view src/core/ngx_regex.h @ 8018:5119c8150478

Fixed runtime handling of systems without EPOLLRDHUP support. In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP support in the kernel (but with EPOLLRDHUP in headers) was broken. Before the change, rev->available was never set to 0 unless ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP introduced in 6536:f7849bfb6d21 succeeded). After the change, rev->available might reach 0 on systems without runtime EPOLLRDHUP support, stopping further reading in ngx_readv_chain() and ngx_unix_recv(). And, if EOF happened to be already reported along with the last event, it is not reported again by epoll_wait(), leading to connection hangs and timeouts on such systems. This affects Linux kernels before 2.6.17 if nginx was compiled with newer headers, and, more importantly, emulation layers, such as DigitalOcean's App Platform's / gVisor's epoll emulation layer. Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author Marcus Ball <marcus.ball@live.com>
date Mon, 30 May 2022 02:38:07 +0300
parents d07456044b61
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_REGEX_H_INCLUDED_
#define _NGX_REGEX_H_INCLUDED_


#include <ngx_config.h>
#include <ngx_core.h>


#if (NGX_PCRE2)

#define PCRE2_CODE_UNIT_WIDTH  8
#include <pcre2.h>

#define NGX_REGEX_NO_MATCHED   PCRE2_ERROR_NOMATCH   /* -1 */

typedef pcre2_code  ngx_regex_t;

#else

#include <pcre.h>

#define NGX_REGEX_NO_MATCHED   PCRE_ERROR_NOMATCH    /* -1 */

typedef struct {
    pcre        *code;
    pcre_extra  *extra;
} ngx_regex_t;

#endif


#define NGX_REGEX_CASELESS     0x00000001
#define NGX_REGEX_MULTILINE    0x00000002


typedef struct {
    ngx_str_t     pattern;
    ngx_pool_t   *pool;
    ngx_uint_t    options;

    ngx_regex_t  *regex;
    int           captures;
    int           named_captures;
    int           name_size;
    u_char       *names;
    ngx_str_t     err;
} ngx_regex_compile_t;


typedef struct {
    ngx_regex_t  *regex;
    u_char       *name;
} ngx_regex_elt_t;


void ngx_regex_init(void);
ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc);

ngx_int_t ngx_regex_exec(ngx_regex_t *re, ngx_str_t *s, int *captures,
    ngx_uint_t size);

#if (NGX_PCRE2)
#define ngx_regex_exec_n       "pcre2_match()"
#else
#define ngx_regex_exec_n       "pcre_exec()"
#endif

ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log);


#endif /* _NGX_REGEX_H_INCLUDED_ */