Upstream: better handling of invalid headers in cache files.

If cache file is truncated, it is possible that u->process_header()
will return NGX_AGAIN.  Added appropriate handling of this case by
changing the error to NGX_HTTP_UPSTREAM_INVALID_HEADER.

Also, added appropriate logging of this and NGX_HTTP_UPSTREAM_INVALID_HEADER
cases at the "crit" level.  Note that this will result in duplicate logging
in case of NGX_HTTP_UPSTREAM_INVALID_HEADER.  While this is something better
to avoid, it is considered to be an overkill to implement cache-specific
error logging in u->process_header().

Additionally, u->buffer.start is now reset to be able to receive a new
response, and u->cache_status set to MISS to provide the value in the
$upstream_cache_status variable, much like it happens on other cache file
errors detected by ngx_http_file_cache_read(), instead of HIT, which is
believed to be misleading.
This commit is contained in:
Maxim Dounin 2017-10-02 19:10:20 +03:00
parent e22f5b71fe
commit 105dd42bd7

View File

@ -582,6 +582,8 @@ ngx_http_upstream_init_request(ngx_http_request_t *r)
if (rc == NGX_HTTP_UPSTREAM_INVALID_HEADER) {
rc = NGX_DECLINED;
r->cached = 0;
u->buffer.start = NULL;
u->cache_status = NGX_HTTP_CACHE_MISS;
}
if (ngx_http_upstream_cache_background_update(r, u) != NGX_OK) {
@ -1059,8 +1061,16 @@ ngx_http_upstream_cache_send(ngx_http_request_t *r, ngx_http_upstream_t *u)
return NGX_ERROR;
}
if (rc == NGX_AGAIN) {
rc = NGX_HTTP_UPSTREAM_INVALID_HEADER;
}
/* rc == NGX_HTTP_UPSTREAM_INVALID_HEADER */
ngx_log_error(NGX_LOG_CRIT, r->connection->log, 0,
"cache file \"%s\" contains invalid header",
c->file.name.data);
/* TODO: delete file */
return rc;