diff options
Diffstat (limited to 'kernel/net/sched/cls_rsvp.h')
| -rw-r--r-- | kernel/net/sched/cls_rsvp.h | 732 |
1 files changed, 732 insertions, 0 deletions
diff --git a/kernel/net/sched/cls_rsvp.h b/kernel/net/sched/cls_rsvp.h new file mode 100644 index 000000000..02fa82792 --- /dev/null +++ b/kernel/net/sched/cls_rsvp.h @@ -0,0 +1,732 @@ +/* + * 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. */ + + +struct rsvp_head { + u32 tmap[256/32]; + u32 hgenerator; + u8 tgenerator; + struct rsvp_session __rcu *ht[256]; + struct rcu_head rcu; +}; + +struct rsvp_session { + struct rsvp_session __rcu *next; + __be32 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 __rcu *ht[16 + 1]; + struct rcu_head rcu; +}; + + +struct rsvp_filter { + struct rsvp_filter __rcu *next; + __be32 src[RSVP_DST_LEN]; + struct tc_rsvp_gpi spi; + u8 tunnelhdr; + + struct tcf_result res; + struct tcf_exts exts; + + u32 handle; + struct rsvp_session *sess; + struct rcu_head rcu; +}; + +static inline unsigned int hash_dst(__be32 *dst, u8 protocol, u8 tunnelid) +{ + unsigned int h = (__force __u32)dst[RSVP_DST_LEN - 1]; + + h ^= h>>16; + h ^= h>>8; + return (h ^ protocol ^ tunnelid) & 0xFF; +} + +static inline unsigned int hash_src(__be32 *src) +{ + unsigned int h = (__force __u32)src[RSVP_DST_LEN-1]; + + h ^= h>>16; + h ^= h>>8; + h ^= h>>4; + return h & 0xF; +} + +#define RSVP_APPLY_RESULT() \ +{ \ + int r = tcf_exts_exec(skb, &f->exts, res); \ + if (r < 0) \ + continue; \ + else if (r > 0) \ + return r; \ +} + +static int rsvp_classify(struct sk_buff *skb, const struct tcf_proto *tp, + struct tcf_result *res) +{ + struct rsvp_head *head = rcu_dereference_bh(tp->root); + struct rsvp_session *s; + struct rsvp_filter *f; + unsigned int h1, h2; + __be32 *dst, *src; + u8 protocol; + u8 tunnelid = 0; + u8 *xprt; +#if RSVP_DST_LEN == 4 + struct ipv6hdr *nhptr; + + if (!pskb_network_may_pull(skb, sizeof(*nhptr))) + return -1; + nhptr = ipv6_hdr(skb); +#else + struct iphdr *nhptr; + + if (!pskb_network_may_pull(skb, sizeof(*nhptr))) + return -1; + nhptr = ip_hdr(skb); +#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 (ip_is_fragment(nhptr)) + return -1; +#endif + + h1 = hash_dst(dst, protocol, tunnelid); + h2 = hash_src(src); + + for (s = rcu_dereference_bh(head->ht[h1]); s; + s = rcu_dereference_bh(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 = rcu_dereference_bh(s->ht[h2]); f; + f = rcu_dereference_bh(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_APPLY_RESULT(); + +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 = rcu_dereference_bh(s->ht[16]); f; + f = rcu_dereference_bh(f->next)) { + *res = f->res; + RSVP_APPLY_RESULT(); + goto matched; + } + return -1; + } + } + return -1; +} + +static void rsvp_replace(struct tcf_proto *tp, struct rsvp_filter *n, u32 h) +{ + struct rsvp_head *head = rtnl_dereference(tp->root); + struct rsvp_session *s; + struct rsvp_filter __rcu **ins; + struct rsvp_filter *pins; + unsigned int h1 = h & 0xFF; + unsigned int h2 = (h >> 8) & 0xFF; + + for (s = rtnl_dereference(head->ht[h1]); s; + s = rtnl_dereference(s->next)) { + for (ins = &s->ht[h2], pins = rtnl_dereference(*ins); ; + ins = &pins->next, pins = rtnl_dereference(*ins)) { + if (pins->handle == h) { + RCU_INIT_POINTER(n->next, pins->next); + rcu_assign_pointer(*ins, n); + return; + } + } + } + + /* Something went wrong if we are trying to replace a non-existant + * node. Mind as well halt instead of silently failing. + */ + BUG_ON(1); +} + +static unsigned long rsvp_get(struct tcf_proto *tp, u32 handle) +{ + struct rsvp_head *head = rtnl_dereference(tp->root); + struct rsvp_session *s; + struct rsvp_filter *f; + unsigned int h1 = handle & 0xFF; + unsigned int h2 = (handle >> 8) & 0xFF; + + if (h2 > 16) + return 0; + + for (s = rtnl_dereference(head->ht[h1]); s; + s = rtnl_dereference(s->next)) { + for (f = rtnl_dereference(s->ht[h2]); f; + f = rtnl_dereference(f->next)) { + if (f->handle == handle) + return (unsigned long)f; + } + } + return 0; +} + +static int rsvp_init(struct tcf_proto *tp) +{ + struct rsvp_head *data; + + data = kzalloc(sizeof(struct rsvp_head), GFP_KERNEL); + if (data) { + rcu_assign_pointer(tp->root, data); + return 0; + } + return -ENOBUFS; +} + +static void +rsvp_delete_filter(struct tcf_proto *tp, struct rsvp_filter *f) +{ + tcf_unbind_filter(tp, &f->res); + tcf_exts_destroy(&f->exts); + kfree_rcu(f, rcu); +} + +static bool rsvp_destroy(struct tcf_proto *tp, bool force) +{ + struct rsvp_head *data = rtnl_dereference(tp->root); + int h1, h2; + + if (data == NULL) + return true; + + if (!force) { + for (h1 = 0; h1 < 256; h1++) { + if (rcu_access_pointer(data->ht[h1])) + return false; + } + } + + RCU_INIT_POINTER(tp->root, NULL); + + for (h1 = 0; h1 < 256; h1++) { + struct rsvp_session *s; + + while ((s = rtnl_dereference(data->ht[h1])) != NULL) { + RCU_INIT_POINTER(data->ht[h1], s->next); + + for (h2 = 0; h2 <= 16; h2++) { + struct rsvp_filter *f; + + while ((f = rtnl_dereference(s->ht[h2])) != NULL) { + rcu_assign_pointer(s->ht[h2], f->next); + rsvp_delete_filter(tp, f); + } + } + kfree_rcu(s, rcu); + } + } + kfree_rcu(data, rcu); + return true; +} + +static int rsvp_delete(struct tcf_proto *tp, unsigned long arg) +{ + struct rsvp_head *head = rtnl_dereference(tp->root); + struct rsvp_filter *nfp, *f = (struct rsvp_filter *)arg; + struct rsvp_filter __rcu **fp; + unsigned int h = f->handle; + struct rsvp_session __rcu **sp; + struct rsvp_session *nsp, *s = f->sess; + int i; + + fp = &s->ht[(h >> 8) & 0xFF]; + for (nfp = rtnl_dereference(*fp); nfp; + fp = &nfp->next, nfp = rtnl_dereference(*fp)) { + if (nfp == f) { + RCU_INIT_POINTER(*fp, f->next); + rsvp_delete_filter(tp, f); + + /* Strip tree */ + + for (i = 0; i <= 16; i++) + if (s->ht[i]) + return 0; + + /* OK, session has no flows */ + sp = &head->ht[h & 0xFF]; + for (nsp = rtnl_dereference(*sp); nsp; + sp = &nsp->next, nsp = rtnl_dereference(*sp)) { + if (nsp == s) { + RCU_INIT_POINTER(*sp, s->next); + kfree_rcu(s, rcu); + return 0; + } + } + + return 0; + } + } + return 0; +} + +static unsigned int gen_handle(struct tcf_proto *tp, unsigned salt) +{ + struct rsvp_head *data = rtnl_dereference(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 __rcu **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 = rtnl_dereference(sht[h1]); s; + s = rtnl_dereference(s->next)) { + for (h2 = 0; h2 <= 16; h2++) { + struct rsvp_filter *f; + + for (f = rtnl_dereference(s->ht[h2]); f; + f = rtnl_dereference(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 const struct nla_policy rsvp_policy[TCA_RSVP_MAX + 1] = { + [TCA_RSVP_CLASSID] = { .type = NLA_U32 }, + [TCA_RSVP_DST] = { .type = NLA_BINARY, + .len = RSVP_DST_LEN * sizeof(u32) }, + [TCA_RSVP_SRC] = { .type = NLA_BINARY, + .len = RSVP_DST_LEN * sizeof(u32) }, + [TCA_RSVP_PINFO] = { .len = sizeof(struct tc_rsvp_pinfo) }, +}; + +static int rsvp_change(struct net *net, struct sk_buff *in_skb, + struct tcf_proto *tp, unsigned long base, + u32 handle, + struct nlattr **tca, + unsigned long *arg, bool ovr) +{ + struct rsvp_head *data = rtnl_dereference(tp->root); + struct rsvp_filter *f, *nfp; + struct rsvp_filter __rcu **fp; + struct rsvp_session *nsp, *s; + struct rsvp_session __rcu **sp; + struct tc_rsvp_pinfo *pinfo = NULL; + struct nlattr *opt = tca[TCA_OPTIONS]; + struct nlattr *tb[TCA_RSVP_MAX + 1]; + struct tcf_exts e; + unsigned int h1, h2; + __be32 *dst; + int err; + + if (opt == NULL) + return handle ? -EINVAL : 0; + + err = nla_parse_nested(tb, TCA_RSVP_MAX, opt, rsvp_policy); + if (err < 0) + return err; + + tcf_exts_init(&e, TCA_RSVP_ACT, TCA_RSVP_POLICE); + err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr); + if (err < 0) + return err; + + f = (struct rsvp_filter *)*arg; + if (f) { + /* Node exists: adjust only classid */ + struct rsvp_filter *n; + + if (f->handle != handle && handle) + goto errout2; + + n = kmemdup(f, sizeof(*f), GFP_KERNEL); + if (!n) { + err = -ENOMEM; + goto errout2; + } + + tcf_exts_init(&n->exts, TCA_RSVP_ACT, TCA_RSVP_POLICE); + + if (tb[TCA_RSVP_CLASSID]) { + n->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]); + tcf_bind_filter(tp, &n->res, base); + } + + tcf_exts_change(tp, &n->exts, &e); + rsvp_replace(tp, n, handle); + return 0; + } + + /* Now more serious part... */ + err = -EINVAL; + if (handle) + goto errout2; + if (tb[TCA_RSVP_DST] == NULL) + goto errout2; + + err = -ENOBUFS; + f = kzalloc(sizeof(struct rsvp_filter), GFP_KERNEL); + if (f == NULL) + goto errout2; + + tcf_exts_init(&f->exts, TCA_RSVP_ACT, TCA_RSVP_POLICE); + h2 = 16; + if (tb[TCA_RSVP_SRC]) { + memcpy(f->src, nla_data(tb[TCA_RSVP_SRC]), sizeof(f->src)); + h2 = hash_src(f->src); + } + if (tb[TCA_RSVP_PINFO]) { + pinfo = nla_data(tb[TCA_RSVP_PINFO]); + f->spi = pinfo->spi; + f->tunnelhdr = pinfo->tunnelhdr; + } + if (tb[TCA_RSVP_CLASSID]) + f->res.classid = nla_get_u32(tb[TCA_RSVP_CLASSID]); + + dst = nla_data(tb[TCA_RSVP_DST]); + 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 = rtnl_dereference(*sp)) != NULL; + sp = &s->next) { + if (dst[RSVP_DST_LEN-1] == s->dst[RSVP_DST_LEN-1] && + pinfo && 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) + tcf_bind_filter(tp, &f->res, base); + + tcf_exts_change(tp, &f->exts, &e); + + fp = &s->ht[h2]; + for (nfp = rtnl_dereference(*fp); nfp; + fp = &nfp->next, nfp = rtnl_dereference(*fp)) { + __u32 