| /* |
| * |
| * Copyright 2015, Google Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions are |
| * met: |
| * |
| * * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following disclaimer |
| * in the documentation and/or other materials provided with the |
| * distribution. |
| * * Neither the name of Google Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #include "src/core/iomgr/sockaddr.h" |
| #include "src/core/transport/metadata.h" |
| |
| #include <assert.h> |
| #include <stddef.h> |
| #include <string.h> |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/atm.h> |
| #include <grpc/support/log.h> |
| #include "src/core/support/murmur_hash.h" |
| #include "src/core/transport/chttp2/bin_encoder.h" |
| #include <grpc/support/time.h> |
| |
| #define INITIAL_STRTAB_CAPACITY 4 |
| #define INITIAL_MDTAB_CAPACITY 4 |
| |
| typedef struct internal_string { |
| /* must be byte compatible with grpc_mdstr */ |
| gpr_slice slice; |
| gpr_uint32 hash; |
| |
| /* private only data */ |
| gpr_uint32 refs; |
| gpr_uint8 has_base64_and_huffman_encoded; |
| gpr_slice_refcount refcount; |
| |
| gpr_slice base64_and_huffman; |
| |
| grpc_mdctx *context; |
| |
| struct internal_string *bucket_next; |
| } internal_string; |
| |
| typedef struct internal_metadata { |
| /* must be byte compatible with grpc_mdelem */ |
| internal_string *key; |
| internal_string *value; |
| |
| gpr_atm refcnt; |
| |
| /* private only data */ |
| void *user_data; |
| void (*destroy_user_data)(void *user_data); |
| |
| grpc_mdctx *context; |
| struct internal_metadata *bucket_next; |
| } internal_metadata; |
| |
| struct grpc_mdctx { |
| gpr_uint32 hash_seed; |
| int refs; |
| |
| gpr_mu mu; |
| |
| internal_string **strtab; |
| size_t strtab_count; |
| size_t strtab_capacity; |
| |
| internal_metadata **mdtab; |
| size_t mdtab_count; |
| size_t mdtab_free; |
| size_t mdtab_capacity; |
| }; |
| |
| static void internal_string_ref(internal_string *s); |
| static void internal_string_unref(internal_string *s); |
| static void discard_metadata(grpc_mdctx *ctx); |
| static void gc_mdtab(grpc_mdctx *ctx); |
| static void metadata_context_destroy_locked(grpc_mdctx *ctx); |
| |
| static void lock(grpc_mdctx *ctx) { gpr_mu_lock(&ctx->mu); } |
| |
| static void unlock(grpc_mdctx *ctx) { |
| /* If the context has been orphaned we'd like to delete it soon. We check |
| conditions in unlock as it signals the end of mutations on a context. |
| |
| We need to ensure all grpc_mdelem and grpc_mdstr elements have been deleted |
| first. This is equivalent to saying that both tables have zero counts, |
| which is equivalent to saying that strtab_count is zero (as mdelem's MUST |
| reference an mdstr for their key and value slots). |
| |
| To encourage that to happen, we start discarding zero reference count |
| mdelems on every unlock (instead of the usual 'I'm too loaded' trigger |
| case), since otherwise we can be stuck waiting for a garbage collection |
| that will never happen. */ |
| if (ctx->refs == 0) { |
| /* uncomment if you're having trouble diagnosing an mdelem leak to make |
| things clearer (slows down destruction a lot, however) */ |
| gc_mdtab(ctx); |
| if (ctx->mdtab_count && ctx->mdtab_count == ctx->mdtab_free) { |
| discard_metadata(ctx); |
| } |
| if (ctx->strtab_count == 0) { |
| metadata_context_destroy_locked(ctx); |
| return; |
| } |
| } |
| gpr_mu_unlock(&ctx->mu); |
| } |
| |
| static void ref_md_locked(internal_metadata *md) { |
