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95 lines
1.9 KiB
95 lines
1.9 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* net/sched/em_cmp.c Simple packet data comparison ematch |
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* |
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* Authors: Thomas Graf <[email protected]> |
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*/ |
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/kernel.h> |
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#include <linux/skbuff.h> |
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#include <linux/tc_ematch/tc_em_cmp.h> |
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#include <asm/unaligned.h> |
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#include <net/pkt_cls.h> |
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static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp) |
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{ |
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return unlikely(cmp->flags & TCF_EM_CMP_TRANS); |
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} |
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static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em, |
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struct tcf_pkt_info *info) |
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{ |
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struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data; |
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unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer) + cmp->off; |
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u32 val = 0; |
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if (!tcf_valid_offset(skb, ptr, cmp->align)) |
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return 0; |
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switch (cmp->align) { |
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case TCF_EM_ALIGN_U8: |
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val = *ptr; |
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break; |
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case TCF_EM_ALIGN_U16: |
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val = get_unaligned_be16(ptr); |
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if (cmp_needs_transformation(cmp)) |
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val = be16_to_cpu(val); |
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break; |
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case TCF_EM_ALIGN_U32: |
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/* Worth checking boundaries? The branching seems |
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* to get worse. Visit again. |
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*/ |
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val = get_unaligned_be32(ptr); |
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if (cmp_needs_transformation(cmp)) |
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val = be32_to_cpu(val); |
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break; |
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default: |
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return 0; |
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} |
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if (cmp->mask) |
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val &= cmp->mask; |
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switch (cmp->opnd) { |
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case TCF_EM_OPND_EQ: |
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return val == cmp->val; |
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case TCF_EM_OPND_LT: |
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return val < cmp->val; |
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case TCF_EM_OPND_GT: |
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return val > cmp->val; |
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} |
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return 0; |
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} |
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static struct tcf_ematch_ops em_cmp_ops = { |
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.kind = TCF_EM_CMP, |
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.datalen = sizeof(struct tcf_em_cmp), |
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.match = em_cmp_match, |
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.owner = THIS_MODULE, |
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.link = LIST_HEAD_INIT(em_cmp_ops.link) |
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}; |
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static int __init init_em_cmp(void) |
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{ |
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return tcf_em_register(&em_cmp_ops); |
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} |
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static void __exit exit_em_cmp(void) |
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{ |
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tcf_em_unregister(&em_cmp_ops); |
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} |
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MODULE_LICENSE("GPL"); |
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module_init(init_em_cmp); |
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module_exit(exit_em_cmp); |
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MODULE_ALIAS_TCF_EMATCH(TCF_EM_CMP);
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