needs only sevaral relatively simple rules:
- * (dst, protocol) are always specified,
- so that we are able to hash them.
- * src may be exact, or may be wildcard, so that
- we can keep a hash table plus one wildcard entry.
- * source port (or flow label) is important only if src is given.
- IMPLEMENTATION.
- We use a two level hash table: The top level is keyed by
- destination address and protocol ID, every bucket contains a list
- of "rsvp sessions", identified by destination address, protocol and
- DPI(="Destination Port ID"): triple (key, mask, offset).
- Every bucket has a smaller hash table keyed by source address
- (cf. RSVP flowspec) and one wildcard entry for wildcard reservations.
- Every bucket is again a list of "RSVP flows", selected by
- source address and SPI(="Source Port ID" here rather than
- "security parameter index"): triple (key, mask, offset).
- NOTE 1. All the packets with IPv6 extension headers (but AH and ESP)
- and all fragmented packets go to the best-effort traffic class.
- NOTE 2. Two "port id"'s seems to be redundant, rfc2207 requires
- only one "Generalized Port Identifier". So that for classic
- ah, esp (and udp,tcp) both *pi should coincide or one of them
- should be wildcard.
- At first sight, this redundancy is just a waste of CPU
- resources. But DPI and SPI add the possibility to assign different
- priorities to GPIs. Look also at note 4 about tunnels below.
- NOTE 3. One complication is the case of tunneled packets.
- We implement it as following: if the first lookup
- matches a special session with "tunnelhdr" value not zero,
- flowid doesn't contain the true flow ID, but the tunnel ID (1...255).
- In this case, we pull tunnelhdr bytes and restart lookup
- with tunnel ID added to the list of keys. Simple and stupid 8)8)
- It's enough for PIMREG and IPIP.
- NOTE 4. Two GPIs make it possible to parse even GRE packets.
- F.e. DPI can select ETH_P_IP (and necessary flags to make
- tunnelhdr correct) in GRE protocol field and SPI matches
- GRE key. Is it not nice? 8)8)
- Well, as result, despite its simplicity, we get a pretty
- powerful classification engine. */
- #include <linux/config.h>
- struct rsvp_head
- {
- u32 tmap[256/32];
- u32 hgenerator;
- u8 tgenerator;
- struct rsvp_session *ht[256];
- };
- struct rsvp_session
- {
- struct rsvp_session *next;
- u32 dst[RSVP_DST_LEN];
- struct tc_rsvp_gpi dpi;
- u8 protocol;
- u8 tunnelid;
- /* 16 (src,sport) hash slots, and one wildcard source slot */
- struct rsvp_filter *ht[16+1];
- };
- struct rsvp_filter
- {
- struct rsvp_filter *next;
- u32 src[RSVP_DST_LEN];
- struct tc_rsvp_gpi spi;
- u8 tunnelhdr;
- struct tcf_result res;
- #ifdef CONFIG_NET_CLS_POLICE
- struct tcf_police *police;
- #endif
- u32 handle;
- struct rsvp_session *sess;
- };
- static __inline__ unsigned hash_dst(u32 *dst, u8 protocol, u8 tunnelid)
- {
- unsigned h = dst[RSVP_DST_LEN-1];
- h ^= h>>16;
- h ^= h>>8;
- return (h ^ protocol ^ tunnelid) & 0xFF;
- }
- static __inline__ unsigned hash_src(u32 *src)
- {
- unsigned h = src[RSVP_DST_LEN-1];