| if (0 == gpr_atm_no_barrier_fetch_add(&md->refcnt, 1)) { |
| md->context->mdtab_free--; |
| } |
| } |
| |
| grpc_mdctx *grpc_mdctx_create_with_seed(gpr_uint32 seed) { |
| grpc_mdctx *ctx = gpr_malloc(sizeof(grpc_mdctx)); |
| |
| ctx->refs = 1; |
| ctx->hash_seed = seed; |
| gpr_mu_init(&ctx->mu); |
| ctx->strtab = gpr_malloc(sizeof(internal_string *) * INITIAL_STRTAB_CAPACITY); |
| memset(ctx->strtab, 0, sizeof(grpc_mdstr *) * INITIAL_STRTAB_CAPACITY); |
| ctx->strtab_count = 0; |
| ctx->strtab_capacity = INITIAL_STRTAB_CAPACITY; |
| ctx->mdtab = gpr_malloc(sizeof(internal_metadata *) * INITIAL_MDTAB_CAPACITY); |
| memset(ctx->mdtab, 0, sizeof(grpc_mdelem *) * INITIAL_MDTAB_CAPACITY); |
| ctx->mdtab_count = 0; |
| ctx->mdtab_capacity = INITIAL_MDTAB_CAPACITY; |
| ctx->mdtab_free = 0; |
| |
| return ctx; |
| } |
| |
| grpc_mdctx *grpc_mdctx_create(void) { |
| /* This seed is used to prevent remote connections from controlling hash table |
| * collisions. It needs to be somewhat unpredictable to a remote connection. |
| */ |
| return grpc_mdctx_create_with_seed(gpr_now().tv_nsec); |
| } |
| |
| static void discard_metadata(grpc_mdctx *ctx) { |
| size_t i; |
| internal_metadata *next, *cur; |
| |
| for (i = 0; i < ctx->mdtab_capacity; i++) { |
| cur = ctx->mdtab[i]; |
| while (cur) { |
| GPR_ASSERT(gpr_atm_acq_load(&cur->refcnt) == 0); |
| next = cur->bucket_next; |
| internal_string_unref(cur->key); |
| internal_string_unref(cur->value); |
| if (cur->user_data) { |
| cur->destroy_user_data(cur->user_data); |
| } |
| gpr_free(cur); |
| cur = next; |
| ctx->mdtab_free--; |
| ctx->mdtab_count--; |
| } |
| ctx->mdtab[i] = NULL; |
| } |
| } |
| |
| static void metadata_context_destroy_locked(grpc_mdctx *ctx) { |
| GPR_ASSERT(ctx->strtab_count == 0); |
| GPR_ASSERT(ctx->mdtab_count == 0); |
| GPR_ASSERT(ctx->mdtab_free == 0); |
| gpr_free(ctx->strtab); |
| gpr_free(ctx->mdtab); |
| gpr_mu_unlock(&ctx->mu); |
| gpr_mu_destroy(&ctx->mu); |
| gpr_free(ctx); |
| } |
| |
| void grpc_mdctx_ref(grpc_mdctx *ctx) { |
| lock(ctx); |
| GPR_ASSERT(ctx->refs > 0); |
| ctx->refs++; |
| unlock(ctx); |
| } |
| |
| void grpc_mdctx_unref(grpc_mdctx *ctx) { |
| lock(ctx); |
| GPR_ASSERT(ctx->refs > 0); |
| ctx->refs--; |
| unlock(ctx); |
| } |
| |
| static void grow_strtab(grpc_mdctx *ctx) { |
| size_t capacity = ctx->strtab_capacity * 2; |
| size_t i; |
| internal_string **strtab = gpr_malloc(sizeof(internal_string *) * capacity); |
| internal_string *s, *next; |
| memset(strtab, 0, sizeof(internal_string *) * capacity); |
| |
| for (i = 0; i < ctx->strtab_capacity; i++) { |
| for (s = ctx->strtab[i]; s; s = next) { |
| next = s->bucket_next; |
| s->bucket_next = strtab[s->hash % capacity]; |
| strtab[s->hash % capacity] = s; |
| } |
| } |
| |
| gpr_free(ctx->strtab); |
| ctx->strtab = strtab; |
| ctx->strtab_capacity = capacity; |
| } |
| |
| static void internal_destroy_string(internal_string *is) { |
| internal_string **prev_next; |
| internal_string *cur; |
| grpc_mdctx *ctx = is->context; |
| if (is->has_base64_and_huffman_encoded) { |
| gpr_slice_unref(is->base64_and_huffman); |
| } |
| for (prev_next = &ctx->strtab[is->hash % ctx->strtab_capacity], |
| cur = *prev_next; |
| cur != is; prev_next = &cur->bucket_next, cur = cur->bucket_next) |
| ; |
| *prev_next = cur->bucket_next; |
| ctx->strtab_count--; |
| gpr_free(is); |
| } |
| |
| static void internal_string_ref(internal_string *s) { ++s->refs; } |
