Mercurial > hg > nginx-quic
view src/core/ngx_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 | 3600bbfb43e3 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Maxim Dounin * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #define NGX_MAX_DYNAMIC_MODULES 128 static ngx_uint_t ngx_module_index(ngx_cycle_t *cycle); static ngx_uint_t ngx_module_ctx_index(ngx_cycle_t *cycle, ngx_uint_t type, ngx_uint_t index); ngx_uint_t ngx_max_module; static ngx_uint_t ngx_modules_n; ngx_int_t ngx_preinit_modules(void) { ngx_uint_t i; for (i = 0; ngx_modules[i]; i++) { ngx_modules[i]->index = i; ngx_modules[i]->name = ngx_module_names[i]; } ngx_modules_n = i; ngx_max_module = ngx_modules_n + NGX_MAX_DYNAMIC_MODULES; return NGX_OK; } ngx_int_t ngx_cycle_modules(ngx_cycle_t *cycle) { /* * create a list of modules to be used for this cycle, * copy static modules to it */ cycle->modules = ngx_pcalloc(cycle->pool, (ngx_max_module + 1) * sizeof(ngx_module_t *)); if (cycle->modules == NULL) { return NGX_ERROR; } ngx_memcpy(cycle->modules, ngx_modules, ngx_modules_n * sizeof(ngx_module_t *)); cycle->modules_n = ngx_modules_n; return NGX_OK; } ngx_int_t ngx_init_modules(ngx_cycle_t *cycle) { ngx_uint_t i; for (i = 0; cycle->modules[i]; i++) { if (cycle->modules[i]->init_module) { if (cycle->modules[i]->init_module(cycle) != NGX_OK) { return NGX_ERROR; } } } return NGX_OK; } ngx_int_t ngx_count_modules(ngx_cycle_t *cycle, ngx_uint_t type) { ngx_uint_t i, next, max; ngx_module_t *module; next = 0; max = 0; /* count appropriate modules, set up their indices */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index != NGX_MODULE_UNSET_INDEX) { /* if ctx_index was assigned, preserve it */ if (module->ctx_index > max) { max = module->ctx_index; } if (module->ctx_index == next) { next++; } continue; } /* search for some free index */ module->ctx_index = ngx_module_ctx_index(cycle, type, next); if (module->ctx_index > max) { max = module->ctx_index; } next = module->ctx_index + 1; } /* * make sure the number returned is big enough for previous * cycle as well, else there will be problems if the number * will be stored in a global variable (as it's used to be) * and we'll have to roll back to the previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index > max) { max = module->ctx_index; } } } /* prevent loading of additional modules */ cycle->modules_used = 1; return max + 1; } ngx_int_t ngx_add_module(ngx_conf_t *cf, ngx_str_t *file, ngx_module_t *module, char **order) { void *rv; ngx_uint_t i, m, before; ngx_core_module_t *core_module; if (cf->cycle->modules_n >= ngx_max_module) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "too many modules loaded"); return NGX_ERROR; } if (module->version != nginx_version) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%V\" version %ui instead of %ui", file, module->version, (ngx_uint_t) nginx_version); return NGX_ERROR; } if (ngx_strcmp(module->signature, NGX_MODULE_SIGNATURE) != 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%V\" is not binary compatible", file); return NGX_ERROR; } for (m = 0; cf->cycle->modules[m]; m++) { if (ngx_strcmp(cf->cycle->modules[m]->name, module->name) == 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "module \"%s\" is already loaded", module->name); return NGX_ERROR; } } /* * if the module wasn't previously loaded, assign an index */ if (module->index == NGX_MODULE_UNSET_INDEX) { module->index = ngx_module_index(cf->cycle); if (module->index >= ngx_max_module) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "too many modules loaded"); return NGX_ERROR; } } /* * put the module into the cycle->modules array */ before = cf->cycle->modules_n; if (order) { for (i = 0; order[i]; i++) { if (ngx_strcmp(order[i], module->name) == 0) { i++; break; } } for ( /* void */ ; order[i]; i++) { #if 0 ngx_log_debug2(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s before %s", module->name, order[i]); #endif for (m = 0; m < before; m++) { if (ngx_strcmp(cf->cycle->modules[m]->name, order[i]) == 0) { ngx_log_debug3(NGX_LOG_DEBUG_CORE, cf->log, 0, "module: %s before %s:%i", module->name, order[i], m); before = m; break; } } } } /* put the module before modules[before] */ if (before != cf->cycle->modules_n) { ngx_memmove(&cf->cycle->modules[before + 1], &cf->cycle->modules[before], (cf->cycle->modules_n - before) * sizeof(ngx_module_t *)); } cf->cycle->modules[before] = module; cf->cycle->modules_n++; if (module->type == NGX_CORE_MODULE) { /* * we are smart enough to initialize core modules; * other modules are expected to be loaded before * initialization - e.g., http modules must be loaded * before http{} block */ core_module = module->ctx; if (core_module->create_conf) { rv = core_module->create_conf(cf->cycle); if (rv == NULL) { return NGX_ERROR; } cf->cycle->conf_ctx[module->index] = rv; } } return NGX_OK; } static ngx_uint_t ngx_module_index(ngx_cycle_t *cycle) { ngx_uint_t i, index; ngx_module_t *module; index = 0; again: /* find an unused index */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->index == index) { index++; goto again; } } /* check previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->index == index) { index++; goto again; } } } return index; } static ngx_uint_t ngx_module_ctx_index(ngx_cycle_t *cycle, ngx_uint_t type, ngx_uint_t index) { ngx_uint_t i; ngx_module_t *module; again: /* find an unused ctx_index */ for (i = 0; cycle->modules[i]; i++) { module = cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index == index) { index++; goto again; } } /* check previous cycle */ if (cycle->old_cycle && cycle->old_cycle->modules) { for (i = 0; cycle->old_cycle->modules[i]; i++) { module = cycle->old_cycle->modules[i]; if (module->type != type) { continue; } if (module->ctx_index == index) { index++; goto again; } } } return index; }