- h ^= h>>16;
- h ^= h>>8;
- h ^= h>>4;
- return h & 0xF;
- }
- #ifdef CONFIG_NET_CLS_POLICE
- #define RSVP_POLICE()
- if (f->police) {
- int pol_res = tcf_police(skb, f->police);
- if (pol_res < 0) continue;
- if (pol_res) return pol_res;
- }
- #else
- #define RSVP_POLICE()
- #endif
- static int rsvp_classify(struct sk_buff *skb, struct tcf_proto *tp,
- struct tcf_result *res)
- {
- struct rsvp_session **sht = ((struct rsvp_head*)tp->root)->ht;
- struct rsvp_session *s;
- struct rsvp_filter *f;
- unsigned h1, h2;
- u32 *dst, *src;
- u8 protocol;
- u8 tunnelid = 0;
- u8 *xprt;
- #if RSVP_DST_LEN == 4
- struct ipv6hdr *nhptr = skb->nh.ipv6h;
- #else
- struct iphdr *nhptr = skb->nh.iph;
- #endif
- #if !defined( __i386__) && !defined(__mc68000__)
- if ((unsigned long)nhptr & 3)
- return -1;
- #endif
- restart:
- #if RSVP_DST_LEN == 4
- src = &nhptr->saddr.s6_addr32[0];
- dst = &nhptr->daddr.s6_addr32[0];
- protocol = nhptr->nexthdr;
- xprt = ((u8*)nhptr) + sizeof(struct ipv6hdr);
- #else
- src = &nhptr->saddr;
- dst = &nhptr->daddr;
- protocol = nhptr->protocol;
- xprt = ((u8*)nhptr) + (nhptr->ihl<<2);
- if (nhptr->frag_off&__constant_htons(IP_MF|IP_OFFSET))
- return -1;
- #endif
- h1 = hash_dst(dst, protocol, tunnelid);
- h2 = hash_src(src);
- for (s = sht[h1]; s; s = s->next) {
- if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN-1] &&
- protocol == s->protocol &&
- !(s->dpi.mask & (*(u32*)(xprt+s->dpi.offset)^s->dpi.key))
- #if RSVP_DST_LEN == 4
- && dst[0] == s->dst[0]
- && dst[1] == s->dst[1]
- && dst[2] == s->dst[2]
- #endif
- && tunnelid == s->tunnelid) {
- for (f = s->ht[h2]; f; f = f->next) {
- if (src[RSVP_DST_LEN-1] == f->src[RSVP_DST_LEN-1] &&
- !(f->spi.mask & (*(u32*)(xprt+f->spi.offset)^f->spi.key))
- #if RSVP_DST_LEN == 4
- && src[0] == f->src[0]
- && src[1] == f->src[1]
- && src[2] == f->src[2]
- #endif
- ) {
- *res = f->res;
- RSVP_POLICE();
- matched:
- if (f->tunnelhdr == 0)
- return 0;
- tunnelid = f->res.classid;
- nhptr = (void*)(xprt + f->tunnelhdr - sizeof(*nhptr));
- goto restart;
- }
- }
- /* And wildcard bucket... */
- for (f = s->ht[16]; f; f = f->next) {
- *res = f->res;
- RSVP_POLICE();
- goto matched;
- }
- return -1;
- }
- }
- return -1;
- }
- static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle)
- {
- struct rsvp_session **sht = ((struct rsvp_head*)tp->root)->ht;
- struct rsvp_session *s;
- struct rsvp_filter *f;
- unsigned h1 = handle&0xFF;
- unsigned h2 = (handle>>8)&0xFF;
- if (h2 > 16)
- return 0;
- for (s = sht[h1]; s; s = s->next) {
- for (f = s->ht[h2]; f; f = f->next) {
- if (f->handle == handle)
- return (unsigned long)f;
- }
- }
- return 0;
- }
- static void rsvp_put(struct tcf_proto *tp, unsigned long f)
- {
- }
- static int rsvp_init(struct tcf_proto *tp)
- {
- struct rsvp_head *data;
- MOD_INC_USE_COUNT;
- data = kmalloc(sizeof(struct rsvp_head), GFP_KERNEL);
- if (data) {
- memset(data, 0, sizeof(struct rsvp_head));
- tp->root = data;
- return 0;
- }
- MOD_DEC_USE_COUNT;
- return -ENOBUFS;
- }
- static void rsvp_destroy(struct tcf_proto *tp)
