Mercurial > hg > nginx
view src/core/ngx_regex.c @ 8045:aa28c802409f
Resolver: make TCP write timer event cancelable.
Similar to 70e65bf8dfd7, the change is made to ensure that the ability to
cancel resolver tasks is fully controlled by the caller. As mentioned in the
referenced commit, it is safe to make this timer cancelable because resolve
tasks can have their own timeouts that are not cancelable.
The scenario where this may become a problem is a periodic background resolve
task (not tied to a specific request or a client connection), which receives a
response with short TTL, large enough to warrant fallback to a TCP query.
With each event loop wakeup, we either have a previously set write timer
instance or schedule a new one. The non-cancelable write timer can delay or
block graceful shutdown of a worker even if the ngx_resolver_ctx_t->cancelable
flag is set by the API user, and there are no other tasks or connections.
We use the resolver API in this way to maintain the list of upstream server
addresses specified with the 'resolve' parameter, and there could be third-party
modules implementing similar logic.
author | Aleksei Bavshin <a.bavshin@f5.com> |
---|---|
date | Wed, 01 Jun 2022 20:17:23 -0700 |
parents | d07456044b61 |
children | 77d5c662f3d9 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> typedef struct { ngx_flag_t pcre_jit; ngx_list_t *studies; } ngx_regex_conf_t; static ngx_inline void ngx_regex_malloc_init(ngx_pool_t *pool); static ngx_inline void ngx_regex_malloc_done(void); #if (NGX_PCRE2) static void * ngx_libc_cdecl ngx_regex_malloc(size_t size, void *data); static void ngx_libc_cdecl ngx_regex_free(void *p, void *data); #else static void * ngx_libc_cdecl ngx_regex_malloc(size_t size); static void ngx_libc_cdecl ngx_regex_free(void *p); #endif static void ngx_regex_cleanup(void *data); static ngx_int_t ngx_regex_module_init(ngx_cycle_t *cycle); static void *ngx_regex_create_conf(ngx_cycle_t *cycle); static char *ngx_regex_init_conf(ngx_cycle_t *cycle, void *conf); static char *ngx_regex_pcre_jit(ngx_conf_t *cf, void *post, void *data); static ngx_conf_post_t ngx_regex_pcre_jit_post = { ngx_regex_pcre_jit }; static ngx_command_t ngx_regex_commands[] = { { ngx_string("pcre_jit"), NGX_MAIN_CONF|NGX_DIRECT_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, 0, offsetof(ngx_regex_conf_t, pcre_jit), &ngx_regex_pcre_jit_post }, ngx_null_command }; static ngx_core_module_t ngx_regex_module_ctx = { ngx_string("regex"), ngx_regex_create_conf, ngx_regex_init_conf }; ngx_module_t ngx_regex_module = { NGX_MODULE_V1, &ngx_regex_module_ctx, /* module context */ ngx_regex_commands, /* module directives */ NGX_CORE_MODULE, /* module type */ NULL, /* init master */ ngx_regex_module_init, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static ngx_pool_t *ngx_regex_pool; static ngx_list_t *ngx_regex_studies; static ngx_uint_t ngx_regex_direct_alloc; #if (NGX_PCRE2) static pcre2_compile_context *ngx_regex_compile_context; static pcre2_match_data *ngx_regex_match_data; static ngx_uint_t ngx_regex_match_data_size; #endif void ngx_regex_init(void) { #if !(NGX_PCRE2) pcre_malloc = ngx_regex_malloc; pcre_free = ngx_regex_free; #endif } static ngx_inline void ngx_regex_malloc_init(ngx_pool_t *pool) { ngx_regex_pool = pool; ngx_regex_direct_alloc = (pool == NULL) ? 