Mercurial > hg > nginx
view src/http/modules/ngx_http_auth_request_module.c @ 9300:5be23505292b default tip
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +0300 |
parents | 8272c823a7d0 |
children |
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/* * Copyright (C) Maxim Dounin * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_str_t uri; ngx_array_t *vars; } ngx_http_auth_request_conf_t; typedef struct { ngx_uint_t done; ngx_uint_t status; ngx_http_request_t *subrequest; } ngx_http_auth_request_ctx_t; typedef struct { ngx_int_t index; ngx_http_complex_value_t value; ngx_http_set_variable_pt set_handler; } ngx_http_auth_request_variable_t; static ngx_int_t ngx_http_auth_request_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_auth_request_done(ngx_http_request_t *r, void *data, ngx_int_t rc); static ngx_int_t ngx_http_auth_request_set_variables(ngx_http_request_t *r, ngx_http_auth_request_conf_t *arcf, ngx_http_auth_request_ctx_t *ctx); static ngx_int_t ngx_http_auth_request_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static void *ngx_http_auth_request_create_conf(ngx_conf_t *cf); static char *ngx_http_auth_request_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_auth_request_init(ngx_conf_t *cf); static char *ngx_http_auth_request(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_auth_request_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_auth_request_commands[] = { { ngx_string("auth_request"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_auth_request, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("auth_request_set"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE2, ngx_http_auth_request_set, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_auth_request_module_ctx = { NULL, /* preconfiguration */ ngx_http_auth_request_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_auth_request_create_conf, /* create location configuration */ ngx_http_auth_request_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_auth_request_module = { NGX_MODULE_V1, &ngx_http_auth_request_module_ctx, /* module context */ ngx_http_auth_request_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_auth_request_handler(ngx_http_request_t *r) { ngx_table_elt_t *h, *ho, **ph; ngx_http_request_t *sr; ngx_http_post_subrequest_t *ps; ngx_http_auth_request_ctx_t *ctx; ngx_http_auth_request_conf_t *arcf; arcf = ngx_http_get_module_loc_conf(r, ngx_http_auth_request_module); if (arcf->uri.len == 0) { return NGX_DECLINED; } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request handler"); ctx = ngx_http_get_module_ctx(r, ngx_http_auth_request_module); if (ctx != NULL) { if (!ctx->done) { return NGX_AGAIN; } /* * as soon as we are done - explicitly set variables to make * sure they will be available after internal redirects */ if (ngx_http_auth_request_set_variables(r, arcf, ctx) != NGX_OK) { return NGX_ERROR; } /* return appropriate status */ if (ctx->status == NGX_HTTP_FORBIDDEN) { return ctx->status; } if (ctx->status == NGX_HTTP_UNAUTHORIZED) { sr = ctx->subrequest; h = sr->headers_out.www_authenticate; if (!h && sr->upstream) { h = sr->upstream->headers_in.www_authenticate; } ph = &r->headers_out.www_authenticate; while (h) { ho = ngx_list_push(&r->headers_out.headers); if (ho == NULL) { return NGX_ERROR; } *ho = *h; ho->next = NULL; *ph = ho; ph = &ho->next; h = h->next; } return ctx->status; } if (ctx->status >= NGX_HTTP_OK && ctx->status < NGX_HTTP_SPECIAL_RESPONSE) { return NGX_OK; } ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "auth request unexpected status: %ui", ctx->status); return NGX_HTTP_INTERNAL_SERVER_ERROR; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_auth_request_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ps = ngx_palloc(r->pool, sizeof(ngx_http_post_subrequest_t)); if (ps == NULL) { return NGX_ERROR; } ps->handler = ngx_http_auth_request_done; ps->data = ctx; if (ngx_http_subrequest(r, &arcf->uri, NULL, &sr, ps, NGX_HTTP_SUBREQUEST_WAITED) != NGX_OK) { return NGX_ERROR; } /* * allocate fake request body to avoid attempts to read it and to make * sure real body file (if already read) won't