| |
| static void internal_string_unref(internal_string *s) { |
| GPR_ASSERT(s->refs > 0); |
| if (0 == --s->refs) { |
| internal_destroy_string(s); |
| } |
| } |
| |
| static void slice_ref(void *p) { |
| internal_string *is = |
| (internal_string *)((char *)p - offsetof(internal_string, refcount)); |
| grpc_mdctx *ctx = is->context; |
| lock(ctx); |
| internal_string_ref(is); |
| unlock(ctx); |
| } |
| |
| static void slice_unref(void *p) { |
| internal_string *is = |
| (internal_string *)((char *)p - offsetof(internal_string, refcount)); |
| grpc_mdctx *ctx = is->context; |
| lock(ctx); |
| internal_string_unref(is); |
| unlock(ctx); |
| } |
| |
| grpc_mdstr *grpc_mdstr_from_string(grpc_mdctx *ctx, const char *str) { |
| return grpc_mdstr_from_buffer(ctx, (const gpr_uint8 *)str, strlen(str)); |
| } |
| |
| grpc_mdstr *grpc_mdstr_from_slice(grpc_mdctx *ctx, gpr_slice slice) { |
| grpc_mdstr *result = grpc_mdstr_from_buffer(ctx, GPR_SLICE_START_PTR(slice), |
| GPR_SLICE_LENGTH(slice)); |
| gpr_slice_unref(slice); |
| return result; |
| } |
| |
| grpc_mdstr *grpc_mdstr_from_buffer(grpc_mdctx *ctx, const gpr_uint8 *buf, |
| size_t length) { |
| gpr_uint32 hash = gpr_murmur_hash3(buf, length, ctx->hash_seed); |
| internal_string *s; |
| |
| lock(ctx); |
| |
| /* search for an existing string */ |
| for (s = ctx->strtab[hash % ctx->strtab_capacity]; s; s = s->bucket_next) { |
| if (s->hash == hash && GPR_SLICE_LENGTH(s->slice) == length && |
| 0 == memcmp(buf, GPR_SLICE_START_PTR(s->slice), length)) { |
| internal_string_ref(s); |
| unlock(ctx); |
| return (grpc_mdstr *)s; |
| } |
| } |
| |
| /* not found: create a new string */ |
| if (length + 1 < GPR_SLICE_INLINED_SIZE) { |
| /* string data goes directly into the slice */ |
| s = gpr_malloc(sizeof(internal_string)); |
| s->refs = 1; |
| s->slice.refcount = NULL; |
| memcpy(s->slice.data.inlined.bytes, buf, length); |
| s->slice.data.inlined.bytes[length] = 0; |
| s->slice.data.inlined.length = length; |
| } else { |
| /* string data goes after the internal_string header, and we +1 for null |
| terminator */ |
| s = gpr_malloc(sizeof(internal_string) + length + 1); |
| s->refs = 1; |
| s->refcount.ref = slice_ref; |
| s->refcount.unref = slice_unref; |
| s->slice.refcount = &s->refcount; |
| s->slice.data.refcounted.bytes = (gpr_uint8 *)(s + 1); |
| s->slice.data.refcounted.length = length; |
| memcpy(s->slice.data.refcounted.bytes, buf, length); |
| /* add a null terminator for cheap c string conversion when desired */ |
| s->slice.data.refcounted.bytes[length] = 0; |
| } |
| s->has_base64_and_huffman_encoded = 0; |
| s->hash = hash; |
| s->context = ctx; |
| s->bucket_next = ctx->strtab[hash % ctx->strtab_capacity]; |
| ctx->strtab[hash % ctx->strtab_capacity] = s; |
| |
| ctx->strtab_count++; |
| |
| if (ctx->strtab_count > ctx->strtab_capacity * 2) { |
| grow_strtab(ctx); |
| } |
| |
| unlock(ctx); |
| |
| return (grpc_mdstr *)s; |
| } |
| |
| static void gc_mdtab(grpc_mdctx *ctx) { |
| size_t i; |
| internal_metadata **prev_next; |
| internal_metadata *md, *next; |
| |
| for (i = 0; i < ctx->mdtab_capacity; i++) { |
| prev_next = &ctx->mdtab[i]; |
| for (md = ctx->mdtab[i]; md; md = next) { |
| next = md->bucket_next; |
| if (gpr_atm_acq_load(&md->refcnt) == 0) { |
| internal_string_unref(md->key); |
| internal_string_unref(md->value); |
| if (md->user_data) { |
| md->destroy_user_data(md->user_data); |
| } |
