Mercurial > hg > nginx
view src/http/ngx_http.h @ 6806:75dbab4ea930
Events: improved error event handling for UDP sockets.
Normally, the epoll module calls the read and write handlers depending
on whether EPOLLIN and EPOLLOUT are reported by epoll_wait(). No error
processing is done in the module, the handlers are expected to get an
error when doing I/O.
If an error event is reported without EPOLLIN and EPOLLOUT, the module
set both EPOLLIN and EPOLLOUT to ensure the error event is handled at
least in one active handler.
This works well unless the error is delivered along with only one of
EPOLLIN or EPOLLOUT, and the corresponding handler does not do any I/O.
For example, it happened when getting EPOLLERR|EPOLLOUT from
epoll_wait() upon receiving "ICMP port unreachable" while proxying UDP.
As the write handler had nothing to send it was not able to detect and
log an error, and did not switch to the next upstream.
The fix is to unconditionally set EPOLLIN and EPOLLOUT in case of an
error event. In the aforementioned case, this causes the read handler
to be called which does recv() and detects an error.
In addition to the epoll module, analogous changes were made in
devpoll/eventport/poll.
author | Dmitry Volyntsev <xeioex@nginx.com> |
---|---|
date | Mon, 21 Nov 2016 16:03:42 +0300 |
parents | bdf64ae3376b |
children | be2af41d3620 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HTTP_H_INCLUDED_ #define _NGX_HTTP_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> typedef struct ngx_http_request_s ngx_http_request_t; typedef struct ngx_http_upstream_s ngx_http_upstream_t; typedef struct ngx_http_cache_s ngx_http_cache_t; typedef struct ngx_http_file_cache_s ngx_http_file_cache_t; typedef struct ngx_http_log_ctx_s ngx_http_log_ctx_t; typedef struct ngx_http_chunked_s ngx_http_chunked_t; typedef struct ngx_http_v2_stream_s ngx_http_v2_stream_t; typedef ngx_int_t (*ngx_http_header_handler_pt)(ngx_http_request_t *r, ngx_table_elt_t *h, ngx_uint_t offset); typedef u_char *(*ngx_http_log_handler_pt)(ngx_http_request_t *r, ngx_http_request_t *sr, u_char *buf, size_t len); #include <ngx_http_variables.h> #include <ngx_http_config.h> #include <ngx_http_request.h> #include <ngx_http_script.h> #include <ngx_http_upstream.h> #include <ngx_http_upstream_round_robin.h> #include <ngx_http_core_module.h> #if (NGX_HTTP_V2) #include <ngx_http_v2.h> #endif #if (NGX_HTTP_CACHE) #include <ngx_http_cache.h> #endif #if (NGX_HTTP_SSI) #include <ngx_http_ssi_filter_module.h> #endif #if (NGX_HTTP_SSL) #include <ngx_http_ssl_module.h> #endif struct ngx_http_log_ctx_s { ngx_connection_t *connection; ngx_http_request_t *request; ngx_http_request_t *current_request; }; struct ngx_http_chunked_s { ngx_uint_t state; off_t size; off_t length; }; typedef struct { ngx_uint_t http_version; ngx_uint_t code; ngx_uint_t count; u_char *start; u_char *end; } ngx_http_status_t; #define ngx_http_get_module_ctx(r, module) (r)->ctx[module.ctx_index] #define ngx_http_set_ctx(r, c, module) r->ctx[module.ctx_index] = c; ngx_int_t ngx_http_add_location(ngx_conf_t *cf, ngx_queue_t **locations, ngx_http_core_loc_conf_t *clcf); ngx_int_t ngx_http_add_listen(ngx_conf_t *cf, ngx_http_core_srv_conf_t *cscf, ngx_http_listen_opt_t *lsopt); void ngx_http_init_connection(ngx_connection_t *c); void ngx_http_close_connection(ngx_connection_t *c); #if (NGX_HTTP_SSL && defined SSL_CTRL_SET_TLSEXT_HOSTNAME) int