be closed by upstream */ sr->request_body = ngx_pcalloc(r->pool, sizeof(ngx_http_request_body_t)); if (sr->request_body == NULL) { return NGX_ERROR; } sr->header_only = 1; ctx->subrequest = sr; ngx_http_set_ctx(r, ctx, ngx_http_auth_request_module); return NGX_AGAIN; } static ngx_int_t ngx_http_auth_request_done(ngx_http_request_t *r, void *data, ngx_int_t rc) { ngx_http_auth_request_ctx_t *ctx = data; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request done s:%ui", r->headers_out.status); ctx->done = 1; ctx->status = r->headers_out.status; return rc; } static ngx_int_t ngx_http_auth_request_set_variables(ngx_http_request_t *r, ngx_http_auth_request_conf_t *arcf, ngx_http_auth_request_ctx_t *ctx) { ngx_str_t val; ngx_http_variable_t *v; ngx_http_variable_value_t *vv; ngx_http_auth_request_variable_t *av, *last; ngx_http_core_main_conf_t *cmcf; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request set variables"); if (arcf->vars == NULL) { return NGX_OK; } cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module); v = cmcf->variables.elts; av = arcf->vars->elts; last = av + arcf->vars->nelts; while (av < last) { /* * explicitly set new value to make sure it will be available after * internal redirects */ vv = &r->variables[av->index]; if (ngx_http_complex_value(ctx->subrequest, &av->value, &val) != NGX_OK) { return NGX_ERROR; } vv->valid = 1; vv->not_found = 0; vv->data = val.data; vv->len = val.len; if (av->set_handler) { /* * set_handler only available in cmcf->variables_keys, so we store * it explicitly */ av->set_handler(r, vv, v[av->index].data); } av++; } return NGX_OK; } static ngx_int_t ngx_http_auth_request_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "auth request variable"); v->not_found = 1; return NGX_OK; } static void * ngx_http_auth_request_create_conf(ngx_conf_t *cf) { ngx_http_auth_request_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_auth_request_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->uri = { 0, NULL }; */ conf->vars = NGX_CONF_UNSET_PTR; return conf; } static char * ngx_http_auth_request_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_auth_request_conf_t *prev = parent; ngx_http_auth_request_conf_t *conf = child; ngx_conf_merge_str_value(conf->uri, prev->uri, ""); ngx_conf_merge_ptr_value(conf->vars, prev->vars, NULL); return NGX_CONF_OK; } static ngx_int_t ngx_http_auth_request_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_ACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_auth_request_handler; return NGX_OK; } static char * ngx_http_auth_request(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_auth_request_conf_t *arcf = conf; ngx_str_t *value; if (arcf->uri.data != NULL) { return "is duplicate"; } value = cf->args->elts; if (ngx_strcmp(value[1].data, "off") == 0) { arcf->uri.len = 0; arcf->uri.data = (u_char *) ""; return NGX_CONF_OK; } arcf->uri = value[1]; return NGX_CONF_OK; } static char * ngx_http_auth_request_set(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_auth_request_conf_t *arcf = conf; ngx_str_t *value; ngx_http_variable_t *v; ngx_http_auth_request_variable_t *av; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; if (value[1].data[0] != '$') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid variable name \"%V\"", &value[1]); return NGX_CONF_ERROR; } value[1].len--; value[1].data++; if (arcf->vars == NGX_CONF_UNSET_PTR) { arcf->vars = ngx_array_create(cf->pool, 1, sizeof(ngx_http_auth_request_variable_t)); if (arcf->vars == NULL) { return NGX_CONF_ERROR; } } av = ngx_array_push(arcf->vars); if (av == NULL) { return NGX_CONF_ERROR; } v = ngx_http_add_variable(cf, &value[1], NGX_HTTP_VAR_CHANGEABLE); if (v == NULL) { return NGX_CONF_ERROR; } av->index = ngx_http_get_variable_index(cf, &value[1]); if (av->index == NGX_ERROR) { return NGX_CONF_ERROR; } if (v->get_handler == NULL) { v->get_handler = ngx_http_auth_request_variable; v->data = (uintptr_t) av; } av->set_handler = v->set_handler; ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[2]; ccv.complex_value = &av->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } return NGX_CONF_OK; }