gRPC: generate error when response size is wrong. As long as the "Content-Length" header is given, we now make sure it exactly matches the size of the response. If it doesn't, the response is considered malformed and must not be forwarded (https://tools.ietf.org/html/rfc7540#section-8.1.2.6). While it is not really possible to "not forward" the response which is already being forwarded, we generate an error instead, which is the closest equivalent. Previous behaviour was to pass everything to the client, but this seems to be suboptimal and causes issues (ticket #1695). Also this directly contradicts HTTP/2 specification requirements. Note that the new behaviour for the gRPC proxy is more strict than that applied in other variants of proxying. This is intentional, as HTTP/2 specification requires us to do so, while in other types of proxying malformed responses from backends are well known and historically tolerated.

/*
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_SYSLOG_H_INCLUDED_
#define _NGX_SYSLOG_H_INCLUDED_


typedef struct {
    ngx_uint_t        facility;
    ngx_uint_t        severity;
    ngx_str_t         tag;

    ngx_addr_t        server;
    ngx_connection_t  conn;
    unsigned          busy:1;
    unsigned          nohostname:1;
} ngx_syslog_peer_t;


char *ngx_syslog_process_conf(ngx_conf_t *cf, ngx_syslog_peer_t *peer);
u_char *ngx_syslog_add_header(ngx_syslog_peer_t *peer, u_char *buf);
void ngx_syslog_writer(ngx_log_t *log, ngx_uint_t level, u_char *buf,
    size_t len);
ssize_t ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len);


#endif /* _NGX_SYSLOG_H_INCLUDED_ */