| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * net/sched/act_pedit.c Generic packet editor |
| * |
| * Authors: Jamal Hadi Salim (2002-4) |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/errno.h> |
| #include <linux/skbuff.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <net/netlink.h> |
| #include <net/pkt_sched.h> |
| #include <linux/tc_act/tc_pedit.h> |
| #include <net/tc_act/tc_pedit.h> |
| #include <uapi/linux/tc_act/tc_pedit.h> |
| #include <net/pkt_cls.h> |
| |
| static unsigned int pedit_net_id; |
| static struct tc_action_ops act_pedit_ops; |
| |
| static const struct nla_policy pedit_policy[TCA_PEDIT_MAX + 1] = { |
| [TCA_PEDIT_PARMS] = { .len = sizeof(struct tc_pedit) }, |
| [TCA_PEDIT_KEYS_EX] = { .type = NLA_NESTED }, |
| }; |
| |
| static const struct nla_policy pedit_key_ex_policy[TCA_PEDIT_KEY_EX_MAX + 1] = { |
| [TCA_PEDIT_KEY_EX_HTYPE] = { .type = NLA_U16 }, |
| [TCA_PEDIT_KEY_EX_CMD] = { .type = NLA_U16 }, |
| }; |
| |
| static struct tcf_pedit_key_ex *tcf_pedit_keys_ex_parse(struct nlattr *nla, |
| u8 n) |
| { |
| struct tcf_pedit_key_ex *keys_ex; |
| struct tcf_pedit_key_ex *k; |
| const struct nlattr *ka; |
| int err = -EINVAL; |
| int rem; |
| |
| if (!nla) |
| return NULL; |
| |
| keys_ex = kcalloc(n, sizeof(*k), GFP_KERNEL); |
| if (!keys_ex) |
| return ERR_PTR(-ENOMEM); |
| |
| k = keys_ex; |
| |
| nla_for_each_nested(ka, nla, rem) { |
| struct nlattr *tb[TCA_PEDIT_KEY_EX_MAX + 1]; |
| |
| if (!n) { |
| err = -EINVAL; |
| goto err_out; |
| } |
| n--; |
| |
| if (nla_type(ka) != TCA_PEDIT_KEY_EX) { |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| err = nla_parse_nested_deprecated(tb, TCA_PEDIT_KEY_EX_MAX, |
| ka, pedit_key_ex_policy, |
| NULL); |
| if (err) |
| goto err_out; |
| |
| if (!tb[TCA_PEDIT_KEY_EX_HTYPE] || |
| !tb[TCA_PEDIT_KEY_EX_CMD]) { |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| k->htype = nla_get_u16(tb[TCA_PEDIT_KEY_EX_HTYPE]); |
| k->cmd = nla_get_u16(tb[TCA_PEDIT_KEY_EX_CMD]); |
| |
| if (k->htype > TCA_PEDIT_HDR_TYPE_MAX || |
| k->cmd > TCA_PEDIT_CMD_MAX) { |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| k++; |
| } |
| |
| if (n) { |
| err = -EINVAL; |
| goto err_out; |
| } |
| |
| return keys_ex; |
| |
| err_out: |
| kfree(keys_ex); |
| return ERR_PTR(err); |
| } |
| |
| static int tcf_pedit_key_ex_dump(struct sk_buff *skb, |
| struct tcf_pedit_key_ex *keys_ex, int n) |
| { |
| struct nlattr *keys_start = nla_nest_start_noflag(skb, |
| TCA_PEDIT_KEYS_EX); |
| |
| if (!keys_start) |
| goto nla_failure; |
| for (; n > 0; n--) { |
| struct nlattr *key_start; |
| |
| key_start = nla_nest_start_noflag(skb, TCA_PEDIT_KEY_EX); |
| if (!key_start) |
| goto nla_failure; |
| |
| if (nla_put_u16(skb, TCA_PEDIT_KEY_EX_HTYPE, keys_ex->htype) || |
| nla_put_u16(skb, TCA_PEDIT_KEY_EX_CMD, keys_ex->cmd)) |
| goto nla_failure; |
| |
| nla_nest_end(skb, key_start); |
| |
| keys_ex++; |
| } |
| |
| nla_nest_end(skb, keys_start); |
| |
| return 0; |
| nla_failure: |
| nla_nest_cancel(skb, keys_start); |
| return -EINVAL; |
| } |
| |
| static int tcf_pedit_init(struct net *net, struct nlattr *nla, |
| struct nlattr *est, struct tc_action **a, |
| struct tcf_proto *tp, u32 flags, |
| struct netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, pedit_net_id); |
| bool bind = flags & TCA_ACT_FLAGS_BIND; |
| struct nlattr *tb[TCA_PEDIT_MAX + 1]; |
| struct tcf_chain *goto_ch = NULL; |
| struct tc_pedit_key *keys = NULL; |
| struct tcf_pedit_key_ex *keys_ex; |
| struct tc_pedit *parm; |
| struct nlattr *pattr; |
