Mercurial > hg > nginx
view src/http/modules/ngx_http_mirror_module.c @ 7507:ea05113adbdb
Range filter: fixed loss of incoming chain links.
Filters are not allowed to change incoming chain links, and should allocate
their own links if any modifications are needed. Nevertheless
ngx_http_range_singlepart_body() modified incoming chain links in some
cases, notably at the end of the requested range.
No problems caused by this are currently known, mostly because of
limited number of possible modifications and the position of the range
body filter in the filter chain. Though this behaviour is clearly incorrect
and tests demonstrate that it can at least cause some proxy buffers being
lost when using proxy_force_ranges, leading to less effective handling
of responses.
Fix is to always allocate new chain links in ngx_http_range_singlepart_body().
Links are explicitly freed to ensure constant memory usage with long-lived
requests.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 13 May 2019 22:44:02 +0300 |
parents | 230d16d35ebc |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_array_t *mirror; ngx_flag_t request_body; } ngx_http_mirror_loc_conf_t; typedef struct { ngx_int_t status; } ngx_http_mirror_ctx_t; static ngx_int_t ngx_http_mirror_handler(ngx_http_request_t *r); static void ngx_http_mirror_body_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_mirror_handler_internal(ngx_http_request_t *r); static void *ngx_http_mirror_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_mirror_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static char *ngx_http_mirror(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_int_t ngx_http_mirror_init(ngx_conf_t *cf); static ngx_command_t ngx_http_mirror_commands[] = { { ngx_string("mirror"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_mirror, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("mirror_request_body"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_mirror_loc_conf_t, request_body), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_mirror_module_ctx = { NULL, /* preconfiguration */ ngx_http_mirror_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_mirror_create_loc_conf, /* create location configuration */ ngx_http_mirror_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_mirror_module = { NGX_MODULE_V1, &ngx_http_mirror_module_ctx, /* module context */ ngx_http_mirror_commands, /* module directives */ NGX_HTTP_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_http_mirror_handler(ngx_http_request_t *r) { ngx_int_t rc; ngx_http_mirror_ctx_t *ctx; ngx_http_mirror_loc_conf_t *mlcf; if (r != r->main) { return NGX_DECLINED; } mlcf = ngx_http_get_module_loc_conf(r, ngx_http_mirror_module); if (mlcf->mirror == NULL) { return NGX_DECLINED; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "mirror handler"); if (mlcf->request_body) { ctx = ngx_http_get_module_ctx(r, ngx_http_mirror_module); if (ctx) { return ctx->status; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_mirror_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ctx->status = NGX_DONE; ngx_http_set_ctx(r, ctx, ngx_http_mirror_module); rc = ngx_http_read_client_request_body(r, ngx_http_mirror_body_handler); if (rc >= NGX_HTTP_SPECIAL_RESPONSE) { return rc; } ngx_http_finalize_request(r, NGX_DONE); return NGX_DONE; } return ngx_http_mirror_handler_internal(r); } static void ngx_http_mirror_body_handler(ngx_http_request_t *r) { ngx_http_mirror_ctx_t *ctx; ctx = ngx_http_get_module_ctx(r, ngx_http_mirror_module); ctx->status = ngx_http_mirror_handler_internal(r); r->preserve_body = 1; r->write_event_handler = ngx_http_core_run_phases; ngx_http_core_run_phases(r); } static ngx_int_t ngx_http_mirror_handler_internal(ngx_http_request_t *r) { ngx_str_t *name; ngx_uint_t i; ngx_http_request_t *sr; ngx_http_mirror_loc_conf_t *mlcf; mlcf = ngx_http_get_module_loc_conf(r, ngx_http_mirror_module); name = mlcf->mirror->elts; for (i = 0; i < mlcf->mirror->nelts; i++) { if (ngx_http_subrequest(r, &name[i], &r->args, &sr, NULL, NGX_HTTP_SUBREQUEST_BACKGROUND) != NGX_OK) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } sr->header_only = 1; sr->method = r->method; sr->method_name = r->method_name; } return NGX_DECLINED; } static void * ngx_http_mirror_create_loc_conf(ngx_conf_t *cf) { ngx_http_mirror_loc_conf_t *mlcf; mlcf = ngx_pcalloc(cf->pool, sizeof(ngx_http_mirror_loc_conf_t)); if (mlcf == NULL) { return NULL; } mlcf->mirror = NGX_CONF_UNSET_PTR; mlcf->request_body = NGX_CONF_UNSET; return mlcf; } static char * ngx_http_mirror_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_mirror_loc_conf_t *prev = parent; ngx_http_mirror_loc_conf_t *conf = child; ngx_conf_merge_ptr_value(conf->mirror, prev->mirror, NULL); ngx_conf_merge_value(conf->request_body, prev->request_body, 1); return NGX_CONF_OK; } static char * ngx_http_mirror(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_mirror_loc_conf_t *mlcf = conf; ngx_str_t *value, *s; value = cf->args->elts; if (ngx_strcmp(value[1].data, "off") == 0) { if (mlcf->mirror != NGX_CONF_UNSET_PTR) { return "is duplicate"; } mlcf->mirror = NULL; return NGX_CONF_OK; } if (mlcf->mirror == NULL) { return "is duplicate"; } if (mlcf->mirror == NGX_CONF_UNSET_PTR) { mlcf->mirror = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t)); if (mlcf->mirror == NULL) { return NGX_CONF_ERROR; } } s = ngx_array_push(mlcf->mirror); if (s == NULL) { return NGX_CONF_ERROR; } *s = value[1]; return NGX_CONF_OK; } static ngx_int_t ngx_http_mirror_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_PRECONTENT_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_mirror_handler; return NGX_OK; }