- {
- struct rsvp_head *data = xchg(&tp->root, NULL);
- struct rsvp_session **sht;
- int h1, h2;
- if (data == NULL)
- return;
- sht = data->ht;
- for (h1=0; h1<256; h1++) {
- struct rsvp_session *s;
- while ((s = sht[h1]) != NULL) {
- sht[h1] = s->next;
- for (h2=0; h2<=16; h2++) {
- struct rsvp_filter *f;
- while ((f = s->ht[h2]) != NULL) {
- unsigned long cl;
- s->ht[h2] = f->next;
- if ((cl = __cls_set_class(&f->res.class, 0)) != 0)
- tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
- #ifdef CONFIG_NET_CLS_POLICE
- tcf_police_release(f->police);
- #endif
- kfree(f);
- }
- }
- kfree(s);
- }
- }
- kfree(data);
- MOD_DEC_USE_COUNT;
- }
- static int rsvp_delete(struct tcf_proto *tp, unsigned long arg)
- {
- struct rsvp_filter **fp, *f = (struct rsvp_filter*)arg;
- unsigned h = f->handle;
- struct rsvp_session **sp;
- struct rsvp_session *s = f->sess;
- int i;
- for (fp = &s->ht[(h>>8)&0xFF]; *fp; fp = &(*fp)->next) {
- if (*fp == f) {
- unsigned long cl;
- tcf_tree_lock(tp);
- *fp = f->next;
- tcf_tree_unlock(tp);
- if ((cl = cls_set_class(tp, &f->res.class, 0)) != 0)
- tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
- #ifdef CONFIG_NET_CLS_POLICE
- tcf_police_release(f->police);
- #endif
- kfree(f);
- /* Strip tree */
- for (i=0; i<=16; i++)
- if (s->ht[i])
- return 0;
- /* OK, session has no flows */
- for (sp = &((struct rsvp_head*)tp->root)->ht[h&0xFF];
- *sp; sp = &(*sp)->next) {
- if (*sp == s) {
- tcf_tree_lock(tp);
- *sp = s->next;
- tcf_tree_unlock(tp);
- kfree(s);
- return 0;
- }
- }
- return 0;
- }
- }
- return 0;
- }
- static unsigned gen_handle(struct tcf_proto *tp, unsigned salt)
- {
- struct rsvp_head *data = tp->root;
- int i = 0xFFFF;
- while (i-- > 0) {
- u32 h;
- if ((data->hgenerator += 0x10000) == 0)
- data->hgenerator = 0x10000;
- h = data->hgenerator|salt;
- if (rsvp_get(tp, h) == 0)
- return h;
- }
- return 0;
- }
- static int tunnel_bts(struct rsvp_head *data)
- {
- int n = data->tgenerator>>5;
- u32 b = 1<<(data->tgenerator&0x1F);
-
- if (data->tmap[n]&b)
- return 0;
- data->tmap[n] |= b;
- return 1;
- }
- static void tunnel_recycle(struct rsvp_head *data)
- {
- struct rsvp_session **sht = data->ht;
- u32 tmap[256/32];
- int h1, h2;
- memset(tmap, 0, sizeof(tmap));
- for (h1=0; h1<256; h1++) {
- struct rsvp_session *s;
- for (s = sht[h1]; s; s = s->next) {
- for (h2=0; h2<=16; h2++) {
- struct rsvp_filter *f;
- for (f = s->ht[h2]; f; f = f->next) {
- if (f->tunnelhdr == 0)
- continue;
- data->tgenerator = f->res.classid;
- tunnel_bts(data);
- }
- }
- }
- }
- memcpy(data->tmap, tmap, sizeof(tmap));
- }
- static u32 gen_tunnel(struct rsvp_head *data)
- {
- int i, k;
- for (k=0; k<2; k++) {
- for (i=255; i>0; i--) {
- if (++data->tgenerator == 0)
- data->tgenerator = 1;
- if (tunnel_bts(data))
- return data->tgenerator;
- }
- tunnel_recycle(data);
- }
- return 0;
- }
- static int rsvp_change(struct tcf_proto *tp, unsigned long base,
- u32 handle,
- struct rtattr **tca,
- unsigned long *arg)
- {
- struct rsvp_head *data = tp->root;
