Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_secure_link_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 | c7d4017c8876 |
children | bdd4d89370a7 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #include <ngx_md5.h> typedef struct { ngx_http_complex_value_t *variable; ngx_http_complex_value_t *md5; ngx_str_t secret; } ngx_http_secure_link_conf_t; typedef struct { ngx_str_t expires; } ngx_http_secure_link_ctx_t; static ngx_int_t ngx_http_secure_link_old_variable(ngx_http_request_t *r, ngx_http_secure_link_conf_t *conf, ngx_http_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_http_secure_link_expires_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static void *ngx_http_secure_link_create_conf(ngx_conf_t *cf); static char *ngx_http_secure_link_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_secure_link_add_variables(ngx_conf_t *cf); static ngx_command_t ngx_http_secure_link_commands[] = { { ngx_string("secure_link"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_set_complex_value_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_secure_link_conf_t, variable), NULL }, { ngx_string("secure_link_md5"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_set_complex_value_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_secure_link_conf_t, md5), NULL }, { ngx_string("secure_link_secret"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_conf_set_str_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_secure_link_conf_t, secret), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_secure_link_module_ctx = { ngx_http_secure_link_add_variables, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_secure_link_create_conf, /* create location configuration */ ngx_http_secure_link_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_secure_link_module = { NGX_MODULE_V1, &ngx_http_secure_link_module_ctx, /* module context */ ngx_http_secure_link_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_str_t ngx_http_secure_link_name = ngx_string("secure_link"); static ngx_str_t ngx_http_secure_link_expires_name = ngx_string("secure_link_expires"); static ngx_int_t ngx_http_secure_link_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { u_char *p, *last; ngx_str_t val, hash; time_t expires; ngx_md5_t md5; ngx_http_secure_link_ctx_t *ctx; ngx_http_secure_link_conf_t *conf; u_char hash_buf[18], md5_buf[16]; conf = ngx_http_get_module_loc_conf(r, ngx_http_secure_link_module); if (conf->secret.data) { return ngx_http_secure_link_old_variable(r, conf, v, data); } if (conf->variable == NULL || conf->md5 == NULL) { goto not_found; } if (ngx_http_complex_value(r, conf->variable, &val) != NGX_OK) { return NGX_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "secure link: \"%V\"", &val); last = val.data + val.len; p = ngx_strlchr(val.data, last, ','); expires = 0; if (p) { val.len = p++ - val.data; expires = ngx_atotm(p, last - p); if (expires <= 0) { goto not_found; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_secure_link_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_secure_link_module); ctx->expires.len = last - p; ctx->expires.data = p; } if (val.len > 24) { goto not_found; } hash.data = hash_buf; if (ngx_decode_base64url(&hash, &val) != NGX_OK) { goto not_found; } if (hash.len != 16) { goto not_found; } if (ngx_http_complex_value(r, conf->md5, &val) != NGX_OK) { return NGX_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "secure link md5: \"%V\"", &val); ngx_md5_init(&md5); ngx_md5_update(&md5, val.data, val.len); ngx_md5_final(md5_buf, &md5); if (ngx_memcmp(hash_buf, md5_buf, 16) != 0) { goto not_found; } v->data = (u_char *) ((expires && expires < ngx_time()) ? "0" : "1"); v->len = 1; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; return NGX_OK; not_found: v->not_found = 1; return NGX_OK; } static ngx_int_t ngx_http_secure_link_old_variable(ngx_http_request_t *r, ngx_http_secure_link_conf_t *conf, ngx_http_variable_value_t *v, uintptr_t data) { u_char *p, *start, *end, *last; size_t len; ngx_int_t n; ngx_uint_t i; ngx_md5_t md5; u_char hash[16]; p = &r->unparsed_uri.data[1]; last = r->unparsed_uri.data + r->unparsed_uri.len; while (p < last) { if (*p++ == '/') { start = p; goto md5_start; } } goto not_found; md5_start: while (p < last) { if (*p++ == '/') { end = p - 1; goto url_start; } } goto not_found; url_start: len = last - p; if (end - start != 32 || len == 0) { goto not_found; } ngx_md5_init(&md5); ngx_md5_update(&md5, p, len); ngx_md5_update(&md5, conf->secret.data, conf->secret.len); ngx_md5_final(hash, &md5); for (i = 0; i < 16; i++) { n = ngx_hextoi(&start[2 * i], 2); if (n == NGX_ERROR || n != hash[i]) { goto not_found; } } v->len = len; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->data = p; return NGX_OK; not_found: v->not_found = 1; return NGX_OK; } static ngx_int_t ngx_http_secure_link_expires_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_http_secure_link_ctx_t *ctx; ctx = ngx_http_get_module_ctx(r, ngx_http_secure_link_module); if (ctx) { v->len = ctx->expires.len; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->data = ctx->expires.data; } else { v->not_found = 1; } return NGX_OK; } static void * ngx_http_secure_link_create_conf(ngx_conf_t *cf) { ngx_http_secure_link_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_secure_link_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->variable = NULL; * conf->md5 = NULL; * conf->secret = { 0, NULL }; */ return conf; } static char * ngx_http_secure_link_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_secure_link_conf_t *prev = parent; ngx_http_secure_link_conf_t *conf = child; if (conf->secret.data) { if (conf->variable || conf->md5) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"secure_link_secret\" cannot be mixed with " "\"secure_link\" and \"secure_link_md5\""); return NGX_CONF_ERROR; } return NGX_CONF_OK; } if (conf->variable == NULL) { conf->variable = prev->variable; } if (conf->md5 == NULL) { conf->md5 = prev->md5; } if (conf->variable == NULL && conf->md5 == NULL) { conf->secret = prev->secret; } return NGX_CONF_OK; } static ngx_int_t ngx_http_secure_link_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var; var = ngx_http_add_variable(cf, &ngx_http_secure_link_name, 0); if (var == NULL) { return NGX_ERROR; } var->get_handler = ngx_http_secure_link_variable; var = ngx_http_add_variable(cf, &ngx_http_secure_link_expires_name, 0); if (var == NULL) { return NGX_ERROR; } var->get_handler = ngx_http_secure_link_expires_variable; return NGX_OK; }