[PATCH] Adds $orig_remote_addr in realip module

[Ruslan Ermilov]

On Thu, May 28, 2015 at 04:39:08PM -0500, Jon Nalley wrote:
> # HG changeset patch
> # User Jon Nalley <code at bluebot.org>
> # Date 1432848566 18000
> #      Thu May 28 16:29:26 2015 -0500
> # Node ID 4e59c130d468ee6757b5ba97f912b6c72c3f7c0d
> # Parent  0a096e2e51fcbb536007d94bf3edfc308e214f56
> Adds $orig_remote_addr in realip module.
> 
> When the realip module sets $remote_addr, the connecting IP is
> no longer available for logging etc.  This change preserves the
> connecting IP as $orig_remote_addr.
> 
> diff -r 0a096e2e51fc -r 4e59c130d468 src/http/modules/ngx_http_realip_module.c
> --- a/src/http/modules/ngx_http_realip_module.c	Tue May 26 16:49:51 2015 +0300
> +++ b/src/http/modules/ngx_http_realip_module.c	Thu May 28 16:29:26 2015 -0500
> @@ -33,6 +33,10 @@
>  } ngx_http_realip_ctx_t;
>  
>  
> +static ngx_int_t
> +    ngx_http_realip_orig_remote_addr_variable(ngx_http_request_t *r,
> +    ngx_http_variable_value_t *v, uintptr_t data);
> +static ngx_int_t ngx_http_realip_add_variables(ngx_conf_t *cf);
>  static ngx_int_t ngx_http_realip_handler(ngx_http_request_t *r);
>  static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r,
>      ngx_addr_t *addr);
> @@ -75,7 +79,7 @@
>  
>  
>  static ngx_http_module_t  ngx_http_realip_module_ctx = {
> -    NULL,                                  /* preconfiguration */
> +    ngx_http_realip_add_variables,         /* preconfiguration */
>      ngx_http_realip_init,                  /* postconfiguration */
>  
>      NULL,                                  /* create main configuration */
> @@ -105,6 +109,15 @@
>  };
>  
>  
> +static ngx_http_variable_t  ngx_http_realip_vars[] = {
> +
> +    { ngx_string("orig_remote_addr"), NULL,
> +      ngx_http_realip_orig_remote_addr_variable, 0, NGX_HTTP_VAR_NOHASH, 0 },
> +
> +    { ngx_null_string, NULL, NULL, 0, 0, 0 }
> +};
> +
> +
>  static ngx_int_t
>  ngx_http_realip_handler(ngx_http_request_t *r)
>  {
> @@ -369,6 +382,48 @@
>  }
>  
>  
> +static ngx_int_t
> +ngx_http_realip_orig_remote_addr_variable(ngx_http_request_t *r,
> +    ngx_http_variable_value_t *v, uintptr_t data)
> +{
> +    ngx_http_realip_ctx_t *ctx;
> +
> +    ctx = ngx_http_get_module_ctx(r, ngx_http_realip_module);

Contexts are lost with at least internal redirects and redirects
to named locations, so this approach won't work, unfortunately.

    /* clear the modules contexts */
    ngx_memzero(r->ctx, sizeof(void *) * ngx_http_max_module);


> +
> +    if (ctx == NULL) {
> +        v->not_found = 1;
> +        return NGX_OK;
> +    }
> +
> +    v->len = ctx->addr_text.len;
> +    v->valid = 1;
> +    v->no_cacheable = 0;
> +    v->not_found = 0;
> +    v->data = ctx->addr_text.data;
> +
> +    return NGX_OK;
> +}
> +
> +
> +static ngx_int_t
> +ngx_http_realip_add_variables(ngx_conf_t *cf)
> +{
> +    ngx_http_variable_t  *var, *v;
> +
> +    for (v = ngx_http_realip_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_realip_create_loc_conf(ngx_conf_t *cf)
>  {