Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_headers_filter_module.c @ 7514:319242d2ddc9
Upstream: background cache update before cache send (ticket #1782).
In case of filter finalization, essential request fields like r->uri,
r->args etc could be changed, which affected the cache update subrequest.
Also, after filter finalization r->cache could be set to NULL, leading to
null pointer dereference in ngx_http_upstream_cache_background_update().
The fix is to create background cache update subrequest before sending the
cached response.
Since initial introduction in 1aeaae6e9446 (1.11.10) background cache update
subrequest was created after sending the cached response because otherwise it
blocked the parent request output. In 9552758a786e (1.13.1) background
subrequests were introduced to eliminate the delay before sending the final
part of the cached response. This also made it possible to create the
background cache update subrequest before sending the response.
Note that creating the subrequest earlier does not change the fact that in case
of filter finalization the background cache update subrequest will likely not
have enough time to successfully update the cache entry. Filter finalization
leads to the main request termination as soon the current iteration of request
processing is complete.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Mon, 03 Jun 2019 20:33:26 +0300 |
parents | 6ba68ad8b24c |
children | ef6a3a99a81a |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct ngx_http_header_val_s ngx_http_header_val_t; typedef ngx_int_t (*ngx_http_set_header_pt)(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); typedef struct { ngx_str_t name; ngx_uint_t offset; ngx_http_set_header_pt handler; } ngx_http_set_header_t; struct ngx_http_header_val_s { ngx_http_complex_value_t value; ngx_str_t key; ngx_http_set_header_pt handler; ngx_uint_t offset; ngx_uint_t always; /* unsigned always:1 */ }; typedef enum { NGX_HTTP_EXPIRES_OFF, NGX_HTTP_EXPIRES_EPOCH, NGX_HTTP_EXPIRES_MAX, NGX_HTTP_EXPIRES_ACCESS, NGX_HTTP_EXPIRES_MODIFIED, NGX_HTTP_EXPIRES_DAILY, NGX_HTTP_EXPIRES_UNSET } ngx_http_expires_t; typedef struct { ngx_http_expires_t expires; time_t expires_time; ngx_http_complex_value_t *expires_value; ngx_array_t *headers; ngx_array_t *trailers; } ngx_http_headers_conf_t; static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf); static ngx_int_t ngx_http_parse_expires(ngx_str_t *value, ngx_http_expires_t *expires, time_t *expires_time, char **err); static ngx_int_t ngx_http_add_multi_header_lines(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_set_response_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static void *ngx_http_headers_create_conf(ngx_conf_t *cf); static char *ngx_http_headers_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf); static char *ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_http_set_header_t ngx_http_set_headers[] = { { ngx_string("Cache-Control"), offsetof(ngx_http_headers_out_t, cache_control), ngx_http_add_multi_header_lines }, { ngx_string("Link"), offsetof(ngx_http_headers_out_t, link), ngx_http_add_multi_header_lines }, { ngx_string("Last-Modified"), offsetof(ngx_http_headers_out_t, last_modified), ngx_http_set_last_modified }, { ngx_string("ETag"), offsetof(ngx_http_headers_out_t, etag), ngx_http_set_response_header }, { ngx_null_string, 0, NULL } }; static ngx_command_t ngx_http_headers_filter_commands[] = { { ngx_string("expires"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE12, ngx_http_headers_expires, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("add_header"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE23, ngx_http_headers_add, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_headers_conf_t, headers), NULL }, { ngx_string("add_trailer"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE23, ngx_http_headers_add, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_headers_conf_t, trailers), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_headers_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_headers_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_headers_create_conf, /* create