Mercurial > hg > nginx-quic
view src/core/ngx_hash.c @ 8551:c35b255d80dc quic
HTTP/3: close connection on keepalive_requests * 2.
After receiving GOAWAY, client is not supposed to create new streams. However,
until client reads this frame, we allow it to create new streams, which are
gracefully rejected. To prevent client from abusing this algorithm, a new
limit is introduced. Upon reaching keepalive_requests * 2, server now closes
the entire QUIC connection claiming excessive load.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Thu, 29 Jul 2021 16:01:37 +0300 |
parents | eb9c7fb796d5 |
children | 2a7155733855 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> void * ngx_hash_find(ngx_hash_t *hash, ngx_uint_t key, u_char *name, size_t len) { ngx_uint_t i; ngx_hash_elt_t *elt; #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "hf:\"%*s\"", len, name); #endif elt = hash->buckets[key % hash->size]; if (elt == NULL) { return NULL; } while (elt->value) { if (len != (size_t) elt->len) { goto next; } for (i = 0; i < len; i++) { if (name[i] != elt->name[i]) { goto next; } } return elt->value; next: elt = (ngx_hash_elt_t *) ngx_align_ptr(&elt->name[0] + elt->len, sizeof(void *)); continue; } return NULL; } void * ngx_hash_find_wc_head(ngx_hash_wildcard_t *hwc, u_char *name, size_t len) { void *value; ngx_uint_t i, n, key; #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "wch:\"%*s\"", len, name); #endif n = len; while (n) { if (name[n - 1] == '.') { break; } n--; } key = 0; for (i = n; i < len; i++) { key = ngx_hash(key, name[i]); } #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "key:\"%ui\"", key); #endif value = ngx_hash_find(&hwc->hash, key, &name[n], len - n); #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "value:\"%p\"", value); #endif if (value) { /* * the 2 low bits of value have the special meaning: * 00 - value is data pointer for both "example.com" * and "*.example.com"; * 01 - value is data pointer for "*.example.com" only; * 10 - value is pointer to wildcard hash allowing * both "example.com" and "*.example.com"; * 11 - value is pointer to wildcard hash allowing * "*.example.com" only. */ if ((uintptr_t) value & 2) { if (n == 0) { /* "example.com" */ if ((uintptr_t) value & 1) { return NULL; } hwc = (ngx_hash_wildcard_t *) ((uintptr_t) value & (uintptr_t) ~3); return hwc->value; } hwc = (ngx_hash_wildcard_t *) ((uintptr_t) value & (uintptr_t) ~3); value = ngx_hash_find_wc_head(hwc, name, n - 1); if (value) { return value; } return hwc->value; } if ((uintptr_t) value & 1) { if (n == 0) { /* "example.com" */ return NULL; } return (void *) ((uintptr_t) value & (uintptr_t) ~3); } return value; } return hwc->value; } void * ngx_hash_find_wc_tail(ngx_hash_wildcard_t *hwc, u_char *name, size_t len) { void *value; ngx_uint_t i, key; #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "wct:\"%*s\"", len, name); #endif key = 0; for (i = 0; i < len; i++) { if (name[i] == '.') { break; } key = ngx_hash(key, name[i]); } if (i == len) { return NULL; } #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "key:\"%ui\"", key); #endif value = ngx_hash_find(&hwc->hash, key, name, i); #if 0 ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, 0, "value:\"%p\"", value); #endif if (value) { /* * the 2 low bits of value have the special meaning: * 00 - value is data pointer; * 11 - value is pointer to wildcard hash allowing "example.