mask = nfp->spi.mask & f->spi.mask; + + if (mask != f->spi.mask) + break; + } + RCU_INIT_POINTER(f->next, nfp); + rcu_assign_pointer(*fp, f); + + *arg = (unsigned long)f; + return 0; + } + } + + /* No session found. Create new one. */ + + err = -ENOBUFS; + s = kzalloc(sizeof(struct rsvp_session), GFP_KERNEL); + if (s == NULL) + goto errout; + memcpy(s->dst, dst, sizeof(s->dst)); + + if (pinfo) { + s->dpi = pinfo->dpi; + s->protocol = pinfo->protocol; + s->tunnelid = pinfo->tunnelid; + } + sp = &data->ht[h1]; + for (nsp = rtnl_dereference(*sp); nsp; + sp = &nsp->next, nsp = rtnl_dereference(*sp)) { + if ((nsp->dpi.mask & s->dpi.mask) != s->dpi.mask) + break; + } + RCU_INIT_POINTER(s->next, nsp); + rcu_assign_pointer(*sp, s); + + goto insert; + +errout: + kfree(f); +errout2: + tcf_exts_destroy(&e); + return err; +} + +static void rsvp_walk(struct tcf_proto *tp, struct tcf_walker *arg) +{ + struct rsvp_head *head = rtnl_dereference(tp->root); + unsigned int h, h1; + + if (arg->stop) + return; + + for (h = 0; h < 256; h++) { + struct rsvp_session *s; + + for (s = rtnl_dereference(head->ht[h]); s; + s = rtnl_dereference(s->next)) { + for (h1 = 0; h1 <= 16; h1++) { + struct rsvp_filter *f; + + for (f = rtnl_dereference(s->ht[h1]); f; + f = rtnl_dereference(f->next)) { + if (arg->count < arg->skip) { + arg->count++; + continue; + } + if (arg->fn(tp, (unsigned long)f, arg) < 0) { + arg->stop = 1; + return; + } + arg->count++; + } + } + } + } +} + +static int rsvp_dump(struct net *net, 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; + struct nlattr *nest; + struct tc_rsvp_pinfo pinfo; + + if (f == NULL) + return skb->len; + s = f->sess; + + t->tcm_handle = f->handle; + + nest = nla_nest_start(skb, TCA_OPTIONS); + if (nest == NULL) + goto nla_put_failure; + + if (nla_put(skb, TCA_RSVP_DST, sizeof(s->dst), &s->dst)) + goto nla_put_failure; + pinfo.dpi = s->dpi; + pinfo.spi = f->spi; + pinfo.protocol = s->protocol; + pinfo.tunnelid = s->tunnelid; + pinfo.tunnelhdr = f->tunnelhdr; + pinfo.pad = 0; + if (nla_put(skb, TCA_RSVP_PINFO, sizeof(pinfo), &pinfo)) + goto nla_put_failure; + if (f->res.classid && + nla_put_u32(skb, TCA_RSVP_CLASSID, f->res.classid)) + goto nla_put_failure; + if (((f->handle >> 8) & 0xFF) != 16 && + nla_put(skb, TCA_RSVP_SRC, sizeof(f->src), f->src)) + goto nla_put_failure; + + if (tcf_exts_dump(skb, &f->exts) < 0) + goto nla_put_failure; + + nla_nest_end(skb, nest); + + if (tcf_exts_dump_stats(skb, &f->exts) < 0) + goto nla_put_failure; + return skb->len; + +nla_put_failure: + nla_nest_cancel(skb, nest); + return -1; +} + +static struct tcf_proto_ops RSVP_OPS __read_mostly = { + .kind = RSVP_ID, + .classify = rsvp_classify, + .init = rsvp_init, + .destroy = rsvp_destroy, + .get = rsvp_get, + .change = rsvp_change, + .delete = rsvp_delete, + .walk = rsvp_walk, + .dump = rsvp_dump, + .owner = THIS_MODULE, +}; + +static int __init init_rsvp(void) +{ + return register_tcf_proto_ops(&RSVP_OPS); +} + +static void __exit exit_rsvp(void) +{ + unregister_tcf_proto_ops(&RSVP_OPS); +} + +module_init(init_rsvp) +module_exit(exit_rsvp) |