location configuration */ ngx_http_headers_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_headers_filter_module = { NGX_MODULE_V1, &ngx_http_headers_filter_module_ctx, /* module context */ ngx_http_headers_filter_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_http_output_header_filter_pt ngx_http_next_header_filter; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_headers_filter(ngx_http_request_t *r) { ngx_str_t value; ngx_uint_t i, safe_status; ngx_http_header_val_t *h; ngx_http_headers_conf_t *conf; if (r != r->main) { return ngx_http_next_header_filter(r); } conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module); if (conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL && conf->trailers == NULL) { return ngx_http_next_header_filter(r); } switch (r->headers_out.status) { case NGX_HTTP_OK: case NGX_HTTP_CREATED: case NGX_HTTP_NO_CONTENT: case NGX_HTTP_PARTIAL_CONTENT: case NGX_HTTP_MOVED_PERMANENTLY: case NGX_HTTP_MOVED_TEMPORARILY: case NGX_HTTP_SEE_OTHER: case NGX_HTTP_NOT_MODIFIED: case NGX_HTTP_TEMPORARY_REDIRECT: case NGX_HTTP_PERMANENT_REDIRECT: safe_status = 1; break; default: safe_status = 0; break; } if (conf->expires != NGX_HTTP_EXPIRES_OFF && safe_status) { if (ngx_http_set_expires(r, conf) != NGX_OK) { return NGX_ERROR; } } if (conf->headers) { h = conf->headers->elts; for (i = 0; i < conf->headers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) { return NGX_ERROR; } if (h[i].handler(r, &h[i], &value) != NGX_OK) { return NGX_ERROR; } } } if (conf->trailers) { h = conf->trailers->elts; for (i = 0; i < conf->trailers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } r->expect_trailers = 1; break; } } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_trailers_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_str_t value; ngx_uint_t i, safe_status; ngx_chain_t *cl; ngx_table_elt_t *t; ngx_http_header_val_t *h; ngx_http_headers_conf_t *conf; conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module); if (in == NULL || conf->trailers == NULL || !r->expect_trailers || r->header_only) { return ngx_http_next_body_filter(r, in); } for (cl = in; cl; cl = cl->next) { if (cl->buf->last_buf) { break; } } if (cl == NULL) { return ngx_http_next_body_filter(r, in); } switch (r->headers_out.status) { case NGX_HTTP_OK: case NGX_HTTP_CREATED: case NGX_HTTP_NO_CONTENT: case NGX_HTTP_PARTIAL_CONTENT: case NGX_HTTP_MOVED_PERMANENTLY: case NGX_HTTP_MOVED_TEMPORARILY: case NGX_HTTP_SEE_OTHER: case NGX_HTTP_NOT_MODIFIED: case NGX_HTTP_TEMPORARY_REDIRECT: case NGX_HTTP_PERMANENT_REDIRECT: safe_status = 1; break; default: safe_status = 0; break; } h = conf->trailers->elts; for (i = 0; i < conf->trailers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) { return NGX_ERROR; } if (value.len) { t = ngx_list_push(&r->headers_out.trailers); if (t == NULL) { return NGX_ERROR; } t->key = h[i].key; t->value = value; t->hash = 1; } } return ngx_http_next_body_filter(r, in); } static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf) { char *err; size_t len; time_t now, expires_time, max_age; ngx_str_t value; ngx_int_t rc; ngx_uint_t i; ngx_table_elt_t *e, *cc, **ccp; ngx_http_expires_t expires; expires = conf->expires; expires_time = conf->expires_time; if (conf->expires_value != NULL) { if (ngx_http_complex_value(r, conf->expires_value, &value) != NGX_OK) { return NGX_ERROR; } rc = ngx_http_parse_expires(&value, &expires, &expires_time, &err); if (rc != NGX_OK) { return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_OFF) { return NGX_OK; } } e = r->headers_out.expires; if (e == NULL) { e = ngx_list_push(&r->headers_out.headers); if (e == NULL) { return NGX_ERROR; } r->headers_out.expires = e; e->hash = 1; ngx_str_set(&e->key, "Expires"); } len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT"); e->value.len = len - 1; ccp = r->headers_out.cache_control.elts; if (ccp == NULL) { if (ngx_array_init(&r->headers_out.cache_control, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } cc = ngx_list_push(&r->headers_out.headers); if (cc == NULL) { return NGX_ERROR; } cc->hash = 1; ngx_str_set(&cc->key, "Cache-Control"); ccp = ngx_array_push(&r->headers_out.cache_control); if (ccp == NULL) { return NGX_ERROR; } *ccp = cc; } else { for (i = 1; i < r->headers_out.cache_control.nelts; i++) { ccp[i]->hash = 0; } cc = ccp[0]; } if (expires == NGX_HTTP_EXPIRES_EPOCH) { e->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT"; ngx_str_set(&cc->value, "no-cache"); return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_MAX) { e->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT"; /* 10 years */ ngx_str_set(&cc->value, "max-age=315360000"); return NGX_OK; } e->value.data = ngx_pnalloc(r->pool, len); if (e->value.data == NULL) { return NGX_ERROR; } if (expires_time == 0 && expires != NGX_HTTP_EXPIRES_DAILY) { ngx_memcpy(e->value.data, ngx_cached_http_time.data, ngx_cached_http_time.len + 1); ngx_str_set(&cc->value, "max-age=0"); return NGX_OK; } now = ngx_time(); if (expires == NGX_HTTP_EXPIRES_DAILY) { expires_time = ngx_next_time(expires_time); max_age = expires_time - now; } else if (expires == NGX_HTTP_EXPIRES_ACCESS || r->headers_out.last_modified_time == -1) { max_age = expires_time; expires_time += now; } else { expires_time += r->headers_out.last_modified_time; max_age = expires_time - now; } ngx_http_time(e->value.data, expires_time); if (conf->expires_time < 0 || max_age < 0) { ngx_str_set(&cc->value, "no-cache"); return NGX_OK; } cc->value.data = ngx_pnalloc(r->pool, sizeof("max-age=") + NGX_TIME_T_LEN + 1); if (cc->value.data == NULL) { return NGX_ERROR; } cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age) - cc->value.data; return NGX_OK; } static ngx_int_t ngx_http_parse_expires(ngx_str_t *value, ngx_http_expires_t *expires, time_t *expires_time, char **err) { ngx_uint_t minus; if (*expires != NGX_HTTP_EXPIRES_MODIFIED) { if (value->len == 5 && ngx_strncmp(value->data, "epoch", 5) == 0) { *expires = NGX_HTTP_EXPIRES_EPOCH; return NGX_OK; } if (value->len == 3 && ngx_strncmp(value->data, "max", 3) == 0) { *expires = NGX_HTTP_EXPIRES_MAX; return NGX_OK; } if (value->len == 3 && ngx_strncmp(value->data, "off", 3) == 0) { *expires = NGX_HTTP_EXPIRES_OFF; return NGX_OK; } } if (value->len && value->data[0] == '@') { value->data++; value->len--; minus = 0; if (*expires == NGX_HTTP_EXPIRES_MODIFIED) { *err = "daily time cannot be used with \"modified\" parameter"; return NGX_ERROR; } *expires = NGX_HTTP_EXPIRES_DAILY; } else if (value->len && value->data[0] == '+') { value->data++; value->len--; minus = 0; } else if (value->len && value->data[0] == '-') { value->data++; value->len--; minus = 1; } else { minus = 0; } *expires_time = ngx_parse_time(value, 1); if (*expires_time == (time_t) NGX_ERROR) { *err = "invalid value"; return NGX_ERROR; } if (*expires == NGX_HTTP_EXPIRES_DAILY && *expires_time > 24 * 60 * 60) { *err = "daily time value must be less than 24 hours"; return NGX_ERROR; } if (minus) { *expires_time = - *expires_time; } return NGX_OK; } static ngx_int_t ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_table_elt_t *h; if (value->len) { h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } h->hash = 1; h->key = hv->key; h->value = *value; } return NGX_OK; } static ngx_int_t ngx_http_add_multi_header_lines(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_array_t *pa; ngx_table_elt_t *h, **ph; if (value->len == 0) { return NGX_OK; } pa = (ngx_array_t *) ((char *) &r->headers_out + hv->offset); if (pa->elts == NULL) { if (ngx_array_init(pa, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } } h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } h->hash = 1; h->key = hv->key; h->value = *value; ph = ngx_array_push(pa); if (ph == NULL) { return NGX_ERROR; } *ph = h; return NGX_OK; } static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { if (ngx_http_set_response_header(r, hv, value) != NGX_OK) { return NGX_ERROR; } r->headers_out.last_modified_time = (value->len) ? ngx_parse_http_time(value->data, value->len) : -1; return NGX_OK; } static ngx_int_t ngx_http_set_response_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_table_elt_t *h, **old; old = (ngx_table_elt_t **) ((char *) &r->headers_out + hv->offset); if (value->len == 0) { if (*old) { (*old)->hash = 0; *old = NULL; } return NGX_OK; } if (*old) { h = *old; } else { h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } *old = h; } h->hash = 1; h->key = hv->key; h->value = *value; return NGX_OK; } static void * ngx_http_headers_create_conf(ngx_conf_t *cf) { ngx_http_headers_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_headers_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->headers = NULL; * conf->trailers = NULL; * conf->expires_time = 0; * conf->expires_value = NULL; */ conf->expires = NGX_HTTP_EXPIRES_UNSET; return conf; } static char * ngx_http_headers_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_headers_conf_t *prev = parent; ngx_http_headers_conf_t *conf = child; if (conf->expires == NGX_HTTP_EXPIRES_UNSET) { conf->expires = prev->expires; conf->expires_time = prev->expires_time; conf->expires_value = prev->expires_value; if (conf->expires == NGX_HTTP_EXPIRES_UNSET) { conf->expires = NGX_HTTP_EXPIRES_OFF; } } if (conf->headers == NULL) { conf->headers = prev->headers; } if (conf->trailers == NULL) { conf->trailers = prev->trailers; } return NGX_CONF_OK; } static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_headers_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_trailers_filter; return NGX_OK; } static char * ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_headers_conf_t *hcf = conf; char *err; ngx_str_t *value; ngx_int_t rc; ngx_uint_t n; ngx_http_complex_value_t cv; ngx_http_compile_complex_value_t ccv; if (hcf->expires != NGX_HTTP_EXPIRES_UNSET) { return "is duplicate"; } value = cf->args->elts; if (cf->args->nelts == 2) { hcf->expires = NGX_HTTP_EXPIRES_ACCESS; n = 1; } else { /* cf->args->nelts == 3 */ if (ngx_strcmp(value[1].data, "modified") != 0) { return "invalid value"; } hcf->expires = NGX_HTTP_EXPIRES_MODIFIED; n = 2; } ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[n]; ccv.complex_value = &cv; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } if (cv.lengths != NULL) { hcf->expires_value = ngx_palloc(cf->pool, sizeof(ngx_http_complex_value_t)); if (hcf->expires_value == NULL) { return NGX_CONF_ERROR; } *hcf->expires_value = cv; return NGX_CONF_OK; } rc = ngx_http_parse_expires(&value[n], &hcf->expires, &hcf->expires_time, &err); if (rc != NGX_OK) { return err; } return NGX_CONF_OK; } static char * ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_headers_conf_t *hcf = conf; ngx_str_t *value; ngx_uint_t i; ngx_array_t **headers; ngx_http_header_val_t *hv; ngx_http_set_header_t *set; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; headers = (ngx_array_t **) ((char *) hcf + cmd->offset); if (*headers == NULL) { *headers = ngx_array_create(cf->pool, 1, sizeof(ngx_http_header_val_t)); if (*headers == NULL) { return NGX_CONF_ERROR; } } hv = ngx_array_push(*headers); if (hv == NULL) { return NGX_CONF_ERROR; } hv->key = value[1]; hv->handler = NULL; hv->offset = 0; hv->always = 0; if (headers == &hcf->headers) { hv->handler = ngx_http_add_header; set = ngx_http_set_headers; for (i = 0; set[i].name.len; i++) { if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) { continue; } hv->offset = set[i].offset; hv->handler = set[i].handler; break; } } if (value[2].len == 0) { ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t)); } else { ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[2]; ccv.complex_value = &hv->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } } if (cf->args->nelts == 3) { return NGX_CONF_OK; } if (ngx_strcmp(value[3].data, "always") != 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[3]); return NGX_CONF_ERROR; } hv->always = 1; return NGX_CONF_OK; }