*". */ if ((uintptr_t) value & 2) { i++; hwc = (ngx_hash_wildcard_t *) ((uintptr_t) value & (uintptr_t) ~3); value = ngx_hash_find_wc_tail(hwc, &name[i], len - i); if (value) { return value; } return hwc->value; } return value; } return hwc->value; } void * ngx_hash_find_combined(ngx_hash_combined_t *hash, ngx_uint_t key, u_char *name, size_t len) { void *value; if (hash->hash.buckets) { value = ngx_hash_find(&hash->hash, key, name, len); if (value) { return value; } } if (len == 0) { return NULL; } if (hash->wc_head && hash->wc_head->hash.buckets) { value = ngx_hash_find_wc_head(hash->wc_head, name, len); if (value) { return value; } } if (hash->wc_tail && hash->wc_tail->hash.buckets) { value = ngx_hash_find_wc_tail(hash->wc_tail, name, len); if (value) { return value; } } return NULL; } #define NGX_HASH_ELT_SIZE(name) \ (sizeof(void *) + ngx_align((name)->key.len + 2, sizeof(void *))) ngx_int_t ngx_hash_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts) { u_char *elts; size_t len; u_short *test; ngx_uint_t i, n, key, size, start, bucket_size; ngx_hash_elt_t *elt, **buckets; if (hinit->max_size == 0) { ngx_log_error(NGX_LOG_EMERG, hinit->pool->log, 0, "could not build %s, you should " "increase %s_max_size: %i", hinit->name, hinit->name, hinit->max_size); return NGX_ERROR; } if (hinit->bucket_size > 65536 - ngx_cacheline_size) { ngx_log_error(NGX_LOG_EMERG, hinit->pool->log, 0, "could not build %s, too large " "%s_bucket_size: %i", hinit->name, hinit->name, hinit->bucket_size); return NGX_ERROR; } for (n = 0; n < nelts; n++) { if (hinit->bucket_size < NGX_HASH_ELT_SIZE(&names[n]) + sizeof(void *)) { ngx_log_error(NGX_LOG_EMERG, hinit->pool->log, 0, "could not build %s, you should " "increase %s_bucket_size: %i", hinit->name, hinit->name, hinit->bucket_size); return NGX_ERROR; } } test = ngx_alloc(hinit->max_size * sizeof(u_short), hinit->pool->log); if (test == NULL) { return NGX_ERROR; } bucket_size = hinit->bucket_size - sizeof(void *); start = nelts / (bucket_size / (2 * sizeof(void *))); start = start ? start : 1; if (hinit->max_size > 10000 && nelts && hinit->max_size / nelts < 100) { start = hinit->max_size - 1000; } for (size = start; size <= hinit->max_size; size++) { ngx_memzero(test, size * sizeof(u_short)); for (n = 0; n < nelts; n++) { if (names[n].key.data == NULL) { continue; } key = names[n].key_hash % size; len = test[key] + NGX_HASH_ELT_SIZE(&names[n]); #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "%ui: %ui %uz \"%V\"", size, key, len, &names[n].key); #endif if (len > bucket_size) { goto next; } test[key] = (u_short) len; } goto found; next: continue; } size = hinit->max_size; ngx_log_error(NGX_LOG_WARN, hinit->pool->log, 0, "could not build optimal %s, you should increase " "either %s_max_size: %i or %s_bucket_size: %i; " "ignoring %s_bucket_size", hinit->name, hinit->name, hinit->max_size, hinit->name, hinit->bucket_size, hinit->name); found: for (i = 0; i < size; i++) { test[i] = sizeof(void *); } for (n = 0; n < nelts; n++) { if (names[n].key.data == NULL) { continue; } key = names[n].key_hash % size; len = test[key] + NGX_HASH_ELT_SIZE(&names[n]); if (len > 65536 - ngx_cacheline_size) { ngx_log_error(NGX_LOG_EMERG, hinit->pool->log, 0, "could not build %s, you should " "increase %s_max_size: %i", hinit->name, hinit->name, hinit->max_size); ngx_free(test); return