- struct rsvp_filter *f, **fp;
- struct rsvp_session *s, **sp;
- struct tc_rsvp_pinfo *pinfo = NULL;
- struct rtattr *opt = tca[TCA_OPTIONS-1];
- struct rtattr *tb[TCA_RSVP_MAX];
- unsigned h1, h2;
- u32 *dst;
- int err;
- if (opt == NULL)
- return handle ? -EINVAL : 0;
- if (rtattr_parse(tb, TCA_RSVP_MAX, RTA_DATA(opt), RTA_PAYLOAD(opt)) < 0)
- return -EINVAL;
- if ((f = (struct rsvp_filter*)*arg) != NULL) {
- /* Node exists: adjust only classid */
- if (f->handle != handle && handle)
- return -EINVAL;
- if (tb[TCA_RSVP_CLASSID-1]) {
- unsigned long cl;
- f->res.classid = *(u32*)RTA_DATA(tb[TCA_RSVP_CLASSID-1]);
- cl = cls_set_class(tp, &f->res.class, tp->q->ops->cl_ops->bind_tcf(tp->q, base, f->res.classid));
- if (cl)
- tp->q->ops->cl_ops->unbind_tcf(tp->q, cl);
- }
- #ifdef CONFIG_NET_CLS_POLICE
- if (tb[TCA_RSVP_POLICE-1]) {
- struct tcf_police *police = tcf_police_locate(tb[TCA_RSVP_POLICE-1], tca[TCA_RATE-1]);
- tcf_tree_lock(tp);
- police = xchg(&f->police, police);
- tcf_tree_unlock(tp);
- tcf_police_release(police);
- }
- #endif
- return 0;
- }
- /* Now more serious part... */
- if (handle)
- return -EINVAL;
- if (tb[TCA_RSVP_DST-1] == NULL)
- return -EINVAL;
- f = kmalloc(sizeof(struct rsvp_filter), GFP_KERNEL);
- if (f == NULL)
- return -ENOBUFS;
- memset(f, 0, sizeof(*f));
- h2 = 16;
- if (tb[TCA_RSVP_SRC-1]) {
- err = -EINVAL;
- if (RTA_PAYLOAD(tb[TCA_RSVP_SRC-1]) != sizeof(f->src))
- goto errout;
- memcpy(f->src, RTA_DATA(tb[TCA_RSVP_SRC-1]), sizeof(f->src));
- h2 = hash_src(f->src);
- }
- if (tb[TCA_RSVP_PINFO-1]) {
- err = -EINVAL;
- if (RTA_PAYLOAD(tb[TCA_RSVP_PINFO-1]) < sizeof(struct tc_rsvp_pinfo))
- goto errout;
- pinfo = RTA_DATA(tb[TCA_RSVP_PINFO-1]);
- f->spi = pinfo->spi;
- f->tunnelhdr = pinfo->tunnelhdr;
- }
- if (tb[TCA_RSVP_CLASSID-1]) {
- err = -EINVAL;
- if (RTA_PAYLOAD(tb[TCA_RSVP_CLASSID-1]) != 4)
- goto errout;
- f->res.classid = *(u32*)RTA_DATA(tb[TCA_RSVP_CLASSID-1]);
- }
- err = -EINVAL;
- if (RTA_PAYLOAD(tb[TCA_RSVP_DST-1]) != sizeof(f->src))
- goto errout;
- dst = RTA_DATA(tb[TCA_RSVP_DST-1]);
- h1 = hash_dst(dst, pinfo ? pinfo->protocol : 0, pinfo ? pinfo->tunnelid : 0);
- err = -ENOMEM;
- if ((f->handle = gen_handle(tp, h1 | (h2<<8))) == 0)
- goto errout;
- if (f->tunnelhdr) {
- err = -EINVAL;
- if (f->res.classid > 255)
- goto errout;
- err = -ENOMEM;
- if (f->res.classid == 0 &&
- (f->res.classid = gen_tunnel(data)) == 0)
- goto errout;
- }
- for (sp = &data->ht[h1]; (s=*sp) != NULL; sp = &s->next) {
- if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN-1] &&
- pinfo->protocol == s->protocol &&
- memcmp(&pinfo->dpi, &s->dpi, sizeof(s->dpi)) == 0
- #if RSVP_DST_LEN == 4
- && dst[0] == s->dst[0]
- && dst[1] == s->dst[1]
- && dst[2] == s->dst[2]
- #endif
- && pinfo->tunnelid == s->tunnelid) {
- insert:
- /* OK, we found appropriate session */
- fp = &s->ht[h2];
- f->sess = s;
- if (f->tunnelhdr == 0)
- cls_set_class(tp, &f->res.class, tp->q->ops->cl_ops->bind_tcf(tp->q, base, f->res.classid));
- #ifdef CONFIG_NET_CLS_POLICE
- if (tb[TCA_RSVP_POLICE-1])
