Mercurial > hg > nginx-quic
view src/stream/ngx_stream_return_module.c @ 7440:6d4bc025c5a7
Prevented scheduling events on a shared connection.
A shared connection does not own its file descriptor, which means that
ngx_handle_read_event/ngx_handle_write_event calls should do nothing for it.
Currently the c->shared flag is checked in several places in the stream proxy
module prior to calling these functions. However it was not done everywhere.
Missing checks could lead to calling
ngx_handle_read_event/ngx_handle_write_event on shared connections.
The problem manifested itself when using proxy_upload_rate and resulted in
either duplicate file descriptor error (e.g. with epoll) or incorrect further
udp packet processing (e.g. with kqueue).
The fix is to set and reset the event active flag in a way that prevents
ngx_handle_read_event/ngx_handle_write_event from scheduling socket events.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 14 Jan 2019 20:36:23 +0300 |
parents | 56fc55e32f23 |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_stream_complex_value_t text; } ngx_stream_return_srv_conf_t; typedef struct { ngx_chain_t *out; } ngx_stream_return_ctx_t; static void ngx_stream_return_handler(ngx_stream_session_t *s); static void ngx_stream_return_write_handler(ngx_event_t *ev); static void *ngx_stream_return_create_srv_conf(ngx_conf_t *cf); static char *ngx_stream_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_stream_return_commands[] = { { ngx_string("return"), NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1, ngx_stream_return, NGX_STREAM_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_return_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_stream_return_create_srv_conf, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_return_module = { NGX_MODULE_V1, &ngx_stream_return_module_ctx, /* module context */ ngx_stream_return_commands, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static void ngx_stream_return_handler(ngx_stream_session_t *s) { ngx_str_t text; ngx_buf_t *b; ngx_connection_t *c; ngx_stream_return_ctx_t *ctx; ngx_stream_return_srv_conf_t *rscf; c = s->connection; c->log->action = "returning text"; rscf = ngx_stream_get_module_srv_conf(s, ngx_stream_return_module); if (ngx_stream_complex_value(s, &rscf->text, &text) != NGX_OK) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } ngx_log_debug1(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream return text: \"%V\"", &text); if (text.len == 0) { ngx_stream_finalize_session(s, NGX_STREAM_OK); return; } ctx = ngx_pcalloc(c->pool, sizeof(ngx_stream_return_ctx_t)); if (ctx == NULL) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } ngx_stream_set_ctx(s, ctx, ngx_stream_return_module); b = ngx_calloc_buf(c->pool); if (b == NULL) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } b->memory = 1; b->pos = text.data; b->last = text.data + text.len; b->last_buf = 1; ctx->out = ngx_alloc_chain_link(c->pool); if (ctx->out == NULL) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } ctx->out->buf = b; ctx->out->next = NULL; c->write->handler = ngx_stream_return_write_handler; ngx_stream_return_write_handler(c->write); } static void ngx_stream_return_write_handler(ngx_event_t *ev) { ngx_connection_t *c; ngx_stream_session_t *s; ngx_stream_return_ctx_t *ctx; c = ev->data; s = c->data; if (ev->timedout) { ngx_connection_error(c, NGX_ETIMEDOUT, "connection timed out"); ngx_stream_finalize_session(s, NGX_STREAM_OK); return; } ctx = ngx_stream_get_module_ctx(s, ngx_stream_return_module); if (ngx_stream_top_filter(s, ctx->out, 1) == NGX_ERROR) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } ctx->out = NULL; if (!c->buffered) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, c->log, 0, "stream return done sending"); ngx_stream_finalize_session(s, NGX_STREAM_OK); return; } if (ngx_handle_write_event(ev, 0) != NGX_OK) { ngx_stream_finalize_session(s, NGX_STREAM_INTERNAL_SERVER_ERROR); return; } ngx_add_timer(ev, 5000); } static void * ngx_stream_return_create_srv_conf(ngx_conf_t *cf) { ngx_stream_return_srv_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_return_srv_conf_t)); if (conf == NULL) { return NULL; } return conf; } static char * ngx_stream_return(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_return_srv_conf_t *rscf = conf; ngx_str_t *value; ngx_stream_core_srv_conf_t *cscf; ngx_stream_compile_complex_value_t ccv; if (rscf->text.value.data) { return "is duplicate"; } value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &rscf->text; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } cscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_core_module); cscf->handler = ngx_stream_return_handler; return NGX_CONF_OK; }