NGX_ERROR; } test[key] = (u_short) len; } len = 0; for (i = 0; i < size; i++) { if (test[i] == sizeof(void *)) { continue; } test[i] = (u_short) (ngx_align(test[i], ngx_cacheline_size)); len += test[i]; } if (hinit->hash == NULL) { hinit->hash = ngx_pcalloc(hinit->pool, sizeof(ngx_hash_wildcard_t) + size * sizeof(ngx_hash_elt_t *)); if (hinit->hash == NULL) { ngx_free(test); return NGX_ERROR; } buckets = (ngx_hash_elt_t **) ((u_char *) hinit->hash + sizeof(ngx_hash_wildcard_t)); } else { buckets = ngx_pcalloc(hinit->pool, size * sizeof(ngx_hash_elt_t *)); if (buckets == NULL) { ngx_free(test); return NGX_ERROR; } } elts = ngx_palloc(hinit->pool, len + ngx_cacheline_size); if (elts == NULL) { ngx_free(test); return NGX_ERROR; } elts = ngx_align_ptr(elts, ngx_cacheline_size); for (i = 0; i < size; i++) { if (test[i] == sizeof(void *)) { continue; } buckets[i] = (ngx_hash_elt_t *) elts; elts += test[i]; } for (i = 0; i < size; i++) { test[i] = 0; } for (n = 0; n < nelts; n++) { if (names[n].key.data == NULL) { continue; } key = names[n].key_hash % size; elt = (ngx_hash_elt_t *) ((u_char *) buckets[key] + test[key]); elt->value = names[n].value; elt->len = (u_short) names[n].key.len; ngx_strlow(elt->name, names[n].key.data, names[n].key.len); test[key] = (u_short) (test[key] + NGX_HASH_ELT_SIZE(&names[n])); } for (i = 0; i < size; i++) { if (buckets[i] == NULL) { continue; } elt = (ngx_hash_elt_t *) ((u_char *) buckets[i] + test[i]); elt->value = NULL; } ngx_free(test); hinit->hash->buckets = buckets; hinit->hash->size = size; #if 0 for (i = 0; i < size; i++) { ngx_str_t val; ngx_uint_t key; elt = buckets[i]; if (elt == NULL) { ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "%ui: NULL", i); continue; } while (elt->value) { val.len = elt->len; val.data = &elt->name[0]; key = hinit->key(val.data, val.len); ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "%ui: %p \"%V\" %ui", i, elt, &val, key); elt = (ngx_hash_elt_t *) ngx_align_ptr(&elt->name[0] + elt->len, sizeof(void *)); } } #endif return NGX_OK; } ngx_int_t ngx_hash_wildcard_init(ngx_hash_init_t *hinit, ngx_hash_key_t *names, ngx_uint_t nelts) { size_t len, dot_len; ngx_uint_t i, n, dot; ngx_array_t curr_names, next_names; ngx_hash_key_t *name, *next_name; ngx_hash_init_t h; ngx_hash_wildcard_t *wdc; if (ngx_array_init(&curr_names, hinit->temp_pool, nelts, sizeof(ngx_hash_key_t)) != NGX_OK) { return NGX_ERROR; } if (ngx_array_init(&next_names, hinit->temp_pool, nelts, sizeof(ngx_hash_key_t)) != NGX_OK) { return NGX_ERROR; } for (n = 0; n < nelts; n = i) { #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "wc0: \"%V\"", &names[n].key); #endif dot = 0; for (len = 0; len < names[n].key.len; len++) { if (names[n].key.data[len] == '.') { dot = 1; break; } } name = ngx_array_push(&curr_names); if (name == NULL) { return NGX_ERROR; } name->key.len = len; name->key.data = names[n].key.data; name->key_hash = hinit->key(name->key.data, name->key.len); name->value = names[n].value; #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "wc1: \"%V\" %ui", &name->key, dot); #endif dot_len = len + 1; if (dot) { len++; } next_names.nelts = 0; if (names[n].key.len != len) { next_name = ngx_array_push(&next_names); if (next_name == NULL) { return NGX_ERROR; } next_name->key.len = names[n].key.len - len; next_name->key.data = names[n].key.data + len; next_name->key_hash = 0; next_name->value = names[n].value; #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "wc2: \"%V\"", &next_name->key); #endif } for (i = n + 1; i < nelts; i++) { if (ngx_strncmp(names[n].key.data, names[i].key.data, len) != 0) { break; } if (!dot && names[i].key.len > len && names[i].key.data[len] != '.') { break; } next_name = ngx_array_push(&next_names); if (next_name == NULL) { return NGX_ERROR; } next_name->key.len = names[i].key.len - dot_len; next_name->key.data = names[i].key.data + dot_len; next_name->key_hash = 0; next_name->value = names[i].value; #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "wc3: \"%V\"", &next_name->key); #endif } if (next_names.nelts) { h = *hinit; h.hash = NULL; if (ngx_hash_wildcard_init(&h, (ngx_hash_key_t *) next_names.elts, next_names.nelts) != NGX_OK) { return NGX_ERROR; } wdc = (ngx_hash_wildcard_t *) h.hash; if (names[n].key.len == len) { wdc->value = names[n].value; } name->value = (void *) ((uintptr_t) wdc | (dot ? 3 : 2)); } else if (dot) { name->value = (void *) ((uintptr_t) name->value | 1); } } if (ngx_hash_init(hinit, (ngx_hash_key_t *) curr_names.elts, curr_names.nelts) != NGX_OK) { return NGX_ERROR; } return NGX_OK; } ngx_uint_t ngx_hash_key(u_char *data, size_t len) { ngx_uint_t i, key; key = 0; for (i = 0; i < len; i++) { key = ngx_hash(key, data[i]); } return key; } ngx_uint_t ngx_hash_key_lc(u_char *data, size_t len) { ngx_uint_t i, key; key = 0; for (i = 0; i < len; i++) { key = ngx_hash(key, ngx_tolower(data[i])); } return key; } ngx_uint_t ngx_hash_strlow(u_char *dst, u_char *src, size_t n) { ngx_uint_t key; key = 0; while (n--) { *dst = ngx_tolower(*src); key = ngx_hash(key, *dst); dst++; src++; } return key; } ngx_int_t ngx_hash_keys_array_init(ngx_hash_keys_arrays_t *ha, ngx_uint_t type) { ngx_uint_t asize; if (type == NGX_HASH_SMALL) { asize = 4; ha->hsize = 107; } else { asize = NGX_HASH_LARGE_ASIZE; ha->hsize = NGX_HASH_LARGE_HSIZE; } if (ngx_array_init(&ha->keys, ha->temp_pool, asize, sizeof(ngx_hash_key_t)) != NGX_OK) { return NGX_ERROR; } if (ngx_array_init(&ha->dns_wc_head, ha->temp_pool, asize, sizeof(ngx_hash_key_t)) != NGX_OK) { return NGX_ERROR; } if (ngx_array_init(&ha->dns_wc_tail, ha->temp_pool, asize, sizeof(ngx_hash_key_t)) != NGX_OK) { return NGX_ERROR; } ha->keys_hash = ngx_pcalloc(ha->temp_pool, sizeof(ngx_array_t) * ha->hsize); if (ha->keys_hash == NULL) { return NGX_ERROR; } ha->dns_wc_head_hash = ngx_pcalloc(ha->temp_pool, sizeof(ngx_array_t) * ha->hsize); if (ha->dns_wc_head_hash == NULL) { return NGX_ERROR; } ha->dns_wc_tail_hash = ngx_pcalloc(ha->temp_pool, sizeof(ngx_array_t) * ha->hsize); if (ha->dns_wc_tail_hash == NULL) { return NGX_ERROR; } return NGX_OK; } ngx_int_t ngx_hash_add_key(ngx_hash_keys_arrays_t *ha, ngx_str_t *key, void *value, ngx_uint_t flags) { size_t len; u_char *p; ngx_str_t *name; ngx_uint_t i, k, n, skip, last; ngx_array_t *keys, *hwc; ngx_hash_key_t *hk; last = key->len; if (flags & NGX_HASH_WILDCARD_KEY) { /* * supported wildcards: * "*.example.com", ".example.com", and "www.example.