Mercurial > hg > nginx
view src/http/modules/ngx_http_browser_module.c @ 9203:0de20f43db25
Fixed request termination with AIO and subrequests (ticket #2555).
When a request was terminated due to an error via ngx_http_terminate_request()
while an AIO operation was running in a subrequest, various issues were
observed. This happened because ngx_http_request_finalizer() was only set
in the subrequest where ngx_http_terminate_request() was called, but not
in the subrequest where the AIO operation was running. After completion
of the AIO operation normal processing of the subrequest was resumed, leading
to issues.
In particular, in case of the upstream module, termination of the request
called upstream cleanup, which closed the upstream connection. Attempts to
further work with the upstream connection after AIO operation completion
resulted in segfaults in ngx_ssl_recv(), "readv() failed (9: Bad file
descriptor) while reading upstream" errors, or socket leaks.
In ticket #2555, issues were observed with the following configuration
with cache background update (with thread writing instrumented to
introduce a delay, when a client closes the connection during an update):
location = /background-and-aio-write {
proxy_pass ...
proxy_cache one;
proxy_cache_valid 200 1s;
proxy_cache_background_update on;
proxy_cache_use_stale updating;
aio threads;
aio_write on;
limit_rate 1000;
}
Similarly, the same issue can be seen with SSI, and can be caused by
errors in subrequests, such as in the following configuration
(where "/proxy" uses AIO, and "/sleep" returns 444 after some delay,
causing request termination):
location = /ssi-active-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/proxy" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Or the same with both AIO operation and the error in non-active subrequests
(which needs slightly different handling, see below):
location = /ssi-non-active-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static" -->
<!--#include virtual="/proxy" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Similarly, issues can be observed with just static files. However,
with static files potential impact is limited due to timeout safeguards
in ngx_http_writer(), and the fact that c->error is set during request
termination.
In a simple configuration with an AIO operation in the active subrequest,
such as in the following configuration, the connection is closed right
after completion of the AIO operation anyway, since ngx_http_writer()
tries to write to the connection and fails due to c->error set:
location = /ssi-active-static-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static-aio" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
In the following configuration, with an AIO operation in a non-active
subrequest, the connection is closed only after send_timeout expires:
location = /ssi-non-active-static-boom {
ssi on;
ssi_types *;
return 200 '
<!--#include virtual="/static" -->
<!--#include virtual="/static-aio" -->
<!--#include virtual="/sleep" -->
';
limit_rate 1000;
}
Fix is to introduce r->main->terminated flag, which is to be checked
by AIO event handlers when the r->main->blocked counter is decremented.
When the flag is set, handlers are expected to wake up the connection
instead of the subrequest (which might be already cleaned up).
Additionally, now ngx_http_request_finalizer() is always set in the
active subrequest, so waking up the connection properly finalizes the
request even if termination happened in a non-active subrequest.
| author | Maxim Dounin <mdounin@mdounin.ru> |
|---|---|
| date | Tue, 30 Jan 2024 03:20:05 +0300 |
| parents | 2a288909abc6 |
| children |
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> /* * The module can check browser versions conforming to the following formats: * X, X.X, X.X.X, and X.X.X.X. The maximum values of each format may be * 4000, 4000.99, 4000.99.99, and 4000.99.99.99. */ #define NGX_HTTP_MODERN_BROWSER 0 #define NGX_HTTP_ANCIENT_BROWSER 1 typedef struct { u_char browser[12]; size_t skip; size_t add; u_char name[12]; } ngx_http_modern_browser_mask_t; typedef struct { ngx_uint_t version; size_t skip; size_t add; u_char name[12]; } ngx_http_modern_browser_t; typedef struct { ngx_array_t *modern_browsers; ngx_array_t *ancient_browsers; ngx_http_variable_value_t *modern_browser_value; ngx_http_variable_value_t *ancient_browser_value; unsigned