| gpr_free(md); |
| *prev_next = next; |
| ctx->mdtab_free--; |
| ctx->mdtab_count--; |
| } else { |
| prev_next = &md->bucket_next; |
| } |
| } |
| } |
| |
| GPR_ASSERT(ctx->mdtab_free == 0); |
| } |
| |
| static void grow_mdtab(grpc_mdctx *ctx) { |
| size_t capacity = ctx->mdtab_capacity * 2; |
| size_t i; |
| internal_metadata **mdtab = |
| gpr_malloc(sizeof(internal_metadata *) * capacity); |
| internal_metadata *md, *next; |
| gpr_uint32 hash; |
| memset(mdtab, 0, sizeof(internal_metadata *) * capacity); |
| |
| for (i = 0; i < ctx->mdtab_capacity; i++) { |
| for (md = ctx->mdtab[i]; md; md = next) { |
| hash = GRPC_MDSTR_KV_HASH(md->key->hash, md->value->hash); |
| next = md->bucket_next; |
| md->bucket_next = mdtab[hash % capacity]; |
| mdtab[hash % capacity] = md; |
| } |
| } |
| |
| gpr_free(ctx->mdtab); |
| ctx->mdtab = mdtab; |
| ctx->mdtab_capacity = capacity; |
| } |
| |
| static void rehash_mdtab(grpc_mdctx *ctx) { |
| if (ctx->mdtab_free > ctx->mdtab_capacity / 4) { |
| gc_mdtab(ctx); |
| } else { |
| grow_mdtab(ctx); |
| } |
| } |
| |
| grpc_mdelem *grpc_mdelem_from_metadata_strings(grpc_mdctx *ctx, |
| grpc_mdstr *mkey, |
| grpc_mdstr *mvalue) { |
| internal_string *key = (internal_string *)mkey; |
| internal_string *value = (internal_string *)mvalue; |
| gpr_uint32 hash = GRPC_MDSTR_KV_HASH(mkey->hash, mvalue->hash); |
| internal_metadata *md; |
| |
| GPR_ASSERT(key->context == ctx); |
| GPR_ASSERT(value->context == ctx); |
| |
| lock(ctx); |
| |
| /* search for an existing pair */ |
| for (md = ctx->mdtab[hash % ctx->mdtab_capacity]; md; md = md->bucket_next) { |
| if (md->key == key && md->value == value) { |
| ref_md_locked(md); |
| internal_string_unref(key); |
| internal_string_unref(value); |
| unlock(ctx); |
| return (grpc_mdelem *)md; |
| } |
| } |
| |
| /* not found: create a new pair */ |
| md = gpr_malloc(sizeof(internal_metadata)); |
| gpr_atm_rel_store(&md->refcnt, 1); |
| md->context = ctx; |
| md->key = key; |
| md->value = value; |
| md->user_data = NULL; |
| md->destroy_user_data = NULL; |
| md->bucket_next = ctx->mdtab[hash % ctx->mdtab_capacity]; |
| ctx->mdtab[hash % ctx->mdtab_capacity] = md; |
| ctx->mdtab_count++; |
| |
| if (ctx->mdtab_count > ctx->mdtab_capacity * 2) { |
| rehash_mdtab(ctx); |
| } |
| |
| unlock(ctx); |
| |
| return (grpc_mdelem *)md; |
| } |
| |
| grpc_mdelem *grpc_mdelem_from_strings(grpc_mdctx *ctx, const char *key, |
| const char *value) { |
| return grpc_mdelem_from_metadata_strings(ctx, |
| grpc_mdstr_from_string(ctx, key), |
| grpc_mdstr_from_string(ctx, value)); |
| } |
| |
| grpc_mdelem *grpc_mdelem_from_slices(grpc_mdctx *ctx, gpr_slice key, |
| gpr_slice value) { |
| return grpc_mdelem_from_metadata_strings(ctx, grpc_mdstr_from_slice(ctx, key), |
| grpc_mdstr_from_slice(ctx, value)); |
| } |
| |
| grpc_mdelem *grpc_mdelem_from_string_and_buffer(grpc_mdctx *ctx, |
| const char *key, |
| const gpr_uint8 *value, |
| size_t value_length) { |
| return grpc_mdelem_from_metadata_strings( |
| ctx, grpc_mdstr_from_string(ctx, key), |
| grpc_mdstr_from_buffer(ctx, value, value_length)); |
| } |
| |
| grpc_mdelem *grpc_mdelem_ref(grpc_mdelem *gmd) { |
| internal_metadata *md = (internal_metadata *)gmd; |
| /* we can assume the ref count is >= 1 as the application is calling |
| this function - meaning that no adjustment to mdtab_free is necessary, |
| simplifying the logic here to be just an atomic increment */ |
