diff options
Diffstat (limited to 'net/sched/em_meta.c')
| -rw-r--r-- | net/sched/em_meta.c | 661 |
1 files changed, 661 insertions, 0 deletions
diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c new file mode 100644 index 00000000000..f1eeaf65cee --- /dev/null +++ b/net/sched/em_meta.c @@ -0,0 +1,661 @@ +/* + * net/sched/em_meta.c Metadata ematch + * + * 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: Thomas Graf <tgraf@suug.ch> + * + * ========================================================================== + * + * The metadata ematch compares two meta objects where each object + * represents either a meta value stored in the kernel or a static + * value provided by userspace. The objects are not provided by + * userspace itself but rather a definition providing the information + * to build them. Every object is of a certain type which must be + * equal to the object it is being compared to. + * + * The definition of a objects conists of the type (meta type), a + * identifier (meta id) and additional type specific information. + * The meta id is either TCF_META_TYPE_VALUE for values provided by + * userspace or a index to the meta operations table consisting of + * function pointers to type specific meta data collectors returning + * the value of the requested meta value. + * + * lvalue rvalue + * +-----------+ +-----------+ + * | type: INT | | type: INT | + * def | id: INDEV | | id: VALUE | + * | data: | | data: 3 | + * +-----------+ +-----------+ + * | | + * ---> meta_ops[INT][INDEV](...) | + * | | + * ----------- | + * V V + * +-----------+ +-----------+ + * | type: INT | | type: INT | + * obj | id: INDEV | | id: VALUE | + * | data: 2 |<--data got filled out | data: 3 | + * +-----------+ +-----------+ + * | | + * --------------> 2 equals 3 <-------------- + * + * This is a simplified schema, the complexity varies depending + * on the meta type. Obviously, the length of the data must also + * be provided for non-numeric types. + * + * Additionaly, type dependant modifiers such as shift operators + * or mask may be applied to extend the functionaliy. As of now, + * the variable length type supports shifting the byte string to + * the right, eating up any number of octets and thus supporting + * wildcard interface name comparisons such as "ppp%" matching + * ppp0..9. + * + * NOTE: Certain meta values depend on other subsystems and are + * only available if that subsytem is enabled in the kernel. + */ + +#include <linux/config.h> +#include <linux/module.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/string.h> +#include <linux/skbuff.h> +#include <linux/random.h> +#include <linux/tc_ematch/tc_em_meta.h> +#include <net/dst.h> +#include <net/route.h> +#include <net/pkt_cls.h> + +struct meta_obj +{ + unsigned long value; + unsigned int len; +}; + +struct meta_value +{ + struct tcf_meta_val hdr; + unsigned long val; + unsigned int len; +}; + +struct meta_match +{ + struct meta_value lvalue; + struct meta_value rvalue; +}; + +static inline int meta_id(struct meta_value *v) +{ + return TCF_META_ID(v->hdr.kind); +} + +static inline int meta_type(struct meta_value *v) +{ + return TCF_META_TYPE(v->hdr.kind); +} + +#define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \ + struct tcf_pkt_info *info, struct meta_value *v, \ + struct meta_obj *dst, int *err) + +/************************************************************************** + * System status & misc + **************************************************************************/ + +META_COLLECTOR(int_random) +{ + get_random_bytes(&dst->value, sizeof(dst->value)); +} + +static inline unsigned long fixed_loadavg(int load) +{ + int rnd_load = load + (FIXED_1/200); + int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT; + + return ((rnd_load >> FSHIFT) * 100) + rnd_frac; +} + +META_COLLECTOR(int_loadavg_0) +{ + dst->value = fixed_loadavg(avenrun[0]); +} + +META_COLLECTOR(int_loadavg_1) +{ + dst->value = fixed_loadavg(avenrun[1]); +} + +META_COLLECTOR(int_loadavg_2) +{ + dst->value = fixed_loadavg(avenrun[2]); +} + +/************************************************************************** + * Device names & indices + **************************************************************************/ + +static inline int int_dev(struct net_device *dev, struct meta_obj *dst) +{ + if (unlikely(dev == NULL)) + return -1; + + dst->value = dev->ifindex; + return 0; +} + +static inline int var_dev(struct net_device *dev, struct meta_obj *dst) +{ + if (unlikely(dev == NULL)) + return -1; + + dst->value = (unsigned long) dev->name; + dst->len = strlen(dev->name); + return 0; +} + +META_COLLECTOR(int_dev) +{ + *err = int_dev(skb->dev, dst); +} + +META_COLLECTOR(var_dev) +{ + *err = var_dev(skb->dev, dst); +} + +META_COLLECTOR(int_indev) +{ + *err = int_dev(skb->input_dev, dst); +} + +META_COLLECTOR(var_indev) +{ + *err = var_dev(skb->input_dev, dst); +} + +META_COLLECTOR(int_realdev) +{ + *err = int_dev(skb->real_dev, dst); +} + +META_COLLECTOR(var_realdev) +{ + *err = var_dev(skb->real_dev, dst); +} + +/************************************************************************** + * skb attributes + **************************************************************************/ + +META_COLLECTOR(int_priority) +{ + dst->value = skb->priority; +} + +META_COLLECTOR(int_protocol) +{ + /* Let userspace take care of the byte ordering */ + dst->value = skb->protocol; +} + +META_COLLECTOR(int_security) +{ + dst->value = skb->security; +} + +META_COLLECTOR(int_pkttype) +{ + dst->value = skb->pkt_type; +} + +META_COLLECTOR(int_pktlen) +{ + dst->value = skb->len; +} + +META_COLLECTOR(int_datalen) +{ + dst->value = skb->data_len; +} + +META_COLLECTOR(int_maclen) +{ + dst->value = skb->mac_len; +} + +/************************************************************************** + * Netfilter + **************************************************************************/ + +#ifdef CONFIG_NETFILTER +META_COLLECTOR(int_nfmark) +{ + dst->value = skb->nfmark; +} +#endif + +/************************************************************************** + * Traffic Control + **************************************************************************/ + +META_COLLECTOR(int_tcindex) +{ + dst->value = skb->tc_index; +} + +#ifdef CONFIG_NET_CLS_ACT +META_COLLECTOR(int_tcverd) +{ + dst->value = skb->tc_verd; +} + +META_COLLECTOR(int_tcclassid) +{ + dst->value = skb->tc_classid; +} +#endif + +/************************************************************************** + * Routing + **************************************************************************/ + +#ifdef CONFIG_NET_CLS_ROUTE +META_COLLECTOR(int_rtclassid) +{ + if (unlikely(skb->dst == NULL)) + *err = -1; + else + dst->value = skb->dst->tclassid; +} +#endif + +META_COLLECTOR(int_rtiif) +{ + if (unlikely(skb->dst == NULL)) + *err = -1; + else + dst->value = ((struct rtable*) skb->dst)->fl.iif; +} + +/************************************************************************** + * Meta value collectors assignment table + **************************************************************************/ + +struct meta_ops +{ + void (*get)(struct sk_buff *, struct tcf_pkt_info *, + struct meta_value *, struct meta_obj *, int *); +}; + +/* Meta value operations table listing all meta value collectors and + * assigns them to a type and meta id. */ +static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = { + [TCF_META_TYPE_VAR] = { + [TCF_META_ID_DEV] = { .get = meta_var_dev }, + [TCF_META_ID_INDEV] = { .get = meta_var_indev }, + [TCF_META_ID_REALDEV] = { .get = meta_var_realdev } + }, + [TCF_META_TYPE_INT] = { + [TCF_META_ID_RANDOM] = { .get = meta_int_random }, + [TCF_META_ID_LOADAVG_0] = { .get = meta_int_loadavg_0 }, + [TCF_META_ID_LOADAVG_1] = { .get = meta_int_loadavg_1 }, + [TCF_META_ID_LOADAVG_2] = { .get = meta_int_loadavg_2 }, + [TCF_META_ID_DEV] = { .get = meta_int_dev }, + [TCF_META_ID_INDEV] = { .get = meta_int_indev }, + [TCF_META_ID_REALDEV] = { .get = meta_int_realdev }, + [TCF_META_ID_PRIORITY] = { .get = meta_int_priority }, + [TCF_META_ID_PROTOCOL] = { .get = meta_int_protocol }, + [TCF_META_ID_SECURITY] = { .get = meta_int_security }, + [TCF_META_ID_PKTTYPE] = { .get = meta_int_pkttype }, + [TCF_META_ID_PKTLEN] = { .get = meta_int_pktlen }, + [TCF_META_ID_DATALEN] = { .get = meta_int_datalen }, + [TCF_META_ID_MACLEN] = { .get = meta_int_maclen }, +#ifdef CONFIG_NETFILTER + [TCF_META_ID_NFMARK] = { .get = meta_int_nfmark }, +#endif + [TCF_META_ID_TCINDEX] = { .get = meta_int_tcindex }, +#ifdef CONFIG_NET_CLS_ACT + [TCF_META_ID_TCVERDICT] = { .get = meta_int_tcverd }, + [TCF_META_ID_TCCLASSID] = { .get = meta_int_tcclassid }, +#endif +#ifdef CONFIG_NET_CLS_ROUTE + [TCF_META_ID_RTCLASSID] = { .get = meta_int_rtclassid }, +#endif + [TCF_META_ID_RTIIF] = { .get = meta_int_rtiif } + } +}; + +static inline struct meta_ops * meta_ops(struct meta_value *val) +{ + return &__meta_ops[meta_type(val)][meta_id(val)]; +} + +/************************************************************************** + * Type specific operations for TCF_META_TYPE_VAR + **************************************************************************/ + +static int meta_var_compare(struct meta_obj *a, struct meta_obj *b) +{ + int r = a->len - b->len; + + if (r == 0) + r = memcmp((void *) a->value, (void *) b->value, a->len); + + return r; +} + +static int meta_var_change(struct meta_value *dst, struct rtattr *rta) +{ + int len = RTA_PAYLOAD(rta); + + dst->val = (unsigned long) kmalloc(len, GFP_KERNEL); + if (dst->val == 0UL) + return -ENOMEM; + memcpy((void *) dst->val, RTA_DATA(rta), len); + dst->len = len; + return 0; +} + +static void meta_var_destroy(struct meta_value *v) +{ + if (v->val) + kfree((void *) v->val); +} + +static void meta_var_apply_extras(struct meta_value *v, + struct meta_obj *dst) +{ + int shift = v->hdr.shift; + + if (shift && shift < dst->len) + dst->len -= shift; +} + +static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv) +{ + if (v->val && v->len) + RTA_PUT(skb, tlv, v->len, (void *) v->val); + return 0; + +rtattr_failure: + return -1; +} + +/************************************************************************** + * Type specific operations for TCF_META_TYPE_INT + **************************************************************************/ + +static int meta_int_compare(struct meta_obj *a, struct meta_obj *b) +{ + /* Let gcc optimize it, the unlikely is not really based on + * some numbers but jump free code for mismatches seems + * more logical. */ + if (unlikely(a == b)) + return 0; + else if (a < b) + return -1; + else + return 1; +} + +static int meta_int_change(struct meta_value *dst, struct rtattr *rta) +{ + if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) { + dst->val = *(unsigned long *) RTA_DATA(rta); + dst->len = sizeof(unsigned long); + } else if (RTA_PAYLOAD(rta) == sizeof(u32)) { + dst->val = *(u32 *) RTA_DATA(rta); + dst->len = sizeof(u32); + } else + return -EINVAL; + + return 0; +} + +static void meta_int_apply_extras(struct meta_value *v, + struct meta_obj *dst) +{ + if (v->hdr.shift) + dst->value >>= v->hdr.shift; + + if (v->val) + dst->value &= v->val; +} + +static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv) +{ + if (v->len == sizeof(unsigned long)) + RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val); + else if (v->len == sizeof(u32)) { + u32 d = v->val; + RTA_PUT(skb, tlv, sizeof(d), &d); + } + + return 0; + +rtattr_failure: + return -1; +} + +/************************************************************************** + * Type specific operations table + **************************************************************************/ + +struct meta_type_ops +{ + void (*destroy)(struct meta_value *); + int (*compare)(struct meta_obj *, struct meta_obj *); + int (*change)(struct meta_value *, struct rtattr *); + void (*apply_extras)(struct meta_value *, struct meta_obj *); + int (*dump)(struct sk_buff *, struct meta_value *, int); +}; + +static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = { + [TCF_META_TYPE_VAR] = { + .destroy = meta_var_destroy, + .compare = meta_var_compare, + .change = meta_var_change, + .apply_extras = meta_var_apply_extras, + .dump = meta_var_dump + }, + [TCF_META_TYPE_INT] = { + .compare = meta_int_compare, + .change = meta_int_change, + .apply_extras = meta_int_apply_extras, + .dump = meta_int_dump + } +}; + +static inline struct meta_type_ops * meta_type_ops(struct meta_value *v) +{ + return &__meta_type_ops[meta_type(v)]; +} + +/************************************************************************** + * Core + **************************************************************************/ + +static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, + struct meta_value *v, struct meta_obj *dst) +{ + int err = 0; + + if (meta_id(v) == TCF_META_ID_VALUE) { + dst->value = v->val; + dst->len = v->len; + return 0; + } + + meta_ops(v)->get(skb, info, v, dst, &err); + if (err < 0) + return err; + + if (meta_type_ops(v)->apply_extras) + meta_type_ops(v)->apply_extras(v, dst); + + return 0; +} + +static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m, + struct tcf_pkt_info *info) +{ + int r; + struct meta_match *meta = (struct meta_match *) m->data; + struct meta_obj l_value, r_value; + + if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 || + meta_get(skb, info, &meta->rvalue, &r_value) < 0) + return 0; + + r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value); + + switch (meta->lvalue.hdr.op) { + case TCF_EM_OPND_EQ: + return !r; + case TCF_EM_OPND_LT: + return r < 0; + case TCF_EM_OPND_GT: + return r > 0; + } + + return 0; +} + +static inline void meta_delete(struct meta_match *meta) +{ + struct meta_type_ops *ops = meta_type_ops(&meta->lvalue); + + if (ops && ops->destroy) { + ops->destroy(&meta->lvalue); + ops->destroy(&meta->rvalue); + } + + kfree(meta); +} + +static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta) +{ + if (rta) { + if (RTA_PAYLOAD(rta) == 0) + return -EINVAL; + + return meta_type_ops(dst)->change(dst, rta); + } + + return 0; +} + +static inline int meta_is_supported(struct meta_value *val) +{ + return (!meta_id(val) || meta_ops(val)->get); +} + +static int em_meta_change(struct tcf_proto *tp, void *data, int len, + struct tcf_ematch *m) +{ + int err = -EINVAL; + struct rtattr *tb[TCA_EM_META_MAX]; + struct tcf_meta_hdr *hdr; + struct meta_match *meta = NULL; + + if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0) + goto errout; + + if (tb[TCA_EM_META_HDR-1] == NULL || + RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr)) + goto errout; + hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]); + + if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) || + TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX || + TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX || + TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX) + goto errout; + + meta = kmalloc(sizeof(*meta), GFP_KERNEL); + if (meta == NULL) + goto errout; + memset(meta, 0, sizeof(*meta)); + + memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left)); + memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right)); + + if (!meta_is_supported(&meta->lvalue) || + !meta_is_supported(&meta->rvalue)) { + err = -EOPNOTSUPP; + goto errout; + } + + if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 || + meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0) + goto errout; + + m->datalen = sizeof(*meta); + m->data = (unsigned long) meta; + + err = 0; +errout: + if (err && meta) + meta_delete(meta); + return err; +} + +static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m) +{ + if (m) + meta_delete((struct meta_match *) m->data); +} + +static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em) +{ + struct meta_match *meta = (struct meta_match *) em->data; + struct tcf_meta_hdr hdr; + struct meta_type_ops *ops; + + memset(&hdr, 0, sizeof(hdr)); + memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left)); + memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right)); + + RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr); + + ops = meta_type_ops(&meta->lvalue); + if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 || + ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0) + goto rtattr_failure; + + return 0; + +rtattr_failure: + return -1; +} + +static struct tcf_ematch_ops em_meta_ops = { + .kind = TCF_EM_META, + .change = em_meta_change, + .match = em_meta_match, + .destroy = em_meta_destroy, + .dump = em_meta_dump, + .owner = THIS_MODULE, + .link = LIST_HEAD_INIT(em_meta_ops.link) +}; + +static int __init init_em_meta(void) +{ + return tcf_em_register(&em_meta_ops); +} + +static void __exit exit_em_meta(void) +{ + tcf_em_unregister(&em_meta_ops); +} + +MODULE_LICENSE("GPL"); + +module_init(init_em_meta); +module_exit(exit_em_meta); |