| struct tcf_pedit *p; |
| int ret = 0, err; |
| int i, ksize; |
| u32 index; |
| |
| if (!nla) { |
| NL_SET_ERR_MSG_MOD(extack, "Pedit requires attributes to be passed"); |
| return -EINVAL; |
| } |
| |
| err = nla_parse_nested_deprecated(tb, TCA_PEDIT_MAX, nla, |
| pedit_policy, NULL); |
| if (err < 0) |
| return err; |
| |
| pattr = tb[TCA_PEDIT_PARMS]; |
| if (!pattr) |
| pattr = tb[TCA_PEDIT_PARMS_EX]; |
| if (!pattr) { |
| NL_SET_ERR_MSG_MOD(extack, "Missing required TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute"); |
| return -EINVAL; |
| } |
| |
| parm = nla_data(pattr); |
| if (!parm->nkeys) { |
| NL_SET_ERR_MSG_MOD(extack, "Pedit requires keys to be passed"); |
| return -EINVAL; |
| } |
| ksize = parm->nkeys * sizeof(struct tc_pedit_key); |
| if (nla_len(pattr) < sizeof(*parm) + ksize) { |
| NL_SET_ERR_MSG_ATTR(extack, pattr, "Length of TCA_PEDIT_PARMS or TCA_PEDIT_PARMS_EX pedit attribute is invalid"); |
| return -EINVAL; |
| } |
| |
| keys_ex = tcf_pedit_keys_ex_parse(tb[TCA_PEDIT_KEYS_EX], parm->nkeys); |
| if (IS_ERR(keys_ex)) |
| return PTR_ERR(keys_ex); |
| |
| index = parm->index; |
| err = tcf_idr_check_alloc(tn, &index, a, bind); |
| if (!err) { |
| ret = tcf_idr_create(tn, index, est, a, |
| &act_pedit_ops, bind, false, 0); |
| if (ret) { |
| tcf_idr_cleanup(tn, index); |
| goto out_free; |
| } |
| ret = ACT_P_CREATED; |
| } else if (err > 0) { |
| if (bind) |
| goto out_free; |
| if (!(flags & TCA_ACT_FLAGS_REPLACE)) { |
| ret = -EEXIST; |
| goto out_release; |
| } |
| } else { |
| ret = err; |
| goto out_free; |
| } |
| |
| err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack); |
| if (err < 0) { |
| ret = err; |
| goto out_release; |
| } |
| p = to_pedit(*a); |
| spin_lock_bh(&p->tcf_lock); |
| |
| if (ret == ACT_P_CREATED || |
| (p->tcfp_nkeys && p->tcfp_nkeys != parm->nkeys)) { |
| keys = kmalloc(ksize, GFP_ATOMIC); |
| if (!keys) { |
| spin_unlock_bh(&p->tcf_lock); |
| ret = -ENOMEM; |
| goto put_chain; |
| } |
| kfree(p->tcfp_keys); |
| p->tcfp_keys = keys; |
| p->tcfp_nkeys = parm->nkeys; |
| } |
| memcpy(p->tcfp_keys, parm->keys, ksize); |
| p->tcfp_off_max_hint = 0; |
| for (i = 0; i < p->tcfp_nkeys; ++i) { |
| u32 cur = p->tcfp_keys[i].off; |
| |
| /* sanitize the shift value for any later use */ |
| p->tcfp_keys[i].shift = min_t(size_t, BITS_PER_TYPE(int) - 1, |
| p->tcfp_keys[i].shift); |
| |
| /* The AT option can read a single byte, we can bound the actual |
| * value with uchar max. |
| */ |
| cur += (0xff & p->tcfp_keys[i].offmask) >> p->tcfp_keys[i].shift; |
| |
| /* Each key touches 4 bytes starting from the computed offset */ |
| p->tcfp_off_max_hint = max(p->tcfp_off_max_hint, cur + 4); |
| } |
| |
| p->tcfp_flags = parm->flags; |
| goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch); |
| |
| kfree(p->tcfp_keys_ex); |
| p->tcfp_keys_ex = keys_ex; |
| |
| spin_unlock_bh(&p->tcf_lock); |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| return ret; |
| |
| put_chain: |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| out_release: |
| tcf_idr_release(*a, bind); |
| out_free: |
| kfree(keys_ex); |
| return ret; |
| |
| } |
| |
| static void tcf_pedit_cleanup(struct tc_action *a) |
| { |
| struct tcf_pedit *p = to_pedit(a); |
| struct tc_pedit_key *keys = p->tcfp_keys; |
| |
| kfree(keys); |
| kfree(p->tcfp_keys_ex); |
| } |
| |
| static bool offset_valid(struct sk_buff *skb, int offset) |
| { |
| if (offset > 0 && offset > skb->len) |
| return false; |
| |
| if (offset < 0 && -offset > skb_headroom(skb)) |
| return false; |
| |
