Mercurial > hg > nginx-quic
view src/stream/ngx_stream_set_module.c @ 8867:5119c8150478
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 | 45e9281c6c5b |
children |
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/* * Copyright (C) Pavel Pautov * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_int_t index; ngx_stream_set_variable_pt set_handler; uintptr_t data; ngx_stream_complex_value_t value; } ngx_stream_set_cmd_t; typedef struct { ngx_array_t commands; } ngx_stream_set_srv_conf_t; static ngx_int_t ngx_stream_set_handler(ngx_stream_session_t *s); static ngx_int_t ngx_stream_set_var(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_stream_set_init(ngx_conf_t *cf); static void *ngx_stream_set_create_srv_conf(ngx_conf_t *cf); static char *ngx_stream_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_stream_set_commands[] = { { ngx_string("set"), NGX_STREAM_SRV_CONF|NGX_CONF_TAKE2, ngx_stream_set, NGX_STREAM_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_set_module_ctx = { NULL, /* preconfiguration */ ngx_stream_set_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_stream_set_create_srv_conf, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_set_module = { NGX_MODULE_V1, &ngx_stream_set_module_ctx, /* module context */ ngx_stream_set_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 ngx_int_t ngx_stream_set_handler(ngx_stream_session_t *s) { ngx_str_t str; ngx_uint_t i; ngx_stream_set_cmd_t *cmds; ngx_stream_set_srv_conf_t *scf; ngx_stream_variable_value_t vv; scf = ngx_stream_get_module_srv_conf(s, ngx_stream_set_module); cmds = scf->commands.elts; vv = ngx_stream_variable_null_value; for (i = 0; i < scf->commands.nelts; i++) { if (ngx_stream_complex_value(s, &cmds[i].value, &str) != NGX_OK) { return NGX_ERROR; } if (cmds[i].set_handler != NULL) { vv.len = str.len; vv.data = str.data; cmds[i].set_handler(s, &vv, cmds[i].data); } else { s->variables[cmds[i].index].len = str.len; s->variables[cmds[i].index].valid = 1; s->variables[cmds[i].index].no_cacheable = 0; s->variables[cmds[i].index].not_found = 0; s->variables[cmds[i].index].data = str.data; } } return NGX_DECLINED; } static ngx_int_t ngx_stream_set_var(ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data) { *v = ngx_stream_variable_null_value; return NGX_OK; } static ngx_int_t ngx_stream_set_init(ngx_conf_t *cf) { ngx_stream_handler_pt *h; ngx_stream_core_main_conf_t *cmcf; cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module); h = ngx_array_push(&cmcf->phases[NGX_STREAM_PREACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_stream_set_handler; return NGX_OK; } static void * ngx_stream_set_create_srv_conf(ngx_conf_t *cf) { ngx_stream_set_srv_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_set_srv_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->commands = { NULL }; */ return conf; } static char * ngx_stream_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_set_srv_conf_t *scf = conf; ngx_str_t *args; ngx_int_t index; ngx_stream_set_cmd_t *set_cmd; ngx_stream_variable_t *v; ngx_stream_compile_complex_value_t ccv; args = cf->args->elts; if (args[1].data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &args[1]); return NGX_CONF_ERROR; } args[1].len--; args[1].data++; v = ngx_stream_add_variable(cf, &args[1], NGX_STREAM_VAR_CHANGEABLE|NGX_STREAM_VAR_WEAK); if (v == NULL) { return NGX_CONF_ERROR; } index = ngx_stream_get_variable_index(cf, &args[1]); if (index == NGX_ERROR) { return NGX_CONF_ERROR; } if (v->get_handler == NULL) { v->get_handler = ngx_stream_set_var; } if (scf->commands.elts == NULL) { if (ngx_array_init(&scf->commands, cf->pool, 1, sizeof(ngx_stream_set_cmd_t)) != NGX_OK) { return NGX_CONF_ERROR; } } set_cmd = ngx_array_push(&scf->commands); if (set_cmd == NULL) { return NGX_CONF_ERROR; } set_cmd->index = index; set_cmd->set_handler = v->set_handler; set_cmd->data = v->data; ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = cf; ccv.value = &args[2]; ccv.complex_value = &set_cmd->value; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; }