| /* use C assert to have this removed in opt builds */ |
| assert(gpr_atm_no_barrier_load(&md->refcnt) >= 1); |
| gpr_atm_no_barrier_fetch_add(&md->refcnt, 1); |
| return gmd; |
| } |
| |
| void grpc_mdelem_unref(grpc_mdelem *gmd) { |
| internal_metadata *md = (internal_metadata *)gmd; |
| grpc_mdctx *ctx = md->context; |
| lock(ctx); |
| assert(gpr_atm_no_barrier_load(&md->refcnt) >= 1); |
| if (1 == gpr_atm_full_fetch_add(&md->refcnt, -1)) { |
| ctx->mdtab_free++; |
| } |
| unlock(ctx); |
| } |
| |
| const char *grpc_mdstr_as_c_string(grpc_mdstr *s) { |
| return (const char *)GPR_SLICE_START_PTR(s->slice); |
| } |
| |
| grpc_mdstr *grpc_mdstr_ref(grpc_mdstr *gs) { |
| internal_string *s = (internal_string *)gs; |
| grpc_mdctx *ctx = s->context; |
| lock(ctx); |
| internal_string_ref(s); |
| unlock(ctx); |
| return gs; |
| } |
| |
| void grpc_mdstr_unref(grpc_mdstr *gs) { |
| internal_string *s = (internal_string *)gs; |
| grpc_mdctx *ctx = s->context; |
| lock(ctx); |
| internal_string_unref(s); |
| unlock(ctx); |
| } |
| |
| size_t grpc_mdctx_get_mdtab_capacity_test_only(grpc_mdctx *ctx) { |
| return ctx->mdtab_capacity; |
| } |
| |
| size_t grpc_mdctx_get_mdtab_count_test_only(grpc_mdctx *ctx) { |
| return ctx->mdtab_count; |
| } |
| |
| size_t grpc_mdctx_get_mdtab_free_test_only(grpc_mdctx *ctx) { |
| return ctx->mdtab_free; |
| } |
| |
| void *grpc_mdelem_get_user_data(grpc_mdelem *md, |
| void (*if_destroy_func)(void *)) { |
| internal_metadata *im = (internal_metadata *)md; |
| return im->destroy_user_data == if_destroy_func ? im->user_data : NULL; |
| } |
| |
| void grpc_mdelem_set_user_data(grpc_mdelem *md, void (*destroy_func)(void *), |
| void *user_data) { |
| internal_metadata *im = (internal_metadata *)md; |
| GPR_ASSERT((user_data == NULL) == (destroy_func == NULL)); |
| if (im->destroy_user_data) { |
| im->destroy_user_data(im->user_data); |
| } |
| im->destroy_user_data = destroy_func; |
| im->user_data = user_data; |
| } |
| |
| gpr_slice grpc_mdstr_as_base64_encoded_and_huffman_compressed(grpc_mdstr *gs) { |
| internal_string *s = (internal_string *)gs; |
| gpr_slice slice; |
| grpc_mdctx *ctx = s->context; |
| lock(ctx); |
| if (!s->has_base64_and_huffman_encoded) { |
| s->base64_and_huffman = |
| grpc_chttp2_base64_encode_and_huffman_compress(s->slice); |
| s->has_base64_and_huffman_encoded = 1; |
| } |
| slice = s->base64_and_huffman; |
| unlock(ctx); |
| return slice; |
| } |
| |
| void grpc_mdctx_lock(grpc_mdctx *ctx) { lock(ctx); } |
| |
| void grpc_mdctx_locked_mdelem_unref(grpc_mdctx *ctx, grpc_mdelem *gmd) { |
| internal_metadata *md = (internal_metadata *)gmd; |
| grpc_mdctx *elem_ctx = md->context; |
| GPR_ASSERT(ctx == elem_ctx); |
| assert(gpr_atm_no_barrier_load(&md->refcnt) >= 1); |
| if (1 == gpr_atm_full_fetch_add(&md->refcnt, -1)) { |
| ctx->mdtab_free++; |
| } |
| } |
| |
| void grpc_mdctx_unlock(grpc_mdctx *ctx) { unlock(ctx); } |
| |
| int grpc_mdstr_is_legal_header(grpc_mdstr *s) { |
| /* TODO(ctiller): consider caching this, or computing it on construction */ |
| const gpr_uint8 *p = GPR_SLICE_START_PTR(s->slice); |
| const gpr_uint8 *e = GPR_SLICE_END_PTR(s->slice); |
| for (; p != e; p++) { |
| if (*p < 32 || *p > 126) return 0; |
| } |
| return 1; |
| } |
| |
| int grpc_mdstr_is_bin_suffixed(grpc_mdstr *s) { |
| /* TODO(ctiller): consider caching this */ |
| return grpc_is_binary_header((const char *)GPR_SLICE_START_PTR(s->slice), |
| GPR_SLICE_LENGTH(s->slice)); |
| } |