Mercurial > hg > nginx-quic
view src/core/ngx_hash.c @ 6133:af7eba90645d
Win32: shared memory base addresses and remapping.
Two mechanisms are implemented to make it possible to store pointers
in shared memory on Windows, in particular on Windows Vista and later
versions with ASLR:
- The ngx_shm_remap() function added to allow remapping of a shared memory
zone to the address originally used for it in the master process. While
important, it doesn't solve the problem by itself as in many cases it's
not possible to use the address because of conflicts with other
allocations.
- We now create mappings at the same address in all processes by starting
mappings at predefined addresses normally unused by newborn processes.
These two mechanisms combined allow to use shared memory on Windows
almost without problems, including reloads.
Based on the patch by Sergey Brester:
http://mailman.nginx.org/pipermail/nginx-devel/2015-April/006836.html
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 27 Apr 2015 18:25:42 +0300 |
parents | f961c719fb09 |
children | ddf35e019a80 |
line wrap: on
line source
/* * 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; 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 the %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; test[key] = (u_short) (test[key] + NGX_HASH_ELT_SIZE(&names[n])); #if 0 ngx_log_error(NGX_LOG_ALERT, hinit->pool->log, 0, "%ui: %ui %ui \"%V\"", size, key, test[key], &names[n].key); #endif if (test[key] > (u_short) bucket_size) { goto next; } } 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; test[key] = (u_short) (test[key] + NGX_HASH_ELT_SIZE(&names[n])); } 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->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; }