- f->police = tcf_police_locate(tb[TCA_RSVP_POLICE-1], tca[TCA_RATE-1]);
- #endif
- for (fp = &s->ht[h2]; *fp; fp = &(*fp)->next)
- if (((*fp)->spi.mask&f->spi.mask) != f->spi.mask)
- break;
- f->next = *fp;
- wmb();
- *fp = f;
- *arg = (unsigned long)f;
- return 0;
- }
- }
- /* No session found. Create new one. */
- err = -ENOBUFS;
- s = kmalloc(sizeof(struct rsvp_session), GFP_KERNEL);
- if (s == NULL)
- goto errout;
- memset(s, 0, sizeof(*s));
- memcpy(s->dst, dst, sizeof(s->dst));
- s->dpi = pinfo->dpi;
- s->protocol = pinfo->protocol;
- s->tunnelid = pinfo->tunnelid;
- for (sp = &data->ht[h1]; *sp; sp = &(*sp)->next) {
- if (((*sp)->dpi.mask&s->dpi.mask) != s->dpi.mask)
- break;
- }
- s->next = *sp;
- wmb();
- *sp = s;
-
- goto insert;
- errout:
- if (f)
- kfree(f);
- return err;
- }
- static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg)
- {
- struct rsvp_head *head = tp->root;
- unsigned h, h1;
- if (arg->stop)
- return;
- for (h = 0; h < 256; h++) {
- struct rsvp_session *s;
- for (s = head->ht[h]; s; s = s->next) {
- for (h1 = 0; h1 <= 16; h1++) {
- struct rsvp_filter *f;
- for (f = s->ht[h1]; f; f = f->next) {
- if (arg->count < arg->skip) {
- arg->count++;
- continue;
- }
- if (arg->fn(tp, (unsigned long)f, arg) < 0) {
- arg->stop = 1;
- break;
- }
- arg->count++;
- }
- }
- }
- }
- }
- static int rsvp_dump(struct tcf_proto *tp, unsigned long fh,
- struct sk_buff *skb, struct tcmsg *t)
- {
- struct rsvp_filter *f = (struct rsvp_filter*)fh;
- struct rsvp_session *s;
- unsigned char *b = skb->tail;
- struct rtattr *rta;
- struct tc_rsvp_pinfo pinfo;
- if (f == NULL)
- return skb->len;
- s = f->sess;
- t->tcm_handle = f->handle;
- rta = (struct rtattr*)b;
- RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
- RTA_PUT(skb, TCA_RSVP_DST, sizeof(s->dst), &s->dst);
- pinfo.dpi = s->dpi;
- pinfo.spi = f->spi;
- pinfo.protocol = s->protocol;
- pinfo.tunnelid = s->tunnelid;
- pinfo.tunnelhdr = f->tunnelhdr;
- RTA_PUT(skb, TCA_RSVP_PINFO, sizeof(pinfo), &pinfo);
- if (f->res.classid)
- RTA_PUT(skb, TCA_RSVP_CLASSID, 4, &f->res.classid);
- if (((f->handle>>8)&0xFF) != 16)
- RTA_PUT(skb, TCA_RSVP_SRC, sizeof(f->src), f->src);
- #ifdef CONFIG_NET_CLS_POLICE
- if (f->police) {
- struct rtattr * p_rta = (struct rtattr*)skb->tail;
- RTA_PUT(skb, TCA_RSVP_POLICE, 0, NULL);
- if (tcf_police_dump(skb, f->police) < 0)
- goto rtattr_failure;
- p_rta->rta_len = skb->tail - (u8*)p_rta;
- }
- #endif
- rta->rta_len = skb->tail - b;
- #ifdef CONFIG_NET_CLS_POLICE
- if (f->police) {
- if (qdisc_copy_stats(skb, &f->police->stats))
- goto rtattr_failure;
- }
- #endif
- return skb->len;
- rtattr_failure:
- skb_trim(skb, b - skb->data);
- return -1;
- }
- struct tcf_proto_ops RSVP_OPS = {
- NULL,
- RSVP_ID,
- rsvp_classify,
- rsvp_init,
- rsvp_destroy,
- rsvp_get,
- rsvp_put,
- rsvp_change,
- rsvp_delete,
- rsvp_walk,
- rsvp_dump
- };
- #ifdef MODULE
- int init_module(void)
- {
- return register_tcf_proto_ops(&RSVP_OPS);
- }
- void cleanup_module(void)
- {
- unregister_tcf_proto_ops(&RSVP_OPS);
- }
- #endif