modern_unlisted_browsers:1; unsigned netscape4:1; } ngx_http_browser_conf_t; static ngx_int_t ngx_http_msie_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_http_browser_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_uint_t ngx_http_browser(ngx_http_request_t *r, ngx_http_browser_conf_t *cf); static ngx_int_t ngx_http_browser_add_variables(ngx_conf_t *cf); static void *ngx_http_browser_create_conf(ngx_conf_t *cf); static char *ngx_http_browser_merge_conf(ngx_conf_t *cf, void *parent, void *child); static int ngx_libc_cdecl ngx_http_modern_browser_sort(const void *one, const void *two); static char *ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_browser_commands[] = { { ngx_string("modern_browser"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE12, ngx_http_modern_browser, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("ancient_browser"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_1MORE, ngx_http_ancient_browser, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("modern_browser_value"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_modern_browser_value, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("ancient_browser_value"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_ancient_browser_value, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_browser_module_ctx = { ngx_http_browser_add_variables, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_browser_create_conf, /* create location configuration */ ngx_http_browser_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_browser_module = { NGX_MODULE_V1, &ngx_http_browser_module_ctx, /* module context */ ngx_http_browser_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_modern_browser_mask_t ngx_http_modern_browser_masks[] = { /* Opera must be the first browser to check */ /* * "Opera/7.50 (X11; FreeBSD i386; U) [en]" * "Mozilla/5.0 (X11; FreeBSD i386; U) Opera 7.50 [en]" * "Mozilla/4.0 (compatible; MSIE 6.0; X11; FreeBSD i386) Opera 7.50 [en]" * "Opera/8.0 (Windows NT 5.1; U; ru)" * "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0; en) Opera 8.0" * "Opera/9.01 (X11; FreeBSD 6 i386; U; en)" */ { "opera", 0, sizeof("Opera ") - 1, "Opera"}, /* "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)" */ { "msie", sizeof("Mozilla/4.0 (compatible; ") - 1, sizeof("MSIE ") - 1, "MSIE "}, /* * "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.0.0) Gecko/20020610" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.5) Gecko/20031006" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.6) Gecko/20040206 * Firefox/0.8" * "Mozilla/5.0 (Windows; U; Windows NT 5.1; ru-RU; rv:1.7.8) * Gecko/20050511 Firefox/1.0.4" * "Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.8.0.5) Gecko/20060729 * Firefox/1.5.0.5" */ { "gecko", sizeof("Mozilla/5.0 (") - 1, sizeof("rv:") - 1, "rv:"}, /* * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/125.2 * (KHTML, like Gecko) Safari/125.7" * "Mozilla/5.0 (SymbianOS/9.1; U; en-us) AppleWebKit/413 * (KHTML, like Gecko) Safari/413" * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en) AppleWebKit/418 * (KHTML, like Gecko) Safari/417.9.3" * "Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ru-ru) AppleWebKit/418.8 * (KHTML, like Gecko) Safari/419.3" */ { "safari", sizeof("Mozilla/5.0 (") - 1, sizeof("Safari/") - 1, "Safari/"}, /* * "Mozilla/5.0 (compatible; Konqueror/3.1; Linux)" * "Mozilla/5.0 (compatible; Konqueror/3.4; Linux) KHTML/3.4.2 (like Gecko)" * "Mozilla/5.0 (compatible; Konqueror/3.5; FreeBSD) KHTML/3.5.1 * (like Gecko)" */ { "konqueror", sizeof("Mozilla/5.0 (compatible; ") - 1, sizeof("Konqueror/") - 1, "Konqueror/"}, { "", 0, 0, "" } }; static ngx_http_variable_t ngx_http_browser_vars[] = { { ngx_string("msie"), NULL, ngx_http_msie_variable, 0, NGX_HTTP_VAR_CHANGEABLE, 0 }, { ngx_string("modern_browser"), NULL, ngx_http_browser_variable, NGX_HTTP_MODERN_BROWSER, NGX_HTTP_VAR_CHANGEABLE, 0 }, { ngx_string("ancient_browser"), NULL, ngx_http_browser_variable, NGX_HTTP_ANCIENT_BROWSER, NGX_HTTP_VAR_CHANGEABLE, 0 }, ngx_http_null_variable }; static ngx_int_t ngx_http_browser_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_uint_t rc; ngx_http_browser_conf_t *cf; cf = ngx_http_get_module_loc_conf(r, ngx_http_browser_module); rc = ngx_http_browser(r, cf); if (data == NGX_HTTP_MODERN_BROWSER && rc == NGX_HTTP_MODERN_BROWSER) { *v = *cf->modern_browser_value; return NGX_OK; } if (data == NGX_HTTP_ANCIENT_BROWSER && rc == NGX_HTTP_ANCIENT_BROWSER) { *v = *cf->ancient_browser_value; return NGX_OK; } *v = ngx_http_variable_null_value; return NGX_OK; } static ngx_uint_t ngx_http_browser(ngx_http_request_t *r, ngx_http_browser_conf_t *cf) { size_t len; u_char *name, *ua, *last, c; ngx_str_t *ancient; ngx_uint_t i, version, ver, scale; ngx_http_modern_browser_t *modern; if (r->headers_in.user_agent == NULL) { if (cf->modern_unlisted_browsers) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } ua = r->headers_in.user_agent->value.data; len = r->headers_in.user_agent->value.len; last = ua + len; if (cf->modern_browsers) { modern = cf->modern_browsers->elts; for (i = 0; i < cf->modern_browsers->nelts; i++) { name = ua + modern[i].skip; if (name >= last) { continue; } name = (u_char *) ngx_strstr(name, modern[i].name); if (name == NULL) { continue; } ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "browser: \"%s\"", name); name += modern[i].add; if (name >= last) { continue; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%s\"", modern[i].version, name); version = 0; ver = 0; scale = 1000000; while (name < last) { c = *name++; if (c >= '0' && c <= '9') { ver = ver * 10 + (c - '0'); continue; } if (c == '.') { version += ver * scale; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%ui\"", modern[i].version, version); if (version > modern[i].version) { return NGX_HTTP_MODERN_BROWSER; } ver = 0; scale /= 100; continue; } break; } version += ver * scale; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "version: \"%ui\" \"%ui\"", modern[i].version, version); if (version >= modern[i].version) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } if (!cf->modern_unlisted_browsers) { return NGX_HTTP_ANCIENT_BROWSER; } } if (cf->netscape4) { if (len > sizeof("Mozilla/4.72 ") - 1 && ngx_strncmp(ua, "Mozilla/", sizeof("Mozilla/") - 1) == 0 && ua[8] > '0' && ua[8] < '5') { return NGX_HTTP_ANCIENT_BROWSER; } } if (cf->ancient_browsers) { ancient = cf->ancient_browsers->elts; for (i = 0; i < cf->ancient_browsers->nelts; i++) { if (len >= ancient[i].len && ngx_strstr(ua, ancient[i].data) != NULL) { return NGX_HTTP_ANCIENT_BROWSER; } } } if (cf->modern_unlisted_browsers) { return NGX_HTTP_MODERN_BROWSER; } return NGX_HTTP_ANCIENT_BROWSER; } static ngx_int_t ngx_http_msie_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { if (r->headers_in.msie) { *v = ngx_http_variable_true_value; return NGX_OK; } *v = ngx_http_variable_null_value; return NGX_OK; } static ngx_int_t ngx_http_browser_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var, *v; for (v = ngx_http_browser_vars; v->name.len; v++) { var = ngx_http_add_variable(cf, &v->name, v->flags); if (var == NULL) { return NGX_ERROR; } var->get_handler = v->get_handler; var->data = v->data; } return NGX_OK; } static void * ngx_http_browser_create_conf(ngx_conf_t *cf) { ngx_http_browser_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_browser_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->modern_browsers = NULL; * conf->ancient_browsers = NULL; * conf->modern_browser_value = NULL; * conf->ancient_browser_value = NULL; * * conf->modern_unlisted_browsers = 0; * conf->netscape4 = 0; */ return conf; } static char * ngx_http_browser_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_browser_conf_t *prev = parent; ngx_http_browser_conf_t *conf = child; ngx_uint_t i, n; ngx_http_modern_browser_t *browsers, *opera; /* * At the merge the skip field is used to store the browser slot, * it will be used in sorting and then will overwritten * with a real skip value. The zero value means Opera. */ if (conf->modern_browsers == NULL && conf->modern_unlisted_browsers == 0) { conf->modern_browsers = prev->modern_browsers; conf->modern_unlisted_browsers = prev->modern_unlisted_browsers; } else if (conf->modern_browsers != NULL) { browsers = conf->modern_browsers->elts; for (i = 0; i < conf->modern_browsers->nelts; i++) { if (browsers[i].skip == 0) { goto found; } } /* * Opera may contain MSIE string, so if Opera was not enumerated * as modern browsers, then add it and set a unreachable version */ opera = ngx_array_push(conf->modern_browsers); if (opera == NULL) { return NGX_CONF_ERROR; } opera->skip = 0; opera->version = 4001000000U; browsers = conf->modern_browsers->elts; found: ngx_qsort(browsers, (size_t) conf->modern_browsers->nelts, sizeof(ngx_http_modern_browser_t), ngx_http_modern_browser_sort); for (i = 0; i < conf->modern_browsers->nelts; i++) { n = browsers[i].skip; browsers[i].skip = ngx_http_modern_browser_masks[n].skip; browsers[i].add = ngx_http_modern_browser_masks[n].add; (void) ngx_cpystrn(browsers[i].name, ngx_http_modern_browser_masks[n].name, 12); } } if (conf->ancient_browsers == NULL && conf->netscape4 == 0) { conf->ancient_browsers = prev->ancient_browsers; conf->netscape4 = prev->netscape4; } if (conf->modern_browser_value == NULL) { conf->modern_browser_value = prev->modern_browser_value; } if (conf->modern_browser_value == NULL) { conf->modern_browser_value = &ngx_http_variable_true_value; } if (conf->ancient_browser_value == NULL) { conf->ancient_browser_value = prev->ancient_browser_value; } if (conf->ancient_browser_value == NULL) { conf->ancient_browser_value = &ngx_http_variable_true_value; } return NGX_CONF_OK; } static int ngx_libc_cdecl ngx_http_modern_browser_sort(const void *one, const void *two) { ngx_http_modern_browser_t *first = (ngx_http_modern_browser_t *) one; ngx_http_modern_browser_t *second = (ngx_http_modern_browser_t *) two; return (first->skip - second->skip); } static char * ngx_http_modern_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; u_char c; ngx_str_t *value; ngx_uint_t i, n, version, ver, scale; ngx_http_modern_browser_t *browser; ngx_http_modern_browser_mask_t *mask; value = cf->args->elts; if (cf->args->nelts == 2) { if (ngx_strcmp(value[1].data, "unlisted") == 0) { bcf->modern_unlisted_browsers = 1; return NGX_CONF_OK; } return NGX_CONF_ERROR; } if (bcf->modern_browsers == NULL) { bcf->modern_browsers = ngx_array_create(cf->pool, 5, sizeof(ngx_http_modern_browser_t)); if (bcf->modern_browsers == NULL) { return NGX_CONF_ERROR; } } browser = ngx_array_push(bcf->modern_browsers); if (browser == NULL) { return NGX_CONF_ERROR; } mask = ngx_http_modern_browser_masks; for (n = 0; mask[n].browser[0] != '\0'; n++) { if (ngx_strcasecmp(mask[n].browser, value[1].data) == 0) { goto found; } } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown browser name \"%V\"", &value[1]); return NGX_CONF_ERROR; found: /* * at this stage the skip field is used to store the browser slot, * it will be used in sorting in merge stage and then will overwritten * with a real value */ browser->skip = n; version = 0; ver = 0; scale = 1000000; for (i = 0; i < value[2].len; i++) { c = value[2].data[i]; if (c >= '0' && c <= '9') { ver = ver * 10 + (c - '0'); continue; } if (c == '.') { version += ver * scale; ver = 0; scale /= 100; continue; } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid browser version \"%V\"", &value[2]); return NGX_CONF_ERROR; } version += ver * scale; browser->version = version; return NGX_CONF_OK; } static char * ngx_http_ancient_browser(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value, *browser; ngx_uint_t i; value = cf->args->elts; for (i = 1; i < cf->args->nelts; i++) { if (ngx_strcmp(value[i].data, "netscape4") == 0) { bcf->netscape4 = 1; continue; } if (bcf->ancient_browsers == NULL) { bcf->ancient_browsers = ngx_array_create(cf->pool, 4, sizeof(ngx_str_t)); if (bcf->ancient_browsers == NULL) { return NGX_CONF_ERROR; } } browser = ngx_array_push(bcf->ancient_browsers); if (browser == NULL) { return NGX_CONF_ERROR; } *browser = value[i]; } return NGX_CONF_OK; } static char * ngx_http_modern_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value; bcf->modern_browser_value = ngx_palloc(cf->pool, sizeof(ngx_http_variable_value_t)); if (bcf->modern_browser_value == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; bcf->modern_browser_value->len = value[1].len; bcf->modern_browser_value->valid = 1; bcf->modern_browser_value->no_cacheable = 0; bcf->modern_browser_value->not_found = 0; bcf->modern_browser_value->data = value[1].data; return NGX_CONF_OK; } static char * ngx_http_ancient_browser_value(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_browser_conf_t *bcf = conf; ngx_str_t *value; bcf->ancient_browser_value = ngx_palloc(cf->pool, sizeof(ngx_http_variable_value_t)); if (bcf->ancient_browser_value == NULL) { return NGX_CONF_ERROR; } value = cf->args->elts; bcf->ancient_browser_value->len = value[1].len; bcf->ancient_browser_value->valid = 1; bcf->ancient_browser_value->no_cacheable = 0; bcf->ancient_browser_value->not_found = 0; bcf->ancient_browser_value->data = value[1].data; return NGX_CONF_OK; }