ngx_http_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg); #endif ngx_int_t ngx_http_parse_request_line(ngx_http_request_t *r, ngx_buf_t *b); ngx_int_t ngx_http_parse_uri(ngx_http_request_t *r); ngx_int_t ngx_http_parse_complex_uri(ngx_http_request_t *r, ngx_uint_t merge_slashes); ngx_int_t ngx_http_parse_status_line(ngx_http_request_t *r, ngx_buf_t *b, ngx_http_status_t *status); ngx_int_t ngx_http_parse_unsafe_uri(ngx_http_request_t *r, ngx_str_t *uri, ngx_str_t *args, ngx_uint_t *flags); ngx_int_t ngx_http_parse_header_line(ngx_http_request_t *r, ngx_buf_t *b, ngx_uint_t allow_underscores); ngx_int_t ngx_http_parse_multi_header_lines(ngx_array_t *headers, ngx_str_t *name, ngx_str_t *value); ngx_int_t ngx_http_parse_set_cookie_lines(ngx_array_t *headers, ngx_str_t *name, ngx_str_t *value); ngx_int_t ngx_http_arg(ngx_http_request_t *r, u_char *name, size_t len, ngx_str_t *value); void ngx_http_split_args(ngx_http_request_t *r, ngx_str_t *uri, ngx_str_t *args); ngx_int_t ngx_http_parse_chunked(ngx_http_request_t *r, ngx_buf_t *b, ngx_http_chunked_t *ctx); ngx_http_request_t *ngx_http_create_request(ngx_connection_t *c); ngx_int_t ngx_http_process_request_uri(ngx_http_request_t *r); ngx_int_t ngx_http_process_request_header(ngx_http_request_t *r); void ngx_http_process_request(ngx_http_request_t *r); void ngx_http_update_location_config(ngx_http_request_t *r); void ngx_http_handler(ngx_http_request_t *r); void ngx_http_run_posted_requests(ngx_connection_t *c); ngx_int_t ngx_http_post_request(ngx_http_request_t *r, ngx_http_posted_request_t *pr); void ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc); void ngx_http_free_request(ngx_http_request_t *r, ngx_int_t rc); void ngx_http_empty_handler(ngx_event_t *wev); void ngx_http_request_empty_handler(ngx_http_request_t *r); #define NGX_HTTP_LAST 1 #define NGX_HTTP_FLUSH 2 ngx_int_t ngx_http_send_special(ngx_http_request_t *r, ngx_uint_t flags); ngx_int_t ngx_http_read_client_request_body(ngx_http_request_t *r, ngx_http_client_body_handler_pt post_handler); ngx_int_t ngx_http_read_unbuffered_request_body(ngx_http_request_t *r); ngx_int_t ngx_http_send_header(ngx_http_request_t *r); ngx_int_t ngx_http_special_response_handler(ngx_http_request_t *r, ngx_int_t error); ngx_int_t ngx_http_filter_finalize_request(ngx_http_request_t *r, ngx_module_t *m, ngx_int_t error); void ngx_http_clean_header(ngx_http_request_t *r); ngx_int_t ngx_http_discard_request_body(ngx_http_request_t *r); void ngx_http_discarded_request_body_handler(ngx_http_request_t *r); void ngx_http_block_reading(ngx_http_request_t *r); void ngx_http_test_reading(ngx_http_request_t *r); char *ngx_http_types_slot(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); char *ngx_http_merge_types(ngx_conf_t *cf, ngx_array_t **keys, ngx_hash_t *types_hash, ngx_array_t **prev_keys, ngx_hash_t *prev_types_hash, ngx_str_t *default_types); ngx_int_t ngx_http_set_default_types(ngx_conf_t *cf, ngx_array_t **types, ngx_str_t *default_type); #if (NGX_HTTP_DEGRADATION) ngx_uint_t ngx_http_degraded(ngx_http_request_t *); #endif extern ngx_module_t ngx_http_module; extern ngx_str_t ngx_http_html_default_types[]; extern ngx_http_output_header_filter_pt ngx_http_top_header_filter; extern ngx_http_output_body_filter_pt ngx_http_top_body_filter; extern ngx_http_request_body_filter_pt ngx_http_top_request_body_filter; #endif /* _NGX_HTTP_H_INCLUDED_ */