1 : 0; } static ngx_inline void ngx_regex_malloc_done(void) { ngx_regex_pool = NULL; ngx_regex_direct_alloc = 0; } #if (NGX_PCRE2) ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc) { int n, errcode; char *p; u_char errstr[128]; size_t erroff; uint32_t options; pcre2_code *re; ngx_regex_elt_t *elt; pcre2_general_context *gctx; pcre2_compile_context *cctx; if (ngx_regex_compile_context == NULL) { /* * Allocate a compile context if not yet allocated. This uses * direct allocations from heap, so the result can be cached * even at runtime. */ ngx_regex_malloc_init(NULL); gctx = pcre2_general_context_create(ngx_regex_malloc, ngx_regex_free, NULL); if (gctx == NULL) { ngx_regex_malloc_done(); goto nomem; } cctx = pcre2_compile_context_create(gctx); if (cctx == NULL) { pcre2_general_context_free(gctx); ngx_regex_malloc_done(); goto nomem; } ngx_regex_compile_context = cctx; pcre2_general_context_free(gctx); ngx_regex_malloc_done(); } options = 0; if (rc->options & NGX_REGEX_CASELESS) { options |= PCRE2_CASELESS; } if (rc->options & NGX_REGEX_MULTILINE) { options |= PCRE2_MULTILINE; } if (rc->options & ~(NGX_REGEX_CASELESS|NGX_REGEX_MULTILINE)) { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "regex \"%V\" compilation failed: invalid options", &rc->pattern) - rc->err.data; return NGX_ERROR; } ngx_regex_malloc_init(rc->pool); re = pcre2_compile(rc->pattern.data, rc->pattern.len, options, &errcode, &erroff, ngx_regex_compile_context); /* ensure that there is no current pool */ ngx_regex_malloc_done(); if (re == NULL) { pcre2_get_error_message(errcode, errstr, 128); if ((size_t) erroff == rc->pattern.len) { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre2_compile() failed: %s in \"%V\"", errstr, &rc->pattern) - rc->err.data; } else { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre2_compile() failed: %s in \"%V\" at \"%s\"", errstr, &rc->pattern, rc->pattern.data + erroff) - rc->err.data; } return NGX_ERROR; } rc->regex = re; /* do not study at runtime */ if (ngx_regex_studies != NULL) { elt = ngx_list_push(ngx_regex_studies); if (elt == NULL) { goto nomem; } elt->regex = rc->regex; elt->name = rc->pattern.data; } n = pcre2_pattern_info(re, PCRE2_INFO_CAPTURECOUNT, &rc->captures); if (n < 0) { p = "pcre2_pattern_info(\"%V\", PCRE2_INFO_CAPTURECOUNT) failed: %d"; goto failed; } if (rc->captures == 0) { return NGX_OK; } n = pcre2_pattern_info(re, PCRE2_INFO_NAMECOUNT, &rc->named_captures); if (n < 0) { p = "pcre2_pattern_info(\"%V\", PCRE2_INFO_NAMECOUNT) failed: %d"; goto failed; } if (rc->named_captures == 0) { return NGX_OK; } n = pcre2_pattern_info(re, PCRE2_INFO_NAMEENTRYSIZE, &rc->name_size); if (n < 0) { p = "pcre2_pattern_info(\"%V\", PCRE2_INFO_NAMEENTRYSIZE) failed: %d"; goto failed; } n = pcre2_pattern_info(re, PCRE2_INFO_NAMETABLE, &rc->names); if (n < 0) { p = "pcre2_pattern_info(\"%V\", PCRE2_INFO_NAMETABLE) failed: %d"; goto failed; } return NGX_OK; failed: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, p, &rc->pattern, n) - rc->err.data; return NGX_ERROR; nomem: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "regex \"%V\" compilation failed: no memory", &rc->pattern) - rc->err.data; return NGX_ERROR; } #else ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc) { int n, erroff; char *p; pcre *re; const char *errstr; ngx_uint_t options; ngx_regex_elt_t *elt; options = 0; if (rc->options & NGX_REGEX_CASELESS) { options |= PCRE_CASELESS; } if (rc->options & NGX_REGEX_MULTILINE) { options |= PCRE_MULTILINE; } if (rc->options & ~(NGX_REGEX_CASELESS|NGX_REGEX_MULTILINE)) { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "regex \"%V\" compilation failed: invalid options", &rc->pattern) - rc->err.data; return NGX_ERROR; } ngx_regex_malloc_init(rc->pool); re = pcre_compile((const char *) rc->pattern.data, (int) options, &errstr, &erroff, NULL); /* ensure that there is no current pool */ ngx_regex_malloc_done(); if (re == NULL) { if ((size_t) erroff == rc->pattern.len) { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre_compile() failed: %s in \"%V\"", errstr, &rc->pattern) - rc->err.data; } else { rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "pcre_compile() failed: %s in \"%V\" at \"%s\"", errstr, &rc->pattern, rc->pattern.data + erroff) - rc->err.data; } return NGX_ERROR; } rc->regex = ngx_pcalloc(rc->pool, sizeof(ngx_regex_t)); if (rc->regex == NULL) { goto nomem; } rc->regex->code = re; /* do not study at runtime */ if (ngx_regex_studies != NULL) { elt = ngx_list_push(ngx_regex_studies); if (elt == NULL) { goto nomem; } elt->regex = rc->regex; elt->name = rc->pattern.data; } n = pcre_fullinfo(re, NULL, PCRE_INFO_CAPTURECOUNT, &rc->captures); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_CAPTURECOUNT) failed: %d"; goto failed; } if (rc->captures == 0) { return NGX_OK; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMECOUNT, &rc->named_captures); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMECOUNT) failed: %d"; goto failed; } if (rc->named_captures == 0) { return NGX_OK; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMEENTRYSIZE, &rc->name_size); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMEENTRYSIZE) failed: %d"; goto failed; } n = pcre_fullinfo(re, NULL, PCRE_INFO_NAMETABLE, &rc->names); if (n < 0) { p = "pcre_fullinfo(\"%V\", PCRE_INFO_NAMETABLE) failed: %d"; goto failed; } return NGX_OK; failed: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, p, &rc->pattern, n) - rc->err.data; return NGX_ERROR; nomem: rc->err.len = ngx_snprintf(rc->err.data, rc->err.len, "regex \"%V\" compilation failed: no memory", &rc->pattern) - rc->err.data; return NGX_ERROR; } #endif #if (NGX_PCRE2) ngx_int_t ngx_regex_exec(ngx_regex_t *re, ngx_str_t *s, int *captures, ngx_uint_t size) { size_t *ov; ngx_int_t rc; ngx_uint_t n, i; /* * The pcre2_match() function might allocate memory for backtracking * frames, typical allocations are from 40k and above. So the allocator * is configured to do direct allocations from heap during matching. */ ngx_regex_malloc_init(NULL); if (ngx_regex_match_data == NULL || size > ngx_regex_match_data_size) { /* * Allocate a match data if not yet allocated or smaller than * needed. */ if (ngx_regex_match_data) { pcre2_match_data_free(ngx_regex_match_data); } ngx_regex_match_data_size = size; ngx_regex_match_data = pcre2_match_data_create(size / 3, NULL); if (ngx_regex_match_data == NULL) { rc = PCRE2_ERROR_NOMEMORY; goto failed; } } rc = pcre2_match(re, s->data, s->len, 0, 0, ngx_regex_match_data, NULL); if (rc < 0) { goto failed; } n = pcre2_get_ovector_count(ngx_regex_match_data); ov = pcre2_get_ovector_pointer(ngx_regex_match_data); if (n > size / 3) { n = size / 3; } for (i = 0; i < n; i++) { captures[i * 2] = ov[i * 2]; captures[i * 2 + 1] = ov[i * 2 + 1]; } failed: ngx_regex_malloc_done(); return rc; } #else ngx_int_t ngx_regex_exec(ngx_regex_t *re, ngx_str_t *s, int *captures, ngx_uint_t size) { return pcre_exec(re->code, re->extra, (const char *) s->data, s->len, 0, 0, captures, size); } #endif ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log) { ngx_int_t n; ngx_uint_t i; ngx_regex_elt_t *re; re = a->elts; for (i = 0; i < a->nelts; i++) { n = ngx_regex_exec(re[i].regex, s, NULL, 0); if (n == NGX_REGEX_NO_MATCHED) { continue; } if (n < 0) { ngx_log_error(NGX_LOG_ALERT, log, 0, ngx_regex_exec_n " failed: %i on \"%V\" using \"%s\"", n, s, re[i].name); return NGX_ERROR; } /* match */ return NGX_OK; } return NGX_DECLINED; } #if (NGX_PCRE2) static void * ngx_libc_cdecl ngx_regex_malloc(size_t size, void *data) { if (ngx_regex_pool) { return ngx_palloc(ngx_regex_pool, size); } if (ngx_regex_direct_alloc) { return ngx_alloc(size, ngx_cycle->log); } return NULL; } static void ngx_libc_cdecl ngx_regex_free(void *p, void *data) { if (ngx_regex_direct_alloc) { ngx_free(p); } return; } #else static void * ngx_libc_cdecl ngx_regex_malloc(size_t size) { if (ngx_regex_pool) { return ngx_palloc(ngx_regex_pool, size); } return NULL; } static void ngx_libc_cdecl ngx_regex_free(void *p) { return; } #endif static void ngx_regex_cleanup(void *data) { #if (NGX_PCRE2 || NGX_HAVE_PCRE_JIT) ngx_regex_conf_t *rcf = data; ngx_uint_t i; ngx_list_part_t *part; ngx_regex_elt_t *elts; part = &rcf->studies->part; elts = part->elts; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; elts = part->elts; i = 0; } /* * The PCRE JIT compiler uses mmap for its executable codes, so we * have to explicitly call the pcre_free_study() function to free * this memory. In PCRE2, we call the pcre2_code_free() function * for the same reason. */ #if (NGX_PCRE2) pcre2_code_free(elts[i].regex); #else if (elts[i].regex->extra != NULL) { pcre_free_study(elts[i].regex->extra); } #endif } #endif /* * On configuration parsing errors ngx_regex_module_init() will not * be called. Make sure ngx_regex_studies is properly cleared anyway. */ ngx_regex_studies = NULL; #if (NGX_PCRE2) /* * Free compile context and match data. If needed at runtime by * the new cycle, these will be re-allocated. */ if (ngx_regex_compile_context) { pcre2_compile_context_free(ngx_regex_compile_context); ngx_regex_compile_context = NULL; } if (ngx_regex_match_data) { pcre2_match_data_free(ngx_regex_match_data); ngx_regex_match_data = NULL; ngx_regex_match_data_size = 0; } #endif } static ngx_int_t ngx_regex_module_init(ngx_cycle_t *cycle) { int opt; #if !(NGX_PCRE2) const char *errstr; #endif ngx_uint_t i; ngx_list_part_t *part; ngx_regex_elt_t *elts; ngx_regex_conf_t *rcf; opt = 0; rcf = (ngx_regex_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_regex_module); #if (NGX_PCRE2 || NGX_HAVE_PCRE_JIT) if (rcf->pcre_jit) { #if (NGX_PCRE2) opt = 1; #else opt = PCRE_STUDY_JIT_COMPILE; #endif } #endif ngx_regex_malloc_init(cycle->pool); part = &rcf->studies->part; elts = part->elts; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; elts = part->elts; i = 0; } #if (NGX_PCRE2) if (opt) { int n; n = pcre2_jit_compile(elts[i].regex, PCRE2_JIT_COMPLETE); if (n != 0) { ngx_log_error(NGX_LOG_INFO, cycle->log, 0, "pcre2_jit_compile() failed: %d in \"%s\", " "ignored", n, elts[i].name); } } #else elts[i].regex->extra = pcre_study(elts[i].regex->code, opt, &errstr); if (errstr != NULL) { ngx_log_error(NGX_LOG_ALERT, cycle->log, 0, "pcre_study() failed: %s in \"%s\"", errstr, elts[i].name); } #if (NGX_HAVE_PCRE_JIT) if (opt & PCRE_STUDY_JIT_COMPILE) { int jit, n; jit = 0; n = pcre_fullinfo(elts[i].regex->code, elts[i].regex->extra, PCRE_INFO_JIT, &jit); if (n != 0 || jit != 1) { ngx_log_error(NGX_LOG_INFO, cycle->log, 0, "JIT compiler does not support pattern: \"%s\"", elts[i].name); } } #endif #endif } ngx_regex_malloc_done(); ngx_regex_studies = NULL; #if (NGX_PCRE2) ngx_regex_compile_context = NULL; #endif return NGX_OK; } static void * ngx_regex_create_conf(ngx_cycle_t *cycle) { ngx_regex_conf_t *rcf; ngx_pool_cleanup_t *cln; rcf = ngx_pcalloc(cycle->pool, sizeof(ngx_regex_conf_t)); if (rcf == NULL) { return NULL; } rcf->pcre_jit = NGX_CONF_UNSET; cln = ngx_pool_cleanup_add(cycle->pool, 0); if (cln == NULL) { return NULL; } cln->handler = ngx_regex_cleanup; cln->data = rcf; rcf->studies = ngx_list_create(cycle->pool, 8, sizeof(ngx_regex_elt_t)); if (rcf->studies == NULL) { return NULL; } ngx_regex_studies = rcf->studies; return rcf; } static char * ngx_regex_init_conf(ngx_cycle_t *cycle, void *conf) { ngx_regex_conf_t *rcf = conf; ngx_conf_init_value(rcf->pcre_jit, 0); return NGX_CONF_OK; } static char * ngx_regex_pcre_jit(ngx_conf_t *cf, void *post, void *data) { ngx_flag_t *fp = data; if (*fp == 0) { return NGX_CONF_OK; } #if (NGX_PCRE2) { int r; uint32_t jit; jit = 0; r = pcre2_config(PCRE2_CONFIG_JIT, &jit); if (r != 0 || jit != 1) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "PCRE2 library does not support JIT"); *fp = 0; } } #elif (NGX_HAVE_PCRE_JIT) { int jit, r; jit = 0; r = pcre_config(PCRE_CONFIG_JIT, &jit); if (r != 0 || jit != 1) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "PCRE library does not support JIT"); *fp = 0; } } #else ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "nginx was built without PCRE JIT support"); *fp = 0; #endif return NGX_CONF_OK; }