| return true; |
| } |
| |
| static int pedit_skb_hdr_offset(struct sk_buff *skb, |
| enum pedit_header_type htype, int *hoffset) |
| { |
| int ret = -EINVAL; |
| |
| switch (htype) { |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH: |
| if (skb_mac_header_was_set(skb)) { |
| *hoffset = skb_mac_offset(skb); |
| ret = 0; |
| } |
| break; |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK: |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4: |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6: |
| *hoffset = skb_network_offset(skb); |
| ret = 0; |
| break; |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP: |
| case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP: |
| if (skb_transport_header_was_set(skb)) { |
| *hoffset = skb_transport_offset(skb); |
| ret = 0; |
| } |
| break; |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static int tcf_pedit_act(struct sk_buff *skb, const struct tc_action *a, |
| struct tcf_result *res) |
| { |
| struct tcf_pedit *p = to_pedit(a); |
| u32 max_offset; |
| int i; |
| |
| spin_lock(&p->tcf_lock); |
| |
| max_offset = (skb_transport_header_was_set(skb) ? |
| skb_transport_offset(skb) : |
| skb_network_offset(skb)) + |
| p->tcfp_off_max_hint; |
| if (skb_ensure_writable(skb, min(skb->len, max_offset))) |
| goto unlock; |
| |
| tcf_lastuse_update(&p->tcf_tm); |
| |
| if (p->tcfp_nkeys > 0) { |
| struct tc_pedit_key *tkey = p->tcfp_keys; |
| struct tcf_pedit_key_ex *tkey_ex = p->tcfp_keys_ex; |
| enum pedit_header_type htype = |
| TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK; |
| enum pedit_cmd cmd = TCA_PEDIT_KEY_EX_CMD_SET; |
| |
| for (i = p->tcfp_nkeys; i > 0; i--, tkey++) { |
| u32 *ptr, hdata; |
| int offset = tkey->off; |
| int hoffset; |
| u32 val; |
| int rc; |
| |
| if (tkey_ex) { |
| htype = tkey_ex->htype; |
| cmd = tkey_ex->cmd; |
| |
| tkey_ex++; |
| } |
| |
| rc = pedit_skb_hdr_offset(skb, htype, &hoffset); |
| if (rc) { |
| pr_info("tc action pedit bad header type specified (0x%x)\n", |
| htype); |
| goto bad; |
| } |
| |
| if (tkey->offmask) { |
| u8 *d, _d; |
| |
| if (!offset_valid(skb, hoffset + tkey->at)) { |
| pr_info("tc action pedit 'at' offset %d out of bounds\n", |
| hoffset + tkey->at); |
| goto bad; |
| } |
| d = skb_header_pointer(skb, hoffset + tkey->at, |
| sizeof(_d), &_d); |
| if (!d) |
| goto bad; |
| offset += (*d & tkey->offmask) >> tkey->shift; |
| } |
| |
| if (offset % 4) { |
| pr_info("tc action pedit offset must be on 32 bit boundaries\n"); |
| goto bad; |
| } |
| |
| if (!offset_valid(skb, hoffset + offset)) { |
| pr_info("tc action pedit offset %d out of bounds\n", |
| hoffset + offset); |
| goto bad; |
| } |
| |
| ptr = skb_header_pointer(skb, hoffset + offset, |
| sizeof(hdata), &hdata); |
| if (!ptr) |
| goto bad; |
| /* just do it, baby */ |
| switch (cmd) { |
| case TCA_PEDIT_KEY_EX_CMD_SET: |
| val = tkey->val; |
| break; |
| case TCA_PEDIT_KEY_EX_CMD_ADD: |
| val = (*ptr + tkey->val) & ~tkey->mask; |
| break; |
| default: |
| pr_info("tc action pedit bad command (%d)\n", |
| cmd); |
| goto bad; |
| } |
| |
| *ptr = ((*ptr & tkey->mask) ^ val); |
| if (ptr == &hdata) |
| skb_store_bits(skb, hoffset + offset, ptr, 4); |
| } |
| |
| goto done; |
| } else { |
| WARN(1, "pedit BUG: index %d\n", p->tcf_index); |
| } |
| |
| bad: |
| p->tcf_qstats.overlimits++; |
| done: |
| bstats_update(&p->tcf_bstats, skb); |
| unlock: |
| spin_unlock(&p->tcf_lock); |
| return p->tcf_action; |
| } |
| |
| static void tcf_pedit_stats_update(struct tc_action *a, u64 bytes, u64 packets, |
