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![Andrii Nakryiko](/assets/img/avatar_default.png)
Free struct strset itself, not just its internal parts.
Fixes: 90d76d3ece
("libbpf: Extract internal set-of-strings datastructure APIs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20211001185910.86492-1-andrii@kernel.org
177 lines
4.4 KiB
C
177 lines
4.4 KiB
C
// SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause)
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/* Copyright (c) 2021 Facebook */
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#include <stdint.h>
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#include <stdlib.h>
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#include <stdio.h>
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#include <errno.h>
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#include <linux/err.h>
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#include "hashmap.h"
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#include "libbpf_internal.h"
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#include "strset.h"
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struct strset {
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void *strs_data;
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size_t strs_data_len;
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size_t strs_data_cap;
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size_t strs_data_max_len;
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/* lookup index for each unique string in strings set */
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struct hashmap *strs_hash;
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};
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static size_t strset_hash_fn(const void *key, void *ctx)
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{
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const struct strset *s = ctx;
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const char *str = s->strs_data + (long)key;
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return str_hash(str);
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}
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static bool strset_equal_fn(const void *key1, const void *key2, void *ctx)
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{
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const struct strset *s = ctx;
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const char *str1 = s->strs_data + (long)key1;
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const char *str2 = s->strs_data + (long)key2;
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return strcmp(str1, str2) == 0;
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}
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struct strset *strset__new(size_t max_data_sz, const char *init_data, size_t init_data_sz)
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{
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struct strset *set = calloc(1, sizeof(*set));
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struct hashmap *hash;
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int err = -ENOMEM;
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if (!set)
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return ERR_PTR(-ENOMEM);
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hash = hashmap__new(strset_hash_fn, strset_equal_fn, set);
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if (IS_ERR(hash))
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goto err_out;
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set->strs_data_max_len = max_data_sz;
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set->strs_hash = hash;
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if (init_data) {
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long off;
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set->strs_data = malloc(init_data_sz);
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if (!set->strs_data)
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goto err_out;
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memcpy(set->strs_data, init_data, init_data_sz);
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set->strs_data_len = init_data_sz;
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set->strs_data_cap = init_data_sz;
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for (off = 0; off < set->strs_data_len; off += strlen(set->strs_data + off) + 1) {
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/* hashmap__add() returns EEXIST if string with the same
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* content already is in the hash map
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*/
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err = hashmap__add(hash, (void *)off, (void *)off);
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if (err == -EEXIST)
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continue; /* duplicate */
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if (err)
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goto err_out;
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}
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}
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return set;
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err_out:
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strset__free(set);
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return ERR_PTR(err);
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}
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void strset__free(struct strset *set)
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{
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if (IS_ERR_OR_NULL(set))
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return;
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hashmap__free(set->strs_hash);
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free(set->strs_data);
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free(set);
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}
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size_t strset__data_size(const struct strset *set)
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{
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return set->strs_data_len;
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}
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const char *strset__data(const struct strset *set)
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{
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return set->strs_data;
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}
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static void *strset_add_str_mem(struct strset *set, size_t add_sz)
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{
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return libbpf_add_mem(&set->strs_data, &set->strs_data_cap, 1,
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set->strs_data_len, set->strs_data_max_len, add_sz);
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}
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/* Find string offset that corresponds to a given string *s*.
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* Returns:
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* - >0 offset into string data, if string is found;
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* - -ENOENT, if string is not in the string data;
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* - <0, on any other error.
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*/
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int strset__find_str(struct strset *set, const char *s)
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{
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long old_off, new_off, len;
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void *p;
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/* see strset__add_str() for why we do this */
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len = strlen(s) + 1;
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p = strset_add_str_mem(set, len);
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if (!p)
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return -ENOMEM;
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new_off = set->strs_data_len;
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memcpy(p, s, len);
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if (hashmap__find(set->strs_hash, (void *)new_off, (void **)&old_off))
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return old_off;
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return -ENOENT;
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}
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/* Add a string s to the string data. If the string already exists, return its
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* offset within string data.
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* Returns:
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* - > 0 offset into string data, on success;
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* - < 0, on error.
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*/
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int strset__add_str(struct strset *set, const char *s)
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{
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long old_off, new_off, len;
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void *p;
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int err;
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/* Hashmap keys are always offsets within set->strs_data, so to even
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* look up some string from the "outside", we need to first append it
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* at the end, so that it can be addressed with an offset. Luckily,
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* until set->strs_data_len is incremented, that string is just a piece
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* of garbage for the rest of the code, so no harm, no foul. On the
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* other hand, if the string is unique, it's already appended and
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* ready to be used, only a simple set->strs_data_len increment away.
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*/
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len = strlen(s) + 1;
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p = strset_add_str_mem(set, len);
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if (!p)
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return -ENOMEM;
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new_off = set->strs_data_len;
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memcpy(p, s, len);
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/* Now attempt to add the string, but only if the string with the same
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* contents doesn't exist already (HASHMAP_ADD strategy). If such
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* string exists, we'll get its offset in old_off (that's old_key).
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*/
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err = hashmap__insert(set->strs_hash, (void *)new_off, (void *)new_off,
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HASHMAP_ADD, (const void **)&old_off, NULL);
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if (err == -EEXIST)
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return old_off; /* duplicated string, return existing offset */
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if (err)
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return err;
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set->strs_data_len += len; /* new unique string, adjust data length */
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return new_off;
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}
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