diff options
Diffstat (limited to 'net/sched/cls_rsvp.h')
-rw-r--r-- | net/sched/cls_rsvp.h | 667 |
1 files changed, 667 insertions, 0 deletions
diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h new file mode 100644 index 0000000..232fb91 --- /dev/null +++ b/net/sched/cls_rsvp.h @@ -0,0 +1,667 @@ +/* + * 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; + struct tcf_exts exts; + + 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; +} + +static struct tcf_ext_map rsvp_ext_map = { + .police = TCA_RSVP_POLICE, + .action = TCA_RSVP_ACT +}; + +#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, 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 + +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_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 = s->ht[16]; f; f = f->next) { + *res = f->res; + RSVP_APPLY_RESULT(); + 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; + + data = kmalloc(sizeof(struct rsvp_head), GFP_KERNEL); + if (data) { + memset(data, 0, sizeof(struct rsvp_head)); + tp->root = data; + return 0; + } + return -ENOBUFS; +} + +static inline void +rsvp_delete_filter(struct tcf_proto *tp, struct rsvp_filter *f) +{ + tcf_unbind_filter(tp, &f->res); + tcf_exts_destroy(tp, &f->exts); + kfree(f); +} + +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) { + s->ht[h2] = f->next; + rsvp_delete_filter(tp, f); + } + } + kfree(s); + } + } + kfree(data); +} + +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) { + tcf_tree_lock(tp); + *fp = f->next; + tcf_tree_unlock(tp); + rsvp_delete_filter(tp, 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]; + struct tcf_exts e; + unsigned h1, h2; + u32 *dst; + int err; + + if (opt == NULL) + return handle ? -EINVAL : 0; + + if (rtattr_parse_nested(tb, TCA_RSVP_MAX, opt) < 0) + return -EINVAL; + + err = tcf_exts_validate(tp, tb, tca[TCA_RATE-1], &e, &rsvp_ext_map); + if (err < 0) + return err; + + if ((f = (struct rsvp_filter*)*arg) != NULL) { + /* Node exists: adjust only classid */ + + if (f->handle != handle && handle) + goto errout2; + if (tb[TCA_RSVP_CLASSID-1]) { + f->res.classid = *(u32*)RTA_DATA(tb[TCA_RSVP_CLASSID-1]); + tcf_bind_filter(tp, &f->res, base); + } + + tcf_exts_change(tp, &f->exts, &e); + return 0; + } + + /* Now more serious part... */ + err = -EINVAL; + if (handle) + goto errout2; + if (tb[TCA_RSVP_DST-1] == NULL) + goto errout2; + + err = -ENOBUFS; + f = kmalloc(sizeof(struct rsvp_filter), GFP_KERNEL); + if (f == NULL) + goto errout2; + + 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 && 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); + + 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)); + + if (pinfo) { + 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); +errout2: + tcf_exts_destroy(tp, &e); + 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; + return; + } + 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); + + if (tcf_exts_dump(skb, &f->exts, &rsvp_ext_map) < 0) + goto rtattr_failure; + + rta->rta_len = skb->tail - b; + + if (tcf_exts_dump_stats(skb, &f->exts, &rsvp_ext_map) < 0) + goto rtattr_failure; + return skb->len; + +rtattr_failure: + skb_trim(skb, b - skb->data); + return -1; +} + +static struct tcf_proto_ops RSVP_OPS = { + .next = NULL, + .kind = RSVP_ID, + .classify = rsvp_classify, + .init = rsvp_init, + .destroy = rsvp_destroy, + .get = rsvp_get, + .put = rsvp_put, + .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) |