*" */ n = 0; for (i = 0; i < key->len; i++) { if (key->data[i] == '*') { if (++n > 1) { return NGX_DECLINED; } } if (key->data[i] == '.' && key->data[i + 1] == '.') { return NGX_DECLINED; } if (key->data[i] == '\0') { return NGX_DECLINED; } } if (key->len > 1 && key->data[0] == '.') { skip = 1; goto wildcard; } if (key->len > 2) { if (key->data[0] == '*' && key->data[1] == '.') { skip = 2; goto wildcard; } if (key->data[i - 2] == '.' && key->data[i - 1] == '*') { skip = 0; last -= 2; goto wildcard; } } if (n) { return NGX_DECLINED; } } /* exact hash */ k = 0; for (i = 0; i < last; i++) { if (!(flags & NGX_HASH_READONLY_KEY)) { key->data[i] = ngx_tolower(key->data[i]); } k = ngx_hash(k, key->data[i]); } k %= ha->hsize; /* check conflicts in exact hash */ name = ha->keys_hash[k].elts; if (name) { for (i = 0; i < ha->keys_hash[k].nelts; i++) { if (last != name[i].len) { continue; } if (ngx_strncmp(key->data, name[i].data, last) == 0) { return NGX_BUSY; } } } else { if (ngx_array_init(&ha->keys_hash[k], ha->temp_pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NGX_ERROR; } } name = ngx_array_push(&ha->keys_hash[k]); if (name == NULL) { return NGX_ERROR; } *name = *key; hk = ngx_array_push(&ha->keys); if (hk == NULL) { return NGX_ERROR; } hk->key = *key; hk->key_hash = ngx_hash_key(key->data, last); hk->value = value; return NGX_OK; wildcard: /* wildcard hash */ k = ngx_hash_strlow(&key->data[skip], &key->data[skip], last - skip); k %= ha->hsize; if (skip == 1) { /* check conflicts in exact hash for ".example.com" */ name = ha->keys_hash[k].elts; if (name) { len = last - skip; for (i = 0; i < ha->keys_hash[k].nelts; i++) { if (len != name[i].len) { continue; } if (ngx_strncmp(&key->data[1], name[i].data, len) == 0) { return NGX_BUSY; } } } else { if (ngx_array_init(&ha->keys_hash[k], ha->temp_pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NGX_ERROR; } } name = ngx_array_push(&ha->keys_hash[k]); if (name == NULL) { return NGX_ERROR; } name->len = last - 1; name->data = ngx_pnalloc(ha->temp_pool, name->len); if (name->data == NULL) { return NGX_ERROR; } ngx_memcpy(name->data, &key->data[1], name->len); } if (skip) { /* * convert "*.example.com" to "com.example.\0" * and ".example.com" to "com.example\0" */ p = ngx_pnalloc(ha->temp_pool, last); if (p == NULL) { return NGX_ERROR; } len = 0; n = 0; for (i = last - 1; i; i--) { if (key->data[i] == '.') { ngx_memcpy(&p[n], &key->data[i + 1], len); n += len; p[n++] = '.'; len = 0; continue; } len++; } if (len) { ngx_memcpy(&p[n], &key->data[1], len); n += len; } p[n] = '\0'; hwc = &ha->dns_wc_head; keys = &ha->dns_wc_head_hash[k]; } else { /* convert "www.example.*" to "www.example\0" */ last++; p = ngx_pnalloc(ha->temp_pool, last); if (p == NULL) { return NGX_ERROR; } ngx_cpystrn(p, key->data, last); hwc = &ha->dns_wc_tail; keys = &ha->dns_wc_tail_hash[k]; } /* check conflicts in wildcard hash */ name = keys->elts; if (name) { len = last - skip; for (i = 0; i < keys->nelts; i++) { if (len != name[i].len) { continue; } if (ngx_strncmp(key->data + skip, name[i].data, len) == 0) { return NGX_BUSY; } } } else { if (ngx_array_init(keys, ha->temp_pool, 4, sizeof(ngx_str_t)) != NGX_OK) { return NGX_ERROR; } } name = ngx_array_push(keys); if (name == NULL) { return NGX_ERROR; } name->len = last - skip; name->data = ngx_pnalloc(ha->temp_pool, name->len); if (name->data == NULL) { return NGX_ERROR; } ngx_memcpy(name->data, key->data + skip, name->len); /* add to wildcard hash */ hk = ngx_array_push(hwc); if (hk == NULL) { return NGX_ERROR; } hk->key.len = last - 1; hk->key.data = p; hk->key_hash = 0; hk->value = value; return NGX_OK; }