Mercurial > hg > nginx
view src/http/modules/ngx_http_mirror_module.c @ 7674:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +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; }