| u64 drops, u64 lastuse, bool hw) |
| { |
| struct tcf_pedit *d = to_pedit(a); |
| struct tcf_t *tm = &d->tcf_tm; |
| |
| tcf_action_update_stats(a, bytes, packets, drops, hw); |
| tm->lastuse = max_t(u64, tm->lastuse, lastuse); |
| } |
| |
| static int tcf_pedit_dump(struct sk_buff *skb, struct tc_action *a, |
| int bind, int ref) |
| { |
| unsigned char *b = skb_tail_pointer(skb); |
| struct tcf_pedit *p = to_pedit(a); |
| struct tc_pedit *opt; |
| struct tcf_t t; |
| int s; |
| |
| s = struct_size(opt, keys, p->tcfp_nkeys); |
| |
| /* netlink spinlocks held above us - must use ATOMIC */ |
| opt = kzalloc(s, GFP_ATOMIC); |
| if (unlikely(!opt)) |
| return -ENOBUFS; |
| |
| spin_lock_bh(&p->tcf_lock); |
| memcpy(opt->keys, p->tcfp_keys, flex_array_size(opt, keys, p->tcfp_nkeys)); |
| opt->index = p->tcf_index; |
| opt->nkeys = p->tcfp_nkeys; |
| opt->flags = p->tcfp_flags; |
| opt->action = p->tcf_action; |
| opt->refcnt = refcount_read(&p->tcf_refcnt) - ref; |
| opt->bindcnt = atomic_read(&p->tcf_bindcnt) - bind; |
| |
| if (p->tcfp_keys_ex) { |
| if (tcf_pedit_key_ex_dump(skb, |
| p->tcfp_keys_ex, |
| p->tcfp_nkeys)) |
| goto nla_put_failure; |
| |
| if (nla_put(skb, TCA_PEDIT_PARMS_EX, s, opt)) |
| goto nla_put_failure; |
| } else { |
| if (nla_put(skb, TCA_PEDIT_PARMS, s, opt)) |
| goto nla_put_failure; |
| } |
| |
| tcf_tm_dump(&t, &p->tcf_tm); |
| if (nla_put_64bit(skb, TCA_PEDIT_TM, sizeof(t), &t, TCA_PEDIT_PAD)) |
| goto nla_put_failure; |
| spin_unlock_bh(&p->tcf_lock); |
| |
| kfree(opt); |
| return skb->len; |
| |
| nla_put_failure: |
| spin_unlock_bh(&p->tcf_lock); |
| nlmsg_trim(skb, b); |
| kfree(opt); |
| return -1; |
| } |
| |
| static int tcf_pedit_walker(struct net *net, struct sk_buff *skb, |
| struct netlink_callback *cb, int type, |
| const struct tc_action_ops *ops, |
| struct netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, pedit_net_id); |
| |
| return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
| } |
| |
| static int tcf_pedit_search(struct net *net, struct tc_action **a, u32 index) |
| { |
| struct tc_action_net *tn = net_generic(net, pedit_net_id); |
| |
| return tcf_idr_search(tn, a, index); |
| } |
| |
| static struct tc_action_ops act_pedit_ops = { |
| .kind = "pedit", |
| .id = TCA_ID_PEDIT, |
| .owner = THIS_MODULE, |
| .act = tcf_pedit_act, |
| .stats_update = tcf_pedit_stats_update, |
| .dump = tcf_pedit_dump, |
| .cleanup = tcf_pedit_cleanup, |
| .init = tcf_pedit_init, |
| .walk = tcf_pedit_walker, |
| .lookup = tcf_pedit_search, |
| .size = sizeof(struct tcf_pedit), |
| }; |
| |
| static __net_init int pedit_init_net(struct net *net) |
| { |
| struct tc_action_net *tn = net_generic(net, pedit_net_id); |
| |
| return tc_action_net_init(net, tn, &act_pedit_ops); |
| } |
| |
| static void __net_exit pedit_exit_net(struct list_head *net_list) |
| { |
| tc_action_net_exit(net_list, pedit_net_id); |
| } |
| |
| static struct pernet_operations pedit_net_ops = { |
| .init = pedit_init_net, |
| .exit_batch = pedit_exit_net, |
| .id = &pedit_net_id, |
| .size = sizeof(struct tc_action_net), |
| }; |
| |
| MODULE_AUTHOR("Jamal Hadi Salim(2002-4)"); |
| MODULE_DESCRIPTION("Generic Packet Editor actions"); |
| MODULE_LICENSE("GPL"); |
| |
| static int __init pedit_init_module(void) |
| { |
| return tcf_register_action(&act_pedit_ops, &pedit_net_ops); |
| } |
| |
| static void __exit pedit_cleanup_module(void) |
| { |
| tcf_unregister_action(&act_pedit_ops, &pedit_net_ops); |
| } |
| |
| module_init(pedit_init_module); |
| module_exit(pedit_cleanup_module); |